TM4C1294NCPDTI3R

TE X AS I NS TRUM E NTS - P RO DUCTION D ATA Tiva™ TM4C1294NCPDT Microcontroller D ATA SH E E T D S -T M 4C 1294 NCP DT - 1 5 8 6 3 . 2 7 4 3 S P M S 433B C o p yri g h t © 2 0 07-2014 Te xa s In stru me n ts In co rporated Copyright Copyright © 2007-2014 Texas Instruments Incorporated. Tiva and TivaWare are trademarks of Texas Instruments Incorporated. ARM and Thumb are registered trademarks and Cortex is a trademark of ARM Limited. All other trademarks are the property of others. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. 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About This Manual ................................................................................................................................ Related Documents ............................................................................................................................... Documentation Conventions .................................................................................................................. 48 48 48 49 1 Architectural Overview .......................................................................................... 51 1.1 1.2 1.3 1.3.1 1.3.2 1.3.3 1.3.4 1.3.5 1.3.6 1.3.7 1.3.8 1.3.9 1.3.10 1.4 1.5 1.6 Tiva™ C Series Overview .............................................................................................. 51 TM4C1294NCPDT Microcontroller Overview .................................................................. 52 TM4C1294NCPDT Microcontroller Features ................................................................... 55 ARM Cortex-M4F Processor Core .................................................................................. 55 On-Chip Memory ........................................................................................................... 57 External Peripheral Interface ......................................................................................... 59 Cyclical Redundancy Check (CRC) ............................................................................... 61 Serial Communications Peripherals ................................................................................ 61 System Integration ........................................................................................................ 67 Advanced Motion Control ............................................................................................... 74 Analog .......................................................................................................................... 76 JTAG and ARM Serial Wire Debug ................................................................................ 78 Packaging and Temperature .......................................................................................... 78 TM4C1294NCPDT Microcontroller Hardware Details ....................................................... 78 Kits .............................................................................................................................. 79 Support Information ....................................................................................................... 79 2 The Cortex-M4F Processor ................................................................................... 80 2.1 2.2 2.2.1 2.2.2 2.2.3 2.2.4 2.3 2.3.1 2.3.2 2.3.3 2.3.4 2.3.5 2.3.6 2.4 2.4.1 2.4.2 2.4.3 2.4.4 2.4.5 2.4.6 2.4.7 Block Diagram .............................................................................................................. 81 Overview ...................................................................................................................... 82 System-Level Interface .................................................................................................. 82 Integrated Configurable Debug ...................................................................................... 82 Trace Port Interface Unit (TPIU) ..................................................................................... 83 Cortex-M4F System Component Details ......................................................................... 83 Programming Model ...................................................................................................... 84 Processor Mode and Privilege Levels for Software Execution ........................................... 84 Stacks .......................................................................................................................... 85 Register Map ................................................................................................................ 85 Register Descriptions .................................................................................................... 87 Exceptions and Interrupts ............................................................................................ 103 Data Types ................................................................................................................. 103 Memory Model ............................................................................................................ 103 Memory Regions, Types and Attributes ......................................................................... 106 Memory System Ordering of Memory Accesses ............................................................ 107 Behavior of Memory Accesses ..................................................................................... 107 Software Ordering of Memory Accesses ....................................................................... 108 Bit-Banding ................................................................................................................. 109 Data Storage .............................................................................................................. 111 Synchronization Primitives ........................................................................................... 112 June 18, 2014 3 Texas Instruments-Production Data Table of Contents 2.5 2.5.1 2.5.2 2.5.3 2.5.4 2.5.5 2.5.6 2.5.7 2.6 2.6.1 2.6.2 2.6.3 2.6.4 2.7 2.7.1 2.7.2 2.8 Exception Model ......................................................................................................... Exception States ......................................................................................................... Exception Types .......................................................................................................... Exception Handlers ..................................................................................................... Vector Table ................................................................................................................ Exception Priorities ...................................................................................................... Interrupt Priority Grouping ............................................................................................ Exception Entry and Return ......................................................................................... Fault Handling ............................................................................................................. Fault Types ................................................................................................................. Fault Escalation and Hard Faults .................................................................................. Fault Status Registers and Fault Address Registers ...................................................... Lockup ....................................................................................................................... Power Management .................................................................................................... Entering Sleep Modes ................................................................................................. Wake Up from Sleep Mode .......................................................................................... Instruction Set Summary .............................................................................................. 113 114 114 119 119 120 120 120 123 124 124 125 125 126 126 126 127 3 Cortex-M4 Peripherals ......................................................................................... 134 3.1 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5 3.2 3.3 3.4 3.5 3.6 3.7 Functional Description ................................................................................................. 134 System Timer (SysTick) ............................................................................................... 135 Nested Vectored Interrupt Controller (NVIC) .................................................................. 136 System Control Block (SCB) ........................................................................................ 137 Memory Protection Unit (MPU) ..................................................................................... 137 Floating-Point Unit (FPU) ............................................................................................. 142 Register Map .............................................................................................................. 146 System Timer (SysTick) Register Descriptions .............................................................. 149 NVIC Register Descriptions .......................................................................................... 153 System Control Block (SCB) Register Descriptions ........................................................ 163 Memory Protection Unit (MPU) Register Descriptions .................................................... 192 Floating-Point Unit (FPU) Register Descriptions ............................................................ 201 4 JTAG Interface ...................................................................................................... 207 4.1 4.2 4.3 4.3.1 4.3.2 4.3.3 4.3.4 4.4 4.5 4.5.1 4.5.2 Block Diagram ............................................................................................................ Signal Description ....................................................................................................... Functional Description ................................................................................................. JTAG Interface Pins ..................................................................................................... JTAG TAP Controller ................................................................................................... Shift Registers ............................................................................................................ Operational Considerations .......................................................................................... Initialization and Configuration ..................................................................................... Register Descriptions .................................................................................................. Instruction Register (IR) ............................................................................................... Data Registers ............................................................................................................ 208 208 209 209 211 212 212 215 215 216 217 5 System Control ..................................................................................................... 220 5.1 5.2 5.2.1 5.2.2 5.2.3 Signal Description ....................................................................................................... Functional Description ................................................................................................. Device Identification .................................................................................................... Reset Control .............................................................................................................. Non-Maskable Interrupt ............................................................................................... 4 220 220 220 221 228 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 5.2.4 5.2.5 5.2.6 5.3 5.4 5.5 Power Control ............................................................................................................. Clock Control .............................................................................................................. System Control ........................................................................................................... Initialization and Configuration ..................................................................................... Register Map .............................................................................................................. System Control Register Descriptions (System Control Offset) ....................................... 229 230 239 246 247 254 6 Processor Support and Exception Module ........................................................ 523 6.1 6.2 6.3 Functional Description ................................................................................................. 523 Register Map .............................................................................................................. 523 Register Descriptions .................................................................................................. 523 7 Hibernation Module .............................................................................................. 531 7.1 7.2 7.3 7.3.1 7.3.2 7.3.3 7.3.4 7.3.5 7.3.6 7.3.7 7.3.8 7.3.9 7.3.10 7.3.11 7.3.12 7.3.13 7.4 7.4.1 7.4.2 7.4.3 7.4.4 7.4.5 7.4.6 7.5 7.6 Block Diagram ............................................................................................................ 533 Signal Description ....................................................................................................... 533 Functional Description ................................................................................................. 534 Register Access Timing ............................................................................................... 535 Hibernation Clock Source ............................................................................................ 535 System Implementation ............................................................................................... 538 Battery Management ................................................................................................... 539 Real-Time Clock .......................................................................................................... 539 Tamper ....................................................................................................................... 542 Battery-Backed Memory .............................................................................................. 545 Power Control Using HIB ............................................................................................. 545 Power Control Using VDD3ON Mode ........................................................................... 546 Initiating Hibernate ...................................................................................................... 546 Waking from Hibernate ................................................................................................ 546 Arbitrary Power Removal ............................................................................................. 547 Interrupts and Status ................................................................................................... 548 Initialization and Configuration ..................................................................................... 548 Initialization ................................................................................................................. 548 RTC Match Functionality (No Hibernation) .................................................................... 549 RTC Match/Wake-Up from Hibernation ......................................................................... 549 External Wake-Up from Hibernation .............................................................................. 550 RTC or External Wake-Up from Hibernation .................................................................. 551 Tamper Initialization ..................................................................................................... 551 Register Map .............................................................................................................. 551 Register Descriptions .................................................................................................. 553 8 Internal Memory ................................................................................................... 600 8.1 8.2 8.2.1 8.2.2 8.2.3 8.2.4 8.2.5 8.3 8.4 8.5 8.6 Block Diagram ............................................................................................................ 600 Functional Description ................................................................................................. 602 SRAM ........................................................................................................................ 602 ROM .......................................................................................................................... 602 Flash Memory ............................................................................................................. 604 EEPROM .................................................................................................................... 615 Bus Matrix Memory Accesses ...................................................................................... 621 Register Map .............................................................................................................. 621 Internal Memory Register Descriptions (Internal Memory Control Offset) ......................... 624 EEPROM Register Descriptions (EEPROM Offset) ........................................................ 650 Memory Register Descriptions (System Control Offset) .................................................. 667 June 18, 2014 5 Texas Instruments-Production Data Table of Contents 9 Micro Direct Memory Access (μDMA) ................................................................ 678 9.1 9.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.2.9 9.2.10 9.3 9.3.1 9.3.2 9.3.3 9.3.4 9.3.5 9.4 9.5 9.6 Block Diagram ............................................................................................................ 679 Functional Description ................................................................................................. 679 Channel Assignments .................................................................................................. 680 Priority ........................................................................................................................ 681 Arbitration Size ............................................................................................................ 682 Request Types ............................................................................................................ 682 Channel Configuration ................................................................................................. 683 Transfer Modes ........................................................................................................... 685 Transfer Size and Increment ........................................................................................ 693 Peripheral Interface ..................................................................................................... 693 Software Request ........................................................................................................ 694 Interrupts and Errors .................................................................................................... 694 Initialization and Configuration ..................................................................................... 694 Module Initialization ..................................................................................................... 694 Configuring a Memory-to-Memory Transfer ................................................................... 695 Configuring a Peripheral for Simple Transmit ................................................................ 696 Configuring a Peripheral for Ping-Pong Receive ............................................................ 698 Configuring Channel Assignments ................................................................................ 701 Register Map .............................................................................................................. 701 μDMA Channel Control Structure ................................................................................. 702 μDMA Register Descriptions ........................................................................................ 709 10 General-Purpose Input/Outputs (GPIOs) ........................................................... 742 10.1 10.2 10.3 10.3.1 10.3.2 10.3.3 10.3.4 10.3.5 10.3.6 10.4 10.5 10.6 Signal Description ....................................................................................................... 743 Pad Capabilities .......................................................................................................... 746 Functional Description ................................................................................................. 747 Data Control ............................................................................................................... 748 Interrupt Control .......................................................................................................... 750 Mode Control .............................................................................................................. 751 Commit Control ........................................................................................................... 752 Pad Control ................................................................................................................. 752 Identification ............................................................................................................... 753 Initialization and Configuration ..................................................................................... 753 Register Map .............................................................................................................. 755 Register Descriptions .................................................................................................. 758 11 External Peripheral Interface (EPI) ..................................................................... 815 11.1 11.2 11.3 11.3.1 11.3.2 11.3.3 11.4 11.4.1 11.4.2 11.4.3 11.4.4 11.5 EPI Block Diagram ...................................................................................................... Signal Description ....................................................................................................... Functional Description ................................................................................................. Master Access to EPI .................................................................................................. Non-Blocking Reads .................................................................................................... DMA Operation ........................................................................................................... Initialization and Configuration ..................................................................................... EPI Interface Options .................................................................................................. SDRAM Mode ............................................................................................................. Host Bus Mode ........................................................................................................... General-Purpose Mode ............................................................................................... Register Map .............................................................................................................. 6 816 817 818 819 819 820 821 822 822 826 847 854 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 11.6 Register Descriptions .................................................................................................. 856 12 Cyclical Redundancy Check (CRC) .................................................................... 946 12.1 12.1.1 12.2 12.2.1 12.3 12.4 Functional Description ................................................................................................. CRC Support .............................................................................................................. Initialization and Configuration ..................................................................................... CRC Initialization and Configuration ............................................................................. Register Map .............................................................................................................. CRC Module Register Descriptions .............................................................................. 946 946 948 948 949 949 13 General-Purpose Timers ...................................................................................... 955 13.1 13.2 13.3 13.3.1 13.3.2 13.3.3 13.3.4 13.3.5 13.3.6 13.3.7 13.3.8 13.4 13.4.1 13.4.2 13.4.3 13.4.4 13.4.5 13.5 13.6 Block Diagram ............................................................................................................ 956 Signal Description ....................................................................................................... 957 Functional Description ................................................................................................. 958 GPTM Reset Conditions .............................................................................................. 959 Timer Clock Source ..................................................................................................... 959 Timer Modes ............................................................................................................... 959 Wait-for-Trigger Mode .................................................................................................. 968 Synchronizing GP Timer Blocks ................................................................................... 969 DMA Operation ........................................................................................................... 970 ADC Operation ............................................................................................................ 970 Accessing Concatenated 16/32-Bit GPTM Register Values ............................................ 970 Initialization and Configuration ..................................................................................... 971 One-Shot/Periodic Timer Mode .................................................................................... 971 Real-Time Clock (RTC) Mode ...................................................................................... 972 Input Edge-Count Mode ............................................................................................... 972 Input Edge Time Mode ................................................................................................. 973 PWM Mode ................................................................................................................. 973 Register Map .............................................................................................................. 974 Register Descriptions .................................................................................................. 975 14 Watchdog Timers ............................................................................................... 1028 14.1 14.2 14.2.1 14.3 14.4 14.5 Block Diagram ........................................................................................................... Functional Description ............................................................................................... Register Access Timing ............................................................................................. Initialization and Configuration .................................................................................... Register Map ............................................................................................................ Register Descriptions ................................................................................................. 1029 1029 1030 1030 1030 1031 15 Analog-to-Digital Converter (ADC) ................................................................... 1053 15.1 15.2 15.3 15.3.1 15.3.2 15.3.3 15.3.4 15.3.5 15.3.6 15.3.7 15.4 Block Diagram ........................................................................................................... Signal Description ..................................................................................................... Functional Description ............................................................................................... Sample Sequencers .................................................................................................. Module Control .......................................................................................................... Hardware Sample Averaging Circuit ........................................................................... Analog-to-Digital Converter ........................................................................................ Differential Sampling .................................................................................................. Internal Temperature Sensor ...................................................................................... Digital Comparator Unit .............................................................................................. Initialization and Configuration .................................................................................... June 18, 2014 1054 1055 1056 1056 1057 1062 1063 1065 1067 1068 1072 7 Texas Instruments-Production Data Table of Contents 15.4.1 15.4.2 15.5 15.6 Module Initialization ................................................................................................... Sample Sequencer Configuration ............................................................................... Register Map ............................................................................................................ Register Descriptions ................................................................................................. 1072 1073 1073 1076 16 Universal Asynchronous Receivers/Transmitters (UARTs) ........................... 1161 16.1 Block Diagram ........................................................................................................... 1162 16.2 Signal Description ..................................................................................................... 1162 16.3 Functional Description ............................................................................................... 1164 16.3.1 Transmit/Receive Logic .............................................................................................. 1164 16.3.2 Baud-Rate Generation ............................................................................................... 1165 16.3.3 Data Transmission ..................................................................................................... 1166 16.3.4 Serial IR (SIR) ........................................................................................................... 1166 16.3.5 ISO 7816 Support ...................................................................................................... 1167 16.3.6 Modem Handshake Support ....................................................................................... 1168 16.3.7 9-Bit UART Mode ...................................................................................................... 1169 16.3.8 FIFO Operation ......................................................................................................... 1169 16.3.9 Interrupts .................................................................................................................. 1170 16.3.10 Loopback Operation .................................................................................................. 1171 16.3.11 DMA Operation ......................................................................................................... 1171 16.4 Initialization and Configuration .................................................................................... 1172 16.5 Register Map ............................................................................................................ 1173 16.6 Register Descriptions ................................................................................................. 1174 17 Quad Synchronous Serial Interface (QSSI) ..................................................... 1226 17.1 17.2 17.3 17.3.1 17.3.2 17.3.3 17.3.4 17.3.5 17.3.6 17.3.7 17.3.8 17.4 17.4.1 17.5 17.6 Block Diagram ........................................................................................................... 1226 Signal Description ..................................................................................................... 1227 Functional Description ............................................................................................... 1228 Bit Rate Generation ................................................................................................... 1229 FIFO Operation ......................................................................................................... 1229 Advanced, Bi- and Quad- SSI Function ....................................................................... 1230 SSInFSS Function ..................................................................................................... 1231 High Speed Clock Operation ...................................................................................... 1232 Interrupts .................................................................................................................. 1232 Frame Formats ......................................................................................................... 1233 DMA Operation ......................................................................................................... 1240 Initialization and Configuration .................................................................................... 1240 Enhanced Mode Configuration ................................................................................... 1242 Register Map ............................................................................................................ 1243 Register Descriptions ................................................................................................. 1244 18 Inter-Integrated Circuit (I2C) Interface .............................................................. 1275 18.1 18.2 18.3 18.3.1 18.3.2 18.3.3 18.3.4 18.3.5 18.3.6 Block Diagram ........................................................................................................... Signal Description ..................................................................................................... Functional Description ............................................................................................... I2C Bus Functional Overview ...................................................................................... Available Speed Modes ............................................................................................. Interrupts .................................................................................................................. Loopback Operation .................................................................................................. FIFO and µDMA Operation ........................................................................................ Command Sequence Flow Charts .............................................................................. 8 1276 1277 1278 1278 1284 1286 1287 1287 1289 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 18.4 18.4.1 18.4.2 18.5 18.6 18.7 18.8 Initialization and Configuration .................................................................................... Configure the I2C Module to Transmit a Single Byte as a Master .................................. Configure the I2C Master to High Speed Mode ............................................................ Register Map ............................................................................................................ Register Descriptions (I2C Master) .............................................................................. Register Descriptions (I2C Slave) ............................................................................... Register Descriptions (I2C Status and Control) ............................................................ 1297 1297 1298 1299 1301 1330 1347 19 Controller Area Network (CAN) Module ........................................................... 1356 19.1 Block Diagram ........................................................................................................... 1357 19.2 Signal Description ..................................................................................................... 1357 19.3 Functional Description ............................................................................................... 1358 19.3.1 Initialization ............................................................................................................... 1359 19.3.2 Operation .................................................................................................................. 1359 19.3.3 Transmitting Message Objects ................................................................................... 1360 19.3.4 Configuring a Transmit Message Object ...................................................................... 1361 19.3.5 Updating a Transmit Message Object ......................................................................... 1362 19.3.6 Accepting Received Message Objects ........................................................................ 1362 19.3.7 Receiving a Data Frame ............................................................................................ 1363 19.3.8 Receiving a Remote Frame ........................................................................................ 1363 19.3.9 Receive/Transmit Priority ........................................................................................... 1363 19.3.10 Configuring a Receive Message Object ...................................................................... 1364 19.3.11 Handling of Received Message Objects ...................................................................... 1365 19.3.12 Handling of Interrupts ................................................................................................ 1367 19.3.13 Test Mode ................................................................................................................. 1368 19.3.14 Bit Timing Configuration Error Considerations ............................................................. 1370 19.3.15 Bit Time and Bit Rate ................................................................................................. 1370 19.3.16 Calculating the Bit Timing Parameters ........................................................................ 1372 19.4 Register Map ............................................................................................................ 1375 19.5 CAN Register Descriptions ......................................................................................... 1376 20 Ethernet Controller ............................................................................................ 1407 20.1 Block Diagram ........................................................................................................... 1408 20.2 Signal Description ..................................................................................................... 1408 20.3 Functional Description ............................................................................................... 1409 20.3.1 Ethernet Clock Control ............................................................................................... 1409 20.3.2 DMA Controller ......................................................................................................... 1410 20.3.3 TX/RX Controller ....................................................................................................... 1434 20.3.4 MAC Operation ......................................................................................................... 1438 20.3.5 IEEE 1588 and Advanced Timestamp Function ........................................................... 1440 20.3.6 Frame Filtering .......................................................................................................... 1449 20.3.7 Source Address, VLAN, and CRC Insertion, Replacement or Deletion .......................... 1450 20.3.8 Checksum Offload Engine .......................................................................................... 1452 20.3.9 MAC Management Counters ...................................................................................... 1453 20.3.10 Power Management Module ....................................................................................... 1454 20.3.11 Serial Management Interface ..................................................................................... 1457 20.3.12 Interrupt Configuration ............................................................................................... 1457 20.4 Ethernet PHY ............................................................................................................ 1457 20.4.1 Integrated PHY Block Diagram ................................................................................... 1457 20.4.2 Functional Description ............................................................................................... 1458 June 18, 2014 9 Texas Instruments-Production Data Table of Contents 20.4.3 20.5 20.5.1 20.6 20.7 20.8 Interface Configuration ............................................................................................... Initialization and Configuration .................................................................................... Ethernet PHY Initialization .......................................................................................... Register Map ............................................................................................................ Ethernet MAC Register Descriptions ........................................................................... Ethernet PHY Register Descriptions ........................................................................... 1463 1464 1465 1467 1470 1589 21 Universal Serial Bus (USB) Controller ............................................................. 1644 21.1 21.2 21.3 Block Diagram ........................................................................................................... 1645 Signal Description ..................................................................................................... 1645 Register Map ............................................................................................................ 1646 22 Analog Comparators .......................................................................................... 1653 22.1 22.2 22.3 22.3.1 22.4 22.5 22.6 Block Diagram ........................................................................................................... Signal Description ..................................................................................................... Functional Description ............................................................................................... Internal Reference Programming ................................................................................ Initialization and Configuration .................................................................................... Register Map ............................................................................................................ Register Descriptions ................................................................................................. 1654 1654 1655 1656 1658 1659 1659 23 Pulse Width Modulator (PWM) .......................................................................... 1669 23.1 23.2 23.3 23.3.1 23.3.2 23.3.3 23.3.4 23.3.5 23.3.6 23.3.7 23.3.8 23.3.9 23.4 23.5 23.6 Block Diagram ........................................................................................................... 1670 Signal Description ..................................................................................................... 1672 Functional Description ............................................................................................... 1672 Clock Configuration ................................................................................................... 1672 PWM Timer ............................................................................................................... 1672 PWM Comparators .................................................................................................... 1673 PWM Signal Generator .............................................................................................. 1674 Dead-Band Generator ............................................................................................... 1675 Interrupt/ADC-Trigger Selector ................................................................................... 1675 Synchronization Methods .......................................................................................... 1676 Fault Conditions ........................................................................................................ 1677 Output Control Block .................................................................................................. 1678 Initialization and Configuration .................................................................................... 1678 Register Map ............................................................................................................ 1679 Register Descriptions ................................................................................................. 1682 24 Quadrature Encoder Interface (QEI) ................................................................. 1748 24.1 24.2 24.3 24.4 24.5 24.6 Block Diagram ........................................................................................................... Signal Description ..................................................................................................... Functional Description ............................................................................................... Initialization and Configuration .................................................................................... Register Map ............................................................................................................ Register Descriptions ................................................................................................. 25 Pin Diagram ........................................................................................................ 1771 1748 1750 1750 1753 1753 1754 26 Signal Tables ...................................................................................................... 1772 26.1 26.2 26.3 26.4 Signals by Pin Number .............................................................................................. Signals by Signal Name ............................................................................................. Signals by Function, Except for GPIO ......................................................................... GPIO Pins and Alternate Functions ............................................................................ 10 1773 1785 1797 1808 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 26.5 26.6 Possible Pin Assignments for Alternate Functions ....................................................... 1811 Connections for Unused Signals ................................................................................. 1816 27 Electrical Characteristics .................................................................................. 1818 27.1 Maximum Ratings ...................................................................................................... 1818 27.2 Operating Characteristics ........................................................................................... 1819 27.3 Recommended Operating Conditions ......................................................................... 1820 27.3.1 DC Operating Conditions ........................................................................................... 1820 27.3.2 Recommended GPIO Operating Characteristics .......................................................... 1820 27.4 Load Conditions ........................................................................................................ 1823 27.5 JTAG and Boundary Scan .......................................................................................... 1824 27.6 Power and Brown-Out ............................................................................................... 1826 27.6.1 VDDA Levels .............................................................................................................. 1826 27.6.2 VDD Levels ................................................................................................................ 1827 27.6.3 VDDC Levels .............................................................................................................. 1828 27.6.4 Response ................................................................................................................. 1829 27.7 Reset ........................................................................................................................ 1831 27.8 On-Chip Low Drop-Out (LDO) Regulator ..................................................................... 1834 27.9 Clocks ...................................................................................................................... 1835 27.9.1 PLL Specifications ..................................................................................................... 1835 27.9.2 PIOSC Specifications ................................................................................................ 1837 27.9.3 Low-Frequency Internal Oscillator Specifications ......................................................... 1837 27.9.4 Hibernation Clock Source Specifications ..................................................................... 1837 27.9.5 Main Oscillator Specifications ..................................................................................... 1838 27.9.6 System Clock Specification with ADC Operation .......................................................... 1842 27.9.7 System Clock Specification with USB Operation .......................................................... 1842 27.10 Sleep Modes ............................................................................................................. 1843 27.11 Hibernation Module ................................................................................................... 1845 27.12 Flash Memory ........................................................................................................... 1847 27.13 EEPROM .................................................................................................................. 1848 27.14 Input/Output Pin Characteristics ................................................................................. 1849 27.14.1 Types of I/O Pins and ESD Protection ......................................................................... 1851 27.15 External Peripheral Interface (EPI) .............................................................................. 1853 27.16 Analog-to-Digital Converter (ADC) .............................................................................. 1861 27.17 Synchronous Serial Interface (SSI) ............................................................................. 1867 27.18 Inter-Integrated Circuit (I2C) Interface ......................................................................... 1870 27.19 Ethernet Controller .................................................................................................... 1871 27.19.1 DC Characteristics .................................................................................................... 1871 27.19.2 Clock Characteristics ................................................................................................. 1871 27.19.3 AC Characteristics ..................................................................................................... 1872 27.20 Universal Serial Bus (USB) Controller ......................................................................... 1875 27.21 Analog Comparator ................................................................................................... 1877 27.22 Pulse-Width Modulator (PWM) ................................................................................... 1879 27.23 Current Consumption ................................................................................................ 1880 A Package Information .......................................................................................... 1885 A.1 A.2 A.3 A.4 Orderable Devices ..................................................................................................... Device Nomenclature ................................................................................................ Device Markings ........................................................................................................ Packaging Diagram ................................................................................................... June 18, 2014 1885 1885 1885 1887 11 Texas Instruments-Production Data Table of Contents List of Figures Figure 1-1. Figure 2-1. Figure 2-2. Figure 2-3. Figure 2-4. Figure 2-5. Figure 2-6. Figure 2-7. Figure 3-1. Figure 3-2. Figure 4-1. Figure 4-2. Figure 4-3. Figure 4-4. Figure 4-5. Figure 5-1. Figure 5-2. Figure 5-3. Figure 5-4. Figure 5-5. Figure 5-6. Figure 7-1. Figure 7-2. Figure 7-3. Figure 7-4. Figure 7-5. Figure 7-6. Figure 7-7. Figure 7-8. Figure 8-1. Figure 8-2. Figure 8-3. Figure 8-4. Figure 8-5. Figure 8-6. Figure 8-7. Figure 9-1. Figure 9-2. Figure 9-3. Figure 9-4. Figure 9-5. Figure 9-6. Figure 10-1. Figure 10-2. Figure 10-3. Tiva™ TM4C1294NCPDT Microcontroller High-Level Block Diagram ....................... 54 CPU Block Diagram ............................................................................................. 82 TPIU Block Diagram ............................................................................................ 83 Cortex-M4F Register Set ...................................................................................... 86 Bit-Band Mapping .............................................................................................. 111 Data Storage ..................................................................................................... 112 Vector Table ...................................................................................................... 119 Exception Stack Frame ...................................................................................... 122 SRD Use Example ............................................................................................. 140 FPU Register Bank ............................................................................................ 143 JTAG Module Block Diagram .............................................................................. 208 Test Access Port State Machine ......................................................................... 212 IDCODE Register Format ................................................................................... 218 BYPASS Register Format ................................................................................... 218 Boundary Scan Register Format ......................................................................... 218 Basic RST Configuration .................................................................................... 224 External Circuitry to Extend Power-On Reset ....................................................... 224 Reset Circuit Controlled by Switch ...................................................................... 224 Power Architecture ............................................................................................ 229 Main Clock Tree ................................................................................................ 233 Module Clock Selection ...................................................................................... 242 Hibernation Module Block Diagram ..................................................................... 533 Using a Crystal as the Hibernation Clock Source with a Single Battery Source ...... 537 Using a Dedicated Oscillator as the Hibernation Clock Source with VDD3ON Mode ................................................................................................................ 537 Using a Regulator for Both VDD and VBAT ............................................................ 538 Counter Behavior with a TRIM Value of 0x8002 ................................................... 542 Counter Behavior with a TRIM Value of 0x7FFC .................................................. 542 Tamper Block Diagram ....................................................................................... 542 Tamper Pad with Glitch Filtering ......................................................................... 543 Internal Memory Block Diagram .......................................................................... 601 Flash Memory Configuration ............................................................................... 605 Single 256-Bit Prefetch Buffer Set ....................................................................... 606 Four 256-Bit Prefetch Buffer Configuration .......................................................... 606 Single Cycle Access, 0 Wait States ..................................................................... 607 Prefetch Fills from Flash ..................................................................................... 608 Mirror Mode Function ......................................................................................... 609 μDMA Block Diagram ......................................................................................... 679 Example of Ping-Pong μDMA Transaction ........................................................... 686 Memory Scatter-Gather, Setup and Configuration ................................................ 688 Memory Scatter-Gather, μDMA Copy Sequence .................................................. 689 Peripheral Scatter-Gather, Setup and Configuration ............................................. 691 Peripheral Scatter-Gather, μDMA Copy Sequence ............................................... 692 Digital I/O Pads ................................................................................................. 747 Analog/Digital I/O Pads ...................................................................................... 748 GPIODATA Write Example ................................................................................. 749 12 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 10-4. Figure 11-1. Figure 11-2. Figure 11-3. Figure 11-4. Figure 11-5. Figure 11-6. Figure 11-7. Figure 11-8. Figure 11-9. Figure 11-10. Figure 11-11. Figure 11-12. Figure 11-13. Figure 11-14. Figure 11-15. Figure 11-16. Figure 11-17. Figure 11-18. Figure 11-19. Figure 11-20. Figure 11-21. Figure 11-22. Figure 11-23. Figure 11-24. Figure 11-25. Figure 11-26. Figure 11-27. Figure 11-28. Figure 11-29. Figure 13-1. Figure 13-2. Figure 13-3. Figure 13-4. Figure 13-5. Figure 13-6. Figure 13-7. Figure 13-8. Figure 14-1. Figure 15-1. Figure 15-2. Figure 15-3. Figure 15-4. Figure 15-5. Figure 15-6. Figure 15-7. GPIODATA Read Example ................................................................................. 749 EPI Block Diagram ............................................................................................. 817 SDRAM Non-Blocking Read Cycle ...................................................................... 824 SDRAM Normal Read Cycle ............................................................................... 825 SDRAM Write Cycle ........................................................................................... 826 iRDY Access Stalls, IRDYDLY==01, 10, 11 .......................................................... 836 iRDY Signal Connection ..................................................................................... 836 PSRAM Burst Read ........................................................................................... 839 PSRAM Burst Write ........................................................................................... 839 Read Delay During Refresh Event ...................................................................... 840 Write Delay During Refresh Event ....................................................................... 841 Example Schematic for Muxed Host-Bus 16 Mode ............................................... 842 Host-Bus Read Cycle, MODE = 0x1, WRHIGH = 0, RDHIGH = 0 .......................... 845 Host-Bus Write Cycle, MODE = 0x1, WRHIGH = 0, RDHIGH = 0 .......................... 845 Host-Bus Write Cycle with Multiplexed Address and Data, MODE = 0x0, WRHIGH = 0, RDHIGH = 0 ............................................................................................... 846 Host-Bus Write Cycle with Multiplexed Address and Data and ALE with Dual or Quad CSn ......................................................................................................... 846 Continuous Read Mode Accesses ...................................................................... 846 Write Followed by Read to External FIFO ............................................................ 847 Two-Entry FIFO ................................................................................................. 847 Single-Cycle Single Write Access, FRM50=0, FRMCNT=0, WR2CYC=0 ............... 850 Two-Cycle Read, Write Accesses, FRM50=0, FRMCNT=0, WR2CYC=1 ............... 851 Read Accesses, FRM50=0, FRMCNT=0 ............................................................. 851 FRAME Signal Operation, FRM50=0 and FRMCNT=0 ......................................... 852 FRAME Signal Operation, FRM50=0 and FRMCNT=1 ......................................... 852 FRAME Signal Operation, FRM50=0 and FRMCNT=2 ......................................... 852 FRAME Signal Operation, FRM50=1 and FRMCNT=0 ......................................... 852 FRAME Signal Operation, FRM50=1 and FRMCNT=1 ......................................... 853 FRAME Signal Operation, FRM50=1 and FRMCNT=2 ......................................... 853 EPI Clock Operation, CLKGATE=1, WR2CYC=0 ................................................. 853 EPI Clock Operation, CLKGATE=1, WR2CYC=1 ................................................. 854 GPTM Module Block Diagram ............................................................................ 956 Input Edge-Count Mode Example, Counting Down ............................................... 964 16-Bit Input Edge-Time Mode Example ............................................................... 965 16-Bit PWM Mode Example ................................................................................ 967 CCP Output, GPTMTnMATCHR > GPTMTnILR ................................................... 967 CCP Output, GPTMTnMATCHR = GPTMTnILR ................................................... 968 CCP Output, GPTMTnILR > GPTMTnMATCHR ................................................... 968 Timer Daisy Chain ............................................................................................. 969 WDT Module Block Diagram ............................................................................. 1029 Implementation of Two ADC Blocks .................................................................. 1054 ADC Module Block Diagram ............................................................................. 1055 ADC Sample Phases ....................................................................................... 1060 Doubling the ADC Sample Rate ........................................................................ 1060 Skewed Sampling ............................................................................................ 1061 Sample Averaging Example .............................................................................. 1063 ADC Input Equivalency .................................................................................... 1064 June 18, 2014 13 Texas Instruments-Production Data Table of Contents Figure 15-8. Figure 15-9. Figure 15-10. Figure 15-11. Figure 15-12. Figure 15-13. Figure 15-14. Figure 16-1. Figure 16-2. Figure 16-3. Figure 17-1. Figure 17-2. Figure 17-3. Figure 17-4. Figure 17-5. Figure 17-6. Figure 17-7. Figure 17-8. Figure 17-9. Figure 18-1. Figure 18-2. Figure 18-3. Figure 18-4. Figure 18-5. Figure 18-6. Figure 18-7. Figure 18-8. Figure 18-9. Figure 18-10. Figure 18-11. Figure 18-12. Figure 18-13. Figure 18-14. Figure 18-15. Figure 19-1. Figure 19-2. Figure 19-3. Figure 19-4. Figure 20-1. Figure 20-2. Figure 20-3. Figure 20-4. Figure 20-5. Figure 20-6. Figure 20-7. Figure 20-8. Figure 20-9. ADC Voltage Reference ................................................................................... 1064 ADC Conversion Result ................................................................................... 1065 Differential Voltage Representation ................................................................... 1067 Internal Temperature Sensor Characteristic ....................................................... 1068 Low-Band Operation (CIC=0x0 and/or CTC=0x0) .............................................. 1070 Mid-Band Operation (CIC=0x1 and/or CTC=0x1) ............................................... 1071 High-Band Operation (CIC=0x3 and/or CTC=0x3) .............................................. 1072 UART Module Block Diagram ........................................................................... 1162 UART Character Frame .................................................................................... 1165 IrDA Data Modulation ....................................................................................... 1167 QSSI Module with Advanced, Bi-SSI and Quad-SSI Support .............................. 1227 TI Synchronous Serial Frame Format (Single Transfer) ...................................... 1234 TI Synchronous Serial Frame Format (Continuous Transfer) ............................... 1235 Freescale SPI Format (Single Transfer) with SPO=0 and SPH=0 ........................ 1236 Freescale SPI Format (Continuous Transfer) with SPO=0 and SPH=0 ................ 1236 Freescale SPI Frame Format with SPO=0 and SPH=1 ....................................... 1237 Freescale SPI Frame Format (Single Transfer) with SPO=1 and SPH=0 ............. 1238 Freescale SPI Frame Format (Continuous Transfer) with SPO=1 and SPH=0 ...... 1238 Freescale SPI Frame Format with SPO=1 and SPH=1 ....................................... 1239 I2C Block Diagram ........................................................................................... 1276 I2C Bus Configuration ....................................................................................... 1278 START and STOP Conditions ........................................................................... 1279 Complete Data Transfer with a 7-Bit Address ..................................................... 1279 R/S Bit in First Byte .......................................................................................... 1280 Data Validity During Bit Transfer on the I2C Bus ................................................. 1280 High-Speed Data Format .................................................................................. 1286 Master Single TRANSMIT ................................................................................ 1290 Master Single RECEIVE ................................................................................... 1291 Master TRANSMIT of Multiple Data Bytes ......................................................... 1292 Master RECEIVE of Multiple Data Bytes ............................................................ 1293 Master RECEIVE with Repeated START after Master TRANSMIT ....................... 1294 Master TRANSMIT with Repeated START after Master RECEIVE ....................... 1295 Standard High Speed Mode Master Transmit ..................................................... 1296 Slave Command Sequence .............................................................................. 1297 CAN Controller Block Diagram .......................................................................... 1357 CAN Data/Remote Frame ................................................................................. 1358 Message Objects in a FIFO Buffer .................................................................... 1367 CAN Bit Time ................................................................................................... 1371 Ethernet MAC with Integrated PHY Interface ..................................................... 1408 Ethernet MAC and PHY Clock Structure ............................................................ 1410 Enhanced Transmit Descriptor Structure ........................................................... 1414 Enhanced Receive Descriptor Structure ............................................................ 1419 TX DMA Default Operation Using Descriptors .................................................... 1426 TX DMA OSF Mode Operation Using Descriptors .............................................. 1428 RX DMA Operation Flow .................................................................................. 1431 Networked Time Synchronization ...................................................................... 1441 System Time Update Using Fine Correction Method .......................................... 1443 14 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 20-10. Propagation Delay Calculation in Clocks Supporting Peer-to-Peer Path Correction ....................................................................................................... 1446 Figure 20-11. Wake-Up Frame Filter Register Bank ................................................................ 1454 Figure 20-12. Integrated PHY Diagram .................................................................................. 1458 Figure 20-13. Interface to Ethernet Jack ................................................................................. 1464 Figure 21-1. USB Module Block Diagram ............................................................................. 1645 Figure 22-1. Analog Comparator Module Block Diagram ....................................................... 1654 Figure 22-2. Structure of Comparator Unit ............................................................................ 1655 Figure 22-3. Comparator Internal Reference Structure .......................................................... 1656 Figure 23-1. PWM Module Diagram ..................................................................................... 1671 Figure 23-2. PWM Generator Block Diagram ........................................................................ 1671 Figure 23-3. PWM Count-Down Mode .................................................................................. 1674 Figure 23-4. PWM Count-Up/Down Mode ............................................................................. 1674 Figure 23-5. PWM Generation Example In Count-Up/Down Mode .......................................... 1675 Figure 23-6. PWM Dead-Band Generator ............................................................................. 1675 Figure 24-1. QEI Block Diagram .......................................................................................... 1749 Figure 24-2. QEI Input Signal Logic ...................................................................................... 1750 Figure 24-3. Quadrature Encoder and Velocity Predivider Operation ...................................... 1752 Figure 25-1. 128-Pin TQFP Package Pin Diagram ................................................................ 1771 Figure 27-1. Load Conditions ............................................................................................... 1823 Figure 27-2. JTAG Test Clock Input Timing ........................................................................... 1825 Figure 27-3. JTAG Test Access Port (TAP) Timing ................................................................ 1825 Figure 27-4. Power and Brown-Out Assertions vs VDDA Levels .............................................. 1827 Figure 27-5. Power and Brown-Out Assertions vs VDD Levels ................................................ 1828 Figure 27-6. POK Assertion vs VDDC ................................................................................... 1829 Figure 27-7. POR-BOR VDD Glitch Response ....................................................................... 1829 Figure 27-8. POR-BOR VDD Droop Response ...................................................................... 1830 Figure 27-9. Digital Power-On Reset Timing ......................................................................... 1831 Figure 27-10. Brown-Out Reset Timing .................................................................................. 1832 Figure 27-11. External Reset Timing (RST) ............................................................................ 1832 Figure 27-12. Software Reset Timing ..................................................................................... 1832 Figure 27-13. Watchdog Reset Timing ................................................................................... 1832 Figure 27-14. MOSC Failure Reset Timing ............................................................................. 1833 Figure 27-15. Hibernation Module Timing ............................................................................... 1846 Figure 27-16. ESD Protection ................................................................................................ 1851 Figure 27-17. ESD Protection for Non-Power Pins (Except WAKE Signal) ................................ 1852 Figure 27-18. SDRAM Initialization and Load Mode Register Timing ........................................ 1854 Figure 27-19. SDRAM Read Timing ....................................................................................... 1854 Figure 27-20. SDRAM Write Timing ....................................................................................... 1855 Figure 27-21. Host-Bus 8/16 Asynchronous Mode Read Timing ............................................... 1856 Figure 27-22. Host-Bus 8/16 Asynchronous Mode Write Timing ............................................... 1856 Figure 27-23. Host-Bus 8/16 Mode Asynchronous Muxed Read Timing .................................... 1857 Figure 27-24. Host-Bus 8/16 Mode Asynchronous Muxed Write Timing .................................... 1857 Figure 27-25. General-Purpose Mode Read and Write Timing ................................................. 1858 Figure 27-26. PSRAM Single Burst Read ............................................................................... 1859 Figure 27-27. PSRAM Single Burst Write ............................................................................... 1860 Figure 27-28. ADC External Reference Filtering ..................................................................... 1866 Figure 27-29. ADC Input Equivalency .................................................................................... 1866 June 18, 2014 15 Texas Instruments-Production Data Table of Contents Figure 27-30. SSI Timing for TI Frame Format (FRF=01), Single Transfer Timing Measurement .................................................................................................. 1868 Figure 27-31. Master Mode SSI Timing for SPI Frame Format (FRF=00), with SPH=1 .............. 1868 Figure 27-32. Slave Mode SSI Timing for SPI Frame Format (FRF=00), with SPH=1 ................ 1869 Figure 27-33. I2C Timing ....................................................................................................... 1870 Figure 27-34. MOSC Crystal Characteristics for Ethernet ........................................................ 1871 Figure 27-35. Single-Ended MOSC Characteristics for Ethernet .............................................. 1872 Figure 27-36. Reset Timing ................................................................................................... 1872 Figure 27-37. 100 Base-TX Transmit Timing ........................................................................... 1873 Figure 27-38. 10Base-TX Normal Link Pulse Timing ............................................................... 1873 Figure 27-39. Auto-Negotiation Fast Link Pulse Timing ........................................................... 1874 Figure 27-40. 100Base-TX Signal Detect Timing ..................................................................... 1874 Figure 27-41. ULPI Interface Timing Diagram ......................................................................... 1876 Figure A-1. Key to Part Numbers ........................................................................................ 1885 Figure A-2. TM4C1294NCPDT 128-Pin TQFP Package Diagram ......................................... 1887 16 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller List of Tables Table 1. Table 2. Table 1-1. Table 2-1. Table 2-2. Table 2-3. Table 2-4. Table 2-5. Table 2-6. Table 2-7. Table 2-8. Table 2-9. Table 2-10. Table 2-11. Table 2-12. Table 2-13. Table 3-1. Table 3-2. Table 3-3. Table 3-4. Table 3-5. Table 3-6. Table 3-7. Table 3-8. Table 3-9. Table 3-10. Table 4-1. Table 4-2. Table 4-3. Table 5-1. Table 5-2. Table 5-3. Table 5-4. Table 5-5. Table 5-6. Table 5-7. Table 5-8. Table 5-9. Table 5-10. Table 5-11. Table 5-12. Table 5-13. Table 5-14. Table 5-15. Table 5-16. Table 5-17. Revision History .................................................................................................. 45 Documentation Conventions ................................................................................ 49 TM4C1294NCPDT Microcontroller Features .......................................................... 52 Summary of Processor Mode, Privilege Level, and Stack Use ................................ 85 Processor Register Map ....................................................................................... 86 PSR Register Combinations ................................................................................. 92 Memory Map ..................................................................................................... 103 Memory Access Behavior ................................................................................... 107 SRAM Memory Bit-Banding Regions ................................................................... 109 Peripheral Memory Bit-Banding Regions ............................................................. 109 Exception Types ................................................................................................ 115 Interrupts .......................................................................................................... 116 Exception Return Behavior ................................................................................. 123 Faults ............................................................................................................... 124 Fault Status and Fault Address Registers ............................................................ 125 Cortex-M4F Instruction Summary ....................................................................... 127 Core Peripheral Register Regions ....................................................................... 134 Memory Attributes Summary .............................................................................. 138 TEX, S, C, and B Bit Field Encoding ................................................................... 140 Cache Policy for Memory Attribute Encoding ....................................................... 141 AP Bit Field Encoding ........................................................................................ 141 Memory Region Attributes for Tiva™ C Series Microcontrollers ............................. 142 QNaN and SNaN Handling ................................................................................. 145 Peripherals Register Map ................................................................................... 146 Interrupt Priority Levels ...................................................................................... 171 Example SIZE Field Values ................................................................................ 199 JTAG_SWD_SWO Signals (128TQFP) ............................................................... 208 JTAG Port Pins State after Power-On Reset or RST assertion .............................. 210 JTAG Instruction Register Commands ................................................................. 216 System Control & Clocks Signals (128TQFP) ...................................................... 220 Reset Sources ................................................................................................... 221 Clock Source Options ........................................................................................ 231 Clock Source State Following POR ..................................................................... 231 System Clock Frequency ................................................................................... 235 System Divisor Factors for fvco=480 MHz ............................................................ 237 Actual PLL Frequency ........................................................................................ 238 Peripheral Memory Power Control ...................................................................... 243 Maximum System Clock and PIOSC Frequency with Respect to LDO Voltage ....... 244 MOSC Configurations ........................................................................................ 247 System Control Register Map ............................................................................. 247 MEMTIM0 Register Configuration versus Frequency ............................................ 277 MOSC Configurations ........................................................................................ 281 Maximum System Clock and PIOSC Frequency with Respect to LDO Voltage ....... 300 Maximum System Clock and PIOSC Frequency with Respect to LDO Voltage ....... 303 Module Power Control ........................................................................................ 451 Module Power Control ........................................................................................ 453 June 18, 2014 17 Texas Instruments-Production Data Table of Contents Table 5-18. Table 5-19. Table 5-20. Table 5-21. Table 5-22. Table 5-23. Table 5-24. Table 5-25. Table 5-26. Table 5-27. Table 5-28. Table 5-29. Table 5-30. Table 5-31. Table 5-32. Table 5-33. Table 5-34. Table 6-1. Table 7-1. Table 7-2. Table 7-3. Table 8-1. Table 8-2. Table 8-3. Table 8-4. Table 8-5. Table 8-6. Table 9-1. Table 9-2. Table 9-3. Table 9-4. Table 9-5. Table 9-6. Table 9-7. Table 9-8. Table 9-9. Table 9-10. Table 9-11. Table 9-12. Table 9-13. Table 10-1. Table 10-2. Table 10-3. Table 10-4. Table 10-5. Table 10-6. Table 10-7. Module Power Control ........................................................................................ 456 Module Power Control ........................................................................................ 461 Module Power Control ........................................................................................ 463 Module Power Control ........................................................................................ 465 Module Power Control ........................................................................................ 467 Module Power Control ........................................................................................ 470 Module Power Control ........................................................................................ 472 Module Power Control ........................................................................................ 476 Module Power Control ........................................................................................ 478 Module Power Control ........................................................................................ 480 Module Power Control ........................................................................................ 482 Module Power Control ........................................................................................ 484 Module Power Control ........................................................................................ 486 Module Power Control ........................................................................................ 488 Module Power Control ........................................................................................ 490 Module Power Control ........................................................................................ 492 Module Power Control ........................................................................................ 494 System Exception Register Map ......................................................................... 523 Hibernate Signals (128TQFP) ............................................................................. 534 HIB Clock Source Configurations ........................................................................ 535 Hibernation Module Register Map ....................................................................... 552 MEMTIM0 Register Configuration versus Frequency ............................................ 605 Flash Memory Protection Policy Combinations .................................................... 610 User-Programmable Flash Memory Resident Registers ....................................... 614 MEMTIM0 Register Configuration versus Frequency ............................................ 617 Master Memory Access Availability ..................................................................... 621 Flash Register Map ............................................................................................ 622 μDMA Channel Assignments .............................................................................. 680 Request Type Support ....................................................................................... 682 Control Structure Memory Map ........................................................................... 684 Channel Control Structure .................................................................................. 684 μDMA Read Example: 8-Bit Peripheral ................................................................ 693 μDMA Interrupt Assignments .............................................................................. 694 Channel Control Structure Offsets for Channel 30 ................................................ 695 Channel Control Word Configuration for Memory Transfer Example ...................... 696 Channel Control Structure Offsets for Channel 7 .................................................. 697 Channel Control Word Configuration for Peripheral Transmit Example .................. 697 Primary and Alternate Channel Control Structure Offsets for Channel 8 ................. 699 Channel Control Word Configuration for Peripheral Ping-Pong Receive Example ............................................................................................................ 699 μDMA Register Map .......................................................................................... 701 GPIO Pins With Special Considerations .............................................................. 743 GPIO Pins and Alternate Functions (128TQFP) ................................................... 743 GPIO Drive Strength Options .............................................................................. 753 GPIO Pad Configuration Examples ..................................................................... 754 GPIO Interrupt Configuration Example ................................................................ 755 GPIO Pins With Special Considerations .............................................................. 756 GPIO Register Map ........................................................................................... 757 18 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 10-8. Table 10-9. Table 10-10. Table 10-11. Table 10-12. Table 10-13. Table 11-1. Table 11-2. Table 11-3. Table 11-4. Table 11-5. Table 11-6. Table 11-7. Table 11-8. Table 11-9. Table 11-10. Table 11-11. Table 11-12. Table 11-13. Table 11-14. Table 11-15. Table 12-1. Table 12-2. Table 12-3. Table 13-1. Table 13-2. Table 13-3. Table 13-4. Table 13-5. Table 13-6. Table 13-7. Table 13-8. Table 13-9. Table 13-10. Table 13-11. Table 14-1. Table 15-1. Table 15-2. Table 15-3. Table 15-4. Table 15-5. Table 15-6. Table 15-7. Table 15-8. Table 15-9. Table 15-10. Table 16-1. Table 16-2. GPIO Pins With Special Considerations .............................................................. 770 GPIO Pins With Special Considerations .............................................................. 776 GPIO Pins With Special Considerations .............................................................. 778 GPIO Pins With Special Considerations .............................................................. 781 GPIO Pins With Special Considerations .............................................................. 787 GPIO Drive Strength Options .............................................................................. 800 External Peripheral Interface Signals (128TQFP) ................................................. 817 EPI Interface Options ......................................................................................... 822 EPI SDRAM x16 Signal Connections .................................................................. 823 CSCFGEXT + CSCFG Encodings ...................................................................... 827 Dual- and Quad- Chip Select Address Mappings ................................................. 828 Chip Select Configuration Register Assignment ................................................... 829 Capabilities of Host Bus 8 and Host Bus 16 Modes .............................................. 829 EPI Host-Bus 8 Signal Connections .................................................................... 831 EPI Host-Bus 16 Signal Connections .................................................................. 833 PSRAM Fixed Latency Wait State Configuration .................................................. 838 Data Phase Wait State Programming .................................................................. 843 EPI General-Purpose Signal Connections ........................................................... 849 External Peripheral Interface (EPI) Register Map ................................................. 854 CSCFGEXT + CSCFG Encodings ...................................................................... 880 CSCFGEXT + CSCFG Encodings ...................................................................... 886 Endian Configuration ......................................................................................... 947 Endian Configuration with Bit Reversal ................................................................ 947 CCM Register Map ............................................................................................ 949 Available CCP Pins ............................................................................................ 956 General-Purpose Timers Signals (128TQFP) ....................................................... 957 General-Purpose Timer Capabilities .................................................................... 958 Counter Values When the Timer is Enabled in Periodic or One-Shot Modes .......... 960 16-Bit Timer With Prescaler Configurations ......................................................... 961 Counter Values When the Timer is Enabled in RTC Mode .................................... 962 Counter Values When the Timer is Enabled in Input Edge-Count Mode ................. 963 Counter Values When the Timer is Enabled in Input Event-Count Mode ................ 964 Counter Values When the Timer is Enabled in PWM Mode ................................... 966 Timeout Actions for GPTM Modes ...................................................................... 969 Timers Register Map .......................................................................................... 974 Watchdog Timers Register Map ........................................................................ 1031 ADC Signals (128TQFP) .................................................................................. 1055 Samples and FIFO Depth of Sequencers .......................................................... 1056 Sample and Hold Width in ADC Clocks ............................................................. 1058 RS and FCONV Values with Varying NSH Values and FADC = 16 MHz ..................... 1059 RS and FCONV Values with Varying NSH Values and FADC = 32 MHz ..................... 1059 Differential Sampling Pairs ............................................................................... 1066 ADC Register Map ........................................................................................... 1073 Sample and Hold Width in ADC Clocks ............................................................. 1127 Sample and Hold Width in ADC Clocks ............................................................. 1139 Sample and Hold Width in ADC Clocks ............................................................. 1147 UART Signals (128TQFP) ................................................................................ 1163 Flow Control Mode ........................................................................................... 1169 June 18, 2014 19 Texas Instruments-Production Data Table of Contents Table 16-3. Table 17-1. Table 17-2. Table 17-3. Table 17-4. Table 17-5. Table 18-1. Table 18-2. Table 18-3. Table 18-4. Table 18-5. Table 19-1. Table 19-2. Table 19-3. Table 19-4. Table 19-5. Table 20-1. Table 20-2. Table 20-3. Table 20-4. Table 20-5. Table 20-6. Table 20-7. Table 20-8. Table 20-9. Table 20-10. Table 20-11. Table 20-12. Table 20-13. Table 20-14. Table 20-15. Table 20-16. Table 20-17. Table 20-18. Table 20-19. Table 20-20. Table 20-21. Table 20-22. Table 20-23. Table 20-24. Table 21-1. Table 21-2. Table 22-1. Table 22-2. Table 22-3. Table 22-4. UART Register Map ......................................................................................... 1173 SSI Signals (128TQFP) .................................................................................... 1228 QSSI Transaction Encodings ............................................................................ 1231 SSInFss Functionality ...................................................................................... 1231 Legacy Mode TI, Freescale SPI Frame Format Features .................................... 1233 SSI Register Map ............................................................................................. 1243 I2C Signals (128TQFP) .................................................................................... 1277 Examples of I2C Master Timer Period Versus Speed Mode ................................. 1284 Examples of I2C Master Timer Period in High-Speed Mode ................................ 1285 Inter-Integrated Circuit (I2C) Interface Register Map ........................................... 1300 Write Field Decoding for I2CMCS[6:0] ............................................................... 1308 Controller Area Network Signals (128TQFP) ...................................................... 1357 Message Object Configurations ........................................................................ 1363 CAN Protocol Ranges ...................................................................................... 1371 CANBIT Register Values .................................................................................. 1371 CAN Register Map ........................................................................................... 1375 Ethernet Signals (128TQFP) ............................................................................. 1409 Enhanced Transmit Descriptor 0 (TDES0) ......................................................... 1414 Enhanced Transmit Descriptor 1 (TDES1) ......................................................... 1417 Enhanced Transmit Descriptor 2 (TDES2) ......................................................... 1418 Enhanced Transmit Descriptor 3 (TDES3) ......................................................... 1418 Enhanced Transmit Descriptor 6 (TDES6) ......................................................... 1418 Enhanced Transmit Descriptor 7 (TDES7) ......................................................... 1418 Enhanced Receive Descriptor 0 (RDES0) .......................................................... 1419 RDES0 Checksum Offload bits ......................................................................... 1421 Enhanced Receive Descriptor 1 (RDES1) .......................................................... 1422 Enhanced Receive Descriptor 2 (RDES2) .......................................................... 1422 Enhanced Receive Descriptor 3 (RDES3) .......................................................... 1422 Enhanced Received Descriptor 4 (RDES4) ........................................................ 1422 Enhanced Receive Descriptor 6 (RDES6) .......................................................... 1424 Enhanced Receive Descriptor 7 (RDES7) .......................................................... 1424 TX MAC Flow Control ...................................................................................... 1437 RX MAC Flow Control ...................................................................................... 1437 VLAN Match Status .......................................................................................... 1450 CRC Replacement Based on Bit 27 and Bit 24 of TDES0 ................................... 1452 Forced Mode Configurations ............................................................................. 1458 Advertised Mode Configurations ....................................................................... 1459 EMACPC to PHY Register Mapping .................................................................. 1465 Ethernet Register Map ..................................................................................... 1467 PPSCTRL Bit Field Values ............................................................................... 1549 USB Signals (128TQFP) .................................................................................. 1646 List of Registers ............................................................................................... 1647 Analog Comparators Signals (128TQFP) ........................................................... 1654 Internal Reference Voltage and ACREFCTL Field Values ................................... 1656 Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 0 .......................................................................................................... 1657 Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 1 .......................................................................................................... 1658 20 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 22-5. Table 23-1. Table 23-2. Table 24-1. Table 24-2. Table 26-1. Table 26-2. Table 26-3. Table 26-4. Table 26-5. Table 26-6. Table 26-7. Table 27-1. Table 27-2. Table 27-3. Table 27-4. Table 27-5. Table 27-6. Table 27-7. Table 27-8. Table 27-9. Table 27-10. Table 27-11. Table 27-12. Table 27-13. Table 27-14. Table 27-15. Table 27-16. Table 27-17. Table 27-18. Table 27-19. Table 27-20. Table 27-21. Table 27-22. Table 27-23. Table 27-24. Table 27-25. Table 27-26. Table 27-27. Table 27-28. Table 27-29. Table 27-30. Table 27-31. Table 27-32. Table 27-33. Table 27-34. Table 27-35. Table 27-36. Analog Comparators Register Map ................................................................... 1659 PWM Signals (128TQFP) ................................................................................. 1672 PWM Register Map .......................................................................................... 1679 QEI Signals (128TQFP) ................................................................................... 1750 QEI Register Map ............................................................................................ 1754 GPIO Pins With Special Considerations ............................................................ 1772 Signals by Pin Number ..................................................................................... 1773 Signals by Signal Name ................................................................................... 1785 Signals by Function, Except for GPIO ............................................................... 1797 GPIO Pins and Alternate Functions ................................................................... 1808 Possible Pin Assignments for Alternate Functions .............................................. 1811 Connections for Unused Signals (128-Pin TQFP) ............................................... 1816 Absolute Maximum Ratings .............................................................................. 1818 ESD Absolute Maximum Ratings ...................................................................... 1818 Temperature Characteristics ............................................................................. 1819 128-pin TQFP Power Dissipation ...................................................................... 1819 Thermal Characteristics ................................................................................... 1819 Recommended DC Operating Conditions .......................................................... 1820 Recommended FAST GPIO Pad Operating Conditions ...................................... 1820 Recommended Slow GPIO Pad Operating Conditions ........................................ 1821 GPIO Current Restrictions ................................................................................ 1821 Maximum GPIO Package Side Assignments ..................................................... 1822 Load Conditions ............................................................................................... 1823 JTAG Characteristics ....................................................................................... 1824 Power and Brown-Out Levels ........................................................................... 1826 Reset Characteristics ....................................................................................... 1831 LDO Regulator Characteristics ......................................................................... 1834 Phase Locked Loop (PLL) Characteristics ......................................................... 1835 System Divisor Factors for fvco=480 MHz ........................................................... 1836 Actual PLL Frequency ...................................................................................... 1836 PIOSC Clock Characteristics ............................................................................ 1837 Low-Frequency Oscillator Characteristics .......................................................... 1837 Hibernation Internal Low Frequency Oscillator Clock Characteristics ................... 1837 Hibernation External Oscillator (XOSC) Input Characteristics .............................. 1837 Main Oscillator Input Characteristics ................................................................. 1838 Crystal Parameters .......................................................................................... 1840 System Clock Characteristics with ADC Operation ............................................. 1842 System Clock Characteristics with USB Operation ............................................. 1842 Wake from Sleep Characteristics ...................................................................... 1843 Wake from Deep Sleep Characteristics ............................................................. 1843 Hibernation Module Battery Characteristics ....................................................... 1845 Hibernation Module Characteristics ................................................................... 1845 Hibernation Module Tamper I/O Characteristics ................................................. 1845 Flash Memory Characteristics ........................................................................... 1847 EEPROM Characteristics ................................................................................. 1848 Fast GPIO Module Characteristics .................................................................... 1849 Slow GPIO Module Characteristics ................................................................... 1850 Pad Voltage/Current Characteristics for Hibernate WAKE Pin ............................. 1851 June 18, 2014 21 Texas Instruments-Production Data Table of Contents Table 27-37. Table 27-38. Table 27-39. Table 27-40. Table 27-41. Table 27-42. Table 27-43. Table 27-44. Table 27-45. Table 27-46. Table 27-47. Table 27-48. Table 27-49. Table 27-50. Table 27-51. Table 27-52. Table 27-53. Table 27-54. Table 27-55. Table 27-56. Table 27-57. Table 27-58. Table 27-59. Table 27-60. Table 27-61. Table 27-62. Table 27-63. Table 27-64. Non-Power I/O Pad Voltage/Current Characteristics .......................................... 1852 EPI Interface Load Conditions .......................................................................... 1853 EPI SDRAM Characteristics ............................................................................. 1853 EPI SDRAM Interface Characteristics ............................................................... 1853 EPI Host-Bus 8 and Host-Bus 16 Interface Characteristics ................................. 1855 EPI General-Purpose Interface Characteristics .................................................. 1857 EPI PSRAM Interface Characteristics ................................................................ 1858 ADC Electrical Characteristics for ADC at 1 Msps .............................................. 1861 ADC Electrical Characteristics for ADC at 2 Msps .............................................. 1863 SSI Characteristics .......................................................................................... 1867 Bi- and Quad-SSI Characteristics ...................................................................... 1869 I2C Characteristics ........................................................................................... 1870 Ethernet PHY DC Characteristics ...................................................................... 1871 MOSC 25-MHz Crystal Specification ................................................................. 1871 a MOSC Single-Ended 25-MHz Oscillator Specification ....................................... 1871 Ethernet Controller Enable and Software Reset Timing ...................................... 1872 100Base-TX Transmit Timing (tR/F and Jitter) ..................................................... 1872 10Base-T Normal Link Pulse Timing ................................................................. 1873 Auto-Negotiation Fast Link Pulse (FLP) Timing .................................................. 1874 100Base-TX Signal Detect Timing ..................................................................... 1874 ULPI Interface Timing ....................................................................................... 1875 Analog Comparator Characteristics ................................................................... 1877 Analog Comparator Voltage Reference Characteristics ...................................... 1877 Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 0 .......................................................................................................... 1877 Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 1 .......................................................................................................... 1878 PWM Timing Characteristics ............................................................................. 1879 Current Consumption ....................................................................................... 1880 Peripheral Current Consumption ....................................................................... 1884 22 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller List of Registers The Cortex-M4F Processor ........................................................................................................... 80 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Cortex General-Purpose Register 0 (R0) ........................................................................... 88 Cortex General-Purpose Register 1 (R1) ........................................................................... 88 Cortex General-Purpose Register 2 (R2) ........................................................................... 88 Cortex General-Purpose Register 3 (R3) ........................................................................... 88 Cortex General-Purpose Register 4 (R4) ........................................................................... 88 Cortex General-Purpose Register 5 (R5) ........................................................................... 88 Cortex General-Purpose Register 6 (R6) ........................................................................... 88 Cortex General-Purpose Register 7 (R7) ........................................................................... 88 Cortex General-Purpose Register 8 (R8) ........................................................................... 88 Cortex General-Purpose Register 9 (R9) ........................................................................... 88 Cortex General-Purpose Register 10 (R10) ....................................................................... 88 Cortex General-Purpose Register 11 (R11) ........................................................................ 88 Cortex General-Purpose Register 12 (R12) ....................................................................... 88 Stack Pointer (SP) ........................................................................................................... 89 Link Register (LR) ............................................................................................................ 90 Program Counter (PC) ..................................................................................................... 91 Program Status Register (PSR) ........................................................................................ 92 Priority Mask Register (PRIMASK) .................................................................................... 96 Fault Mask Register (FAULTMASK) .................................................................................. 97 Base Priority Mask Register (BASEPRI) ............................................................................ 98 Control Register (CONTROL) ........................................................................................... 99 Floating-Point Status Control (FPSC) .............................................................................. 101 Cortex-M4 Peripherals ................................................................................................................. 134 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: SysTick Control and Status Register (STCTRL), offset 0x010 ........................................... 150 SysTick Reload Value Register (STRELOAD), offset 0x014 .............................................. 152 SysTick Current Value Register (STCURRENT), offset 0x018 ........................................... 153 Interrupt 0-31 Set Enable (EN0), offset 0x100 .................................................................. 154 Interrupt 32-63 Set Enable (EN1), offset 0x104 ................................................................ 154 Interrupt 64-95 Set Enable (EN2), offset 0x108 ................................................................ 154 Interrupt 96-113 Set Enable (EN3), offset 0x10C .............................................................. 154 Interrupt 0-31 Clear Enable (DIS0), offset 0x180 .............................................................. 155 Interrupt 32-63 Clear Enable (DIS1), offset 0x184 ............................................................ 155 Interrupt 64-95 Clear Enable (DIS2), offset 0x188 ............................................................ 155 Interrupt 96-113 Clear Enable (DIS3), offset 0x18C .......................................................... 155 Interrupt 0-31 Set Pending (PEND0), offset 0x200 ........................................................... 156 Interrupt 32-63 Set Pending (PEND1), offset 0x204 ......................................................... 156 Interrupt 64-95 Set Pending (PEND2), offset 0x208 ......................................................... 156 Interrupt 96-113 Set Pending (PEND3), offset 0x20C ....................................................... 156 Interrupt 0-31 Clear Pending (UNPEND0), offset 0x280 ................................................... 157 Interrupt 32-63 Clear Pending (UNPEND1), offset 0x284 .................................................. 157 Interrupt 64-95 Clear Pending (UNPEND2), offset 0x288 .................................................. 157 Interrupt 96-113 Clear Pending (UNPEND3), offset 0x28C ............................................... 157 Interrupt 0-31 Active Bit (ACTIVE0), offset 0x300 ............................................................. 158 Interrupt 32-63 Active Bit (ACTIVE1), offset 0x304 ........................................................... 158 June 18, 2014 23 Texas Instruments-Production Data Table of Contents Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: Register 44: Register 45: Register 46: Register 47: Register 48: Register 49: Register 50: Register 51: Register 52: Register 53: Register 54: Register 55: Register 56: Register 57: Register 58: Register 59: Register 60: Register 61: Register 62: Register 63: Register 64: Register 65: Register 66: Register 67: Register 68: Register 69: Interrupt 64-95 Active Bit (ACTIVE2), offset 0x308 ........................................................... 158 Interrupt 96-127 Active Bit (ACTIVE3), offset 0x30C ........................................................ 158 Interrupt 0-3 Priority (PRI0), offset 0x400 ......................................................................... 159 Interrupt 4-7 Priority (PRI1), offset 0x404 ......................................................................... 159 Interrupt 8-11 Priority (PRI2), offset 0x408 ....................................................................... 159 Interrupt 12-15 Priority (PRI3), offset 0x40C .................................................................... 159 Interrupt 16-19 Priority (PRI4), offset 0x410 ..................................................................... 159 Interrupt 20-23 Priority (PRI5), offset 0x414 ..................................................................... 159 Interrupt 24-27 Priority (PRI6), offset 0x418 ..................................................................... 159 Interrupt 28-31 Priority (PRI7), offset 0x41C .................................................................... 159 Interrupt 32-35 Priority (PRI8), offset 0x420 ..................................................................... 159 Interrupt 36-39 Priority (PRI9), offset 0x424 ..................................................................... 159 Interrupt 40-43 Priority (PRI10), offset 0x428 ................................................................... 159 Interrupt 44-47 Priority (PRI11), offset 0x42C ................................................................... 159 Interrupt 48-51 Priority (PRI12), offset 0x430 ................................................................... 159 Interrupt 52-55 Priority (PRI13), offset 0x434 ................................................................... 159 Interrupt 56-59 Priority (PRI14), offset 0x438 ................................................................... 159 Interrupt 60-63 Priority (PRI15), offset 0x43C .................................................................. 159 Interrupt 64-67 Priority (PRI16), offset 0x440 ................................................................... 161 Interrupt 68-71 Priority (PRI17), offset 0x444 ................................................................... 161 Interrupt 72-75 Priority (PRI18), offset 0x448 ................................................................... 161 Interrupt 76-79 Priority (PRI19), offset 0x44C .................................................................. 161 Interrupt 80-83 Priority (PRI20), offset 0x450 ................................................................... 161 Interrupt 84-87 Priority (PRI21), offset 0x454 ................................................................... 161 Interrupt 88-91 Priority (PRI22), offset 0x458 ................................................................... 161 Interrupt 92-95 Priority (PRI23), offset 0x45C .................................................................. 161 Interrupt 96-99 Priority (PRI24), offset 0x460 ................................................................... 161 Interrupt 100-103 Priority (PRI25), offset 0x464 ............................................................... 161 Interrupt 104-107 Priority (PRI26), offset 0x468 ............................................................... 161 Interrupt 108-111 Priority (PRI27), offset 0x46C ............................................................... 161 Interrupt 112-113 Priority (PRI28), offset 0x470 ................................................................ 161 Software Trigger Interrupt (SWTRIG), offset 0xF00 .......................................................... 163 Auxiliary Control (ACTLR), offset 0x008 .......................................................................... 164 CPU ID Base (CPUID), offset 0xD00 ............................................................................... 166 Interrupt Control and State (INTCTRL), offset 0xD04 ........................................................ 167 Vector Table Offset (VTABLE), offset 0xD08 .................................................................... 170 Application Interrupt and Reset Control (APINT), offset 0xD0C ......................................... 171 System Control (SYSCTRL), offset 0xD10 ....................................................................... 173 Configuration and Control (CFGCTRL), offset 0xD14 ....................................................... 175 System Handler Priority 1 (SYSPRI1), offset 0xD18 ......................................................... 177 System Handler Priority 2 (SYSPRI2), offset 0xD1C ........................................................ 178 System Handler Priority 3 (SYSPRI3), offset 0xD20 ......................................................... 179 System Handler Control and State (SYSHNDCTRL), offset 0xD24 .................................... 180 Configurable Fault Status (FAULTSTAT), offset 0xD28 ..................................................... 184 Hard Fault Status (HFAULTSTAT), offset 0xD2C .............................................................. 190 Memory Management Fault Address (MMADDR), offset 0xD34 ........................................ 191 Bus Fault Address (FAULTADDR), offset 0xD38 .............................................................. 192 MPU Type (MPUTYPE), offset 0xD90 ............................................................................. 193 24 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 70: Register 71: Register 72: Register 73: Register 74: Register 75: Register 76: Register 77: Register 78: Register 79: Register 80: Register 81: Register 82: Register 83: MPU Control (MPUCTRL), offset 0xD94 .......................................................................... 194 MPU Region Number (MPUNUMBER), offset 0xD98 ....................................................... 196 MPU Region Base Address (MPUBASE), offset 0xD9C ................................................... 197 MPU Region Base Address Alias 1 (MPUBASE1), offset 0xDA4 ....................................... 197 MPU Region Base Address Alias 2 (MPUBASE2), offset 0xDAC ...................................... 197 MPU Region Base Address Alias 3 (MPUBASE3), offset 0xDB4 ....................................... 197 MPU Region Attribute and Size (MPUATTR), offset 0xDA0 ............................................... 199 MPU Region Attribute and Size Alias 1 (MPUATTR1), offset 0xDA8 .................................. 199 MPU Region Attribute and Size Alias 2 (MPUATTR2), offset 0xDB0 .................................. 199 MPU Region Attribute and Size Alias 3 (MPUATTR3), offset 0xDB8 .................................. 199 Coprocessor Access Control (CPAC), offset 0xD88 .......................................................... 202 Floating-Point Context Control (FPCC), offset 0xF34 ........................................................ 203 Floating-Point Context Address (FPCA), offset 0xF38 ...................................................... 205 Floating-Point Default Status Control (FPDSC), offset 0xF3C ........................................... 206 System Control ............................................................................................................................ 220 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Device Identification 0 (DID0), offset 0x000 ..................................................................... 255 Device Identification 1 (DID1), offset 0x004 ..................................................................... 257 Power-Temp Brown Out Control (PTBOCTL), offset 0x038 ............................................... 259 Raw Interrupt Status (RIS), offset 0x050 .......................................................................... 261 Interrupt Mask Control (IMC), offset 0x054 ...................................................................... 263 Masked Interrupt Status and Clear (MISC), offset 0x058 .................................................. 265 Reset Cause (RESC), offset 0x05C ................................................................................ 267 Power-Temperature Cause (PWRTC), offset 0x060 ......................................................... 270 NMI Cause Register (NMIC), offset 0x064 ....................................................................... 271 Main Oscillator Control (MOSCCTL), offset 0x07C ........................................................... 273 Run and Sleep Mode Configuration Register (RSCLKCFG), offset 0x0B0 .......................... 275 Memory Timing Parameter Register 0 for Main Flash and EEPROM (MEMTIM0), offset 0x0C0 ........................................................................................................................... 277 Alternate Clock Configuration (ALTCLKCFG), offset 0x138 ............................................... 280 Deep Sleep Clock Configuration Register (DSCLKCFG), offset 0x144 ............................... 281 Divisor and Source Clock Configuration (DIVSCLK), offset 0x148 ..................................... 284 System Properties (SYSPROP), offset 0x14C .................................................................. 286 Precision Internal Oscillator Calibration (PIOSCCAL), offset 0x150 ................................... 289 Precision Internal Oscillator Statistics (PIOSCSTAT), offset 0x154 .................................... 291 PLL Frequency 0 (PLLFREQ0), offset 0x160 ................................................................... 292 PLL Frequency 1 (PLLFREQ1), offset 0x164 ................................................................... 293 PLL Status (PLLSTAT), offset 0x168 ............................................................................... 294 Sleep Power Configuration (SLPPWRCFG), offset 0x188 ................................................. 295 Deep-Sleep Power Configuration (DSLPPWRCFG), offset 0x18C ..................................... 297 Non-Volatile Memory Information (NVMSTAT), offset 0x1A0 ............................................. 299 LDO Sleep Power Control (LDOSPCTL), offset 0x1B4 ..................................................... 300 LDO Sleep Power Calibration (LDOSPCAL), offset 0x1B8 ................................................ 302 LDO Deep-Sleep Power Control (LDODPCTL), offset 0x1BC ........................................... 303 LDO Deep-Sleep Power Calibration (LDODPCAL), offset 0x1C0 ...................................... 305 Sleep / Deep-Sleep Power Mode Status (SDPMST), offset 0x1CC .................................... 306 Reset Behavior Control Register (RESBEHAVCTL), offset 0x1D8 ..................................... 309 Hardware System Service Request (HSSR), offset 0x1F4 ................................................ 311 USB Power Domain Status (USBPDS), offset 0x280 ........................................................ 312 June 18, 2014 25 Texas Instruments-Production Data Table of Contents Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: Register 44: Register 45: Register 46: Register 47: Register 48: Register 49: Register 50: Register 51: Register 52: Register 53: Register 54: Register 55: Register 56: Register 57: Register 58: Register 59: Register 60: Register 61: Register 62: Register 63: Register 64: Register 65: Register 66: Register 67: Register 68: Register 69: Register 70: Register 71: Register 72: Register 73: Register 74: Register 75: Register 76: Register 77: Register 78: Register 79: USB Memory Power Control (USBMPC), offset 0x284 ..................................................... 313 Ethernet MAC Power Domain Status (EMACPDS), offset 0x288 ....................................... 314 Ethernet MAC Memory Power Control (EMACMPC), offset 0x28C .................................... 315 CAN 0 Power Domain Status (CAN0PDS), offset 0x298 ................................................... 316 CAN 0 Memory Power Control (CAN0MPC), offset 0x29C ................................................ 317 CAN 1 Power Domain Status (CAN1PDS), offset 0x2A0 .................................................. 318 CAN 1 Memory Power Control (CAN1MPC), offset 0x2A4 ................................................ 319 Watchdog Timer Peripheral Present (PPWD), offset 0x300 ............................................... 320 16/32-Bit General-Purpose Timer Peripheral Present (PPTIMER), offset 0x304 ................. 321 General-Purpose Input/Output Peripheral Present (PPGPIO), offset 0x308 ........................ 323 Micro Direct Memory Access Peripheral Present (PPDMA), offset 0x30C .......................... 326 EPI Peripheral Present (PPEPI), offset 0x310 .................................................................. 327 Hibernation Peripheral Present (PPHIB), offset 0x314 ...................................................... 328 Universal Asynchronous Receiver/Transmitter Peripheral Present (PPUART), offset 0x318 ........................................................................................................................... 329 Synchronous Serial Interface Peripheral Present (PPSSI), offset 0x31C ............................ 331 Inter-Integrated Circuit Peripheral Present (PPI2C), offset 0x320 ...................................... 333 Universal Serial Bus Peripheral Present (PPUSB), offset 0x328 ........................................ 335 Ethernet PHY Peripheral Present (PPEPHY), offset 0x330 ............................................... 336 Controller Area Network Peripheral Present (PPCAN), offset 0x334 .................................. 337 Analog-to-Digital Converter Peripheral Present (PPADC), offset 0x338 ............................. 338 Analog Comparator Peripheral Present (PPACMP), offset 0x33C ...................................... 339 Pulse Width Modulator Peripheral Present (PPPWM), offset 0x340 ................................... 340 Quadrature Encoder Interface Peripheral Present (PPQEI), offset 0x344 ........................... 341 Low Pin Count Interface Peripheral Present (PPLPC), offset 0x348 .................................. 342 Platform Environment Control Interface Peripheral Present (PPPECI), offset 0x350 ........... 343 Fan Control Peripheral Present (PPFAN), offset 0x354 ..................................................... 344 EEPROM Peripheral Present (PPEEPROM), offset 0x358 ................................................ 345 32/64-Bit Wide General-Purpose Timer Peripheral Present (PPWTIMER), offset 0x35C ..... 346 Remote Temperature Sensor Peripheral Present (PPRTS), offset 0x370 ........................... 347 CRC Module Peripheral Present (PPCCM), offset 0x374 .................................................. 348 LCD Peripheral Present (PPLCD), offset 0x390 ............................................................... 349 1-Wire Peripheral Present (PPOWIRE), offset 0x398 ....................................................... 350 Ethernet MAC Peripheral Present (PPEMAC), offset 0x39C ............................................. 351 Power Regulator Bus Peripheral Present (PPPRB), offset 0x3A0 ...................................... 352 Human Interface Master Peripheral Present (PPHIM), offset 0x3A4 .................................. 353 Watchdog Timer Software Reset (SRWD), offset 0x500 ................................................... 354 16/32-Bit General-Purpose Timer Software Reset (SRTIMER), offset 0x504 ...................... 355 General-Purpose Input/Output Software Reset (SRGPIO), offset 0x508 ............................ 357 Micro Direct Memory Access Software Reset (SRDMA), offset 0x50C ............................... 360 EPI Software Reset (SREPI), offset 0x510 ...................................................................... 361 Hibernation Software Reset (SRHIB), offset 0x514 ........................................................... 362 Universal Asynchronous Receiver/Transmitter Software Reset (SRUART), offset 0x518 .... 363 Synchronous Serial Interface Software Reset (SRSSI), offset 0x51C ................................ 365 Inter-Integrated Circuit Software Reset (SRI2C), offset 0x520 ........................................... 367 Universal Serial Bus Software Reset (SRUSB), offset 0x528 ............................................ 369 Ethernet PHY Software Reset (SREPHY), offset 0x530 .................................................... 370 Controller Area Network Software Reset (SRCAN), offset 0x534 ....................................... 371 26 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 80: Register 81: Register 82: Register 83: Register 84: Register 85: Register 86: Register 87: Register 88: Register 89: Register 90: Register 91: Register 92: Register 93: Register 94: Register 95: Register 96: Register 97: Register 98: Register 99: Register 100: Register 101: Register 102: Register 103: Register 104: Register 105: Register 106: Register 107: Register 108: Register 109: Register 110: Register 111: Register 112: Register 113: Register 114: Register 115: Register 116: Register 117: Analog-to-Digital Converter Software Reset (SRADC), offset 0x538 .................................. 372 Analog Comparator Software Reset (SRACMP), offset 0x53C .......................................... 373 Pulse Width Modulator Software Reset (SRPWM), offset 0x540 ....................................... 374 Quadrature Encoder Interface Software Reset (SRQEI), offset 0x544 ............................... 375 EEPROM Software Reset (SREEPROM), offset 0x558 .................................................... 376 CRC Module Software Reset (SRCCM), offset 0x574 ...................................................... 377 Ethernet MAC Software Reset (SREMAC), offset 0x59C .................................................. 378 Watchdog Timer Run Mode Clock Gating Control (RCGCWD), offset 0x600 ...................... 379 16/32-Bit General-Purpose Timer Run Mode Clock Gating Control (RCGCTIMER), offset 0x604 ........................................................................................................................... 380 General-Purpose Input/Output Run Mode Clock Gating Control (RCGCGPIO), offset 0x608 ........................................................................................................................... 382 Micro Direct Memory Access Run Mode Clock Gating Control (RCGCDMA), offset 0x60C ........................................................................................................................... 385 EPI Run Mode Clock Gating Control (RCGCEPI), offset 0x610 ......................................... 386 Hibernation Run Mode Clock Gating Control (RCGCHIB), offset 0x614 ............................. 387 Universal Asynchronous Receiver/Transmitter Run Mode Clock Gating Control (RCGCUART), offset 0x618 .................................................................................................................. 388 Synchronous Serial Interface Run Mode Clock Gating Control (RCGCSSI), offset 0x61C ........................................................................................................................... 390 Inter-Integrated Circuit Run Mode Clock Gating Control (RCGCI2C), offset 0x620 ............. 391 Universal Serial Bus Run Mode Clock Gating Control (RCGCUSB), offset 0x628 ............... 393 Ethernet PHY Run Mode Clock Gating Control (RCGCEPHY), offset 0x630 ...................... 394 Controller Area Network Run Mode Clock Gating Control (RCGCCAN), offset 0x634 ......... 395 Analog-to-Digital Converter Run Mode Clock Gating Control (RCGCADC), offset 0x638 .... 396 Analog Comparator Run Mode Clock Gating Control (RCGCACMP), offset 0x63C ............. 397 Pulse Width Modulator Run Mode Clock Gating Control (RCGCPWM), offset 0x640 .......... 398 Quadrature Encoder Interface Run Mode Clock Gating Control (RCGCQEI), offset 0x644 ........................................................................................................................... 399 EEPROM Run Mode Clock Gating Control (RCGCEEPROM), offset 0x658 ....................... 400 CRC Module Run Mode Clock Gating Control (RCGCCCM), offset 0x674 ......................... 401 Ethernet MAC Run Mode Clock Gating Control (RCGCEMAC), offset 0x69C ..................... 402 Watchdog Timer Sleep Mode Clock Gating Control (SCGCWD), offset 0x700 .................... 403 16/32-Bit General-Purpose Timer Sleep Mode Clock Gating Control (SCGCTIMER), offset 0x704 ........................................................................................................................... 404 General-Purpose Input/Output Sleep Mode Clock Gating Control (SCGCGPIO), offset 0x708 ........................................................................................................................... 406 Micro Direct Memory Access Sleep Mode Clock Gating Control (SCGCDMA), offset 0x70C ........................................................................................................................... 409 EPI Sleep Mode Clock Gating Control (SCGCEPI), offset 0x710 ....................................... 410 Hibernation Sleep Mode Clock Gating Control (SCGCHIB), offset 0x714 ........................... 411 Universal Asynchronous Receiver/Transmitter Sleep Mode Clock Gating Control (SCGCUART), offset 0x718 ............................................................................................ 412 Synchronous Serial Interface Sleep Mode Clock Gating Control (SCGCSSI), offset 0x71C ........................................................................................................................... 414 Inter-Integrated Circuit Sleep Mode Clock Gating Control (SCGCI2C), offset 0x720 ........... 415 Universal Serial Bus Sleep Mode Clock Gating Control (SCGCUSB), offset 0x728 ............. 417 Ethernet PHY Sleep Mode Clock Gating Control (SCGCEPHY), offset 0x730 .................... 418 Controller Area Network Sleep Mode Clock Gating Control (SCGCCAN), offset 0x734 ....... 419 June 18, 2014 27 Texas Instruments-Production Data Table of Contents Register 118: Analog-to-Digital Converter Sleep Mode Clock Gating Control (SCGCADC), offset 0x738 ........................................................................................................................... 420 Register 119: Analog Comparator Sleep Mode Clock Gating Control (SCGCACMP), offset 0x73C .......... 421 Register 120: Pulse Width Modulator Sleep Mode Clock Gating Control (SCGCPWM), offset 0x740 ........ 422 Register 121: Quadrature Encoder Interface Sleep Mode Clock Gating Control (SCGCQEI), offset 0x744 ........................................................................................................................... 423 Register 122: EEPROM Sleep Mode Clock Gating Control (SCGCEEPROM), offset 0x758 ..................... 424 Register 123: CRC Module Sleep Mode Clock Gating Control (SCGCCCM), offset 0x774 ....................... 425 Register 124: Ethernet MAC Sleep Mode Clock Gating Control (SCGCEMAC), offset 0x79C .................. 426 Register 125: Watchdog Timer Deep-Sleep Mode Clock Gating Control (DCGCWD), offset 0x800 .......... 427 Register 126: 16/32-Bit General-Purpose Timer Deep-Sleep Mode Clock Gating Control (DCGCTIMER), offset 0x804 .................................................................................................................. 428 Register 127: General-Purpose Input/Output Deep-Sleep Mode Clock Gating Control (DCGCGPIO), offset 0x808 ........................................................................................................................... 430 Register 128: Micro Direct Memory Access Deep-Sleep Mode Clock Gating Control (DCGCDMA), offset 0x80C ........................................................................................................................... 433 Register 129: EPI Deep-Sleep Mode Clock Gating Control (DCGCEPI), offset 0x810 ............................. 434 Register 130: Hibernation Deep-Sleep Mode Clock Gating Control (DCGCHIB), offset 0x814 .................. 435 Register 131: Universal Asynchronous Receiver/Transmitter Deep-Sleep Mode Clock Gating Control (DCGCUART), offset 0x818 ............................................................................................ 436 Register 132: Synchronous Serial Interface Deep-Sleep Mode Clock Gating Control (DCGCSSI), offset 0x81C ........................................................................................................................... 438 Register 133: Inter-Integrated Circuit Deep-Sleep Mode Clock Gating Control (DCGCI2C), offset 0x820 ........................................................................................................................... 439 Register 134: Universal Serial Bus Deep-Sleep Mode Clock Gating Control (DCGCUSB), offset 0x828 ........................................................................................................................... 441 Register 135: Ethernet PHY Deep-Sleep Mode Clock Gating Control (DCGCEPHY), offset 0x830 ........... 442 Register 136: Controller Area Network Deep-Sleep Mode Clock Gating Control (DCGCCAN), offset 0x834 ........................................................................................................................... 443 Register 137: Analog-to-Digital Converter Deep-Sleep Mode Clock Gating Control (DCGCADC), offset 0x838 ........................................................................................................................... 444 Register 138: Analog Comparator Deep-Sleep Mode Clock Gating Control (DCGCACMP), offset 0x83C ........................................................................................................................... 445 Register 139: Pulse Width Modulator Deep-Sleep Mode Clock Gating Control (DCGCPWM), offset 0x840 ........................................................................................................................... 446 Register 140: Quadrature Encoder Interface Deep-Sleep Mode Clock Gating Control (DCGCQEI), offset 0x844 ........................................................................................................................... 447 Register 141: EEPROM Deep-Sleep Mode Clock Gating Control (DCGCEEPROM), offset 0x858 ........... 448 Register 142: CRC Module Deep-Sleep Mode Clock Gating Control (DCGCCCM), offset 0x874 .............. 449 Register 143: Ethernet MAC Deep-Sleep Mode Clock Gating Control (DCGCEMAC), offset 0x89C ......... 450 Register 144: Watchdog Timer Power Control (PCWD), offset 0x900 ..................................................... 451 Register 145: 16/32-Bit General-Purpose Timer Power Control (PCTIMER), offset 0x904 ....................... 453 Register 146: General-Purpose Input/Output Power Control (PCGPIO), offset 0x908 .............................. 456 Register 147: Micro Direct Memory Access Power Control (PCDMA), offset 0x90C ................................ 461 Register 148: External Peripheral Interface Power Control (PCEPI), offset 0x910 ................................... 463 Register 149: Hibernation Power Control (PCHIB), offset 0x914 ............................................................ 465 Register 150: Universal Asynchronous Receiver/Transmitter Power Control (PCUART), offset 0x918 ...... 467 Register 151: Synchronous Serial Interface Power Control (PCSSI), offset 0x91C .................................. 470 Register 152: Inter-Integrated Circuit Power Control (PCI2C), offset 0x920 ............................................ 472 28 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 153: Register 154: Register 155: Register 156: Register 157: Register 158: Register 159: Register 160: Register 161: Register 162: Register 163: Register 164: Register 165: Register 166: Register 167: Register 168: Register 169: Register 170: Register 171: Register 172: Register 173: Register 174: Register 175: Register 176: Register 177: Register 178: Register 179: Register 180: Register 181: Register 182: Register 183: Register 184: Register 185: Universal Serial Bus Power Control (PCUSB), offset 0x928 .............................................. 476 Ethernet PHY Power Control (PCEPHY), offset 0x930 ..................................................... 478 Controller Area Network Power Control (PCCAN), offset 0x934 ........................................ 480 Analog-to-Digital Converter Power Control (PCADC), offset 0x938 .................................... 482 Analog Comparator Power Control (PCACMP), offset 0x93C ............................................ 484 Pulse Width Modulator Power Control (PCPWM), offset 0x940 ......................................... 486 Quadrature Encoder Interface Power Control (PCQEI), offset 0x944 ................................. 488 EEPROM Power Control (PCEEPROM), offset 0x958 ...................................................... 490 CRC Module Power Control (PCCCM), offset 0x974 ........................................................ 492 Ethernet MAC Power Control (PCEMAC), offset 0x99C .................................................... 494 Watchdog Timer Peripheral Ready (PRWD), offset 0xA00 ................................................ 496 16/32-Bit General-Purpose Timer Peripheral Ready (PRTIMER), offset 0xA04 ................... 497 General-Purpose Input/Output Peripheral Ready (PRGPIO), offset 0xA08 ......................... 499 Micro Direct Memory Access Peripheral Ready (PRDMA), offset 0xA0C ........................... 502 EPI Peripheral Ready (PREPI), offset 0xA10 ................................................................... 503 Hibernation Peripheral Ready (PRHIB), offset 0xA14 ....................................................... 504 Universal Asynchronous Receiver/Transmitter Peripheral Ready (PRUART), offset 0xA18 ........................................................................................................................... 505 Synchronous Serial Interface Peripheral Ready (PRSSI), offset 0xA1C ............................. 507 Inter-Integrated Circuit Peripheral Ready (PRI2C), offset 0xA20 ....................................... 509 Universal Serial Bus Peripheral Ready (PRUSB), offset 0xA28 ......................................... 512 Ethernet PHY Peripheral Ready (PREPHY), offset 0xA30 ................................................ 513 Controller Area Network Peripheral Ready (PRCAN), offset 0xA34 ................................... 514 Analog-to-Digital Converter Peripheral Ready (PRADC), offset 0xA38 ............................... 515 Analog Comparator Peripheral Ready (PRACMP), offset 0xA3C ....................................... 516 Pulse Width Modulator Peripheral Ready (PRPWM), offset 0xA40 .................................... 517 Quadrature Encoder Interface Peripheral Ready (PRQEI), offset 0xA44 ............................ 518 EEPROM Peripheral Ready (PREEPROM), offset 0xA58 ................................................. 519 CRC Module Peripheral Ready (PRCCM), offset 0xA74 ................................................... 520 Ethernet MAC Peripheral Ready (PREMAC), offset 0xA9C ............................................... 521 Unique ID 0 (UNIQUEID0), offset 0xF20 .......................................................................... 522 Unique ID 1 (UNIQUEID1), offset 0xF24 .......................................................................... 522 Unique ID 2 (UNIQUEID2), offset 0xF28 .......................................................................... 522 Unique ID 3 (UNIQUEID3), offset 0xF2C ......................................................................... 522 Processor Support and Exception Module ............................................................................... 523 Register 1: Register 2: Register 3: Register 4: System Exception Raw Interrupt Status (SYSEXCRIS), offset 0x000 ................................ System Exception Interrupt Mask (SYSEXCIM), offset 0x004 ........................................... System Exception Masked Interrupt Status (SYSEXCMIS), offset 0x008 ........................... System Exception Interrupt Clear (SYSEXCIC), offset 0x00C ........................................... 524 526 528 530 Hibernation Module ..................................................................................................................... 531 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Hibernation RTC Counter (HIBRTCC), offset 0x000 ......................................................... Hibernation RTC Match 0 (HIBRTCM0), offset 0x004 ....................................................... Hibernation RTC Load (HIBRTCLD), offset 0x00C ........................................................... Hibernation Control (HIBCTL), offset 0x010 ..................................................................... Hibernation Interrupt Mask (HIBIM), offset 0x014 ............................................................. Hibernation Raw Interrupt Status (HIBRIS), offset 0x018 .................................................. Hibernation Masked Interrupt Status (HIBMIS), offset 0x01C ............................................ Hibernation Interrupt Clear (HIBIC), offset 0x020 ............................................................. June 18, 2014 554 555 556 557 562 564 566 568 29 Texas Instruments-Production Data Table of Contents Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Hibernation RTC Trim (HIBRTCT), offset 0x024 ............................................................... 570 Hibernation RTC Sub Seconds (HIBRTCSS), offset 0x028 ............................................... 571 Hibernation IO Configuration (HIBIO), offset 0x02C .......................................................... 572 Hibernation Data (HIBDATA), offset 0x030-0x06F ............................................................ 574 Hibernation Calendar Control (HIBCALCTL), offset 0x300 ................................................ 575 Hibernation Calendar 0 (HIBCAL0), offset 0x310 ............................................................. 576 Hibernation Calendar 1 (HIBCAL1), offset 0x314 ............................................................. 578 Hibernation Calendar Load 0 (HIBCALLD0), offset 0x320 ................................................. 580 Hibernation Calendar Load (HIBCALLD1), offset 0x324 ................................................... 582 Hibernation Calendar Match 0 (HIBCALM0), offset 0x330 ................................................ 583 Hibernation Calendar Match 1 (HIBCALM1), offset 0x334 ................................................ 585 Hibernation Lock (HIBLOCK), offset 0x360 ...................................................................... 586 HIB Tamper Control (HIBTPCTL), offset 0x400 ................................................................ 587 HIB Tamper Status (HIBTPSTAT), offset 0x404 ................................................................ 589 HIB Tamper I/O Control (HIBTPIO), offset 0x410 ............................................................. 591 HIB Tamper Log 0 (HIBTPLOG0), offset 0x4E0 ................................................................ 595 HIB Tamper Log 2 (HIBTPLOG2), offset 0x4E8 ................................................................ 595 HIB Tamper Log 4 (HIBTPLOG4), offset 0x4F0 ................................................................ 595 HIB Tamper Log 6 (HIBTPLOG6), offset 0x4F8 ................................................................ 595 HIB Tamper Log 1 (HIBTPLOG1), offset 0x4E4 ................................................................ 596 HIB Tamper Log 3 (HIBTPLOG3), offset 0x4EC ............................................................... 596 HIB Tamper Log 5 (HIBTPLOG5), offset 0x4F4 ................................................................ 596 HIB Tamper Log 7 (HIBTPLOG7), offset 0x4FC ............................................................... 596 Hibernation Peripheral Properties (HIBPP) , offset 0xFC0 ................................................. 598 Hibernation Clock Control (HIBCC), offset 0xFC8 ............................................................ 599 Internal Memory ........................................................................................................................... 600 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Flash Memory Address (FMA), offset 0x000 .................................................................... 625 Flash Memory Data (FMD), offset 0x004 ......................................................................... 626 Flash Memory Control (FMC), offset 0x008 ..................................................................... 627 Flash Controller Raw Interrupt Status (FCRIS), offset 0x00C ............................................ 630 Flash Controller Interrupt Mask (FCIM), offset 0x010 ........................................................ 633 Flash Controller Masked Interrupt Status and Clear (FCMISC), offset 0x014 ..................... 635 Flash Memory Control 2 (FMC2), offset 0x020 ................................................................. 638 Flash Write Buffer Valid (FWBVAL), offset 0x030 ............................................................. 639 Flash Program/Erase Key (FLPEKEY), offset 0x03C ........................................................ 640 Flash Write Buffer n (FWBn), offset 0x100 - 0x17C .......................................................... 641 Flash Peripheral Properties (FLASHPP), offset 0xFC0 ..................................................... 642 SRAM Size (SSIZE), offset 0xFC4 .................................................................................. 644 Flash Configuration Register (FLASHCONF), offset 0xFC8 .............................................. 645 ROM Third-Party Software (ROMSWMAP), offset 0xFCC ................................................. 647 Flash DMA Address Size (FLASHDMASZ), offset 0xFD0 ................................................. 649 Flash DMA Starting Address (FLASHDMAST), offset 0xFD4 ............................................ 650 EEPROM Size Information (EESIZE), offset 0x000 .......................................................... 651 EEPROM Current Block (EEBLOCK), offset 0x004 .......................................................... 652 EEPROM Current Offset (EEOFFSET), offset 0x008 ........................................................ 653 EEPROM Read-Write (EERDWR), offset 0x010 .............................................................. 654 EEPROM Read-Write with Increment (EERDWRINC), offset 0x014 .................................. 655 EEPROM Done Status (EEDONE), offset 0x018 .............................................................. 656 30 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: Register 44: Register 45: Register 46: Register 47: Register 48: Register 49: Register 50: Register 51: Register 52: Register 53: Register 54: Register 55: Register 56: Register 57: Register 58: Register 59: Register 60: Register 61: Register 62: Register 63: Register 64: Register 65: Register 66: Register 67: Register 68: Register 69: Register 70: EEPROM Support Control and Status (EESUPP), offset 0x01C ........................................ 658 EEPROM Unlock (EEUNLOCK), offset 0x020 .................................................................. 659 EEPROM Protection (EEPROT), offset 0x030 ................................................................. 660 EEPROM Password (EEPASS0), offset 0x034 ................................................................. 662 EEPROM Password (EEPASS1), offset 0x038 ................................................................. 662 EEPROM Password (EEPASS2), offset 0x03C ................................................................ 662 EEPROM Interrupt (EEINT), offset 0x040 ........................................................................ 663 EEPROM Block Hide 0 (EEHIDE0), offset 0x050 ............................................................. 664 EEPROM Block Hide 1 (EEHIDE1), offset 0x054 ............................................................. 665 EEPROM Block Hide 2 (EEHIDE2), offset 0x058 ............................................................. 665 EEPROM Debug Mass Erase (EEDBGME), offset 0x080 ................................................. 666 EEPROM Peripheral Properties (EEPROMPP), offset 0xFC0 ........................................... 667 Reset Vector Pointer (RVP), offset 0x0D4 ........................................................................ 668 Flash Memory Protection Read Enable 0 (FMPRE0), offset 0x200 .................................... 669 Flash Memory Protection Read Enable 1 (FMPRE1), offset 0x204 .................................... 669 Flash Memory Protection Read Enable 2 (FMPRE2), offset 0x208 .................................... 669 Flash Memory Protection Read Enable 3 (FMPRE3), offset 0x20C ................................... 669 Flash Memory Protection Read Enable 4 (FMPRE4), offset 0x210 .................................... 669 Flash Memory Protection Read Enable 5 (FMPRE5), offset 0x214 .................................... 669 Flash Memory Protection Read Enable 6 (FMPRE6), offset 0x218 .................................... 669 Flash Memory Protection Read Enable 7 (FMPRE7), offset 0x21C ................................... 669 Flash Memory Protection Read Enable 8 (FMPRE8), offset 0x220 .................................... 669 Flash Memory Protection Read Enable 9 (FMPRE9), offset 0x224 .................................... 669 Flash Memory Protection Read Enable 10 (FMPRE10), offset 0x228 ................................ 669 Flash Memory Protection Read Enable 11 (FMPRE11), offset 0x22C ................................ 669 Flash Memory Protection Read Enable 12 (FMPRE12), offset 0x230 ................................ 669 Flash Memory Protection Read Enable 13 (FMPRE13), offset 0x234 ................................ 669 Flash Memory Protection Read Enable 14 (FMPRE14), offset 0x238 ................................ 669 Flash Memory Protection Read Enable 15 (FMPRE15), offset 0x23C ................................ 669 Flash Memory Protection Program Enable 0 (FMPPE0), offset 0x400 ............................... 671 Flash Memory Protection Program Enable 1 (FMPPE1), offset 0x404 ............................... 671 Flash Memory Protection Program Enable 2 (FMPPE2), offset 0x408 ............................... 671 Flash Memory Protection Program Enable 3 (FMPPE3), offset 0x40C ............................... 671 Flash Memory Protection Program Enable 4 (FMPPE4), offset 0x410 ............................... 671 Flash Memory Protection Program Enable 5 (FMPPE5), offset 0x414 ............................... 671 Flash Memory Protection Program Enable 6 (FMPPE6), offset 0x418 ............................... 671 Flash Memory Protection Program Enable 7 (FMPPE7), offset 0x41C ............................... 671 Flash Memory Protection Program Enable 8 (FMPPE8), offset 0x420 ............................... 671 Flash Memory Protection Program Enable 9 (FMPPE9), offset 0x424 ............................... 671 Flash Memory Protection Program Enable 10 (FMPPE10), offset 0x428 ............................ 671 Flash Memory Protection Program Enable 11 (FMPPE11), offset 0x42C ............................ 671 Flash Memory Protection Program Enable 12 (FMPPE12), offset 0x430 ............................ 671 Flash Memory Protection Program Enable 13 (FMPPE13), offset 0x434 ............................ 671 Flash Memory Protection Program Enable 14 (FMPPE14), offset 0x438 ............................ 671 Flash Memory Protection Program Enable 15 (FMPPE15), offset 0x43C ........................... 671 Boot Configuration (BOOTCFG), offset 0x1D0 ................................................................. 674 User Register 0 (USER_REG0), offset 0x1E0 .................................................................. 677 User Register 1 (USER_REG1), offset 0x1E4 .................................................................. 677 June 18, 2014 31 Texas Instruments-Production Data Table of Contents Register 71: Register 72: User Register 2 (USER_REG2), offset 0x1E8 .................................................................. 677 User Register 3 (USER_REG3), offset 0x1EC ................................................................. 677 Micro Direct Memory Access (μDMA) ........................................................................................ 678 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: DMA Channel Source Address End Pointer (DMASRCENDP), offset 0x000 ...................... 703 DMA Channel Destination Address End Pointer (DMADSTENDP), offset 0x004 ................ 704 DMA Channel Control Word (DMACHCTL), offset 0x008 .................................................. 705 DMA Status (DMASTAT), offset 0x000 ............................................................................ 710 DMA Configuration (DMACFG), offset 0x004 ................................................................... 712 DMA Channel Control Base Pointer (DMACTLBASE), offset 0x008 .................................. 713 DMA Alternate Channel Control Base Pointer (DMAALTBASE), offset 0x00C .................... 714 DMA Channel Wait-on-Request Status (DMAWAITSTAT), offset 0x010 ............................. 715 DMA Channel Software Request (DMASWREQ), offset 0x014 ......................................... 716 DMA Channel Useburst Set (DMAUSEBURSTSET), offset 0x018 .................................... 717 DMA Channel Useburst Clear (DMAUSEBURSTCLR), offset 0x01C ................................. 718 DMA Channel Request Mask Set (DMAREQMASKSET), offset 0x020 .............................. 719 DMA Channel Request Mask Clear (DMAREQMASKCLR), offset 0x024 ........................... 720 DMA Channel Enable Set (DMAENASET), offset 0x028 ................................................... 721 DMA Channel Enable Clear (DMAENACLR), offset 0x02C ............................................... 722 DMA Channel Primary Alternate Set (DMAALTSET), offset 0x030 .................................... 723 DMA Channel Primary Alternate Clear (DMAALTCLR), offset 0x034 ................................. 724 DMA Channel Priority Set (DMAPRIOSET), offset 0x038 ................................................. 725 DMA Channel Priority Clear (DMAPRIOCLR), offset 0x03C .............................................. 726 DMA Bus Error Clear (DMAERRCLR), offset 0x04C ........................................................ 727 DMA Channel Assignment (DMACHASGN), offset 0x500 ................................................. 728 DMA Channel Map Select 0 (DMACHMAP0), offset 0x510 ............................................... 729 DMA Channel Map Select 1 (DMACHMAP1), offset 0x514 ............................................... 730 DMA Channel Map Select 2 (DMACHMAP2), offset 0x518 ............................................... 731 DMA Channel Map Select 3 (DMACHMAP3), offset 0x51C .............................................. 732 DMA Peripheral Identification 0 (DMAPeriphID0), offset 0xFE0 ......................................... 733 DMA Peripheral Identification 1 (DMAPeriphID1), offset 0xFE4 ......................................... 734 DMA Peripheral Identification 2 (DMAPeriphID2), offset 0xFE8 ......................................... 735 DMA Peripheral Identification 3 (DMAPeriphID3), offset 0xFEC ........................................ 736 DMA Peripheral Identification 4 (DMAPeriphID4), offset 0xFD0 ......................................... 737 DMA PrimeCell Identification 0 (DMAPCellID0), offset 0xFF0 ........................................... 738 DMA PrimeCell Identification 1 (DMAPCellID1), offset 0xFF4 ........................................... 739 DMA PrimeCell Identification 2 (DMAPCellID2), offset 0xFF8 ........................................... 740 DMA PrimeCell Identification 3 (DMAPCellID3), offset 0xFFC ........................................... 741 General-Purpose Input/Outputs (GPIOs) ................................................................................... 742 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: GPIO Data (GPIODATA), offset 0x000 ............................................................................ 759 GPIO Direction (GPIODIR), offset 0x400 ......................................................................... 760 GPIO Interrupt Sense (GPIOIS), offset 0x404 .................................................................. 761 GPIO Interrupt Both Edges (GPIOIBE), offset 0x408 ........................................................ 762 GPIO Interrupt Event (GPIOIEV), offset 0x40C ................................................................ 763 GPIO Interrupt Mask (GPIOIM), offset 0x410 ................................................................... 764 GPIO Raw Interrupt Status (GPIORIS), offset 0x414 ........................................................ 765 GPIO Masked Interrupt Status (GPIOMIS), offset 0x418 ................................................... 767 GPIO Interrupt Clear (GPIOICR), offset 0x41C ................................................................ 769 GPIO Alternate Function Select (GPIOAFSEL), offset 0x420 ............................................ 770 32 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: GPIO 2-mA Drive Select (GPIODR2R), offset 0x500 ........................................................ 772 GPIO 4-mA Drive Select (GPIODR4R), offset 0x504 ........................................................ 773 GPIO 8-mA Drive Select (GPIODR8R), offset 0x508 ........................................................ 774 GPIO Open Drain Select (GPIOODR), offset 0x50C ......................................................... 775 GPIO Pull-Up Select (GPIOPUR), offset 0x510 ................................................................ 776 GPIO Pull-Down Select (GPIOPDR), offset 0x514 ........................................................... 778 GPIO Slew Rate Control Select (GPIOSLR), offset 0x518 ................................................ 780 GPIO Digital Enable (GPIODEN), offset 0x51C ................................................................ 781 GPIO Lock (GPIOLOCK), offset 0x520 ............................................................................ 783 GPIO Commit (GPIOCR), offset 0x524 ............................................................................ 784 GPIO Analog Mode Select (GPIOAMSEL), offset 0x528 ................................................... 786 GPIO Port Control (GPIOPCTL), offset 0x52C ................................................................. 787 GPIO ADC Control (GPIOADCCTL), offset 0x530 ............................................................ 789 GPIO DMA Control (GPIODMACTL), offset 0x534 ........................................................... 790 GPIO Select Interrupt (GPIOSI), offset 0x538 .................................................................. 791 GPIO 12-mA Drive Select (GPIODR12R), offset 0x53C .................................................... 792 GPIO Wake Pin Enable (GPIOWAKEPEN), offset 0x540 .................................................. 793 GPIO Wake Level (GPIOWAKELVL), offset 0x544 ........................................................... 795 GPIO Wake Status (GPIOWAKESTAT), offset 0x548 ....................................................... 797 GPIO Peripheral Property (GPIOPP), offset 0xFC0 .......................................................... 799 GPIO Peripheral Configuration (GPIOPC), offset 0xFC4 ................................................... 800 GPIO Peripheral Identification 4 (GPIOPeriphID4), offset 0xFD0 ....................................... 803 GPIO Peripheral Identification 5 (GPIOPeriphID5), offset 0xFD4 ....................................... 804 GPIO Peripheral Identification 6 (GPIOPeriphID6), offset 0xFD8 ....................................... 805 GPIO Peripheral Identification 7 (GPIOPeriphID7), offset 0xFDC ...................................... 806 GPIO Peripheral Identification 0 (GPIOPeriphID0), offset 0xFE0 ....................................... 807 GPIO Peripheral Identification 1 (GPIOPeriphID1), offset 0xFE4 ....................................... 808 GPIO Peripheral Identification 2 (GPIOPeriphID2), offset 0xFE8 ....................................... 809 GPIO Peripheral Identification 3 (GPIOPeriphID3), offset 0xFEC ...................................... 810 GPIO PrimeCell Identification 0 (GPIOPCellID0), offset 0xFF0 .......................................... 811 GPIO PrimeCell Identification 1 (GPIOPCellID1), offset 0xFF4 .......................................... 812 GPIO PrimeCell Identification 2 (GPIOPCellID2), offset 0xFF8 .......................................... 813 GPIO PrimeCell Identification 3 (GPIOPCellID3), offset 0xFFC ......................................... 814 External Peripheral Interface (EPI) ............................................................................................. 815 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: EPI Configuration (EPICFG), offset 0x000 ....................................................................... 857 EPI Main Baud Rate (EPIBAUD), offset 0x004 ................................................................. 859 EPI Main Baud Rate (EPIBAUD2), offset 0x008 ............................................................... 861 EPI SDRAM Configuration (EPISDRAMCFG), offset 0x010 .............................................. 863 EPI Host-Bus 8 Configuration (EPIHB8CFG), offset 0x010 ............................................... 865 EPI Host-Bus 16 Configuration (EPIHB16CFG), offset 0x010 ........................................... 870 EPI General-Purpose Configuration (EPIGPCFG), offset 0x010 ........................................ 876 EPI Host-Bus 8 Configuration 2 (EPIHB8CFG2), offset 0x014 .......................................... 879 EPI Host-Bus 16 Configuration 2 (EPIHB16CFG2), offset 0x014 ....................................... 885 EPI Address Map (EPIADDRMAP), offset 0x01C ............................................................. 892 EPI Read Size 0 (EPIRSIZE0), offset 0x020 .................................................................... 895 EPI Read Size 1 (EPIRSIZE1), offset 0x030 .................................................................... 895 EPI Read Address 0 (EPIRADDR0), offset 0x024 ............................................................ 896 EPI Read Address 1 (EPIRADDR1), offset 0x034 ............................................................ 896 June 18, 2014 33 Texas Instruments-Production Data Table of Contents Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: Register 44: Register 45: Register 46: EPI Non-Blocking Read Data 0 (EPIRPSTD0), offset 0x028 ............................................. 897 EPI Non-Blocking Read Data 1 (EPIRPSTD1), offset 0x038 ............................................. 897 EPI Status (EPISTAT), offset 0x060 ................................................................................ 899 EPI Read FIFO Count (EPIRFIFOCNT), offset 0x06C ...................................................... 901 EPI Read FIFO (EPIREADFIFO0), offset 0x070 ............................................................... 902 EPI Read FIFO Alias 1 (EPIREADFIFO1), offset 0x074 .................................................... 902 EPI Read FIFO Alias 2 (EPIREADFIFO2), offset 0x078 .................................................... 902 EPI Read FIFO Alias 3 (EPIREADFIFO3), offset 0x07C ................................................... 902 EPI Read FIFO Alias 4 (EPIREADFIFO4), offset 0x080 .................................................... 902 EPI Read FIFO Alias 5 (EPIREADFIFO5), offset 0x084 .................................................... 902 EPI Read FIFO Alias 6 (EPIREADFIFO6), offset 0x088 .................................................... 902 EPI Read FIFO Alias 7 (EPIREADFIFO7), offset 0x08C ................................................... 902 EPI FIFO Level Selects (EPIFIFOLVL), offset 0x200 ........................................................ 903 EPI Write FIFO Count (EPIWFIFOCNT), offset 0x204 ...................................................... 905 EPI DMA Transmit Count (EPIDMATXCNT), offset 0x208 ................................................. 906 EPI Interrupt Mask (EPIIM), offset 0x210 ......................................................................... 907 EPI Raw Interrupt Status (EPIRIS), offset 0x214 .............................................................. 909 EPI Masked Interrupt Status (EPIMIS), offset 0x218 ........................................................ 911 EPI Error and Interrupt Status and Clear (EPIEISC), offset 0x21C .................................... 913 EPI Host-Bus 8 Configuration 3 (EPIHB8CFG3), offset 0x308 .......................................... 915 EPI Host-Bus 16 Configuration 3 (EPIHB16CFG3), offset 0x308 ....................................... 918 EPI Host-Bus 8 Configuration 4 (EPIHB8CFG4), offset 0x30C .......................................... 922 EPI Host-Bus 16 Configuration 4 (EPIHB16CFG4), offset 0x30C ...................................... 925 EPI Host-Bus 8 Timing Extension (EPIHB8TIME), offset 0x310 ......................................... 929 EPI Host-Bus 16 Timing Extension (EPIHB16TIME), offset 0x310 ..................................... 931 EPI Host-Bus 8 Timing Extension (EPIHB8TIME2), offset 0x314 ....................................... 933 EPI Host-Bus 16 Timing Extension (EPIHB16TIME2), offset 0x314 ................................... 935 EPI Host-Bus 8 Timing Extension (EPIHB8TIME3), offset 0x318 ....................................... 937 EPI Host-Bus 16 Timing Extension (EPIHB16TIME3), offset 0x318 ................................... 939 EPI Host-Bus 8 Timing Extension (EPIHB8TIME4), offset 0x31C ...................................... 941 EPI Host-Bus 16 Timing Extension (EPIHB16TIME4), offset 0x31C .................................. 943 EPI Host-Bus PSRAM (EPIHBPSRAM), offset 0x360 ....................................................... 945 Cyclical Redundancy Check (CRC) ............................................................................................ 946 Register 1: Register 2: Register 3: Register 4: CRC Control (CRCCTRL), offset 0x400 ........................................................................... 950 CRC SEED/Context (CRCSEED), offset 0x410 ................................................................ 952 CRC Data Input (CRCDIN), offset 0x414 ......................................................................... 953 CRC Post Processing Result (CRCRSLTPP), offset 0x418 ............................................... 954 General-Purpose Timers ............................................................................................................. 955 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: GPTM Configuration (GPTMCFG), offset 0x000 .............................................................. 976 GPTM Timer A Mode (GPTMTAMR), offset 0x004 ........................................................... 977 GPTM Timer B Mode (GPTMTBMR), offset 0x008 ........................................................... 982 GPTM Control (GPTMCTL), offset 0x00C ........................................................................ 986 GPTM Synchronize (GPTMSYNC), offset 0x010 .............................................................. 990 GPTM Interrupt Mask (GPTMIMR), offset 0x018 .............................................................. 993 GPTM Raw Interrupt Status (GPTMRIS), offset 0x01C ..................................................... 996 GPTM Masked Interrupt Status (GPTMMIS), offset 0x020 ................................................ 999 GPTM Interrupt Clear (GPTMICR), offset 0x024 ............................................................ 1002 GPTM Timer A Interval Load (GPTMTAILR), offset 0x028 .............................................. 1004 34 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: GPTM Timer B Interval Load (GPTMTBILR), offset 0x02C .............................................. 1005 GPTM Timer A Match (GPTMTAMATCHR), offset 0x030 ................................................ 1006 GPTM Timer B Match (GPTMTBMATCHR), offset 0x034 ................................................ 1007 GPTM Timer A Prescale (GPTMTAPR), offset 0x038 ..................................................... 1008 GPTM Timer B Prescale (GPTMTBPR), offset 0x03C ..................................................... 1009 GPTM TimerA Prescale Match (GPTMTAPMR), offset 0x040 ......................................... 1010 GPTM TimerB Prescale Match (GPTMTBPMR), offset 0x044 ......................................... 1011 GPTM Timer A (GPTMTAR), offset 0x048 ..................................................................... 1012 GPTM Timer B (GPTMTBR), offset 0x04C ..................................................................... 1013 GPTM Timer A Value (GPTMTAV), offset 0x050 ............................................................. 1014 GPTM Timer B Value (GPTMTBV), offset 0x054 ............................................................ 1015 GPTM RTC Predivide (GPTMRTCPD), offset 0x058 ...................................................... 1016 GPTM Timer A Prescale Snapshot (GPTMTAPS), offset 0x05C ...................................... 1017 GPTM Timer B Prescale Snapshot (GPTMTBPS), offset 0x060 ...................................... 1018 GPTM DMA Event (GPTMDMAEV), offset 0x06C .......................................................... 1019 GPTM ADC Event (GPTMADCEV), offset 0x070 ........................................................... 1022 GPTM Peripheral Properties (GPTMPP), offset 0xFC0 ................................................... 1025 GPTM Clock Configuration (GPTMCC), offset 0xFC8 ..................................................... 1027 Watchdog Timers ....................................................................................................................... 1028 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Watchdog Load (WDTLOAD), offset 0x000 .................................................................... 1032 Watchdog Value (WDTVALUE), offset 0x004 ................................................................. 1033 Watchdog Control (WDTCTL), offset 0x008 ................................................................... 1034 Watchdog Interrupt Clear (WDTICR), offset 0x00C ......................................................... 1036 Watchdog Raw Interrupt Status (WDTRIS), offset 0x010 ................................................ 1037 Watchdog Masked Interrupt Status (WDTMIS), offset 0x014 ........................................... 1038 Watchdog Test (WDTTEST), offset 0x418 ...................................................................... 1039 Watchdog Lock (WDTLOCK), offset 0xC00 .................................................................... 1040 Watchdog Peripheral Identification 4 (WDTPeriphID4), offset 0xFD0 ............................... 1041 Watchdog Peripheral Identification 5 (WDTPeriphID5), offset 0xFD4 ............................... 1042 Watchdog Peripheral Identification 6 (WDTPeriphID6), offset 0xFD8 ............................... 1043 Watchdog Peripheral Identification 7 (WDTPeriphID7), offset 0xFDC .............................. 1044 Watchdog Peripheral Identification 0 (WDTPeriphID0), offset 0xFE0 ............................... 1045 Watchdog Peripheral Identification 1 (WDTPeriphID1), offset 0xFE4 ............................... 1046 Watchdog Peripheral Identification 2 (WDTPeriphID2), offset 0xFE8 ............................... 1047 Watchdog Peripheral Identification 3 (WDTPeriphID3), offset 0xFEC ............................... 1048 Watchdog PrimeCell Identification 0 (WDTPCellID0), offset 0xFF0 .................................. 1049 Watchdog PrimeCell Identification 1 (WDTPCellID1), offset 0xFF4 .................................. 1050 Watchdog PrimeCell Identification 2 (WDTPCellID2), offset 0xFF8 .................................. 1051 Watchdog PrimeCell Identification 3 (WDTPCellID3 ), offset 0xFFC ................................ 1052 Analog-to-Digital Converter (ADC) ........................................................................................... 1053 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: ADC Active Sample Sequencer (ADCACTSS), offset 0x000 ........................................... ADC Raw Interrupt Status (ADCRIS), offset 0x004 ......................................................... ADC Interrupt Mask (ADCIM), offset 0x008 .................................................................... ADC Interrupt Status and Clear (ADCISC), offset 0x00C ................................................ ADC Overflow Status (ADCOSTAT), offset 0x010 .......................................................... ADC Event Multiplexer Select (ADCEMUX), offset 0x014 ............................................... ADC Underflow Status (ADCUSTAT), offset 0x018 ......................................................... ADC Trigger Source Select (ADCTSSEL), offset 0x01C ................................................. June 18, 2014 1077 1079 1082 1085 1089 1091 1096 1097 35 Texas Instruments-Production Data Table of Contents Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: Register 44: Register 45: Register 46: Register 47: Register 48: Register 49: Register 50: Register 51: Register 52: Register 53: ADC Sample Sequencer Priority (ADCSSPRI), offset 0x020 ........................................... 1099 ADC Sample Phase Control (ADCSPC), offset 0x024 .................................................... 1101 ADC Processor Sample Sequence Initiate (ADCPSSI), offset 0x028 ............................... 1103 ADC Sample Averaging Control (ADCSAC), offset 0x030 ............................................... 1105 ADC Digital Comparator Interrupt Status and Clear (ADCDCISC), offset 0x034 ............... 1106 ADC Control (ADCCTL), offset 0x038 ............................................................................ 1108 ADC Sample Sequence Input Multiplexer Select 0 (ADCSSMUX0), offset 0x040 ............. 1109 ADC Sample Sequence Control 0 (ADCSSCTL0), offset 0x044 ...................................... 1111 ADC Sample Sequence Result FIFO 0 (ADCSSFIFO0), offset 0x048 .............................. 1118 ADC Sample Sequence Result FIFO 1 (ADCSSFIFO1), offset 0x068 .............................. 1118 ADC Sample Sequence Result FIFO 2 (ADCSSFIFO2), offset 0x088 .............................. 1118 ADC Sample Sequence Result FIFO 3 (ADCSSFIFO3), offset 0x0A8 ............................. 1118 ADC Sample Sequence FIFO 0 Status (ADCSSFSTAT0), offset 0x04C ........................... 1119 ADC Sample Sequence FIFO 1 Status (ADCSSFSTAT1), offset 0x06C ........................... 1119 ADC Sample Sequence FIFO 2 Status (ADCSSFSTAT2), offset 0x08C .......................... 1119 ADC Sample Sequence FIFO 3 Status (ADCSSFSTAT3), offset 0x0AC .......................... 1119 ADC Sample Sequence 0 Operation (ADCSSOP0), offset 0x050 .................................... 1121 ADC Sample Sequence 0 Digital Comparator Select (ADCSSDC0), offset 0x054 ............. 1123 ADC Sample Sequence Extended Input Multiplexer Select 0 (ADCSSEMUX0), offset 0x058 .......................................................................................................................... 1125 ADC Sample Sequence 0 Sample and Hold Time (ADCSSTSH0), offset 0x05C .............. 1127 ADC Sample Sequence Input Multiplexer Select 1 (ADCSSMUX1), offset 0x060 ............. 1129 ADC Sample Sequence Input Multiplexer Select 2 (ADCSSMUX2), offset 0x080 ............. 1129 ADC Sample Sequence Control 1 (ADCSSCTL1), offset 0x064 ...................................... 1130 ADC Sample Sequence Control 2 (ADCSSCTL2), offset 0x084 ...................................... 1130 ADC Sample Sequence 1 Operation (ADCSSOP1), offset 0x070 .................................... 1134 ADC Sample Sequence 2 Operation (ADCSSOP2), offset 0x090 ................................... 1134 ADC Sample Sequence 1 Digital Comparator Select (ADCSSDC1), offset 0x074 ............. 1135 ADC Sample Sequence 2 Digital Comparator Select (ADCSSDC2), offset 0x094 ............ 1135 ADC Sample Sequence Extended Input Multiplexer Select 1 (ADCSSEMUX1), offset 0x078 .......................................................................................................................... 1137 ADC Sample Sequence Extended Input Multiplexer Select 2 (ADCSSEMUX2), offset 0x098 .................................................................................................................................... 1137 ADC Sample Sequence 1 Sample and Hold Time (ADCSSTSH1), offset 0x07C .............. 1139 ADC Sample Sequence 2 Sample and Hold Time (ADCSSTSH2), offset 0x09C .............. 1139 ADC Sample Sequence Input Multiplexer Select 3 (ADCSSMUX3), offset 0x0A0 ............. 1141 ADC Sample Sequence Control 3 (ADCSSCTL3), offset 0x0A4 ...................................... 1142 ADC Sample Sequence 3 Operation (ADCSSOP3), offset 0x0B0 .................................... 1144 ADC Sample Sequence 3 Digital Comparator Select (ADCSSDC3), offset 0x0B4 ............ 1145 ADC Sample Sequence Extended Input Multiplexer Select 3 (ADCSSEMUX3), offset 0x0B8 ......................................................................................................................... 1146 ADC Sample Sequence 3 Sample and Hold Time (ADCSSTSH3), offset 0x0BC .............. 1147 ADC Digital Comparator Reset Initial Conditions (ADCDCRIC), offset 0xD00 ................... 1148 ADC Digital Comparator Control 0 (ADCDCCTL0), offset 0xE00 ..................................... 1153 ADC Digital Comparator Control 1 (ADCDCCTL1), offset 0xE04 ..................................... 1153 ADC Digital Comparator Control 2 (ADCDCCTL2), offset 0xE08 ..................................... 1153 ADC Digital Comparator Control 3 (ADCDCCTL3), offset 0xE0C .................................... 1153 ADC Digital Comparator Control 4 (ADCDCCTL4), offset 0xE10 ..................................... 1153 ADC Digital Comparator Control 5 (ADCDCCTL5), offset 0xE14 ..................................... 1153 36 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 54: Register 55: Register 56: Register 57: Register 58: Register 59: Register 60: Register 61: Register 62: Register 63: Register 64: Register 65: Register 66: ADC Digital Comparator Control 6 (ADCDCCTL6), offset 0xE18 ..................................... ADC Digital Comparator Control 7 (ADCDCCTL7), offset 0xE1C .................................... ADC Digital Comparator Range 0 (ADCDCCMP0), offset 0xE40 ..................................... ADC Digital Comparator Range 1 (ADCDCCMP1), offset 0xE44 ..................................... ADC Digital Comparator Range 2 (ADCDCCMP2), offset 0xE48 ..................................... ADC Digital Comparator Range 3 (ADCDCCMP3), offset 0xE4C .................................... ADC Digital Comparator Range 4 (ADCDCCMP4), offset 0xE50 ..................................... ADC Digital Comparator Range 5 (ADCDCCMP5), offset 0xE54 ..................................... ADC Digital Comparator Range 6 (ADCDCCMP6), offset 0xE58 ..................................... ADC Digital Comparator Range 7 (ADCDCCMP7), offset 0xE5C .................................... ADC Peripheral Properties (ADCPP), offset 0xFC0 ........................................................ ADC Peripheral Configuration (ADCPC), offset 0xFC4 ................................................... ADC Clock Configuration (ADCCC), offset 0xFC8 .......................................................... 1153 1153 1156 1156 1156 1156 1156 1156 1156 1156 1157 1159 1160 Universal Asynchronous Receivers/Transmitters (UARTs) ................................................... 1161 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: UART Data (UARTDR), offset 0x000 ............................................................................. 1175 UART Receive Status/Error Clear (UARTRSR/UARTECR), offset 0x004 ......................... 1177 UART Flag (UARTFR), offset 0x018 .............................................................................. 1180 UART IrDA Low-Power Register (UARTILPR), offset 0x020 ............................................ 1183 UART Integer Baud-Rate Divisor (UARTIBRD), offset 0x024 .......................................... 1184 UART Fractional Baud-Rate Divisor (UARTFBRD), offset 0x028 ..................................... 1185 UART Line Control (UARTLCRH), offset 0x02C ............................................................. 1186 UART Control (UARTCTL), offset 0x030 ........................................................................ 1188 UART Interrupt FIFO Level Select (UARTIFLS), offset 0x034 .......................................... 1192 UART Interrupt Mask (UARTIM), offset 0x038 ................................................................ 1194 UART Raw Interrupt Status (UARTRIS), offset 0x03C .................................................... 1198 UART Masked Interrupt Status (UARTMIS), offset 0x040 ............................................... 1202 UART Interrupt Clear (UARTICR), offset 0x044 .............................................................. 1206 UART DMA Control (UARTDMACTL), offset 0x048 ........................................................ 1208 UART 9-Bit Self Address (UART9BITADDR), offset 0x0A4 ............................................. 1209 UART 9-Bit Self Address Mask (UART9BITAMASK), offset 0x0A8 .................................. 1210 UART Peripheral Properties (UARTPP), offset 0xFC0 .................................................... 1211 UART Clock Configuration (UARTCC), offset 0xFC8 ...................................................... 1213 UART Peripheral Identification 4 (UARTPeriphID4), offset 0xFD0 ................................... 1214 UART Peripheral Identification 5 (UARTPeriphID5), offset 0xFD4 ................................... 1215 UART Peripheral Identification 6 (UARTPeriphID6), offset 0xFD8 ................................... 1216 UART Peripheral Identification 7 (UARTPeriphID7), offset 0xFDC ................................... 1217 UART Peripheral Identification 0 (UARTPeriphID0), offset 0xFE0 .................................... 1218 UART Peripheral Identification 1 (UARTPeriphID1), offset 0xFE4 .................................... 1219 UART Peripheral Identification 2 (UARTPeriphID2), offset 0xFE8 .................................... 1220 UART Peripheral Identification 3 (UARTPeriphID3), offset 0xFEC ................................... 1221 UART PrimeCell Identification 0 (UARTPCellID0), offset 0xFF0 ...................................... 1222 UART PrimeCell Identification 1 (UARTPCellID1), offset 0xFF4 ...................................... 1223 UART PrimeCell Identification 2 (UARTPCellID2), offset 0xFF8 ...................................... 1224 UART PrimeCell Identification 3 (UARTPCellID3), offset 0xFFC ...................................... 1225 Quad Synchronous Serial Interface (QSSI) ............................................................................. 1226 Register 1: Register 2: Register 3: QSSI Control 0 (SSICR0), offset 0x000 ......................................................................... 1245 QSSI Control 1 (SSICR1), offset 0x004 ......................................................................... 1247 QSSI Data (SSIDR), offset 0x008 ................................................................................. 1249 June 18, 2014 37 Texas Instruments-Production Data Table of Contents Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: QSSI Status (SSISR), offset 0x00C ............................................................................... 1250 QSSI Clock Prescale (SSICPSR), offset 0x010 .............................................................. 1252 QSSI Interrupt Mask (SSIIM), offset 0x014 .................................................................... 1253 QSSI Raw Interrupt Status (SSIRIS), offset 0x018 ......................................................... 1255 QSSI Masked Interrupt Status (SSIMIS), offset 0x01C ................................................... 1257 QSSI Interrupt Clear (SSIICR), offset 0x020 .................................................................. 1259 QSSI DMA Control (SSIDMACTL), offset 0x024 ............................................................. 1260 QSSI Peripheral Properties (SSIPP), offset 0xFC0 ......................................................... 1261 QSSI Clock Configuration (SSICC), offset 0xFC8 ........................................................... 1262 QSSI Peripheral Identification 4 (SSIPeriphID4), offset 0xFD0 ........................................ 1263 QSSI Peripheral Identification 5 (SSIPeriphID5), offset 0xFD4 ........................................ 1264 QSSI Peripheral Identification 6 (SSIPeriphID6), offset 0xFD8 ........................................ 1265 QSSI Peripheral Identification 7 (SSIPeriphID7), offset 0xFDC ........................................ 1266 QSSI Peripheral Identification 0 (SSIPeriphID0), offset 0xFE0 ........................................ 1267 QSSI Peripheral Identification 1 (SSIPeriphID1), offset 0xFE4 ........................................ 1268 QSSI Peripheral Identification 2 (SSIPeriphID2), offset 0xFE8 ........................................ 1269 QSSI Peripheral Identification 3 (SSIPeriphID3), offset 0xFEC ........................................ 1270 QSSI PrimeCell Identification 0 (SSIPCellID0), offset 0xFF0 ........................................... 1271 QSSI PrimeCell Identification 1 (SSIPCellID1), offset 0xFF4 ........................................... 1272 QSSI PrimeCell Identification 2 (SSIPCellID2), offset 0xFF8 ........................................... 1273 QSSI PrimeCell Identification 3 (SSIPCellID3), offset 0xFFC .......................................... 1274 Inter-Integrated Circuit (I2C) Interface ...................................................................................... 1275 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: I2C Master Slave Address (I2CMSA), offset 0x000 ......................................................... 1302 I2C Master Control/Status (I2CMCS), offset 0x004 ......................................................... 1303 I2C Master Data (I2CMDR), offset 0x008 ....................................................................... 1312 I2C Master Timer Period (I2CMTPR), offset 0x00C ......................................................... 1313 I2C Master Interrupt Mask (I2CMIMR), offset 0x010 ....................................................... 1315 I2C Master Raw Interrupt Status (I2CMRIS), offset 0x014 ............................................... 1318 I2C Master Masked Interrupt Status (I2CMMIS), offset 0x018 .......................................... 1321 I2C Master Interrupt Clear (I2CMICR), offset 0x01C ....................................................... 1324 I2C Master Configuration (I2CMCR), offset 0x020 .......................................................... 1326 I2C Master Clock Low Timeout Count (I2CMCLKOCNT), offset 0x024 ............................. 1327 I2C Master Bus Monitor (I2CMBMON), offset 0x02C ....................................................... 1328 I2C Master Burst Length (I2CMBLEN), offset 0x030 ....................................................... 1329 I2C Master Burst Count (I2CMBCNT), offset 0x034 ........................................................ 1330 I2C Slave Own Address (I2CSOAR), offset 0x800 .......................................................... 1331 I2C Slave Control/Status (I2CSCSR), offset 0x804 ......................................................... 1332 I2C Slave Data (I2CSDR), offset 0x808 ......................................................................... 1335 I2C Slave Interrupt Mask (I2CSIMR), offset 0x80C ......................................................... 1336 I2C Slave Raw Interrupt Status (I2CSRIS), offset 0x810 ................................................. 1338 I2C Slave Masked Interrupt Status (I2CSMIS), offset 0x814 ............................................ 1341 I2C Slave Interrupt Clear (I2CSICR), offset 0x818 .......................................................... 1344 I2C Slave Own Address 2 (I2CSOAR2), offset 0x81C ..................................................... 1346 I2C Slave ACK Control (I2CSACKCTL), offset 0x820 ...................................................... 1347 I2C FIFO Data (I2CFIFODATA), offset 0xF00 ................................................................. 1348 I2C FIFO Control (I2CFIFOCTL), offset 0xF04 ............................................................... 1350 I2C FIFO Status (I2CFIFOSTATUS), offset 0xF08 .......................................................... 1352 38 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 26: Register 27: I2C Peripheral Properties (I2CPP), offset 0xFC0 ............................................................ 1354 I2C Peripheral Configuration (I2CPC), offset 0xFC4 ....................................................... 1355 Controller Area Network (CAN) Module ................................................................................... 1356 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: CAN Control (CANCTL), offset 0x000 ............................................................................ 1378 CAN Status (CANSTS), offset 0x004 ............................................................................. 1380 CAN Error Counter (CANERR), offset 0x008 ................................................................. 1383 CAN Bit Timing (CANBIT), offset 0x00C ........................................................................ 1384 CAN Interrupt (CANINT), offset 0x010 ........................................................................... 1385 CAN Test (CANTST), offset 0x014 ................................................................................ 1386 CAN Baud Rate Prescaler Extension (CANBRPE), offset 0x018 ..................................... 1388 CAN IF1 Command Request (CANIF1CRQ), offset 0x020 .............................................. 1389 CAN IF2 Command Request (CANIF2CRQ), offset 0x080 .............................................. 1389 CAN IF1 Command Mask (CANIF1CMSK), offset 0x024 ................................................ 1390 CAN IF2 Command Mask (CANIF2CMSK), offset 0x084 ................................................ 1390 CAN IF1 Mask 1 (CANIF1MSK1), offset 0x028 .............................................................. 1393 CAN IF2 Mask 1 (CANIF2MSK1), offset 0x088 .............................................................. 1393 CAN IF1 Mask 2 (CANIF1MSK2), offset 0x02C .............................................................. 1394 CAN IF2 Mask 2 (CANIF2MSK2), offset 0x08C .............................................................. 1394 CAN IF1 Arbitration 1 (CANIF1ARB1), offset 0x030 ....................................................... 1396 CAN IF2 Arbitration 1 (CANIF2ARB1), offset 0x090 ....................................................... 1396 CAN IF1 Arbitration 2 (CANIF1ARB2), offset 0x034 ....................................................... 1397 CAN IF2 Arbitration 2 (CANIF2ARB2), offset 0x094 ....................................................... 1397 CAN IF1 Message Control (CANIF1MCTL), offset 0x038 ................................................ 1399 CAN IF2 Message Control (CANIF2MCTL), offset 0x098 ................................................ 1399 CAN IF1 Data A1 (CANIF1DA1), offset 0x03C ............................................................... 1402 CAN IF1 Data A2 (CANIF1DA2), offset 0x040 ................................................................ 1402 CAN IF1 Data B1 (CANIF1DB1), offset 0x044 ................................................................ 1402 CAN IF1 Data B2 (CANIF1DB2), offset 0x048 ................................................................ 1402 CAN IF2 Data A1 (CANIF2DA1), offset 0x09C ............................................................... 1402 CAN IF2 Data A2 (CANIF2DA2), offset 0x0A0 ............................................................... 1402 CAN IF2 Data B1 (CANIF2DB1), offset 0x0A4 ............................................................... 1402 CAN IF2 Data B2 (CANIF2DB2), offset 0x0A8 ............................................................... 1402 CAN Transmission Request 1 (CANTXRQ1), offset 0x100 .............................................. 1403 CAN Transmission Request 2 (CANTXRQ2), offset 0x104 .............................................. 1403 CAN New Data 1 (CANNWDA1), offset 0x120 ............................................................... 1404 CAN New Data 2 (CANNWDA2), offset 0x124 ............................................................... 1404 CAN Message 1 Interrupt Pending (CANMSG1INT), offset 0x140 ................................... 1405 CAN Message 2 Interrupt Pending (CANMSG2INT), offset 0x144 ................................... 1405 CAN Message 1 Valid (CANMSG1VAL), offset 0x160 ..................................................... 1406 CAN Message 2 Valid (CANMSG2VAL), offset 0x164 ..................................................... 1406 Ethernet Controller .................................................................................................................... 1407 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Ethernet MAC Configuration (EMACCFG), offset 0x000 ................................................. Ethernet MAC Frame Filter (EMACFRAMEFLTR), offset 0x004 ...................................... Ethernet MAC Hash Table High (EMACHASHTBLH), offset 0x008 .................................. Ethernet MAC Hash Table Low (EMACHASHTBLL), offset 0x00C ................................... Ethernet MAC MII Address (EMACMIIADDR), offset 0x010 ............................................ Ethernet MAC MII Data Register (EMACMIIDATA), offset 0x014 ..................................... Ethernet MAC Flow Control (EMACFLOWCTL), offset 0x018 ......................................... June 18, 2014 1471 1478 1482 1483 1484 1486 1487 39 Texas Instruments-Production Data Table of Contents Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: Register 44: Register 45: Register 46: Register 47: Register 48: Register 49: Ethernet MAC VLAN Tag (EMACVLANTG), offset 0x01C ............................................... 1489 Ethernet MAC Status (EMACSTATUS), offset 0x024 ...................................................... 1491 Ethernet MAC Remote Wake-Up Frame Filter (EMACRWUFF), offset 0x028 ................... 1494 Ethernet MAC PMT Control and Status Register (EMACPMTCTLSTAT), offset 0x02C ..... 1495 Ethernet MAC Raw Interrupt Status (EMACRIS), offset 0x038 ........................................ 1497 Ethernet MAC Interrupt Mask (EMACIM), offset 0x03C ................................................... 1499 Ethernet MAC Address 0 High (EMACADDR0H), offset 0x040 ........................................ 1500 Ethernet MAC Address 0 Low Register (EMACADDR0L), offset 0x044 ............................ 1501 Ethernet MAC Address 1 High (EMACADDR1H), offset 0x048 ........................................ 1502 Ethernet MAC Address 1 Low (EMACADDR1L), offset 0x04C ........................................ 1504 Ethernet MAC Address 2 High (EMACADDR2H), offset 0x050 ........................................ 1505 Ethernet MAC Address 2 Low (EMACADDR2L), offset 0x054 ......................................... 1507 Ethernet MAC Address 3 High (EMACADDR3H), offset 0x058 ........................................ 1508 Ethernet MAC Address 3 Low (EMACADDR3L), offset 0x05C ........................................ 1510 Ethernet MAC Watchdog Timeout (EMACWDOGTO), offset 0x0DC ................................ 1511 Ethernet MAC MMC Control (EMACMMCCTRL), offset 0x100 ........................................ 1512 Ethernet MAC MMC Receive Raw Interrupt Status (EMACMMCRXRIS), offset 0x104 ...... 1515 Ethernet MAC MMC Transmit Raw Interrupt Status (EMACMMCTXRIS), offset 0x108 ..... 1517 Ethernet MAC MMC Receive Interrupt Mask (EMACMMCRXIM), offset 0x10C ................ 1519 Ethernet MAC MMC Transmit Interrupt Mask (EMACMMCTXIM), offset 0x110 ................. 1521 Ethernet MAC Transmit Frame Count for Good and Bad Frames (EMACTXCNTGB), offset 0x118 .......................................................................................................................... 1523 Ethernet MAC Transmit Frame Count for Frames Transmitted after Single Collision (EMACTXCNTSCOL), offset 0x14C .............................................................................. 1524 Ethernet MAC Transmit Frame Count for Frames Transmitted after Multiple Collisions (EMACTXCNTMCOL), offset 0x150 .............................................................................. 1525 Ethernet MAC Transmit Octet Count Good (EMACTXOCTCNTG), offset 0x164 ............... 1526 Ethernet MAC Receive Frame Count for Good and Bad Frames (EMACRXCNTGB), offset 0x180 .......................................................................................................................... 1527 Ethernet MAC Receive Frame Count for CRC Error Frames (EMACRXCNTCRCERR), offset 0x194 .......................................................................................................................... 1528 Ethernet MAC Receive Frame Count for Alignment Error Frames (EMACRXCNTALGNERR), offset 0x198 ................................................................................................................. 1529 Ethernet MAC Receive Frame Count for Good Unicast Frames (EMACRXCNTGUNI), offset 0x1C4 ......................................................................................................................... 1530 Ethernet MAC VLAN Tag Inclusion or Replacement (EMACVLNINCREP), offset 0x584 .... 1531 Ethernet MAC VLAN Hash Table (EMACVLANHASH), offset 0x588 ................................ 1533 Ethernet MAC Timestamp Control (EMACTIMSTCTRL), offset 0x700 ............................. 1534 Ethernet MAC Sub-Second Increment (EMACSUBSECINC), offset 0x704 ....................... 1538 Ethernet MAC System Time - Seconds (EMACTIMSEC), offset 0x708 ............................ 1539 Ethernet MAC System Time - Nanoseconds (EMACTIMNANO), offset 0x70C .................. 1540 Ethernet MAC System Time - Seconds Update (EMACTIMSECU), offset 0x710 .............. 1541 Ethernet MAC System Time - Nanoseconds Update (EMACTIMNANOU), offset 0x714 .... 1542 Ethernet MAC Timestamp Addend (EMACTIMADD), offset 0x718 ................................... 1543 Ethernet MAC Target Time Seconds (EMACTARGSEC), offset 0x71C ............................ 1544 Ethernet MAC Target Time Nanoseconds (EMACTARGNANO), offset 0x720 ................... 1545 Ethernet MAC System Time-Higher Word Seconds (EMACHWORDSEC), offset 0x724 .... 1546 Ethernet MAC Timestamp Status (EMACTIMSTAT), offset 0x728 .................................... 1547 Ethernet MAC PPS Control (EMACPPSCTRL), offset 0x72C .......................................... 1548 40 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 50: Register 51: Register 52: Register 53: Register 54: Register 55: Register 56: Register 57: Register 58: Register 59: Register 60: Register 61: Register 62: Register 63: Register 64: Register 65: Register 66: Register 67: Register 68: Register 69: Register 70: Register 71: Register 72: Register 73: Register 74: Register 75: Register 76: Register 77: Register 78: Register 79: Register 80: Register 81: Register 82: Register 83: Register 84: Register 85: Register 86: Register 87: Register 88: Register 89: Register 90: Register 91: Register 92: Register 93: Register 94: Register 95: Ethernet MAC PPS0 Interval (EMACPPS0INTVL), offset 0x760 ...................................... 1551 Ethernet MAC PPS0 Width (EMACPPS0WIDTH), offset 0x764 ....................................... 1552 Ethernet MAC DMA Bus Mode (EMACDMABUSMOD), offset 0xC00 .............................. 1553 Ethernet MAC Transmit Poll Demand (EMACTXPOLLD), offset 0xC04 ............................ 1557 Ethernet MAC Receive Poll Demand (EMACRXPOLLD), offset 0xC08 ............................ 1558 Ethernet MAC Receive Descriptor List Address (EMACRXDLADDR), offset 0xC0C ......... 1559 Ethernet MAC Transmit Descriptor List Address (EMACTXDLADDR), offset 0xC10 ......... 1560 Ethernet MAC DMA Interrupt Status (EMACDMARIS), offset 0xC14 ................................ 1561 Ethernet MAC DMA Operation Mode (EMACDMAOPMODE), offset 0xC18 ..................... 1567 Ethernet MAC DMA Interrupt Mask Register (EMACDMAIM), offset 0xC1C ..................... 1572 Ethernet MAC Missed Frame and Buffer Overflow Counter (EMACMFBOC), offset 0xC20 ......................................................................................................................... 1575 Ethernet MAC Receive Interrupt Watchdog Timer (EMACRXINTWDT), offset 0xC24 ....... 1576 Ethernet MAC Current Host Transmit Descriptor (EMACHOSTXDESC), offset 0xC48 ...... 1577 Ethernet MAC Current Host Receive Descriptor (EMACHOSRXDESC), offset 0xC4C ...... 1578 Ethernet MAC Current Host Transmit Buffer Address (EMACHOSTXBA), offset 0xC50 .... 1579 Ethernet MAC Current Host Receive Buffer Address (EMACHOSRXBA), offset 0xC54 ..... 1580 Ethernet MAC Peripheral Property Register (EMACPP), offset 0xFC0 ............................. 1581 Ethernet MAC Peripheral Configuration Register (EMACPC), offset 0xFC4 ..................... 1582 Ethernet MAC Clock Configuration Register (EMACCC), offset 0xFC8 ............................ 1586 Ethernet PHY Raw Interrupt Status (EPHYRIS), offset 0xFD0 ......................................... 1587 Ethernet PHY Interrupt Mask (EPHYIM), offset 0xFD4 ................................................... 1588 Ethernet PHY Masked Interrupt Status and Clear (EPHYMISC), offset 0xFD8 ................. 1589 Ethernet PHY Basic Mode Control - MR0 (EPHYBMCR), address 0x000 ......................... 1590 Ethernet PHY Basic Mode Status - MR1 (EPHYBMSR), address 0x001 .......................... 1592 Ethernet PHY Identifier Register 1 - MR2 (EPHYID1), address 0x002 ............................. 1595 Ethernet PHY Identifier Register 2 - MR3 (EPHYID2), address 0x003 ............................. 1596 Ethernet PHY Auto-Negotiation Advertisement - MR4 (EPHYANA), address 0x004 .......... 1597 Ethernet PHY Auto-Negotiation Link Partner Ability - MR5 (EPHYANLPA), address 0x005 .......................................................................................................................... 1599 Ethernet PHY Auto-Negotiation Expansion - MR6 (EPHYANER), address 0x006 ............. 1601 Ethernet PHY Auto-Negotiation Next Page TX - MR7 (EPHYANNPTR), address 0x007 .... 1602 Ethernet PHY Auto-Negotiation Link Partner Ability Next Page - MR8 (EPHYANLNPTR), address 0x008 ............................................................................................................. 1604 Ethernet PHY Configuration 1 - MR9 (EPHYCFG1), address 0x009 ................................ 1606 Ethernet PHY Configuration 2 - MR10 (EPHYCFG2), address 0x00A .............................. 1609 Ethernet PHY Configuration 3 - MR11 (EPHYCFG3), address 0x00B .............................. 1611 Ethernet PHY Register Control - MR13 (EPHYREGCTL), address 0x00D ....................... 1613 Ethernet PHY Address or Data - MR14 (EPHYADDAR), address 0x00E .......................... 1615 Ethernet PHY Status - MR16 (EPHYSTS), address 0x010 .............................................. 1616 Ethernet PHY Specific Control- MR17 (EPHYSCR), address 0x011 ................................ 1619 Ethernet PHY MII Interrupt Status 1 - MR18 (EPHYMISR1), address 0x012 .................... 1622 Ethernet PHY MII Interrupt Status 2 - MR19 (EPHYMISR2), address 0x013 .................... 1625 Ethernet PHY False Carrier Sense Counter - MR20 (EPHYFCSCR), address 0x014 ........ 1628 Ethernet PHY Receive Error Count - MR21 (EPHYRXERCNT), address 0x015 ............... 1629 Ethernet PHY BIST Control - MR22 (EPHYBISTCR), address 0x016 .............................. 1630 Ethernet PHY LED Control - MR24 (EPHYLEDCR), address 0x018 ................................ 1633 Ethernet PHY Control - MR25 (EPHYCTL), address 0x019 ............................................. 1634 Ethernet PHY 10Base-T Status/Control - MR26 (EPHY10BTSC), address 0x01A ............ 1636 June 18, 2014 41 Texas Instruments-Production Data Table of Contents Register 96: Register 97: Register 98: Register 99: Register 100: Ethernet PHY BIST Control and Status 1 - MR27 (EPHYBICSR1), address 0x01B ........... 1638 Ethernet PHY BIST Control and Status 2 - MR28 (EPHYBICSR2), address 0x01C .......... 1639 Ethernet PHY Cable Diagnostic Control - MR30 (EPHYCDCR), address 0x01E ............... 1640 Ethernet PHY Reset Control - MR31 (EPHYRCR), address 0x01F .................................. 1641 Ethernet PHY LED Configuration - MR37 (EPHYLEDCFG), address 0x025 ..................... 1642 Analog Comparators ................................................................................................................. 1653 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Analog Comparator Masked Interrupt Status (ACMIS), offset 0x000 ................................ 1660 Analog Comparator Raw Interrupt Status (ACRIS), offset 0x004 ..................................... 1661 Analog Comparator Interrupt Enable (ACINTEN), offset 0x008 ....................................... 1662 Analog Comparator Reference Voltage Control (ACREFCTL), offset 0x010 ..................... 1663 Analog Comparator Status 0 (ACSTAT0), offset 0x020 ................................................... 1664 Analog Comparator Status 1 (ACSTAT1), offset 0x040 ................................................... 1664 Analog Comparator Status 2 (ACSTAT2), offset 0x060 ................................................... 1664 Analog Comparator Control 0 (ACCTL0), offset 0x024 ................................................... 1665 Analog Comparator Control 1 (ACCTL1), offset 0x044 ................................................... 1665 Analog Comparator Control 2 (ACCTL2), offset 0x064 ................................................... 1665 Analog Comparator Peripheral Properties (ACMPPP), offset 0xFC0 ................................ 1667 Pulse Width Modulator (PWM) .................................................................................................. 1669 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: Register 12: Register 13: Register 14: Register 15: Register 16: Register 17: Register 18: Register 19: Register 20: Register 21: Register 22: Register 23: Register 24: Register 25: Register 26: Register 27: Register 28: Register 29: Register 30: PWM Master Control (PWMCTL), offset 0x000 .............................................................. 1683 PWM Time Base Sync (PWMSYNC), offset 0x004 ......................................................... 1685 PWM Output Enable (PWMENABLE), offset 0x008 ........................................................ 1686 PWM Output Inversion (PWMINVERT), offset 0x00C ..................................................... 1688 PWM Output Fault (PWMFAULT), offset 0x010 .............................................................. 1690 PWM Interrupt Enable (PWMINTEN), offset 0x014 ......................................................... 1692 PWM Raw Interrupt Status (PWMRIS), offset 0x018 ...................................................... 1694 PWM Interrupt Status and Clear (PWMISC), offset 0x01C .............................................. 1697 PWM Status (PWMSTATUS), offset 0x020 .................................................................... 1700 PWM Fault Condition Value (PWMFAULTVAL), offset 0x024 ........................................... 1702 PWM Enable Update (PWMENUPD), offset 0x028 ......................................................... 1704 PWM0 Control (PWM0CTL), offset 0x040 ...................................................................... 1708 PWM1 Control (PWM1CTL), offset 0x080 ...................................................................... 1708 PWM2 Control (PWM2CTL), offset 0x0C0 ..................................................................... 1708 PWM3 Control (PWM3CTL), offset 0x100 ...................................................................... 1708 PWM0 Interrupt and Trigger Enable (PWM0INTEN), offset 0x044 ................................... 1713 PWM1 Interrupt and Trigger Enable (PWM1INTEN), offset 0x084 ................................... 1713 PWM2 Interrupt and Trigger Enable (PWM2INTEN), offset 0x0C4 ................................... 1713 PWM3 Interrupt and Trigger Enable (PWM3INTEN), offset 0x104 ................................... 1713 PWM0 Raw Interrupt Status (PWM0RIS), offset 0x048 ................................................... 1716 PWM1 Raw Interrupt Status (PWM1RIS), offset 0x088 ................................................... 1716 PWM2 Raw Interrupt Status (PWM2RIS), offset 0x0C8 .................................................. 1716 PWM3 Raw Interrupt Status (PWM3RIS), offset 0x108 ................................................... 1716 PWM0 Interrupt Status and Clear (PWM0ISC), offset 0x04C .......................................... 1718 PWM1 Interrupt Status and Clear (PWM1ISC), offset 0x08C .......................................... 1718 PWM2 Interrupt Status and Clear (PWM2ISC), offset 0x0CC .......................................... 1718 PWM3 Interrupt Status and Clear (PWM3ISC), offset 0x10C .......................................... 1718 PWM0 Load (PWM0LOAD), offset 0x050 ...................................................................... 1720 PWM1 Load (PWM1LOAD), offset 0x090 ...................................................................... 1720 PWM2 Load (PWM2LOAD), offset 0x0D0 ...................................................................... 1720 42 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 31: Register 32: Register 33: Register 34: Register 35: Register 36: Register 37: Register 38: Register 39: Register 40: Register 41: Register 42: Register 43: Register 44: Register 45: Register 46: Register 47: Register 48: Register 49: Register 50: Register 51: Register 52: Register 53: Register 54: Register 55: Register 56: Register 57: Register 58: Register 59: Register 60: Register 61: Register 62: Register 63: Register 64: Register 65: Register 66: Register 67: Register 68: Register 69: Register 70: Register 71: Register 72: Register 73: Register 74: Register 75: Register 76: Register 77: Register 78: PWM3 Load (PWM3LOAD), offset 0x110 ...................................................................... 1720 PWM0 Counter (PWM0COUNT), offset 0x054 ............................................................... 1721 PWM1 Counter (PWM1COUNT), offset 0x094 ............................................................... 1721 PWM2 Counter (PWM2COUNT), offset 0x0D4 .............................................................. 1721 PWM3 Counter (PWM3COUNT), offset 0x114 ............................................................... 1721 PWM0 Compare A (PWM0CMPA), offset 0x058 ............................................................ 1722 PWM1 Compare A (PWM1CMPA), offset 0x098 ............................................................ 1722 PWM2 Compare A (PWM2CMPA), offset 0x0D8 ............................................................ 1722 PWM3 Compare A (PWM3CMPA), offset 0x118 ............................................................. 1722 PWM0 Compare B (PWM0CMPB), offset 0x05C ............................................................ 1723 PWM1 Compare B (PWM1CMPB), offset 0x09C ............................................................ 1723 PWM2 Compare B (PWM2CMPB), offset 0x0DC ........................................................... 1723 PWM3 Compare B (PWM3CMPB), offset 0x11C ............................................................ 1723 PWM0 Generator A Control (PWM0GENA), offset 0x060 ............................................... 1724 PWM1 Generator A Control (PWM1GENA), offset 0x0A0 ............................................... 1724 PWM2 Generator A Control (PWM2GENA), offset 0x0E0 ............................................... 1724 PWM3 Generator A Control (PWM3GENA), offset 0x120 ............................................... 1724 PWM0 Generator B Control (PWM0GENB), offset 0x064 ............................................... 1727 PWM1 Generator B Control (PWM1GENB), offset 0x0A4 ............................................... 1727 PWM2 Generator B Control (PWM2GENB), offset 0x0E4 ............................................... 1727 PWM3 Generator B Control (PWM3GENB), offset 0x124 ............................................... 1727 PWM0 Dead-Band Control (PWM0DBCTL), offset 0x068 ............................................... 1730 PWM1 Dead-Band Control (PWM1DBCTL), offset 0x0A8 ............................................... 1730 PWM2 Dead-Band Control (PWM2DBCTL), offset 0x0E8 ............................................... 1730 PWM3 Dead-Band Control (PWM3DBCTL), offset 0x128 ............................................... 1730 PWM0 Dead-Band Rising-Edge Delay (PWM0DBRISE), offset 0x06C ............................ 1731 PWM1 Dead-Band Rising-Edge Delay (PWM1DBRISE), offset 0x0AC ............................ 1731 PWM2 Dead-Band Rising-Edge Delay (PWM2DBRISE), offset 0x0EC ............................ 1731 PWM3 Dead-Band Rising-Edge Delay (PWM3DBRISE), offset 0x12C ............................ 1731 PWM0 Dead-Band Falling-Edge-Delay (PWM0DBFALL), offset 0x070 ............................ 1732 PWM1 Dead-Band Falling-Edge-Delay (PWM1DBFALL), offset 0x0B0 ............................ 1732 PWM2 Dead-Band Falling-Edge-Delay (PWM2DBFALL), offset 0x0F0 ............................ 1732 PWM3 Dead-Band Falling-Edge-Delay (PWM3DBFALL), offset 0x130 ............................ 1732 PWM0 Fault Source 0 (PWM0FLTSRC0), offset 0x074 .................................................. 1733 PWM1 Fault Source 0 (PWM1FLTSRC0), offset 0x0B4 .................................................. 1733 PWM2 Fault Source 0 (PWM2FLTSRC0), offset 0x0F4 .................................................. 1733 PWM3 Fault Source 0 (PWM3FLTSRC0), offset 0x134 .................................................. 1733 PWM0 Fault Source 1 (PWM0FLTSRC1), offset 0x078 .................................................. 1735 PWM1 Fault Source 1 (PWM1FLTSRC1), offset 0x0B8 .................................................. 1735 PWM2 Fault Source 1 (PWM2FLTSRC1), offset 0x0F8 .................................................. 1735 PWM3 Fault Source 1 (PWM3FLTSRC1), offset 0x138 .................................................. 1735 PWM0 Minimum Fault Period (PWM0MINFLTPER), offset 0x07C ................................... 1738 PWM1 Minimum Fault Period (PWM1MINFLTPER), offset 0x0BC ................................... 1738 PWM2 Minimum Fault Period (PWM2MINFLTPER), offset 0x0FC ................................... 1738 PWM3 Minimum Fault Period (PWM3MINFLTPER), offset 0x13C ................................... 1738 PWM0 Fault Pin Logic Sense (PWM0FLTSEN), offset 0x800 .......................................... 1739 PWM1 Fault Pin Logic Sense (PWM1FLTSEN), offset 0x880 .......................................... 1739 PWM2 Fault Pin Logic Sense (PWM2FLTSEN), offset 0x900 .......................................... 1739 June 18, 2014 43 Texas Instruments-Production Data Table of Contents Register 79: Register 80: Register 81: Register 82: Register 83: Register 84: Register 85: Register 86: Register 87: Register 88: Register 89: PWM3 Fault Pin Logic Sense (PWM3FLTSEN), offset 0x980 .......................................... 1739 PWM0 Fault Status 0 (PWM0FLTSTAT0), offset 0x804 ................................................... 1740 PWM1 Fault Status 0 (PWM1FLTSTAT0), offset 0x884 ................................................... 1740 PWM2 Fault Status 0 (PWM2FLTSTAT0), offset 0x904 ................................................... 1740 PWM3 Fault Status 0 (PWM3FLTSTAT0), offset 0x984 ................................................... 1740 PWM0 Fault Status 1 (PWM0FLTSTAT1), offset 0x808 ................................................... 1742 PWM1 Fault Status 1 (PWM1FLTSTAT1), offset 0x888 ................................................... 1742 PWM2 Fault Status 1 (PWM2FLTSTAT1), offset 0x908 ................................................... 1742 PWM3 Fault Status 1 (PWM3FLTSTAT1), offset 0x988 ................................................... 1742 PWM Peripheral Properties (PWMPP), offset 0xFC0 ...................................................... 1745 PWM Clock Configuration (PWMCC), offset 0xFC8 ........................................................ 1747 Quadrature Encoder Interface (QEI) ........................................................................................ 1748 Register 1: Register 2: Register 3: Register 4: Register 5: Register 6: Register 7: Register 8: Register 9: Register 10: Register 11: QEI Control (QEICTL), offset 0x000 .............................................................................. QEI Status (QEISTAT), offset 0x004 .............................................................................. QEI Position (QEIPOS), offset 0x008 ............................................................................ QEI Maximum Position (QEIMAXPOS), offset 0x00C ..................................................... QEI Timer Load (QEILOAD), offset 0x010 ..................................................................... QEI Timer (QEITIME), offset 0x014 ............................................................................... QEI Velocity Counter (QEICOUNT), offset 0x018 ........................................................... QEI Velocity (QEISPEED), offset 0x01C ........................................................................ QEI Interrupt Enable (QEIINTEN), offset 0x020 ............................................................. QEI Raw Interrupt Status (QEIRIS), offset 0x024 ........................................................... QEI Interrupt Status and Clear (QEIISC), offset 0x028 ................................................... 44 1755 1758 1759 1760 1761 1762 1763 1764 1765 1767 1769 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Revision History The revision history table notes changes made between the indicated revisions of the TM4C1294NCPDT data sheet. Table 1. Revision History Date June 2014 April 2014 Revision Description 15863.2743 ■ In ADC chapter, clarified section "Sample and Hold Window Control". ■ In SSI chapter: – Noted that during idle periods the transmit data line SSInTx is tristated. – Added clarification to uDMA section about wait states. ■ In Ethernet chapter: – Corrected functional description of DMA descriptors. – Added description of Receive Checksum Offload Engine. ■ In Electrical Characteristics chapter: – In "Power and Brown-Out Levels" table, updated VPOR with characterized values. – In "PIOSC Clock Characteristics" table, clarified FPIOSC values. – In "Low-Frequency Internal Oscillator Characteristics" table, updated FLFIOSC with characterized values. – In "Main Oscillator Input Characteristics" table, removed Pending Characterization footnote. – In "ADC Electrical Characteristics for ADC at 1 Msps" table, updated Max value for VINCM. – In "ADC Electrical Characteristics for ADC at 2 Msps" table, updated values for VINCM, RS, fCONV, TS, TLT, and the Dynamic Characteristics. – In "Current Consumption" table, updated values that were pending. ■ In Package Information appendix: – Moved Orderable Part Numbers table to addendum. – Deleted Packaging Materials section and put into separate packaging document. ■ Additional minor data sheet clarifications and corrections. 15802.2729 ■ In the System Control chapter: – Clarified Hibernation Module reset section. – Added clarifications in Deep-Sleep Mode section. – Added reset for DID1 register. – Corrected description for RESC register, and changed bit 6 HIB Reset to reserved. – Added note to DSSYSDIV bit in DSCLKCFG register that values 0x0 and 0x1 should not be used. – Added clarification to FLASHPM bit in DSLPPWRCFG register when using the LFIOSC as the Deep-Sleep clock source. – Added four registers, UNIQUEIDn, which combined provide a 128-bit unique identifier for each device. ■ In the Hibernation chapter, added clarification to Hibernation Control (HIBCTL) register about External Wake and Interrupt Pin Enable bit. ■ In the Internal Memory chapter, added information on soft reset handling to the EEPROM section. ■ In the GPIO chapter: – Replaced table GPIO Pins With Non-Zero Reset Values with table GPIO Pins With Special Considerations. – Added note about preventing false interrupts. ■ In the Timer chapter, clarified behavior of TnMIE and TnCINTD bits in the GPTM Timer n Mode (GPTMTnMR) registers. ■ In the ADC chapter: – Corrected ADC maximum sample rate to two million samples/second. June 18, 2014 45 Texas Instruments-Production Data Revision History Table 1. Revision History (continued) Date Revision Description – – December 2013 Corrected figure ADC Input Equivalency. Removed Dither Enable bit and corrected reset for ADCCTL register. ■ In the UART chapter, clarified that for a receive timeout, the RTIM bit in the UARTIM register must be set to see the RTMIS and RTRIS status in the UARTMIS and UARTRIS registers. ■ In the SSI chapter: – Clarified Receive FIFO operation. – Clarified DMA operation. – Removed End of Transmission (EOT) bit 4 from QSSI Control 1 (SSICR1) register. ■ In the Ethernet chapter, clarified Initialization and Configuration. ■ In the USB chapter, added important note that when configured as a bus-powered Device, the USB can operate in SUSPEND mode but produces a higher power draw than required to be compliant. ■ In the Electrical Characteristics chapter: – In Reset Characteristics table, updated internal reset time parameter values. – In PIOSC Clock Characteristics table, updated parameter values. – In Hibernation External Oscillator (XOSC) Input Characteristics table, removed parameter C0 Crystal shunt capacitance. – Updated Crystal Parameters table. – In Hibernation Module Tamper I/O Characteristics table, updated TMPRn pull-up resistor parameter values. – In Flash Memory Characteristics table, updated TPROG64 nom value. – In EEPROM Characteristics table, added values for Read access time and removed EEPROM recovery Power-On Reset delay parameter. – In EPI PSRAM Interface Characteristics table, updated Min value for EPI_CLK period. – In ADC Electrical Characteristics at 1 Msps table, updated values for VADCIN parameter. – Corrected ADC Input Equivalency diagram. – In Bi- and Quad-SSI Characteristics table, added clarifying footnotes. – Added PWM Timing Characteristics table. – Updated Current Consumption table. – In Peripheral Current Consumption table, updated IDDEMAC Nom value. ■ In Package Information appendix: – Updated Orderable Devices section to reflect silicon revision 3 part numbers. – Added Device Nomenclature section. – Deleted packaging materials section and put into separate document. ■ Additional minor data sheet clarifications and corrections. 15638.2711 ■ Changed NDA (Non-Disclosure Agreement) footer to indicate NDA only applies to USB content. ■ In System Control chapter: – Added sections "Optional Clock Output Signal (DIVSCLK)" and "Hardware System Service Request". – Removed some registers and bits: • LDORDRIS bit from Raw Interrupt Status (RIS) register, LDORDIM bit from Interrupt Mask Control (IMC) register, and LDORDMIS bit from Masked Interrupt Status and Clear (MISC) register • Deep Sleep Mode Memory Timing Register 0 for Main Flash and EEPROM (DSMEMTIM0) register • LDO Power Calibration (LDOPCAL) register • LDO Sleep Power Control (LDOSPCTL) register • LMINERR bit from Sleep/Deep-Sleep Power Mode Status (SDPMST) register – Added LDOSME, TSPDE, PIOSCPDE, SRAMSM, SRAMLPM, FLASHLPM, and LDOSEQ bits in SYSPROP register. ■ In Internal Memory chapter: 46 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 1. Revision History (continued) Date Revision Description – – – – October 2013 Added subsections to "Flash Memory" section about Execute-Only Protection, Read-Only Protection and Permanently Disabling Debug. Removed INVPL bit from EEPROM Done Status (EEDONE) register. Updated table "MEMTIM0 Register Configuration vs. Frequency" with lower wait states, and improved performance values. Added EEPROM initialization code to "EEPROM Initialization and Configuration" section. ■ In the ADC chapter: – Added section "Sample and Hold Window Control" and clarified section "Sample Phase Control". – Clarified description of ADC Sample Phase Control (ADCSPC) register. ■ Updated Electrical Characteristics chapter based on characterization information received. ■ Additional minor data sheet clarifications and corrections. 15440.2698 Initial release of NDA data sheet. June 18, 2014 47 Texas Instruments-Production Data About This Document About This Document This data sheet provides reference information for the TM4C1294NCPDT microcontroller, describing the functional blocks of the system-on-chip (SoC) device designed around the ARM® Cortex™-M4F core. Audience This manual is intended for system software developers, hardware designers, and application developers. About This Manual This document is organized into sections that correspond to each major feature. Related Documents The following related documents are available on the Tiva™ C Series web site at http://www.ti.com/tiva-c: ■ Tiva™ C Series TM4C129x Silicon Errata (literature number SPMZ850) ■ TivaWare™ Boot Loader for C Series User's Guide (literature number SPMU301) ■ TivaWare™ Graphics Library for C Series User's Guide (literature number SPMU300) ■ TivaWare™ for C Series Release Notes (literature number SPMU299) ■ TivaWare™ Peripheral Driver Library for C Series User's Guide (literature number SPMU298) ■ TivaWare™ USB Library for C Series User's Guide (literature number SPMU297) ■ Tiva™ C Series TM4C129x ROM User’s Guide (literature number SPMU363) The following related documents may also be useful: ■ ARM® Cortex™-M4 Errata (literature number SPMZ637) ■ ARM® Cortex™-M4 Technical Reference Manual ■ ARM® Debug Interface V5 Architecture Specification ■ ARM® Embedded Trace Macrocell Architecture Specification ■ Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) ■ IEEE Standard 1149.1-Test Access Port and Boundary-Scan Architecture This documentation list was current as of publication date. Please check the web site for additional documentation, including application notes and white papers. 48 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Documentation Conventions This document uses the conventions shown in Table 2 on page 49. Table 2. Documentation Conventions Notation Meaning General Register Notation REGISTER APB registers are indicated in uppercase bold. For example, PBORCTL is the Power-On and Brown-Out Reset Control register. If a register name contains a lowercase n, it represents more than one register. For example, SRCRn represents any (or all) of the three Software Reset Control registers: SRCR0, SRCR1 , and SRCR2. bit A single bit in a register. bit field Two or more consecutive and related bits. offset 0xnnn A hexadecimal increment to a register's address, relative to that module's base address as specified in Table 2-4 on page 103. Register N Registers are numbered consecutively throughout the document to aid in referencing them. The register number has no meaning to software. reserved Register bits marked reserved are reserved for future use. In most cases, reserved bits are set to 0; however, user software should not rely on the value of a reserved bit. To provide software compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. yy:xx The range of register bits inclusive from xx to yy. For example, 31:15 means bits 15 through 31 in that register. Register Bit/Field Types This value in the register bit diagram indicates whether software running on the controller can change the value of the bit field. RC Software can read this field. The bit or field is cleared by hardware after reading the bit/field. RO Software can read this field. Always write the chip reset value. RW Software can read or write this field. RWC Software can read or write this field. Writing to it with any value clears the register. RW1C Software can read or write this field. A write of a 0 to a W1C bit does not affect the bit value in the register. A write of a 1 clears the value of the bit in the register; the remaining bits remain unchanged. This register type is primarily used for clearing interrupt status bits where the read operation provides the interrupt status and the write of the read value clears only the interrupts being reported at the time the register was read. RW1S Software can read or write a 1 to this field. A write of a 0 to a RW1S bit does not affect the bit value in the register. W1C Software can write this field. A write of a 0 to a W1C bit does not affect the bit value in the register. A write of a 1 clears the value of the bit in the register; the remaining bits remain unchanged. A read of the register returns no meaningful data. This register is typically used to clear the corresponding bit in an interrupt register. WO Only a write by software is valid; a read of the register returns no meaningful data. Register Bit/Field Reset Value This value in the register bit diagram shows the bit/field value after any reset, unless noted. 0 Bit cleared to 0 on chip reset. 1 Bit set to 1 on chip reset. - Nondeterministic. Pin/Signal Notation [] Pin alternate function; a pin defaults to the signal without the brackets. pin Refers to the physical connection on the package. signal Refers to the electrical signal encoding of a pin. June 18, 2014 49 Texas Instruments-Production Data About This Document Table 2. Documentation Conventions (continued) Notation Meaning assert a signal Change the value of the signal from the logically False state to the logically True state. For active High signals, the asserted signal value is 1 (High); for active Low signals, the asserted signal value is 0 (Low). The active polarity (High or Low) is defined by the signal name (see SIGNAL and SIGNAL below). deassert a signal Change the value of the signal from the logically True state to the logically False state. SIGNAL Signal names are in uppercase and in the Courier font. An overbar on a signal name indicates that it is active Low. To assert SIGNAL is to drive it Low; to deassert SIGNAL is to drive it High. SIGNAL Signal names are in uppercase and in the Courier font. An active High signal has no overbar. To assert SIGNAL is to drive it High; to deassert SIGNAL is to drive it Low. Numbers X An uppercase X indicates any of several values is allowed, where X can be any legal pattern. For example, a binary value of 0X00 can be either 0100 or 0000, a hex value of 0xX is 0x0 or 0x1, and so on. 0x Hexadecimal numbers have a prefix of 0x. For example, 0x00FF is the hexadecimal number FF. All other numbers within register tables are assumed to be binary. Within conceptual information, binary numbers are indicated with a b suffix, for example, 1011b, and decimal numbers are written without a prefix or suffix. 50 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1 Architectural Overview ® Texas Instrument's Tiva™ C Series microcontrollers provide designers a high-performance ARM Cortex™-M-based architecture with a broad set of integration capabilities and a strong ecosystem of software and development tools. Targeting performance and flexibility, the Tiva™ C Series architecture offers a 120 MHz Cortex-M with FPU, a variety of integrated memories and multiple programmable GPIO. Tiva™ C Series devices offer consumers compelling cost-effective solutions by integrating application-specific peripherals and providing a comprehensive library of software tools which minimize board costs and design-cycle time. Offering quicker time-to-market and cost savings, the Tiva™ C Series microcontrollers are the leading choice in high-performance 32-bit applications. This chapter contains an overview of the Tiva™ C Series microcontrollers as well as details on the TM4C1294NCPDT microcontroller: ■ ■ ■ ■ ■ ■ 1.1 “Tiva™ C Series Overview” on page 51 “TM4C1294NCPDT Microcontroller Overview” on page 52 “TM4C1294NCPDT Microcontroller Features” on page 55 “TM4C1294NCPDT Microcontroller Hardware Details” on page 78 “Kits” on page 79 “Support Information” on page 79 Tiva™ C Series Overview The Tiva™ C Series ARM Cortex-M4 microcontrollers provide top performance and advanced integration. The product family is positioned for cost-effective applications requiring significant control processing and connectivity capabilities such as: ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Industrial communication equipment Network appliances, gateways & adapters Residential & commercial site monitoring & control Remote connectivity & monitoring Security/access systems HMI control panels Factory automation control Test and measurement equipment Fire & security systems Motion control & power inversion Medical instrumentation Gaming equipment Electronic point-of-sale (POS) displays Smart Energy/Smart Grid solutions Intelligent lighting control Vehicle tracking Tiva™ C Series microcontrollers integrate a large variety of rich communication features to enable a new class of highly connected designs with the ability to allow critical, real-time control between performance and power. The microcontrollers feature integrated communication peripherals along with other high-performance analog and digital functions to offer a strong foundation for many different target uses, spanning from human machine interface to networked system management controllers. June 18, 2014 51 Texas Instruments-Production Data Architectural Overview In addition, Tiva™ C Series microcontrollers offer the advantages of ARM's widely available development tools, System-on-Chip (SoC) infrastructure, and a large user community. Additionally, these microcontrollers use ARM's Thumb®-compatible Thumb-2 instruction set to reduce memory requirements and, thereby, cost. Finally, the TM4C1294NCPDT microcontroller is code-compatible to all members of the extensive Tiva™ C Series, providing flexibility to fit precise needs. Texas Instruments offers a complete solution to get to market quickly, with evaluation and development boards, white papers and application notes, an easy-to-use peripheral driver library, and a strong support, sales, and distributor network. 1.2 TM4C1294NCPDT Microcontroller Overview The TM4C1294NCPDT microcontroller combines complex integration and high performance with the features shown in Table 1-1. Table 1-1. TM4C1294NCPDT Microcontroller Features Feature Description Performance Core ARM Cortex-M4F processor core Performance 120-MHz operation; 150 DMIPS performance Flash 1024 KB Flash memory System SRAM 256 KB single-cycle System SRAM EEPROM 6KB of EEPROM Internal ROM Internal ROM loaded with TivaWare™ for C Series software External Peripheral Interface (EPI) 8-/16-/32- bit dedicated interface for peripherals and memory Security Cyclical Redundancy Check (CRC) Hardware 16-/32-bit Hash function that supports four CRC forms Tamper Support for four tamper inputs and configurable tamper event response Communication Interfaces Universal Asynchronous Receivers/Transmitter (UART) Eight UARTs Quad Synchronous Serial Interface (QSSI) Four SSI modules with Bi-, Quad- and advanced SSI support Inter-Integrated Circuit (I2C) Ten I2C modules with four transmission speeds including high-speed mode Controller Area Network (CAN) Two CAN 2.0 A/B controllers Ethernet MAC 10/100 Ethernet MAC Ethernet PHY PHY with IEEE 1588 PTP hardware support Universal Serial Bus (USB) USB 2.0 OTG/Host/Device with ULPI interface option and Link Power Management (LPM) support System Integration Micro Direct Memory Access (µDMA) ARM® PrimeCell® 32-channel configurable μDMA controller General-Purpose Timer (GPTM) Eight 16/32-bit GPTM blocks Watchdog Timer (WDT) Two watchdog timers Hibernation Module (HIB) Low-power battery-backed Hibernation module General-Purpose Input/Output (GPIO) 15 physical GPIO blocks Advanced Motion Control Pulse Width Modulator (PWM) One PWM module, with four PWM generator blocks and a control block, for a total of 8 PWM outputs. 52 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 1-1. TM4C1294NCPDT Microcontroller Features (continued) Feature Description Quadrature Encoder Interface (QEI) One QEI module Analog Support Analog-to-Digital Converter (ADC) Two 12-bit ADC modules, each with a maximum sample rate of two million samples/second Analog Comparator Controller Three independent integrated analog comparators Digital Comparator 16 digital comparators JTAG and Serial Wire Debug (SWD) One JTAG module with integrated ARM SWD Package Information Package 128-pin TQFP Operating Range (Ambient) Industrial (-40°C to 85°C) temperature range Extended (-40°C to 105°C) temperature range Figure 1-1 on page 54 shows the features on the TM4C1294NCPDT microcontroller. Note that there are two on-chip buses that connect the core to the peripherals. The Advanced Peripheral Bus (APB) bus is the legacy bus. The Advanced High-Performance Bus (AHB) bus provides better back-to-back access performance than the APB bus. June 18, 2014 53 Texas Instruments-Production Data Architectural Overview Figure 1-1. Tiva™ TM4C1294NCPDT Microcontroller High-Level Block Diagram JTAG/SWD ARM® Cortex™-M4F ROM (120MHz) System Control and Clocks (w/ Precis. Osc.) ETM FPU NVIC MPU DCode bus Boot Loader DriverLib AES & CRC Ethernet Boot Loader Flash (1024KB) ICode bus System Bus TM4C1294NCPDT Bus Matrix SRAM (256KB) SYSTEM PERIPHERALS Watchdog Timer (2 Units) DMA Hibernation Module EEPROM (6K) Tamper CRC Module External Peripheral Interface USB OTG (FS PHY or ULPI) SSI (4 Units) Ethernet MAC/PHY Advanced Peripheral Bus (APB) GeneralPurpose Timer (8 Units) Advanced High-Performance Bus (AHB) GPIOs (90) SERIAL PERIPHERALS UART (8 Units) I2C (10 Units) CAN Controller (2 Units) ANALOG PERIPHERALS Analog Comparator (3 Units) 12- Bit ADC (2 Units / 20 Channels) MOTION CONTROL PERIPHERALS PWM (1 Units / 8 Signals) QEI (1 Units) 54 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1.3 TM4C1294NCPDT Microcontroller Features The TM4C1294NCPDT microcontroller component features and general function are discussed in more detail in the following section. 1.3.1 ARM Cortex-M4F Processor Core All members of the Tiva™ C Series, including the TM4C1294NCPDT microcontroller, are designed around an ARM Cortex-M processor core. The ARM Cortex-M processor provides the core for a high-performance, low-cost platform that meets the needs of minimal memory implementation, reduced pin count, and low power consumption, while delivering outstanding computational performance and exceptional system response to interrupts. 1.3.1.1 Processor Core (see page 80) ■ 32-bit ARM Cortex-M4F architecture optimized for small-footprint embedded applications ■ 120-MHz operation; 150 DMIPS performance ■ Outstanding processing performance combined with fast interrupt handling ■ Thumb-2 mixed 16-/32-bit instruction set delivers the high performance expected of a 32-bit ARM core in a compact memory size usually associated with 8- and 16-bit devices, typically in the range of a few kilobytes of memory for microcontroller-class applications – Single-cycle multiply instruction and hardware divide – Atomic bit manipulation (bit-banding), delivering maximum memory utilization and streamlined peripheral control – Unaligned data access, enabling data to be efficiently packed into memory ■ IEEE754-compliant single-precision Floating-Point Unit (FPU) ■ 16-bit SIMD vector processing unit ■ Fast code execution permits slower processor clock or increases sleep mode time ■ Harvard architecture characterized by separate buses for instruction and data ■ Efficient processor core, system and memories ■ Hardware division and fast digital-signal-processing orientated multiply accumulate ■ Saturating arithmetic for signal processing ■ Deterministic, high-performance interrupt handling for time-critical applications ■ Memory protection unit (MPU) to provide a privileged mode for protected operating system functionality ■ Enhanced system debug with extensive breakpoint and trace capabilities ■ Serial Wire Debug and Serial Wire Trace reduce the number of pins required for debugging and tracing June 18, 2014 55 Texas Instruments-Production Data Architectural Overview ■ Migration from the ARM7™ processor family for better performance and power efficiency ■ Optimized for single-cycle Flash memory usage up to specific frequencies; see “Internal Memory” on page 600 for more information. ■ Ultra-low power consumption with integrated sleep modes 1.3.1.2 System Timer (SysTick) (see page 135) ARM Cortex-M4F includes an integrated system timer, SysTick. SysTick provides a simple, 24-bit, clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. The counter can be used in several different ways, for example: ■ An RTOS tick timer that fires at a programmable rate (for example, 100 Hz) and invokes a SysTick routine ■ A high-speed alarm timer using the system clock ■ A variable rate alarm or signal timer—the duration is range-dependent on the reference clock used and the dynamic range of the counter ■ A simple counter used to measure time to completion and time used ■ An internal clock-source control based on missing/meeting durations 1.3.1.3 Nested Vectored Interrupt Controller (NVIC) (see page 136) The TM4C1294NCPDT controller includes the ARM Nested Vectored Interrupt Controller (NVIC). The NVIC and Cortex-M4F prioritize and handle all exceptions in Handler Mode. The processor state is automatically stored to the stack on an exception and automatically restored from the stack at the end of the Interrupt Service Routine (ISR). The interrupt vector is fetched in parallel to the state saving, enabling efficient interrupt entry. The processor supports tail-chaining, meaning that back-to-back interrupts can be performed without the overhead of state saving and restoration. Software can set eight priority levels on 7 exceptions (system handlers) and 106 interrupts. ■ Deterministic, fast interrupt processing: always 12 cycles, or just 6 cycles with tail-chaining (these values reflect no FPU stacking) ■ External non-maskable interrupt signal (NMI) available for immediate execution of NMI handler for safety critical applications ■ Dynamically reprioritizable interrupts ■ Exceptional interrupt handling via hardware implementation of required register manipulations 1.3.1.4 System Control Block (SCB) (see page 137) The SCB provides system implementation information and system control, including configuration, control, and reporting of system exceptions. 1.3.1.5 Memory Protection Unit (MPU) (see page 137) The MPU supports the standard ARM7 Protected Memory System Architecture (PMSA) model. The MPU provides full support for protection regions, overlapping protection regions, access permissions, and exporting memory attributes to the system. 56 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1.3.1.6 Floating-Point Unit (FPU) (see page 142) The FPU fully supports single-precision add, subtract, multiply, divide, multiply and accumulate, and square root operations. It also provides conversions between fixed-point and floating-point data formats, and floating-point constant instructions. ■ 32-bit instructions for single-precision (C float) data-processing operations ■ Combined multiply and accumulate instructions for increased precision (Fused MAC) ■ Hardware support for conversion, addition, subtraction, multiplication with optional accumulate, division, and square-root ■ Hardware support for denormals and all IEEE rounding modes ■ 32 dedicated 32-bit single-precision registers, also addressable as 16 double-word registers ■ Decoupled three stage pipeline 1.3.2 On-Chip Memory The TM4C1294NCPDT microcontroller is integrated with the following set of on-chip memory and features: ■ 256 KB single-cycle SRAM ■ 1024 KB Flash memory ■ 6KB EEPROM ■ Internal ROM loaded with TivaWare™ for C Series software: – TivaWare™ Peripheral Driver Library – TivaWare Boot Loader – Advanced Encryption Standard (AES) cryptography tables – Cyclic Redundancy Check (CRC) error detection functionality 1.3.2.1 SRAM (see page 602) The TM4C1294NCPDT microcontroller provides 256 KB of single-cycle on-chip SRAM. The internal SRAM of the device is located at offset 0x2000.0000 of the device memory map. The SRAM is implemented using four 32-bit wide interleaving SRAM banks (separate SRAM arrays) which allow for increased speed between memory accesses. The SRAM memory provides nearly 2 GB/s memory bandwidth at a 120 MHz clock frequency. Because read-modify-write (RMW) operations are very time consuming, ARM has introduced bit-banding technology in the Cortex-M4F processor. With a bit-band-enabled processor, certain regions in the memory map (SRAM and peripheral space) can use address aliases to access individual bits in a single, atomic operation. Data can be transferred to and from SRAM by the following masters: ■ µDMA ■ USB ■ Ethernet Controller June 18, 2014 57 Texas Instruments-Production Data Architectural Overview 1.3.2.2 Flash Memory (see page 604) The TM4C1294NCPDT microcontroller provides 1024 KB of on-chip Flash memory. The Flash memory is configured as four banks of 16K x 128 bits (4 * 256 KB total) which are two-way interleaved. Memory blocks can be marked as read-only or execute-only, providing different levels of code protection. Read-only blocks cannot be erased or programmed, protecting the contents of those blocks from being modified. Execute-only blocks cannot be erased or programmed, and can only be read by the controller instruction fetch mechanism, protecting the contents of those blocks from being read by either the controller or by a debugger. The TM4C1294NCPDT microcontroller provides enhanced performance and power savings by implementation of two sets of instruction prefetch buffers. Each prefetch buffer is 2 x 256 bits and can be combined as a 4 x 256-bit prefetch buffer. The Flash can also be accessed by the µDMA in Run Mode. 1.3.2.3 ROM (see page 602) The TM4C1294NCPDT ROM is preprogrammed with the following software and programs: ■ TivaWare Peripheral Driver Library ■ TivaWare Boot Loader ■ Advanced Encryption Standard (AES) cryptography tables ■ Cyclic Redundancy Check (CRC) error-detection functionality The TivaWare Peripheral Driver Library is a royalty-free software library for controlling on-chip peripherals with a boot-loader capability. The library performs both peripheral initialization and control functions, with a choice of polled or interrupt-driven peripheral support. In addition, the library is designed to take full advantage of the stellar interrupt performance of the ARM Cortex-M4F core. No special pragmas or custom assembly code prologue/epilogue functions are required. For applications that require in-field programmability, the royalty-free TivaWare Boot Loader can act as an application loader and support in-field firmware updates. The Advanced Encryption Standard (AES) is a publicly defined encryption standard used by the U.S. Government. AES is a strong encryption method with reasonable performance and size. In addition, it is fast in both hardware and software, is fairly easy to implement, and requires little memory. The Texas Instruments encryption package is available with full source code, and is based on Lesser General Public License (LGPL) source. An LGPL means that the code can be used within an application without any copyleft implications for the application (the code does not automatically become open source). Modifications to the package source, however, must be open source. CRC (Cyclic Redundancy Check) is a technique to validate a span of data has the same contents as when previously checked. This technique can be used to validate correct receipt of messages (nothing lost or modified in transit), to validate data after decompression, to validate that Flash memory contents have not been changed, and for other cases where the data needs to be validated. A CRC is preferred over a simple checksum (for example, XOR all bits) because it catches changes more readily. Note: CRC software program are available in the TivaWare™ for C Series software for backward-compatibility. A device that has enhanced CRC integrated module should utilize this hardware for best performance. Please refer to “Cyclical Redundancy Check (CRC)” on page 946 for more information. 58 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1.3.2.4 EEPROM (see page 615) The TM4C1294NCPDT microcontroller includes an EEPROM with the following features: ■ 6Kbytes of memory accessible as 1536 32-bit words ■ 96 blocks of 16 words (64 bytes) each ■ Built-in wear leveling ■ Access protection per block ■ Lock protection option for the whole peripheral as well as per block using 32-bit to 96-bit unlock codes (application selectable) ■ Interrupt support for write completion to avoid polling ■ Endurance of 500K writes (when writing at fixed offset in every alternate page in circular fashion) to 15M operations (when cycling through two pages ) per each 2-page block. 1.3.3 External Peripheral Interface (see page 815) The External Peripheral Interface (EPI) provides access to external devices using a parallel path. Unlike communications peripherals such as SSI, UART, and I2C, the EPI is designed to act like a bus to external peripherals and memory. The EPI has the following features: ■ 8/16/32-bit dedicated parallel bus for external peripherals and memory ■ Memory interface supports contiguous memory access independent of data bus width, thus enabling code execution directly from SDRAM, SRAM and Flash memory ■ Blocking and non-blocking reads ■ Separates processor from timing details through use of an internal write FIFO ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for read and write – Read channel request asserted by programmable levels on the internal Non-Blocking Read FIFO (NBRFIFO) – Write channel request asserted by empty on the internal Write FIFO (WFIFO) The EPI supports three primary functional modes: Synchronous Dynamic Random Access Memory (SDRAM) mode, Traditional Host-Bus mode, and General-Purpose mode. The EPI module also provides custom GPIOs; however, unlike regular GPIOs, the EPI module uses a FIFO in the same way as a communication mechanism and is speed-controlled using clocking. ■ Synchronous Dynamic Random Access Memory (SDRAM) mode – Supports x16 (single data rate) SDRAM at up to 60 MHz – Supports low-cost SDRAMs up to 64 MB (512 megabits) June 18, 2014 59 Texas Instruments-Production Data Architectural Overview – Includes automatic refresh and access to all banks/rows – Includes a Sleep/Standby mode to keep contents active with minimal power draw – Multiplexed address/data interface for reduced pin count ■ Host-Bus mode – Traditional x8 and x16 MCU bus interface capabilities – Similar device compatibility options as PIC, ATmega, 8051, and others – Access to SRAM, NOR Flash memory, and other devices, with up to 1 MB of addressing in non-multiplexed mode and 256 MB in multiplexed mode (512 MB in Host-Bus 16 mode with no byte selects) – Support for up to 512 Mb PSRAM in quad chip select mode, with dedicated configuration register read and write enable. – Support of both muxed and de-muxed address and data – Access to a range of devices supporting the non-address FIFO x8 and x16 interface variant, with support for external FIFO (XFIFO) EMPTY and FULL signals – Speed controlled, with read and write data wait-state counters – Support for read/write burst mode to Host Bus – Multiple chip select modes including single, dual, and quad chip selects, with and without ALE – External iRDY signal provided for stall capability of reads and writes – Manual chip-enable (or use extra address pins) ■ General-Purpose mode – Wide parallel interfaces for fast communications with CPLDs and FPGAs – Data widths up to 32 bits – Data rates up to 150 MB/second – Optional "address" sizes from 4 bits to 20 bits – Optional clock output, read/write strobes, framing (with counter-based size), and clock-enable input ■ General parallel GPIO – 1 to 32 bits, FIFOed with speed control – Useful for custom peripherals or for digital data acquisition and actuator controls 60 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1.3.4 Cyclical Redundancy Check (CRC) (see page 946) The TM4C1294NCPDT microcontroller includes a CRC computation module for uses such as message transfer and safety system checks. The CRC has the following features: ■ Support four major CRC forms: – CRC16-CCITT as used by CCITT/ITU X.25 – CRC16-IBM as used by USB and ANSI – CRC32-IEEE as used by IEEE802.3 and MPEG2 – CRC32C as used by G.Hn ■ Allows word and byte feed ■ Supports auto-initialization and manual initialization ■ Supports MSb and LSb ■ Supports CCITT post-processing ■ Can be fed by µDMA, Flash memory and code 1.3.5 Serial Communications Peripherals The TM4C1294NCPDT controller supports both asynchronous and synchronous serial communications with: ■ 10/100 Ethernet MAC with Advanced IEEE 1588 PTP hardware and both Media Independent Interface (MII) and Reduced MII (RMII) support; integrated PHY provided ■ Two CAN 2.0 A/B controllers ■ USB 2.0 Controller OTG/Host/Device with optional high speed using external PHY through ULPI interface ■ Eight UARTs with IrDA, 9-bit and ISO 7816 support. ■ Ten I2C modules with four transmission speeds including high-speed mode ■ Four Quad Synchronous Serial Interface modules (QSSI) with bi- and quad-SSI support The following sections provide more detail on each of these communications functions. 1.3.5.1 Ethernet MAC and PHY (see page 1407) The TM4C1294NCPDT Ethernet Controller consists of a fully integrated media access controller (MAC) and network physical (PHY) interface with the following features: ■ Conforms to the IEEE 802.3 specification – 10BASE-T/100BASE-TX IEEE-802.3 compliant – Supports 10/100 Mbps data transmission rates June 18, 2014 61 Texas Instruments-Production Data Architectural Overview – Supports full-duplex and half-duplex (CSMA/CD) operation – Supports flow control and back pressure – Full-featured and enhanced auto-negotiation – Supports IEEE 802.1Q VLAN tag detection ■ Conforms to IEEE 1588-2002 Timestamp Precision Time Protocol (PTP) protocol and the IEEE 1588-2008 Advanced Timestamp specification – Transmit and Receive frame time stamping – Precision Time Protocol – Flexible pulse per second output – Supports coarse and fine correction methods ■ Multiple addressing modes – Four MAC address filters – Programmable 64-bit Hash Filter for multicast address filtering – Promiscuous mode support ■ Processor offloading – Programmable insertion (TX) or deletion (RX) of preamble and start-of-frame data – Programmable generation (TX) or deletion (RX) of CRC and pad data – IP header and hardware checksum checking (IPv4, IPv6, TCP/UDP/ICMP) ■ Highly configurable – LED activity selection – Supports network statistics with RMON/MIB counters – Supports Magic Packet and wakeup frames ■ Efficient transfers using integrated Direct Memory Access (DMA) – Dual-buffer (ring) or linked-list (chained) descriptors – Round-robin or fixed priority arbitration between TX/RX – Descriptors support up to 8 kB transfer blocks size – Programmable interrupts for flexible system implementation ■ Physical media manipulation – MDI/MDI-X cross-over support 62 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller – Register-programmable transmit amplitude – Automatic polarity correction and 10BASE-T signal reception 1.3.5.2 Controller Area Network (CAN) (see page 1356) Controller Area Network (CAN) is a multicast shared serial-bus standard for connecting electronic control units (ECUs). CAN was specifically designed to be robust in electromagnetically noisy environments and can utilize a differential balanced line like RS-485 or twisted-pair wire. Originally created for automotive purposes, it is now used in many embedded control applications (for example, industrial or medical). Bit rates up to 1 Mbps are possible at network lengths below 40 meters. Decreased bit rates allow longer network distances (for example, 125 Kbps at 500m). A transmitter sends a message to all CAN nodes (broadcasting). Each node decides on the basis of the identifier received whether it should process the message. The identifier also determines the priority that the message enjoys in competition for bus access. Each CAN message can transmit from 0 to 8 bytes of user information. The TM4C1294NCPDT microcontroller includes two CAN units with the following features: ■ CAN protocol version 2.0 part A/B ■ Bit rates up to 1 Mbps ■ 32 message objects with individual identifier masks ■ Maskable interrupt ■ Disable Automatic Retransmission mode for Time-Triggered CAN (TTCAN) applications ■ Programmable loopback mode for self-test operation ■ Programmable FIFO mode enables storage of multiple message objects ■ Gluelessly attaches to an external CAN transceiver through the CANnTX and CANnRX signals 1.3.5.3 Universal Serial Bus (USB) (see page 1644) Universal Serial Bus (USB) is a serial bus standard designed to allow peripherals to be connected and disconnected using a standardized interface without rebooting the system. The TM4C1294NCPDT microcontroller has one USB controller that supports high and full speed multi-point communications and complies with the USB 2.0 standard for high-speed function. The USB controller can have three configurations: USB Device, USB Host, and USB On-The-Go (negotiated on-the-go as host or device when connected to other USB-enabled systems). Support for full-speed communication is provided by using the integrated USB PHY or optionally, a high-speed ULPI interface can communicate to an external PHY. The USB module has the following features: ■ Complies with USB-IF (Implementer's Forum) certification standards ■ USB 2.0 high-speed (480 Mbps) operation with the integrated ULPI interface communicating with an external PHY ■ Link Power Management support which uses link-state awareness to reduce power usage ■ 4 transfer types: Control, Interrupt, Bulk, and Isochronous June 18, 2014 63 Texas Instruments-Production Data Architectural Overview ■ 16 endpoints – 1 dedicated control IN endpoint and 1 dedicated control OUT endpoint – 7 configurable IN endpoints and 7 configurable OUT endpoints ■ 4 KB dedicated endpoint memory: one endpoint may be defined for double-buffered 1023-byte isochronous packet size ■ VBUS droop detection and interrupt ■ Integrated USB DMA with bus master capability – Up to eight RX Endpoint channels and up to eight TX Endpoint channels are available. – Each channel can be separately programmed to operate in different modes – Incremental burst transfers of 4-, 8-, 16- or unspecified length supported 1.3.5.4 UART (see page 1161) A Universal Asynchronous Receiver/Transmitter (UART) is an integrated circuit used for RS-232C serial communications, containing a transmitter (parallel-to-serial converter) and a receiver (serial-to-parallel converter), each clocked separately. The TM4C1294NCPDT microcontroller includes eight fully programmable 16C550-type UARTs. Although the functionality is similar to a 16C550 UART, this UART design is not register compatible. The UART can generate individually masked interrupts from the Rx, Tx, modem flow control, modem status, and error conditions. The module generates a single combined interrupt when any of the interrupts are asserted and are unmasked. The eight UARTs have the following features: ■ Programmable baud-rate generator allowing speeds up to 7.5 Mbps for regular speed (divide by 16) and 15 Mbps for high speed (divide by 8) ■ Separate 16x8 transmit (TX) and receive (RX) FIFOs to reduce CPU interrupt service loading ■ Programmable FIFO length, including 1-byte deep operation providing conventional double-buffered interface ■ FIFO trigger levels of 1/8, 1/4, 1/2, 3/4, and 7/8 ■ Standard asynchronous communication bits for start, stop, and parity ■ Line-break generation and detection ■ Fully programmable serial interface characteristics – 5, 6, 7, or 8 data bits – Even, odd, stick, or no-parity bit generation/detection – 1 or 2 stop bit generation ■ IrDA serial-IR (SIR) encoder/decoder providing 64 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller – Programmable use of IrDA Serial Infrared (SIR) or UART input/output – Support of IrDA SIR encoder/decoder functions for data rates up to 115.2 Kbps half-duplex – Support of normal 3/16 and low-power (1.41-2.23 μs) bit durations – Programmable internal clock generator enabling division of reference clock by 1 to 256 for low-power mode bit duration ■ Support for communication with ISO 7816 smart cards ■ Modem functionality available on the following UARTs: – UART0 (modem flow control and modem status) – UART1 (modem flow control and modem status) – UART2 (modem flow control) – UART3 (modem flow control) – UART4 (modem flow control) ■ EIA-485 9-bit support ■ Standard FIFO-level and End-of-Transmission interrupts ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for transmit and receive – Receive single request asserted when data is in the FIFO; burst request asserted at programmed FIFO level – Transmit single request asserted when there is space in the FIFO; burst request asserted at programmed FIFO level ■ Global Alternate Clock (ALTCLK) resource or System Clock (SYSCLK) can be used to generate baud clock 1.3.5.5 I2C (see page 1275) The Inter-Integrated Circuit (I2C) bus provides bi-directional data transfer through a two-wire design (a serial data line SDA and a serial clock line SCL). The I2C bus interfaces to external I2C devices such as serial memory (RAMs and ROMs), networking devices, LCDs, tone generators, and so on. The I2C bus may also be used for system testing and diagnostic purposes in product development and manufacture. Each device on the I2C bus can be designated as either a master or a slave. I2C module supports both sending and receiving data as either a master or a slave and can operate simultaneously as both a master and a slave. Both the I2C master and slave can generate interrupts. The TM4C1294NCPDT microcontroller includes I2C modules with the following features: ■ Devices on the I2C bus can be designated as either a master or a slave – Supports both transmitting and receiving data as either a master or a slave June 18, 2014 65 Texas Instruments-Production Data Architectural Overview – Supports simultaneous master and slave operation ■ Four I2C modes – Master transmit – Master receive – Slave transmit – Slave receive ■ Two 8-entry FIFOs for receive and transmit data – FIFOs can be independently assigned to master or slave ■ Four transmission speeds: – Standard (100 Kbps) – Fast-mode (400 Kbps) – Fast-mode plus (1 Mbps) – High-speed mode (3.33 Mbps) ■ Glitch suppression ■ SMBus support through software – Clock low timeout interrupt – Dual slave address capability – Quick command capability ■ Master and slave interrupt generation – Master generates interrupts when a transmit or receive operation completes (or aborts due to an error) – Slave generates interrupts when data has been transferred or requested by a master or when a START or STOP condition is detected ■ Master with arbitration and clock synchronization, multimaster support, and 7-bit addressing mode ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for transmit and receive – Ability to execute single data transfers or burst data transfers using the RX and TX FIFOs in the I2C 66 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1.3.5.6 QSSI (see page 1226) Quad Synchronous Serial Interface (QSSI) is a bi-directional communications interface that converts data between parallel and serial. The QSSI module performs serial-to-parallel conversion on data received from a peripheral device, and parallel-to-serial conversion on data transmitted to a peripheral device. The QSSI module can be configured as either a master or slave device. As a slave device, the QSSI module can also be configured to disable its output, which allows a master device to be coupled with multiple slave devices. The TX and RX paths are buffered with separate internal FIFOs. The QSSI module also includes a programmable bit rate clock divider and prescaler to generate the output serial clock derived from the QSSI module's input clock. Bit rates are generated based on the input clock and the maximum bit rate is determined by the connected peripheral. The TM4C1294NCPDT microcontroller includes four QSSI modules with the following features: ■ Four QSSI channels with Advanced, Bi- and Quad-SSI functionality ■ Programmable interface operation for Freescale SPI or Texas Instruments synchronous serial interfaces in Legacy Mode. Support for Freescale interface in Bi- and Quad-SSI mode. ■ Master or slave operation ■ Programmable clock bit rate and prescaler ■ Separate transmit and receive FIFOs, each 16 bits wide and 8 locations deep ■ Programmable data frame size from 4 to 16 bits ■ Internal loopback test mode for diagnostic/debug testing ■ Standard FIFO-based interrupts and End-of-Transmission interrupt ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for transmit and receive – Receive single request asserted when data is in the FIFO; burst request asserted when FIFO contains 4 entries – Transmit single request asserted when there is space in the FIFO; burst request asserted when four or more entries are available to be written in the FIFO – Maskable µDMA interrupts for receive and transmit complete ■ Global Alternate Clock (ALTCLK) resource or System Clock (SYSCLK) can be used to generate baud clock. 1.3.6 System Integration The TM4C1294NCPDT microcontroller provides a variety of standard system functions integrated into the device, including: ■ Direct Memory Access Controller (DMA) ■ System control and clocks including on-chip precision 16-MHz oscillator ■ Eight 32-bit timers (each of which can be configured as two 16-bit timers) June 18, 2014 67 Texas Instruments-Production Data Architectural Overview ■ Lower-power battery-backed Hibernation module ■ Real-Time Clock in Hibernation module ■ Two Watchdog Timers – One timer runs off the main oscillator – One timer runs off the precision internal oscillator ■ Up to 90 GPIOs, depending on configuration – Highly flexible pin muxing allows use as GPIO or one of several peripheral functions – Independently configurable to 2-, 4-, 8-, 10-, or 12-mA drive capability – Up to 4 GPIOs can have 18-mA drive capability The following sections provide more detail on each of these functions. 1.3.6.1 Direct Memory Access (see page 678) The TM4C1294NCPDT microcontroller includes a Direct Memory Access (DMA) controller, known as micro-DMA (μDMA). The μDMA controller provides a way to offload data transfer tasks from the Cortex-M4F processor, allowing for more efficient use of the processor and the available bus bandwidth. The μDMA controller can perform transfers between memory and peripherals. It has dedicated channels for each supported on-chip module and can be programmed to automatically perform transfers between peripherals and memory as the peripheral is ready to transfer more data. The μDMA controller provides the following features: ® ■ ARM PrimeCell 32-channel configurable µDMA controller ■ Support for memory-to-memory, memory-to-peripheral, and peripheral-to-memory in multiple transfer modes – Basic for simple transfer scenarios – Ping-pong for continuous data flow – Scatter-gather for a programmable list of up to 256 arbitrary transfers initiated from a single request ■ Highly flexible and configurable channel operation – Independently configured and operated channels – Dedicated channels for supported on-chip modules – Flexible channel assignments – One channel each for receive and transmit path for bidirectional modules – Dedicated channel for software-initiated transfers – Per-channel configurable priority scheme – Optional software-initiated requests for any channel ■ Two levels of priority 68 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Design optimizations for improved bus access performance between µDMA controller and the processor core – µDMA controller access is subordinate to core access – RAM striping – Peripheral bus segmentation ■ Data sizes of 8, 16, and 32 bits ■ Transfer size is programmable in binary steps from 1 to 1024 ■ Source and destination address increment size of byte, half-word, word, or no increment ■ Maskable peripheral requests ■ Interrupt on transfer completion, with a separate interrupt per channel 1.3.6.2 System Control and Clocks (see page 220) System control determines the overall operation of the device. It provides information about the device, controls power-saving features, controls the clocking of the device and individual peripherals, and handles reset detection and reporting. ■ Device identification information: version, part number, SRAM size, Flash memory size, and so on ■ Power control – On-chip fixed Low Drop-Out (LDO) voltage regulator – Hibernation module handles the power-up/down 3.3 V sequencing and control for the core digital logic and analog circuits – Low-power options for microcontroller: Sleep and Deep-Sleep modes with clock gating – Low-power options for on-chip modules: software controls shutdown of individual peripherals and memory – 3.3-V supply brown-out detection and reporting via interrupt or reset ■ Multiple clock sources for microcontroller system clock. The TM4C1294NCPDT microcontroller is clocked by the system clock (SYSCLK) that is distributed to the processor and integrated peripherals after clock gating. The SYSCLK frequency is based on the frequency of the clock source and a divisor factor. A PLL is provided for the generation of system clock frequencies in excess of the reference clock provided. The reference clocks for the PLL are the PIOSC and the main crystal oscillator. The following clock sources are provided to the TM4C1294NCPDT microcontroller: – 16-MHz Precision Oscillator (PIOSC) – Main Oscillator (MOSC): A frequency-accurate clock source by one of two means: an external single-ended clock source is connected to the OSC0 input pin, or an external crystal is connected across the OSC0 input and OSC1 output pins. June 18, 2014 69 Texas Instruments-Production Data Architectural Overview – Low Frequency Internal Oscillator (LFIOSC): On-chip resource used during power-saving modes – Hibernate RTC oscillator (RTCOSC) clock that can be configured to be the 32.768-kHz external oscillator source from the Hibernation (HIB) module or the HIB Low Frequency clock source (HIB LFIOSC), which is located within the Hibernation Module. ■ Flexible reset sources – Power-on reset (POR) – Reset pin assertion – Brown-out reset (BOR) detector alerts to system power drops – Software reset – Watchdog timer reset – Hibernation module event – MOSC failure ■ 128-bit unique identifier for individual device identification 1.3.6.3 Programmable Timers (see page 955) Programmable timers can be used to count or time external events that drive the Timer input pins. Each 16/32-bit GPTM block provides two 16-bit timers/counters that can be configured to operate independently as timers or event counters, or configured to operate as one 32-bit timer or one 32-bit Real-Time Clock (RTC). Timers can also be used to trigger analog-to-digital (ADC) conversions and DMA transfers. The General-Purpose Timer Module (GPTM) contains eight 16/32-bit GPTM blocks with the following functional options: ■ Operating modes: – 16- or 32-bit programmable one-shot timer – 16- or 32-bit programmable periodic timer – 16-bit general-purpose timer with an 8-bit prescaler – 32-bit Real-Time Clock (RTC) when using an external 32.768-KHz clock as the input – 16-bit input-edge count- or time-capture modes with an 8-bit prescaler – 16-bit PWM mode with an 8-bit prescaler and software-programmable output inversion of the PWM signal – The System Clock or a global Alternate Clock (ALTCLK) resource can be used as timer clock source. The global ALTCLK can be: • PIOSC • Hibernation Module Real-time clock output (RTCOSC) 70 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller • Low-frequency internal oscillator (LFIOSC) ■ Count up or down ■ Twelve 16/32-bit Capture Compare PWM pins (CCP) ■ Daisy chaining of timer modules to allow a single timer to initiate multiple timing events ■ Timer synchronization allows selected timers to start counting on the same clock cycle ■ ADC event trigger ■ User-enabled stalling when the microcontroller asserts CPU Halt flag during debug (excluding RTC mode) ■ Ability to determine the elapsed time between the assertion of the timer interrupt and entry into the interrupt service routine ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Dedicated channel for each timer – Burst request generated on timer interrupt 1.3.6.4 CCP Pins (see page 962) Capture Compare PWM pins (CCP) can be used by the General-Purpose Timer Module to time/count external events using the CCP pin as an input. Alternatively, the GPTM can generate a simple PWM output on the CCP pin. The TM4C1294NCPDT microcontroller includes twelve 16/32-bit CCP pins that can be programmed to operate in the following modes: ■ Capture: The GP Timer is incremented/decremented by programmed events on the CCP input. The GP Timer captures and stores the current timer value when a programmed event occurs. ■ Compare: The GP Timer is incremented/decremented by programmed events on the CCP input. The GP Timer compares the current value with a stored value and generates an interrupt when a match occurs. ■ PWM: The GP Timer is incremented/decremented by the system clock. A PWM signal is generated based on a match between the counter value and a value stored in a match register and is output on the CCP pin. 1.3.6.5 Hibernation Module (HIB) (see page 531) The Hibernation module provides logic to switch power off to the main processor and peripherals and to wake on external or time-based events. The Hibernation module includes power-sequencing logic and has the following features: ■ 32-bit real-time seconds counter (RTC) with 1/32,768 second resolution and a 15-bit sub-seconds counter – 32-bit RTC seconds match register and a 15-bit sub seconds match for timed wake-up and interrupt generation with 1/32,768 second resolution – RTC predivider trim for making fine adjustments to the clock rate June 18, 2014 71 Texas Instruments-Production Data Architectural Overview ■ Hardware Calendar Function – Year, Month, Day, Day of Week, Hours, Minutes, Seconds – Four-year leap compensation – 24-hour or AM/PM configuration ■ Two mechanisms for power control – System power control using discrete external regulator – On-chip power control using internal switches under register control ■ VDD supplies power when valid, even if VBAT > VDD ■ Dedicated pin for waking using an external signal ■ Capability to configure external reset (RST) pin and/or up to four GPIO port pins as wake source, with programmable wake level ■ Tamper Functionality – Support for four tamper inputs – Configurable level, weak pull-up, and glitch filter – Configurable tamper event response – Logging of up to four tamper events – Optional BBRAM erase on tamper detection – Tamper wake from hibernate capability – Hibernation clock input failure detect with a switch to the internal oscillator on detection ■ RTC operational and hibernation memory valid as long as VDD or VBAT is valid ■ Low-battery detection, signaling, and interrupt generation, with optional wake on low battery ■ GPIO pin state can be retained during hibernation ■ Clock source from an internal low frequency oscillator (HIB LFIOSC) or a 32.768-kHz external crystal or oscillator ■ Sixteen 32-bit words of battery-backed memory to save state during hibernation ■ Programmable interrupts for: – RTC match – External wake – Low battery 72 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1.3.6.6 Watchdog Timers (see page 1028) A watchdog timer is used to regain control when a system has failed due to a software error or to the failure of an external device to respond in the expected way. The TM4C1294NCPDT Watchdog Timer can generate an interrupt, a non-maskable interrupt, or a reset when a time-out value is reached. In addition, the Watchdog Timer is ARM FiRM-compliant and can be configured to generate an interrupt to the microcontroller on its first time-out, and to generate a reset signal on its second timeout. Once the Watchdog Timer has been configured, the lock register can be written to prevent the timer configuration from being inadvertently altered. The TM4C1294NCPDT microcontroller has two Watchdog Timer modules: Watchdog Timer 0 uses the system clock for its timer clock; Watchdog Timer 1 uses the PIOSC as its timer clock. The Watchdog Timer module has the following features: ■ 32-bit down counter with a programmable load register ■ Separate watchdog clock with an enable ■ Programmable interrupt generation logic with interrupt masking and optional NMI function ■ Lock register protection from runaway software ■ Reset generation logic with an enable/disable ■ User-enabled stalling when the microcontroller asserts the CPU Halt flag during debug 1.3.6.7 Programmable GPIOs (see page 742) General-purpose input/output (GPIO) pins offer flexibility for a variety of connections. The TM4C1294NCPDT GPIO module is comprised of 15 physical GPIO blocks, each corresponding to an individual GPIO port. The GPIO module is FiRM-compliant (compliant to the ARM Foundation IP for Real-Time Microcontrollers specification) and supports 0-90 programmable input/output pins. The number of GPIOs available depends on the peripherals being used (see “Signal Tables” on page 1772 for the signals available to each GPIO pin). ■ Up to 90 GPIOs, depending on configuration ■ Highly flexible pin muxing allows use as GPIO or one of several peripheral functions ■ 3.3-V-tolerant in input configuration ■ Advanced High Performance Bus accesses all ports: – Ports A-H and J; Ports K-N and P-Q ■ Fast toggle capable of a change every clock cycle for ports on AHB ■ Programmable control for GPIO interrupts – Interrupt generation masking – Edge-triggered on rising, falling, or both – Level-sensitive on High or Low values – Per-pin interrupts available on Port P and Port Q June 18, 2014 73 Texas Instruments-Production Data Architectural Overview ■ Bit masking in both read and write operations through address lines ■ Can be used to initiate an ADC sample sequence or a μDMA transfer ■ Pin state can be retained during Hibernation mode; pins on port P can be programmed to wake on level in Hibernation mode ■ Pins configured as digital inputs are Schmitt-triggered ■ Programmable control for GPIO pad configuration – Weak pull-up or pull-down resistors – 2-mA, 4-mA, 6-mA, 8-mA, 10-mA and 12-mA pad drive for digital communication; up to four pads can sink 18-mA for high-current applications – Slew rate control for 8-mA, 10-mA and 12-mA pad drive – Open drain enables – Digital input enables 1.3.7 Advanced Motion Control The TM4C1294NCPDT microcontroller provides motion control functions integrated into the device, including: ■ Eight advanced PWM outputs for motion and energy applications ■ Four fault inputs to promote low-latency shutdown ■ One Quadrature Encoder Input (QEI) The following provides more detail on these motion control functions. 1.3.7.1 PWM (see page 1669) The TM4C1294NCPDT microcontroller contains one PWM module, with four PWM generator blocks and a control block, for a total of 8 PWM outputs. Pulse width modulation (PWM) is a powerful technique for digitally encoding analog signal levels. High-resolution counters are used to generate a square wave, and the duty cycle of the square wave is modulated to encode an analog signal. Typical applications include switching power supplies and motor control. The TM4C1294NCPDT PWM module consists of four PWM generator block and a control block. Each PWM generator block contains one timer (16-bit down or up/down counter), two comparators, a PWM signal generator, a dead-band generator, and an interrupt/ADC-trigger selector. Each PWM generator block produces two PWM signals that can either be independent signals or a single pair of complementary signals with dead-band delays inserted. Each PWM generator has the following features: ■ Four fault-condition handling inputs to quickly provide low-latency shutdown and prevent damage to the motor being controlled ■ One 16-bit counter – Runs in Down or Up/Down mode 74 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller – Output frequency controlled by a 16-bit load value – Load value updates can be synchronized – Produces output signals at zero and load value ■ Two PWM comparators – Comparator value updates can be synchronized – Produces output signals on match ■ PWM signal generator – Output PWM signal is constructed based on actions taken as a result of the counter and PWM comparator output signals – Produces two independent PWM signals ■ Dead-band generator – Produces two PWM signals with programmable dead-band delays suitable for driving a half-H bridge – Can be bypassed, leaving input PWM signals unmodified ■ Can initiate an ADC sample sequence The control block determines the polarity of the PWM signals and which signals are passed through to the pins. The output of the PWM generation blocks are managed by the output control block before being passed to the device pins. The PWM control block has the following options: ■ PWM output enable of each PWM signal ■ Optional output inversion of each PWM signal (polarity control) ■ Optional fault handling for each PWM signal ■ Synchronization of timers in the PWM generator blocks ■ Synchronization of timer/comparator updates across the PWM generator blocks ■ Extended PWM synchronization of timer/comparator updates across the PWM generator blocks ■ Interrupt status summary of the PWM generator blocks ■ Extended PWM fault handling, with multiple fault signals, programmable polarities, and filtering ■ PWM generators can be operated independently or synchronized with other generators 1.3.7.2 QEI (see page 1748) A quadrature encoder, also known as a 2-channel incremental encoder, converts linear displacement into a pulse signal. By monitoring both the number of pulses and the relative phase of the two signals, the position, direction of rotation, and speed can be tracked. In addition, a third channel, or index signal, can be used to reset the position counter. The TM4C1294NCPDT quadrature encoder with index (QEI) module interprets the code produced by a quadrature encoder wheel to integrate position June 18, 2014 75 Texas Instruments-Production Data Architectural Overview over time and determine direction of rotation. In addition, it can capture a running estimate of the velocity of the encoder wheel. The input frequency of the QEI inputs may be as high as 1/4 of the processor frequency (for example, 30 MHz for a 120-MHz system). The TM4C1294NCPDT microcontroller includes one QEI module providing control of one motor with the following features: ■ Position integrator that tracks the encoder position ■ Programmable noise filter on the inputs ■ Velocity capture using built-in timer ■ The input frequency of the QEI inputs may be as high as 1/4 of the processor frequency (for example, 12.5 MHz for a 50-MHz system) ■ Interrupt generation on: – Index pulse – Velocity-timer expiration – Direction change – Quadrature error detection 1.3.8 Analog The TM4C1294NCPDT microcontroller provides analog functions integrated into the device, including: ■ Two 12-bit Analog-to-Digital Converters (ADC), with a total of 20 analog input channels and each with a sample rate of two million samples/second ■ Three analog comparators ■ On-chip voltage regulator The following provides more detail on these analog functions. 1.3.8.1 ADC (see page 1053) An analog-to-digital converter (ADC) is a peripheral that converts a continuous analog voltage to a discrete digital number. The TM4C1294NCPDT ADC module features 12-bit conversion resolution and supports 20 input channels plus an internal temperature sensor. Four buffered sample sequencers allow rapid sampling of up to 20 analog input sources without controller intervention. Each sample sequencer provides flexible programming with fully configurable input source, trigger events, interrupt generation, and sequencer priority. Each ADC module has a digital comparator function that allows the conversion value to be diverted to a comparison unit that provides eight digital comparators. The TM4C1294NCPDT microcontroller provides two ADC modules, each with the following features: ■ 20 shared analog input channels ■ 12-bit precision ADC ■ Single-ended and differential-input configurations 76 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ On-chip internal temperature sensor ■ Maximum sample rate of two million samples/second ■ Optional, programmable phase delay ■ Sample and hold window programmability ■ Four programmable sample conversion sequencers from one to eight entries long, with corresponding conversion result FIFOs ■ Flexible trigger control – Controller (software) – Timers – Analog Comparators – PWM – GPIO ■ Hardware averaging of up to 64 samples ■ Eight digital comparators ■ Converter uses signals VREFA+ and GNDA as the voltage reference ■ Power and ground for the analog circuitry is separate from the digital power and ground ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Dedicated channel for each sample sequencer – ADC module uses burst requests for DMA ■ Global Alternate Clock (ALTCLK) resource or System Clock (SYSCLK) can be used to generate ADC clock 1.3.8.2 Analog Comparators (see page 1653) An analog comparator is a peripheral that compares two analog voltages and provides a logical output that signals the comparison result. The TM4C1294NCPDT microcontroller provides three independent integrated analog comparators that can be configured to drive an output or generate an interrupt or ADC event. The comparator can provide its output to a device pin, acting as a replacement for an analog comparator on the board, or it can be used to signal the application via interrupts or triggers to the ADC to cause it to start capturing a sample sequence. The interrupt generation and ADC triggering logic is separate. This means, for example, that an interrupt can be generated on a rising edge and the ADC triggered on a falling edge. The TM4C1294NCPDT microcontroller provides three independent integrated analog comparators with the following functions: ■ Compare external pin input to external pin input or to internal programmable voltage reference June 18, 2014 77 Texas Instruments-Production Data Architectural Overview ■ Compare a test voltage against any one of the following voltages: – An individual external reference voltage – A shared single external reference voltage – A shared internal reference voltage 1.3.9 JTAG and ARM Serial Wire Debug (see page 207) The Joint Test Action Group (JTAG) port is an IEEE standard that defines a Test Access Port and Boundary Scan Architecture for digital integrated circuits and provides a standardized serial interface for controlling the associated test logic. The TAP, Instruction Register (IR), and Data Registers (DR) can be used to test the interconnections of assembled printed circuit boards and obtain manufacturing information on the components. The JTAG Port also provides a means of accessing and controlling design-for-test features such as I/O pin observation and control, scan testing, and debugging. Texas Instruments replaces the ARM SW-DP and JTAG-DP with the ARM Serial Wire JTAG Debug Port (SWJ-DP) interface. The SWJ-DP interface combines the SWD and JTAG debug ports into one module providing all the normal JTAG debug and test functionality plus real-time access to system memory without halting the core or requiring any target resident code. The SWJ-DP interface has the following features: ■ IEEE 1149.1-1990 compatible Test Access Port (TAP) controller ■ Four-bit Instruction Register (IR) chain for storing JTAG instructions ■ IEEE standard instructions: BYPASS, IDCODE, SAMPLE/PRELOAD, and EXTEST ■ ARM additional instructions: APACC, DPACC and ABORT ■ Integrated ARM Serial Wire Debug (SWD) – Serial Wire JTAG Debug Port (SWJ-DP) – Flash Patch and Breakpoint (FPB) unit for implementing breakpoints – Data Watchpoint and Trace (DWT) unit for implementing watchpoints, trigger resources, and system profiling – Instrumentation Trace Macrocell (ITM) for support of printf style debugging – Embedded Trace Macrocell (ETM) for instruction trace capture – Trace Port Interface Unit (TPIU) for bridging to a Trace Port Analyzer 1.3.10 Packaging and Temperature ■ 128-pin RoHS-compliant TQFP package ■ Industrial (-40°C to 85°C) ambient temperature range ■ Extended (-40°C to 105°C) ambient temperature range 1.4 TM4C1294NCPDT Microcontroller Hardware Details Details on the pins and package can be found in the following sections: 78 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ “Pin Diagram” on page 1771 ■ “Signal Tables” on page 1772 ■ “Electrical Characteristics” on page 1818 ■ “Package Information” on page 1885 1.5 Kits The Tiva™ C Series provides the hardware and software tools that engineers need to begin development quickly. ■ Reference Design Kits accelerate product development by providing ready-to-run hardware and comprehensive documentation including hardware design files ■ Evaluation Kits provide a low-cost and effective means of evaluating TM4C1294NCPDT microcontrollers before purchase ■ Development Kits provide you with all the tools you need to develop and prototype embedded applications right out of the box See the Tiva series website at http://www.ti.com/tiva-c for the latest tools available, or ask your distributor. 1.6 Support Information For support on Tiva™ C Series products, contact the TI Worldwide Product Information Center nearest you. June 18, 2014 79 Texas Instruments-Production Data The Cortex-M4F Processor 2 The Cortex-M4F Processor The ARM® Cortex™-M4F processor provides a high-performance, low-cost platform that meets the system requirements of minimal memory implementation, reduced pin count, and low power consumption, while delivering outstanding computational performance and exceptional system response to interrupts. Features include: ® ■ 32-bit ARM Cortex™-M4F architecture optimized for small-footprint embedded applications ■ 120-MHz operation; 150 DMIPS performance ■ Outstanding processing performance combined with fast interrupt handling ■ Thumb-2 mixed 16-/32-bit instruction set delivers the high performance expected of a 32-bit ARM core in a compact memory size usually associated with 8- and 16-bit devices, typically in the range of a few kilobytes of memory for microcontroller-class applications – Single-cycle multiply instruction and hardware divide – Atomic bit manipulation (bit-banding), delivering maximum memory utilization and streamlined peripheral control – Unaligned data access, enabling data to be efficiently packed into memory ■ IEEE754-compliant single-precision Floating-Point Unit (FPU) ■ 16-bit SIMD vector processing unit ■ Fast code execution permits slower processor clock or increases sleep mode time ■ Harvard architecture characterized by separate buses for instruction and data ■ Efficient processor core, system and memories ■ Hardware division and fast digital-signal-processing orientated multiply accumulate ■ Saturating arithmetic for signal processing ■ Deterministic, high-performance interrupt handling for time-critical applications ■ Memory protection unit (MPU) to provide a privileged mode for protected operating system functionality ■ Enhanced system debug with extensive breakpoint and trace capabilities ■ Serial Wire Debug and Serial Wire Trace reduce the number of pins required for debugging and tracing ■ Migration from the ARM7™ processor family for better performance and power efficiency ■ Optimized for single-cycle Flash memory usage up to specific frequencies; see “Internal Memory” on page 600 for more information. ■ Ultra-low power consumption with integrated sleep modes 80 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The Tiva™ C Series microcontrollers builds on this core to bring high-performance 32-bit computing to cost-conscious applications requiring significant control processing and connectivity capabilities such as: ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Low power, hand-held smart devices Gaming equipment Network appliances and switches Home and commercial site monitoring and control Electronic point-of-sale (POS) machines Motion control Medical instrumentation Remote connectivity and monitoring Test and measurement equipment Factory automation Fire and security Smart Energy/Smart Grid solutions Intelligent lighting control Transportation This chapter provides information on the Tiva™ C Series implementation of the Cortex-M4F processor, including the programming model, the memory model, the exception model, fault handling, and power management. For technical details on the instruction set, see the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A). 2.1 Block Diagram The Cortex-M4F processor is built on a high-performance processor core, with a 3-stage pipeline Harvard architecture, making it ideal for demanding embedded applications. The processor delivers exceptional power efficiency through an efficient instruction set and extensively optimized design, providing high-end processing hardware including IEEE754-compliant single-precision floating-point computation, a range of single-cycle and SIMD multiplication and multiply-with-accumulate capabilities, saturating arithmetic and dedicated hardware division. To facilitate the design of cost-sensitive devices, the Cortex-M4F processor implements tightly coupled system components that reduce processor area while significantly improving interrupt handling and system debug capabilities. The Cortex-M4F processor implements a version of the Thumb® instruction set based on Thumb-2 technology, ensuring high code density and reduced program memory requirements. The Cortex-M4F instruction set provides the exceptional performance expected of a modern 32-bit architecture, with the high code density of 8-bit and 16-bit microcontrollers. The Cortex-M4F processor closely integrates a nested interrupt controller (NVIC), to deliver industry-leading interrupt performance. The TM4C1294NCPDT NVIC includes a non-maskable interrupt (NMI) and provides eight interrupt priority levels. The tight integration of the processor core and NVIC provides fast execution of interrupt service routines (ISRs), dramatically reducing interrupt latency. The hardware stacking of registers and the ability to suspend load-multiple and store-multiple operations further reduce interrupt latency. Interrupt handlers do not require any assembler stubs which removes code overhead from the ISRs. Tail-chaining optimization also significantly reduces the overhead when switching from one ISR to another. To optimize low-power designs, the NVIC integrates with the sleep modes, including Deep-sleep mode, which enables the entire device to be rapidly powered down. June 18, 2014 81 Texas Instruments-Production Data The Cortex-M4F Processor Figure 2-1. CPU Block Diagram Nested Vectored Interrupt Controller FPU Interrupts Sleep ARM Cortex-M4F CM4 Core Debug Instructions Data Embedded Trace Macrocell Memory Protection Unit Flash Patch and Breakpoint Instrumentation Data Watchpoint Trace Macrocell and Trace ROM Table Private Peripheral Bus (internal) Adv. Peripheral Bus Bus Matrix Serial Wire JTAG Debug Port Debug Access Port 2.2 Overview 2.2.1 System-Level Interface Trace Port Interface Unit Serial Wire Output Trace Port (SWO) I-code bus D-code bus System bus The Cortex-M4F processor provides multiple interfaces using AMBA® technology to provide high-speed, low-latency memory accesses. The core supports unaligned data accesses and implements atomic bit manipulation that enables faster peripheral controls, system spinlocks, and thread-safe Boolean data handling. The Cortex-M4F processor has a memory protection unit (MPU) that provides fine-grain memory control, enabling applications to implement security privilege levels and separate code, data and stack on a task-by-task basis. 2.2.2 Integrated Configurable Debug The Cortex-M4F processor implements a complete hardware debug solution, providing high system visibility of the processor and memory through either a traditional JTAG port or a 2-pin Serial Wire Debug (SWD) port that is ideal for microcontrollers and other small package devices. The Tiva™ C Series implementation replaces the ARM SW-DP and JTAG-DP with the ARM CoreSight™-compliant Serial Wire JTAG Debug Port (SWJ-DP) interface. The SWJ-DP interface combines the SWD and JTAG debug ports into one module. See the ARM® Debug Interface V5 Architecture Specification for details on SWJ-DP. For system trace, the processor integrates an Instrumentation Trace Macrocell (ITM) alongside data watchpoints and a profiling unit. To enable simple and cost-effective profiling of the system trace events, a Serial Wire Viewer (SWV) can export a stream of software-generated messages, data trace, and profiling information through a single pin. 82 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The Embedded Trace Macrocell (ETM) delivers unrivaled instruction trace capture in an area smaller than traditional trace units, enabling full instruction trace. For more details on the ARM ETM, see the ARM® Embedded Trace Macrocell Architecture Specification. The Flash Patch and Breakpoint Unit (FPB) provides up to eight hardware breakpoint comparators that debuggers can use. The comparators in the FPB also provide remap functions for up to eight words of program code in the code memory region. This FPB enables applications stored in a read-only area of Flash memory to be patched in another area of on-chip SRAM or Flash memory. If a patch is required, the application programs the FPB to remap a number of addresses. When those addresses are accessed, the accesses are redirected to a remap table specified in the FPB configuration. For more information on the Cortex-M4F debug capabilities, see theARM® Debug Interface V5 Architecture Specification. 2.2.3 Trace Port Interface Unit (TPIU) The TPIU acts as a bridge between the Cortex-M4F trace data from the ITM, and an off-chip Trace Port Analyzer, as shown in Figure 2-2 on page 83. Figure 2-2. TPIU Block Diagram 2.2.4 Debug ATB Slave Port ARM® Trace Bus (ATB) Interface APB Slave Port Advance Peripheral Bus (APB) Interface Asynchronous FIFO Trace Out (serializer) Serial Wire Trace Port (SWO) Cortex-M4F System Component Details The Cortex-M4F includes the following system components: ■ SysTick A 24-bit count-down timer that can be used as a Real-Time Operating System (RTOS) tick timer or as a simple counter (see “System Timer (SysTick)” on page 135). ■ Nested Vectored Interrupt Controller (NVIC) June 18, 2014 83 Texas Instruments-Production Data The Cortex-M4F Processor An embedded interrupt controller that supports low latency interrupt processing (see “Nested Vectored Interrupt Controller (NVIC)” on page 136). ■ System Control Block (SCB) The programming model interface to the processor. The SCB provides system implementation information and system control, including configuration, control, and reporting of system exceptions (see “System Control Block (SCB)” on page 137). ■ Memory Protection Unit (MPU) Improves system reliability by defining the memory attributes for different memory regions. The MPU provides up to eight different regions and an optional predefined background region (see “Memory Protection Unit (MPU)” on page 137). ■ Floating-Point Unit (FPU) Fully supports single-precision add, subtract, multiply, divide, multiply and accumulate, and square-root operations. It also provides conversions between fixed-point and floating-point data formats, and floating-point constant instructions (see “Floating-Point Unit (FPU)” on page 142). 2.3 Programming Model This section describes the Cortex-M4F programming model. In addition to the individual core register descriptions, information about the processor modes and privilege levels for software execution and stacks is included. 2.3.1 Processor Mode and Privilege Levels for Software Execution The Cortex-M4F has two modes of operation: ■ Thread mode Used to execute application software. The processor enters Thread mode when it comes out of reset. ■ Handler mode Used to handle exceptions. When the processor has finished exception processing, it returns to Thread mode. In addition, the Cortex-M4F has two privilege levels: ■ Unprivileged In this mode, software has the following restrictions: – Limited access to the MSR and MRS instructions and no use of the CPS instruction – No access to the system timer, NVIC, or system control block – Possibly restricted access to memory or peripherals ■ Privileged In this mode, software can use all the instructions and has access to all resources. In Thread mode, the CONTROL register (see page 99) controls whether software execution is privileged or unprivileged. In Handler mode, software execution is always privileged. 84 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Only privileged software can write to the CONTROL register to change the privilege level for software execution in Thread mode. Unprivileged software can use the SVC instruction to make a supervisor call to transfer control to privileged software. 2.3.2 Stacks The processor uses a full descending stack, meaning that the stack pointer indicates the last stacked item on the memory. When the processor pushes a new item onto the stack, it decrements the stack pointer and then writes the item to the new memory location. The processor implements two stacks: the main stack and the process stack, with a pointer for each held in independent registers (see the SP register on page 89). In Thread mode, the CONTROL register (see page 99) controls whether the processor uses the main stack or the process stack. In Handler mode, the processor always uses the main stack. The options for processor operations are shown in Table 2-1 on page 85. Table 2-1. Summary of Processor Mode, Privilege Level, and Stack Use Processor Mode Use Privilege Level Thread Applications Privileged or unprivileged Handler Exception handlers Always privileged Stack Used a Main stack or process stack a Main stack a. See CONTROL (page 99). 2.3.3 Register Map Figure 2-3 on page 86 shows the Cortex-M4F register set. Table 2-2 on page 86 lists the Core registers. The core registers are not memory mapped and are accessed by register name, so the base address is n/a (not applicable) and there is no offset. June 18, 2014 85 Texas Instruments-Production Data The Cortex-M4F Processor Figure 2-3. Cortex-M4F Register Set R0 R1 R2 R3 Low registers R4 R5 General-purpose registers R6 R7 R8 R9 High registers R10 R11 R12 Stack Pointer SP (R13) Link Register LR (R14) Program Counter PC (R15) PSP‡ PSR MSP‡ ‡ Banked version of SP Program status register PRIMASK FAULTMASK Exception mask registers Special registers BASEPRI CONTROL CONTROL register Table 2-2. Processor Register Map Offset Name Type Reset Description See page - R0 RW - Cortex General-Purpose Register 0 88 - R1 RW - Cortex General-Purpose Register 1 88 - R2 RW - Cortex General-Purpose Register 2 88 - R3 RW - Cortex General-Purpose Register 3 88 - R4 RW - Cortex General-Purpose Register 4 88 - R5 RW - Cortex General-Purpose Register 5 88 - R6 RW - Cortex General-Purpose Register 6 88 - R7 RW - Cortex General-Purpose Register 7 88 - R8 RW - Cortex General-Purpose Register 8 88 - R9 RW - Cortex General-Purpose Register 9 88 - R10 RW - Cortex General-Purpose Register 10 88 - R11 RW - Cortex General-Purpose Register 11 88 86 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 2-2. Processor Register Map (continued) Offset Name Type Reset Description See page - R12 RW - Cortex General-Purpose Register 12 88 - SP RW - Stack Pointer 89 - LR RW 0xFFFF.FFFF Link Register 90 - PC RW - Program Counter 91 - PSR RW 0x0100.0000 Program Status Register 92 - PRIMASK RW 0x0000.0000 Priority Mask Register 96 - FAULTMASK RW 0x0000.0000 Fault Mask Register 97 - BASEPRI RW 0x0000.0000 Base Priority Mask Register 98 - CONTROL RW 0x0000.0000 Control Register 99 - FPSC RW - Floating-Point Status Control 101 2.3.4 Register Descriptions This section lists and describes the Cortex-M4F registers, in the order shown in Figure 2-3 on page 86. The core registers are not memory mapped and are accessed by register name rather than offset. Note: The register type shown in the register descriptions refers to type during program execution in Thread mode and Handler mode. Debug access can differ. June 18, 2014 87 Texas Instruments-Production Data The Cortex-M4F Processor Register 1: Cortex General-Purpose Register 0 (R0) Register 2: Cortex General-Purpose Register 1 (R1) Register 3: Cortex General-Purpose Register 2 (R2) Register 4: Cortex General-Purpose Register 3 (R3) Register 5: Cortex General-Purpose Register 4 (R4) Register 6: Cortex General-Purpose Register 5 (R5) Register 7: Cortex General-Purpose Register 6 (R6) Register 8: Cortex General-Purpose Register 7 (R7) Register 9: Cortex General-Purpose Register 8 (R8) Register 10: Cortex General-Purpose Register 9 (R9) Register 11: Cortex General-Purpose Register 10 (R10) Register 12: Cortex General-Purpose Register 11 (R11) Register 13: Cortex General-Purpose Register 12 (R12) The Rn registers are 32-bit general-purpose registers for data operations and can be accessed from either privileged or unprivileged mode. Cortex General-Purpose Register 0 (R0) Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - DATA Type Reset DATA Type Reset Bit/Field Name Type Reset 31:0 DATA RW - Description Register data. 88 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 14: Stack Pointer (SP) The Stack Pointer (SP) is register R13. In Thread mode, the function of this register changes depending on the ASP bit in the Control Register (CONTROL) register. When the ASP bit is clear, this register is the Main Stack Pointer (MSP). When the ASP bit is set, this register is the Process Stack Pointer (PSP). On reset, the ASP bit is clear, and the processor loads the MSP with the value from address 0x0000.0000. The MSP can only be accessed in privileged mode; the PSP can be accessed in either privileged or unprivileged mode. Stack Pointer (SP) Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - SP Type Reset SP Type Reset Bit/Field Name Type Reset 31:0 SP RW - Description This field is the address of the stack pointer. June 18, 2014 89 Texas Instruments-Production Data The Cortex-M4F Processor Register 15: Link Register (LR) The Link Register (LR) is register R14, and it stores the return information for subroutines, function calls, and exceptions. The Link Register can be accessed from either privileged or unprivileged mode. EXC_RETURN is loaded into the LR on exception entry. See Table 2-10 on page 123 for the values and description. Link Register (LR) Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 LINK Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 LINK Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 Bit/Field Name Type 31:0 LINK RW RW 1 Reset RW 1 Description 0xFFFF.FFFF This field is the return address. 90 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 16: Program Counter (PC) The Program Counter (PC) is register R15, and it contains the current program address. On reset, the processor loads the PC with the value of the reset vector, which is at address 0x0000.0004. Bit 0 of the reset vector is loaded into the THUMB bit of the EPSR at reset and must be 1. The PC register can be accessed in either privileged or unprivileged mode. Program Counter (PC) Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - PC Type Reset PC Type Reset Bit/Field Name Type Reset 31:0 PC RW - Description This field is the current program address. June 18, 2014 91 Texas Instruments-Production Data The Cortex-M4F Processor Register 17: Program Status Register (PSR) Note: This register is also referred to as xPSR. The Program Status Register (PSR) has three functions, and the register bits are assigned to the different functions: ■ Application Program Status Register (APSR), bits 31:27, bits 19:16 ■ Execution Program Status Register (EPSR), bits 26:24, 15:10 ■ Interrupt Program Status Register (IPSR), bits 7:0 The PSR, IPSR, and EPSR registers can only be accessed in privileged mode; the APSR register can be accessed in either privileged or unprivileged mode. APSR contains the current state of the condition flags from previous instruction executions. EPSR contains the Thumb state bit and the execution state bits for the If-Then (IT) instruction or the Interruptible-Continuable Instruction (ICI) field for an interrupted load multiple or store multiple instruction. Attempts to read the EPSR directly through application software using the MSR instruction always return zero. Attempts to write the EPSR using the MSR instruction in application software are always ignored. Fault handlers can examine the EPSR value in the stacked PSR to determine the operation that faulted (see “Exception Entry and Return” on page 120). IPSR contains the exception type number of the current Interrupt Service Routine (ISR). These registers can be accessed individually or as a combination of any two or all three registers, using the register name as an argument to the MSR or MRS instructions. For example, all of the registers can be read using PSR with the MRS instruction, or APSR only can be written to using APSR with the MSR instruction. page 92 shows the possible register combinations for the PSR. See the MRS and MSR instruction descriptions in the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information about how to access the program status registers. Table 2-3. PSR Register Combinations Register Type PSR RW Combination APSR, EPSR, and IPSR IEPSR RO EPSR and IPSR a, b a APSR and IPSR b APSR and EPSR IAPSR RW EAPSR RW a. The processor ignores writes to the IPSR bits. b. Reads of the EPSR bits return zero, and the processor ignores writes to these bits. Program Status Register (PSR) Type RW, reset 0x0100.0000 Type Reset 31 30 29 28 27 N Z C V Q 26 RW 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RO 1 RO 0 RO 0 RO 0 RO 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 ICI / IT Type Reset RO 0 RO 0 RO 0 25 ICI / IT 24 23 22 THUMB 21 RO 0 RO 0 RO 0 RO 0 19 18 17 16 RW 0 RW 0 RW 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 GE reserved RO 0 20 reserved ISRNUM RO 0 RO 0 92 RO 0 RO 0 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 31 N RW 0 Description APSR Negative or Less Flag Value Description 1 The previous operation result was negative or less than. 0 The previous operation result was positive, zero, greater than, or equal. The value of this bit is only meaningful when accessing PSR or APSR. 30 Z RW 0 APSR Zero Flag Value Description 1 The previous operation result was zero. 0 The previous operation result was non-zero. The value of this bit is only meaningful when accessing PSR or APSR. 29 C RW 0 APSR Carry or Borrow Flag Value Description 1 The previous add operation resulted in a carry bit or the previous subtract operation did not result in a borrow bit. 0 The previous add operation did not result in a carry bit or the previous subtract operation resulted in a borrow bit. The value of this bit is only meaningful when accessing PSR or APSR. 28 V RW 0 APSR Overflow Flag Value Description 1 The previous operation resulted in an overflow. 0 The previous operation did not result in an overflow. The value of this bit is only meaningful when accessing PSR or APSR. 27 Q RW 0 APSR DSP Overflow and Saturation Flag Value Description 1 DSP Overflow or saturation has occurred when using a SIMD instruction. 0 DSP overflow or saturation has not occurred since reset or since the bit was last cleared. The value of this bit is only meaningful when accessing PSR or APSR. This bit is cleared by software using an MRS instruction. June 18, 2014 93 Texas Instruments-Production Data The Cortex-M4F Processor Bit/Field Name Type Reset 26:25 ICI / IT RO 0x0 Description EPSR ICI / IT status These bits, along with bits 15:10, contain the Interruptible-Continuable Instruction (ICI) field for an interrupted load multiple or store multiple instruction or the execution state bits of the IT instruction. When EPSR holds the ICI execution state, bits 26:25 are zero. The If-Then block contains up to four instructions following an IT instruction. Each instruction in the block is conditional. The conditions for the instructions are either all the same, or some can be the inverse of others. See the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information. The value of this field is only meaningful when accessing PSR or EPSR. Note that these EPSR bits cannot be accessed using MRS and MSR instructions but the definitions are provided to allow the stacked (E)PSR value to be decoded within an exception handler. 24 THUMB RO 1 EPSR Thumb State This bit indicates the Thumb state and should always be set. The following can clear the THUMB bit: ■ The BLX, BX and POP{PC} instructions ■ Restoration from the stacked xPSR value on an exception return ■ Bit 0 of the vector value on an exception entry or reset Attempting to execute instructions when this bit is clear results in a fault or lockup. See “Lockup” on page 125 for more information. The value of this bit is only meaningful when accessing PSR or EPSR. 23:20 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19:16 GE RW 0x0 Greater Than or Equal Flags See the description of the SEL instruction in the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information. The value of this field is only meaningful when accessing PSR or APSR. 94 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 15:10 ICI / IT RO 0x0 Description EPSR ICI / IT status These bits, along with bits 26:25, contain the Interruptible-Continuable Instruction (ICI) field for an interrupted load multiple or store multiple instruction or the execution state bits of the IT instruction. When an interrupt occurs during the execution of an LDM, STM, PUSH POP, VLDM, VSTM, VPUSH, or VPOP instruction, the processor stops the load multiple or store multiple instruction operation temporarily and stores the next register operand in the multiple operation to bits 15:12. After servicing the interrupt, the processor returns to the register pointed to by bits 15:12 and resumes execution of the multiple load or store instruction. When EPSR holds the ICI execution state, bits 11:10 are zero. The If-Then block contains up to four instructions following a 16-bit IT instruction. Each instruction in the block is conditional. The conditions for the instructions are either all the same, or some can be the inverse of others. See the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information. The value of this field is only meaningful when accessing PSR or EPSR. 9:8 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7:0 ISRNUM RO 0x00 IPSR ISR Number This field contains the exception type number of the current Interrupt Service Routine (ISR). Value Description 0x00 Thread mode 0x01 Reserved 0x02 NMI 0x03 Hard fault 0x04 Memory management fault 0x05 Bus fault 0x06 Usage fault 0x07-0x0A Reserved 0x0B SVCall 0x0C Reserved for Debug 0x0D Reserved 0x0E PendSV 0x0F SysTick 0x10 Interrupt Vector 0 0x11 Interrupt Vector 1 ... ... 0x81 Interrupt Vector 113 See “Exception Types” on page 114 for more information. The value of this field is only meaningful when accessing PSR or IPSR. June 18, 2014 95 Texas Instruments-Production Data The Cortex-M4F Processor Register 18: Priority Mask Register (PRIMASK) The PRIMASK register prevents activation of all exceptions with programmable priority. Reset, non-maskable interrupt (NMI), and hard fault are the only exceptions with fixed priority. Exceptions should be disabled when they might impact the timing of critical tasks. This register is only accessible in privileged mode. The MSR and MRS instructions are used to access the PRIMASK register, and the CPS instruction may be used to change the value of the PRIMASK register. See the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information on these instructions. For more information on exception priority levels, see “Exception Types” on page 114. Priority Mask Register (PRIMASK) Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 PRIMASK RW 0 RO 0 PRIMASK RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Priority Mask Value Description 1 Prevents the activation of all exceptions with configurable priority. 0 No effect. 96 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: Fault Mask Register (FAULTMASK) The FAULTMASK register prevents activation of all exceptions except for the Non-Maskable Interrupt (NMI). Exceptions should be disabled when they might impact the timing of critical tasks. This register is only accessible in privileged mode. The MSR and MRS instructions are used to access the FAULTMASK register, and the CPS instruction may be used to change the value of the FAULTMASK register. See the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information on these instructions. For more information on exception priority levels, see “Exception Types” on page 114. Fault Mask Register (FAULTMASK) Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 FAULTMASK RW 0 RO 0 FAULTMASK RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Fault Mask Value Description 1 Prevents the activation of all exceptions except for NMI. 0 No effect. The processor clears the FAULTMASK bit on exit from any exception handler except the NMI handler. June 18, 2014 97 Texas Instruments-Production Data The Cortex-M4F Processor Register 20: Base Priority Mask Register (BASEPRI) The BASEPRI register defines the minimum priority for exception processing. When BASEPRI is set to a nonzero value, it prevents the activation of all exceptions with the same or lower priority level as the BASEPRI value. Exceptions should be disabled when they might impact the timing of critical tasks. This register is only accessible in privileged mode. For more information on exception priority levels, see “Exception Types” on page 114. Base Priority Mask Register (BASEPRI) Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset BASEPRI RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:5 BASEPRI RW 0x0 RW 0 reserved RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Base Priority Any exception that has a programmable priority level with the same or lower priority as the value of this field is masked. The PRIMASK register can be used to mask all exceptions with programmable priority levels. Higher priority exceptions have lower priority levels. Value Description 4:0 reserved RO 0x0 0x0 All exceptions are unmasked. 0x1 All exceptions with priority level 1-7 are masked. 0x2 All exceptions with priority level 2-7 are masked. 0x3 All exceptions with priority level 3-7 are masked. 0x4 All exceptions with priority level 4-7 are masked. 0x5 All exceptions with priority level 5-7 are masked. 0x6 All exceptions with priority level 6-7 are masked. 0x7 All exceptions with priority level 7 are masked. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 98 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 21: Control Register (CONTROL) The CONTROL register controls the stack used and the privilege level for software execution when the processor is in Thread mode, and indicates whether the FPU state is active. This register is only accessible in privileged mode. Handler mode always uses the MSP, so the processor ignores explicit writes to the ASP bit of the CONTROL register when in Handler mode. The exception entry and return mechanisms automatically update the CONTROL register based on the EXC_RETURN value (see Table 2-10 on page 123). In an OS environment, threads running in Thread mode should use the process stack and the kernel and exception handlers should use the main stack. By default, Thread mode uses the MSP. To switch the stack pointer used in Thread mode to the PSP, either use the MSR instruction to set the ASP bit, as detailed in the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A), or perform an exception return to Thread mode with the appropriate EXC_RETURN value, as shown in Table 2-10 on page 123. Note: When changing the stack pointer, software must use an ISB instruction immediately after the MSR instruction, ensuring that instructions after the ISB execute use the new stack pointer. See the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A). Control Register (CONTROL) Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 FPCA ASP TMPL RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:3 reserved RO 0x0000.000 2 FPCA RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Floating-Point Context Active Value Description 1 Floating-point context active 0 No floating-point context active The Cortex-M4F uses this bit to determine whether to preserve floating-point state when processing an exception. Important: Two bits control when FPCA can be enabled: the ASPEN bit in the Floating-Point Context Control (FPCC) register and the DISFPCA bit in the Auxiliary Control (ACTLR) register. June 18, 2014 99 Texas Instruments-Production Data The Cortex-M4F Processor Bit/Field Name Type Reset 1 ASP RW 0 Description Active Stack Pointer Value Description 1 The PSP is the current stack pointer. 0 The MSP is the current stack pointer In Handler mode, this bit reads as zero and ignores writes. The Cortex-M4F updates this bit automatically on exception return. 0 TMPL RW 0 Thread Mode Privilege Level Value Description 1 Unprivileged software can be executed in Thread mode. 0 Only privileged software can be executed in Thread mode. 100 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 22: Floating-Point Status Control (FPSC) The FPSC register provides all necessary user-level control of the floating-point system. Floating-Point Status Control (FPSC) Type RW, reset 31 Type Reset 30 29 28 27 26 25 24 22 21 20 19 RMODE 18 17 16 N Z C V reserved AHP DN FZ RW - RW - RW - RW - RO 0 RW - RW - RW - RW - RW - RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 IXC UFC OFC DZC IOC RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW - RW - RW - RW - RW - reserved Type Reset 23 IDC RO 0 Bit/Field Name Type Reset 31 N RW - RW - reserved reserved RO 0 RO 0 Description Negative Condition Code Flag Floating-point comparison operations update this condition code flag. 30 Z RW - Zero Condition Code Flag Floating-point comparison operations update this condition code flag. 29 C RW - Carry Condition Code Flag Floating-point comparison operations update this condition code flag. 28 V RW - Overflow Condition Code Flag Floating-point comparison operations update this condition code flag. 27 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 26 AHP RW - Alternative Half-Precision When set, alternative half-precision format is selected. When clear, IEEE half-precision format is selected. The AHP bit in the FPDSC register holds the default value for this bit. 25 DN RW - Default NaN Mode When set, any operation involving one or more NaNs returns the Default NaN. When clear, NaN operands propagate through to the output of a floating-point operation. The DN bit in the FPDSC register holds the default value for this bit. 24 FZ RW - Flush-to-Zero Mode When set, Flush-to-Zero mode is enabled. When clear, Flush-to-Zero mode is disabled and the behavior of the floating-point system is fully compliant with the IEEE 754 standard. The FZ bit in the FPDSC register holds the default value for this bit. June 18, 2014 101 Texas Instruments-Production Data The Cortex-M4F Processor Bit/Field Name Type Reset 23:22 RMODE RW - Description Rounding Mode The specified rounding mode is used by almost all floating-point instructions. The RMODE bit in the FPDSC register holds the default value for this bit. Value Description 21:8 reserved RO 0x0 7 IDC RW - 0x0 Round to Nearest (RN) mode 0x1 Round towards Plus Infinity (RP) mode 0x2 Round towards Minus Infinity (RM) mode 0x3 Round towards Zero (RZ) mode Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Input Denormal Cumulative Exception When set, indicates this exception has occurred since 0 was last written to this bit. 6:5 reserved RO 0x0 4 IXC RW - Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Inexact Cumulative Exception When set, indicates this exception has occurred since 0 was last written to this bit. 3 UFC RW - Underflow Cumulative Exception When set, indicates this exception has occurred since 0 was last written to this bit. 2 OFC RW - Overflow Cumulative Exception When set, indicates this exception has occurred since 0 was last written to this bit. 1 DZC RW - Division by Zero Cumulative Exception When set, indicates this exception has occurred since 0 was last written to this bit. 0 IOC RW - Invalid Operation Cumulative Exception When set, indicates this exception has occurred since 0 was last written to this bit. 102 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 2.3.5 Exceptions and Interrupts The Cortex-M4F processor supports interrupts and system exceptions. The processor and the Nested Vectored Interrupt Controller (NVIC) prioritize and handle all exceptions. An exception changes the normal flow of software control. The processor uses Handler mode to handle all exceptions except for reset. See “Exception Entry and Return” on page 120 for more information. The NVIC registers control interrupt handling. See “Nested Vectored Interrupt Controller (NVIC)” on page 136 for more information. 2.3.6 Data Types The Cortex-M4F supports 32-bit words, 16-bit halfwords, and 8-bit bytes. The processor also supports 64-bit data transfer instructions. All instruction and data memory accesses are little endian. See “Memory Regions, Types and Attributes” on page 106 for more information. 2.4 Memory Model This section describes the processor memory map, the behavior of memory accesses, and the bit-banding features. The processor has a fixed memory map that provides up to 4 GB of addressable memory. The memory map for the TM4C1294NCPDT controller is provided in Table 2-4 on page 103. In this manual, register addresses are given as a hexadecimal increment, relative to the module's base address as shown in the memory map. The regions for SRAM and peripherals include bit-band regions. Bit-banding provides atomic operations to bit data (see “Bit-Banding” on page 109). The processor reserves regions of the Private peripheral bus (PPB) address range for core peripheral registers (see “Cortex-M4 Peripherals” on page 134). Note: Within the memory map, attempts to read or write addresses in reserved spaces result in a bus fault. In addition, attempts to write addresses in the flash range also result in a bus fault. Table 2-4. Memory Map Start End Description For details, see page ... 0x0000.0000 0x000F.FFFF On-chip Flash 621 0x0010.0000 0x01FF.FFFF Reserved - 0x0200.0000 0x02FF.FFFF On-chip ROM (16 MB) 602 0x0300.0000 0x1FFF.FFFF Reserved - 0x2000.0000 0x2006.FFFF Bit-banded on-chip SRAM 602 0x2007.0000 0x21FF.FFFF Reserved - 0x2200.0000 0x2234.FFFF Bit-band alias of bit-banded on-chip SRAM starting at 0x2000.0000 602 0x2235.0000 0x3FFF.FFFF Reserved - 0x4000.0000 0x4000.0FFF Watchdog timer 0 1030 0x4000.1000 0x4000.1FFF Watchdog timer 1 1030 0x4000.2000 0x4000.3FFF Reserved - Memory Peripherals June 18, 2014 103 Texas Instruments-Production Data The Cortex-M4F Processor Table 2-4. Memory Map (continued) Start End Description For details, see page ... 0x4000.4000 0x4000.4FFF GPIO Port A 755 0x4000.5000 0x4000.5FFF GPIO Port B 755 0x4000.6000 0x4000.6FFF GPIO Port C 755 0x4000.7000 0x4000.7FFF GPIO Port D 755 0x4000.8000 0x4000.8FFF SSI0 1243 0x4000.9000 0x4000.9FFF SSI1 1243 0x4000.A000 0x4000.AFFF SSI2 1243 0x4000.B000 0x4000.BFFF SSI3 1243 0x4000.C000 0x4000.CFFF UART0 1173 0x4000.D000 0x4000.DFFF UART1 1173 0x4000.E000 0x4000.EFFF UART2 1173 0x4000.F000 0x4000.FFFF UART3 1173 0x4001.0000 0x4001.0FFF UART4 1173 0x4001.1000 0x4001.1FFF UART5 1173 0x4001.2000 0x4001.2FFF UART6 1173 0x4001.3000 0x4001.3FFF UART7 1173 0x4001.4000 0x4001.FFFF Reserved - 0x4002.0FFF I2C 0 1299 0x4002.1FFF I2C 1 1299 0x4002.2000 0x4002.2FFF I2C 2 1299 0x4002.3000 0x4002.3FFF I2C 3 1299 0x4002.4000 0x4002.4FFF GPIO Port E 755 0x4002.5000 0x4002.5FFF GPIO Port F 755 0x4002.6000 0x4002.6FFF GPIO Port G 755 0x4002.7000 0x4002.7FFF GPIO Port H 755 0x4002.8000 0x4002.8FFF PWM 0 1679 0x4002.9000 0x4002.BFFF Reserved - 0x4002.C000 0x4002.CFFF QEI0 1753 0x4002.D000 0x4002.FFFF Reserved - 0x4003.0000 0x4003.0FFF 16/32-bit Timer 0 974 0x4003.1000 0x4003.1FFF 16/32-bit Timer 1 974 0x4003.2000 0x4003.2FFF 16/32-bit Timer 2 974 0x4003.3000 0x4003.3FFF 16/32-bit Timer 3 974 0x4003.4000 0x4003.4FFF 16/32-bit Timer 4 974 0x4003.5000 0x4003.5FFF 16/32-bit Timer 5 974 0x4003.6000 0x4003.7FFF Reserved - 0x4003.8000 0x4003.8FFF ADC0 1073 0x4003.9000 0x4003.9FFF ADC1 1073 0x4003.A000 0x4003.BFFF Reserved - 0x4003.C000 0x4003.CFFF Analog Comparators 1659 Peripherals 0x4002.0000 0x4002.1000 104 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 2-4. Memory Map (continued) Start End Description For details, see page ... 0x4003.D000 0x4003.DFFF GPIO Port J 755 0x4003.E000 0x4003.FFFF Reserved - 0x4004.0000 0x4004.0FFF CAN0 Controller 1375 0x4004.1000 0x4004.1FFF CAN1 Controller 1375 0x4004.2000 0x4004.FFFF Reserved - 0x4005.0000 0x4005.0FFF USB 1646 0x4005.1000 0x4005.7FFF Reserved - 0x4005.8000 0x4005.8FFF GPIO Port A (AHB aperture) 755 0x4005.9000 0x4005.9FFF GPIO Port B (AHB aperture) 755 0x4005.A000 0x4005.AFFF GPIO Port C (AHB aperture) 755 0x4005.B000 0x4005.BFFF GPIO Port D (AHB aperture) 755 0x4005.C000 0x4005.CFFF GPIO Port E (AHB aperture) 755 0x4005.D000 0x4005.DFFF GPIO Port F (AHB aperture) 755 0x4005.E000 0x4005.EFFF GPIO Port G (AHB aperture) 755 0x4005.F000 0x4005.FFFF GPIO Port H (AHB aperture) 755 0x4006.0000 0x4006.0FFF GPIO Port J (AHB aperture) 755 0x4006.1000 0x4006.1FFF GPIO Port K (AHB aperture) 755 0x4006.2000 0x4006.2FFF GPIO Port L (AHB aperture) 755 0x4006.3000 0x4006.3FFF GPIO Port M (AHB aperture) 755 0x4006.4000 0x4006.4FFF GPIO Port N (AHB aperture) 755 0x4006.5000 0x4006.5FFF GPIO Port P (AHB aperture) 755 0x4006.6000 0x4006.6FFF GPIO Port Q (AHB aperture) 755 0x4006.7000 0x400A.EFFF Reserved - 0x400A.F000 0x400A.FFFF EEPROM and Key Locker 621 0x400B.0000 0x400B.7FFF Reserved - 0x400B.8000 0x400B.8FFF I2C 8 1299 0x400B.9000 0x400B.9FFF I2C 1299 0x400B.A000 0x400B.FFFF Reserved - 0x400C.0000 0x400C.0FFF I2C 4 1299 0x400C.1FFF I2C 5 1299 0x400C.2000 0x400C.2FFF I2C 6 1299 0x400C.3000 0x400C.3FFF I2C 7 1299 0x400C.4000 0x400C.FFFF Reserved - 0x400D.0000 0x400D.0FFF EPI 0 856 0x400D.1000 0x400D.FFFF Reserved - 0x400E.0000 0x400E.0FFF 16/32-bit Timer 6 974 0x400E.1000 0x400E.1FFF 16/32-bit Timer 7 974 0x400E.2000 0x400E.BFFF Reserved - 0x400E.C000 0x400E.CFFF Ethernet Controller 1467 0x400E.D000 0x400F.8FFF Reserved - 0x400F.9000 0x400F.9FFF System Exception Module 523 0x400C.1000 9 June 18, 2014 105 Texas Instruments-Production Data The Cortex-M4F Processor Table 2-4. Memory Map (continued) Start End Description For details, see page ... 0x400F.A000 0x400F.BFFF Reserved - 0x400F.C000 0x400F.CFFF Hibernation Module 551 0x400F.D000 0x400F.DFFF Flash memory control 621 0x400F.E000 0x400F.EFFF System control 247 0x400F.F000 0x400F.FFFF µDMA 701 0x4010.0000 0x41FF.FFFF Reserved - 0x4200.0000 0x43FF.FFFF Bit-banded alias of 0x4000.0000 through 0x400F.FFFF - 0x4400.0000 0x4402.FFFF Reserved - 0x4403.0000 0x4403.0FFF CRC Module - 0x4403.1000 0x4403.1FFF Reserved [4 kB] - 0x4403.2000 0x4403.3FFF Reserved [8 kB] - 0x4403.4000 0x4403.EFFF Reserved - 0x4403.F000 0x4403.FFFF Reserved [4 kB] - 0x4404.0000 0x4404.FFFF Reserved [64 kB] - 0x4405.0000 0x4405.3FFF Reserved - 0x4405.4000 0x4405.4FFF EPHY 0 1467 0x4405.5000 0x5FFF.FFFF Reserved - 0x6000.0000 0xDFFF.FFFF EPI0 mapped peripheral and RAM - 0xE000.0000 0xE000.0FFF Instrumentation Trace Macrocell (ITM) 82 0xE000.1000 0xE000.1FFF Data Watchpoint and Trace (DWT) 82 0xE000.2000 0xE000.2FFF Flash Patch and Breakpoint (FPB) 82 0xE000.3000 0xE000.DFFF Reserved - 0xE000.E000 0xE000.EFFF Cortex-M4F Peripherals (SysTick, NVIC, MPU, FPU and SCB) 146 0xE000.F000 0xE003.FFFF Reserved - 0xE004.0000 0xE004.0FFF Trace Port Interface Unit (TPIU) 83 0xE004.1000 0xE004.1FFF Embedded Trace Macrocell (ETM) 82 0xE004.2000 0xFFFF.FFFF Reserved - Private Peripheral Bus 2.4.1 Memory Regions, Types and Attributes The memory map and the programming of the MPU split the memory map into regions. Each region has a defined memory type, and some regions have additional memory attributes. The memory type and attributes determine the behavior of accesses to the region. The memory types are: ■ Normal: The processor can re-order transactions for efficiency and perform speculative reads. ■ Device: The processor preserves transaction order relative to other transactions to Device or Strongly Ordered memory. ■ Strongly Ordered: The processor preserves transaction order relative to all other transactions. 106 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The different ordering requirements for Device and Strongly Ordered memory mean that the memory system can buffer a write to Device memory but must not buffer a write to Strongly Ordered memory. An additional memory attribute is Execute Never (XN), which means the processor prevents instruction accesses. A fault exception is generated only on execution of an instruction executed from an XN region. 2.4.2 Memory System Ordering of Memory Accesses For most memory accesses caused by explicit memory access instructions, the memory system does not guarantee that the order in which the accesses complete matches the program order of the instructions, providing the order does not affect the behavior of the instruction sequence. Normally, if correct program execution depends on two memory accesses completing in program order, software must insert a memory barrier instruction between the memory access instructions (see “Software Ordering of Memory Accesses” on page 108). However, the memory system does guarantee ordering of accesses to Device and Strongly Ordered memory. For two memory access instructions A1 and A2, if both A1 and A2 are accesses to either Device or Strongly Ordered memory, and if A1 occurs before A2 in program order, A1 is always observed before A2. 2.4.3 Behavior of Memory Accesses Table 2-5 on page 107 shows the behavior of accesses to each region in the memory map. See “Memory Regions, Types and Attributes” on page 106 for more information on memory types and the XN attribute. Tiva™ C Series devices may have reserved memory areas within the address ranges shown below (refer to Table 2-4 on page 103 for more information). Table 2-5. Memory Access Behavior Address Range Memory Region Memory Type Execute Never (XN) Description 0x0000.0000 - 0x1FFF.FFFF Code Normal - This executable region is for program code. Data can also be stored here. 0x2000.0000 - 0x3FFF.FFFF SRAM Normal - This executable region is for data. Code can also be stored here. This region includes bit band and bit band alias areas (see Table 2-6 on page 109). 0x4000.0000 - 0x5FFF.FFFF Peripheral Device XN This region includes bit band and bit band alias areas (see Table 2-7 on page 109). 0x6000.0000 - 0x9FFF.FFFF External RAM Normal - This executable region is for data. 0xA000.0000 - 0xDFFF.FFFF External device Device XN This region is for external device memory. 0xE000.0000- 0xE00F.FFFF Private peripheral bus Strongly Ordered XN This region includes the NVIC, system timer, and system control block. 0xE010.0000- 0xFFFF.FFFF Reserved - - - The Code, SRAM, and external RAM regions can hold programs. However, it is recommended that programs always use the Code region because the Cortex-M4F has separate buses that can perform instruction fetches and data accesses simultaneously. The MPU can override the default memory access behavior described in this section. For more information, see “Memory Protection Unit (MPU)” on page 137. The Cortex-M4F prefetches instructions ahead of execution and speculatively prefetches from branch target addresses. June 18, 2014 107 Texas Instruments-Production Data The Cortex-M4F Processor 2.4.4 Software Ordering of Memory Accesses The order of instructions in the program flow does not always guarantee the order of the corresponding memory transactions for the following reasons: ■ The processor can reorder some memory accesses to improve efficiency, providing this does not affect the behavior of the instruction sequence. ■ The processor has multiple bus interfaces. ■ Memory or devices in the memory map have different wait states. ■ Some memory accesses are buffered or speculative. “Memory System Ordering of Memory Accesses” on page 107 describes the cases where the memory system guarantees the order of memory accesses. Otherwise, if the order of memory accesses is critical, software must include memory barrier instructions to force that ordering. The Cortex-M4F has the following memory barrier instructions: ■ The Data Memory Barrier (DMB) instruction ensures that outstanding memory transactions complete before subsequent memory transactions. ■ The Data Synchronization Barrier (DSB) instruction ensures that outstanding memory transactions complete before subsequent instructions execute. ■ The Instruction Synchronization Barrier (ISB) instruction ensures that the effect of all completed memory transactions is recognizable by subsequent instructions. Memory barrier instructions can be used in the following situations: ■ MPU programming – If the MPU settings are changed and the change must be effective on the very next instruction, use a DSB instruction to ensure the effect of the MPU takes place immediately at the end of context switching. – Use an ISB instruction to ensure the new MPU setting takes effect immediately after programming the MPU region or regions, if the MPU configuration code was accessed using a branch or call. If the MPU configuration code is entered using exception mechanisms, then an ISB instruction is not required. ■ Vector table If the program changes an entry in the vector table and then enables the corresponding exception, use a DMB instruction between the operations. The DMB instruction ensures that if the exception is taken immediately after being enabled, the processor uses the new exception vector. ■ Self-modifying code If a program contains self-modifying code, use an ISB instruction immediately after the code modification in the program. The ISB instruction ensures subsequent instruction execution uses the updated program. ■ Memory map switching 108 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller If the system contains a memory map switching mechanism, use a DSB instruction after switching the memory map in the program. The DSB instruction ensures subsequent instruction execution uses the updated memory map. ■ Dynamic exception priority change When an exception priority has to change when the exception is pending or active, use DSB instructions after the change. The change then takes effect on completion of the DSB instruction. Memory accesses to Strongly Ordered memory, such as the System Control Block, do not require the use of DMB instructions. For more information on the memory barrier instructions, see the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A). 2.4.5 Bit-Banding A bit-band region maps each word in a bit-band alias region to a single bit in the bit-band region. The bit-band regions occupy the lowest 1 MB of the SRAM and peripheral memory regions. Accesses to the 32-MB SRAM alias region map to the 1-MB SRAM bit-band region, as shown in Table 2-6 on page 109. Accesses to the 32-MB peripheral alias region map to the 1-MB peripheral bit-band region, as shown in Table 2-7 on page 109. For the specific address range of the bit-band regions, see Table 2-4 on page 103. Note: A word access to the SRAM or the peripheral bit-band alias region maps to a single bit in the SRAM or peripheral bit-band region. A word access to a bit band address results in a word access to the underlying memory, and similarly for halfword and byte accesses. This allows bit band accesses to match the access requirements of the underlying peripheral. Table 2-6. SRAM Memory Bit-Banding Regions Address Range Memory Region Instruction and Data Accesses Start End 0x2000.0000 0x2006.FFFF SRAM bit-band region Direct accesses to this memory range behave as SRAM memory accesses, but this region is also bit addressable through bit-band alias. 0x2200.0000 0x2234.FFFF SRAM bit-band alias Data accesses to this region are remapped to bit band region. A write operation is performed as read-modify-write. Instruction accesses are not remapped. Table 2-7. Peripheral Memory Bit-Banding Regions Address Range Memory Region Instruction and Data Accesses 0x400F.FFFF Peripheral bit-band region Direct accesses to this memory range behave as peripheral memory accesses, but this region is also bit addressable through bit-band alias. 0x43FF.FFFF Peripheral bit-band alias Data accesses to this region are remapped to bit band region. A write operation is performed as read-modify-write. Instruction accesses are not permitted. Start End 0x4000.0000 0x4200.0000 The following formula shows how the alias region maps onto the bit-band region: bit_word_offset = (byte_offset x 32) + (bit_number x 4) June 18, 2014 109 Texas Instruments-Production Data The Cortex-M4F Processor bit_word_addr = bit_band_base + bit_word_offset where: bit_word_offset The position of the target bit in the bit-band memory region. bit_word_addr The address of the word in the alias memory region that maps to the targeted bit. bit_band_base The starting address of the alias region. byte_offset The number of the byte in the bit-band region that contains the targeted bit. bit_number The bit position, 0-7, of the targeted bit. Figure 2-4 on page 111 shows examples of bit-band mapping between the SRAM bit-band alias region and the SRAM bit-band region: ■ The alias word at 0x23FF.FFE0 maps to bit 0 of the bit-band byte at 0x200F.FFFF: 0x23FF.FFE0 = 0x2200.0000 + (0x000F.FFFF*32) + (0*4) ■ The alias word at 0x23FF.FFFC maps to bit 7 of the bit-band byte at 0x200F.FFFF: 0x23FF.FFFC = 0x2200.0000 + (0x000F.FFFF*32) + (7*4) ■ The alias word at 0x2200.0000 maps to bit 0 of the bit-band byte at 0x2000.0000: 0x2200.0000 = 0x2200.0000 + (0*32) + (0*4) ■ The alias word at 0x2200.001C maps to bit 7 of the bit-band byte at 0x2000.0000: 0x2200.001C = 0x2200.0000+ (0*32) + (7*4) 110 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 2-4. Bit-Band Mapping 32-MB Alias Region 0x23FF.FFFC 0x23FF.FFF8 0x23FF.FFF4 0x23FF.FFF0 0x23FF.FFEC 0x23FF.FFE8 0x23FF.FFE4 0x23FF.FFE0 0x2200.001C 0x2200.0018 0x2200.0014 0x2200.0010 0x2200.000C 0x2200.0008 0x2200.0004 0x2200.0000 7 3 1-MB SRAM Bit-Band Region 7 6 5 4 3 2 1 0 7 6 0x200F.FFFF 7 6 5 4 3 2 0x2000.0003 2.4.5.1 5 4 3 2 1 0 7 6 0x200F.FFFE 1 0 7 6 5 4 3 2 5 4 3 2 1 0 6 0x200F.FFFD 1 0 0x2000.0002 7 6 5 4 3 2 0x2000.0001 5 4 2 1 0 1 0 0x200F.FFFC 1 0 7 6 5 4 3 2 0x2000.0000 Directly Accessing an Alias Region Writing to a word in the alias region updates a single bit in the bit-band region. Bit 0 of the value written to a word in the alias region determines the value written to the targeted bit in the bit-band region. Writing a value with bit 0 set writes a 1 to the bit-band bit, and writing a value with bit 0 clear writes a 0 to the bit-band bit. Bits 31:1 of the alias word have no effect on the bit-band bit. Writing 0x01 has the same effect as writing 0xFF. Writing 0x00 has the same effect as writing 0x0E. When reading a word in the alias region, 0x0000.0000 indicates that the targeted bit in the bit-band region is clear and 0x0000.0001 indicates that the targeted bit in the bit-band region is set. 2.4.5.2 Directly Accessing a Bit-Band Region “Behavior of Memory Accesses” on page 107 describes the behavior of direct byte, halfword, or word accesses to the bit-band regions. 2.4.6 Data Storage The processor views memory as a linear collection of bytes numbered in ascending order from zero. For example, bytes 0-3 hold the first stored word, and bytes 4-7 hold the second stored word. Data is stored in little-endian format, with the least-significant byte (lsbyte) of a word stored at the lowest-numbered byte, and the most-significant byte (msbyte) stored at the highest-numbered byte. Figure 2-5 on page 112 illustrates how data is stored. June 18, 2014 111 Texas Instruments-Production Data The Cortex-M4F Processor Figure 2-5. Data Storage Memory 7 Register 0 31 2.4.7 Address A B0 A+1 B1 A+2 B2 A+3 B3 lsbyte 24 23 B3 16 15 B2 8 7 B1 0 B0 msbyte Synchronization Primitives The Cortex-M4F instruction set includes pairs of synchronization primitives which provide a non-blocking mechanism that a thread or process can use to obtain exclusive access to a memory location. Software can use these primitives to perform a guaranteed read-modify-write memory update sequence or for a semaphore mechanism. Note: The available pairs of synchronization primitives are only available for single processor use and should not be used with multi-processor systems. A pair of synchronization primitives consists of: ■ A Load-Exclusive instruction, which is used to read the value of a memory location and requests exclusive access to that location. ■ A Store-Exclusive instruction, which is used to attempt to write to the same memory location and returns a status bit to a register. If this status bit is clear, it indicates that the thread or process gained exclusive access to the memory and the write succeeds; if this status bit is set, it indicates that the thread or process did not gain exclusive access to the memory and no write was performed. The pairs of Load-Exclusive and Store-Exclusive instructions are: ■ The word instructions LDREX and STREX ■ The halfword instructions LDREXH and STREXH ■ The byte instructions LDREXB and STREXB Software must use a Load-Exclusive instruction with the corresponding Store-Exclusive instruction. To perform an exclusive read-modify-write of a memory location, software must: 1. Use a Load-Exclusive instruction to read the value of the location. 2. Modify the value, as required. 3. Use a Store-Exclusive instruction to attempt to write the new value back to the memory location. 4. Test the returned status bit. 112 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller If the status bit is clear, the read-modify-write completed successfully. If the status bit is set, no write was performed, which indicates that the value returned at step 1 might be out of date. The software must retry the entire read-modify-write sequence. Software can use the synchronization primitives to implement a semaphore as follows: 1. Use a Load-Exclusive instruction to read from the semaphore address to check whether the semaphore is free. 2. If the semaphore is free, use a Store-Exclusive to write the claim value to the semaphore address. 3. If the returned status bit from step 2 indicates that the Store-Exclusive succeeded, then the software has claimed the semaphore. However, if the Store-Exclusive failed, another process might have claimed the semaphore after the software performed step 1. The Cortex-M4F includes an exclusive access monitor that tags the fact that the processor has executed a Load-Exclusive instruction. The processor removes its exclusive access tag if: ■ It executes a CLREX instruction. ■ It executes a Store-Exclusive instruction, regardless of whether the write succeeds. ■ An exception occurs, which means the processor can resolve semaphore conflicts between different threads. For more information about the synchronization primitive instructions, see the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A). 2.5 Exception Model The ARM Cortex-M4F processor and the Nested Vectored Interrupt Controller (NVIC) prioritize and handle all exceptions in Handler Mode. The processor state is automatically stored to the stack on an exception and automatically restored from the stack at the end of the Interrupt Service Routine (ISR). The vector is fetched in parallel to the state saving, enabling efficient interrupt entry. The processor supports tail-chaining, which enables back-to-back interrupts to be performed without the overhead of state saving and restoration. Table 2-8 on page 115 lists all exception types. Software can set eight priority levels on seven of these exceptions (system handlers) as well as on 106 interrupts (listed in Table 2-9 on page 116). Priorities on the system handlers are set with the NVIC System Handler Priority n (SYSPRIn) registers. Interrupts are enabled through the NVIC Interrupt Set Enable n (ENn) register and prioritized with the NVIC Interrupt Priority n (PRIn) registers. Priorities can be grouped by splitting priority levels into preemption priorities and subpriorities. All the interrupt registers are described in “Nested Vectored Interrupt Controller (NVIC)” on page 136. Internally, the highest user-programmable priority (0) is treated as fourth priority, after a Reset, Non-Maskable Interrupt (NMI), and a Hard Fault, in that order. Note that 0 is the default priority for all the programmable priorities. Important: After a write to clear an interrupt source, it may take several processor cycles for the NVIC to see the interrupt source deassert. Thus if the interrupt clear is done as the last action in an interrupt handler, it is possible for the interrupt handler to complete while June 18, 2014 113 Texas Instruments-Production Data The Cortex-M4F Processor the NVIC sees the interrupt as still asserted, causing the interrupt handler to be re-entered errantly. This situation can be avoided by either clearing the interrupt source at the beginning of the interrupt handler or by performing a read or write after the write to clear the interrupt source (and flush the write buffer). See “Nested Vectored Interrupt Controller (NVIC)” on page 136 for more information on exceptions and interrupts. 2.5.1 Exception States Each exception is in one of the following states: ■ Inactive. The exception is not active and not pending. ■ Pending. The exception is waiting to be serviced by the processor. An interrupt request from a peripheral or from software can change the state of the corresponding interrupt to pending. ■ Active. An exception that is being serviced by the processor but has not completed. Note: An exception handler can interrupt the execution of another exception handler. In this case, both exceptions are in the active state. ■ Active and Pending. The exception is being serviced by the processor, and there is a pending exception from the same source. 2.5.2 Exception Types The exception types are: ■ Reset. Reset is invoked on power up or a warm reset. The exception model treats reset as a special form of exception. When reset is asserted, the operation of the processor stops, potentially at any point in an instruction. When reset is deasserted, execution restarts from the address provided by the reset entry in the vector table. Execution restarts as privileged execution in Thread mode. ■ NMI. A non-maskable Interrupt (NMI) can be signaled using the NMI signal or triggered by software using the Interrupt Control and State (INTCTRL) register. This exception has the highest priority other than reset. NMI is permanently enabled and has a fixed priority of -2. NMIs cannot be masked or prevented from activation by any other exception or preempted by any exception other than reset. ■ Hard Fault. A hard fault is an exception that occurs because of an error during exception processing, or because an exception cannot be managed by any other exception mechanism. Hard faults have a fixed priority of -1, meaning they have higher priority than any exception with configurable priority. ■ Memory Management Fault. A memory management fault is an exception that occurs because of a memory protection related fault, including access violation and no match. The MPU or the fixed memory protection constraints determine this fault, for both instruction and data memory transactions. This fault is used to abort instruction accesses to Execute Never (XN) memory regions, even if the MPU is disabled. ■ Bus Fault. A bus fault is an exception that occurs because of a memory-related fault for an instruction or data memory transaction such as a prefetch fault or a memory access fault. This fault can be enabled or disabled. 114 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Usage Fault. A usage fault is an exception that occurs because of a fault related to instruction execution, such as: – An undefined instruction – An illegal unaligned access – Invalid state on instruction execution – An error on exception return An unaligned address on a word or halfword memory access or division by zero can cause a usage fault when the core is properly configured. ■ SVCall. A supervisor call (SVC) is an exception that is triggered by the SVC instruction. In an OS environment, applications can use SVC instructions to access OS kernel functions and device drivers. ■ Debug Monitor. This exception is caused by the debug monitor (when not halting). This exception is only active when enabled. This exception does not activate if it is a lower priority than the current activation. ■ PendSV. PendSV is a pendable, interrupt-driven request for system-level service. In an OS environment, use PendSV for context switching when no other exception is active. PendSV is triggered using the Interrupt Control and State (INTCTRL) register. ■ SysTick. A SysTick exception is an exception that the system timer generates when it reaches zero when it is enabled to generate an interrupt. Software can also generate a SysTick exception using the Interrupt Control and State (INTCTRL) register. In an OS environment, the processor can use this exception as system tick. ■ Interrupt (IRQ). An interrupt, or IRQ, is an exception signaled by a peripheral or generated by a software request and fed through the NVIC (prioritized). All interrupts are asynchronous to instruction execution. In the system, peripherals use interrupts to communicate with the processor. Table 2-9 on page 116 lists the interrupts on the TM4C1294NCPDT controller. For an asynchronous exception, other than reset, the processor can execute another instruction between when the exception is triggered and when the processor enters the exception handler. Privileged software can disable the exceptions that Table 2-8 on page 115 shows as having configurable priority (see the SYSHNDCTRL register on page 180 and the DIS0 register on page 155). For more information about hard faults, memory management faults, bus faults, and usage faults, see “Fault Handling” on page 123. Table 2-8. Exception Types Exception Type a Vector Number Priority Vector Address or b Offset - 0 - 0x0000.0000 Stack top is loaded from the first entry of the vector table on reset. Reset 1 -3 (highest) 0x0000.0004 Asynchronous Non-Maskable Interrupt (NMI) 2 -2 0x0000.0008 Asynchronous Hard Fault 3 -1 0x0000.000C - 0x0000.0010 Synchronous Memory Management 4 c programmable June 18, 2014 Activation 115 Texas Instruments-Production Data The Cortex-M4F Processor Table 2-8. Exception Types (continued) Exception Type a Vector Number Priority Bus Fault 5 programmable Usage Fault 6 7-10 - Vector Address or b Offset Activation c 0x0000.0014 Synchronous when precise and asynchronous when imprecise programmable c 0x0000.0018 Synchronous - c c Reserved SVCall 11 programmable 0x0000.002C Synchronous Debug Monitor 12 programmable 0x0000.0030 Synchronous - 13 - 0x0000.0038 Asynchronous c 0x0000.003C Asynchronous PendSV 14 programmable SysTick 15 programmable Interrupts 16 and above Reserved c d programmable 0x0000.0040 and above Asynchronous a. 0 is the default priority for all the programmable priorities. b. See “Vector Table” on page 119. c. See SYSPRI1 on page 177. d. See PRIn registers on page 159. Table 2-9. Interrupts Vector Number Interrupt Number (Bit in Interrupt Registers) Vector Address or Offset Description 0-15 - 0x0000.0000 0x0000.003C 16 0 0x0000.0040 GPIO Port A 17 1 0x0000.0044 GPIO Port B 18 2 0x0000.0048 GPIO Port C 19 3 0x0000.004C GPIO Port D 20 4 0x0000.0050 GPIO Port E 21 5 0x0000.0054 UART0 22 6 0x0000.0058 UART1 23 7 0x0000.005C SSI0 24 8 0x0000.0060 I2C0 25 9 0x0000.0064 PWM Fault 26 10 0x0000.0068 PWM Generator 0 27 11 0x0000.006C PWM Generator 1 28 12 0x0000.0070 PWM Generator 2 29 13 0x0000.0074 QEI0 30 14 0x0000.0078 ADC0 Sequence 0 31 15 0x0000.007C ADC0 Sequence 1 32 16 0x0000.0080 ADC0 Sequence 2 33 17 0x0000.0084 ADC0 Sequence 3 34 18 0x0000.0088 Watchdog Timers 0 and 1 35 19 0x0000.008C 16/32-Bit Timer 0A 36 20 0x0000.0090 16/32-Bit Timer 0B 37 21 0x0000.0094 16/32-Bit Timer 1A Processor exceptions 116 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 2-9. Interrupts (continued) Vector Number Interrupt Number (Bit in Interrupt Registers) Vector Address or Offset Description 38 22 0x0000.0098 16/32-Bit Timer 1B 39 23 0x0000.009C 16/32-Bit Timer 2A 40 24 0x0000.00A0 16/32-Bit Timer 2B 41 25 0x0000.00A4 Analog Comparator 0 42 26 0x0000.00A8 Analog Comparator 1 43 27 0x0000.00AC Analog Comparator 2 44 28 0x0000.00B0 System Control 45 29 0x0000.00B4 Flash Memory Control 46 30 0x0000.00B8 GPIO Port F 47 31 0x0000.00BC GPIO Port G 48 32 0x0000.00C0 GPIO Port H 49 33 0x0000.00C4 UART2 50 34 0x0000.00C8 SSI1 51 35 0x0000.00CC 16/32-Bit Timer 3A 52 36 0x0000.00D0 16/32-Bit Timer 3B 53 37 0x0000.00D4 I2C1 54 38 0x0000.00D8 CAN 0 55 39 0x0000.00DC CAN1 56 40 0x0000.00E0 Ethernet MAC 57 41 0x0000.00E4 HIB 58 42 0x0000.00E8 USB MAC 59 43 0x0000.00EC PWM Generator 3 60 44 0x0000.00F0 uDMA 0 Software 61 45 0x0000.00F4 uDMA 0 Error 62 46 0x0000.00F8 ADC1 Sequence 0 63 47 0x0000.00FC ADC1 Sequence 1 64 48 0x0000.0100 ADC1 Sequence 2 65 49 0x0000.0104 ADC1 Sequence 3 66 50 0x0000.0108 EPI 0 67 51 0x0000.010C GPIO Port J 68 52 0x0000.0110 GPIO Port K 69 53 0x0000.0114 GPIO Port L 70 54 0x0000.0118 SSI 2 71 55 0x0000.011C SSI 3 72 56 0x0000.0120 UART 3 73 57 0x0000.0124 UART 4 74 58 0x0000.0128 UART 5 75 59 0x0000.012C UART 6 76 60 0x0000.0130 UART 7 77 61 0x0000.0134 I2C 2 78 62 0x0000.0138 I2C 3 June 18, 2014 117 Texas Instruments-Production Data The Cortex-M4F Processor Table 2-9. Interrupts (continued) Vector Number Interrupt Number (Bit in Interrupt Registers) Vector Address or Offset Description 79 63 0x0000.013C Timer 4A 80 64 0x0000.0140 Timer 4B 81 65 0x0000.0144 Timer 5A 82 66 0x0000.0148 Timer 5B 83 67 0x0000.014C Floating-Point Exception (imprecise) 84-85 68-69 - 86 70 0x0000.0158 I2C 4 87 71 0x0000.015C I2C 5 88 72 0x0000.0160 GPIO Port M 89 73 0x0000.0164 GPIO Port N 90 74 - 91 75 0x0000.016C 92 76 0x0000.017 Reserved Reserved Tamper GPIO Port P (Summary or P0) 93 77 0x0000.0174 GPIO Port P1 94 78 0x0000.0178 GPIO Port P2 95 79 0x0000.017C GPIO Port P3 96 80 0x0000.0180 GPIO Port P4 97 81 0x0000.0184 GPIO Port P5 98 82 0x0000.0188 GPIO Port P6 99 83 0x0000.018C GPIO Port P7 100 84 0x0000.0190 GPIO Port Q (Summary or Q0) 101 85 0x0000.0194 GPIO Port Q1 102 86 0x0000.0198 GPIO Port Q2 103 87 0x0000.019C GPIO Port Q3 104 88 0x0000.01A0 GPIO Port Q4 105 89 0x0000.01A4 GPIO Port Q5 106 90 0x0000.01A8 GPIO Port Q6 GPIO Port Q7 107 91 0x0000.01AC 108-113 92-97 - 114 98 0x0000.01C8 16/32-Bit Timer 6A 115 99 0x0000.01CC 16/32-Bit Timer 6B 116 100 0x0000.01D0 16/32-Bit Timer 7A 117 101 0x0000.01D4 16/32-Bit Timer 7B 118 102 0x0000.01D8 I2C 6 119 103 0x0000.01DC I2C 7 120-124 104-108 - 125 109 0x0000.01F4 I2C 8 126 110 0x0000.01F8 I2C 9 127-129 111-113 - Reserved Reserved Reserved 118 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 2.5.3 Exception Handlers The processor handles exceptions using: ■ Interrupt Service Routines (ISRs). Interrupts (IRQx) are the exceptions handled by ISRs. ■ Fault Handlers. Hard fault, memory management fault, usage fault, and bus fault are fault exceptions handled by the fault handlers. ■ System Handlers. NMI, PendSV, SVCall, SysTick, and the fault exceptions are all system exceptions that are handled by system handlers. 2.5.4 Vector Table The vector table contains the reset value of the stack pointer and the start addresses, also called exception vectors, for all exception handlers. The vector table is constructed using the vector address or offset shown in Table 2-8 on page 115. Figure 2-6 on page 119 shows the order of the exception vectors in the vector table. The least-significant bit of each vector must be 1, indicating that the exception handler is Thumb code Figure 2-6. Vector Table Exception number IRQ number Offset 0x040 + 0x(N*4) . . . 0x004C Vector 2 0x0048 IRQ2 17 1 0x0044 IRQ1 16 0 0x0040 IRQ0 15 -1 0x003C Systick 14 -2 0x0038 PendSV (N+16) (N) . . . 18 IRQ N . . . 13 Reserved 12 Reserved for Debug 11 -5 0x002C SVCall 10 9 Reserved 8 7 6 -10 0x0018 Usage fault 5 -11 0x0014 Bus fault 4 -12 0x0010 Memory management fault 3 -13 0x000C 2 -14 0x0008 NMI 1 0x0004 Reset 0 0x0000 Initial SP value Hard fault On system reset, the vector table is fixed at address 0x0000.0000. Privileged software can write to the Vector Table Offset (VTABLE) register to relocate the vector table start address to a different June 18, 2014 119 Texas Instruments-Production Data The Cortex-M4F Processor memory location, in the range 0x0000.0400 to 0x3FFF.FC00 (see “Vector Table” on page 119). Note that when configuring the VTABLE register, the offset must be aligned on a 1024-byte boundary. 2.5.5 Exception Priorities As Table 2-8 on page 115 shows, all exceptions have an associated priority, with a lower priority value indicating a higher priority and configurable priorities for all exceptions except Reset, Hard fault, and NMI. If software does not configure any priorities, then all exceptions with a configurable priority have a priority of 0. For information about configuring exception priorities, see page 177 and page 159. Note: Configurable priority values for the Tiva™ C Series implementation are in the range 0-7. This means that the Reset, Hard fault, and NMI exceptions, with fixed negative priority values, always have higher priority than any other exception. For example, assigning a higher priority value to IRQ[0] and a lower priority value to IRQ[1] means that IRQ[1] has higher priority than IRQ[0]. If both IRQ[1] and IRQ[0] are asserted, IRQ[1] is processed before IRQ[0]. If multiple pending exceptions have the same priority, the pending exception with the lowest exception number takes precedence. For example, if both IRQ[0] and IRQ[1] are pending and have the same priority, then IRQ[0] is processed before IRQ[1]. When the processor is executing an exception handler, the exception handler is preempted if a higher priority exception occurs. If an exception occurs with the same priority as the exception being handled, the handler is not preempted, irrespective of the exception number. However, the status of the new interrupt changes to pending. 2.5.6 Interrupt Priority Grouping To increase priority control in systems with interrupts, the NVIC supports priority grouping. This grouping divides each interrupt priority register entry into two fields: ■ An upper field that defines the group priority ■ A lower field that defines a subpriority within the group Only the group priority determines preemption of interrupt exceptions. When the processor is executing an interrupt exception handler, another interrupt with the same group priority as the interrupt being handled does not preempt the handler. If multiple pending interrupts have the same group priority, the subpriority field determines the order in which they are processed. If multiple pending interrupts have the same group priority and subpriority, the interrupt with the lowest IRQ number is processed first. For information about splitting the interrupt priority fields into group priority and subpriority, see page 171. 2.5.7 Exception Entry and Return Descriptions of exception handling use the following terms: ■ Preemption. When the processor is executing an exception handler, an exception can preempt the exception handler if its priority is higher than the priority of the exception being handled. See “Interrupt Priority Grouping” on page 120 for more information about preemption by an interrupt. When one exception preempts another, the exceptions are called nested exceptions. See “Exception Entry” on page 121 more information. 120 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Return. Return occurs when the exception handler is completed, and there is no pending exception with sufficient priority to be serviced and the completed exception handler was not handling a late-arriving exception. The processor pops the stack and restores the processor state to the state it had before the interrupt occurred. See “Exception Return” on page 122 for more information. ■ Tail-Chaining. This mechanism speeds up exception servicing. On completion of an exception handler, if there is a pending exception that meets the requirements for exception entry, the stack pop is skipped and control transfers to the new exception handler. ■ Late-Arriving. This mechanism speeds up preemption. If a higher priority exception occurs during state saving for a previous exception, the processor switches to handle the higher priority exception and initiates the vector fetch for that exception. State saving is not affected by late arrival because the state saved is the same for both exceptions. Therefore, the state saving continues uninterrupted. The processor can accept a late arriving exception until the first instruction of the exception handler of the original exception enters the execute stage of the processor. On return from the exception handler of the late-arriving exception, the normal tail-chaining rules apply. 2.5.7.1 Exception Entry Exception entry occurs when there is a pending exception with sufficient priority and either the processor is in Thread mode or the new exception is of higher priority than the exception being handled, in which case the new exception preempts the original exception. When one exception preempts another, the exceptions are nested. Sufficient priority means the exception has more priority than any limits set by the mask registers (see PRIMASK on page 96, FAULTMASK on page 97, and BASEPRI on page 98). An exception with less priority than this is pending but is not handled by the processor. When the processor takes an exception, unless the exception is a tail-chained or a late-arriving exception, the processor pushes information onto the current stack. This operation is referred to as stacking and the structure of eight data words is referred to as stack frame. When using floating-point routines, the Cortex-M4F processor automatically stacks the architected floating-point state on exception entry. Figure 2-7 on page 122 shows the Cortex-M4F stack frame layout when floating-point state is preserved on the stack as the result of an interrupt or an exception. Note: Where stack space for floating-point state is not allocated, the stack frame is the same as that of ARMv7-M implementations without an FPU. Figure 2-7 on page 122 shows this stack frame also. June 18, 2014 121 Texas Instruments-Production Data The Cortex-M4F Processor Figure 2-7. Exception Stack Frame ... {aligner} FPSCR S15 S14 S13 S12 S11 S10 S9 S8 S7 S6 S5 S4 S3 S2 S1 S0 xPSR PC LR R12 R3 R2 R1 R0 Exception frame with floating-point storage Pre-IRQ top of stack Decreasing memory address IRQ top of stack ... {aligner} xPSR PC LR R12 R3 R2 R1 R0 Pre-IRQ top of stack IRQ top of stack Exception frame without floating-point storage Immediately after stacking, the stack pointer indicates the lowest address in the stack frame. The stack frame includes the return address, which is the address of the next instruction in the interrupted program. This value is restored to the PC at exception return so that the interrupted program resumes. In parallel with the stacking operation, the processor performs a vector fetch that reads the exception handler start address from the vector table. When stacking is complete, the processor starts executing the exception handler. At the same time, the processor writes an EXC_RETURN value to the LR, indicating which stack pointer corresponds to the stack frame and what operation mode the processor was in before the entry occurred. If no higher-priority exception occurs during exception entry, the processor starts executing the exception handler and automatically changes the status of the corresponding pending interrupt to active. If another higher-priority exception occurs during exception entry, known as late arrival, the processor starts executing the exception handler for this exception and does not change the pending status of the earlier exception. 2.5.7.2 Exception Return Exception return occurs when the processor is in Handler mode and executes one of the following instructions to load the EXC_RETURN value into the PC: 122 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ An LDM or POP instruction that loads the PC ■ A BX instruction using any register ■ An LDR instruction with the PC as the destination EXC_RETURN is the value loaded into the LR on exception entry. The exception mechanism relies on this value to detect when the processor has completed an exception handler. The lowest five bits of this value provide information on the return stack and processor mode. Table 2-10 on page 123 shows the EXC_RETURN values with a description of the exception return behavior. EXC_RETURN bits 31:5 are all set. When this value is loaded into the PC, it indicates to the processor that the exception is complete, and the processor initiates the appropriate exception return sequence. Table 2-10. Exception Return Behavior EXC_RETURN[31:0] Description 0xFFFF.FFE0 Reserved 0xFFFF.FFE1 Return to Handler mode. Exception return uses floating-point state from MSP. Execution uses MSP after return. 0xFFFF.FFE2 - 0xFFFF.FFE8 Reserved 0xFFFF.FFE9 Return to Thread mode. Exception return uses floating-point state from MSP. Execution uses MSP after return. 0xFFFF.FFEA - 0xFFFF.FFEC Reserved 0xFFFF.FFED Return to Thread mode. Exception return uses floating-point state from PSP. Execution uses PSP after return. 0xFFFF.FFEE - 0xFFFF.FFF0 Reserved 0xFFFF.FFF1 Return to Handler mode. Exception return uses non-floating-point state from MSP. Execution uses MSP after return. 0xFFFF.FFF2 - 0xFFFF.FFF8 Reserved 0xFFFF.FFF9 Return to Thread mode. Exception return uses non-floating-point state from MSP. Execution uses MSP after return. 0xFFFF.FFFA - 0xFFFF.FFFC Reserved 0xFFFF.FFFD Return to Thread mode. Exception return uses non-floating-point state from PSP. Execution uses PSP after return. 0xFFFF.FFFE - 0xFFFF.FFFF 2.6 Reserved Fault Handling Faults are a subset of the exceptions (see “Exception Model” on page 113). The following conditions generate a fault: ■ A bus error on an instruction fetch or vector table load or a data access. June 18, 2014 123 Texas Instruments-Production Data The Cortex-M4F Processor ■ An internally detected error such as an undefined instruction or an attempt to change state with a BX instruction. ■ Attempting to execute an instruction from a memory region marked as Non-Executable (XN). ■ An MPU fault because of a privilege violation or an attempt to access an unmanaged region. 2.6.1 Fault Types Table 2-11 on page 124 shows the types of fault, the handler used for the fault, the corresponding fault status register, and the register bit that indicates the fault has occurred. See page 184 for more information about the fault status registers. Table 2-11. Faults Fault Handler Fault Status Register Bit Name Bus error on a vector read Hard fault Hard Fault Status (HFAULTSTAT) VECT Fault escalated to a hard fault Hard fault Hard Fault Status (HFAULTSTAT) FORCED MPU or default memory mismatch on instruction access Memory management fault Memory Management Fault Status (MFAULTSTAT) IERR MPU or default memory mismatch on data access Memory management fault Memory Management Fault Status (MFAULTSTAT) DERR MPU or default memory mismatch on exception stacking Memory management fault Memory Management Fault Status (MFAULTSTAT) MSTKE MPU or default memory mismatch on exception unstacking Memory management fault Memory Management Fault Status (MFAULTSTAT) MUSTKE MPU or default memory mismatch during lazy floating-point state preservation Memory management fault Memory Management Fault Status (MFAULTSTAT) MLSPERR Bus error during exception stacking Bus fault Bus Fault Status (BFAULTSTAT) BSTKE Bus error during exception unstacking Bus fault Bus Fault Status (BFAULTSTAT) BUSTKE Bus error during instruction prefetch Bus fault Bus Fault Status (BFAULTSTAT) IBUS Bus error during lazy floating-point state Bus fault preservation Bus Fault Status (BFAULTSTAT) BLSPE Precise data bus error Bus fault Bus Fault Status (BFAULTSTAT) PRECISE Imprecise data bus error Bus fault Bus Fault Status (BFAULTSTAT) IMPRE Attempt to access a coprocessor Usage fault Usage Fault Status (UFAULTSTAT) NOCP Undefined instruction Usage fault Usage Fault Status (UFAULTSTAT) UNDEF Attempt to enter an invalid instruction b set state Usage fault Usage Fault Status (UFAULTSTAT) INVSTAT Invalid EXC_RETURN value Usage fault Usage Fault Status (UFAULTSTAT) INVPC Illegal unaligned load or store Usage fault Usage Fault Status (UFAULTSTAT) UNALIGN Divide by 0 Usage fault Usage Fault Status (UFAULTSTAT) DIV0 a a. Occurs on an access to an XN region even if the MPU is disabled. b. Attempting to use an instruction set other than the Thumb instruction set, or returning to a non load-store-multiply instruction with ICI continuation. 2.6.2 Fault Escalation and Hard Faults All fault exceptions except for hard fault have configurable exception priority (see SYSPRI1 on page 177). Software can disable execution of the handlers for these faults (see SYSHNDCTRL on page 180). 124 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Usually, the exception priority, together with the values of the exception mask registers, determines whether the processor enters the fault handler, and whether a fault handler can preempt another fault handler as described in “Exception Model” on page 113. In some situations, a fault with configurable priority is treated as a hard fault. This process is called priority escalation, and the fault is described as escalated to hard fault. Escalation to hard fault occurs when: ■ A fault handler causes the same kind of fault as the one it is servicing. This escalation to hard fault occurs because a fault handler cannot preempt itself because it must have the same priority as the current priority level. ■ A fault handler causes a fault with the same or lower priority as the fault it is servicing. This situation happens because the handler for the new fault cannot preempt the currently executing fault handler. ■ An exception handler causes a fault for which the priority is the same as or lower than the currently executing exception. ■ A fault occurs and the handler for that fault is not enabled. If a bus fault occurs during a stack push when entering a bus fault handler, the bus fault does not escalate to a hard fault. Thus if a corrupted stack causes a fault, the fault handler executes even though the stack push for the handler failed. The fault handler operates but the stack contents are corrupted. Note: 2.6.3 Only Reset and NMI can preempt the fixed priority hard fault. A hard fault can preempt any exception other than Reset, NMI, or another hard fault. Fault Status Registers and Fault Address Registers The fault status registers indicate the cause of a fault. For bus faults and memory management faults, the fault address register indicates the address accessed by the operation that caused the fault, as shown in Table 2-12 on page 125. Table 2-12. Fault Status and Fault Address Registers Handler Status Register Name Address Register Name Register Description Hard fault Hard Fault Status (HFAULTSTAT) - page 190 Memory management Memory Management Fault Status fault (MFAULTSTAT) Memory Management Fault Address (MMADDR) page 184 Bus fault Bus Fault Address (FAULTADDR) page 184 - page 184 Bus Fault Status (BFAULTSTAT) Usage fault 2.6.4 Usage Fault Status (UFAULTSTAT) page 191 page 192 Lockup The processor enters a lockup state if a hard fault occurs when executing the NMI or hard fault handlers. When the processor is in the lockup state, it does not execute any instructions. The processor remains in lockup state until it is reset, an NMI occurs, or it is halted by a debugger. Note: If the lockup state occurs from the NMI handler, a subsequent NMI does not cause the processor to leave the lockup state. June 18, 2014 125 Texas Instruments-Production Data The Cortex-M4F Processor 2.7 Power Management The Cortex-M4F processor sleep modes reduce power consumption: ■ Sleep mode stops the processor clock. ■ Deep-sleep mode stops the system clock and switches off the PLL and Flash memory. The SLEEPDEEP bit of the System Control (SYSCTRL) register selects which sleep mode is used (see page 173). For more information about the behavior of the sleep modes, see “System Control” on page 239. This section describes the mechanisms for entering sleep mode and the conditions for waking up from sleep mode, both of which apply to Sleep mode and Deep-sleep mode. 2.7.1 Entering Sleep Modes This section describes the mechanisms software can use to put the processor into one of the sleep modes. The system can generate spurious wake-up events, for example a debug operation wakes up the processor. Therefore, software must be able to put the processor back into sleep mode after such an event. A program might have an idle loop to put the processor back to sleep mode. 2.7.1.1 Wait for Interrupt The wait for interrupt instruction, WFI, causes immediate entry to sleep mode unless the wake-up condition is true (see “Wake Up from WFI or Sleep-on-Exit” on page 127). When the processor executes a WFI instruction, it stops executing instructions and enters sleep mode. See the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information. 2.7.1.2 Wait for Event The wait for event instruction, WFE, causes entry to sleep mode conditional on the value of a one-bit event register. When the processor executes a WFE instruction, it checks the event register. If the register is 0, the processor stops executing instructions and enters sleep mode. If the register is 1, the processor clears the register and continues executing instructions without entering sleep mode. If the event register is 1, the processor must not enter sleep mode on execution of a WFE instruction. Typically, this situation occurs if an SEV instruction has been executed. Software cannot access this register directly. See the Cortex™-M4 instruction set chapter in the ARM® Cortex™-M4 Devices Generic User Guide (literature number ARM DUI 0553A) for more information. 2.7.1.3 Sleep-on-Exit If the SLEEPEXIT bit of the SYSCTRL register is set, when the processor completes the execution of all exception handlers, it returns to Thread mode and immediately enters sleep mode. This mechanism can be used in applications that only require the processor to run when an exception occurs. 2.7.2 Wake Up from Sleep Mode The conditions for the processor to wake up depend on the mechanism that caused it to enter sleep mode. 126 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 2.7.2.1 Wake Up from WFI or Sleep-on-Exit Normally, the processor wakes up only when the NVIC detects an exception with sufficient priority to cause exception entry. Some embedded systems might have to execute system restore tasks after the processor wakes up and before executing an interrupt handler. Entry to the interrupt handler can be delayed by setting the PRIMASK bit and clearing the FAULTMASK bit. If an interrupt arrives that is enabled and has a higher priority than current exception priority, the processor wakes up but does not execute the interrupt handler until the processor clears PRIMASK. For more information about PRIMASK and FAULTMASK, see page 96 and page 97. 2.7.2.2 Wake Up from WFE The processor wakes up if it detects an exception with sufficient priority to cause exception entry. In addition, if the SEVONPEND bit in the SYSCTRL register is set, any new pending interrupt triggers an event and wakes up the processor, even if the interrupt is disabled or has insufficient priority to cause exception entry. For more information about SYSCTRL, see page 173. 2.8 Instruction Set Summary The processor implements a version of the Thumb instruction set. Table 2-13 on page 127 lists the supported instructions. Note: In Table 2-13 on page 127: ■ ■ ■ ■ ■ Angle brackets, , enclose alternative forms of the operand Braces, {}, enclose optional operands The Operands column is not exhaustive Op2 is a flexible second operand that can be either a register or a constant Most instructions can use an optional condition code suffix For more information on the instructions and operands, see the instruction descriptions in the ARM® Cortex™-M4 Technical Reference Manual. Table 2-13. Cortex-M4F Instruction Summary Mnemonic Operands Brief Description Flags ADC, ADCS {Rd,} Rn, Op2 Add with carry N,Z,C,V ADD, ADDS {Rd,} Rn, Op2 Add N,Z,C,V ADD, ADDW {Rd,} Rn , #imm12 Add - ADR Rd, label Load PC-relative address - AND, ANDS {Rd,} Rn, Op2 Logical AND N,Z,C ASR, ASRS Rd, Rm, Arithmetic shift right N,Z,C B label Branch - BFC Rd, #lsb, #width Bit field clear - BFI Rd, Rn, #lsb, #width Bit field insert - BIC, BICS {Rd,} Rn, Op2 Bit clear N,Z,C BKPT #imm Breakpoint - BL label Branch with link - BLX Rm Branch indirect with link - BX Rm Branch indirect - CBNZ Rn, label Compare and branch if non-zero - June 18, 2014 127 Texas Instruments-Production Data The Cortex-M4F Processor Table 2-13. Cortex-M4F Instruction Summary (continued) Mnemonic Operands Brief Description Flags CBZ Rn, label Compare and branch if zero - CLREX - Clear exclusive - CLZ Rd, Rm Count leading zeros - CMN Rn, Op2 Compare negative N,Z,C,V CMP Rn, Op2 Compare N,Z,C,V CPSID i Change processor state, disable interrupts - CPSIE i Change processor state, enable interrupts - DMB - Data memory barrier - DSB - Data synchronization barrier - EOR, EORS {Rd,} Rn, Op2 Exclusive OR N,Z,C ISB - Instruction synchronization barrier - IT - If-Then condition block - LDM Rn{!}, reglist Load multiple registers, increment after - LDMDB, LDMEA Rn{!}, reglist Load multiple registers, decrement before LDMFD, LDMIA Rn{!}, reglist Load multiple registers, increment after - LDR Rt, [Rn, #offset] Load register with word - LDRB, LDRBT Rt, [Rn, #offset] Load register with byte - LDRD Rt, Rt2, [Rn, #offset] Load register with two bytes - LDREX Rt, [Rn, #offset] Load register exclusive - LDREXB Rt, [Rn] Load register exclusive with byte - LDREXH Rt, [Rn] Load register exclusive with halfword - LDRH, LDRHT Rt, [Rn, #offset] Load register with halfword - LDRSB, LDRSBT Rt, [Rn, #offset] Load register with signed byte - LDRSH, LDRSHT Rt, [Rn, #offset] Load register with signed halfword - LDRT Rt, [Rn, #offset] Load register with word - LSL, LSLS Rd, Rm, Logical shift left N,Z,C LSR, LSRS Rd, Rm, Logical shift right N,Z,C MLA Rd, Rn, Rm, Ra Multiply with accumulate, 32-bit result - MLS Rd, Rn, Rm, Ra Multiply and subtract, 32-bit result - MOV, MOVS Rd, Op2 Move N,Z,C MOV, MOVW Rd, #imm16 Move 16-bit constant N,Z,C MOVT Rd, #imm16 Move top - MRS Rd, spec_reg Move from special register to general register - MSR spec_reg, Rm Move from general register to special register N,Z,C,V MUL, MULS {Rd,} Rn, Rm Multiply, 32-bit result N,Z MVN, MVNS Rd, Op2 Move NOT N,Z,C NOP - No operation - ORN, ORNS {Rd,} Rn, Op2 Logical OR NOT N,Z,C 128 - June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 2-13. Cortex-M4F Instruction Summary (continued) Mnemonic Operands Brief Description Flags ORR, ORRS {Rd,} Rn, Op2 Logical OR N,Z,C PKHTB, PKHBT {Rd,} Rn, Rm, Op2 Pack halfword - POP reglist Pop registers from stack - PUSH reglist Push registers onto stack - QADD {Rd,} Rn, Rm Saturating add Q QADD16 {Rd,} Rn, Rm Saturating add 16 - QADD8 {Rd,} Rn, Rm Saturating add 8 - QASX {Rd,} Rn, Rm Saturating add and subtract with exchange - QDADD {Rd,} Rn, Rm Saturating double and add Q QDSUB {Rd,} Rn, Rm Saturating double and subtract Q QSAX {Rd,} Rn, Rm Saturating subtract and add with exchange - QSUB {Rd,} Rn, Rm Saturating subtract Q QSUB16 {Rd,} Rn, Rm Saturating subtract 16 - QSUB8 {Rd,} Rn, Rm Saturating subtract 8 - RBIT Rd, Rn Reverse bits - REV Rd, Rn Reverse byte order in a word - REV16 Rd, Rn Reverse byte order in each halfword - REVSH Rd, Rn Reverse byte order in bottom halfword and sign extend - ROR, RORS Rd, Rm, Rotate right N,Z,C RRX, RRXS Rd, Rm Rotate right with extend N,Z,C RSB, RSBS {Rd,} Rn, Op2 Reverse subtract N,Z,C,V SADD16 {Rd,} Rn, Rm Signed add 16 GE SADD8 {Rd,} Rn, Rm Signed add 8 GE SASX {Rd,} Rn, Rm Signed add and subtract with exchange GE SBC, SBCS {Rd,} Rn, Op2 Subtract with carry N,Z,C,V SBFX Rd, Rn, #lsb, #width Signed bit field extract - SDIV {Rd,} Rn, Rm Signed divide - SEL {Rd,} Rn, Rm Select bytes - SEV - Send event - SHADD16 {Rd,} Rn, Rm Signed halving add 16 - SHADD8 {Rd,} Rn, Rm Signed halving add 8 - SHASX {Rd,} Rn, Rm Signed halving add and subtract with exchange - SHSAX {Rd,} Rn, Rm Signed halving add and subtract with exchange - SHSUB16 {Rd,} Rn, Rm Signed halving subtract 16 - SHSUB8 {Rd,} Rn, Rm Signed halving subtract 8 - June 18, 2014 129 Texas Instruments-Production Data The Cortex-M4F Processor Table 2-13. Cortex-M4F Instruction Summary (continued) Mnemonic Operands Brief Description Flags SMLABB, Rd, Rn, Rm, Ra Signed multiply accumulate long (halfwords) Q Rd, Rn, Rm, Ra Signed multiply accumulate dual Q SMLAL RdLo, RdHi, Rn, Rm Signed multiply with accumulate (32x32+64), 64-bit result - SMLALBB, RdLo, RdHi, Rn, Rm Signed multiply accumulate long (halfwords) - SMLALD, SMLALDX RdLo, RdHi, Rn, Rm Signed multiply accumulate long dual - SMLAWB,SMLAWT Rd, Rn, Rm, Ra Signed multiply accumulate, word by halfword Q SMLSD Rd, Rn, Rm, Ra Signed multiply subtract dual Q RdLo, RdHi, Rn, Rm Signed multiply subtract long dual SMMLA Rd, Rn, Rm, Ra Signed most significant word multiply accumulate - SMMLS, Rd, Rn, Rm, Ra Signed most significant word multiply subtract - {Rd,} Rn, Rm Signed most significant word multiply - {Rd,} Rn, Rm Signed dual multiply add Q {Rd,} Rn, Rm Signed multiply halfwords - SMULL RdLo, RdHi, Rn, Rm Signed multiply (32x32), 64-bit result - SMULWB, {Rd,} Rn, Rm Signed multiply by halfword - {Rd,} Rn, Rm Signed dual multiply subtract - SSAT Rd, #n, Rm {,shift #s} Signed saturate Q SSAT16 Rd, #n, Rm Signed saturate 16 Q SSAX {Rd,} Rn, Rm Saturating subtract and add with exchange GE SSUB16 {Rd,} Rn, Rm Signed subtract 16 - SSUB8 {Rd,} Rn, Rm Signed subtract 8 - STM Rn{!}, reglist Store multiple registers, increment after - SMLABT, SMLATB, SMLATT SMLAD, SMLADX SMLALBT, SMLALTB, SMLALTT SMLSDX SMLSLD SMLSLDX SMMLR SMMUL, SMMULR SMUAD SMUADX SMULBB, SMULBT, SMULTB, SMULTT SMULWT SMUSD, SMUSDX 130 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 2-13. Cortex-M4F Instruction Summary (continued) Mnemonic Operands Brief Description Flags STMDB, STMEA Rn{!}, reglist Store multiple registers, decrement before - STMFD, STMIA Rn{!}, reglist Store multiple registers, increment after - STR Rt, [Rn {, #offset}] Store register word - STRB, STRBT Rt, [Rn {, #offset}] Store register byte - STRD Rt, Rt2, [Rn {, #offset}] Store register two words - STREX Rt, Rt, [Rn {, #offset}] Store register exclusive - STREXB Rd, Rt, [Rn] Store register exclusive byte - STREXH Rd, Rt, [Rn] Store register exclusive halfword - STRH, STRHT Rt, [Rn {, #offset}] Store register halfword - STRSB, STRSBT Rt, [Rn {, #offset}] Store register signed byte - STRSH, STRSHT Rt, [Rn {, #offset}] Store register signed halfword - STRT Rt, [Rn {, #offset}] Store register word - SUB, SUBS {Rd,} Rn, Op2 Subtract N,Z,C,V SUB, SUBW {Rd,} Rn, #imm12 Subtract 12-bit constant N,Z,C,V SVC #imm Supervisor call - SXTAB {Rd,} Rn, Rm, {,ROR #} Extend 8 bits to 32 and add - SXTAB16 {Rd,} Rn, Rm,{,ROR #} Dual extend 8 bits to 16 and add - SXTAH {Rd,} Rn, Rm,{,ROR #} Extend 16 bits to 32 and add - SXTB16 {Rd,} Rm {,ROR #n} Signed extend byte 16 - SXTB {Rd,} Rm {,ROR #n} Sign extend a byte - SXTH {Rd,} Rm {,ROR #n} Sign extend a halfword - TBB [Rn, Rm] Table branch byte - TBH [Rn, Rm, LSL #1] Table branch halfword - TEQ Rn, Op2 Test equivalence N,Z,C TST Rn, Op2 Test N,Z,C UADD16 {Rd,} Rn, Rm Unsigned add 16 GE UADD8 {Rd,} Rn, Rm Unsigned add 8 GE UASX {Rd,} Rn, Rm Unsigned add and subtract with exchange GE UHADD16 {Rd,} Rn, Rm Unsigned halving add 16 - UHADD8 {Rd,} Rn, Rm Unsigned halving add 8 - UHASX {Rd,} Rn, Rm Unsigned halving add and subtract with exchange UHSAX {Rd,} Rn, Rm Unsigned halving subtract and add with exchange UHSUB16 {Rd,} Rn, Rm Unsigned halving subtract 16 - UHSUB8 {Rd,} Rn, Rm Unsigned halving subtract 8 - UBFX Rd, Rn, #lsb, #width Unsigned bit field extract - UDIV {Rd,} Rn, Rm Unsigned divide - UMAAL RdLo, RdHi, Rn, Rm Unsigned multiply accumulate accumulate long (32x32+64), 64-bit result - June 18, 2014 131 Texas Instruments-Production Data The Cortex-M4F Processor Table 2-13. Cortex-M4F Instruction Summary (continued) Mnemonic Operands Brief Description Flags UMLAL RdLo, RdHi, Rn, Rm Unsigned multiply with accumulate (32x32+32+32), 64-bit result - UMULL RdLo, RdHi, Rn, Rm Unsigned multiply (32x 2), 64-bit result - UQADD16 {Rd,} Rn, Rm Unsigned Saturating Add 16 - UQADD8 {Rd,} Rn, Rm Unsigned Saturating Add 8 - UQASX {Rd,} Rn, Rm Unsigned Saturating Add and Subtract with Exchange UQSAX {Rd,} Rn, Rm Unsigned Saturating Subtract and Add with Exchange UQSUB16 {Rd,} Rn, Rm Unsigned Saturating Subtract 16 - UQSUB8 {Rd,} Rn, Rm Unsigned Saturating Subtract 8 - USAD8 {Rd,} Rn, Rm Unsigned Sum of Absolute Differences - USADA8 {Rd,} Rn, Rm, Ra Unsigned Sum of Absolute Differences and Accumulate USAT Rd, #n, Rm {,shift #s} Unsigned Saturate Q USAT16 Rd, #n, Rm Unsigned Saturate 16 Q USAX {Rd,} Rn, Rm Unsigned Subtract and add with Exchange GE USUB16 {Rd,} Rn, Rm Unsigned Subtract 16 GE USUB8 {Rd,} Rn, Rm Unsigned Subtract 8 GE UXTAB {Rd,} Rn, Rm, {,ROR #} Rotate, extend 8 bits to 32 and Add - UXTAB16 {Rd,} Rn, Rm, {,ROR #} Rotate, dual extend 8 bits to 16 and Add - UXTAH {Rd,} Rn, Rm, {,ROR #} Rotate, unsigned extend and Add Halfword - UXTB {Rd,} Rm, {,ROR #n} Zero extend a Byte - UXTB16 {Rd,} Rm, {,ROR #n} Unsigned Extend Byte 16 - UXTH {Rd,} Rm, {,ROR #n} Zero extend a Halfword - VABS.F32 Sd, Sm Floating-point Absolute - VADD.F32 {Sd,} Sn, Sm Floating-point Add - VCMP.F32 Sd, Compare two floating-point registers, or FPSCR one floating-point register and zero VCMPE.F32 Sd, Compare two floating-point registers, or FPSCR one floating-point register and zero with Invalid Operation check VCVT.S32.F32 Sd, Sm Convert between floating-point and integer VCVT.S16.F32 Sd, Sd, #fbits Convert between floating-point and fixed point VCVTR.S32.F32 Sd, Sm Convert between floating-point and integer with rounding - VCVT.F32.F16 Sd, Sm Converts half-precision value to single-precision - VCVTT.F32.F16 Sd, Sm Converts single-precision register to half-precision - VDIV.F32 {Sd,} Sn, Sm Floating-point Divide - VFMA.F32 {Sd,} Sn, Sm Floating-point Fused Multiply Accumulate - 132 - June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 2-13. Cortex-M4F Instruction Summary (continued) Mnemonic Operands Brief Description Flags VFNMA.F32 {Sd,} Sn, Sm Floating-point Fused Negate Multiply Accumulate - VFMS.F32 {Sd,} Sn, Sm Floating-point Fused Multiply Subtract - VFNMS.F32 {Sd,} Sn, Sm Floating-point Fused Negate Multiply Subtract - VLDM.F Rn{!}, list Load Multiple extension registers - VLDR.F , [Rn] Load an extension register from memory - VLMA.F32 {Sd,} Sn, Sm Floating-point Multiply Accumulate - VLMS.F32 {Sd,} Sn, Sm Floating-point Multiply Subtract - VMOV.F32 Sd, #imm Floating-point Move immediate - VMOV Sd, Sm Floating-point Move register - VMOV Sn, Rt Copy ARM core register to single precision - VMOV Sm, Sm1, Rt, Rt2 Copy 2 ARM core registers to 2 single precision - VMOV Dd[x], Rt Copy ARM core register to scalar - VMOV Rt, Dn[x] Copy scalar to ARM core register - VMRS Rt, FPSCR Move FPSCR to ARM core register or APSR N,Z,C,V VMSR FPSCR, Rt Move to FPSCR from ARM Core register FPSCR VMUL.F32 {Sd,} Sn, Sm Floating-point Multiply - VNEG.F32 Sd, Sm Floating-point Negate - VNMLA.F32 {Sd,} Sn, Sm Floating-point Multiply and Add - VNMLS.F32 {Sd,} Sn, Sm Floating-point Multiply and Subtract - VNMUL {Sd,} Sn, Sm Floating-point Multiply - VPOP list Pop extension registers - VPUSH list Push extension registers - VSQRT.F32 Sd, Sm Calculates floating-point Square Root - VSTM Rn{!}, list Floating-point register Store Multiple - VSTR.F3 Sd, [Rn] Stores an extension register to memory - VSUB.F {Sd,} Sn, Sm Floating-point Subtract - WFE - Wait for event - WFI - Wait for interrupt - June 18, 2014 133 Texas Instruments-Production Data Cortex-M4 Peripherals 3 Cortex-M4 Peripherals This chapter provides information on the Tiva™ C Series implementation of the Cortex-M4 processor peripherals, including: ■ SysTick (see page 135) Provides a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. ■ Nested Vectored Interrupt Controller (NVIC) (see page 136) – Facilitates low-latency exception and interrupt handling – Controls power management – Implements system control registers ■ System Control Block (SCB) (see page 137) Provides system implementation information and system control, including configuration, control, and reporting of system exceptions. ■ Memory Protection Unit (MPU) (see page 137) Supports the standard ARMv7 Protected Memory System Architecture (PMSA) model. The MPU provides full support for protection regions, overlapping protection regions, access permissions, and exporting memory attributes to the system. ■ Floating-Point Unit (FPU) (see page 142) Fully supports single-precision add, subtract, multiply, divide, multiply and accumulate, and square root operations. It also provides conversions between fixed-point and floating-point data formats, and floating-point constant instructions. Table 3-1 on page 134 shows the address map of the Private Peripheral Bus (PPB). Some peripheral register regions are split into two address regions, as indicated by two addresses listed. Table 3-1. Core Peripheral Register Regions Address Core Peripheral Description (see page ...) 0xE000.E010-0xE000.E01F System Timer 135 0xE000.E100-0xE000.E4EF Nested Vectored Interrupt Controller 136 System Control Block 137 0xE000.ED90-0xE000.EDB8 Memory Protection Unit 137 0xE000.EF30-0xE000.EF44 Floating Point Unit 142 0xE000.EF00-0xE000.EF03 0xE000.E008-0xE000.E00F 0xE000.ED00-0xE000.ED3F 3.1 Functional Description This chapter provides information on the Tiva™ C Series implementation of the Cortex-M4 processor peripherals: SysTick, NVIC, SCB, MPU, FPU. 134 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 3.1.1 System Timer (SysTick) Cortex-M4 includes an integrated system timer, SysTick, which provides a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. The counter can be used in several different ways, for example as: ■ An RTOS tick timer that fires at a programmable rate (for example, 100 Hz) and invokes a SysTick routine. ■ A high-speed alarm timer using the system clock. ■ A variable rate alarm or signal timer—the duration is range-dependent on the reference clock used and the dynamic range of the counter. ■ A simple counter used to measure time to completion and time used. ■ An internal clock source control based on missing/meeting durations. The COUNT bit in the STCTRL control and status register can be used to determine if an action completed within a set duration, as part of a dynamic clock management control loop. The timer consists of three registers: ■ SysTick Control and Status (STCTRL): A control and status counter to configure its clock, enable the counter, enable the SysTick interrupt, and determine counter status. ■ SysTick Reload Value (STRELOAD): The reload value for the counter, used to provide the counter's wrap value. ■ SysTick Current Value (STCURRENT): The current value of the counter. When enabled, the timer counts down on each clock from the reload value to zero, reloads (wraps) to the value in the STRELOAD register on the next clock edge, then decrements on subsequent clocks. Clearing the STRELOAD register disables the counter on the next wrap. When the counter reaches zero, the COUNT status bit is set. The COUNT bit clears on reads. Writing to the STCURRENT register clears the register and the COUNT status bit. The write does not trigger the SysTick exception logic. On a read, the current value is the value of the register at the time the register is accessed. The SysTick counter runs on the system clock. If this clock signal is stopped for low power mode, the SysTick counter stops. Ensure software uses aligned word accesses to access the SysTick registers. The SysTick counter reload and current value are undefined at reset; the correct initialization sequence for the SysTick counter is: 1. Program the value in the STRELOAD register. 2. Clear the STCURRENT register by writing to it with any value. 3. Configure the STCTRL register for the required operation. Note: When the processor is halted for debugging, the counter does not decrement. June 18, 2014 135 Texas Instruments-Production Data Cortex-M4 Peripherals 3.1.2 Nested Vectored Interrupt Controller (NVIC) This section describes the Nested Vectored Interrupt Controller (NVIC) and the registers it uses. The NVIC supports: ■ 106 interrupts. ■ A programmable priority level of 0-7 for each interrupt. A higher level corresponds to a lower priority, so level 0 is the highest interrupt priority. ■ Low-latency exception and interrupt handling. ■ Level and pulse detection of interrupt signals. ■ Dynamic reprioritization of interrupts. ■ Grouping of priority values into group priority and subpriority fields. ■ Interrupt tail-chaining. ■ An external Non-maskable interrupt (NMI). The processor automatically stacks its state on exception entry and unstacks this state on exception exit, with no instruction overhead, providing low latency exception handling. 3.1.2.1 Level-Sensitive and Pulse Interrupts The processor supports both level-sensitive and pulse interrupts. Pulse interrupts are also described as edge-triggered interrupts. A level-sensitive interrupt is held asserted until the peripheral deasserts the interrupt signal. Typically this happens because the ISR accesses the peripheral, causing it to clear the interrupt request. A pulse interrupt is an interrupt signal sampled synchronously on the rising edge of the processor clock. To ensure the NVIC detects the interrupt, the peripheral must assert the interrupt signal for at least one clock cycle, during which the NVIC detects the pulse and latches the interrupt. When the processor enters the ISR, it automatically removes the pending state from the interrupt (see “Hardware and Software Control of Interrupts” on page 136 for more information). For a level-sensitive interrupt, if the signal is not deasserted before the processor returns from the ISR, the interrupt becomes pending again, and the processor must execute its ISR again. As a result, the peripheral can hold the interrupt signal asserted until it no longer needs servicing. 3.1.2.2 Hardware and Software Control of Interrupts The Cortex-M4 latches all interrupts. A peripheral interrupt becomes pending for one of the following reasons: ■ The NVIC detects that the interrupt signal is High and the interrupt is not active. ■ The NVIC detects a rising edge on the interrupt signal. ■ Software writes to the corresponding interrupt set-pending register bit, or to the Software Trigger Interrupt (SWTRIG) register to make a Software-Generated Interrupt pending. See the INT bit in the PEND0 register on page 156 or SWTRIG on page 163. A pending interrupt remains pending until one of the following: 136 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ The processor enters the ISR for the interrupt, changing the state of the interrupt from pending to active. Then: – For a level-sensitive interrupt, when the processor returns from the ISR, the NVIC samples the interrupt signal. If the signal is asserted, the state of the interrupt changes to pending, which might cause the processor to immediately re-enter the ISR. Otherwise, the state of the interrupt changes to inactive. – For a pulse interrupt, the NVIC continues to monitor the interrupt signal, and if this is pulsed the state of the interrupt changes to pending and active. In this case, when the processor returns from the ISR the state of the interrupt changes to pending, which might cause the processor to immediately re-enter the ISR. If the interrupt signal is not pulsed while the processor is in the ISR, when the processor returns from the ISR the state of the interrupt changes to inactive. ■ Software writes to the corresponding interrupt clear-pending register bit – For a level-sensitive interrupt, if the interrupt signal is still asserted, the state of the interrupt does not change. Otherwise, the state of the interrupt changes to inactive. – For a pulse interrupt, the state of the interrupt changes to inactive, if the state was pending or to active, if the state was active and pending. 3.1.3 System Control Block (SCB) The System Control Block (SCB) provides system implementation information and system control, including configuration, control, and reporting of the system exceptions. 3.1.4 Memory Protection Unit (MPU) This section describes the Memory protection unit (MPU). The MPU divides the memory map into a number of regions and defines the location, size, access permissions, and memory attributes of each region. The MPU supports independent attribute settings for each region, overlapping regions, and export of memory attributes to the system. The memory attributes affect the behavior of memory accesses to the region. The Cortex-M4 MPU defines eight separate memory regions, 0-7, and a background region. When memory regions overlap, a memory access is affected by the attributes of the region with the highest number. For example, the attributes for region 7 take precedence over the attributes of any region that overlaps region 7. The background region has the same memory access attributes as the default memory map, but is accessible from privileged software only. The Cortex-M4 MPU memory map is unified, meaning that instruction accesses and data accesses have the same region settings. If a program accesses a memory location that is prohibited by the MPU, the processor generates a memory management fault, causing a fault exception and possibly causing termination of the process in an OS environment. In an OS environment, the kernel can update the MPU region setting dynamically based on the process to be executed. Typically, an embedded OS uses the MPU for memory protection. Configuration of MPU regions is based on memory types (see “Memory Regions, Types and Attributes” on page 106 for more information). June 18, 2014 137 Texas Instruments-Production Data Cortex-M4 Peripherals Table 3-2 on page 138 shows the possible MPU region attributes. See the section called “MPU Configuration for a Tiva™ C Series Microcontroller” on page 142 for guidelines for programming a microcontroller implementation. Table 3-2. Memory Attributes Summary Memory Type Description Strongly Ordered All accesses to Strongly Ordered memory occur in program order. Device Memory-mapped peripherals Normal Normal memory To avoid unexpected behavior, disable the interrupts before updating the attributes of a region that the interrupt handlers might access. Ensure software uses aligned accesses of the correct size to access MPU registers: ■ Except for the MPU Region Attribute and Size (MPUATTR) register, all MPU registers must be accessed with aligned word accesses. ■ The MPUATTR register can be accessed with byte or aligned halfword or word accesses. The processor does not support unaligned accesses to MPU registers. When setting up the MPU, and if the MPU has previously been programmed, disable unused regions to prevent any previous region settings from affecting the new MPU setup. 3.1.4.1 Updating an MPU Region To update the attributes for an MPU region, the MPU Region Number (MPUNUMBER), MPU Region Base Address (MPUBASE) and MPUATTR registers must be updated. Each register can be programmed separately or with a multiple-word write to program all of these registers. You can use the MPUBASEx and MPUATTRx aliases to program up to four regions simultaneously using an STM instruction. Updating an MPU Region Using Separate Words This example simple code configures one region: ; R1 = region number ; R2 = size/enable ; R3 = attributes ; R4 = address LDR R0,=MPUNUMBER STR R1, [R0, #0x0] STR R4, [R0, #0x4] STRH R2, [R0, #0x8] STRH R3, [R0, #0xA] ; ; ; ; ; 0xE000ED98, MPU region number register Region Number Region Base Address Region Size and Enable Region Attribute Disable a region before writing new region settings to the MPU if you have previously enabled the region being changed. For example: ; R1 = region number ; R2 = size/enable ; R3 = attributes ; R4 = address LDR R0,=MPUNUMBER ; 0xE000ED98, MPU region number register 138 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller STR R1, [R0, #0x0] BIC R2, R2, #1 STRH R2, [R0, #0x8] STR R4, [R0, #0x4] STRH R3, [R0, #0xA] ORR R2, #1 STRH R2, [R0, #0x8] ; ; ; ; ; ; ; Region Number Disable Region Size and Enable Region Base Address Region Attribute Enable Region Size and Enable Software must use memory barrier instructions: ■ Before MPU setup, if there might be outstanding memory transfers, such as buffered writes, that might be affected by the change in MPU settings. ■ After MPU setup, if it includes memory transfers that must use the new MPU settings. However, memory barrier instructions are not required if the MPU setup process starts by entering an exception handler, or is followed by an exception return, because the exception entry and exception return mechanism cause memory barrier behavior. Software does not need any memory barrier instructions during MPU setup, because it accesses the MPU through the Private Peripheral Bus (PPB), which is a Strongly Ordered memory region. For example, if all of the memory access behavior is intended to take effect immediately after the programming sequence, then a DSB instruction and an ISB instruction should be used. A DSB is required after changing MPU settings, such as at the end of context switch. An ISB is required if the code that programs the MPU region or regions is entered using a branch or call. If the programming sequence is entered using a return from exception, or by taking an exception, then an ISB is not required. Updating an MPU Region Using Multi-Word Writes The MPU can be programmed directly using multi-word writes, depending how the information is divided. Consider the following reprogramming: ; R1 = region number ; R2 = address ; R3 = size, attributes in one LDR R0, =MPUNUMBER ; 0xE000ED98, MPU region number register STR R1, [R0, #0x0] ; Region Number STR R2, [R0, #0x4] ; Region Base Address STR R3, [R0, #0x8] ; Region Attribute, Size and Enable An STM instruction can be used to optimize this: ; R1 = region number ; R2 = address ; R3 = size, attributes in one LDR R0, =MPUNUMBER ; 0xE000ED98, MPU region number register STM R0, {R1-R3} ; Region number, address, attribute, size and enable This operation can be done in two words for prepacked information, meaning that the MPU Region Base Address (MPUBASE) register (see page 197) contains the required region number and has the VALID bit set. This method can be used when the data is statically packed, for example in a boot loader: June 18, 2014 139 Texas Instruments-Production Data Cortex-M4 Peripherals ; R1 = address and region number in one ; R2 = size and attributes in one LDR R0, =MPUBASE ; 0xE000ED9C, MPU Region Base register STR R1, [R0, #0x0] ; Region base address and region number combined ; with VALID (bit 4) set STR R2, [R0, #0x4] ; Region Attribute, Size and Enable Subregions Regions of 256 bytes or more are divided into eight equal-sized subregions. Set the corresponding bit in the SRD field of the MPU Region Attribute and Size (MPUATTR) register (see page 199) to disable a subregion. The least-significant bit of the SRD field controls the first subregion, and the most-significant bit controls the last subregion. Disabling a subregion means another region overlapping the disabled range matches instead. If no other enabled region overlaps the disabled subregion, the MPU issues a fault. Regions of 32, 64, and 128 bytes do not support subregions. With regions of these sizes, the SRD field must be configured to 0x00, otherwise the MPU behavior is unpredictable. Example of SRD Use Two regions with the same base address overlap. Region one is 128 KB, and region two is 512 KB. To ensure the attributes from region one apply to the first 128 KB region, configure the SRD field for region two to 0x03 to disable the first two subregions, as Figure 3-1 on page 140 shows. Figure 3-1. SRD Use Example Region 2, with subregions Region 1 Base address of both regions 3.1.4.2 Offset from base address 512KB 448KB 384KB 320KB 256KB 192KB 128KB Disabled subregion 64KB Disabled subregion 0 MPU Access Permission Attributes The access permission bits, TEX, S, C, B, AP, and XN of the MPUATTR register, control access to the corresponding memory region. If an access is made to an area of memory without the required permissions, then the MPU generates a permission fault. Table 3-3 on page 140 shows the encodings for the TEX, C, B, and S access permission bits. All encodings are shown for completeness, however the current implementation of the Cortex-M4 does not support the concept of cacheability or shareability. Refer to the section called “MPU Configuration for a Tiva™ C Series Microcontroller” on page 142 for information on programming the MPU for TM4C1294NCPDT implementations. Table 3-3. TEX, S, C, and B Bit Field Encoding TEX S 000b x 000 B Memory Type Shareability Other Attributes 0 0 Strongly Ordered Shareable - a 0 1 Device Shareable - x C a 140 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 3-3. TEX, S, C, and B Bit Field Encoding (continued) TEX S C B Memory Type Shareability 000 0 1 0 Normal Not shareable 000 1 1 0 Normal Shareable 000 0 1 1 Normal Not shareable 000 1 1 1 Normal Shareable Other Attributes Outer and inner write-through. No write allocate. 001 0 0 0 Normal Not shareable 001 1 0 0 Normal Shareable Outer and inner non-cacheable. 001 x a 0 1 Reserved encoding - - a 001 x 1 0 Reserved encoding - - 001 0 1 1 Normal Not shareable 001 1 1 1 Normal Shareable Outer and inner write-back. Write and read allocate. 010 x a 0 0 Device Not shareable Nonshared Device. a a 010 x 0 1 Reserved encoding - - 010 x 1 x Reserved encoding - - 1BB 0 A A Normal Not shareable 1BB 1 A A Normal Shareable Cached memory (BB = outer policy, AA = inner policy). a See Table 3-4 for the encoding of the AA and BB bits. a. The MPU ignores the value of this bit. Table 3-4 on page 141 shows the cache policy for memory attribute encodings with a TEX value in the range of 0x4-0x7. Table 3-4. Cache Policy for Memory Attribute Encoding Encoding, AA or BB Corresponding Cache Policy 00 Non-cacheable 01 Write back, write and read allocate 10 Write through, no write allocate 11 Write back, no write allocate Table 3-5 on page 141 shows the AP encodings in the MPUATTR register that define the access permissions for privileged and unprivileged software. Table 3-5. AP Bit Field Encoding AP Bit Field Privileged Permissions Unprivileged Permissions Description 000 No access No access All accesses generate a permission fault. 001 RW No access Access from privileged software only. 010 RW RO Writes by unprivileged software generate a permission fault. 011 RW RW Full access. 100 Unpredictable Unpredictable Reserved. 101 RO No access Reads by privileged software only. June 18, 2014 141 Texas Instruments-Production Data Cortex-M4 Peripherals Table 3-5. AP Bit Field Encoding (continued) AP Bit Field Privileged Permissions Unprivileged Permissions Description 110 RO RO Read-only, by privileged or unprivileged software. 111 RO RO Read-only, by privileged or unprivileged software. MPU Configuration for a Tiva™ C Series Microcontroller Tiva™ C Series microcontrollers have only a single processor and no caches. As a result, the MPU should be programmed as shown in Table 3-6 on page 142. Table 3-6. Memory Region Attributes for Tiva™ C Series Microcontrollers Memory Region TEX S C B Memory Type and Attributes Flash memory 000b 0 1 0 Normal memory, non-shareable, write-through Internal SRAM 000b 1 1 0 Normal memory, shareable, write-through External SRAM 000b 1 1 1 Normal memory, shareable, write-back, write-allocate Peripherals 000b 1 0 1 Device memory, shareable In current Tiva™ C Series microcontroller implementations, the shareability and cache policy attributes do not affect the system behavior. However, using these settings for the MPU regions can make the application code more portable. The values given are for typical situations. 3.1.4.3 MPU Mismatch When an access violates the MPU permissions, the processor generates a memory management fault (see “Exceptions and Interrupts” on page 103 for more information). The MFAULTSTAT register indicates the cause of the fault. See page 184 for more information. 3.1.5 Floating-Point Unit (FPU) This section describes the Floating-Point Unit (FPU) and the registers it uses. The FPU provides: ■ 32-bit instructions for single-precision (C float) data-processing operations ■ Combined multiply and accumulate instructions for increased precision (Fused MAC) ■ Hardware support for conversion, addition, subtraction, multiplication with optional accumulate, division, and square-root ■ Hardware support for denormals and all IEEE rounding modes ■ 32 dedicated 32-bit single-precision registers, also addressable as 16 double-word registers ■ Decoupled three stage pipeline The Cortex-M4F FPU fully supports single-precision add, subtract, multiply, divide, multiply and accumulate, and square root operations. It also provides conversions between fixed-point and floating-point data formats, and floating-point constant instructions. The FPU provides floating-point computation functionality that is compliant with the ANSI/IEEE Std 754-2008, IEEE Standard for Binary Floating-Point Arithmetic, referred to as the IEEE 754 standard. The FPU's single-precision extension registers can also be accessed as 16 doubleword registers for load, store, and move operations. 142 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 3.1.5.1 FPU Views of the Register Bank The FPU provides an extension register file containing 32 single-precision registers. These can be viewed as: ■ Sixteen 64-bit doubleword registers, D0-D15 ■ Thirty-two 32-bit single-word registers, S0-S31 ■ A combination of registers from the above views Figure 3-2. FPU Register Bank S0 S1 S2 S3 S4 S5 S6 S7 ... S28 S29 S30 S31 D0 D1 D2 D3 ... D14 D15 The mapping between the registers is as follows: ■ S maps to the least significant half of D ■ S maps to the most significant half of D For example, you can access the least significant half of the value in D6 by accessing S12, and the most significant half of the elements by accessing S13. 3.1.5.2 Modes of Operation The FPU provides three modes of operation to accommodate a variety of applications. Full-Compliance mode. In Full-Compliance mode, the FPU processes all operations according to the IEEE 754 standard in hardware. Flush-to-Zero mode. Setting the FZ bit of the Floating-Point Status and Control (FPSC) register enables Flush-to-Zero mode. In this mode, the FPU treats all subnormal input operands of arithmetic CDP operations as zeros in the operation. Exceptions that result from a zero operand are signalled appropriately. VABS, VNEG, and VMOV are not considered arithmetic CDP operations and are not affected by Flush-to-Zero mode. A result that is tiny, as described in the IEEE 754 standard, where the destination precision is smaller in magnitude than the minimum normal value before rounding, is replaced with a zero. The IDC bit in FPSC indicates when an input flush occurs. The UFC bit in FPSC indicates when a result flush occurs. Default NaN mode. Setting the DN bit in the FPSC register enables default NaN mode. In this mode, the result of any arithmetic data processing operation that involves an input NaN, or that generates a NaN result, returns the default NaN. Propagation of the fraction bits is maintained only by VABS, June 18, 2014 143 Texas Instruments-Production Data Cortex-M4 Peripherals VNEG, and VMOV operations. All other CDP operations ignore any information in the fraction bits of an input NaN. 3.1.5.3 Compliance with the IEEE 754 standard When Default NaN (DN) and Flush-to-Zero (FZ) modes are disabled, FPv4 functionality is compliant with the IEEE 754 standard in hardware. No support code is required to achieve this compliance. 3.1.5.4 Complete Implementation of the IEEE 754 standard The Cortex-M4F floating point instruction set does not support all operations defined in the IEEE 754-2008 standard. Unsupported operations include, but are not limited to the following: ■ Remainder ■ Round floating-point number to integer-valued floating-point number ■ Binary-to-decimal conversions ■ Decimal-to-binary conversions ■ Direct comparison of single-precision and double-precision values The Cortex-M4 FPU supports fused MAC operations as described in the IEEE standard. For complete implementation of the IEEE 754-2008 standard, floating-point functionality must be augmented with library functions. 3.1.5.5 IEEE 754 standard implementation choices NaN handling All single-precision values with the maximum exponent field value and a nonzero fraction field are valid NaNs. A most-significant fraction bit of zero indicates a Signaling NaN (SNaN). A one indicates a Quiet NaN (QNaN). Two NaN values are treated as different NaNs if they differ in any bit. The below table shows the default NaN values. Sign Fraction Fraction 0 0xFF bit [22] = 1, bits [21:0] are all zeros Processing of input NaNs for ARM floating-point functionality and libraries is defined as follows: ■ In full-compliance mode, NaNs are handled as described in the ARM Architecture Reference Manual. The hardware processes the NaNs directly for arithmetic CDP instructions. For data transfer operations, NaNs are transferred without raising the Invalid Operation exception. For the non-arithmetic CDP instructions, VABS, VNEG, and VMOV, NaNs are copied, with a change of sign if specified in the instructions, without causing the Invalid Operation exception. ■ In default NaN mode, arithmetic CDP instructions involving NaN operands return the default NaN regardless of the fractions of any NaN operands. SNaNs in an arithmetic CDP operation set the IOC flag, FPSCR[0]. NaN handling by data transfer and non-arithmetic CDP instructions is the same as in full-compliance mode. 144 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 3-7. QNaN and SNaN Handling Instruction Type Default NaN Mode With QNaN Operand With SNaN Operand Off The QNaN or one of the QNaN operands, if there is more than one, is returned according to the rules given in the ARM Architecture Reference Manual. IOC set. The SNaN is quieted and the result NaN is determined by the rules given in the ARM Architecture Reference Manual. On Default NaN returns. IOC set. Default NaN returns. Arithmetic CDP Non-arithmetic CDP Off/On a a NaN passes to destination with sign changed as appropriate. FCMP(Z) - Unordered compare. IOC set. Unordered compare. FCMPE(Z) - IOC set. Unordered compare. IOC set. Unordered compare. Load/store Off/On All NaNs transferred. a. IOC is the Invalid Operation exception flag, FPSCR[0]. Comparisons Comparison results modify the flags in the FPSCR. You can use the MVRS APSR_nzcv instruction (formerly FMSTAT) to transfer the current flags from the FPSCR to the APSR. See the ARM Architecture Reference Manual for mapping of IEEE 754-2008 standard predicates to ARM conditions. The flags used are chosen so that subsequent conditional execution of ARM instructions can test the predicates defined in the IEEE standard. Underflow The Cortex-M4F FPU uses the before rounding form of tininess and the inexact result form of loss of accuracy as described in the IEEE 754-2008 standard to generate Underflow exceptions. In flush-to-zero mode, results that are tiny before rounding, as described in the IEEE standard, are flushed to a zero, and the UFC flag, FPSCR[3], is set. See the ARM Architecture Reference Manual for information on flush-to-zero mode. When the FPU is not in flush-to-zero mode, operations are performed on subnormal operands. If the operation does not produce a tiny result, it returns the computed result, and the UFC flag, FPSCR[3], is not set. The IXC flag, FPSCR[4], is set if the operation is inexact. If the operation produces a tiny result, the result is a subnormal or zero value, and the UFC flag, FPSCR[3], is set if the result was also inexact. 3.1.5.6 Exceptions The FPU sets the cumulative exception status flag in the FPSCR register as required for each instruction, in accordance with the FPv4 architecture. The FPU does not support user-mode traps. The exception enable bits in the FPSCR read-as-zero, and writes are ignored. The processor also has six output pins, FPIXC, FPUFC, FPOFC, FPDZC, FPIDC, and FPIOC, that each reflect the status of one of the cumulative exception flags. For a description of these outputs, see the ARM Cortex-M4 Integration and Implementation Manual (ARM DII 0239, available from ARM). The processor can reduce the exception latency by using lazy stacking. See Auxiliary Control Register, ACTLR on page 4-5. This means that the processor reserves space on the stack for the FP state, but does not save that state information to the stack. See the ARMv7-M Architecture Reference Manual (available from ARM) for more information. 3.1.5.7 Enabling the FPU The FPU is disabled from reset. You must enable it before you can use any floating-point instructions. The processor must be in privileged mode to read from and write to the Coprocessor Access June 18, 2014 145 Texas Instruments-Production Data Cortex-M4 Peripherals Control (CPAC) register. The below example code sequence enables the FPU in both privileged and user modes. ; CPACR is located at address 0xE000ED88 LDR.W R0, =0xE000ED88 ; Read CPACR LDR R1, [R0] ; Set bits 20-23 to enable CP10 and CP11 coprocessors ORR R1, R1, #(0xF VDD ■ Dedicated pin for waking using an external signal ■ Capability to configure external reset (RST) pin and/or up to four GPIO port pins as wake source, with programmable wake level ■ Tamper Functionality – Support for four tamper inputs – Configurable level, weak pull-up, and glitch filter – Configurable tamper event response – Logging of up to four tamper events – Optional BBRAM erase on tamper detection – Tamper wake from hibernate capability June 18, 2014 531 Texas Instruments-Production Data Hibernation Module – Hibernation clock input failure detect with a switch to the internal oscillator on detection ■ RTC operational and hibernation memory valid as long as VDD or VBAT is valid ■ Low-battery detection, signaling, and interrupt generation, with optional wake on low battery ■ GPIO pin state can be retained during hibernation ■ Clock source from an internal low frequency oscillator (HIB LFIOSC) or a 32.768-kHz external crystal or oscillator ■ Sixteen 32-bit words of battery-backed memory to save state during hibernation ■ Programmable interrupts for: – RTC match – External wake – Low battery 532 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 7.1 Block Diagram Figure 7-1. Hibernation Module Block Diagram Alternate Clock for LPC Clock Source for System Clock To GPIO Module HIBCTL.CLK32EN & HIBCTL.OSCSEL HIBCC. ALTCLK1EN Low Frequency Oscillator XOSC0 32.786 kHz Oscillator I/O Config. HIBCC. SYSCLKEN HIBIO Interrupts HIBIM HIBRIS HIBMIS HIBIC Pre-Divider XOSC1 HIBRTCT HIBCTL.CLK32EN & HIBCTL.OSCSEL RTC HIBRTCC HIBRTCLD HIBRTCM0 HIBRTCSS Battery-Backed Memory 16 words HIBDATA Interrupts to CPU MATCH RTCCLK HIBCTL.RTCEN WAKE LOWBAT Low Battery Detect VBAT HIBCTL.VBATSEL HIBCTL.BATCHK Power Sequence Logic HIB HIBCTL.RTCWEN HIBCTL.PINWEN HIBCTL.VABORT HIBCTL.HIBREQ HIBCTL.BATWKEN Note: 7.2 References to alternate clock to LPC only apply to devices which have LPC. Signal Description The following table lists the external signals of the Hibernation module and describes the function of each. The RTCCLK and TMPR[3:0] signals are alternate functions for a GPIO signal and defaults to be a GPIO signal at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the GPIO pin placement for the RTCCLK and TMPR[3:0] signals. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign each signal to its specified GPIO port pin. In addition, the AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the proper HIB function. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. The remaining signals have a fixed pin assignment and function. June 18, 2014 533 Texas Instruments-Production Data Hibernation Module Note: In addition to the Hibernation signals that are part of the Hibernation Module, GPIO pins K[7:4] can be configured as external wake sources. Refer to “Waking from Hibernate” on page 546 for more information. Note: Port pins PM[7:4] operate as Fast GPIO pads but support only 2-, 4-, 6-, and 8-mA drive capability. 10- and 12-mA drive are not supported. All standard GPIO register controls, except for the GPIODR12R register, apply to these port pins. Refer to “General-Purpose Input/Outputs (GPIOs)” on page 742 and “Recommended GPIO Operating Characteristics” on page 1820 for more information. Table 7-1. Hibernate Signals (128TQFP) Pin Name 7.3 Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description HIB 65 fixed O TTL An output that indicates the processor is in Hibernate mode. RTCCLK 24 60 104 PC5 (7) PK7 (5) PP3 (7) O TTL Buffered version of the Hibernation module's 32.768-kHz clock. This signal is not output when the part is in Hibernate mode and before being configured after power-on reset. TMPR0 71 PM7 I/O TTL Tamper signal 0. TMPR1 72 PM6 I/O TTL Tamper signal 1. TMPR2 73 PM5 I/O TTL Tamper signal 2. TMPR3 74 PM4 I/O TTL Tamper signal 3. VBAT 68 fixed - Power Power source for the Hibernation module. It is normally connected to the positive terminal of a battery and serves as the battery backup/Hibernation module power-source supply. WAKE 64 fixed I TTL An external input that brings the processor out of Hibernate mode when asserted. XOSC0 66 fixed I Analog Hibernation module oscillator crystal input or an external clock reference input. Note that this is either a crystal or a 32.768-kHz oscillator for the Hibernation module RTC. XOSC1 67 fixed O Analog Hibernation module oscillator crystal output. Leave unconnected when using a single-ended clock source. Functional Description The Hibernation module provides two mechanisms for power control: ■ The first mechanism uses internal switches to control power to the Cortex-M4F as well as to most analog and digital functions while retaining I/O pin power (VDD3ON mode). ■ The second mechanism controls the power to the microcontroller with a control signal (HIB) that signals an external voltage regulator to turn on or off. The Hibernation module power source is supplied by VDD as long as it is within a valid range, even if VBAT>VDD. The Hibernation module also has an independent clock source to maintain a real-time clock (RTC) when the system clock is powered down. Hibernate mode can be entered through one of two ways: 534 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ The user initiates hibernation by setting the HIBREQ bit in the Hibernation Control (HIBCTL) register ■ Power is arbitrarily removed from VDD while a valid VBAT is applied Once in hibernation, the module signals an external voltage regulator to turn the power back on when an external pin (WAKE, RST or a wake-enabled GPIO pin) is asserted or when the internal RTC reaches a certain value. The Hibernation module can also detect when the battery voltage is low and optionally prevent hibernation or wake from hibernation when the battery voltage falls below a certain threshold. Note that multiple wake sources can be configured at the same time to generate a wake signal such that any of them can wake the module. When waking from hibernation, the HIB signal is deasserted. The return of VDD causes a POR to be executed. The time from when the WAKE signal is asserted to when code begins execution is equal to the wake-up time (tWAKE_TO_HIB) plus the power-on reset time (TPOR). 7.3.1 Register Access Timing Because the Hibernation module has an independent clocking domain, hibernation registers must be written only with a timing gap between accesses. The delay time is tHIB_REG_ACCESS, therefore software must guarantee that this delay is inserted between back-to-back writes to Hibernation registers or between a write followed by a read. The WC interrupt in the HIBMIS register can be used to notify the application when the Hibernation modules registers can be accessed. Alternatively, software may make use of the WRC bit in the Hibernation Control (HIBCTL) register to ensure that the required timing gap has elapsed. This bit is cleared on a write operation and set once the write completes, indicating to software that another write or read may be started safely. Software should poll HIBCTL for WRC=1 prior to accessing any hibernation register. Back-to-back reads from Hibernation module registers have no timing restrictions. Reads are performed at the full peripheral clock rate. 7.3.2 Hibernation Clock Source The HIB module can be clocked by one of three different clock sources: ■ A 32.768-kHz oscillator ■ An external 32.768-kHz clock source ■ An internal low frequency oscillator (HIB LFIOSC) Table 7-2 on page 535 summarizes the encodings for the bits in the HIBCTL register that are required for each clock source to be enabled. Note that CLK32EN must be set for any Hibernation clock source to be valid. The Hibernation module is not enabled until the CLK32EN bit is set. The HIB clock source is the source of the RTC Oscillator (RTCOSC), which can be selected as the system clock source by programming a 0x4 in the OSCSRC field of the Run and Sleep Mode Configuration (RSCLKCFG) register in the System Control Module. Please refer to “System Control” on page 220 for more information. Table 7-2. HIB Clock Source Configurations HIB Clock Source CLK32EN OSCSEL OSCBYP 32.768 kHz Oscillator 1 0 0 External 32.768-kHz Clock Source 1 0 1 June 18, 2014 535 Texas Instruments-Production Data Hibernation Module Table 7-2. HIB Clock Source Configurations (continued) HIB Clock Source a Low-frequency internal oscillator (HIB LFIOSC) CLK32EN OSCSEL OSCBYP 1 1 0 a. The frequency can have wide variations; refer to “Hibernation Clock Source Specifications” on page 1837 for more details. To use an external crystal, a 32.768-kHz crystal is connected to the XOSC0 and XOSC1 pins. Alternatively, a 32.768-kHz oscillator can be connected to the XOSC0 pin, leaving XOSC1 unconnected. Care must be taken that the voltage amplitude of the 32.768-kHz oscillator is less than VBAT, otherwise, the Hibernation module may draw power from the oscillator and not VBAT during hibernation. See Figure 7-2 on page 537 and Figure 7-3 on page 537. Alternatively, a low frequency oscillator source (HIB LFIOSC) present in the Hibernation module can be a clock source. (The frequency can have wide variations; refer to “Hibernation Clock Source Specifications” on page 1837 for more details.) The intent of this source is to provide an internal low power clock source to enable the use of the asynchronous pin wakes and memory storage without the requirement of an external crystal. To enable the HIB LFIOSC to be the clock source for the Hibernation module, both the OSCSEL bit and the CLK32EN bit in the Hibernation Control (HIBCTL) register must be set. Note: The HIB low-frequency oscillator (HIB LFIOSC) has a wide frequency variation, therefore the RTC is not accurate when using this clock source. It is not recommended to use the HIB LFIOSC as an RTC clock source. The Hibernation module is enabled by setting the CLK32EN bit of the HIBCTL register. The CLK32EN bit must be set before accessing any other Hibernation module register. The type of clock source used for the HIB module is selected by setting the OSCSEL and OSCBYP bit of the HIBCTL register. If the internal low frequency precision oscillator is used as the clock source, the OSCSEL bit should be set to a 1 at the same time the CLK32EN bit is set. If a crystal is used for the clock source, the software must leave a delay of tHIBOSC_START after writing to the CLK32EN bit and before any other accesses to the Hibernation module registers. The delay allows the crystal to power up and stabilize. If an external oscillator is used for the clock source, no delay is needed. When using an external clock source, the OSCBYP bit in the HIBCTL register should be set. When using a crystal clock source, the GNDX pin should be connected to digital ground along with the crystal load capacitors, as shown in Figure 7-2 on page 537. When using an external clock source, the GNDX pin should be connected to digital ground. Note: In the figures below the parameters RBAT and CBAT have recommended values of 51Ω ±5% and 0.1µF ±5%, respectively. See “Hibernation Module” on page 1845 for more information. 536 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 7-2. Using a Crystal as the Hibernation Clock Source with a Single Battery Source Tiva™ Microcontroller Regulator or Switch Input Voltage IN OUT VDD EN XOSC0 X1 XOSC1 C1 C2 GNDX HIB RBAT WAKE Open drain external wake up circuit Note: VBAT 3V Battery CBAT GND RPU Some devices may not supply the GNDX signal. If GNDX is absent, the crystal load capacitors can be tied to GND externally. See “Signal Tables” on page 1772 for pins specific to your device. X1 = Crystal frequency is fXOSC_XTAL. C1,2 = Capacitor value derived from crystal vendor load capacitance specifications. RPU = Pull-up resistor is 200 kΩ RBAT = 51Ω ±5% CBAT = 0.1µF ±20% See “Hibernation Clock Source Specifications” on page 1837 for specific parameter values. Figure 7-3. Using a Dedicated Oscillator as the Hibernation Clock Source with VDD3ON Mode Tiva™ Microcontroller Regulator Input Voltage IN OUT VDD Clock Source XOSC0 (fEXT_OSC) N.C. XOSC1 GNDX HIB RBAT VBAT WAKE Open drain external wake up circuit Note: GND CBAT 3V Battery RPU Some devices may not supply a GNDX signal. See “Signal Tables” on page 1772 for pins specific to your device. RPU = Pull-up resistor is 1 MΩ RBAT = 51Ω ±5% CBAT = 0.1µF ±20% June 18, 2014 537 Texas Instruments-Production Data Hibernation Module 7.3.2.1 Hibernate Clock Output RTCOSC The clock source that is configured as the HIB clock has the option of becoming an internal output, RTCOSC, and being selected as the clock source for the system clock. To enable RTCOSC as a system clock source, the SYSCLKEN bit must be set in the Hibernate Clock Control (HIBCC) register. 7.3.3 System Implementation Several different system configurations are possible when using the Hibernation module: ■ Using a single battery source, where the battery provides both VDD and VBAT, as shown in Figure 7-2 on page 537. ■ Using the VDD3ON mode, where VDD continues to be powered in hibernation, allowing the GPIO pins to retain their states, as shown in Figure 7-3 on page 537. In this mode, VDDC is powered off internally. In VDD3ON mode, the RETCLR bit in the HIBCTL register must be set so that after power is reapplied, GPIO retention is held until software clears the bit. GPIO retention is released when software writes a 0 to the RETCLR bit. ■ Using separate sources for VDD and VBAT. In this mode, additional circuitry is required for system start-up without a battery or with a depleted battery. ■ Using a regulator to provide both VDD and VBAT with a switch enabled by HIB to remove VDD during hibernation as shown in Figure 7-4 on page 538. Figure 7-4. Using a Regulator for Both VDD and VBAT Tiva™ Microcontroller Regulator Input Voltage IN OUT Switch IN OUT VDD EN XOSC0 X1 XOSC1 C1 C2 GNDX HIB WAKE Open drain external wake up circuit Note: VBAT GND RPU Some devices may not supply a GNDX signal. See “Signal Tables” on page 1772 for pins specific to your device. Adding external capacitance to the VBAT supply reduces the accuracy of the low-battery measurement and should be avoided if possible. The diagrams referenced in this section only show the connection to the Hibernation pins and not to the full system. If the application does not require the use of the Hibernation module, refer to “Connections for Unused Signals” on page 1816. In this situation, the HIB bit in the Hibernation Run Mode Clock Gating Control (RCGCHIB) register must be cleared, disabling the system clock to the Hibernation module and Hibernation module registers are not accessible. 538 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 7.3.4 Battery Management Important: System-level factors may affect the accuracy of the low-battery detect circuit. The designer should consider battery type, discharge characteristics, and a test load during battery voltage measurements. The Hibernation module can be independently powered by a battery or an auxiliary power source using the VBAT pin. The module can monitor the voltage level of the battery and detect when the voltage drops below VLOWBAT. The voltage threshold can be between 1.9 V and 2.5 V and is configured using the VBATSEL field in the HIBCTL register. The module can also be configured so that it does not go into Hibernate mode if the battery voltage drops below this threshold. In addition, battery voltage is monitored while in hibernation, and the microcontroller can be configured to wake from hibernation if the battery voltage goes below the threshold using the BATWKEN bit in the HIBCTL register. The Hibernation module is designed to detect a low-battery condition and set the LOWBAT bit of the Hibernation Raw Interrupt Status (HIBRIS) register when this occurs. If the VABORT bit in the HIBCTL register is also set, then the module is prevented from entering Hibernate mode when a low-battery is detected. The module can also be configured to generate an interrupt for the low-battery condition (see “Interrupts and Status” on page 548). 7.3.5 Real-Time Clock The RTC module is designed to keep wall time. The RTC can operate in seconds counter mode or calendar mode. A 32.768 kHz clock source along with a 15-bit predivider reduces the clock to 1 Hz. The 1 Hz clock is used to increment the 32-bit counter and keep track of seconds. In calendar mode, registers are provided which support the tracking of date, month, year and day-of-week. A match register can be configured to interrupt or wake the system from hibernate. In addition, a software trim register is implemented to allow the user to compensate for oscillator inaccuracies using software. 7.3.5.1 RTC Counter - Seconds/Subseconds Mode The clock signal to the RTC is provided by either of the 32.768-kHz clock sources available to the Hibernation module. The Hibernation RTC Counter (HIBRTCC) register displays the seconds value. The Hibernation RTC Sub Seconds register (HIBRTCSS) is provided for additional time resolution of an application requiring less than one-second divisions. The RTC is enabled by setting the RTCEN bit of the HIBCTL register. The RTCEN bit is also used along with the CALEN bit in the Hibernation Calendar Control (HIBCALCTL) register to enable the calender. Thus, if the calendar is enabled, the RTC registers, HIBRTCC, HIBRTCSS, HIBRTCM0 and HIBRTCLD, cannot be used. The RTC counter and sub-seconds counters begin counting immediately once RTCEN is set. Both counters count up. The RTC continues counting as long as the RTC is enabled and a valid VBAT is present, regardless of whether VDD is present or if the device is in hibernation. The HIBRTCC register is set by writing the Hibernation RTC Load (HIBRTCLD) register. A write to the HIBRTCLD register clears the 15-bit sub-seconds counter field, RTCSSC, in the HIBRTCSS register. To ensure a valid read of the RTC value, the HIBRTCC register should be read first, followed by a read of the RTCSSC field in the HIBRTCSS register and then a re-read of the HIBRTCC register. If the two values for the HIBRTCC are equal, the read is valid. By following this procedure, errors in the application caused by the HIBRTCC register rolling over by a count of 1 during a read of the RTCSSC field are prevented. The RTC can be configured to generate an alarm by setting the RTCAL0 bit in the HIBIM register. When an RTC match occurs, an interrupt is generated and displayed in the HIBRIS register. Refer to “RTC Match - Seconds/Subseconds Mode” on page 540 for more information. June 18, 2014 539 Texas Instruments-Production Data Hibernation Module If the RTC is enabled, only a cold POR, where both VBAT and VDD are removed, resets the RTC registers. If any other reset occurs while the RTC is enabled, such as an external RST assertion or BOR reset, the RTC is not reset. The RTC registers can be reset under any type of system reset as long as the RTC, external wake pins and tamper pins are not enabled. A buffered version of the 32.768-kHz signal Hibernate clock source is available on the RTCCLK signal output, which is muxed with a GPIO pin. The RTCCLK signal can be the external 32.786-kHz clock source or the HIB LFIOSC depending on the value of the OSCSEL bit in the HIBCTL register. See “Signal Description” on page 533 or pin mux information and “General-Purpose Input/Outputs (GPIOs)” on page 742 for additional details on initialization and configuration of this signal. The pin does not output RTCCLK when Hibernate mode is active or before the RTCCLK GPIO digital function has been selected through the GPIO Digital Enable (GPIODEN) register in the GPIO module. This includes selecting the RTCCLK signal as an output source in the GPIO Port Control (GPIOPCTL) register and setting the SYSCLKEN bit within the Hibernate Clock Control (HIBCC) register. Note: 7.3.5.2 The HIB low-frequency oscillator (HIB LFIOSC) has a wide frequency variation, therefore the RTC is not accurate when using this clock source. In addition, the RTCCLK signal may not meet the specification shown in Table 27-30 on page 1845. RTC Match - Seconds/Subseconds Mode The Hibernation module includes a 32-bit match register, HIBRTCM0, which is compared to the value of the RTC 32-bit counter, HIBRTCC. The match functionality also extends to the sub-seconds counter. The 15-bit field (RTCSSM) in the HIBRTCSS register is compared to the value of the 15-bit sub-seconds counter. When a match occurs, the RTCALT0 bit is set in the HIBRIS register. For applications using Hibernate mode, the processor can be programmed to wake from Hibernate mode by setting the RTCWEN bit in the HIBCTL register. The processor can also be programmed to generate an interrupt to the interrupt controller by setting the RTCALT0 bit in the HIBIM register. The match interrupt generation takes priority over an interrupt clear. Therefore, writes to the RTCALT0 bit in the Hibernation Interrupt Clear (HIBIC) register do not clear the RTCALT0 bit if the HIBRTCC value and the HIBRTCM0 value are equal. There are several methodologies to avoid this occurrence, such as writing a new value to the HIBRTCLD register prior to writing the HIBIC to clear the RTCALT0. Another example, would be to disable the RTC and re-enable the RTC by clearing and setting the RTCEN bit in the HIBCTL register. Note: 7.3.5.3 A Hibernate request made while a match event is valid causes the module to immediately wake up. This occurs when the RTCWEN bit is set and the RTCALT0 bit in the HIBRIS register is set at the same time the HIBREQ bit in the HIBCTL register is written to a 1. This can be avoided by clearing the RTCAL0 bit in the HIBRIS register by writing a 1 to the corresponding bit in the HIBIC register before setting the HIBREQ bit. Another example would be to disable the RTC and re-enable the RTC by clearing and setting the RTCEN bit in the HIBCTL register. RTC Calendar The RTC Calendar function is selected by setting the CALEN bit in the HIB Calendar Control (HIBCALCTL) register. In this mode, six 32-bit registers provide the read (HIBCAL0/1), match (HIBCALM0/1), and load (HIBCALLD0/1) interface. The standard RTC registers: HIBRTCC, HIBRTCLD, HIBRTCSS, and HIBRTCM0 are disabled when the calendar function is enabled and read back as all 0s in this mode. In addition, writes have no effect on these registers when the calendar function is enabled. The Hibernation Calendar n (HIBCALn), Hibernation Calendar Match (HIBCALMn) and Hibernation Calendar Load (HIBCALLDn) register fields are written or stored in hexadecimal. 540 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller When reading the Hibernation Calendar n (HIBCALn) registers, the status of the VALID bit in the HIBCAL0/1 register must be checked to ensure the registers are in sync before reading. The calendar function will keep track of the following: ■ Seconds (0-59 seconds) ■ Minutes (0-59 minutes) ■ Hours (0-23 or 0-11 hours with an AM/PM option) ■ Day of the week (0-6) ■ Day of the month (1-31 days) ■ Month (1-12 months) ■ Year (00-99 years) The hours may be reported with AM/PM or 24-hour based on the CAL24 bit in the HIBCALCTL register. The leap year compensation is handled within the calendar function. The number of days in February are adjusted to 29 whenever the year is divisible by four. RTC Calendar Match The HIB Calendar Match function can be used to generate an interrupt on a match of seconds, minutes, hours, and day of month. The day of the week, year and month are not included in the match function. To ignore a match function for the hours, minutes, or seconds, set each of the upper two bits to 1 in the respective fields of the HIBCALMn register. To ignore the day of the month, set the DOM field to all zeros in the HIBCALM1 register. If a match occurs in any field, the RTCALT0 bit is set in the HIBRIS register. 7.3.5.4 RTC Trim The RTC counting rate can be adjusted to compensate for inaccuracies in the clock source by using the predivider trim register, HIBRTCT. This register has a nominal value of 0x7FFF, and is used for one second out of every 64 seconds in RTC counter mode, when bits [5:0] in the HIBRTCC register change from 0x00 to 0x01, to divide the input clock. Trim is applied every 60 seconds in calendar mode. This configuration allows the software to make fine corrections to the clock rate by adjusting the predivider trim register up or down from 0x7FFF. The predivider trim should be adjusted up from 0x7FFF in order to slow down the RTC rate and down from 0x7FFF in order to speed up the RTC rate. Care must be taken when using trim values that are near to the sub seconds match value in the HIBRTCSS register. It is possible when using trim values above 0x7FFF to receive two match interrupts for the same counter value. In addition, it is possible when using trim values below 0x7FFF to miss a match interrupt. In the case of a trim value above 0x7FFF, when the RTCSSC value in the HIBRTCSS register reaches 0x7FFF, the RTCC value increments from 0x0 to 0x1 while the RTCSSC value is decreased by the trim amount. The RTCSSC value is counted up again to 0x7FFF before rolling over to 0x0 to begin counting up again. If the match value is within this range, the match interrupt is triggered twice. For example, as shown in Figure 7-5 on page 542, if the match interrupt was configured with RTCM0=0x1 and RTCSSM=0x7FFD, two interrupts would be triggered. June 18, 2014 541 Texas Instruments-Production Data Hibernation Module Figure 7-5. Counter Behavior with a TRIM Value of 0x8002 RTCCLK RTCC[6:0] RTCSSC 0x00 0x01 0x7FFD 0x7FFE 0x7FFF 0x7FFD 0x7FFE 0x7FFF 0x02 0x0 0x7FFE 0x7FFF 0x0 0x1 In the case of a trim value below 0x7FFF, the RTCSSC value is advanced from 0x7FFF to the trim value while the RTCC value is incremented from 0x0 to 0x1. If the match value is within that range, the match interrupt is not triggered. For example, as shown in Figure 7-6 on page 542, if the match interrupt was configured with RTCM0=0x1 and RTCSSM=0x2,an interrupt would never be triggered. Figure 7-6. Counter Behavior with a TRIM Value of 0x7FFC RTCCLK RTCC[6:0] RTCSSC 7.3.6 0x00 0x01 0x7FFD 0x7FFE 0x7FFF 0x7FFD 0x7FFE 0x7FFF Tamper The Tamper module provides a user with mechanisms to detect, respond to, and log system tampering events. The Tamper module is designed to be low power and operate either from a battery or the MCU I/O voltage supply. This module is a sub-module of the Hibernate module. 7.3.6.1 Tamper Block Diagram Figure 7-7 on page 542 shows the Tamper block diagram. Figure 7-7. Tamper Block Diagram TMPR[3:0] Tamper Detect and Filter HIBTPIO Control HIBTPCTL HIBTPSTAT Tamper Event NMI BBRAM Clear HIB Wake HIBTPCTL.TPEN XOSC0 XOSC Fail Detector Tamper Log HIBTPLOG HIBTPCTL.TPEN RTC 542 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 7.3.6.2 Functional Description The Tamper module provides mechanisms to detect, respond, and log system tamper events. A tamper event is detected by state transitions on up to four GPIOs. The module may respond to a tamper event by clearing all or part of the hibernate module memory, generating a tamper event signal to the System Control module. The event will also be logged with a RTC time stamp to allow for tamper investigation. Tamper Detection Qualified tamper events are detected through an XOSCn pin failure or through tamper I/O level matches which pass through a glitch filter. Tamper I/O pad events are detected by comparing the level on a tamper I/O pad with an expected value. The tamper I/O is sampled using the hibernate clock source and when the glitch filtering is enabled, must be stable for about 100 ms. This provides debounce filtering of a breakaway switch as a results of a drop impact. The tamper module contains one long glitch filter and one short glitch filter which uses an OR of the inputs as shown in Figure 7-8 on page 543. This implies if two Tamper inputs are asserted and one deasserts, the glitch filter runs to timeout or until the second Tamper input is deasserted. The glitch filter or tamper logging logic does not re-trigger if the tamper event match continues. The glitch filter resets on the deassertion of the tamper conditions or when a qualified tamper event is logged. If the XOSCn pins are enabled for use with the Hibernation module and subsequently fail, a tamper event is detected and is indicated by the STATE field in the HIB Tamper Status (HIBTPSTAT) register. In addition, the XOSCST and XOSCFAIL bits can be read for further details on the external oscillator source state. Figure 7-8. Tamper Pad with Glitch Filtering XOSC0 XOSC Fail Detect Logic TMPR0 Tamper Input Detect LONG FILTER TAMPER EVENT TMPR1 Tamper Input Detect SHORT FILTER TMPR2 Tamper Input Detect TMPR3 Tamper Input Detect Tamper Event Responses There are many responses to a tamper event including clearing some or all of Hibernate memory and generating a tamper signal to the System Control Module. The descriptions of the possible event responses follows. June 18, 2014 543 Texas Instruments-Production Data Hibernation Module ■ Tamper Register Status The tamper status is indicated by the STATE bit field of the HIB Tamper Status (HIBTPSTAT) register. The register bits are reset to 0x0 on cold POR. When the tamper I/O is enabled/configured, the STATE field shows 0x1. The STATE field is set to 0x2 when a tamper event is detected. The software may reset the trigger source and the STATE field by writing to the TPCLR bit in the HIBTPCTL register. ■ System Event Response When a tamper event is detected, an NMI is generated. The NMI handler is responsible for performing any other system responses, including a simulate POR. If the tamper event was an XOSC fail condition, the part switches to the HIB LFIOSC. Once XOSC is stable, the XOSC may be enabled as the clock source once again. ■ Hibernate Memory Clearing On a tamper event, software has the option to clear all, the upper half, lower half, or none of the Hibernate memory. The feature is controlled through the MEMCLR field of the HIBTPCTL register. ■ Wake from Hibernate A tamper event will assert a wake event to the MCU if the WAKE bit in the HIBTPCTL register is set. Tamper Event Logging Up to four tamper events are stored in HIB Tamper Log n (HIBTPLOGn) registers within the Hibernate module. When a tamper event occurs the following status is logged: ■ The RTC seconds or calendar values of year, minutes, day of month, hours and seconds in the HIBTPLOG0/2/4/6 registers Note: 24-hour mode must be used if RTC calendar mode is enabled. This mode is selected by setting the CAL24 bit in HIB Calendar Control (HIBCALCTL) register. ■ The tamper status of the TMPRn pins and the XOSCn pins in the HIBTPLOG1/3/5 registers. The HIBTPLOG7 register captures the OR of all events occurring after the 3rd event is logged in the HIBTPLOG5 register. On the assertion of a qualified tamper event (rising edge) on any of the TMPRn pins or an XOSC failure signal, the current status of all tamper inputs are logged in the HIBTPLOGn register. Clearing a Tamper Event After a tamper event, the HIB Tamper Log (HIBTPLOGn) registers and the NMI to the processor may be cleared by writing a 1 to the TPCLR bit in the HIBTPCTL register. This clear status is reflected by the STATE bit in the HIBSTPSTAT register changing from 0x2 back to a 0x1. If the source of the tamper event comes from an XOSC failure, the clearing of a tamper event is delayed while the clock is switched to LFIOSC. The NMI interrupt handler may access the module immediately, but should read the HIBTPLOGn registers before issuing a tamper clear in the HIBTPCTL register. Note: The HIBTPLOG7 register is sticky and is only cleared by a Hibernate module reset. 544 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Tamper I/O Control Up to four tamper I/Os are available. These signals are individually enabled and the detection level can be configured per pin. Enabling the tamper IO will override all settings made in the GPIO module. Each tamper IO has a weak pull-up. Tamper Clocking The Hibernate clock is the clock source for the Tamper module. When an external oscillator is used and tamper is enabled, the external oscillator is monitored by the Tamper module. If the external oscillator stops for any reason, the XOSCFAIL bit is set in the HIBTPSTAT register and the Hibernate clock source is switched to the HIB LFIOSC immediately. When the XOSCST bit in the HIBTPSTAT register is 0, indicating the external oscillator is active, a 1 can be written to the XOSCFAIL bit to clear it and re-enable the external 32.768-kHz oscillator. Note: Because the HIB LFIOSC has a wide frequency variation, it should not be configured as the HIB clock source when accurate monitoring of the tamper logs are important. Tamper Resets The Tamper module uses the resets from the Hibernate module. Important: The Hibernation module registers are reset under two conditions: 1. Any type of system reset (if the RTCEN and the PINWEN bits in the HIBCTL register are clear and the TPEN bit in the HIBTPCTL register is clear). 2. A cold POR occurs when both the VDD and VBAT supplies are removed. Any other reset condition is ignored by the Hibernation module. 7.3.7 Battery-Backed Memory The Hibernation module contains 16 32-bit words of memory that are powered from the battery or an auxiliary power supply and therefore retained during hibernation. The processor software can save state information in this memory prior to hibernation and recover the state upon waking. To access the upper eight words of memory, the processor must be in privilege mode. Refer to “Processor Mode and Privilege Levels for Software Execution” on page 84 for more information about processor privilege mode. The battery-backed memory can be accessed through the HIBDATA registers. If both VDD and VBAT are removed, the contents of the HIBDATA registers are not retained. 7.3.8 Power Control Using HIB Important: The Hibernation Module requires special system implementation considerations when using HIB to control power, as it is intended to power-down all other sections of the microcontroller. All system signals and power supplies that connect to the chip must be driven to 0 V or powered down with the same regulator controlled by HIB. The Hibernation module controls power to the microcontroller through the use of the HIB pin which is intended to be connected to the enable signal of the external regulator(s) providing 3.3 V to the microcontroller and other circuits. When the HIB signal is asserted by the Hibernation module, the external regulator is turned off and no longer powers the microcontroller and any parts of the system that are powered by the regulator. The Hibernation module remains powered from the VBAT supply until a Wake event. Power to the microcontroller is restored by deasserting the HIB signal, which causes the external regulator to turn power back on to the chip. June 18, 2014 545 Texas Instruments-Production Data Hibernation Module 7.3.9 Power Control Using VDD3ON Mode The Hibernation module may also be configured to cut power to all internal modules during Hibernate mode. While in this state, if VDD3ON is set in the HIBCTL register, all pins are held in the state they were in prior to entering hibernation. For example, inputs remain inputs; outputs driven high remain driven high, and so on. There are important procedural and functional items to note when in VDD3ON mode: ■ JTAG Ports C[0] - C[3] do not retain their state in Hibernate VDD3ON mode. ■ If GPIO pins K[7:4] are not used as a wake source, they should not be left floating. An internal pull-up resistor may be configured by the application before entering Hibernate mode by programming the GPIO Pull-Up Select (GPIOPUR) register in the GPIO module. ■ In the VDD3ON mode, the regulator should maintain 3.3 V power to the microcontroller during Hibernate. GPIO retention is disabled when the RETCLR bit is cleared in the HIBCTL register. ■ When entering hibernation in VDD3ON mode, the supply rails to the Ethernet resistors R1, R2, R3, R4 found in Figure 20-13 on page 1464 must be switched off. 7.3.10 Initiating Hibernate Hibernate mode is initiated when the HIBREQ bit of the HIBCTL register is set. If a wake-up condition has not been configured using the PINWEN or RTCWEN bits in the HIBCTL register, the hibernation request is ignored. In addition, if the battery voltage is below the threshold voltage defined by the VBATSEL field in the HIBCTL register, the hibernation request is ignored. 7.3.11 Waking from Hibernate The Hibernation module can be configured to wake from Hibernate mode if any of the following are enabled: ■ External WAKE ■ External RST ■ GPIO K[7:4] ■ Tamper TMPR[3:0] ■ Tamper XOSC failure The Hibernation module can also be configured to wake from hibernate when the following events occur: ■ RTC match wake event ■ Low Battery wake event The external WAKE pin is enabled by setting the PINWEN bit in the HIBCTL register. The external WAKE pin can generate an interrupt by programming the EXTWEN bit in the Hibernation Interrupt Mask (HIBIM) register. Note: If an external WAKE signal is asserted, the application is responsible for clearing the signal source once the EXTWEN bit has been registered in the Hibernation Raw Interrupt Status (HIBRIS) register. 546 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller To use the RST pin as a wake source, the WURSTEN bit must be set in the Hibernate I/O Configuration (HIBIO) register and the WUUNLK bit must be set in the same register. To enable any of the assigned GPIO pins as a wake source, the WUUNLK bit must be set in the HIBIO register and the wake configuration must be programmed through the GPIOWAKEPEN and GPIOWAKELVL registers in the GPIO module. Please refer to “General-Purpose Input/Outputs (GPIOs)” on page 742 for more information on programming the GPIOs. Note: The RST pin and GPIO wake sources are cleared by a write to either or both the RSTWK and PADIOWK bits. This clears the source of interrupts for RSTWK, PADIOWK and the GPIOWAKESTAT register. TMPR[3:0] are enabled by setting the appropriate ENn bits the Tamper IO Control and Status (HIBTPIO) register. The HIBTPIO register overrides the GPIO port configuration registers. By setting the WAKE bit in the Tamper Control (HIBTPCTL) register, a tamper event can cause a wake from Hibernate. If a tamper event occurs, the time of the event and the status of the tamper pins are logged in the Tamper Log (HIBTPLOG) register. By setting the RTCWEN bit in the HIBCTL register a wake from hibernate can occur when the value of the HIBRTCC register matches the value of the HIBRTCM0 register and the value of the RTCSSC field matches the RTCSSM field in the HIBRTCSS register. To allow a wake from Hibernate on a low battery event, the BATWKEN bit in the HIBCTL register must be set. In this configuration, the battery voltage is checked every 512 seconds while in hibernation. If the voltage is below the level specified by the VBATSEL field, the LOWBAT interrupt is set in the HIBRIS register. Upon external wake-up, external reset, tamper event, or RTC match, the Hibernation module delays coming out of hibernation until VDD is above the minimum specified voltage, see Table 27-6 on page 1820. When the Hibernation module wakes, the microcontroller performs a normal power-on reset. The normal power-on reset does not reset the Hibernation module or Tamper module, but does reset the rest of the microcontroller. Software can detect that the power-on was due to a wake from hibernation by examining the raw interrupt status register (see “Interrupts and Status” on page 548) and by looking for state data in the battery-backed memory (see “Battery-Backed Memory” on page 545). 7.3.12 Arbitrary Power Removal The microcontroller goes into hibernation if VDD is arbitrarily removed when the CLK32EN bit is set and any of the following bits are set: ■ TPEN bit in the HIBTPCTL register ■ PINWEN bit in the HIBCTL register ■ RTCEN bit in the HIBCTL register The microcontroller wakes from hibernation when power is reapplied. If the CLK32EN bit is set but the TPEN, PINWEN, and RTCEN bits are all clear, the microcontroller still goes into hibernation if power is removed; however, when VDD is reapplied, the MCU executes a cold POR and the Hibernation module is reset. If the CLK32EN bit is not set and VDD is arbitrarily removed, the part is simply powered off and executes a cold POR when power is reapplied. June 18, 2014 547 Texas Instruments-Production Data Hibernation Module If VDD is arbitrarily removed while a Flash memory or HIBDATA register write operation is in progress, the write operation must be retried after VDD is reapplied. 7.3.13 Interrupts and Status The Hibernation module can generate interrupts when the following conditions occur: ■ Assertion of WAKE pin ■ RTC match ■ Low battery detected ■ Write complete/capable ■ Assertion of an external RESET pin ■ Assertion of an external wake-enabled GPIO pin (port K[7:4]]) All of the interrupts except for the tamper signals are ORed together before being sent to the interrupt controller, so the Hibernate module can only generate a single interrupt request to the controller at any given time. The software interrupt handler can service multiple interrupt events by reading the Hibernation Masked Interrupt Status (HIBMIS) register. Software can also read the status of the Hibernation module at any time by reading the HIBRIS register which shows all of the pending events. This register can be used after waking from hibernation to see if a wake condition was caused by one of the events above or by a power loss. The WAKE pin can generate interrupts in Run, Sleep and Deep Sleep Mode. The events that can trigger an interrupt are configured by setting the appropriate bits in the Hibernation Interrupt Mask (HIBIM) register. Pending interrupts can be cleared by writing the corresponding bit in the Hibernation Interrupt Clear (HIBIC) register. 7.4 Initialization and Configuration The Hibernation module has several different configurations. The following sections show the recommended programming sequence for various scenarios. Because the Hibernation module runs at a low frequency and is asynchronous to the rest of the microcontroller, which is run off the system clock, software must allow a delay of tHIB_REG_ACCESS after writes to registers (see “Register Access Timing” on page 535). The WC interrupt in the HIBMIS register can be used to notify the application when the Hibernation modules registers can be accessed. 7.4.1 Initialization The Hibernation module comes out of reset with the system clock enabled to the module, but if the system clock to the module has been disabled, then it must be re-enabled, even if the RTC feature is not used. See page 387. If a 32.768-kHz crystal is used as the Hibernation module clock source, perform the following steps: 1. Write 0x0000.0010 to the HIBIM register to enable the WC interrupt. 2. Write 0x40 to the HIBCTL register at offset 0x10 to enable the oscillator input. 3. Wait until the WC interrupt in the HIBMIS register has been triggered before performing any other operations with the Hibernation module. 548 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller If a 32.768-kHz single-ended oscillator is used as the Hibernation module clock source, then perform the following steps: 1. Write 0x0000.0010 to the HIBIM register to enable the WC interrupt. 2. Write 0x0001.0040 to the HIBCTL register at offset 0x10 to enable the oscillator input and bypass the on-chip oscillator. 3. Wait until the WC interrupt in the HIBMIS register has been triggered before performing any other operations with the Hibernation module. If the internal low frequency oscillator is used as the Hibernation module clock source, then perform the following steps: 1. Write 0x0000.0010 to the HIBIM register to enable the WC interrupt. 2. Write 0x0008.0040 to the HIBCTL register at offset 0x10 to enable the internal low frequency oscillator. 3. Wait until the WC interrupt in the HIBMIS register has been triggered before performing any other operations with the Hibernation module. The above steps are only necessary when the entire system is initialized for the first time. If the microcontroller has been in hibernation, then the Hibernation module has already been powered up and the above steps are not necessary. The software can detect that the Hibernation module and clock are already powered by examining the CLK32EN bit of the HIBCTL register. 7.4.2 RTC Match Functionality (No Hibernation) Use the following steps to implement the RTC match functionality of the Hibernation module: 1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation oscillator. 2. Write the required RTC match value to the HIBRTCM0 register at offset 0x004 and the RTCSSM field in the HIBRTCSS register at offset 0x028. 3. Write the required RTC load value to the HIBRTCLD register at offset 0x00C. 4. Set the required RTC match interrupt mask in the RTCALT0 in the HIBIM register at offset 0x014. 5. Write 0x0000.0041 to the HIBCTL register at offset 0x010 to enable the RTC to begin counting. 7.4.3 RTC Match/Wake-Up from Hibernation Use the following steps to implement the RTC match and wake-up functionality of the Hibernation module: 1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation oscillator. 2. Write the required RTC match value to the HIBRTCM0 register at offset 0x004 and the RTCSSM field in the HIBRTCSS register at offset 0x028. 3. Write the required RTC load value to the HIBRTCLD register at offset 0x00C. This write causes the 15-bit sub seconds counter to be cleared. June 18, 2014 549 Texas Instruments-Production Data Hibernation Module 4. Write any data to be retained during hibernation to the HIBDATA register at offsets 0x030-0x06F. 5. Set the RTC Match Wake-Up and start the hibernation sequence by writing 0x0000.004B to the HIBCTL register at offset 0x010. 7.4.4 External Wake-Up from Hibernation Use the following steps to implement the Hibernation module with the external WAKE pin as the wake-up source for the microcontroller: 1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation oscillator. 2. Write any data to be retained during hibernation to the HIBDATA register at offsets 0x030-0x06F. 3. Enable the external wake and start the hibernation sequence by writing 0x0000.0052 to the HIBCTL register at offset 0x010. Use the following steps to program the external RESET pin as the wake source for the microcontroller: 1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation oscillator. 2. Write any data to be retained during hibernation to the HIBDATA register at offsets 0x030-0x06F. 3. Enable the external RESET pin as a wake source by writing a 0x0000.0011 to the HIBIO register at offset 0x02C. 4. When the IOWRC bit in the HIBIO register is read as 1, clear the WUUNLK bit in the HIBIO register to lock the current pad configuration so that any other writes to the WURSTEN bit in the HIBIO register will be ignored. 5. The hibernation sequence may be initiated by writing 0x4000.0152 to the HIBCTL register. Note that when using RESET, the user must enable VDD3ON mode and set the RETCLR bit in the HIBCTL register. Use the following steps to program GPIO port K pins K[7:4] as the wake source for the microcontroller: 1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation oscillator. 2. Write any data to be retained during hibernation to the HIBDATA register at offsets 0x030-0x06F. 3. Configure the GPIOWAKEPEN and GPIOWAKELVL registers at offsets 0x540 and 0x544 in the GPIO module. Enable the I/O wake pad configuration by writing 0x0000.0001 to the HIBIO register at offset 0x010. 4. When the IOWRC bit in the HIBIO register is read as 1, write 0x0000.0000 to the HIBIO register to lock the current pad configuration so that any other writes to the GPIOWAKEPEN and GPIOWAKELVL register will be ignored. 5. Clear any pending interrupts by writing a 1 to the PADIOWK bit in the HIBIC register. 550 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 6. The hibernation sequence may be initiated by writing 0x4000.0152 to the HIBCTL register. Note for Port M external wake, the user must enable VDD3ON mode and set the RETCLR bit in the HIBCTL register. 7.4.5 RTC or External Wake-Up from Hibernation 1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation oscillator. 2. Write the required RTC match value to the HIBRTCM0 register at offset 0x004 and the RTCSSM field in the HIBRTCSS register at offset 0x028. 3. Write the required RTC load value to the HIBRTCLD register at offset 0x00C. This write causes the 15-bit sub seconds counter to be cleared. 4. Write any data to be retained during hibernation to the HIBDATA register at offsets 0x030-0x06F. 5. Set the RTC Match/External Wake-Up and start the hibernation sequence by writing 0x0000.005B to the HIBCTL register at offset 0x010. 7.4.6 Tamper Initialization Use the following steps to configure the Tamper module to interrupt the processor when a TMPR signal has triggered: Note: Unlike other functions, the Tamper pins do not need to be configured for the GPIO in the GPIOAFSEL register. The Tamper IO Control and Status (HIBTPIO) register overrides configurations made to the GPIO module. 1. Write 0x0000.0041 to the HIBCTL register at offset 0x010 to enable the 32.768-kHz Hibernate oscillator and enable the RTC. 2. Enable the four Tamper I/O to trigger on the a high state on any of the pins by writing 0x0F0F.0F0F to the HIBTPIO register at offset 0x410. 3. Write 0x0000.0001 to the HIBTPCTL register to enable the tamper. Note: Once tamper is enabled, the following HIBCTL register bits are locked and cannot be modified: ■ ■ ■ ■ ■ ■ 7.5 OSCSEL OSCDRV OSCBYP VDD3ON CLK32EN RTCEN Register Map Table 7-3 on page 552 lists the Hibernation registers. All addresses given are relative to the Hibernation Module base address at 0x400F.C000. Note that the system clock to the Hibernation module must be enabled before the registers can be programmed (see page 387). There must be a delay of 3 system clocks after the Hibernation module clock is enabled before any Hibernation module registers June 18, 2014 551 Texas Instruments-Production Data Hibernation Module are accessed. In addition, the CLK32EN bit in the HIBCTL register must be set before accessing any other Hibernation module register. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Important: The Hibernation module registers are reset under two conditions: 1. Any type of system reset (if the RTCEN and the PINWEN bits in the HIBCTL register are clear and the TPEN bit in the HIBTPCTL register is clear). 2. A cold POR occurs when both the VDD and VBAT supplies are removed. Any other reset condition is ignored by the Hibernation module. Note that the following registers are only accessed through privileged mode (see “System Control” on page 220 for more details): ■ HIBTPCTL ■ HIBPTSTAT ■ HIBTPIO ■ HIBTPLOG ■ Upper eight words of memory (HIBDATA register 0x50 to 0x6F) Table 7-3. Hibernation Module Register Map Offset Name 0x000 Description See page Type Reset HIBRTCC RO 0x0000.0000 Hibernation RTC Counter 554 0x004 HIBRTCM0 RW 0xFFFF.FFFF Hibernation RTC Match 0 555 0x00C HIBRTCLD WO 0x0000.0000 Hibernation RTC Load 556 0x010 HIBCTL RW 0x8000.2000 Hibernation Control 557 0x014 HIBIM RW 0x0000.0000 Hibernation Interrupt Mask 562 0x018 HIBRIS RO 0x0000.0000 Hibernation Raw Interrupt Status 564 0x01C HIBMIS RO 0x0000.0000 Hibernation Masked Interrupt Status 566 0x020 HIBIC RW1C 0x0000.0000 Hibernation Interrupt Clear 568 0x024 HIBRTCT RW 0x0000.7FFF Hibernation RTC Trim 570 0x028 HIBRTCSS RW 0x0000.0000 Hibernation RTC Sub Seconds 571 552 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 7-3. Hibernation Module Register Map (continued) Offset Name Type Reset 0x02C HIBIO RW 0x8000.0000 0x0300x06F HIBDATA RW - 0x300 HIBCALCTL RW 0x310 HIBCAL0 0x314 Description See page Hibernation IO Configuration 572 Hibernation Data 574 0x0000.0000 Hibernation Calendar Control 575 RO 0x0000.0000 Hibernation Calendar 0 576 HIBCAL1 RO 0x0000.0000 Hibernation Calendar 1 578 0x320 HIBCALLD0 WO 0x0000.0000 Hibernation Calendar Load 0 580 0x324 HIBCALLD1 WO 0x0000.0000 Hibernation Calendar Load 582 0x330 HIBCALM0 RW 0x0000.0000 Hibernation Calendar Match 0 583 0x334 HIBCALM1 RW 0x0000.0000 Hibernation Calendar Match 1 585 0x360 HIBLOCK RW 0x0000.0000 Hibernation Lock 586 0x400 HIBTPCTL RW 0x0000.0000 HIB Tamper Control 587 0x404 HIBTPSTAT RW1C 0x0000.0000 HIB Tamper Status 589 0x410 HIBTPIO RW 0x0000.0000 HIB Tamper I/O Control 591 0x4E0 HIBTPLOG0 RO 0x0000.0000 HIB Tamper Log 0 595 0x4E4 HIBTPLOG1 RO 0x0000.0000 HIB Tamper Log 1 596 0x4E8 HIBTPLOG2 RO 0x0000.0000 HIB Tamper Log 2 595 0x4EC HIBTPLOG3 RO 0x0000.0000 HIB Tamper Log 3 596 0x4F0 HIBTPLOG4 RO 0x0000.0000 HIB Tamper Log 4 595 0x4F4 HIBTPLOG5 RO 0x0000.0000 HIB Tamper Log 5 596 0x4F8 HIBTPLOG6 RO 0x0000.0000 HIB Tamper Log 6 595 0x4FC HIBTPLOG7 RO 0x0000.0000 HIB Tamper Log 7 596 0xFC0 HIBPP RO 0x0000.0002 Hibernation Peripheral Properties 598 0xFC8 HIBCC RW 0x0000.0000 Hibernation Clock Control 599 7.6 Register Descriptions The remainder of this section lists and describes the Hibernation module registers, in numerical order by address offset. June 18, 2014 553 Texas Instruments-Production Data Hibernation Module Register 1: Hibernation RTC Counter (HIBRTCC), offset 0x000 This register is the current 32-bit value of the RTC counter. The RTC counter consists of a 32-bit seconds counter and a 15-bit sub seconds counter. The RTC counters are reset by the Hibernation module reset. The RTC 32-bit seconds counter can be set by the user using the HIBRTCLD register. When the 32-bit seconds counter is set, the 15-bit sub second counter is cleared. The RTC value can be read by first reading the HIBRTCC register, reading the RTCSSC field in the HIBRTCSS register, and then rereading the HIBRTCC register. If the two values for HIBRTCC are equal, the read is valid. Note: There is a minimum system clock rate of three times the HIB clock rate to properly read the HIBRTCC register. Hibernation RTC Counter (HIBRTCC) Base 0x400F.C000 Offset 0x000 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RTCC Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RTCC Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type 31:0 RTCC RO RO 0 Reset RO 0 Description 0x0000.0000 RTC Counter A read returns the 32-bit counter value, which represents the seconds elapsed since the RTC was enabled. This register is read-only. To change the value, use the HIBRTCLD register. 554 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: Hibernation RTC Match 0 (HIBRTCM0), offset 0x004 This register is the 32-bit seconds match register for the RTC counter. The 15-bit sub second match value is stored in the reading the RTCSSC field in the HIBRTCSS register and can be used in conjunction with this register for a more precise time match. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Hibernation RTC Match 0 (HIBRTCM0) Base 0x400F.C000 Offset 0x004 Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RTCM0 Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RTCM0 Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 Bit/Field Name Type 31:0 RTCM0 RW RW 1 Reset RW 1 Description 0xFFFF.FFFF RTC Match 0 A write loads the value into the RTC match register. A read returns the current match value. June 18, 2014 555 Texas Instruments-Production Data Hibernation Module Register 3: Hibernation RTC Load (HIBRTCLD), offset 0x00C This register is used to load a 32-bit value loaded into the RTC counter. The load occurs immediately upon this register being written. When this register is written, the 15-bit sub seconds counter is also cleared. Note: This register is protected from errant code by using the HIBLOCK register. This register is write-only; any reads to this register read back as zeros. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Hibernation RTC Load (HIBRTCLD) Base 0x400F.C000 Offset 0x00C Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RTCLD Type Reset WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 RTCLD Type Reset WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 Bit/Field Name Type 31:0 RTCLD WO WO 0 Reset WO 0 Description 0x0000.0000 RTC Load A write loads the current value into the RTC counter (RTCC). A read returns the 32-bit load value. 556 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 4: Hibernation Control (HIBCTL), offset 0x010 This register is the control register for the Hibernation module. This register must be written last before a hibernate event is issued. Writes to other registers after the HIBREQ bit is set are not guaranteed to complete before hibernation is entered. Note: Writes to this register have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required synchronization has elapsed. While the WRC bit is clear, any attempts to write this register are ignored. Reads may occur at any time. Note that once tamper is enabled, the following HIBCTL clock configuration bits and bus write stall bit are locked and cannot be modified: ■ ■ ■ ■ ■ ■ OSCSEL OSCDRV OSCBYP VDD3ON CLK32EN RTCEN Hibernation Control (HIBCTL) Base 0x400F.C000 Offset 0x010 Type RW, reset 0x8000.2000 Type Reset 31 30 29 28 27 26 25 WRC RETCLR RO 1 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 reserved Type Reset RO 0 23 22 21 20 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RO 0 RW 0 RW 0 8 7 6 5 4 3 2 1 0 HIBREQ RTCEN RW 0 RW 0 reserved VBATSEL RW 0 24 reserved RW 1 RO 0 19 18 RW 0 RW 0 Bit/Field Name Type Reset 31 WRC RO 1 16 OSCSEL reserved OSCDRV OSCBYP BATCHK BATWKEN VDD3ON VABORT CLK32EN reserved PINWEN RTCWEN reserved RO 0 17 RW 0 RW 0 RW 0 RO 0 RW 0 RW 0 RO 0 Description Write Complete/Capable Value Description 0 The interface is processing a prior write and is busy. Any write operation that is attempted while WRC is 0 results in undetermined behavior. 1 The interface is ready to accept a write. Software must poll this bit between write requests and defer writes until WRC=1 to ensure proper operation. An interrupt can be configured to indicate the WRC has completed. The bit name WRC means "Write Complete," which is the normal use of the bit (between write accesses). However, because the bit is set out-of-reset, the name can also mean "Write Capable" which simply indicates that the interface may be written to by software. This difference may be exploited by software at reset time to detect which method of programming is appropriate: 0 = software delay loops required; 1 = WRC paced available. June 18, 2014 557 Texas Instruments-Production Data Hibernation Module Bit/Field Name Type Reset 30 RETCLR RW 0 Description GPIO Retention/Clear This bit is used when the VDD3ON bit is set.This bit is must be set when entering the hibernate state when the VDD3ON bit is set. This does not affect behavior when VDD3ON is clear. Note: This bit must be set when enabling VDD3ON mode. Value Description 0 GPIO retention is released when power is reapplied. The GPIOs are initialized to default values. 1 GPIO retention set until software clears this bit. 29:20 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 OSCSEL RW 0 Oscillator Select This bit is used to select between the use of an external 32.768-kHz source or the HIB internal low frequency oscillator (HIB LFIOSC). Note: To enable the HIB LFIOSC, CLK32EN must be programmed to 1 at the same time the OSCSEL bit is set. Thus the HIBCTL register should be written with 0x0008.0040 Value Description 0 External 32.786-kHZ clock source is enabled. 1 HIB Low frequency oscillator (HIB LFIOSC) is enabled. Note: The HIB low-frequency oscillator has a wide frequency variation, therefore the RTC is not accurate when using this clock source. 18 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 17 OSCDRV RW 0 Oscillator Drive Capability This bit is used to compensate for larger or smaller filtering capacitors. Note: This bit is not meant to be changed once the Hibernation oscillator has started. Oscillator stability is not guaranteed if the user changes this value after the oscillator is running. Value Description 16 OSCBYP RW 0 0 Low drive strength is enabled, 12 pF. 1 High drive strength is enabled, 24 pF. Oscillator Bypass Value Description 0 The internal 32.768-kHz Hibernation oscillator is enabled. This bit should be cleared when using an external 32.768-kHz crystal. 1 The internal 32.768-kHz Hibernation oscillator is disabled and powered down. This bit should be set when using a single-ended oscillator attached to XOSC0. 558 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 15 reserved RO 0 14:13 VBATSEL RW 0x1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Select for Low-Battery Comparator This field selects the battery level that is used when checking the battery status. If the battery voltage is below the specified level, the LOWBAT interrupt bit in the HIBRIS register is set. Value Description 12:11 reserved RO 0x0 10 BATCHK RW 0 0x0 1.9 Volts 0x1 2.1 Volts (default) 0x2 2.3 Volts 0x3 2.5 Volts Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Check Battery Status Value Description 0 When read, indicates that the low-battery comparator cycle is not active. Writing a 0 has no effect. 1 When read, indicates the low-battery comparator cycle has not completed. Setting this bit initiates a low-battery comparator cycle. If the battery voltage is below the level specified by VBATSEL field, the LOWBAT interrupt bit in the HIBRIS register is set. A hibernation request is held off if a battery check is in progress. 9 BATWKEN RW 0 Wake on Low Battery Value Description 0 The battery voltage level is not automatically checked. Low battery voltage does not cause the microcontroller to wake from hibernation. 1 In RTC mode, when this bit is set, the battery voltage level is checked every 512 seconds while in hibernation. In calendar mode, the battery voltage is checked on minutes divisible by 8 while in hibernation. If the voltage is below the level specified by VBATSEL field, the microcontroller wakes from hibernation and the LOWBAT interrupt bit in the HIBRIS register is set. June 18, 2014 559 Texas Instruments-Production Data Hibernation Module Bit/Field Name Type Reset 8 VDD3ON RW 0 Description VDD Powered Value Description 0 The internal switches are not used. The HIB signal should be used to control an external switch or regulator. 1 The internal switches control the power to the on-chip modules (VDD3ON mode). Regardless of the status of the VDD3ON bit, the HIB signal is asserted during Hibernate mode. Thus, when VDD3ON is set, the HIB signal should not be connected to the 3.3V regulator, and the 3.3V power source should remain connected. When this bit is set while in hibernation, all pins are held in the state they were in prior to entering hibernation. For example, inputs remain inputs; outputs driven high remain driven high, and so on. Ports retain their state in VDD3ON mode until the RETCLR bit is cleared. The RETCLR bit must be set when the VDD3ON bit is set. 7 6 VABORT CLK32EN RW RW 0 0 Power Cut Abort Enable Value Description 0 The microcontroller goes into hibernation regardless of the voltage level of the battery. 1 When this bit is set, the battery voltage level is checked before entering hibernation. If VBAT is less than the voltage specified by VBATSEL, the microcontroller does not go into hibernation. Clocking Enable This bit must be enabled to use the Hibernation module. Value Description 0 The Hibernation module clock source is disabled. 1 The Hibernation module clock source is enabled. 5 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 PINWEN RW 0 External Wake and Interrupt Pin Enable Value Description 0 The status of the WAKE or an external I/O wake pad source pin has no effect on hibernation. 1 An assertion of the WAKE pin or an external I/O wake pad source takes the microcontroller out of hibernation. An external I/O wake pad interrupt may be generated in active mode. Note: The external I/O wake pad interrupt is set if the WAKE pin is asserted in Run, Sleep, or Deep Sleep mode regardless of whether the PINWEN bit is 0x0 or 0x1. The interrupt may be forwarded to the processor by setting the EXTW bit in the HIBIM register. 560 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 RTCWEN RW 0 Description RTC Wake-up Enable Value Description 0 An RTC match event has no effect on hibernation. 1 An RTC match event (the value the HIBRTCC register matches the value of the HIBRTCM0 register and the value of the RTCSSC field matches the RTCSSM field in the HIBRTCSS register) takes the microcontroller out of hibernation. 2 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1 HIBREQ RW 0 Hibernation Request Value Description 0 No hibernation request. 1 Set this bit to initiate hibernation. After a wake-up event, this bit is automatically cleared by hardware. A hibernation request is ignored if both the PINWEN and RTCWEN bits are clear. 0 RTCEN RW 0 RTC Timer/Calendar Enable This is bit must be set to enable RTC or calendar mode. For calendar mode enable, the CALEN bit in the HIBCALCTL register must also be set. Value Description 0 The Hibernation module RTC and calendar mode are disabled. 1 The Hibernation module RTC and calendar mode are enabled. Note: The low-frequency oscillator has a wide frequency variation, therefore the RTC is not accurate when using this clock source. June 18, 2014 561 Texas Instruments-Production Data Hibernation Module Register 5: Hibernation Interrupt Mask (HIBIM), offset 0x014 This register is the interrupt mask register for the Hibernation module interrupt sources. Each bit in this register masks the corresponding bit in the Hibernation Raw Interrupt Status (HIBRIS) register. If a bit is unmasked, the interrupt is sent to the interrupt controller. If the bit is masked, the interrupt is not sent to the interrupt controller. The WC bit of the HIBIM register may be set before the CLK32EN bit of the HIBCTL register is set. This allows software to use the WC interrupt trigger to detect when the RTCOSC clock is stable, which may be in excess of one second. If the WC bit is set before the CLK32EN has been set, the mask value is not preserved over a hibernate cycle unless the bit is written a second time. Note: The WC bit of this register is in the system clock domain such that a write to this bit is immediate and may be done before the CLK32EN bit is set in the HIBCTL register. Hibernation Interrupt Mask (HIBIM) Base 0x400F.C000 Offset 0x014 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 WC EXTW RW 0 RW 0 reserved Type Reset reserved Type Reset VDDFAIL RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.000 7 VDDFAIL RW 0 RW 0 RSTWK PADIOWK RW 0 RW 0 LOWBAT reserved RTCALT0 RW 0 RO 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. VDD Fail Interrupt Mask Value Description 6 RSTWK RW 0 0 The VDDFAIL interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the VDDFAIL bit in the HIBRIS register is set. Reset Pad I/O Wake-Up Interrupt Mask Value Description 0 The RSTWK interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the RSTWK bit in the HIBRIS register is set. 562 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 5 PADIOWK RW 0 Description Pad I/O Wake-Up Interrupt Mask Value Description 4 WC RW 0 0 The PADIOWK interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PADIOWK bit in the HIBRIS register is set. External Write Complete/Capable Interrupt Mask Value Description 3 EXTW RW 0 0 The WC interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the WC bit in the HIBRIS register is set. External Wake-Up Interrupt Mask Value Description 2 LOWBAT RW 0 0 The EXTW interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the EXTW bit in the HIBRIS register is set. Low Battery Voltage Interrupt Mask Value Description 0 The LOWBAT interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the LOWBAT bit in the HIBRIS register is set. 1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 RTCALT0 RW 0 RTC Alert 0 Interrupt Mask Value Description 0 The RTCALT0 interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the RTCALT0 bit in the HIBRIS register is set. June 18, 2014 563 Texas Instruments-Production Data Hibernation Module Register 6: Hibernation Raw Interrupt Status (HIBRIS), offset 0x018 This register is the raw interrupt status for the Hibernation module interrupt sources. Each bit can be masked by clearing the corresponding bit in the HIBIM register. When a bit is masked, the interrupt is not sent to the interrupt controller. Bits in this register are cleared by writing a 1 to the corresponding bit in the Hibernation Interrupt Clear (HIBIC) register or by entering hibernation. Hibernation Raw Interrupt Status (HIBRIS) Base 0x400F.C000 Offset 0x018 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 WC EXTW RO 0 RO 0 reserved Type Reset reserved Type Reset VDDFAIL RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.000 7 VDDFAIL RO 0 RO 0 RSTWK PADIOWK RO 0 RO 0 LOWBAT reserved RTCALT0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. VDD Fail Raw Interrupt Status Value Description 6 RSTWK RO 0 0 No VDDFAIL interrupt condition exists. 1 An interrupt is sent to the interrupt controller because of arbitrary power removal or because one or more of the supplies (VDD, VDDA or VDDC) has dropped below the defined operating range. Reset Pad I/O Wake-Up Raw Interrupt Status Value Description 5 PADIOWK RO 0 0 The RESET pin has not been asserted or has not been enabled to wake the device from hibernation. 1 An interrupt is sent to the interrupt controller because the RESET pin has been programmed to wake the device from hibernation. Pad I/O Wake-Up Raw Interrupt Status Value Description 0 One of the wake-enabled GPIO pins or the external RESET pin has not been asserted or has not been enabled to wake the device from hibernation. 1 An interrupt is sent to the interrupt controller because one of the wake-enabled GPIO pins or the external RESET pin has been asserted. 564 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 WC RO 0 Description Write Complete/Capable Raw Interrupt Status Value Description 0 The WRC bit in the HIBCTL has not been set. 1 The WRC bit in the HIBCTL has been set. This bit is cleared by writing a 1 to the WC bit in the HIBIC register. 3 EXTW RO 0 External Wake-Up Raw Interrupt Status Note that a wake signal source must be cleared by the application after the interrupt has been registered. Value Description 0 The WAKE pin has not been asserted. 1 The WAKE pin has been asserted. This bit is cleared by writing a 1 to the EXTW bit in the HIBIC register. Note: 2 LOWBAT RO 0 The EXTW bit is set if the WAKE pin is asserted in any mode of operation (Run, Sleep, Deep Sleep) regardless of whether the PINWEN bit is set in the HIBCTL register. Low Battery Voltage Raw Interrupt Status Value Description 0 The battery voltage has not dropped below VLOWBAT. 1 The battery voltage dropped below VLOWBAT. This bit is cleared by writing a 1 to the LOWBAT bit in the HIBIC register. 1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 RTCALT0 RO 0 RTC Alert 0 Raw Interrupt Status Value Description 0 No match 1 If the RTC is enabled, t he value of the HIBRTCC register matches the value in the HIBRTCM0 register and the value of the RTCSSC field matches the RTCSSM field in the HIBRTCSS register. If the Calendar function is enabled, this interrupt status indicates that one or more of the allowed fields in the HIBCAL0/1 register matches in the HIBCALM0/1 register.. This bit is cleared by writing a 1 to the RTCALT0 bit in the HIBIC register. June 18, 2014 565 Texas Instruments-Production Data Hibernation Module Register 7: Hibernation Masked Interrupt Status (HIBMIS), offset 0x01C This register is the masked interrupt status for the Hibernation module interrupt sources. Bits in this register are the AND of the corresponding bits in the HIBRIS and HIBIM registers. When both corresponding bits are set, the bit in this register is set, and the interrupt is sent to the interrupt controller. Hibernation Masked Interrupt Status (HIBMIS) Base 0x400F.C000 Offset 0x01C Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 WC EXTW RO 0 RO 0 reserved Type Reset reserved Type Reset VDDFAIL RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.000 7 VDDFAIL RO 0 RO 0 RSTWK PADIOWK RO 0 RO 0 LOWBAT reserved RTCALT0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. VDD Fail Interrupt Mask Value Description 6 RSTWK RO 0 0 An VDDFAIL interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a an arbitrary loss of power or because on or more of the voltage supplies (VDD, VDDA or VDDC) has dropped below the defined operating range. Reset Pad I/O Wake-Up Interrupt Mask Value Description 5 PADIOWK RO 0 0 An external reset interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a RESET pin assertion. Pad I/O Wake-Up Interrupt Mask Value Description 0 An external GPIO or reset interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a wake-enabled GPIO or RESET pin assertion. 566 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 WC RO 0 Description Write Complete/Capable Masked Interrupt Status Value Description 0 The WRC bit has not been set or the interrupt is masked. 1 An unmasked interrupt was signaled due to the WRC bit being set. This bit is cleared by writing a 1 to the WC bit in the HIBIC register. 3 EXTW RO 0 External Wake-Up Masked Interrupt Status Value Description 0 An external wake-up interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a WAKE pin assertion. This bit is cleared by writing a 1 to the EXTW bit in the HIBIC register. 2 LOWBAT RO 0 Low Battery Voltage Masked Interrupt Status Value Description 0 A low-battery voltage interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a low-battery voltage condition. This bit is cleared by writing a 1 to the LOWBAT bit in the HIBIC register. 1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 RTCALT0 RO 0 RTC Alert 0 Masked Interrupt Status Note: The MIS may apply to either the RTC or calendar block depending on which is enabled. Value Description 0 An RTC or calendar match interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to an RTC or calendar match. This bit is cleared by writing a 1 to the RTCALT0 bit in the HIBIC register. June 18, 2014 567 Texas Instruments-Production Data Hibernation Module Register 8: Hibernation Interrupt Clear (HIBIC), offset 0x020 This register is the interrupt write-one-to-clear register for the Hibernation module interrupt sources. Writing a 1 to a bit clears the corresponding interrupt in the HIBRIS register. Note: Writes to the RSTWK, PADIOWK and WC bits of this register are immediate and the status may be read from the HIBRIS and HIBMIS registers without monitoring the WRC bit of the HIBCTL register. Note: All I/O wake sources are cleared by a write to either or both the RSTWK and PADIOWK bits. This clears the source of interrupts for RSTWK, PADIOWK and the GPIOWAKESTAT register. Hibernation Interrupt Clear (HIBIC) Base 0x400F.C000 Offset 0x020 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 reserved Type Reset reserved Type Reset VDDFAIL RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.000 7 VDDFAIL RW1C 0 RW1C 0 RSTWK PADIOWK RW1C 0 RW1C 0 WC EXTW RW1C 0 RW1C 0 LOWBAT reserved RTCALT0 RW1C 0 RO 0 RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. VDD Fail Interrupt Clear Writing a 1 to this bit clears the VDDFAIL bit in the HIBRIS and HIBMIS registers. Reads return the raw interrupt status. 6 RSTWK RW1C 0 Reset Pad I/O Wake-Up Interrupt Clear Writing a 1 to this bit clears the RSTWK bit in the HIBRIS and HIBMIS registers. Reads return the raw interrupt status. 5 PADIOWK RW1C 0 Pad I/O Wake-Up Interrupt Clear Writing a 1 to this bit clears the PADIOWK bit in the HIBRIS and HIBMIS registers. Reads return the raw interrupt status. 4 WC RW1C 0 Write Complete/Capable Interrupt Clear Writing a 1 to this bit clears the WC bit in the HIBRIS and HIBMIS registers. Reads return the raw interrupt status. 3 EXTW RW1C 0 External Wake-Up Interrupt Clear Writing a 1 to this bit clears the EXTW bit in the HIBRIS and HIBMIS registers. Reads return the raw interrupt status. 568 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2 LOWBAT RW1C 0 Description Low Battery Voltage Interrupt Clear Writing a 1 to this bit clears the LOWBAT bit in the HIBRIS and HIBMIS registers. Reads return the raw interrupt status. 1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 RTCALT0 RW1C 0 RTC Alert0 Masked Interrupt Clear Writing a 1 to this bit clears the RTCALT0 bit in the HIBRIS and HIBMIS registers. Reads return the raw interrupt status. Note: The timer interrupt source cannot be cleared if the RTC value and the HIBRTCM0 register / RTCMSS field values are equal. The match interrupt takes priority over the interrupt clear. June 18, 2014 569 Texas Instruments-Production Data Hibernation Module Register 9: Hibernation RTC Trim (HIBRTCT), offset 0x024 This register contains the value that is used to trim the RTC clock predivider. It represents the computed underflow value that is used during the trim cycle. It is represented as 0x7FFF ± N clock cycles, where N is the number of clock cycles to add or subtract every 64 seconds in RTC mode or 60 seconds in calendar mode. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Hibernation RTC Trim (HIBRTCT) Base 0x400F.C000 Offset 0x024 Type RW, reset 0x0000.7FFF 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 reserved Type Reset TRIM Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 TRIM RW 0x7FFF RTC Trim Value This value is loaded into the RTC predivider every 64 seconds in RTC counter mode. In calendar mode, the value is loaded every 60 seconds. It is used to adjust the RTC rate to account for drift and inaccuracy in the clock source. Compensation can be adjusted by software by moving the default value of 0x7FFF up or down. Moving the value up slows down the RTC and moving the value down speeds up the RTC. 570 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 10: Hibernation RTC Sub Seconds (HIBRTCSS), offset 0x028 This register contains the RTC sub seconds counter and match values. The RTC value can be read by first reading the HIBRTCC register, reading the RTCSSC field in the HIBRTCSS register, and then rereading the HIBRTCC register. If the two values for HIBRTCC are equal, the read is valid. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Note: There is a minimum system clock rate of three times the HIB clock rate to properly read the HIBRTCSS register. Hibernation RTC Sub Seconds (HIBRTCSS) Base 0x400F.C000 Offset 0x028 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RTCSSM reserved Type Reset 23 RTCSSC Bit/Field Name Type Reset 31 reserved RO 0 30:16 RTCSSM RW 0x0000 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. RTC Sub Seconds Match The match value is contained in this field in one RTCOSC clock increments. A read returns the current seconds match value. 15 reserved RO 0 14:0 RTCSSC RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. RTC Sub Seconds Count This field contains the sub second RTC count and is read as RTCOSC clock units. For the 32.768-kHz clock source, this would be in units of 1/32,768 seconds. June 18, 2014 571 Texas Instruments-Production Data Hibernation Module Register 11: Hibernation IO Configuration (HIBIO), offset 0x02C This register is used to lock and unlock the external wake pin levels and enable the external RST pin and/or GPIO pins, Port K[7:4], as valid external WAKE sources. Note: This register is in the system clock domain and does not require monitoring the WRC bit of the HIBCTL register before issuing a read or write of this register. Writes to this register are immediate. Note: This register is in the core voltage domain and will not retain values over a hibernate cycle Hibernation IO Configuration (HIBIO) Base 0x400F.C000 Offset 0x02C Type RW, reset 0x8000.0000 31 30 29 28 27 26 25 24 22 21 20 19 18 17 16 RO 1 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 IOWRC Type Reset 23 reserved reserved Type Reset RO 0 WURSTEN Bit/Field Name Type Reset 31 IOWRC RO 0x1 RW 0 reserved RO 0 WUUNLK RO 0 RO 0 RW 0 Description I/O Write Complete Indicates whether or not the configuration that was programmed by the WURSTEN bit or GPIOWAKEPEN and GPIOWAKELVL registers have propagated through the pad ring. Value Description 30:5 reserved RO 0x0000.000 4 WURSTEN RW 0 0 The changes programmed in the external pad I/O wake source registers have not propagated through the pad I/O. 1 The changes programmed in the external pad I/O wake source registers have propagated through the pad I/O. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Reset Wake Source Enable This register bit programming takes affect after WUUNLK has been set. Value Description 3:1 reserved RO 0x0 0 The RST signal is not enabled as a wake source. 1 The RST signal is enabled as a wake source. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 572 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 WUUNLK RW 0 Description I/O Wake Pad Configuration Enable Value Description 0 The I/O WAKE configuration set by the WURSTEN bit or in the GPIO module registers GPIOWAKEPEN and GPIOWAKELVL is ignored. 1 Implement the I/O WAKE configuration, level and enables for the external RST pin and/or GPIO wake-enabled pins. Note: This bit must be cleared before issuing a hibernate request by setting the HIBREQ bit in the HIBCTL register. June 18, 2014 573 Texas Instruments-Production Data Hibernation Module Register 12: Hibernation Data (HIBDATA), offset 0x030-0x06F This address space is implemented as a 16x32-bit memory (64 bytes). It can be loaded by the system processor in order to store state information and retains its state during a power cut operation as long as a battery is present. HIBDATA registers 0x050 to 0x064 (upper eight words) may only be accessed using the processor privileged mode (default). Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Note: If VDD is arbitrarily removed while a HIBDATA register write operation is in progress, the write operation must be retried after VDD is reapplied. Hibernation Data (HIBDATA) Base 0x400F.C000 Offset 0x030-0x06F Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RTD Type Reset RTD Type Reset Bit/Field Name Type Reset 31:0 RTD RW - Description Hibernation Module NV Data 574 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 13: Hibernation Calendar Control (HIBCALCTL), offset 0x300 The Hibernate calendar is enabled by setting the CALEN bit in the HIBCALCTL register. If the BCD bit is set, the fields are reported in BCD format. Hibernation Calendar Control (HIBCALCTL) Base 0x400F.C000 Offset 0x300 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 CAL24 reserved CALEN RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RO 0 RW 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset Description 31:3 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 CAL24 RW 0 Calendar Mode Value Description 0 12 hour, AM/PM Mode 1 24 hour mode 1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 CALEN RW 0 RTC Calendar/Counter Mode Select Note that the RTC must be enabled by setting the RTCEN bit in the HIBCTL register to use this mode select. Value Description 0 RTC Counter mode enabled. 1 Calendar mode enabled June 18, 2014 575 Texas Instruments-Production Data Hibernation Module Register 14: Hibernation Calendar 0 (HIBCAL0), offset 0x310 The Hibernation Calendar 0 (HIBCAL0) register is used when the CALEN bit is set in the HIBCALCTL register. Hibernation Calendar 0 (HIBCAL0) Base 0x400F.C000 Offset 0x310 Type RO, reset 0x0000.0000 31 30 29 28 27 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 VALID Type Reset RO 0 25 24 23 RO 0 RO 0 RO 0 RO 0 10 9 8 7 RO 0 RO 0 RO 0 RO 0 reserved reserved Type Reset 26 RO 0 MIN 22 21 20 19 18 AMPM reserved RO 0 RO 0 RO 0 RO 0 Name Type Reset 31 VALID RO 0 16 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 HR reserved Bit/Field 17 SEC Description Valid Calendar Load The calendar may take several cycles to update as the values roll over. This bit indicates whether the HIBCAL0 register contents are valid. Value Description 0 Register currently updating or initializing 1 HIBCAL0 register valid and ready. 30:23 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 22 AMPM RO 0 AM/PM Designation This bit is used when CAL24=0 in the HIBCALCTL register. Value Description 0 AM 1 PM 21 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 20:16 HR RO 0 Hours This field holds the hour information in hexadecimal. For military time, bits 20:16 range from 0x0 to 0x17 (0 to 23 hours). For standard time (AM/PM mode) bits 20:16 range from 0x0 to 0x11, with 0x0 representing 12AM or 12 PM. 15:14 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 576 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 13:8 MIN RO 0 Description Minutes This field holds the minute information in hexadecimal. Bits 13:8 correspond to hex values from 0x0 to 0x3b (0 to 59 minutes). 7:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5:0 SEC RO 0 Seconds This field holds the seconds value in hexadecimal. Bits 5:0 correspond to hex values from 0x0 to 0x3b (0 to 59 seconds). June 18, 2014 577 Texas Instruments-Production Data Hibernation Module Register 15: Hibernation Calendar 1 (HIBCAL1), offset 0x314 The Hibernation Calendar 1 (HIBCAL1) register is used when the CALEN bit is set in the HIBCALCTL register. Hibernation Calendar 1 (HIBCAL1) Base 0x400F.C000 Offset 0x314 Type RO, reset 0x0000.0000 31 30 29 RO 0 RO 0 RO 0 15 14 13 RO 0 RO 0 VALID Type Reset 28 27 26 RO 0 RO 0 RO 0 RO 0 RO 0 12 11 10 9 RO 0 RO 0 RO 0 RO 0 reserved 24 22 21 20 RO 0 RO 0 RO 0 RO 0 8 7 6 5 RO 0 RO 0 RO 0 DOW reserved Type Reset 25 23 MON RO 0 18 17 16 RO 0 RO 0 RO 0 RO 0 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved 19 YEAR reserved Bit/Field Name Type Reset 31 VALID RO 0 RO 0 DOM RO 0 Description Valid Calendar Load The calendar may take several cycles to update as the values roll over. This bit indicates whether the HIBCAL1 register contents are valid. Value Description 0 Register currently updating or initializing 1 HIBCAL1 register valid and ready. 30:27 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 26:24 DOW RO 0 Day of Week This field displays the day of the week in the encodings 0x0 to 0x6. The application defines which days are assigned to each encoding. 23 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 22:16 YEAR RO 0 Year Value The last two digits of the year are stored in hexadecimal in this field. Bits 22:16 correspond to hex values from 0x0 to 0x63 (0 to 99 years). 15:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11:8 MON RO 0 Month This field holds the month value in hexadecimal. Bits 11:8 correspond to hex values from 0x1 to 0xC (1 to 12 months). 7:5 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 578 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4:0 DOM RO 0 Description Day of Month This field holds the day of the month value in hexadecimal. Bits 4:0 correspond to hex values from 0x1 to 1F (1 to 31 days). The value 0 is used to show an ignore match. June 18, 2014 579 Texas Instruments-Production Data Hibernation Module Register 16: Hibernation Calendar Load 0 (HIBCALLD0), offset 0x320 The Hibernation Calendar Load (HIBCALLD0) register is used when the CALEN bit is set in the HIBCALCTL register. Note: This register is write-only; any reads to this register read back as zeros. Errant writes to the HIBCALLD0/1 registers are protected by the Hibernate HIBLOCK register. Hibernation Calendar Load 0 (HIBCALLD0) Base 0x400F.C000 Offset 0x320 Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 reserved Type Reset RO 0 RO 0 WO 0 WO 0 21 reserved 20 19 RO 0 RO 0 RO 0 WO 0 RO 0 WO 0 WO 0 10 9 8 7 6 5 4 3 reserved WO 0 WO 0 WO 0 RO 0 RO 0 18 17 16 WO 0 WO 0 WO 0 2 1 0 WO 0 WO 0 WO 0 HR RO 0 MIN WO 0 22 AMPM SEC WO 0 WO 0 WO 0 Bit/Field Name Type Reset Description 31:23 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 22 AMPM WO 0 AM/PM Designation This bit is used when CAL24=0 in the HIBCALCTL register. Value Description 0 AM 1 PM 21 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 20:16 HR WO 0 Hours This field holds the hour information in hexadecimal. Bits 20:16 correspond to hex values from 0x0 to 0x17 (0 to 23 hours). 15:14 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 13:8 MIN WO 0 Minutes This field holds the minute information in hexadecimal. Bits 13:8 correspond to hex values from 0x0 to 0x3B (0 to 59 minutes). 7:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 580 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 5:0 SEC WO 0 Description Seconds This field holds the seconds value in hexadecimal. Bits 5:0 correspond to hex values from 0x0 to 0x3B (0 to 59 seconds). June 18, 2014 581 Texas Instruments-Production Data Hibernation Module Register 17: Hibernation Calendar Load (HIBCALLD1), offset 0x324 The Hibernation Calendar Load 1 (HIBCALLD1) register is used when the CALEN bit is set in the HIBCALCTL register. Note: This register is write-only; any reads to this register read back as zeros. Errant writes to the HIBCALLD0/1 registers are protected by the Hibernate HIBLOCK register. Hibernation Calendar Load (HIBCALLD1) Base 0x400F.C000 Offset 0x324 Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 WO 0 15 14 13 12 11 10 reserved Type Reset RO 0 RO 0 24 DOW 23 WO 0 WO 0 RO 0 9 8 7 MON RO 0 RO 0 WO 0 WO 0 22 21 20 reserved 19 WO 0 WO 0 WO 0 WO 0 6 5 4 3 reserved WO 0 WO 0 18 17 16 WO 0 WO 0 WO 0 2 1 0 WO 0 WO 0 YEAR RO 0 RO 0 DOM RO 0 WO 0 WO 0 WO 0 Bit/Field Name Type Reset Description 31:27 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 26:24 DOW WO 0 Day of Week This field is written with the day of the week in the encodings 0x0 to 0x6. The application defines which days are assigned to each encoding. 23 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 22:16 YEAR WO 0 Year Value The last two digits of the year are written in this field in hexadecimal. For example, "12" would be programmed into this field for 2012. Bits 22:16 correspond to hex values from 0x0 to 0x63 (0 to 99 years). 15:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11:8 MON WO 0 Month The month value is written in this field in hexadecimal. Bits 11:8 correspond to hex values from 0x1 to 0xC (1 to 12 months). 7:5 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4:0 DOM WO 0 Day of Month The day of the month value is written in this field in hexadecimal. Bits 4:0 correspond to hex values from 0x1 to 1F (1 to 31 days). The encoding 0x0 is reserved for the ignore match function. 582 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 18: Hibernation Calendar Match 0 (HIBCALM0), offset 0x330 The Hibernation Calendar Match 0 (HIBCALM0) register is used when the CALEN bit is set in the HIBCALCTL register. This register is loaded with desired match values for calendar mode. Once the HIBCAL0/1 register values equal the HIBCALM0/1 register values, the RTCALT0 bit is set in the HIBRIS register. Note: The day of week, month and year are not included in the match functionality. Hibernation Calendar Match 0 (HIBCALM0) Base 0x400F.C000 Offset 0x330 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 reserved Type Reset RO 0 RO 0 RW 0 RW 0 21 reserved 20 19 RO 0 RO 0 RO 0 RW 0 RO 0 RW 0 RW 0 10 9 8 7 6 5 4 3 reserved RW 0 RW 0 RW 0 RO 0 RO 0 18 17 16 RW 0 RW 0 RW 0 2 1 0 RW 0 RW 0 RW 0 HR RO 0 MIN RW 0 22 AMPM SEC RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:23 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 22 AMPM RW 0 AM/PM Designation This bit is used when CAL24=0 in the HIBCALCTL register. Value Description 0 AM 1 PM 21 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 20:16 HR RW 0 Hours This field match value for the hours in hexadecimal units. Bits 20:16 correspond to hex values from 0x0 to 0x17 (0 to 23 hours). To ignore the hours match, write this field to all 1s. 15:14 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 13:8 MIN RW 0 Minutes This field holds the match value for minutes in hexadecimal units. Bits 13:8 correspond to hex values from 0x0 to 0x3B (0 to 59 minutes). To ignore the hours match, write this field to all 1s. 7:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 583 Texas Instruments-Production Data Hibernation Module Bit/Field Name Type Reset 5:0 SEC RW 0 Description Seconds This field holds the match value for seconds. The value is represented in hexadecimal. Bits 5:0 correspond to hex values from 0x0 to 0x3b (0 to 59 seconds). To ignore the hours match, write this field to all 1s. 584 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: Hibernation Calendar Match 1 (HIBCALM1), offset 0x334 The Hibernation Calendar Match 1 (HIBCALM1) register is used when the CALEN bit is set in the HIBCALCTL register. This register is loaded with desired match values for calendar mode. Once the HIBCAL0/1 register values equal the HIBCALM0/1 register values, the RTCALT0 bit is set in the HIBRIS register. Note: The day of week, month and year are not included in the match functionality. Hibernation Calendar Match 1 (HIBCALM1) Base 0x400F.C000 Offset 0x334 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 2 1 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 10 9 8 7 6 5 4 3 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 DOM RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:5 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4:0 DOM RW 0 Day of Month This field holds the match value for the day of the month in hexadecimal. Bits 4:0 correspond to hex values from 0x1 to 1F (1 to 31 days). To disable match for the day of the month, the value 0x0 is used. June 18, 2014 585 Texas Instruments-Production Data Hibernation Module Register 20: Hibernation Lock (HIBLOCK), offset 0x360 Writing 0xA335.9554 to the HIBLOCK register enables write access to the HIBRTCLD, HIBCALLD0, HIBCALLD1 and Tamper registers. Writing any other value to the HIBLOCK register re-enables the locked state for register writes to all the other registers. Reading the HIBLOCK register returns the lock status rather than the 32-bit value written. Therefore, when write accesses are disabled, reading the HIBLOCK register returns 0x0000.0001 when locked; otherwise, the returned value is 0x0000.0000 (unlocked). Hibernation Lock (HIBLOCK) Base 0x400F.C000 Offset 0x360 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 HIBLOCK Type Reset HIBLOCK Type Reset Bit/Field Name Type Reset 31:0 HIBLOCK RW 0x0000 RW 0 Description HIbernate Lock A write of 0xA335.9554 unlocks the HIBRCTL and Tamper registers. 586 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 21: HIB Tamper Control (HIBTPCTL), offset 0x400 The Tamper Control (HIBTPCTL) register provides control of the module. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Note: Errant writes to the Tamper registers are protected by the Hibernate HIBLOCK register. HIB Tamper Control (HIBTPCTL) Base 0x400F.C000 Offset 0x400 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 11 10 WAKE reserved RW 0 RO 0 MEMCLR RW 0 reserved RW 0 RO 0 RO 0 TPCLR RO 0 W1C 0 reserved RO 0 RO 0 0 TPEN RO 0 RW 0 Bit/Field Name Type Reset Description 31:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 WAKE RW 0 Wake from Hibernate on a Tamper Event Value Description 0 Do not wake from hibernate on a tamper event. 1 Wake from hibernate on a tamper event. 10 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 9:8 MEMCLR RW 0 HIB Memory Clear on Tamper Event Value Description 0x0 Do not Clear HIB memory on tamper event. 0x1 Clear Lower 32 Bytes of HIB memory on tamper event 0x2 Clear upper 32 Bytes of HIB memory on tamper event 0x3 Clear all HIB memory on tamper event June 18, 2014 587 Texas Instruments-Production Data Hibernation Module Bit/Field Name Type Reset Description 7:5 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 TPCLR W1C 0 Tamper Event Clear Writing a 1 to this bit clears the tamper event. The status of the clear is reflected in the STATE bit field. 3:1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 TPEN RW 0 Tamper Module Enable This bit enables the Tamper module. Value Description 0 Tamper module disabled. 1 Tamper module Enabled. Note: Once tamper is enabled, the following HIBCTL register bits are locked and cannot be modified: ■ OSCSEL ■ OSCDRV ■ OSCBYP ■ VDD3ON ■ CLK32EN ■ RTCEN 588 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 22: HIB Tamper Status (HIBTPSTAT), offset 0x404 The HIB Tamper Status (HIBTPCTL) register provides status of the module. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Note: Errant writes to the Tamper registers are protected by the Hibernate HIBLOCK register. HIB Tamper Status (HIBTPSTAT) Base 0x400F.C000 Offset 0x404 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 2 STATE RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 XOSCST XOSCFAIL RO 0 RO 0 RW1C 0 Bit/Field Name Type Reset Description 31:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3:2 STATE RO 0 Tamper Module Status Tamper is defined as being configured when the tamper I/Os have been enabled (setting the ENx bits in the HIBTPIO register). Value Description 1 XOSCST RO 0 0x0 Tamper disabled. 0x1 Tamper configured. 0x2 Tamper pin event occurred. External Oscillator Status Value Description 0 Active 1 Stopped June 18, 2014 589 Texas Instruments-Production Data Hibernation Module Bit/Field Name Type Reset 0 XOSCFAIL RW1C 0 Description External Oscillator Failure Write a 1 to this bit to clear it. Value Description 0 External oscillator is valid. 1 External oscillator has failed 590 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 23: HIB Tamper I/O Control (HIBTPIO), offset 0x410 The HIB Tamper I/O Control (HIBTPIO) register provides control of the Tamper I/O. Note: Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module registers are on the Hibernation module clock domain and have special timing requirements. Software should make use of the WRC bit in the HIBCTL register to ensure that the required timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See “Register Access Timing” on page 535. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register do not require waiting for write to complete. Because these registers are clocked by the system clock, writes to these registers/bits are immediate. Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL register has been set may produce unexpected results. Note: Errant writes to the Tamper registers are protected by the Hibernate HIBLOCK register. HIB Tamper I/O Control (HIBTPIO) Base 0x400F.C000 Offset 0x410 Type RW, reset 0x0000.0000 31 30 29 28 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 27 26 25 24 GFLTR3 PUEN3 LEV3 EN3 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 11 10 9 8 GFLTR1 PUEN1 LEV1 EN1 RW 0 RW 0 RW 0 RW 0 23 22 21 20 reserved reserved RO 0 RO 0 RO 0 RO 0 19 18 17 16 GFLTR2 PUEN2 LEV2 EN2 RW 0 RW 0 RW 0 RW 0 3 2 1 0 GFLTR0 PUEN0 LEV0 EN0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:28 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 27 GFLTR3 RW 0 TMPR3 Glitch Filtering Value Description 26 PUEN3 RW 0 0 A trigger match level is ignored until the TMPR3 signal is stable for two hibernate clocks. 1 A trigger match level is ignored until the TMPR3 signal is stable for 3,071 Hibernate Clocks (93.7ms using 32.768 kHz). TMPR3 Internal Weak Pull-up Enable Value Description 0 Pull-up disabled 1 Pull-up enabled June 18, 2014 591 Texas Instruments-Production Data Hibernation Module Bit/Field Name Type Reset 25 LEV3 RW 0 Description TMPR3 Trigger Level Value Description 24 EN3 RW 0 0 Trigger on level low 1 Trigger on level high TMPR3 Enable Value Description 0 Detect disabled 1 Detect enabled 23:20 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 GFLTR2 RW 0 TMPR2 Glitch Filtering Value Description 18 PUEN2 RW 0 0 A trigger match level is ignored until the TMPR2 signal is stable for two hibernate clocks. 1 A trigger match level is ignored until the TMPR2 signal is stable for 3,071 Hibernate Clocks (93.7ms using 32.768 kHz). TMPR2 Internal Weak Pull-up Enable Value Description 17 LEV2 RW 0 0 Pull-up disabled 1 Pull-up enabled TMPR2 Trigger Level Value Description 16 EN2 RW 0 0 Trigger on level low 1 Trigger on level high TMPR2 Enable Value Description 15:12 reserved RO 0 0 Detect disabled 1 Detect enabled Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 592 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 11 GFLTR1 RW 0 Description TMPR1 Glitch Filtering Value Description 10 PUEN1 RW 0 0 A trigger match level is ignored until the TMPR1 signal is stable for two hibernate clocks. 1 A trigger match level is ignored until the TMPR1 signal is stable for 3,071 Hibernate Clocks (93.7ms using 32.768 kHz). TMPR1 Internal Weak Pull-up Enable Value Description 9 LEV1 RW 0 0 Pull-up disabled 1 Pull-up enabled TMPR1 Trigger Level Value Description 8 EN1 RW 0 0 Trigger on level low 1 Trigger on level high TMPR1Enable Value Description 0 Detect disabled 1 Detect enabled 7:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 GFLTR0 RW 0 TMPR0 Glitch Filtering Value Description 2 PUEN0 RW 0 0 A trigger match level is ignored until the TMPR0 signal is stable for two hibernate clocks. 1 A trigger match level is ignored until the TMPR0 signal is stable for 3,071 Hibernate Clocks (93.7ms using 32.768 kHz). TMPR0 Internal Weak Pull-up Enable Value Description 0 Pull-up disabled 1 Pull-up enabled June 18, 2014 593 Texas Instruments-Production Data Hibernation Module Bit/Field Name Type Reset 1 LEV0 RW 0 Description TMPR0 Trigger Level Value Description 0 EN0 RW 0 0 Trigger on level low 1 Trigger on level high TMPR0 Enable Value Description 0 Detect disabled 1 Detect enabled 594 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 24: HIB Tamper Log 0 (HIBTPLOG0), offset 0x4E0 Register 25: HIB Tamper Log 2 (HIBTPLOG2), offset 0x4E8 Register 26: HIB Tamper Log 4 (HIBTPLOG4), offset 0x4F0 Register 27: HIB Tamper Log 6 (HIBTPLOG6), offset 0x4F8 The HIB Tamper Log (HIBTPLOG) even registers capture the time information during a tamper event. Up to four tamper logs can be stored. The HIBTPLOG registers are cleared when the TPCLR bit is written in the HIBTPCTL register. Note: It is recommended that an external oscillator is used if accurate time stamps on the tamper log are critical. HIB Tamper Log 0 (HIBTPLOG0) Base 0x400F.C000 Offset 0x4E0 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 TIME Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 TIME Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:0 TIME RO 0x0 RO 0 Description Tamper Log Calendar Information. When the hibernate module is configured for RTC count mode, the time from the RTCCC register is captured on a tamper event. If the calendar function is enabled, the captured time is configured as the hex values for year, month, day, hour, minute and seconds. 24 hour mode should be used by setting the CAL24 bit in HIBCALCTL register. The format of the calendar information is as follows: ■ TIME[31:26]: Year (0-64) ■ TIME[25:22]: Month ■ TIME[21:17]: Day of month ■ TIME[16:12]: Hours ■ TIME[11:6]: Minutes ■ TIME[5:0]: Seconds June 18, 2014 595 Texas Instruments-Production Data Hibernation Module Register 28: HIB Tamper Log 1 (HIBTPLOG1), offset 0x4E4 Register 29: HIB Tamper Log 3 (HIBTPLOG3), offset 0x4EC Register 30: HIB Tamper Log 5 (HIBTPLOG5), offset 0x4F4 Register 31: HIB Tamper Log 7 (HIBTPLOG7), offset 0x4FC The HIB Tamper Log (HIBTPLOGn) odd registers capture the trigger information during a tamper event. Up to four tamper logs can be stored. The HIBTPLOG registers are cleared when the TPCLR bit is set to 1 in the HIBTPCTL register. The HIBTPLOG7 register contains to OR of all events after the 3rd event is logged in HIBTPLOG5. The HIBTPLOG7 register is cleared on a Hibernation module reset. HIB Tamper Log 1 (HIBTPLOG1) Base 0x400F.C000 Offset 0x4E4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 24 23 22 21 20 19 18 17 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 5 4 3 2 1 0 TRIG3 TRIG2 TRIG1 TRIG0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset XOSC reserved Type Reset 16 Bit/Field Name Type Reset Description 31:17 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 16 XOSC RO 0 Status of external 32.768-kHz oscillator Value Description 0 Default 1 32.768-kHz oscillator has failed 15:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 TRIG3 RO 0 Status of TMPR[3] Trigger Value Description 2 TRIG2 RO 0 0 Default 1 A tamper event has been detected on TMPR[3] Status of TMPR[2] Trigger Value Description 0 Default 1 A tamper event has been detected on TMPR[2] 596 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1 TRIG1 RO 0 Description Status of TMPR[1] Trigger Value Description 0 TRIG0 RO 0 0 Default 1 A tamper event has been detected on TMPR[1] Status of TMPR[0] Trigger Value Description 0 Default 1 A tamper event has been detected on TMPR[0] June 18, 2014 597 Texas Instruments-Production Data Hibernation Module Register 32: Hibernation Peripheral Properties (HIBPP) , offset 0xFC0 This register describes the features available within the Hibernation Module. Hibernation Peripheral Properties (HIBPP) Base 0x400F.C000 Offset 0xFC0 Type RO, reset 0x0000.0002 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset TAMPER WAKENC RO 1 RO 0 Bit/Field Name Type Reset Description 31:2 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1 TAMPER RO 0x1 Tamper Pin Presence Value Description 0 WAKENC RO 0x0 0 Tamper module is not present. 1 Tamper module is present. Wake Pin Presence Value Description 0 WAKE pin is present. 1 WAKE pin is not part of the package pinout. 598 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 33: Hibernation Clock Control (HIBCC), offset 0xFC8 This register enables alternate clock sources. Note: This register is in the system clock domain. Writes to this register do not require waiting for the WRC bit of the HIBCTL register to be set. Hibernation Clock Control (HIBCC) Base 0x400F.C000 Offset 0xFC8 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:1 reserved RO 0x0000 0 SYSCLKEN RW 0x0 RO 0 0 SYSCLKEN RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. RTCOSC to System Clock Enable This bit RTCOSC clock to be sent to the system control for selection as a possible system clock source. Default mode is disabled to support low power modes. Value Description 0 RTCOSC is not available as a system clock source. 1 RTCOSC is available for use as a system clock source. June 18, 2014 599 Texas Instruments-Production Data Internal Memory 8 Internal Memory The TM4C1294NCPDT microcontroller comes with 256 KB of bit-banded SRAM, internal ROM, 1024 KB of Flash memory, and 6KB of EEPROM. The TM4C1294NCPDT microcontroller provides 1024 KB of on-chip Flash memory. The Flash memory is configured as four banks of 16K x 128 bits (4 * 256 KB total) which are two-way interleaved. Memory blocks can be marked as read-only or execute-only, providing different levels of code protection. Read-only blocks cannot be erased or programmed, protecting the contents of those blocks from being modified. Execute-only blocks cannot be erased or programmed, and can only be read by the controller instruction fetch mechanism, protecting the contents of those blocks from being read by either the controller or by a debugger. The TM4C1294NCPDT microcontroller provides enhanced performance and power savings by implementation of two sets of instruction prefetch buffers. Each prefetch buffer is 2 x 256 bits and can be combined as a 4 x 256-bit prefetch buffer. The EEPROM module provides a well-defined register interface to support accesses to the EEPROM with both a random access style of read and write as well as a rolling or sequential access scheme. A password model allows the application to lock one or more EEPROM blocks to control access on 16-word boundaries. 8.1 Block Diagram Figure 8-1 on page 601 illustrates the internal memory and control structure . The dashed box in the figure indicate registers residing in the System Control module. 600 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 8-1. Internal Memory Block Diagram EEPROM Control EESIZE EEBLOCK EEOFFSET EERDWR EEDWRINC EEPROM Array EEDONE EESUPP EEUNLOCK EEPROT EEPASSn EEINT EEHIDE EEDBGME EEPROMPP SPB ROMSWMAP Flash Control FMA FMD ICODE FMC FCRIS FCIM DCODE FCMISC FSIZE CORTEX M4 FLASHPP FLASHCONF FLPEKEY SPB Bus Matrix DMA DMA Control FLASHDMASZ FLASHDMAST ROM 2x256-bit Prefetch Buffer 0 2x256-bit Prefetch Buffer 1 Flash Write Buffer Control FMC2 FWBVAL 8-KB Sectors 8-KB Sectors 8-KB Sectors 8-KB Sectors SRAM Control SSIZE Flash Protection FMPPEn FMPREn FWBn (32 word write buffers) User Registers BOOTCFG SRAM (four-way interleaved banks) USER_REGn USRPWRUP Flash Array (2-Way Interleaved) Boot Registers SCV RVP To Peripherals June 18, 2014 601 Texas Instruments-Production Data Internal Memory 8.2 Functional Description This section describes the functionality of the SRAM, ROM, Flash, and EEPROM memories. Note: 8.2.1 The μDMA has read-only access to flash (in Run Mode only). SRAM The internal system SRAM of the Tiva™ C Series devices is located at address 0x2000.0000 of the device memory map. To reduce the number of time consuming read-modify-write (RMW) operations, ARM provides bit-banding technology in the processor. With a bit-band-enabled processor, certain regions in the memory map (SRAM and peripheral space) can use address aliases to access individual bits in a single, atomic operation. The bit-band base is located at address 0x2200.0000. The bit-band alias is calculated by using the formula: bit-band alias = bit-band base + (byte offset * 32) + (bit number * 4) For example, if bit 3 at address 0x2000.1000 is to be modified, the bit-band alias is calculated as: 0x2200.0000 + (0x1000 * 32) + (3 * 4) = 0x2202.000C With the alias address calculated, an instruction performing a read/write to address 0x2202.000C allows direct access to only bit 3 of the byte at address 0x2000.1000. For details about bit-banding, see “Bit-Banding” on page 109. Note: The SRAM is implemented using four-way 32-bit wide interleaved SRAM banks (separate SRAM arrays) which allow for increased speed between memory accesses. When using interleaving, a write to one bank followed by a read of another bank can occur in successive clock cycles without incurring any delay. However, a write access that is followed immediately by a read access to the same bank incurs a stall of a single clock cycle. The SRAM memory layout allows for multiple masters to access different SRAM banks simultaneously. If two masters attempt to access the same SRAM bank, the master with the higher priority gains access to the memory bus and the master with the lower priority is stalled by one wait state. If four masters attempt to access the same SRAM bank, access by the master with the lowest priority is delayed by three wait states. The CPU core always has the highest priority for SRAM memory accesses. 8.2.2 ROM The internal ROM of the Tiva™ C Series device is located at address 0x0100.0000 of the device memory map. Detailed information on the ROM contents can be found in the Tiva™ C Series TM4C129x ROM User’s Guide (literature number SPMU363). The ROM contains the following components: ■ TivaWare™ Boot Loader and vector table ■ TivaWare Peripheral Driver Library (DriverLib) release for product-specific peripherals and interfaces ■ Advanced Encryption Standard (AES) cryptography tables ■ Cyclic Redundancy Check (CRC) error detection functionality The boot loader is used as an initial program loader (when the Flash location 0x0000.0004, the reset vector location is all 1s (that is, erased state of Flash)) as well as an application-initiated 602 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller firmware upgrade mechanism (by calling back to the boot loader). The Peripheral Driver Library APIs in ROM can be called by applications, reducing Flash memory requirements and freeing the Flash memory to be used for other purposes (such as additional features in the application). Advanced Encryption Standard (AES) is a publicly defined encryption standard used by the U.S. Government. Cyclic Redundancy Check (CRC) is a technique to validate whether a block of data has the same contents as when previously checked. Note: 8.2.2.1 CRC software program are available in TivaWare for backward-compatibility. A device that has enhanced CRC integrated module should utilize this hardware for best performance. Please refer to “Cyclical Redundancy Check (CRC)” on page 946 for more information. Boot Configuration After Power-On-Reset (POR) and device initialization occurs, the hardware loads the stack pointer from either flash or ROM based on the presence of an application in flash and the state of the EN bit in the BOOTCFG register. If the flash address 0x0000.0004 contains an erased word (value 0xFFFF.FFFF) or the EN bit is of the BOOTCFG register is clear, the stack pointer and reset vector pointer are loaded from ROM at address 0x0100.0000 and 0x0100.0004, respectively. The boot loader executes and configures the available boot slave interfaces and waits for an external memory to load its software. The boot loader uses a simple packet interface to provide synchronous communication with the device. The speed of the boot loader is determined by the internal oscillator (PIOSC) frequency. The following serial interfaces can be used: ■ ■ ■ ■ UART0 SSI0 I2C0 USB If the check of the Flash at address 0x0000.0004 contains a valid reset vector value and the EN bit in the BOOTCFG register is set, the stack pointer and reset vector values are fetched from the beginning of flash. This application stack pointer and reset vector are loaded and the processor executes the application directly. Otherwise, the stack pointer and reset vector values are fetched from the beginning of ROM. 8.2.2.2 TivaWare Peripheral Driver Library The TivaWare Peripheral Driver Library contains a file called driverlib/rom.h that assists with calling the peripheral driver library functions in the ROM. The detailed description of each function is available in the Tiva™ C Series TM4C129x ROM User’s Guide (literature number SPMU363). See the "Using the ROM" chapter of the TivaWare™ Peripheral Driver Library for C Series User's Guide (literature number SPMU298) for more details on calling the ROM functions and using driverlib/rom.h. A table at the beginning of the ROM points to the entry points for the APIs that are provided in the ROM. Accessing the API through these tables provides scalability; while the API locations may change in future versions of the ROM, the API tables do not. The tables are split into two levels; the main table contains one pointer per peripheral which points to a secondary table that contains one pointer per API that is associated with that peripheral. The main table is located at 0x0100.0010, right after the Cortex-M4F vector table in the ROM. DriverLib functions are described in detail in the TivaWare™ Peripheral Driver Library for C Series User's Guide (literature number SPMU298). Additional APIs are available for graphics and USB functions, but are not preloaded into ROM. The TivaWare Graphics Library provides a set of graphics primitives and a widget set for creating graphical user interfaces on Tiva™ C Series microcontroller-based boards that have a graphical display (for June 18, 2014 603 Texas Instruments-Production Data Internal Memory more information, see the TivaWare™ Graphics Library for C Series User's Guide (literature number SPMU300)). The TivaWare USB Library is a set of data types and functions for creating USB Device, Host or On-The-Go (OTG) applications on Tiva™ C Series microcontroller-based boards (for more information, see the TivaWare™ USB Library for C Series User's Guide (literature number SPMU297)). 8.2.2.3 Advanced Encryption Standard (AES) Cryptography Tables AES is a strong encryption method with reasonable performance and size. AES is fast in both hardware and software, is fairly easy to implement, and requires little memory. AES is ideal for applications that can use prearranged keys, such as setup during manufacturing or configuration. Four data tables used by the XySSL AES implementation are provided in the ROM. The first is the forward S-box substitution table, the second is the reverse S-box substitution table, the third is the forward polynomial table, and the final is the reverse polynomial table. See the Tiva™ C Series TM4C129x ROM User’s Guide (literature number SPMU363) for more information on AES. 8.2.2.4 Cyclic Redundancy Check (CRC) Error Detection The CRC technique can be used to validate correct receipt of messages (nothing lost or modified in transit), to validate data after decompression, to validate that Flash memory contents have not been changed, and for other cases where the data needs to be validated. A CRC is preferred over a simple checksum (for example, XOR all bits) because it catches changes more readily. When device initialization is executing from ROM, a CRC-32 validates the data being transferred into registers and memory. The CRC ensures no instructions were skipped in a sequence or no data was corrupted during transfer. See the Tiva™ C Series TM4C129x ROM User’s Guide (literature number SPMU363) for more information on CRC. 8.2.3 Flash Memory The Flash memory is configured in groups of four banks four banks of 16K x 128 bits (4 * 256 KB total) which are two-way interleaved as shown below. 604 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 8-2. Flash Memory Configuration 0x0F.FFFC 0x0F.FFF8 0x0F.FFF4 0x0F.FFF0 0x0F.FFEC 8 KB Sector31-1 Bank 3 0x0F.FFE8 0x0F.FFE4 0x0F.FFE0 8 KB Sector31-1 Bank 2 512 KB High Region 0x08.401C 0x08.4018 0x08.4014 0x08.4010 0x08.400C 0x08.4008 0x08.4004 0x08.4000 0x08.3FFC 0x08.3FF8 0x08.3FF4 0x08.3FF0 0x08.3FEC 0x08.3FE8 0x08.3FE4 0x08.3FE0 0x08.001C 0x08.0018 0x08.0010 0x08.000C 0x08.0008 8 KB Sector 0 Bank 3 0x08.0014 8 KB Sector 0 Bank 2 256 KB Bank 3: 128-bit output 0x07.FFFC 0x07.FFF8 0x07.FFF4 16 KB 0x08.0004 0x08.0000 256 KB Bank 2: 128-bit output 0x07.FFF0 0x07.FFEC 8 KB Sector31-1 Bank 1 0x07.FFE8 0x07.FFE4 1 MB Flash 0x07.FFE0 8 KB Sector31-1 Bank 0 512 KB Low Region 0x00.401C 0x00.4018 0x00.4014 0x00.4010 0x00.400C 0x00.4008 0x00.4004 0x00.4000 0x00.3FFC 0x00.3FF8 0x00.3FF4 0x00.3FF0 0x00.3FEC 0x00.3FE8 0x00.3FE4 0x00.3FE0 0x00.001C 0x00.0018 0x00.0010 0x00.000C 0x00.0008 8 KB Sector 0 Bank 1 0x00.0014 8 KB Sector 0 Bank 0 256 KB Bank 1: 128-bit output 16 KB 0x00.0004 0x00.0000 256 KB Bank 0: 128-bit output The interleaved memory prefetchs 256 bits at a time. The prefetch buffers allow the maximum performance of a 120 MHz CPU speed to be maintained with linear code or loops that fit within the prefetch buffer. It is recommended that code be compiled with switches set to eliminate "literals" as much as possible as a literal causes a flash access for that word and a stall for the wait states. Most compilers support transforming literals into "in-line" code, which executes faster in a system where the memory subsystem is slower than the CPU. Because the memory is two-way interleaved and each bank individually is an 8-KB sector, when the user erases a sector, using the ERASE bits in the Flash Memory Control (FMC) register, it is a 16 KB erase. Erasing a block causes the entire contents of the block to be reset to all 1s. 8.2.3.1 Flash Configuration Depending on the CPU frequency, the application must program the Flash clock high time (FBCHT), Flash Bank Clock Edge (FBCE) and Flash wait states (FWS) in the Memory Timing Parameter Register 0 for Main Flash and EEPROM (MEMTIM0), System Control Module offset 0x0C0. The following table details the bit field values that are required for the given CPU frequency ranges. Table 8-1. MEMTIM0 Register Configuration versus Frequency CPU Frequency range (f) Time Period Range (t) in ns in MHz Flash Bank Clock High Time (FBCHT) Flash Bank Clock Edge (FBCE) Flash Wait States (FWS) 62.5 0x0 1 0x0 16 < f ≤ 40 62.5 > t ≥ 25 0x2 0 0x1 40 < f ≤60 25 > t ≥ 16.67 0x3 0 0x2 60< f ≤80 16.67 > t ≥ 12.5 0x4 0 0x3 80 < f ≤100 12.5 > t ≥ 10 0x5 0 0x4 16 June 18, 2014 605 Texas Instruments-Production Data Internal Memory Table 8-1. MEMTIM0 Register Configuration versus Frequency (continued) CPU Frequency range (f) Time Period Range (t) in ns in MHz 100< f ≤120 Flash Bank Clock High Time (FBCHT) Flash Bank Clock Edge (FBCE) Flash Wait States (FWS) 0x6 0 0x5 10 > t ≥ 8.33 To update the MEMTIM0 register with the new Flash configuration values, the MEMTIMU bit should be set in the Run and Sleep Mode Configuration Register (RSCLKCFG), System Control offset 0x0B0. Note: 8.2.3.2 The associated Flash and EEPROM fields in the MEMTIM0 register must be programmed to the same values. For example, the FWS field must be programmed to the same value as the EWS field. Prefetch Buffers The prefetch buffers can exist as a single set of 2x256-bit buffers or 4x256-bit buffers depending on the SPFE bit programmed in the Flash Configuration Register (FLASHCONF) register, offset 0xFC8. At reset, all four buffers are enabled. The buffers are filled using a "least-recently-used" (LRU) method. When operating in a single set buffer configuration, the two, 256-bit buffers create a deterministic configuration as each "next" write is sent to the previous buffer that was written. Figure 8-3 on page 606 depicts the single 256-bit buffer set. The single prefetch buffer set should only be used when the code execution must be purely deterministic for the number of clock cycles it takes to execute. Utilizing the four prefetch buffer configuration is the preferred method of configuration. Figure 8-3. Single 256-Bit Prefetch Buffer Set 255 Prefetch Buffer 0 Prefetch Buffer 1 224 223 192 191 160 159 128 127 96 95 64 63 0 32 31 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 When the buffers are configured as four, 256-bit buffers, they function as one set, with one of the four buffers tagged as the LRU and the next to be used when an auto-fill or miss occurs. Figure 8-4. Four 256-Bit Prefetch Buffer Configuration 255 Prefetch Buffer 0 Prefetch Buffer 1 Prefetch Buffer 2 Prefetch Buffer 3 224 223 192 191 160 159 128 127 96 95 64 63 0 32 31 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 The address of the auto-fill is stored in this tag register so that address violations can be identified immediately and miss processing can begin directly. Every ICODE access is checked against valid tags to see if the target word is already in the buffers. If there is a hit, the target word is immediately sent to the CPU with no wait states. If there is a miss, then the prefetch buffer is invalidated and the miss is processed as a 256-bit read from the flash 606 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller subsystem to fill the next, least-recently used prefetch buffer. Two memory banks are read in parallel to retrieve 256-bits worth of data. If an auto-fill has been started and a miss occurs, the auto-fill completes before the miss is processed. If an auto-fill occurs that hits the prefetch buffer being processed for the auto-fill, then the ICODE bus is stalled until the auto fill is complete and new entry can be accessed. For an instruction miss, access to the flash bank starts immediately after the address is available provided the flash sub-system is not already processing a DCODE bus access or a PROGRAM/ERASE operation in the same banks. The target word is passed to the CPU one cycle after it is written to the prefetch buffer. Figure 8-5 on page 607 shows the timing diagram for a hit in the prefetch buffer. Figure 8-5. Single Cycle Access, 0 Wait States CPU Clock A0 ADDRESS A1 Flash Clk Data 0 Data Data 1 The Flash memory can operate at the CPU clock speed with zero-wait-state accesses when data is resident in the prefetch buffers. When an access does not hit in the prefetch buffer, there is a delay that is incurred while the data is transferred from the Flash. This delay is dependent on the programmed CPU frequency. Refer to Table 8-1 on page 605 for required CPU frequency versus programmed wait-state delay information. Figure 8-6 on page 608 depicts the events that occur as the CPU steps through the words in the prefetch buffer that has just been loaded until it reaches the end of the current prefetch line. The notable events are as follows (refer to Figure 8-6 on page 608): ■ EVENT A: When the CPU has a miss in the prefetch buffer, a line is fetched from Flash. The target word is written to the prefetch buffer and sent to the CPU one cycle after. ■ EVENT B: When the CPU reaches Word 3, the next 256-bit buffer line is fetched, resulting in a zero-wait-state access of next line's Word 0 ■ EVENT C: After this word, if the CPU is still executing sequentially, Word 0 of the next buffer line that was fetched is sent to the CPU, with zero-wait-state delay ■ EVENT D: Word 0 from the second fetch that occurred is sent to the CPU June 18, 2014 607 Texas Instruments-Production Data Internal Memory Figure 8-6. Prefetch Fills from Flash 255 Least Recently Used Buffer Prefetch Buffer 0 Prefetch Buffer 1 Prefetch Buffer 2 Prefetch Buffer 3 224 223 192 191 160 159 128 127 96 95 64 63 32 31 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 TAG WORD 7 WORD 6 WORD 5 WORD 4 WORD 3 WORD 2 WORD 1 WORD 0 1 2 3 5 6 WAIT STATES EVENT C 4 EVENT D 7 EVENT B EVENT A Note that if the CPU target word is beyond Word 2 (Word 3 through Word 7) then the next prefetch fill begins immediately and, depending on the CPU frequency, a delay is incurred between CPU access of Word 7 and Word 0 of the next line. Note: For optimal prefetch buffer performance, align application code/branches on 8-word boundaries. Note: Because the prefetch buffers and Flash memory can effectively be utilized at 20 Mhz and above, an application may see an improvement in current consumption from 16 MHz to 20 MHz. The prefetch buffers can be forced ON and OFF by setting the FPFON and FPFOFF bits in the Flash Configuration (FLASHCONF) register at 0xFC8. If the application sets the FPFON or FPFOFF bit while the CPU is currently reading or writing to Flash, the prefetch buffer action of turning on or off happens only after the Flash operation has completed. This feature can be used in test modes when determining optimum memory configuration for code. Prefetch buffer valid tags can be cleared in the following ways: ■ Any Flash Configuration (FLASHCONF) register changes, such as: – Disabling the prefetch buffer by setting the FPFOFF bit – Setting the CLRTV bit to clear the prefetch buffer tags ■ A system reset ■ ROM accesses ■ Error during ICODE accesses ■ System aborts ■ Mirror mode changes Note: 8.2.3.3 If the prefetch buffers are enabled and application code branches to a location other than flash memory which then modifies the flash memory, the prefetch tags must be cleared before returning to flash code execution. Prefetch buffer valid tags can be cleared by setting the CLRTV bit in the FLASHCONF register. Flash Mirror Mode Flash mirroring allows multiple copies of software to exist in Flash simultaneously. The software can run from the lower banks at the same time software is updating a mirrored copy on the upper bank. In addition to the data, the boot loader in both the lower and upper banks must be mirrored 608 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller while programming the flash contents. If data needs to be recovered, a hot swap can be done by setting the FMME bit in the FLASHCONF register to ensure the flash banks are idle during the swap. The prefetch buffers must be invalidated during the execution of a hot swap. Next, the address translation logic decodes up to 512 KB from the upper banks to the lower banks. Once the banks are swapped, the mirrored flash image is then used. The address translation logic translates the address to the upper banks until the next swap. Figure 8-7 on page 609 depicts the configuration necessary when executing Flash mirroring. Note: After a mirror mode has been executed and the code locations have been swapped from the upper memory banks to the lower, the application can continue to read from the lower memory bank address locations. However, when erasing or programming the swapped memory, the application must use the "real" upper memory address of the code before it was swapped. For example, in Figure 8-7 on page 609, when the yellow highlighted location 0x00.3FE8 is swapped with 0x08.3FE8 the application's next read location is 0x00.3FEC. However, if the application were to program or erase the next location it would need to write or erase location 0x08.3FEC Figure 8-7. Mirror Mode Function 0x0F.FFFC 0x0F.FFF8 0x0F.FFF4 0x0F.FFF0 0x0F.FFEC 8 KB Sector31-1 Bank 3 Boot Loader Code should be mirrored in both 512 KB Blocks 0x0F.FFE4 0x0F.FFE0 8 KB Sector31-1 Bank 2 0x08.401C 0x08.4018 0x08.4014 0x08.4010 0x08.400C 0x08.4008 0x08.4004 0x08.4000 0x08.3FFC 0x08.3FF8 0x08.3FF4 0x08.3FF0 0x08.3FEC 0x08.3FE8 0x08.3FE4 0x08.3FE0 8 KB Sector 0 Bank 3 8 KB Sector 0 Bank 2 0x08.001C 0x08.0018 0x08.0014 0x08.0010 0x08.000C 0x08.0008 0x08.0004 0x08.0000 0x07.FFFC 0x07.FFF8 0x07.FFF4 0x07.FFF0 0x07.FFEC 0x07.FFE8 0x07.FFE4 0x07.FFE0 8 KB Sector31-1 Bank 1 Boot Loader Code should be mirrored in both 512 KB Blocks 0x0F.FFE8 8 KB Sector31-1 Bank 0 0x00.401C 0x00.4018 0x00.4014 0x00.4010 0x00.400C 0x00.4008 0x00.4004 0x00.4000 0x00.3FFC 0x00.3FF8 0x00.3FF4 0x00.3FF0 0x00.3FEC 0x00.3FE8 0x00.3FE4 0x00.3FE0 0x00.001C 0x00.0018 0x00.0010 0x00.000C 0x00.0008 8 KB Sector 0 Bank 1 0x00.0014 Upper 512 KB Memory Region This region contains the mirrored application code. Patches and updates can be done in this upper 512 KB of memory in the background while the lower 512 KB is being executed. It is important to ensure that code offsets remain the same as the lower 512 KB memory region so the memory swap is seamless. This entire region is swapped when the FMME bit is set in the FLASHCONF register. When the FMME bit is set the upper 512 KB memory region is swapped with the lower 512 KB region Lower 512 KB Memory Region This region contains the application code being executed. 8 KB Sector 0 Bank 0 0x00.0004 0x00.0000 The application code should have a decision bit that indicates whether the Flash regions are swapped or not. If the FMME bit in the FLASHCONF register is set to 1, then the swap happens immediately and the CPU next memory fetch is from the swapped memory. 8.2.3.4 Protected Flash Memory Registers The user is provided execution protection through 16 pairs of 32-bit wide registers. The policy for each protection form is controlled by individual bits (per policy per block) in the FMPPEn and FMPREn registers. ■ Flash Memory Protection Program Enable (FMPPEn): In the Flash, 16-KB blocks can be individually protected from being programed or erased. Because each bit of the FMPPE register represents a 2-KB block, the application must clear all the bits in one byte to protect one 16-KB block. Execute-only protection can only be programmed in 16-KB increments. For example, to protect the first 16-KB block, bits [7:0] all need to be set to 0s. When bits in the FMPPEn register are set, the corresponding block may be programmed (written) or erased. When bits are cleared, June 18, 2014 609 Texas Instruments-Production Data Internal Memory the corresponding block may not be changed. When a block is protected by clearing bits in both FMPPEn and FMPREn registers, execute-only protection can be achieved. ■ Flash Memory Protection Read Enable (FMPREn): If a bit is set in this register, the corresponding block may be executed or read by software or debuggers. If a bits in this register are cleared and the same block in the FMPREn register is cleared, the corresponding block may only be executed, and contents of the memory block are prohibited from being read as data. FMPREn protection can be programmed in 2-KB increments, unlike the FMPPEn, which must be programmed in 16-KB increments. However, if an application does want to read-protect a 16-KB block, eight bits need to be written from 1s to 0s. The policies may be combined as shown in Table 8-2 on page 610. Table 8-2. Flash Memory Protection Policy Combinations FMPPEn FMPREn Protection 0 0 Execute-only protection. The block may only be executed and may not be written or erased. This mode is used to protect code. 1 0 The block may be written, erased or executed, but not read. This combination is unlikely to be used. 0 1 Read-only protection. The block may be read or executed but may not be written or erased. This mode is used to lock the block from further modification while allowing any read or execute access. 1 1 No protection. The block may be written, erased, executed or read. A Flash memory access that attempts to read a read-protected block (FMPREn bit is clear) is prohibited and generates a bus fault. A Flash memory access that attempts to program or erase a program-protected block (FMPPEn bit is clear) is prohibited and can optionally generate an interrupt (by setting the AMASK bit in the Flash Controller Interrupt Mask (FCIM) register) to alert software developers of poorly behaving software during the development and debug phases. The factory settings for the FMPREn and FMPPEn registers are a value of 1 for all implemented banks. These settings create a policy of open access and programmability. The register bits may be changed by clearing the specific register bit. The changes are not permanent until the register is committed (saved), at which point the bit change is permanent. If a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a any simulated power-on-reset (SIM_POR) event. The changes are committed using the Flash Memory Control (FMC) register. Details on programming these bits are discussed in “Non-Volatile Register Programming-- Flash Memory Resident Registers” on page 613. 8.2.3.5 Execute-Only Protection Execute-only protection prevents both modification and visibility to a protected flash block. This mode is intended to be used in situations where a device requires debug capability, yet portions of the application space must be protected from external access. An example of this is a company that wishes to sell Tiva™ C Series devices with their proprietary software preprogrammed, yet allow the end user to add custom code to an unprotected region of the flash (such as a motor control module with a customizable motor configuration section in flash). Literal data introduces a complication to the protection mechanism. When C code is compiled and linked, literal data (constants, and so on) is typically placed in the text section, between functions, by the compiler. The literal data is accessed at run time through the use of the LDR instruction, which loads the data from memory using a PC-relative memory address. The execution of the LDR instruction generates a read transaction across the Cortex-M3's DCode bus, which is subject to the execute-only protection mechanism. If the accessed block is marked as execute only, the transaction 610 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller is blocked, and the processor is prevented from loading the constant data and, therefore, inhibiting correct execution. Therefore, using execute-only protection requires that literal data be handled differently. There are three ways to address this: 1. Use a compiler that allows literal data to be collected into a separate section that is put into one or more read-enabled flash blocks. Note that the LDR instruction may use a PC-relative address, in which case the literal pool cannot be located outside the span of the offset, or the software may reserve a register to point to the base address of the literal pool and the LDR offset is relative to the beginning of the pool. 2. Use a compiler that generates literal data from arithmetic instruction immediate data and subsequent computation. 3. Use method 1 or 2, but in assembly language, if the compiler does not support either method. 8.2.3.6 Read-Only Protection Read-only protection prevents the contents of the flash block from being re-programmed, while still allowing the content to be read by processor or the debug interface. Note that if a FMPREn bit is cleared, all read accesses to the Flash memory block are disallowed, including any data accesses. Care must be taken not to store required data in a Flash memory block that has the associated FMPREn bit cleared. The read-only mode does not prevent read access to the stored program, but it does provide protection against accidental (or malicious) erasure or programming. Read-only is especially useful for utilities like the boot loader when the debug interface is permanently disabled. In such combinations, the boot loader, which provides access control to the Flash memory, is protected from being erased or modified. 8.2.3.7 Permanently Disabling Debug For extremely sensitive applications, the debug interface to the processor and peripherals can be permanently disabled, blocking all accesses to the device through the JTAG or SWD interfaces. With the debug interface disabled, it is still possible to perform standard IEEE instructions (such as boundary scan operations), but access to the processor and peripherals is blocked. The DBG0 and DBG1 bits of the Boot Configuration (BOOTCFG) register control whether the debug interface is turned on or off. The debug interface should not be permanently disabled without providing some mechanism, such as the boot loader, to provide customer-installable updates or bug fixes. Disabling the debug interface is permanent and cannot be reversed. 8.2.3.8 Interrupts The Flash memory controller can generate interrupts when the following conditions are observed: ■ Programming Interrupt: Signals when a program or erase action is complete. (PRIS). ■ Access Interrupt: Signals when a program or erase action has been attempted on a 16-kB block of memory that is protected by its corresponding FMPPEn bit. (ARIS). ■ EEPROM Interrupt ■ Pump Voltage Interrupt: Indicates if the regulated voltage of the pump went out of specification during a Flash operation and the operation was terminated. (VOLTRIS). June 18, 2014 611 Texas Instruments-Production Data Internal Memory ■ Invalid Data Interrupt: Signals when a bit in Flash that was previously programmed as a 0 is now requested to be programmed as a 1. (INVDRIS). ■ ERASE Operation Interrupt: Indicates an ERASE operation failed. (ERRIS). The interrupt events that can trigger a controller-level interrupt are defined in the Flash Controller Masked Interrupt Status (FCMIS) register (see page 633) by setting the corresponding MASK bits. If interrupts are not used, the raw interrupt status is always visible via the Flash Controller Raw Interrupt Status (FCRIS) register (see page 630). Interrupts are always cleared (for both the FCMIS and FCRIS registers) by writing a 1 to the corresponding bit in the Flash Controller Masked Interrupt Status and Clear (FCMISC) register (see page 635). 8.2.3.9 µDMA The µDMA can be programmed to read from Flash. The Flash DMA Address Size (FLASHDMASZ) register configures 2-KB regions of Flash that can be accessed by the µDMA. The starting address for this µDMA-accessible region is defined in the Flash DMA Starting Address (FLASHDMAST) register. When the DFA bit is set in the FLASHPP register, the µDMA can access the enabled region configured by the FLASHDMASZ and FLASHDMAST registers. The µDMA checks the Flash Protection Program Enable n (FMPPEn) registers for masked 2-KB Flash regions before initiating the transfer. If the access is out of range, then a bus fault is generated. Note: 8.2.3.10 The µDMA can access Flash in Run Mode only (not available in low power modes). Flash Memory Programming The Tiva™ C Series devices provide a user-friendly interface for Flash memory programming. All erase/program operations are handled via three registers: Flash Memory Address (FMA), Flash Memory Data (FMD), and Flash Memory Control (FMC). Note that if the debug capabilities of the microcontroller have been deactivated, resulting in a "locked" state, a recovery sequence must be performed in order to reactivate the debug module. See “Recovering a "Locked" Microcontroller” on page 213. When a Flash memory operation write, page erase, or mass erase is executed in a Flash bank, access to that particular bank pair is inhibited. As a result, instruction and literal fetches to the bank pair are held off until the Flash memory operation is complete. If instruction execution is required during a Flash memory operation, the code that is executing must be placed in SRAM and executed from there while the flash operation is in progress. Note: When programming Flash memory, the following characteristics of the memory must be considered: ■ Only an erase can change bits from 0 to 1. ■ A write can only change bits from 1 to 0. If the write attempts to change a 0 to a 1, the write fails and no bits are changed. ■ All Flash operations are completed before entering sleep or deep sleep. To program a 32-bit word 1. Write source data to the FMD register. 2. Write the target address to the FMA register. 612 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 3. Write the Flash memory write key and the WRITE bit (a value of 0xA442.0001) to the FMC register. The write key may be 0xA442 or the value programmed into the FLPEKEY register depending on the KEY value in the BOOTCFG register. See page 674 and page 640 for more information. 4. Poll the FMC register until the WRITE bit is cleared. To perform an erase of a 16-KB sector 1. Write the 16-KB aligned address to the FMA register. 2. Write the Flash memory write key and the ERASE bit to the FMC register. 3. Poll the FMC register until the ERASE bit is cleared or, alternatively, enable the programming interrupt using the PMASK bit in the FCIM register. To perform a mass erase of the Flash memory 1. Write the Flash memory write key and the MERASE bit to the FMC register. 2. Poll the FMC register until the MERASE bit is cleared or, alternatively, enable the programming interrupt using the PMASK bit in the FCIM register. 8.2.3.11 32-Word Flash Memory Write Buffer A 32-word write buffer provides the capability to perform faster write accesses to the Flash memory by programming two 32-bit words at a time, allowing 32 words to be programmed in the same time as 16 would take using the method described above. The data for the buffered write is written to the Flash Write Buffer (FWBn) registers. The registers are 32-word aligned with Flash memory, and therefore the register FWB0 corresponds with the address in FMA where bits [6:0] of FMA are all 0. FWB1 corresponds with the address in FMA + 0x4 and so on. Only the FWBn registers that have been updated since the previous buffered Flash memory write operation are written. The Flash Write Buffer Valid (FWBVAL) register shows which registers have been written since the last buffered Flash memory write operation. This register contains a bit for each of the 32 FWBn registers, where bit[n] of FWBVAL corresponds to FWBn. The FWBn register has been updated if the corresponding bit in the FWBVAL register is set. To program 32 words with a single buffered Flash memory write operation 1. Write the source data to the FWBn registers. 2. Write the target address to the FMA register. This must be a 32-word aligned address (that is, bits [6:0] in FMA must be 0s). 3. Write the Flash memory write key and the WRBUF bit to the FMC2 register. 4. Poll the FMC2 register until the WRBUF bit is cleared or wait for the PMIS interrupt to be signaled. 8.2.3.12 Non-Volatile Register Programming-- Flash Memory Resident Registers Note: The Boot Configuration (BOOTCFG) register requires a POR before the committed changes take effect. This section discusses how to update the registers shown in Table 8-3 on page 614, which are resident within the Flash Memory. These registers exist in a separate space from the main Flash June 18, 2014 613 Texas Instruments-Production Data Internal Memory memory array and are not affected by an ERASE or MASS ERASE operation. The bits in these registers can be changed from 1 to 0 with a commit operation. The register contents are unaffected by any reset condition except power-on reset, which returns the register contents to 0xFFFF.FFFE for the BOOT Configuration (BOOTCFG) register and 0xFFFF.FFFF for all others. By committing the register values using the COMT bit in the Flash Memory Control (FMC) register, the register contents become non-volatile and are therefore retained following power cycling. Once the register contents are committed, the only way to restore the factory default values is to perform the sequence described in “Recovering a "Locked" Microcontroller” on page 213. All of the FMPREn, FMPPEn and USER_REGn registers, in addition to the BOOTCFG register can be committed in non-volatile memory. The FMPREn, FMPPEn, and USER_REGn registers can be tested before being committed; the BOOTCFG register cannot. To program the BOOTCFG register, the value must be written into the Flash Memory Data (FMD) register before it is committed. The BOOTCFG configuration cannot be tried and verified before committing to non-volatile memory. Important: All Flash memory resident registers can only have bits changed from 1 to 0 by user programming. The FMPREn, FMPPEn and BOOTCFG registers can be committed multiple times, but the USER_REGn registers can only be committed once, after the entire register has been set to 1s. After being committed, the USER_REGn registers can only be returned to their factory default values of all 1s by performing the sequence described in “Recovering a "Locked" Microcontroller” on page 213. The mass erase of the main Flash memory array caused by the sequence is performed prior to restoring these registers. Table 8-3 on page 614 provides the FMA address required for commitment of each of the registers and the source of the data to be written when the FMC register is written with a key value of 0xA442 or the PEKEY value of the FLPEKEY register. The key value used is determined by the KEY bit in the BOOTCFG register at reset. If the KEY value is 0x0, the PEKEY value in the FLPEKEY register is used for commits in the FMC/FMC2 register. If the KEY value is 0x1, the value 0xA442 is used as the WRKEY in the FMC/FMC2 register. If the After writing the COMT bit, the user may poll the FMC register to wait for the commit operation to complete. Note: To ensure non-volatile register data integrity, non-volatile register commits should not be interrupted with a power loss. If data integrity is compromised during a commit because of a power loss, a toggle mass erase function can be performed to clear these registers. See Table 8-3 on page 614 for the list of non-volatile registers. Table 8-3. User-Programmable Flash Memory Resident Registers FMA Value Data Source FMPRE0 Register to be Committed 0x0000.0000 FMPRE0 FMPRE1 0x0000.0002 FMPRE1 FMPRE2 0x0000.0004 FMPRE2 FMPRE3 0x0000.0006 FMPRE3 FMPRE4 0x0000.0008 FMPRE4 FMPRE5 0x0000.000A FMPRE5 FMPRE6 0x0000.000C FMPRE6 FMPRE7 0x0000.000E FMPRE7 FMPRE8 0x0000.0010 FMPRE8 FMPRE9 0x0000.0012 FMPRE9 FMPRE10 0x0000.0014 FMPRE10 614 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 8-3. User-Programmable Flash Memory Resident Registers (continued) Register to be Committed 8.2.4 FMA Value Data Source FMPRE11 0x0000.0016 FMPRE11 FMPRE12 0x0000.0018 FMPRE12 FMPRE13 0x0000.001A FMPRE13 FMPRE14 0x0000.001C FMPRE14 FMPRE15 0x0000.001E FMPRE15 FMPPE0 0x0000.0001 FMPPE0 FMPPE1 0x0000.0003 FMPPE1 FMPPE2 0x0000.0005 FMPPE2 FMPPE3 0x0000.0007 FMPPE3 FMPPE4 0x0000.0009 FMPPE4 FMPPE5 0x0000.000B FMPPE5 FMPPE6 0x0000.000D FMPPE6 FMPPE7 0x0000.000F FMPPE7 FMPPE8 0x0000.00011 FMPPE8 FMPPE9 0x0000.00013 FMPPE9 FMPPE10 0x0000.00015 FMPPE10 FMPPE11 0x0000.00017 FMPPE11 FMPPE12 0x0000.00019 FMPPE12 FMPPE13 0x0000.0001B FMPPE13 FMPPE14 0x0000.0001D FMPPE14 FMPPE15 0x0000.0001F FMPPE15 USER_REG0 0x8000.0000 USER_REG0 USER_REG1 0x8000.0001 USER_REG1 USER_REG2 0x8000.0002 USER_REG2 USER_REG3 0x8000.0003 USER_REG3 BOOTCFG 0x7510.0000 FMD EEPROM The TM4C1294NCPDT microcontroller includes an EEPROM with the following features: ■ 6Kbytes of memory accessible as 1536 32-bit words ■ 96 blocks of 16 words (64 bytes) each ■ Built-in wear leveling ■ Access protection per block ■ Lock protection option for the whole peripheral as well as per block using 32-bit to 96-bit unlock codes (application selectable) ■ Interrupt support for write completion to avoid polling ■ Endurance of 500K writes (when writing at fixed offset in every alternate page in circular fashion) to 15M operations (when cycling through two pages ) per each 2-page block. June 18, 2014 615 Texas Instruments-Production Data Internal Memory 8.2.4.1 Functional Description The EEPROM module provides a well-defined register interface to support accesses to the EEPROM with both a random access style of read and write as well as a rolling or sequential access scheme. A protection mechanism allows locking EEPROM blocks to prevent writes under a set of circumstances as well as reads under the same or different circumstances. The password model allows the application to lock one or more EEPROM blocks to control access on 16-word boundaries. Blocks There are 96 blocks of 16 words each in the EEPROM. These are readable and writable as words. Bytes and half-words can be read, and these accesses do not have to occur on a word boundary. The entire word is read and any unneeded data is simply ignored. The EEPROM blocks are writable only on a word basis. To write a byte, it is necessary to read the word value, modify the appropriate byte, and write the word back. Each block is addressable as an offset within the EEPROM, using a block select register. Each word is offset addressable within the selected block. The current block is selected by the EEPROM Current Block (EEBLOCK) register. The current offset is selected and checked for validity by the EEPROM Current Offset (EEOFFSET) register. The application may write the EEOFFSET register any time, and it is also automatically incremented when the EEPROM Read-Write with Increment (EERDWRINC) register is accessed. However, the EERDWRINC register does not increment the block number, but instead wraps within the block. Blocks are individually protectable. Attempts to read from a block for which the application does not have permission return 0xFFFF.FFFF. Attempts to write into a block for which the application does not have permission results in an error in the EEPROM Done Status (EEDONE) register. Timing Considerations After enabling or resetting the EEPROM module, software must wait until the WORKING bit in the EEDONE register is clear before accessing any EEPROM registers. Note: Software must ensure there are no Flash memory writes or erases pending before performing an EEPROM operation. When the FMC register reads as 0x0000.00000 and the WRBUF bit of the FMC2 register is clear, there are no Flash memory writes or erases pending. EEPROM operations must be completed before entering Sleep or Deep-Sleep mode. Ensure the EEPROM operations have completed by checking the EEPROM Done Status (EEDONE) register before issuing a WFI instruction to enter Sleep or Deep-Sleep. Writes to words within a block are delayed by a variable amount of time. The application may use an interrupt to be notified when the write is done, or alternatively poll for the done status in the EEDONE register. The variability ranges from the write timing of the EEPROM to the erase timing of EEPROM, where the erase timing is less than the write timing of most external EEPROMs. Depending on the CPU frequency, the application must program the EEPROM Clock High Time (EBCHT), EEPROM Bank Clock Edge (EBCE) and the EEPROM Wait States (EWS) in the Memory Timing Parameter Register 0 for Main Flash and EEPROM (MEMTIM0) register at System Control Module offset 0x0C0. 616 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 8-4. MEMTIM0 Register Configuration versus Frequency CPU Frequency range (f) Time Period Range (t) in ns EEPROM Bank Clock in MHz High Time (EBCHT) Note: EEPROM Bank Clock Edge (EBCE) EEPROM Wait States (EWS) 16 62.5 0x0 1 0x0 16 < f ≤ 40 62.5 > t ≥ 25 0x2 0 0x1 40 < f ≤60 25 > t ≥ 16.67 0x3 0 0x2 60< f ≤80 16.67 > t ≥ 12.5 0x4 0 0x3 80 < f ≤100 12.5 > t ≥ 10 0x5 0 0x4 100< f ≤120 10 > t ≥ 8.33 0x6 0 0x5 The associated Flash and EEPROM fields in the MEMTIM0 register must be programmed to the same values. For example, the FWS field must be programmed to the same value as the EWS field. Locking and Passwords The EEPROM can be locked at both the module level and the block level. The lock is controlled by a password that is stored in the EEPROM Password (EEPASSn) registers and can be any 32-bit to 96-bit value other than all 1s. Block 0 is the master block, the password for block 0 protects the control registers as well as all other blocks. Each block can be further protected with a password for that block. If a password is registered for block 0, then the whole module is locked at reset. As a result, the EEBLOCK register cannot be changed from 0 until block 0 is unlocked. A password registered with any block, including block 0, allows for protection rules that control access of that block based on whether it is locked or unlocked. Generally, the lock can be used to prevent write accesses when locked or can prevent read and write accesses when locked. All password protected blocks are locked at reset. To unlock a block, the correct password value must be written to the EEPROM Unlock (EEUNLOCK) register by writing to it once, twice, or three times, depending on the size of the password. A block or the module may be re-locked by writing 0xFFFF.FFFF to the EEUNLOCK register because 0xFFFF.FFFF is not a valid password. Protection and Access Control The PROT protection field in the EEPROM Protection (EEPROT) register provides discrete control of read and write access for each block which allows various protection models per block. The protection configurations allowed are as follows: ■ PROT = 0x0 – Without password: Readable and writable at any time. This mode is the default when there is no password. – With password: Readable, but only writable when unlocked by the password. This mode is the default when there is a password. ■ PROT = 0x1 – With password: Readable or writable only when unlocked. – This value has no meaning when there is no password. June 18, 2014 617 Texas Instruments-Production Data Internal Memory ■ PROT = 0x2 – Without password: Readable but not writable. – With password: Readable only when unlocked, not writable under any conditions. Additionally, access protection may be applied based on the processor mode. This configuration allows for supervisor-only access or supervisor and user access, which is the default. Supervisor-only access mode also prevents access by the µDMA and Debugger. Additionally, the master block may be used to control access protection for the protection mechanism itself. If access control for block 0 is for supervisor only, then the whole module may only be accessed in supervisor mode. Hidden Blocks Hiding provides a temporary form of protection. Every block except block 0 can be hidden, which prevents all accesses until the next reset. This mechanism can allow a boot or initialization routine to access some data which is then made inaccessible to all further accesses. Because boot and initialization routines control the capabilities of the application, hidden blocks provide a powerful isolation of the data when debug is disabled. A typical use model would be to have the initialization code store passwords, keys, and/or hashes to use for verification of the rest of the application. Once performed, the block is then hidden and made inaccessible until the next reset which then re-enters the initialization code. Power and Reset Safety Once the EEDONE register indicates that a location has been successfully written, the data is retained until that location is written again. There is no power or reset race after the EEDONE register indicates a write has completed. Interrupt Control The EEPROM module allows for an interrupt when a write completes to prevent the use of polling. The interrupt can be used to drive an application ISR which can then write more words or verify completion. The interrupt mechanism is used any time the EEDONE register goes from working to done, whether because of an error or the successful completion of a program or erase operation. This interrupt mechanism works for data writes, writes to password and protection registers, and mass erase using the EEPROM Debug Mass Erase (EEDGBME) register. The EEPROM interrupt is signaled to the core using the Flash memory interrupt vector. Software can determine that the source of the interrupt was the EEPROM by examining bit 2 of the Flash Controller Masked Interrupt Status and Clear (FCMISC) register. Theory of Operation The EEPROM operates using a traditional bank model which implements EEPROM-type cells, but uses sector erase. Additionally, words are replicated in the blocks to allow 500K+ erase cycles when needed, which means that each word has a latest version. As a result, a write creates a new version of the word in a new location, making the previous value obsolete. When a block runs out of room to store the latest version of a word, a copy buffer is used. The copy buffer copies the latest words of each block. The original block is then erased. Finally, the copy buffer contents are copied back to the block. The EEPROM module includes functionality to prevent data corruption due to power-loss or a brown-out event during programming or erase operations. These conditions prevent corruption of 618 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller non-targeted memory areas but cannot guarantee that the operation is completed successfully. Refer to “EEPROM” on page 1848 for important timing information on EEPROM protection. The EEPROM mechanism properly tracks all state information to provide complete safety and protection. Although it should not normally be possible, errors during programming can occur in certain circumstances, for example, the voltage rail dropping during programming. In these cases, the EESUPP register can be used to know if a program or an erase had failed. Debug Mass Erase The EEPROM debug mass erase allows the developer to mass erase the EEPROM. For the mass erase to occur correctly, there can be no active EEPROM operations. After the last EEPROM operation, the application must ensure that no EEPROM registers are updated, including modifying the EEBLOCK and the EEOFFSET registers without doing an actual read or write operation. To hold off these operations, the application should reset the EEPROM module by setting the R0 bit in the EEPROM Software Reset (SREEPROM) register, wait until WORKING bit in the EEPROM Done Status (EEDONE) register is clear, and then enable the debug mass erase by setting the ME bit in the EEPROM Debug Mass Erase (EEDBGME) register. Error During Programming Operations such as data-write, password set, protection set, and copy buffer erase may perform multiple operations. For example, a normal write performs two underlying writes: the control word write and the data write. If the control word writes but the data fails (for example, due to a voltage drop), the overall write fails with indication provided in the EEDONE register. Failure and the corrective action is broken down by the type of operation: ■ If a normal write fails such that the control word is written but the data fails to write, the safe course of action is to retry the operation once the system is otherwise stable, for example, when the voltage is stabilized. After the retry, the control word and write data are advanced to the next location. ■ If a password or protection write fails, the safe course of action is to retry the operation once the system is otherwise stable. In the event that multi-word passwords may be written outside of a manufacturing or bring-up mode, care must be taken to ensure all words are written in immediate succession. If not, then partial password unlock would need to be supported to recover. ■ If the word write requires the block to be written to the copy buffer, then it is possible to fail or lose power during the subsequent operations. A control word mechanism is used to track what step the EEPROM was in if a failure occurs. If not completed, the EESUPP register indicates the partial completion. After a reset and prior to writing any data to the EEPROM, software must read the EESUPP register and check for the presence of any error condition which may indicate that a write or erase was in progress when the system was reset due to a voltage drop. If either the PRETRY or ERETRY bits are set, the peripheral should be reset by setting and then clearing the R0 bit in the EEPROM Software Reset (SREEPROM) register and waiting for the WORKING bit in the EEDONE register to clear before again checking the EESUPP register for error indicators. This procedure should allow the EEPROM to recover from the write or erase error. In very isolated cases, the EESUPP register may continue to register an error after this operation, in which case the reset should be repeated. After recovery, the application should rewrite the data which was being programmed when the initial failure occurred. Soft Reset Handling The following soft resets should not be asserted during an EEPROM program or erase operation: June 18, 2014 619 Texas Instruments-Production Data Internal Memory ■ Software reset (SYSRESREQ) ■ Software peripheral reset ■ Watchdog reset (if configured as a system reset in the RESBEHAVCTL register) ■ MOSC failure reset ■ BOR reset (if configured as a system reset in the RESBEHAVCTL register) ■ External reset (if configured as a system reset in the RESBEHAVCTL register) ■ Writes to the HSSR register The WORKING bit of the EEDONE register can be checked before the reset is asserted to see if an EEPROM program or erase operation is occurring. Soft resets may occur when using a debugger and should be avoided during an EEPROM operation. A reset such as the Watchdog reset can be mapped to an external reset using a GPIO, or Hibernate can be entered, if time is not a concern. Endurance Endurance is per meta-block which is 8 blocks. Endurance is measured in two ways: 1. To the application, it is the number of writes that can be performed. 2. To the microcontroller, it is the number of erases that can be performed on the meta-block. Because of the second measure, the number of writes depends on how the writes are performed. For example: ■ One word can be written more than 500K times, but, these writes impact the meta-block that the word is within. As a result, writing one word 500K times, then trying to write a nearby word 500K times is not assured to work. To ensure success, the words should be written more in parallel. ■ All words can be written in a sweep with a total of more than 500K sweeps which updates all words more than 500K times. ■ Different words can be written such that any or all words can be written more than 500K times when write counts per word stay about the same. For example, offset 0 could be written 3 times, then offset 1 could be written 2 times, then offset 2 is written 4 times, then offset 1 is written twice, then offset 0 is written again. As a result, all 3 offsets would have 4 writes at the end of the sequence. This kind of balancing within 7 writes maximizes the endurance of different words within the same meta-block. 8.2.4.2 EEPROM Initialization and Configuration Before writing to any EEPROM registers, the clock to the EEPROM module must be enabled through the EEPROM Run Mode Clock Gating Control (RCGCEEPROM) register (see page 400) and the following initialization steps must be executed: 1. Insert delay (6 cycles plus function call overhead). 2. Poll the WORKING bit in the EEPROM Done Status (EEDONE) register until it is clear, indicating that the EEPROM has completed its power-on initialization. When WORKING=0, continue. 620 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 3. Read the PRETRY and ERETRY bits in the EEPROM Support Control and Status (EESUPP) register. If either of the bits are set, return an error, else continue. 4. Reset the EEPROM module using the EEPROM Software Reset (SREEPROM) register at offset 0x558 in the System Control register space. 5. Insert delay (6 cycles plus function call overhead). 6. Poll the WORKING bit in the EEPROM Done Status (EEDONE) register to determine when it is clear. When WORKING=0, continue. 7. Read the PRETRY and ERETRY bits in the EESUPP register. If either of the bits are set, return an error, else the EEPROM initialization is complete and software may use the peripheral as normal. Important: Failure to perform these initialization steps after a reset may lead to incorrect operation or permanent data loss if the EEPROM is later written. If the PRETRY or ERETRY bits are set in the ESUPP register, the EEPROM was unable to recover its state. If power is stable when this occurs, this indicates a fatal error and is likely an indication that the EEPROM memory has exceeded its specified lifetime write/erase specification. If the supply voltage is unstable when this return code is observed, retrying the operation once the voltage is stabilized may clear the error. The EEPROM initialization function code is named EEPROMinit( ) in TivaWare, which can be downloaded from http://www.ti.com/tivaware. 8.2.5 Bus Matrix Memory Accesses The following table identifies the Bus Masters and their access to the various memories on the bus matrix. Table 8-5. Master Memory Access Availability 8.3 Master Flash Access ROM Access SRAM Access EEPROM Access External Memory Access (via EPI) CPU Instruction Bus Yes Yes (read-only) Yes Yes Yes CPU Data Bus Yes Yes (read-only) - Yes Yes µDMA Yes (read-only, Run-Mode-only) - Yes Yes Yes Ethernet Module - - Yes - - USB - - Yes - - Register Map Table 8-6 on page 622 lists the ROM Controller register and the Flash memory control registers. The offset listed is a hexadecimal increment to the register's address. The Flash memory register offsets are relative to the Flash memory control base address of 0x400F.D000. The EEPROM registers are relative to the EEPROM base address of 0x400A.F000. The ROM control and Flash memory protection register offsets are relative to the System Control base address of 0x400F.E000. June 18, 2014 621 Texas Instruments-Production Data Internal Memory Table 8-6. Flash Register Map Offset Name Type Reset See page Description Internal Memory Registers (Internal Memory Control Offset) 0x000 FMA RW 0x0000.0000 Flash Memory Address 625 0x004 FMD RW 0x0000.0000 Flash Memory Data 626 0x008 FMC RW 0x0000.0000 Flash Memory Control 627 0x00C FCRIS RO 0x0000.0000 Flash Controller Raw Interrupt Status 630 0x010 FCIM RW 0x0000.0000 Flash Controller Interrupt Mask 633 0x014 FCMISC RW1C 0x0000.0000 Flash Controller Masked Interrupt Status and Clear 635 0x020 FMC2 RW 0x0000.0000 Flash Memory Control 2 638 0x030 FWBVAL RW 0x0000.0000 Flash Write Buffer Valid 639 0x03C FLPEKEY RO 0x0000.FFFF Flash Program/Erase Key 640 0x100 0x17C FWBn RW 0x0000.0000 Flash Write Buffer n 641 0xFC0 FLASHPP RO 0xF014.01FF Flash Peripheral Properties 642 0xFC4 SSIZE RO 0x0000.03FF SRAM Size 644 0xFC8 FLASHCONF RW 0x0000.0000 Flash Configuration Register 645 0xFCC ROMSWMAP RO 0x0000.0000 ROM Third-Party Software 647 0xFD0 FLASHDMASZ RW 0x0000.0000 Flash DMA Address Size 649 0xFD4 FLASHDMAST RW 0x0000.0000 Flash DMA Starting Address 650 EEPROM Registers (EEPROM Control Offset) 0x000 EESIZE RO 0x0060.0600 EEPROM Size Information 651 0x004 EEBLOCK RW 0x0000.0000 EEPROM Current Block 652 0x008 EEOFFSET RW 0x0000.0000 EEPROM Current Offset 653 0x010 EERDWR RW - EEPROM Read-Write 654 0x014 EERDWRINC RW - EEPROM Read-Write with Increment 655 0x018 EEDONE RO 0x0000.0000 EEPROM Done Status 656 0x01C EESUPP RW - EEPROM Support Control and Status 658 0x020 EEUNLOCK RW - EEPROM Unlock 659 0x030 EEPROT RW 0x0000.0000 EEPROM Protection 660 0x034 EEPASS0 RW - EEPROM Password 662 0x038 EEPASS1 RW - EEPROM Password 662 0x03C EEPASS2 RW - EEPROM Password 662 0x040 EEINT RW 0x0000.0000 EEPROM Interrupt 663 622 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 8-6. Flash Register Map (continued) Offset Name 0x050 Description See page Type Reset EEHIDE0 RW 0x0000.0000 EEPROM Block Hide 0 664 0x054 EEHIDE1 RW 0x0000.0000 EEPROM Block Hide 1 665 0x058 EEHIDE2 RW 0x0000.0000 EEPROM Block Hide 2 665 0x080 EEDBGME RW 0x0000.0000 EEPROM Debug Mass Erase 666 0xFC0 EEPROMPP RO 0x0000.01FF EEPROM Peripheral Properties 667 Memory Registers (System Control Offset) 0x0D4 RVP RO 0x0101.FFF0 Reset Vector Pointer 668 0x1D0 BOOTCFG RO 0xFFFF.FFFE Boot Configuration 674 0x1E0 USER_REG0 W0 0xFFFF.FFFF User Register 0 677 0x1E4 USER_REG1 W0 0xFFFF.FFFF User Register 1 677 0x1E8 USER_REG2 W0 0xFFFF.FFFF User Register 2 677 0x1EC USER_REG3 W0 0xFFFF.FFFF User Register 3 677 0x200 FMPRE0 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 0 669 0x204 FMPRE1 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 1 669 0x208 FMPRE2 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 2 669 0x20C FMPRE3 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 3 669 0x210 FMPRE4 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 4 669 0x214 FMPRE5 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 5 669 0x218 FMPRE6 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 6 669 0x21C FMPRE7 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 7 669 0x220 FMPRE8 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 8 669 0x224 FMPRE9 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 9 669 0x228 FMPRE10 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 10 669 0x22C FMPRE11 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 11 669 0x230 FMPRE12 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 12 669 0x234 FMPRE13 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 13 669 0x238 FMPRE14 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 14 669 0x23C FMPRE15 RW 0xFFFF.FFFF Flash Memory Protection Read Enable 15 669 0x400 FMPPE0 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 0 671 0x404 FMPPE1 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 1 671 0x408 FMPPE2 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 2 671 0x40C FMPPE3 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 3 671 June 18, 2014 623 Texas Instruments-Production Data Internal Memory Table 8-6. Flash Register Map (continued) Offset Name 0x410 Reset FMPPE4 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 4 671 0x414 FMPPE5 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 5 671 0x418 FMPPE6 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 6 671 0x41C FMPPE7 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 7 671 0x420 FMPPE8 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 8 671 0x424 FMPPE9 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 9 671 0x428 FMPPE10 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 10 671 0x42C FMPPE11 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 11 671 0x430 FMPPE12 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 12 671 0x434 FMPPE13 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 13 671 0x438 FMPPE14 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 14 671 0x43C FMPPE15 RW 0xFFFF.FFFF Flash Memory Protection Program Enable 15 671 8.4 Description See page Type Internal Memory Register Descriptions (Internal Memory Control Offset) This section lists and describes the memory control registers, in numerical order by address offset. Registers in this section are relative to the memory control base address of 0x400F.D000. 624 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: Flash Memory Address (FMA), offset 0x000 During a write operation, this register contains a 4-byte-aligned address and specifies where the data is written. During erase operations for flash space that is not user configurable (that is, FMPREn, FMPPEn, USER_REGn, BOOTCFG), this register contains a 16 KB-aligned CPU byte address and specifies which block is erased. Note that the alignment requirements must be met by software or the results of the operation are unpredictable. Flash Memory Address (FMA) Base 0x400F.D000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RW 0 RW 0 RW 0 RW 0 RW 0 25 24 23 22 21 20 19 18 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset 17 16 OFFSET OFFSET Type Reset Bit/Field Name Type Reset Description 31:20 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19:0 OFFSET RW 0x0 Address Offset Address offset in Flash memory where operation is performed, except for non-volatile registers (see “Non-Volatile Register Programming-Flash Memory Resident Registers” on page 613 for details on values for this field). June 18, 2014 625 Texas Instruments-Production Data Internal Memory Register 2: Flash Memory Data (FMD), offset 0x004 This register contains the data to be written during the programming cycle. Note that the contents of this register are undefined for a read access of an execute-only block. This register is not used during erase cycles. Flash Memory Data (FMD) Base 0x400F.D000 Offset 0x004 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 DATA Type Reset DATA Type Reset Bit/Field Name Type 31:0 DATA RW Reset Description 0x0000.0000 Data Value Data value for write operation. 626 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: Flash Memory Control (FMC), offset 0x008 When this register is written, the Flash memory controller initiates the appropriate access cycle for the location specified by the Flash Memory Address (FMA) register (see page 625). If the access is a write access, the data contained in the Flash Memory Data (FMD) register (see page 626) is written to the specified address. For non-volatile registers, FMPREn, FMPPEn, USER_REGn, and USER_REGn, the respective register is programmed with the value to be written rather than the FMD register. This register must be the final register written and initiates the memory operation. The four control bits in the lower byte of this register are used to initiate memory operations. Care must be taken not to set multiple control bits as the results of such an operation are unpredictable. Flash Memory Control (FMC) Base 0x400F.D000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO 0 WO 0 WO 0 WO 0 WRKEY Type Reset WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:16 WRKEY WO 0x0000 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 COMT MERASE ERASE WRITE RW 0 RW 0 RW 0 RW 0 Description Flash Memory Write Key This field contains a write key, which is used to minimize the incidence of accidental Flash memory writes. The value 0xA442 or the PEKEY value in the FLPEKEY register must be written into this field for a Flash memory write to occur. The use of 0xA442 or PEKEY is dependent on the value of the KEY bit in the BOOTCFG register at 0x1D0. Writes to the FMC register without this WRKEY value are ignored. A read of this field returns the value 0. 15:4 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 627 Texas Instruments-Production Data Internal Memory Bit/Field Name Type Reset 3 COMT RW 0 Description Commit Register Value This bit is used to commit writes to Flash-memory-resident registers and to monitor the progress of that process. Value Description 0 A write of 0 has no effect on the state of this bit. When read, a 0 indicates that the previous commit access is complete. 1 Set this bit to commit (write) the register value to a Flash-memory-resident register. When read, a 1 indicates that the previous commit access is not complete. See “Non-Volatile Register Programming-- Flash Memory Resident Registers” on page 613 for more information on programming Flash-memory-resident registers. 2 MERASE RW 0 Mass Erase Flash Memory This bit is used to mass erase the Flash main memory and to monitor the progress of that process. Value Description 0 A write of 0 has no effect on the state of this bit. When read, a 0 indicates that the previous mass erase access is complete. 1 Set this bit to erase the Flash main memory. When read, a 1 indicates that the previous mass erase access is not complete. For information on erase time, see “Flash Memory” on page 1847. 1 ERASE RW 0 Erase a Page of Flash Memory This bit is used to erase a page of Flash memory and to monitor the progress of that process. Value Description 0 A write of 0 has no effect on the state of this bit. When read, a 0 indicates that the previous page erase access is complete. 1 Set this bit to erase the Flash memory page specified by the contents of the FMA register. When read, a 1 indicates that the previous page erase access is not complete. For information on erase time, see “Flash Memory” on page 1847. 628 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 WRITE RW 0 Description Write a Word into Flash Memory This bit is used to write a word into Flash memory and to monitor the progress of that process. Value Description 0 A write of 0 has no effect on the state of this bit. When read, a 0 indicates that the previous write update access is complete. 1 Set this bit to write the data stored in the FMD register into the Flash memory location specified by the contents of the FMA register. When read, a 1 indicates that the write update access is not complete. For information on programming time, see “Flash Memory” on page 1847. June 18, 2014 629 Texas Instruments-Production Data Internal Memory Register 4: Flash Controller Raw Interrupt Status (FCRIS), offset 0x00C This register indicates that the Flash memory controller has an interrupt condition. An interrupt is sent to the interrupt controller only if the corresponding FCIM register bit is set. Flash Controller Raw Interrupt Status (FCRIS) Base 0x400F.D000 Offset 0x00C Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 ERIS PRIS ARIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 PROGRIS reserved RO 0 RO 0 ERRIS INVDRIS VOLTRIS RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:14 reserved RO 0x0000.000 13 PROGRIS RO 0 reserved Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Program Verify Error Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 An interrupt is pending because the verify of a PROGRAM operation failed. If this error occurs when using the Flash write buffer, software must inspect the affected words to determine where the error occurred. This bit is cleared by writing a 1 to the PROGMISC bit in the FCMISC register. 12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 ERRIS RO 0 Erase Verify Error Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 An interrupt is pending because the verify of an ERASE operation failed. If this error occurs when using the Flash write buffer, software must inspect the affected words to determine where the error occurred. This bit is cleared by writing a 1 to the ERMISC bit in the FCMISC register. 630 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 10 INVDRIS RO 0 Description Invalid Data Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 An interrupt is pending because a bit that was previously programmed as a 0 is now being requested to be programmed as a 1. This bit is cleared by writing a 1 to the INVMISC bit in the FCMISC register. 9 VOLTRIS RO 0 Pump Voltage Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 An interrupt is pending because the regulated voltage of the pump went out of spec during the Flash operation and the operation was terminated. This bit is cleared by writing a 1 to the VOLTMISC bit in the FCMISC register. 8:3 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 ERIS RO 0 EEPROM Raw Interrupt Status This bit provides status EEPROM operation. Value Description 0 An EEPROM interrupt has not occurred. 1 An EEPROM interrupt has occurred. This bit is cleared by writing a 1 to the EMISC bit in the FCMISC register. 1 PRIS RO 0 Programming Raw Interrupt Status This bit provides status on programming cycles which are write or erase actions generated through the FMC or FMC2 register bits (see page 627 and page 638). Value Description 0 The programming or erase cycle has not completed. 1 The programming or erase cycle has completed. This status is sent to the interrupt controller when the PMASK bit in the FCIM register is set. This bit is cleared by writing a 1 to the PMISC bit in the FCMISC register. June 18, 2014 631 Texas Instruments-Production Data Internal Memory Bit/Field Name Type Reset 0 ARIS RO 0 Description Access Raw Interrupt Status Value Description 0 No access has tried to improperly program or erase the Flash memory. 1 A program or erase action was attempted on a block of Flash memory that contradicts the protection policy for that block as set in the FMPPEn registers. This status is sent to the interrupt controller when the AMASK bit in the FCIM register is set. This bit is cleared by writing a 1 to the AMISC bit in the FCMISC register. 632 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: Flash Controller Interrupt Mask (FCIM), offset 0x010 This register controls whether the Flash memory controller generates interrupts to the controller. Flash Controller Interrupt Mask (FCIM) Base 0x400F.D000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 EMASK PMASK AMASK RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 RO 0 PROGMASK reserved ERMASK INVDMASK VOLTMASK RW 0 RO 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:14 reserved RO 0x0000.000 13 PROGMASK RW 0 reserved Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Program Verify Error Interrupt Mask Value Description 0 The PROGRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PROGRIS bit is set. 12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 ERMASK RW 0 Erase Verify Error Interrupt Mask Value Description 10 INVDMASK RW 0 0 The ERRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the ERRIS bit is set. Invalid Data Interrupt Mask Value Description 0 The INVDRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the INVDRIS bit is set. June 18, 2014 633 Texas Instruments-Production Data Internal Memory Bit/Field Name Type Reset 9 VOLTMASK RW 0 Description Pump Voltage Interrupt Mask Value Description 0 The VOLTRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the VOLTRIS bit is set. 8:3 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 EMASK RW 0 EEPROM Interrupt Mask Value Description 1 PMASK RW 0 0 The ERIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the ERIS bit is set. Programming Interrupt Mask This bit controls the reporting of the programming raw interrupt status to the interrupt controller. Value Description 0 AMASK RW 0 0 The PRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PRIS bit is set. Access Interrupt Mask This bit controls the reporting of the access raw interrupt status to the interrupt controller. Value Description 0 The ARIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the ARIS bit is set. 634 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 6: Flash Controller Masked Interrupt Status and Clear (FCMISC), offset 0x014 This register provides two functions. First, it reports the cause of an interrupt by indicating which interrupt source or sources are signalling the interrupt. Second, it serves as the method to clear the interrupt reporting. Flash Controller Masked Interrupt Status and Clear (FCMISC) Base 0x400F.D000 Offset 0x014 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 15 14 reserved Type Reset RO 0 RO 0 RO 0 RO 0 13 12 PROGMISC reserved RW1C 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 6 5 4 3 ERMISC INVDMISC VOLTMISC RW1C 0 RW1C 0 RW1C 0 Bit/Field Name Type Reset 31:14 reserved RO 0x0000.000 13 PROGMISC RW1C 0 reserved RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 2 1 0 EMISC PMISC AMISC RW1C 0 RW1C 0 RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PROGVER Masked Interrupt Status and Clear Value Description 0 When read, a 0 indicates that an interrupt has not occurred. A write of 0 has no effect on the state of this bit. 1 When read, a 1 indicates that an unmasked interrupt was signaled. Writing a 1 to this bit clears PROGMISC and also the PROGRIS bit in the FCRIS register (see page 630). 12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 ERMISC RW1C 0 ERVER Masked Interrupt Status and Clear Value Description 0 When read, a 0 indicates that an interrupt has not occurred. A write of 0 has no effect on the state of this bit. 1 When read, a 1 indicates that an unmasked interrupt was signaled. Writing a 1 to this bit clears ERMISC and also the ERRIS bit in the FCRIS register (see page 630). June 18, 2014 635 Texas Instruments-Production Data Internal Memory Bit/Field Name Type Reset 10 INVDMISC RW1C 0 Description Invalid Data Masked Interrupt Status and Clear Value Description 0 When read, a 0 indicates that an interrupt has not occurred. A write of 0 has no effect on the state of this bit. 1 When read, a 1 indicates that an unmasked interrupt was signaled. Writing a 1 to this bit clears INVDMISC and also the INVDRIS bit in the FCRIS register (see page 630). 9 VOLTMISC RW1C 0 VOLT Masked Interrupt Status and Clear Value Description 0 When read, a 0 indicates that an interrupt has not occurred. A write of 0 has no effect on the state of this bit. 1 When read, a 1 indicates that an unmasked interrupt was signaled. Writing a 1 to this bit clears VOLTMISC and also the VOLTRIS bit in the FCRIS register (see page 630). 8:3 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 EMISC RW1C 0 EEPROM Masked Interrupt Status and Clear Value Description 0 When read, a 0 indicates that an interrupt has not occurred. A write of 0 has no effect on the state of this bit. 1 When read, a 1 indicates that an unmasked interrupt was signaled. Writing a 1 to this bit clears EMISC and also the ERIS bit in the FCRIS register (see page 630). 1 PMISC RW1C 0 Programming Masked Interrupt Status and Clear Value Description 0 When read, a 0 indicates that a programming cycle complete interrupt has not occurred. A write of 0 has no effect on the state of this bit. 1 When read, a 1 indicates that an unmasked interrupt was signaled because a programming cycle completed. Writing a 1 to this bit clears PMISC and also the PRIS bit in the FCRIS register (see page 630). 636 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 AMISC RW1C 0 Description Access Masked Interrupt Status and Clear Value Description 0 When read, a 0 indicates that no improper accesses have occurred. A write of 0 has no effect on the state of this bit. 1 When read, a 1 indicates that an unmasked interrupt was signaled because a program or erase action was attempted on a block of Flash memory that contradicts the protection policy for that block as set in the FMPPEn registers. Writing a 1 to this bit clears AMISC and also the ARIS bit in the FCRIS register (see page 630). June 18, 2014 637 Texas Instruments-Production Data Internal Memory Register 7: Flash Memory Control 2 (FMC2), offset 0x020 When this register is written, the Flash memory controller initiates the appropriate access cycle for the location specified by the Flash Memory Address (FMA) register (see page 625). If the access is a write access, the data contained in the Flash Write Buffer (FWB) registers is written. This register must be the final register written as it initiates the memory operation. Flash Memory Control 2 (FMC2) Base 0x400F.D000 Offset 0x020 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 8 7 6 5 4 3 2 1 WRKEY Type Reset WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 15 14 13 12 11 10 9 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:16 WRKEY WO 0x0000 RO 0 0 WRBUF RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 Description Flash Memory Write Key This field contains a write key, which is used to minimize the incidence of accidental Flash memory writes. There are two options for the WRKEY value: If the KEY value in the BOOTCFG register is 0x1 at reset, the value 0xA442 is used as a key enable to initiate the appropriate access cycle for the location specified by the address in the FMA register. If the KEY value in the BOOTCFG register is 0x0 at reset, the value programmed in the FLPEKEY register is used as a key enable to initiate the appropriate access cycle for the location specified by the address in the FMA register. Writes to the FMC2 register without this WRKEY value are ignored. A read of this field returns the value 0. 15:1 reserved RO 0x000 0 WRBUF RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Buffered Flash Memory Write This bit is used to start a buffered write to Flash memory. Value Description 0 A write of 0 has no effect on the state of this bit. When read, a 0 indicates that the previous buffered Flash memory write access is complete. 1 Set this bit to write the data stored in the FWBn registers to the location specified by the contents of the FMA register. When read, a 1 indicates that the previous buffered Flash memory write access is not complete. For information on programming time, see “Flash Memory” on page 1847. 638 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: Flash Write Buffer Valid (FWBVAL), offset 0x030 This register provides a bitwise status of which FWBn registers have been written by the processor since the last write of the Flash memory write buffer. The entries with a 1 are written on the next write of the Flash memory write buffer. This register is cleared after the write operation by hardware. A protection violation on the write operation also clears this status. Software can program the same 32 words to various Flash memory locations by setting the FWB[n] bits after they are cleared by the write operation. The next write operation then uses the same data as the previous one. In addition, if a FWBn register change should not be written to Flash memory, software can clear the corresponding FWB[n] bit to preserve the existing data when the next write operation occurs. Flash Write Buffer Valid (FWBVAL) Base 0x400F.D000 Offset 0x030 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 FWB[n] Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 FWB[n] Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:0 FWB[n] RW 0x0 RW 0 Description Flash Memory Write Buffer Value Description 0 The corresponding FWBn register has no new data to be written. 1 The corresponding FWBn register has been updated since the last buffer write operation and is ready to be written to Flash memory. Bit 0 corresponds to FWB0, offset 0x100, and bit 31 corresponds to FWB31, offset 0x13C. June 18, 2014 639 Texas Instruments-Production Data Internal Memory Register 9: Flash Program/Erase Key (FLPEKEY), offset 0x03C This register provides a mechanism for protection from inadvertent writes to flash by supplying a 16-bit key . If the KEY value in the BOOTCFG register is 0, then this value is used as the 16-bit key in place of 0xA442 in the FMC/FMC2 registers for committed flash writes. This can be used for cases where a new image is downloaded and the first word of the new image has the 16-bit key value to be used for that product. This 16-bit key is used to allow the write to FMC or FMC2 to take place. Flash Program/Erase Key (FLPEKEY) Base 0x400F.D000 Offset 0x03C Type RO, reset 0x0000.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 PEKEY Type Reset RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 PEKEY RO 0xFFFF Key Value When a value other than all 1s or all 0s, this 16-bit value is used as the "match" for the upper 16-bits of the register FMC and FMC2 keys. 640 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 10: Flash Write Buffer n (FWBn), offset 0x100 - 0x17C These 32 registers hold the contents of the data to be written into the Flash memory on a buffered Flash memory write operation. The offset selects one of the 32-bit registers. Only FWBn registers that have been updated since the preceding buffered Flash memory write operation are written into the Flash memory, so it is not necessary to write the entire bank of registers in order to write 1 or 2 words. The FWBn registers are written into the Flash memory with the FWB0 register corresponding to the address contained in FMA. FWB1 is written to the address FMA+0x4 etc. Note that only data bits that are 0 result in the Flash memory being modified. A data bit that is 1 leaves the content of the Flash memory bit at its previous value. Flash Write Buffer n (FWBn) Base 0x400F.D000 Offset 0x100 - 0x17C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 DATA Type Reset DATA Type Reset Bit/Field Name Type 31:0 DATA RW Reset Description 0x0000.0000 Data Data to be written into the Flash memory. June 18, 2014 641 Texas Instruments-Production Data Internal Memory Register 11: Flash Peripheral Properties (FLASHPP), offset 0xFC0 Flash Peripheral Properties (FLASHPP) Base 0x400F.D000 Offset 0xFC0 Type RO, reset 0xF014.01FF Type Reset 31 30 29 28 reserved PFC FMM DFA 27 26 25 24 RO 0 RO 1 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 23 22 21 reserved 20 19 18 EESS 17 16 MAINSS RO 0 RO 0 RO 0 RO 1 RO 0 RO 1 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 SIZE Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31 reserved RO 0 30 PFC RO 0x1 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Prefetch Buffer Mode Value Description 29 FMM RO 0x1 0 Single set of 2x256-bit buffers used. 1 Two sets of 2x256-bit prefetch buffers are available to use and may be enabled through the FLASHCONF register. Flash Mirror Mode Value Description 28 DFA RO 0x1 0 Mirror Mode not available. 1 Flash Mirror Mode is available to be enabled or disabled by user through FLASHCONF register. DMA Flash Access Note: µDMA can only access flash in Run Mode (not available in low power modes). Value Description 27:23 reserved RO 0 0 DMA cannot be used to access Flash 1 DMA may access the Flash memory range specified by the FLASHDMAST and FLASHDMASZ registers Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 642 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 22:19 EESS RO 0x2 Description EEPROM Sector Size of the physical bank Value Description 0x0 1 KB 0x1 2 KB 0x2 4 KB 0x3 8 KB 0x4-0x7 reserved 18:16 MAINSS RO 0x4 Flash Sector Size of the physical bank Value Description 0x0 1 KB 0x1 2 KB 0x2 4 KB 0x3 8 KB 0x4 16 KB 0x5-0x7 reserved 15:0 SIZE RO 0x1FF Flash Size Indicates the size of the on-chip Flash memory Value Description 0x01FF 1024 KB of Flash June 18, 2014 643 Texas Instruments-Production Data Internal Memory Register 12: SRAM Size (SSIZE), offset 0xFC4 This register indicates the size of the on-chip SRAM. Important: This register should be used to determine the size of the SRAM that is implemented on this microcontroller. SRAM Size (SSIZE) Base 0x400F.D000 Offset 0xFC4 Type RO, reset 0x0000.03FF 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 reserved Type Reset SIZE Type Reset Bit/Field Name Type Reset 31:16 reserved RO 0x0 15:0 SIZE RO 0x3FF Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. SRAM Size Indicates the size of the on-chip SRAM. Value Description 0x03FF 256 KB of SRAM 644 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 13: Flash Configuration Register (FLASHCONF), offset 0xFC8 The FLASHCONF register allows the user to enable or disable various properties of the Flash. The force bits, FBFON and FBFOFF, can be used to test code performance and execution by turning the prefetch buffers on and subsequently forcing them off. Flash Configuration Register (FLASHCONF) Base 0x400F.D000 Offset 0xFC8 Type RW, reset 0x0000.0000 Type Reset 31 30 29 28 27 26 25 reserved FMME SPFE RO 0 RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 24 23 22 21 RO 0 RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 9 8 7 6 5 4 3 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved 20 19 CLRTV 18 17 16 FPFON FPFOFF RW 0 RW 0 2 1 0 RO 0 RO 0 RO 0 reserved reserved Type Reset Bit/Field Name Type Reset 31 reserved RO 0 30 FMME RW 0x0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Flash Mirror Mode Enable Value Description 29 SPFE RW 0x0 0 Flash mirror mode is disabled. 1 Flash mirror mode feature is enabled. Access to the lower banks is translated to upper. Single Prefetch Mode Enable Value Description 28:21 reserved RO 0x000 20 CLRTV RW 0 0 A 4x256-bit prefetch buffer is enabled and used. 1 A single 2x256-bit prefetch buffer is enabled and used. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Clear Valid Tags This is a self-clearing bit. Value Description 19:18 reserved RO 0 0 No effect. 1 Clear valid tags in the prefetch buffer. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 645 Texas Instruments-Production Data Internal Memory Bit/Field Name Type Reset 17 FPFON RW 0 Description Force Prefetch On Value Description 16 FPFOFF RW 0 0 No effect 1 Force prefetch buffers to be enabled. Force Prefetch Off Value Description 15:0 reserved RO 0x0000 0 No effect 1 Force prefetch buffers to be disabled. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 646 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 14: ROM Third-Party Software (ROMSWMAP), offset 0xFCC This register indicates the presence of third-party software in the on-chip ROM. ROMSWMAP enables the ROM apertures that are available. ROM Third-Party Software (ROMSWMAP) Base 0x400F.D000 Offset 0xFCC Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset SW7EN Type Reset RO 0 SW6EN SW5EN SW4EN SW3EN SW2EN SW1EN SW0EN RO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:14 SW7EN RO 0x0 ROM SW Region 7 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved 13:12 SW6EN RO 0x0 ROM SW Region 6 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved 11:10 SW5EN RO 0x0 ROM SW Region 5 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved 9:8 SW4EN RO 0x0 ROM SW Region 4 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved June 18, 2014 647 Texas Instruments-Production Data Internal Memory Bit/Field Name Type Reset 7:6 SW3EN RO 0x0 Description ROM SW Region 3 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved 5:4 SW2EN RO 0x0 ROM SW Region 2 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved 3:2 SW1EN RO 0x0 ROM SW Region 1 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved 1:0 SW0EN RO 0x0 ROM SW Region 0 Availability Value Description 0x0 Software region not available to the core. 0x1 Region available to core 0x2-0x3 reserved 648 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 15: Flash DMA Address Size (FLASHDMASZ), offset 0xFD0 The FLASHDMASZ register contains the area of Flash that the µDMA can access. Note: The µDMA can access Flash in Run Mode only (not available in low power modes). Flash DMA Address Size (FLASHDMASZ) Base 0x400F.D000 Offset 0xFD0 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 reserved Type Reset 16 SIZE RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 SIZE Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:18 reserved RO 0x0000 17:0 SIZE RW 0x0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. µDMA-accessible Memory Size The size of the region addressable by the µDMA. Note that the DFA bit must be set in the FLASHPP register before this value can be programmed. Size of region is defined as 2*(SIZE + 1) KB. June 18, 2014 649 Texas Instruments-Production Data Internal Memory Register 16: Flash DMA Starting Address (FLASHDMAST), offset 0xFD4 The starting address for the Flash region accessible by the µDMA is programmed in the FLASHDMAST register. Note: The µDMA can access Flash in Run Mode only (not available in low power modes). Flash DMA Starting Address (FLASHDMAST) Base 0x400F.D000 Offset 0xFD4 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 reserved Type Reset RO 0 RO 0 15 14 22 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 13 12 11 10 9 8 7 6 ADDR Type Reset RW 0 RW 0 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 ADDR RW 0 reserved RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:29 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 28:11 ADDR RW 0x0 Contains the starting address of the flash region accessible by µDMA if the FLASHPP register DFA bit is set 10:0 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8.5 Description EEPROM Register Descriptions (EEPROM Offset) This section lists and describes the EEPROM registers, in numerical order by address offset. Registers in this section are relative to the EEPROM base address of 0x400A.F000. Note that the EEPROM module clock must be enabled before the registers can be programmed (see page 400). There must be a delay of 3 system clocks after the EEPROM module clock is enabled before any EEPROM module registers are accessed. In addition, after enabling or resetting the EEPROM module, software must wait until the WORKING bit in the EEDONE register is clear before accessing any EEPROM registers. 650 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 17: EEPROM Size Information (EESIZE), offset 0x000 The EESIZE register indicates the number of 16-word blocks and 32-bit words in the EEPROM. EEPROM Size Information (EESIZE) Base 0x400A.F000 Offset 0x000 Type RO, reset 0x0060.0600 31 30 RO 0 RO 0 15 RO 0 29 28 27 26 25 24 23 22 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 RO 0 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset 21 BLKCNT WORDCNT Type Reset Bit/Field Name Type Reset 31:27 reserved RO 0 26:16 BLKCNT RO 0x60 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Number of 16-Word Blocks This value encoded in this field describes the number of 16-word blocks in the EEPROM. 15:0 WORDCNT RO 0x600 Number of 32-Bit Words This value encoded in this field describes the number of 32-bit words in the EEPROM. June 18, 2014 651 Texas Instruments-Production Data Internal Memory Register 18: EEPROM Current Block (EEBLOCK), offset 0x004 The EEBLOCK register is used to select the EEPROM block for subsequent reads, writes, and protection control. The value is a page offset into the EEPROM, such that the first block is 0, then second block is 1, etc. Each block contains 16 words. Attempts to set an invalid block causes the BLOCK field to be configured to 0. To verify that the intended block is being accessed, software can read the BLOCK field after it has been written. An invalid block can be either a non-existent block or a block that has been hidden using the EEHIDE register. Note that block 0 cannot be hidden. EEPROM Current Block (EEBLOCK) Base 0x400A.F000 Offset 0x004 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset BLOCK Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x00000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 BLOCK RW 0x0000 Current Block This field specifies the block in the EEPROM that is selected for subsequent accesses. Once this field is configured, the read-write registers operate against the specified block, using the EEOFFSET register to select the word within the block. Additionally, the protection and unlock registers are used for the selected block. The maximum value that can be written into this register is determined by the block count, as indicated by the EESIZE register. Attempts to write this field larger than the maximum number of blocks or to a locked block causes this field to be configured to 0. 652 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: EEPROM Current Offset (EEOFFSET), offset 0x008 The EEOFFSET register is used to select the EEPROM word to read or write within the block selected by the EEBLOCK register. The value is a word offset into the block. Because accesses to the EERDWRINC register change the offset, software can read the contents of this register to determine the current offset. EEPROM Current Offset (EEOFFSET) Base 0x400A.F000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 OFFSET RW 0x0 OFFSET Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Current Address Offset This value is the current address specified as an offset into the block selected by the EEBLOCK register. Once configured, the read-write registers, EERDRWR and EERDWRINC, operate against that address. The offset is automatically incremented by the EERDWRINC register, with wrap around within the block, which means the offset is incremented from 15 back to 0. June 18, 2014 653 Texas Instruments-Production Data Internal Memory Register 20: EEPROM Read-Write (EERDWR), offset 0x010 The EERDWR register is used to read or write the EEPROM word at the address pointed to by the EEBLOCK and EEOFFSET registers. If the protection or access rules do not permit access, the operation is handled as follows: if reading is not allowed, the value 0xFFFF.FFFF is returned in all cases; if writing is not allowed, the EEDONE register is configured to indicate an error. Note: A read of the EERDWR register during the EEPROM initialization sequence is only valid when the WORKING bit is 0 in EEDONE register: EEPROM Read-Write (EERDWR) Base 0x400A.F000 Offset 0x010 Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - VALUE Type Reset RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 VALUE Type Reset RW - RW - RW - RW - RW - RW - RW - Bit/Field Name Type Reset 31:0 VALUE RW - RW - Description EEPROM Read or Write Data On a read, this field contains the value at the word pointed to by EEOFFSET. On a write, this field contains the data to be stored at the word pointed to by EEOFFSET. For writes, configuring this field starts the write process. If protection and access rules do not permit reads, all 1s are returned. If protection and access rules do not permit writes, the write fails and the EEDONE register indicates failure. 654 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 21: EEPROM Read-Write with Increment (EERDWRINC), offset 0x014 The EERDWRINC register is used to read or write the EEPROM word at the address pointed to by the EEBLOCK and EEOFFSET registers, and then increment the OFFSET field in the EEOFFSET register. If the protection or access rules do not permit access, the operation is handled as follows: if reading is not allowed, the value 0xFFFF.FFFF is returned in all cases; if writing is not allowed, the EEDONE register is configured to indicate an error. In any case, the OFFSET field is incremented. If the last value is reached, OFFSET wraps around to 0 and points to the first word. Note: A read of the EERDWRINC register during the EEPROM initialization sequence is only valid when the WORKING bit is 0 in EEDONE register: EEPROM Read-Write with Increment (EERDWRINC) Base 0x400A.F000 Offset 0x014 Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - VALUE Type Reset RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 VALUE Type Reset RW - RW - RW - RW - RW - RW - RW - Bit/Field Name Type Reset 31:0 VALUE RW - RW - Description EEPROM Read or Write Data with Increment On a read, this field contains the value at the word pointed to by EEOFFSET. On a write, this field contains the data to be stored at the word pointed to by EEOFFSET. For writes, configuring this field starts the write process. If protection and access rules do not permit reads, all 1s are returned. If protection and access rules do not permit writes, the write fails and the EEDONE register indicates failure. Regardless of error, the OFFSET field in the EEOFFSET register is incremented by 1, and the value wraps around if the last word is reached. June 18, 2014 655 Texas Instruments-Production Data Internal Memory Register 22: EEPROM Done Status (EEDONE), offset 0x018 The EEDONE register indicates completion status of a write to the following registers: ■ EERDWR or EERDWRINC register (for writes to the EEPROM memory) ■ EEPROT register (for setting read and protection of the current block) ■ EEPASSn registers (for configuring a password for a block) ■ EEDBGME register (for mass erase of an EEPROM block) This register can indicate if the write ended in an error or not. The EEDONE register can be used in conjunction with the EEINT register to be indicate completion. The register can be EEDONE polled or read after an EEINT register interrupt fires. If any of the bit values in the EEDONE register are 1 after completion, then an error has occurred for that register write. If all of the bits are clear then the writes completed with success. Note: Reads of the following registers during the EEPROM initialization sequence are only valid when the WORKING bit is 0 in EEDONE register: ■ EERDWR or EERDWRINC ■ EEPROT ■ EEPASSn EEPROM Done Status (EEDONE) Base 0x400A.F000 Offset 0x018 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 WRBUSY NOPERM WKCOPY WKERASE reserved WORKING Bit/Field Name Type Reset 31:6 reserved RO 0x0000.0 5 WRBUSY RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Write Busy Value Description 0 No error 1 An attempt to access the EEPROM was made while a write was in progress. 656 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 NOPERM RO 0 Description Write Without Permission Value Description 3 WKCOPY RO 0 0 No error 1 An attempt was made to write without permission. This error can result because the block is locked, the write violates the programmed access protection, or when an attempt is made to write a password when the password has already been written. Working on a Copy Value Description 2 WKERASE RO 0 0 The EEPROM is not copying. 1 A write is in progress and is waiting for the EEPROM to copy to or from the copy buffer. Working on an Erase Value Description 0 The EEPROM is not erasing. 1 A write is in progress and the original block is being erased after being copied. 1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 WORKING RO 0 EEPROM Working Value Description 0 The EEPROM is not working. 1 The EEPROM is performing the requested operation. June 18, 2014 657 Texas Instruments-Production Data Internal Memory Register 23: EEPROM Support Control and Status (EESUPP), offset 0x01C The EESUPP register indicates if internal operations are required because an internal copy buffer must be erased or a programming failure has occurred and the operation must be completed. These conditions are explained below as well as in more detail in the section called “Error During Programming” on page 619. ■ If either PRETRY or ERETRY is set indicating that an operation must be completed, setting the START bit causes the operation to be performed again ■ The PRETRY and ERETRY bits are cleared automatically after the failed operation has been successfully completed. These bits are not changed by reset, so any condition that occurred before a reset is still indicated after a reset. EEPROM Support Control and Status (EESUPP) Base 0x400A.F000 Offset 0x01C Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 PRETRY ERETRY RO 0 Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 PRETRY RO - RO 0 RO 0 RO 0 RO 0 RO 0 RO - RO - reserved RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Programming Must Be Retried Value Description 2 ERETRY RO - 0 Programming has not failed. 1 Programming from a copy in either direction failed to complete. Erase Must Be Retried Value Description 1:0 reserved RO 0 0 Erasing has not failed. 1 Erasing failed to complete. If the failed erase is due to the erase of a main buffer, the copy is performed after the erase completes successfully. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 658 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 24: EEPROM Unlock (EEUNLOCK), offset 0x020 The EEUNLOCK register can be used to unlock the whole EEPROM or a single block using a password. Unlocking is only required if a password is registered using the EEPASSn registers for the block that is selected by the EEBLOCK register. If block 0 has a password, it locks the remaining blocks from any type of access, but uses its own protection mechanism, for example readable, but not writable when locked. In addition, if block 0 has a password, it must be unlocked before unlocking any other block. The EEUNLOCK register is written between 1 and 3 times to form the 32-bit, 64-bit, or 96-bit password registered using the EEPASSn registers. The value used to configure the EEPASS0 register must always be written last. For example, for a 96-bit password, the value used to configure the EEPASS2 register must be written first followed by the EEPASS1 and EEPASS0 register values. The block or the whole EEPROM can be re-locked by writing 0xFFFF.FFFF to this register. In the event that an invalid value is written to this register, the block remains locked. The state of the EEPROM lock can be determined by reading back the EEUNLOCK register. If a multi-word password is set and the number of words written is incorrect, writing 0xFFFF.FFFF to this register reverts the EEPROM lock to the locked state, and the proper unlock sequence can be retried. Note that the internal logic is balanced to prevent any electrical or time-based attack being used to find the correct password or its length. Note: A read of the EEUNLOCK register during the EEPROM initialization sequence is only valid when the WORKING bit is 0 in EEDONE register: EEPROM Unlock (EEUNLOCK) Base 0x400A.F000 Offset 0x020 Type RW, reset 31 30 29 28 27 26 25 24 RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 RW - RW - RW - RW - RW - RW - RW - RW - 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - UNLOCK Type Reset UNLOCK Type Reset Bit/Field Name Type Reset 31:0 UNLOCK RW - Description EEPROM Unlock Value Description 0 The EEPROM is locked. 1 The EEPROM is unlocked. The EEPROM is locked if the block referenced by the EEBLOCK register has a password registered, or if the master block (block 0) has a password. Unlocking is performed by writing the password to this register. The block or the EEPROM stays unlocked until it is locked again or until the next reset. It can be locked again by writing 0xFFFF.FFFF to this register. June 18, 2014 659 Texas Instruments-Production Data Internal Memory Register 25: EEPROM Protection (EEPROT), offset 0x030 The EEPROT register is used to set or read the protection for the current block, as selected by the EEBLOCK register. Protection and access control is used to determine when a block's contents can be read or written. Note: A read of the EEPROT register during the EEPROM initialization sequence is only valid when the WORKING bit is 0 in EEDONE register: EEPROM Protection (EEPROT) Base 0x400A.F000 Offset 0x030 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 ACC RO 0 Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 ACC RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 PROT RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Access Control Value Description 0 Both user and supervisor code may access this block of the EEPROM. 1 Only supervisor code may access this block of the EEPROM. μDMA and Debug are also prevented from accessing the EEPROM. If this bit is set for block 0, then the whole EEPROM may only be accessed by supervisor code. 660 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2:0 PROT RW 0x0 Description Protection Control The Protection bits control what context is needed for reading and writing the block selected by the EEBLOCK register, or if block 0 is selected, all blocks. The following values are allowed: Value Description 0x0 This setting is the default. Without password: the block is not protected and is readable and writable at any time. With password: the block is readable, but only writable when unlocked. 0x1 With password: the block is readable or writable only when unlocked. This value has no meaning when there is no password. 0x2 Without password: the block is readable, not writable. With password: the block is readable only when unlocked, but is not writable under any conditions. 0x3 Reserved June 18, 2014 661 Texas Instruments-Production Data Internal Memory Register 26: EEPROM Password (EEPASS0), offset 0x034 Register 27: EEPROM Password (EEPASS1), offset 0x038 Register 28: EEPROM Password (EEPASS2), offset 0x03C The EEPASSn registers are used to configure a password for a block. A password may only be set once and cannot be changed. The password may be 32-bits, 64-bits, or 96-bits. Each word of the password can be any 32-bit value other than 0xFFFF.FFFF (all 1s). To set a password, the EEPASS0 register is written to with a value other than 0xFFFF.FFFF. When the write completes, as indicated in the EEDONE register, the application may choose to write to the EEPASS1 register with a value other than 0xFFFF.FFFF. When that write completes, the application may choose to write to the EEPASS2 register with a value other than 0xFFFF.FFFF to create a 96-bit password. The registers do not have to be written consecutively, and the EEPASS1 and EEPASS2 registers may be written at a later date. Based on whether 1, 2, or all 3 registers have been written, the unlock code also requires the same number of words to unlock. Note: Once the password is written, the block is not actually locked until either a reset occurs or 0xFFFF.FFFF is written to EEUNLOCK. Note: A read of the EEPASSn register during the EEPROM initialization sequence is only valid when the WORKING bit is 0 in EEDONE register: EEPROM Password (EEPASSn) Base 0x400A.F000 Offset 0x034 Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - PASS Type Reset PASS Type Reset Bit/Field Name Type Reset 31:0 PASS RW - Description Password This register reads as 0x1 if a password is registered for this block and 0x0 if no password is registered. A write to this register if it reads as 0x0 sets the password. If an attempt is made to write to this register when it reads as 0x1, the write is ignored and the NOPERM bit in the EEDONE register is set. 662 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 29: EEPROM Interrupt (EEINT), offset 0x040 The EEINT register is used to control whether an interrupt should be generated when a write to EEPROM completes as indicated by the EEDONE register value changing from 0x1 to any other value. If the INT bit in this register is set, the ERIS bit in the Flash Controller Raw Interrupt Status (FCRIS) register is set whenever the EEDONE register value changes from 0x1 as the Flash memory and the EEPROM share an interrupt vector. EEPROM Interrupt (EEINT) Base 0x400A.F000 Offset 0x040 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 INT RW 0 RO 0 INT Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Interrupt Enable Value Description 0 No interrupt is generated. 1 An interrupt is generated when the EEDONE register transitions from 1 to 0 or an error occurs. The EEDONE register provides status after a write to an offset location as well as a write to the password and protection bits. June 18, 2014 663 Texas Instruments-Production Data Internal Memory Register 30: EEPROM Block Hide 0 (EEHIDE0), offset 0x050 The EEHIDE0 register is used to hide one or more blocks other than EEPROM block 0. Bits 1 through 31 of this register correspond to EEPROM blocks 1 through 31. Once hidden, the block is not accessible until the next reset. This model allows initialization code to have access to data which is not visible to the rest of the application. This register also provides for additional security in that there is no password to search for in the code or data. EEPROM Block Hide 0 (EEHIDE0) Base 0x400A.F000 Offset 0x050 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Hn Type Reset Hn Type Reset reserved Bit/Field Name Type Reset Description 31:1 Hn RW 0x0000.000 Hide Block RO 0 Value Description 0 The corresponding block is not hidden. 1 The block number that corresponds to the bit number is hidden. A hidden block cannot be accessed, and the OFFSET value in the EEBLOCK register cannot be set to that block number. If an attempt is made to configure the OFFSET field to a hidden block, the EEBLOCK register is cleared. Any attempt to clear a bit in this register that is set is ignored. 0 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 664 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 31: EEPROM Block Hide 1 (EEHIDE1), offset 0x054 Register 32: EEPROM Block Hide 2 (EEHIDE2), offset 0x058 The EEHIDE register is used to hide one or more blocks. Bits 0 through 31 of the EEHIDE1 register correspond to EEPROM blocks 32 through 63. Bits 0 through 31 of the EEHIDE2 register correspond to EEPROM blocks 64 through 95. Once hidden, the block is not accessible until the next reset. This model allows initialization code to have access to data which is not visible to the rest of the application. This register also provides for additional security in that there is no password to search for in the code or data. EEPROM Block Hide n (EEHIDEn) Base 0x400A.F000 Offset 0x054 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Hn Type Reset Hn Type Reset Bit/Field Name Type Reset Description 31:0 Hn RW 0x0000.000 Hide Block Value Description 0 The corresponding block is not hidden. 1 The block number that corresponds to the bit number is hidden. A hidden block cannot be accessed, and the OFFSET value in the EEBLOCK register cannot be set to that block number. If an attempt is made to configure the OFFSET field to a hidden block, the EEBLOCK register is cleared. Any attempt to clear a bit in this register that is set is ignored. June 18, 2014 665 Texas Instruments-Production Data Internal Memory Register 33: EEPROM Debug Mass Erase (EEDBGME), offset 0x080 The EEDBGME register is used to mass erase the EEPROM block back to its default state from the factory. This register is intended to be used only for debug and test purposes, not in production environments. The erase takes place in such a way as to be secure. It first erases all data and then erases the protection mechanism. This register can only be written from supervisor mode by the core, and can also be written by the Tiva™ C Series debug controller when enabled. A key is used to avoid accidental use of this mechanism. Note that if a power down takes place while erasing, the mechanism should be used again to complete the operation. Powering off prematurely does not expose secured data. To start a mass erase, the whole register must be written as 0xE37B.0001. The register reads back as 0x1 until the erase is fully completed at which time it reads as 0x0. The EEDONE register is set to 0x1 when the erase is started and changes to 0x0 or an error when the mass erase is complete. EEPROM Debug Mass Erase (EEDBGME) Base 0x400A.F000 Offset 0x080 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 8 7 6 5 4 3 2 1 KEY Type Reset WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 15 14 13 12 11 10 9 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 0 ME RO 0 Bit/Field Name Type Reset Description 31:16 KEY WO 0x0000 Erase Key RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 This field must be written with 0xE37B for the ME field to be effective. 15:1 reserved RO 0x000 0 ME RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Mass Erase Value Description 0 No action. 1 When written as a 1, the EEPROM is mass erased. This bit continues to read as 1 until the EEPROM is fully erased. 666 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 34: EEPROM Peripheral Properties (EEPROMPP), offset 0xFC0 The EEPROMPP register indicates the size of the EEPROM for this part. EEPROM Peripheral Properties (EEPROMPP) Base 0x400A.F000 Offset 0xFC0 Type RO, reset 0x0000.01FF 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 reserved Type Reset SIZE Type Reset Bit/Field Name Type Reset 31:16 reserved RO 0x0 15:0 SIZE RO 0x1FF Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. EEPROM Size Indicates the size of the on-chip EEPROM. Any values not shown are reserved. Value Description 0x0000 64 bytes of EEPROM 0x0001 128 bytes of EEPROM 0x0003 256 bytes of EEPROM 0x0007 512 bytes of EEPROM 0x000F 1 KB of EEPROM 0x001F 2 KB of EEPROM 0x003F 3 KB of EEPROM 0x007F 4 KB of EEPROM 0x00FF 5 KB of EEPROM 0x01FF 6 KB of EEPROM 8.6 Memory Register Descriptions (System Control Offset) The remainder of this section lists and describes the registers that reside in the System Control address space, in numerical order by address offset. Registers in this section are relative to the System Control base address of 0x400F.E000. June 18, 2014 667 Texas Instruments-Production Data Internal Memory Register 35: Reset Vector Pointer (RVP), offset 0x0D4 The Reset Vector Pointer (RVP) register contains the address of the reset vector of the software module that is to be executed after boot loader execution. The RVP register is initialized by a power-on reset. Reset Vector Pointer (RVP) Base 0x400F.E000 Offset 0x0D4 Type RO, reset 0x0101.FFF0 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 RV Type Reset RV Type Reset Bit/Field Name Type 31:0 RV RO Reset Description 0x0101.FFF0 Reset Vector Pointer Address 668 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 36: Flash Memory Protection Read Enable 0 (FMPRE0), offset 0x200 Register 37: Flash Memory Protection Read Enable 1 (FMPRE1), offset 0x204 Register 38: Flash Memory Protection Read Enable 2 (FMPRE2), offset 0x208 Register 39: Flash Memory Protection Read Enable 3 (FMPRE3), offset 0x20C Register 40: Flash Memory Protection Read Enable 4 (FMPRE4), offset 0x210 Register 41: Flash Memory Protection Read Enable 5 (FMPRE5), offset 0x214 Register 42: Flash Memory Protection Read Enable 6 (FMPRE6), offset 0x218 Register 43: Flash Memory Protection Read Enable 7 (FMPRE7), offset 0x21C Register 44: Flash Memory Protection Read Enable 8 (FMPRE8), offset 0x220 Register 45: Flash Memory Protection Read Enable 9 (FMPRE9), offset 0x224 Register 46: Flash Memory Protection Read Enable 10 (FMPRE10), offset 0x228 Register 47: Flash Memory Protection Read Enable 11 (FMPRE11), offset 0x22C Register 48: Flash Memory Protection Read Enable 12 (FMPRE12), offset 0x230 Register 49: Flash Memory Protection Read Enable 13 (FMPRE13), offset 0x234 Register 50: Flash Memory Protection Read Enable 14 (FMPRE14), offset 0x238 Register 51: Flash Memory Protection Read Enable 15 (FMPRE15), offset 0x23C Note: The FMPRE0 register is aliased for backwards compatibility. Note: Offset is relative to System Control base address of 0x400F.E000. This register stores the read-only protection bits for each 2-KB flash block (FMPPEn stores the execute-only bits). Note that for protecting sectors, eight bits need to be cleared to create a 16-KB read-protected sector. This register is loaded during the power-on reset sequence. The factory settings for the FMPREn and FMPPEn registers are a value of 1 for all implemented banks. This achieves a policy of open access and programmability. The register bits may be changed by writing the specific register bit. However, this register is RW0; the user can only change the protection bit from a 1 to a 0 (and may NOT change a 0 to a 1). The changes are not permanent until the register is committed (saved), at which point the bit change is permanent. If a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. The reset value shown only applies to power-on reset; any other type of reset does not affect this register. Once committed, the only way to restore the factory default value of this register is to perform the "Recover Locked Device" sequence detailed in the JTAG chapter. Each FMPREn register controls a 64K block. For additional information, see “Protected Flash Memory Registers” on page 609. June 18, 2014 669 Texas Instruments-Production Data Internal Memory ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ FMPRE0: 0 to 64 KB FMPRE1: 65 to 128 KB FMPRE2: 129 to 192 KB FMPRE3: 193 to 256 KB FMPRE4: 257 to 320 KB FMPRE5: 321 to 384 KB FMPRE6: 385 to 448 KB FMPRE7: 449 to 512 KB FMPRE8: 513 to 576 KB FMPRE9: 577 to 640 KB FMPRE10: 641 to 704 KB FMPRE11: 705 to 768 KB FMPRE12: 769 to 832 KB FMPRE13: 833 to 896 KB FMPRE14: 897 to 960 KB FMPRE15: 961 to 1024 KB Flash Memory Protection Read Enable n (FMPREn) Base 0x400F.E000 Offset 0x200 Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 READ_ENABLE Type Reset READ_ENABLE Type Reset Bit/Field Name Type 31:0 READ_ENABLE RW Reset RW 1 RW 1 Description 0xFFFF.FFFF Flash Read Enable Each bit configures a 2-KB flash block to be read only. Note that for read-protection of sectors, eight bits need to be cleared to create a 16-KB read-protected sector. The policies may be combined as shown in the table "Flash Protection Policy Combinations". 670 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 52: Flash Memory Protection Program Enable 0 (FMPPE0), offset 0x400 Register 53: Flash Memory Protection Program Enable 1 (FMPPE1), offset 0x404 Register 54: Flash Memory Protection Program Enable 2 (FMPPE2), offset 0x408 Register 55: Flash Memory Protection Program Enable 3 (FMPPE3), offset 0x40C Register 56: Flash Memory Protection Program Enable 4 (FMPPE4), offset 0x410 Register 57: Flash Memory Protection Program Enable 5 (FMPPE5), offset 0x414 Register 58: Flash Memory Protection Program Enable 6 (FMPPE6), offset 0x418 Register 59: Flash Memory Protection Program Enable 7 (FMPPE7), offset 0x41C Register 60: Flash Memory Protection Program Enable 8 (FMPPE8), offset 0x420 Register 61: Flash Memory Protection Program Enable 9 (FMPPE9), offset 0x424 Register 62: Flash Memory Protection Program Enable 10 (FMPPE10), offset 0x428 Register 63: Flash Memory Protection Program Enable 11 (FMPPE11), offset 0x42C Register 64: Flash Memory Protection Program Enable 12 (FMPPE12), offset 0x430 Register 65: Flash Memory Protection Program Enable 13 (FMPPE13), offset 0x434 Register 66: Flash Memory Protection Program Enable 14 (FMPPE14), offset 0x438 Register 67: Flash Memory Protection Program Enable 15 (FMPPE15), offset 0x43C Note: The FMPPE0 register is aliased for backwards compatibility. Note: Offset is relative to System Control base address of 0x400FE000. This register stores the execute-only protection bits for each 2-KB flash block (FMPREn stores the read-only protection bits). Since the memory is two-way interleaved and each bank individually is an 8-KB sector, read-only protection must occur across a block size of 16-KB. No smaller block size June 18, 2014 671 Texas Instruments-Production Data Internal Memory is supported. Note that the Flash Memory Protection Read (FMPREn) registers do allow read-protection of a block as small as 2 KB, unlike the FMPPEn registers. Thus, in order to execute-only protect a 16-KB block, a user must program the entire eight bits of the byte to the same value. For example, to protect the first 16-KB block, bits [7:0] of the FMPPE0 register need to be cleared to all 0s. This register is loaded during the power-on reset sequence. The factory settings for the FMPREn and FMPPEn registers are a value of 1 for all implemented banks. This achieves a policy of open access and programmability. This register is RW0; the user can only change the protection byte from all 1s to all 0s (and may NOT change from all 0 to all 1). The changes are not permanent until the register is committed (saved), at which point the byte change is permanent. If a byte is changed from all 1s to all 0s and not committed, it may be restored by executing a power-on reset sequence. The reset value shown only applies to power-on reset; any other type of reset does not affect this register. Once committed, the only way to restore the factory default value of this register is to perform the "Recover Locked Device" sequence detailed in the JTAG chapter. For additional information, see “Protected Flash Memory Registers” on page 609. Each FMPPEn register controls a 64K block. For additional information, see “Protected Flash Memory Registers” on page 609. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ FMPPE0: 0 to 64 KB FMPPE1: 65 to 128 KB FMPPE2: 129 to 192 KB FMPPE3: 193 to 256 KB FMPPE4: 257 to 320 KB FMPPE5: 321 to 384 KB FMPPE6: 385 to 448 KB FMPPE7: 449 to 512 KB FMPPE8: 513 to 576 KB FMPPE9: 577 to 640 KB FMPPE10: 641 to 704 KB FMPPE11: 705 to 768 KB FMPPE12: 769 to 832 KB FMPPE13: 833 to 896 KB FMPPE14: 897 to 960 KB FMPPE15: 961 to 1024 KB Flash Memory Protection Program Enable n (FMPPEn) Base 0x400F.E000 Offset 0x400 Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 PROG_ENABLE Type Reset PROG_ENABLE Type Reset RW 1 RW 1 672 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type 31:0 PROG_ENABLE RW Reset Description 0xFFFF.FFFF Flash Programming Enable Every eighth bit programs an 16-KB flash sector to be execute only. The policies may be combined as shown in Table 8-2 on page 610. June 18, 2014 673 Texas Instruments-Production Data Internal Memory Register 68: Boot Configuration (BOOTCFG), offset 0x1D0 Note: Offset is relative to System Control base address of 0x400F.E000. Note: The Boot Configuration (BOOTCFG) register requires a POR before the committed changes take effect. This register is not written directly, but instead uses the FMD register as explained in “Non-Volatile Register Programming-- Flash Memory Resident Registers” on page 613. When this register is committed, the new value cannot be read back until after the power cycle. This register provides configuration of a GPIO pin to enable the ROM Boot Loader as well as a write-once mechanism to disable external debugger access to the device. At reset, the user has the opportunity to direct the core to execute the ROM Boot Loader or the application in Flash memory by using any GPIO signal from Ports A through H as configured by the bits in this register. At reset, the following sequence is performed: 1. The BOOTCFG register is read. If the EN bit is clear, the ROM Boot Loader is executed. 2. In the ROM Boot Loader, the status of the specified GPIO pin is compared with the specified polarity. If the status matches the specified polarity, the ROM is mapped to address 0x0000.0000 and execution continues out of the ROM Boot Loader. 3. If the EN bit is set or the status doesn't match the specified polarity, the data at address 0x0000.0004 is read, and if the data at this address is 0xFFFF.FFFF, the ROM is mapped to address 0x0000.0000 and execution continues out of the ROM Boot Loader. 4. If there is data at address 0x0000.0004 that is not 0xFFFF.FFFF, the stack pointer (SP) is loaded from Flash memory at address 0x0000.0000 and the program counter (PC) is loaded from address 0x0000.0004. The user application begins executing. The DBG0 bit is cleared by the factory and the DBG1 bit is set, which enables external debuggers. Clearing the DBG1 bit disables any external debugger access to the device, starting with the next power-up cycle of the device. The NW bit indicates that bits in the register can be changed from 1 to 0. By committing the register values using the COMT bit in the FMC register, the register contents become non-volatile and are therefore retained following power cycling. Prior to being committed, bits can only be changed from 1 to 0. The reset value shown only applies to power-on reset when the register is not yet committed; any other type of reset does not affect this register. Once committed, the register retains its value through power-on reset. Once committed, the only way to restore the factory default value of this register is to perform the sequence detailed in “Recovering a "Locked" Microcontroller” on page 213. Boot Configuration (BOOTCFG) Base 0x400F.E000 Offset 0x1D0 Type RO, reset 0xFFFF.FFFE 31 30 29 28 27 26 25 24 NW Type Reset RO 1 15 RO 1 RO 1 RO 1 14 13 12 PORT Type Reset RO 1 23 22 21 20 19 18 17 16 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 6 5 4 3 2 reserved RO 1 RO 1 RO 1 11 10 PIN RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 7 9 8 POL EN RO 1 RO 1 reserved RO 1 RO 1 674 KEY RO 1 RO 1 reserved RO 1 RO 1 1 0 DBG1 DBG0 RO 1 RO 0 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset Description 31 NW RO 1 Not Written When set, this bit indicates that the values in this register can be changed from 1 to 0. When clear, this bit specifies that the contents of this register cannot be changed. 30:16 reserved RO 0xFFFF 15:13 PORT RO 0x7 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Boot GPIO Port This field selects the port of the GPIO port pin that enables the ROM boot loader at reset. Note: The selected port can be reprogrammed for a different function after reset. Value Description 12:10 PIN RO 0x7 0x0 Port A 0x1 Port B 0x2 Port C 0x3 Port D 0x4 Port E 0x5 Port F 0x6 Port G 0x7 Port H Boot GPIO Pin This field selects the pin number of the GPIO port pin that enables the ROM boot loader at reset. Value Description 9 POL RO 1 0x0 Pin 0 0x1 Pin 1 0x2 Pin 2 0x3 Pin 3 0x4 Pin 4 0x5 Pin 5 0x6 Pin 6 0x7 Pin 7 Boot GPIO Polarity When set, this bit selects a high level for the GPIO port pin to enable the ROM boot loader at reset. When clear, this bit selects a low level for the GPIO port pin. June 18, 2014 675 Texas Instruments-Production Data Internal Memory Bit/Field Name Type Reset 8 EN RO 1 Description Boot GPIO Enable Clearing this bit enables the use of a GPIO pin to enable the ROM Boot Loader at reset. When this bit is set, the contents of address 0x0000.0004 are checked to see if the Flash memory has been programmed. If the contents are not 0xFFFF.FFFF, the core executes out of Flash memory. If the Flash has not been programmed, the core executes out of ROM. 7:5 reserved RO 0x7 4 KEY RO 1 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. KEY Select This bit chooses between using the value 0xA442 or the PEKEY value in the FLPEKEY register as the WRKEY value in the FMC/FMC2 register. Value Description 3:2 reserved RO 0x3 1 DBG1 RO 1 0 The PEKEY value in the FLPEKEY register is committed by user and used as the WRKEY in the FMC/FMC2 register. Writes to FMC/FMC2 register with a 0xA442 key are ignored. 1 0xA442 is used as key Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Debug Control 1 The DBG1 bit must be 1 and DBG0 must be 0 for debug to be available. 0 DBG0 RO 0 Debug Control 0 The DBG1 bit must be 1 and DBG0 must be 0 for debug to be available. 676 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 69: User Register 0 (USER_REG0), offset 0x1E0 Register 70: User Register 1 (USER_REG1), offset 0x1E4 Register 71: User Register 2 (USER_REG2), offset 0x1E8 Register 72: User Register 3 (USER_REG3), offset 0x1EC Note: Offset is relative to System Control base address of 0x400F.E000. These registers each provide 32 bits of user-defined data that is non-volatile. Bits can only be changed from 1 to 0. The reset value shown only applies to power-on reset when the register is not yet committed; any other type of reset does not affect this register. Once committed, the register retains its value through power-on reset. The only way to restore the factory default value of this register is to perform the "Recover Locked Device" sequence detailed in the JTAG section. User Register n (USER_REGn) Base 0x400F.E000 Offset 0x1E0 Type W0, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 DATA Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 DATA Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 Bit/Field Name Type 31:0 DATA RW RW 1 Reset RW 1 Description 0xFFFF.FFFF User Data Contains the user data value. This field is initialized to all 1s and once committed, retains its value through power-on reset. June 18, 2014 677 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) 9 Micro Direct Memory Access (μDMA) The TM4C1294NCPDT microcontroller includes a Direct Memory Access (DMA) controller, known as micro-DMA (μDMA). The μDMA controller provides a way to offload data transfer tasks from the Cortex™-M4F processor, allowing for more efficient use of the processor and the available bus bandwidth. The μDMA controller can perform transfers between memory and peripherals. It has dedicated channels for each supported on-chip module and can be programmed to automatically perform transfers between peripherals and memory as the peripheral is ready to transfer more data. The μDMA controller provides the following features: ® ® ■ ARM PrimeCell 32-channel configurable µDMA controller ■ Support for memory-to-memory, memory-to-peripheral, and peripheral-to-memory in multiple transfer modes – Basic for simple transfer scenarios – Ping-pong for continuous data flow – Scatter-gather for a programmable list of up to 256 arbitrary transfers initiated from a single request ■ Highly flexible and configurable channel operation – Independently configured and operated channels – Dedicated channels for supported on-chip modules – Flexible channel assignments – One channel each for receive and transmit path for bidirectional modules – Dedicated channel for software-initiated transfers – Per-channel configurable priority scheme – Optional software-initiated requests for any channel ■ Two levels of priority ■ Design optimizations for improved bus access performance between µDMA controller and the processor core – µDMA controller access is subordinate to core access – RAM striping – Peripheral bus segmentation ■ Data sizes of 8, 16, and 32 bits ■ Transfer size is programmable in binary steps from 1 to 1024 ■ Source and destination address increment size of byte, half-word, word, or no increment 678 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Maskable peripheral requests ■ Interrupt on transfer completion, with a separate interrupt per channel 9.1 Block Diagram Figure 9-1. μDMA Block Diagram uDMA Controller DMA error System Memory CH Control Table IRQ Nested Vectored Interrupt Controller (NVIC) IRQ dma_req General Peripheral N dma_sreq Registers dma_done dma_req General Peripheral N dma_sreq Registers dma_done DMASTAT DMACFG DMACTLBASE DMAALTBASE DMAWAITSTAT DMASWREQ DMAUSEBURSTSET DMAUSEBURSTCLR DMAREQMASKSET DMAREQMASKCLR DMAENASET DMAENACLR DMAALTSET DMAALTCLR DMAPRIOSET DMAPRIOCLR DMAERRCLR DMACHASGN DMACHMAPn DMASRCENDP DMADSTENDP DMACHCTRL • • • DMASRCENDP DMADSTENDP DMACHCTRL Transfer Buffers Used by µDMA ARM Cortex-M4F 9.2 Functional Description The μDMA controller is a flexible and highly configurable DMA controller designed to work efficiently with the microcontroller's Cortex-M4F processor core. It supports multiple data sizes and address increment schemes, multiple levels of priority among DMA channels, and several transfer modes to allow for sophisticated programmed data transfers. The μDMA controller's usage of the bus is always subordinate to the processor core, so it never holds up a bus transaction by the processor. Because the μDMA controller is only using otherwise-idle bus cycles, the data transfer bandwidth it provides is essentially free, with no impact on the rest of the system. The bus architecture has been optimized to greatly enhance the ability of the processor core and the μDMA controller to efficiently share the on-chip bus, thus improving performance. The optimizations include RAM striping and peripheral bus segmentation, which in many cases allow both the processor core and the μDMA controller to access the bus and perform simultaneous data transfers. Each peripheral function that is supported has a dedicated channel on the μDMA controller that can be configured independently. The μDMA controller implements a unique configuration method using channel control structures that are maintained in system memory by the processor. While simple transfer modes are supported, it is also possible to build up sophisticated "task" lists in memory that allow the μDMA controller to perform arbitrary-sized transfers to and from arbitrary locations as part of a single transfer request. The μDMA controller also supports the use of ping-pong buffering to accommodate constant streaming of data to or from a peripheral. Each channel also has a configurable arbitration size. The arbitration size is the number of items that are transferred in a burst before the μDMA controller re-arbitrates for channel priority. Using June 18, 2014 679 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) the arbitration size, it is possible to control exactly how many items are transferred to or from a peripheral each time it makes a μDMA service request. 9.2.1 Channel Assignments Each DMA channel has up to nine possible assignments which are selected using the DMA Channel Map Select n (DMACHMAPn) registers with 4-bit assignment fields for each µDMA channel. Table 9-1 on page 680 shows the µDMA channel mapping. The Enc. column shows the encoding for the respective DMACHMAPn bit field. Encodings 0x9-0xF are reserved. To support legacy software which uses the DMA Channel Assignment (DMACHASGN) register, Enc. 0 is equivalent to a DMACHASGN bit being clear, and Enc. 1 is equivalent to a DMACHASGN bit being set. If the DMACHASGN register is read, bit fields return 0 if the corresponding DMACHMAPn register field value are equal to 0, otherwise they return 1 if the corresponding DMACHMAPn register field values are not equal to 0. The Type indication in the table indicates if a particular peripheral uses a single request (S), burst request (B) or either (SB). Note: Channels or encodings marked as reserved cannot be used for µDMA transfers. Channels designated in the table as only "Software" are dedicated software channels. When only one software request is required in an application, dedicated software channels can be used. If multiple software requests in code are required, then peripheral channel software requests should be used for proper µDMA completion acknowledgement. Table 9-1. μDMA Channel Assignments - GPTimer 3A B Reserved GPTimer 3B B Reserved B Reserved GPTimer 4B B Reserved Reserved - - - Reserved - Peripheral 7 Type SB Reserved GPTimer 4A Peripheral Type UART2 TX - Type SB Reserved Peripheral 6 Peripheral I2C0 RX SB Reserved - Reserved - I2C0 TX SB Reserved Reserved - Reserved - I2C1RX SB Reserved - Software S Reserved - Reserved - I2C1 TX SB Reserved - - Reserved - - Reserved - - Reserved - - Reserved - - Reserved - B B Reserved - GPIO A B Reserved - Software B I2C2 RX SB Reserved 5 Reserved - GPTimer 2B B Reserved - GPIO B B Reserved - Software B I2C2 TX GPTimer 2A B UART5 RX SB GPIO C GPTimer 2B B UART5 TX SB GPIO D - Reserved B GPTimer 2A 7 Reserved - B - - Peripheral B 4 Reserved 6 Reserved 8 Type 3 Reserved - UART2 RX Peripheral 5 Type 2 Reserved - Peripheral 4 Type 1 Reserved - Peripheral 3 Type 0 Reserved 2 Type Peripheral 1 Type Channel Encoding 0 B SB Reserved B 8 UART0 RX SB UART1 RX SB Reserved 9 UART0 TX SB UART1 TX SB Reserved 10 SSI0 RX SB SSI1 RX SB UART6 RX B I2C0 RX SB Software B Reserved - Reserved - Reserved - B B I2C0 TX SB Reserved - Reserved - Reserved - Reserved - - Reserved - Reserved - Reserved - - Reserved - Reserved - Reserved - - Reserved - GPTimer 6A B Reserved - B - GPTimer 5A B I2C1RX GPTimer 5B B I2C1 TX SB Reserved SB Reserved B SB Reserved B - I2C2 RX SB Reserved B 680 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 9-1. μDMA Channel Assignments (continued) SB Reserved - Reserved 8 - GPTimer 6B B Reserved - B Peripheral Type I2C2 TX 7 Peripheral Type - 6 Peripheral Type 5 Peripheral Type SB Reserved 4 Peripheral Type 11 SSI0 TX SB SSI1 TX SB UART6 TX 3 Peripheral Type 2 Peripheral Type 1 Peripheral Type 0 Peripheral Type Channel Encoding 12 Reserved - UART2 RX SB SSI2 RX SB Reserved - GPIO K B Software B Reserved - GPTimer 7A B Reserved - 13 Reserved - UART2 TX SB SSI2 TX SB Reserved - GPIO L B Software B Reserved - GPTimer 7B B Reserved - 14 ADC0 SS0 SB GPTimer 2A B SSI3 RX SB GPIO E B GPIO M B Software B Reserved - Reserved - Reserved - 15 ADC0 SS1 SB GPTimer 2B B SSI3 TX SB GPIO F B GPIO N B Software B Reserved - Reserved - Reserved - 16 ADC0 SS2 SB Reserved - UART3 RX SB Reserved - GPIO P B Reserved - Reserved - Reserved - Reserved - 17 ADC0 SS3 SB Reserved - UART3 TX SB Reserved - Reserved - Reserved - Reserved - Reserved - Reserved - B I2C3 RX SB Reserved - Reserved - Reserved - Reserved - - Reserved - Reserved - Reserved - - Reserved - Reserved - - Reserved - Reserved - - Reserved - I2C8 RX B 18 GPTimer 0A B GPTimer 1A B UART4 RX SB GPIO B 19 GPTimer 0B B GPTimer 1B B UART4 TX SB GPIO G 20 GPTimer 1A B EPI 0 RX B UART7 RX Software SB GPIO H B I2C4 RX SB Software B Reserved 21 GPTimer 1B B EPI 0 TX SB GPIO J B I2C4 TX Software 22 UART1 RX SB Software 23 UART1 TX SB Software B UART7 TX B Reserved B B I2C3 TX SB Reserved B B SB Software B Reserved B - Software B I2C5 RX SB Software B Reserved B B Reserved - Software B I2C5 TX SB Reserved - Reserved - Reserved - I2C8 TX B B Reserved - Reserved - Reserved - I2C9 RX B B 24 SSI1 RX SB ADC1 SS0 SB Reserved - Reserved - GPIO Q 25 SSI1 TX SB ADC1 SS1 SB Reserved - Reserved - Software Reserved - Reserved - Reserved - I2C9 TX B 26 Software B ADC1 SS2 SB Reserved - Reserved - Software Reserved - Reserved - Reserved - I2C6 RX B 27 Software B ADC1 SS3 SB Reserved - Reserved - Reserved - Reserved - Software B Reserved - I2C6 TX B 28 Reserved - Reserved - Reserved - Reserved - Reserved - Reserved - I2C7 RX B Reserved I2C7 TX B - Reserved - Reserved - 29 Reserved - Reserved - Reserved - Reserved - Reserved - Reserved - Reserved - 30 Software B Software B Reserved - Software B Reserved - Reserved - Reserved - EPI0 RX B Software B 31 Reserved - - - Reserved B Reserved - Reserved - Reserved - EPI0 TX B Reserved 9.2.2 Reserved Reserved - Priority The μDMA controller assigns priority to each channel based on the channel number and the priority level bit for the channel. Channel number 0 has the highest priority and as the channel number increases, the priority of a channel decreases. Each channel has a priority level bit to provide two June 18, 2014 681 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) levels of priority: default priority and high priority. If the priority level bit is set, then that channel has higher priority than all other channels at default priority. If multiple channels are set for high priority, then the channel number is used to determine relative priority among all the high priority channels. The priority bit for a channel can be set using the DMA Channel Priority Set (DMAPRIOSET) register and cleared with the DMA Channel Priority Clear (DMAPRIOCLR) register. Note: 9.2.3 If one peripheral is mapped to two different channels, then the application should either use the default mapping for that peripheral or change the default mapping to another source. For example, if UART1 channels 8 and 9 are enabled for use, then even if channels 22 and 23 are disabled, they must be mapped to software or another peripheral (if available). Arbitration Size When a μDMA channel requests a transfer, the μDMA controller arbitrates among all the channels making a request and services the μDMA channel with the highest priority. Once a transfer begins, it continues for a selectable number of transfers before rearbitrating among the requesting channels again. The arbitration size can be configured for each channel, ranging from 1 to 1024 item transfers. After the μDMA controller transfers the number of items specified by the arbitration size, it then checks among all the channels making a request and services the channel with the highest priority. If a lower priority μDMA channel uses a large arbitration size, the latency for higher priority channels is increased because the μDMA controller completes the lower priority burst before checking for higher priority requests. Therefore, lower priority channels should not use a large arbitration size for best response on high priority channels. The arbitration size can also be thought of as a burst size. It is the maximum number of items that are transferred at any one time in a burst. Here, the term arbitration refers to determination of μDMA channel priority, not arbitration for the bus. When the μDMA controller arbitrates for the bus, the processor always takes priority. Furthermore, the μDMA controller is held off whenever the processor must perform a bus transaction on the same bus, even in the middle of a burst transfer. 9.2.4 Request Types The μDMA controller responds to two types of requests from a peripheral: single or burst. Each peripheral may support either or both types of requests. A single request means that the peripheral is ready to transfer one item, while a burst request means that the peripheral is ready to transfer multiple items. The μDMA controller responds differently depending on whether the peripheral is making a single request or a burst request. If both are asserted, and the μDMA channel has been set up for a burst transfer, then the burst request takes precedence. See Table 9-2 on page 682, which shows how each peripheral supports the two request types. Table 9-2. Request Type Support Peripheral Event that generates Single Request Event that generates Burst Request ADC FIFO not empty FIFO half full EPI WFIFO None WFIFO Level (configurable) EPI NBRFIFO None NBRFIFO Level (configurable) General-Purpose Timer None Trigger event GPIO None Trigger event I2C TX TX Buffer Not Full TX FIFO Level (configurable) I2C RX RX Buffer Not Empty RX FIFO Level (configurable) TX FIFO Not Full TX FIFO Level (fixed at 4) SSI TX 682 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 9-2. Request Type Support (continued) 9.2.4.1 Peripheral Event that generates Single Request Event that generates Burst Request SSI RX RX FIFO Not Empty RX FIFO Level (fixed at 4) UART TX TX FIFO Not Full TX FIFO Level (configurable) UART RX RX FIFO Not Empty RX FIFO Level (configurable) Single Request When a single request is detected, and not a burst request, the μDMA controller transfers one item and then stops to wait for another request. 9.2.4.2 Burst Request When a burst request is detected, the μDMA controller transfers the number of items that is the lesser of the arbitration size or the number of items remaining in the transfer. Therefore, the arbitration size should be the same as the number of data items that the peripheral can accommodate when making a burst request. For example, the UART generates a burst request based on the FIFO trigger level. In this case, the arbitration size should be set to the amount of data that the FIFO can transfer when the trigger level is reached. A burst transfer runs to completion once it is started, and cannot be interrupted, even by a higher priority channel. Burst transfers complete in a shorter time than the same number of non-burst transfers. It may be desirable to use only burst transfers and not allow single transfers. For example, perhaps the nature of the data is such that it only makes sense when transferred together as a single unit rather than one piece at a time. The single request can be disabled by using the DMA Channel Useburst Set (DMAUSEBURSTSET) register. By setting the bit for a channel in this register, the μDMA controller only responds to burst requests for that channel. 9.2.5 Channel Configuration The μDMA controller uses an area of system memory to store a set of channel control structures in a table. The control table may have one or two entries for each μDMA channel. Each entry in the table structure contains source and destination pointers, transfer size, and transfer mode. The control table can be located anywhere in system memory, but it must be contiguous and aligned on a 1024-byte boundary. Table 9-3 on page 684 shows the layout in memory of the channel control table. Each channel may have one or two control structures in the control table: a primary control structure and an optional alternate control structure. The table is organized so that all of the primary entries are in the first half of the table, and all the alternate structures are in the second half of the table. The primary entry is used for simple transfer modes where transfers can be reconfigured and restarted after each transfer is complete. In this case, the alternate control structures are not used and therefore only the first half of the table must be allocated in memory; the second half of the control table is not necessary, and that memory can be used for something else. If a more complex transfer mode is used such as ping-pong or scatter-gather, then the alternate control structure is also used and memory space should be allocated for the entire table. Any unused memory in the control table may be used by the application. This includes the control structures for any channels that are unused by the application as well as the unused control word for each channel. June 18, 2014 683 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Table 9-3. Control Structure Memory Map Offset Channel 0x0 0, Primary 0x10 1, Primary ... ... 0x1F0 31, Primary 0x200 0, Alternate 0x210 1, Alternate ... 0x3F0 ... 31, Alternate Table 9-4 shows an individual control structure entry in the control table. Each entry is aligned on a 16-byte boundary. The entry contains four long words: the source end pointer, the destination end pointer, the control word, and an unused entry. The end pointers point to the ending address of the transfer and are inclusive. If the source or destination is non-incrementing (as for a peripheral register), then the pointer should point to the transfer address. Table 9-4. Channel Control Structure Offset Description 0x000 Source End Pointer 0x004 Destination End Pointer 0x008 Control Word 0x00C Unused The control word contains the following fields: ■ Source and destination data sizes ■ Source and destination address increment size ■ Number of transfers before bus arbitration ■ Total number of items to transfer ■ Useburst flag ■ Transfer mode The control word and each field are described in detail in “μDMA Channel Control Structure” on page 702. The μDMA controller updates the transfer size and transfer mode fields as the transfer is performed. At the end of a transfer, the transfer size indicates 0, and the transfer mode indicates "stopped." Because the control word is modified by the μDMA controller, it must be reconfigured before each new transfer. The source and destination end pointers are not modified, so they can be left unchanged if the source or destination addresses remain the same. Prior to starting a transfer, a μDMA channel must be enabled by setting the appropriate bit in the DMA Channel Enable Set (DMAENASET) register. A channel can be disabled by setting the channel bit in the DMA Channel Enable Clear (DMAENACLR) register. At the end of a complete μDMA transfer, the controller automatically disables the channel. 684 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 9.2.6 Transfer Modes The μDMA controller supports several transfer modes. Two of the modes support simple one-time transfers. Several complex modes support a continuous flow of data. 9.2.6.1 Stop Mode While Stop is not actually a transfer mode, it is a valid value for the mode field of the control word. When the mode field has this value, the μDMA controller does not perform any transfers and disables the channel if it is enabled. At the end of a transfer, the μDMA controller updates the control word to set the mode to Stop. 9.2.6.2 Basic Mode In Basic mode, the μDMA controller performs transfers as long as there are more items to transfer, and a transfer request is present. This mode is used with peripherals that assert a μDMA request signal whenever the peripheral is ready for a data transfer. Basic mode should not be used in any situation where the request is momentary even though the entire transfer should be completed. For example, a software-initiated transfer creates a momentary request, and in Basic mode, only the number of transfers specified by the ARBSIZE field in the DMA Channel Control Word (DMACHCTL) register is transferred on a software request, even if there is more data to transfer. When all of the items have been transferred using Basic mode, the μDMA controller sets the mode for that channel to Stop. BASIC mode can be programmed to ignore when XFERSIZE reaches 0x000 and continue copying on request until the channel is stopped manually. If the NXTUSEBURST bit in the uDMA Channel Control Word (DMACHCTL) register is set while in BASIC mode and the XFERSIZE reaches 0x000 and is not written back, transfers continue until the request is deasserted by the peripheral. 9.2.6.3 Auto Mode Auto mode is similar to Basic mode, except that once a transfer request is received, the transfer runs to completion, even if the μDMA request is removed. This mode is suitable for software-triggered transfers. Generally, Auto mode is not used with a peripheral. When all the items have been transferred using Auto mode, the μDMA controller sets the mode for that channel to Stop. 9.2.6.4 Ping-Pong Ping-Pong mode is used to support a continuous data flow to or from a peripheral. To use Ping-Pong mode, both the primary and alternate data structures must be implemented. Both structures are set up by the processor for data transfer between memory and a peripheral. The transfer is started using the primary control structure. When the transfer using the primary control structure is complete, the μDMA controller reads the alternate control structure for that channel to continue the transfer. Each time this happens, an interrupt is generated, and the processor can reload the control structure for the just-completed transfer. Data flow can continue indefinitely this way, using the primary and alternate control structures to switch back and forth between buffers as the data flows to or from the peripheral. Refer to Figure 9-2 on page 686 for an example showing operation in Ping-Pong mode. June 18, 2014 685 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Figure 9-2. Example of Ping-Pong μDMA Transaction µDMA Controller SOURCE DEST CONTROL Unused transfers using BUFFER A transfer continues using alternate Primary Structure Cortex-M4F Processor SOURCE DEST CONTROL Unused Pe ri Time AI SOURCE DEST CONTROL Unused Alternate Structure 9.2.6.5 SOURCE DEST CONTROL Unused nte rru pt transfers using BUFFER B BUFFER B · Process data in BUFFER A · Reload primary structure Pe rip he ral /µD M AI nte transfers using BUFFER A rru pt BUFFER A · Process data in BUFFER B · Reload alternate structure transfer continues using alternate Primary Structure ph era l /µD M transfer continues using primary Alternate Structure BUFFER A Pe rip h era l/µ DM AI nte transfers using BUFFER B rru pt BUFFER B · Process data in BUFFER B · Reload alternate structure Memory Scatter-Gather Memory Scatter-Gather mode is a complex mode used when data must be transferred to or from varied locations in memory instead of a set of contiguous locations in a memory buffer. For example, a gather μDMA operation could be used to selectively read the payload of several stored packets of a communication protocol and store them together in sequence in a memory buffer. 686 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller In Memory Scatter-Gather mode, the primary control structure is used to program the alternate control structure from a table in memory. The table is set up by the processor software and contains a list of control structures, each containing the source and destination end pointers, and the control word for a specific transfer. The mode of each control word must be set to Scatter-Gather mode. Each entry in the table is copied in turn to the alternate structure where it is then executed. The μDMA controller alternates between using the primary control structure to copy the next transfer instruction from the list and then executing the new transfer instruction. The end of the list is marked by programming the control word for the last entry to use Auto transfer mode. Once the last transfer is performed using Auto mode, the μDMA controller stops. A completion interrupt is generated only after the last transfer. It is possible to loop the list by having the last entry copy the primary control structure to point back to the beginning of the list (or to a new list). It is also possible to trigger a set of other channels to perform a transfer, either directly, by programming a write to the software trigger for another channel, or indirectly, by causing a peripheral action that results in a μDMA request. By programming the μDMA controller using this method, a set of up to 256 arbitrary transfers can be performed based on a single μDMA request. Refer to Figure 9-3 on page 688 and Figure 9-4 on page 689, which show an example of operation in Memory Scatter-Gather mode. This example shows a gather operation, where data in three separate buffers in memory is copied together into one buffer. Figure 9-3 on page 688 shows how the application sets up a μDMA task list in memory that is used by the controller to perform three sets of copy operations from different locations in memory. The primary control structure for the channel that is used for the operation is configured to copy from the task list to the alternate control structure. Figure 9-4 on page 689 shows the sequence as the μDMA controller performs the three sets of copy operations. First, using the primary control structure, the μDMA controller loads the alternate control structure with task A. It then performs the copy operation specified by task A, copying the data from the source buffer A to the destination buffer. Next, the μDMA controller again uses the primary control structure to load task B into the alternate control structure, and then performs the B operation with the alternate control structure. The process is repeated for task C. June 18, 2014 687 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Figure 9-3. Memory Scatter-Gather, Setup and Configuration 1 2 3 Source and Destination Buffer in Memory Task List in Memory Channel Control Table in Memory 4 WORDS (SRC A) SRC A DST ITEMS=4 16 WORDS (SRC B) SRC Unused DST SRC ITEMS=12 DST B “TASK” A ITEMS=16 Channel Primary Control Structure “TASK” B Unused SRC DST ITEMS=1 “TASK” C Unused SRC DST Channel Alternate Control Structure ITEMS=n 1 WORD (SRC C) C 4 (DEST A) 16 (DEST B) 1 (DEST C) NOTES: 1. Application has a need to copy data items from three separate locations in memory into one combined buffer. 2. Application sets up µDMA “task list” in memory, which contains the pointers and control configuration for three µDMA copy “tasks.” 3. Application sets up the channel primary control structure to copy each task configuration, one at a time, to the alternate control structure, where it is executed by the µDMA controller. 4. The SRC and DST pointers in the task list must point to the last location in the corresponding buffer. 688 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 9-4. Memory Scatter-Gather, μDMA Copy Sequence Task List in Memory Buffers in Memory µDMA Control Table in Memory SRC A SRC SRC B PRI COPIED DST TASK A TASK B SRC SRC C ALT COPIED DST TASK C DEST A DEST B DEST C Then, using the channel’s alternate control structure, the µDMA controller copies data from the source buffer A to the destination buffer. Using the channel’s primary control structure, the µDMA controller copies task A configuration to the channel’s alternate control structure. Task List in Memory Buffers in Memory µDMA Control Table in Memory SRC A SRC B SRC PRI DST TASK A SRC TASK B TASK C SRC C COPIED ALT COPIED DST DEST A DEST B DEST C Then, using the channel’s alternate control structure, the µDMA controller copies data from the source buffer B to the destination buffer. Using the channel’s primary control structure, the µDMA controller copies task B configuration to the channel’s alternate control structure. Task List in Memory Buffers in Memory µDMA Control Table in Memory SRC A SRC SRC B PRI DST TASK A SRC TASK B TASK C SRC C ALT DST DEST A COPIED COPIED DEST B DEST C Using the channel’s primary control structure, the µDMA controller copies task C configuration to the channel’s alternate control structure. Then, using the channel’s alternate control structure, the µDMA controller copies data from the source buffer C to the destination buffer. June 18, 2014 689 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) 9.2.6.6 Peripheral Scatter-Gather Peripheral Scatter-Gather mode is very similar to Memory Scatter-Gather, except that the transfers are controlled by a peripheral making a μDMA request. Upon detecting a request from the peripheral, the μDMA controller uses the primary control structure to copy one entry from the list to the alternate control structure and then performs the transfer. At the end of this transfer, the primary control structure will copy the next task to the alternate control structure . If the next task is a memory-to-memory transfer, execution will start immediately and run to completion; if the next task is a peripheral-type transfer, the μDMA will wait for a peripheral request to begin. By using this method, the μDMA controller can transfer data to or from a peripheral from a set of arbitrary locations whenever the peripheral is ready to transfer data. Refer to Figure 9-5 on page 691 and Figure 9-6 on page 692, which show an example of operation in Peripheral Scatter-Gather mode. This example shows a gather operation, where data from three separate buffers in memory is copied to a single peripheral data register. Figure 9-5 on page 691 shows how the application sets up a µDMA task list in memory that is used by the controller to perform three sets of copy operations from different locations in memory. The primary control structure for the channel that is used for the operation is configured to copy from the task list to the alternate control structure. Figure 9-6 on page 692 shows the sequence as the µDMA controller performs the three sets of copy operations. First, using the primary control structure, the µDMA controller loads the alternate control structure with task A. It then performs the copy operation specified by task A, copying the data from the source buffer A to the peripheral data register. Next, the µDMA controller again uses the primary control structure to load task B into the alternate control structure, and then performs the B operation with the alternate control structure. The process is repeated for task C. 690 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 9-5. Peripheral Scatter-Gather, Setup and Configuration 1 2 3 Source Buffer in Memory Task List in Memory Channel Control Table in Memory 4 WORDS (SRC A) SRC A DST ITEMS=4 16 WORDS (SRC B) SRC DST SRC ITEMS=12 DST B “TASK” A Unused ITEMS=16 Channel Primary Control Structure “TASK” B Unused SRC DST ITEMS=1 “TASK” C Unused SRC DST Channel Alternate Control Structure ITEMS=n 1 WORD (SRC C) C Peripheral Data Register DEST NOTES: 1. Application has a need to copy data items from three separate locations in memory into a peripheral data register. 2. Application sets up µDMA “task list” in memory, which contains the pointers and control configuration for three µDMA copy “tasks.” 3. Application sets up the channel primary control structure to copy each task configuration, one at a time, to the alternate control structure, where it is executed by the µDMA controller. June 18, 2014 691 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Figure 9-6. Peripheral Scatter-Gather, μDMA Copy Sequence Task List in Memory Buffers in Memory µDMA Control Table in Memory SRC A SRC SRC B PRI COPIED DST TASK A TASK B SRC SRC C ALT COPIED DST TASK C Then, using the channel’s alternate control structure, the µDMA controller copies data from the source buffer A to the peripheral data register. Using the channel’s primary control structure, the µDMA controller copies task A configuration to the channel’s alternate control structure. Task List in Memory Peripheral Data Register Buffers in Memory µDMA Control Table in Memory SRC A SRC SRC B PRI DST TASK A SRC TASK B TASK C SRC C COPIED ALT COPIED DST Then, using the channel’s alternate control structure, the µDMA controller copies data from the source buffer B to the peripheral data register. Using the channel’s primary control structure, the µDMA controller copies task B configuration to the channel’s alternate control structure. Task List in Memory Peripheral Data Register Buffers in Memory µDMA Control Table in Memory SRC A SRC SRC B PRI DST TASK A SRC TASK B TASK C SRC C ALT DST COPIED COPIED Peripheral Data Register Using the channel’s primary control structure, the µDMA controller copies task C configuration to the channel’s alternate control structure. Then, using the channel’s alternate control structure, the µDMA controller copies data from the source buffer C to the peripheral data register. 692 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 9.2.7 Transfer Size and Increment The μDMA controller supports transfer data sizes of 8, 16, or 32 bits. The source and destination data size must be the same for any given transfer. The source and destination address can be auto-incremented by bytes, half-words, or words, or can be set to no increment. The source and destination address increment values can be set independently, and it is not necessary for the address increment to match the data size as long as the increment is the same or larger than the data size. For example, it is possible to perform a transfer using 8-bit data size, but using an address increment of full words (4 bytes). The data to be transferred must be aligned in memory according to the data size (8, 16, or 32 bits). Table 9-5 shows the configuration to read from a peripheral that supplies 8-bit data. Table 9-5. μDMA Read Example: 8-Bit Peripheral 9.2.8 Field Configuration Source data size 8 bits Destination data size 8 bits Source address increment No increment Destination address increment Byte Source end pointer Peripheral read FIFO register Destination end pointer End of the data buffer in memory Peripheral Interface There are three main classes of uDMA-connected peripherals: ■ Peripherals with FIFOs serviced by the uDMA to transmit or receive data. ■ Peripherals that provide trigger inputs to the uDMA 9.2.8.1 FIFO Peripherals FIFO peripherals contain a FIFO of data to be sent and a FIFO of data that has been received. The uDMA controller is used to transfer data between these FIFOs and system memory. For example, when a UART FIFO contains one or more entries, a single transfer request is sent to the uDMA for processing. If this request has not been processed and the UART FIFO reaches the interrupt FIFO level set in the UART Interrupt FIFO Level Select (UARTIFLS) register, another interrupt is sent to the uDMA which is higher priority than the single-transfer request. In this instance, an ARBSIZ transfer is performed as configured in the DMACHCTL register. After the transfer is complete, the DMA sends a receive or transmit complete interrupt to the UART Raw Interrupt Status (UARTRIS) register. If the FIFO peripheral's SETn bit is set in the DMA Channel Useburst Set (DMAUSEBURSTSET) register, then the uDMA will only perform transfers defined by the ARBSIZ bit field in the DMACHCTL register for better bus utilization. For peripherals that tend to transmit and receive in bursts, such as the UART, we recommend against the use of this configuration since it could cause the tail end of transmissions to stick in the FIFO. 9.2.8.2 Trigger Peripherals Certain peripherals, such as the general purpose timer, trigger an interrupt to the uDMA controller when a programmed event occurs. When a trigger event occurs, the uDMA executes a transfer defined by the ARBSIZ bit field in the DMACHCTL register. If only a single transfer is needed for a uDMA trigger, then the ARBSIZ field is set to 0x1. June 18, 2014 693 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) If the trigger peripheral generates another uDMA request while the prior one is being serviced and that particular channel is the highest priority asserted channel, the second request will be processed as soon as the handling of the first is complete. If two additional trigger peripheral uDMA requests are generated prior to the completion of the first, the third request is lost. 9.2.9 Software Request A transfer is initiated by software by first configuring and enabling the transfer, and then issuing a software request using the DMA Channel Software Request (DMASWREQ) register. For software-based transfers, the Auto transfer mode should be used. It is possible to initiate a transfer on any available software channel using the DMASWREQ register. If a request is initiated by software using a peripheral μDMA channel, then the completion interrupt occurs on the interrupt vector for the peripheral instead of the software interrupt vector. Any peripheral channel may be used for software requests as long as the corresponding peripheral is not using μDMA for data transfer. Note: 9.2.10 Channels designated in the table as only "Software" are dedicated software channels. When only one software request is required in an application, dedicated software channels can be used. If multiple software requests in code are required, then peripheral channel software requests should be used for proper µDMA completion acknowledgement. Interrupts and Errors Depending on the peripheral, the μDMA can indicate transfer completion at the end of an entire transfer or when a FIFO or buffer reaches a certain level (see Table 9-2 on page 682 and the individual peripheral chapters). When a μDMA transfer is complete, a dma_done signal is sent to the peripheral that initiated the μDMA event. Interrupts can be enabled within the peripheral to trigger on μDMA transfer completion. Please refer to the individual peripheral chapters for more information on peripheral μDMA interrupts. If the transfer uses the software μDMA channel, then the completion interrupt occurs on the dedicated software μDMA interrupt vector (see Table 9-6 on page 694). If the μDMA controller encounters a bus or memory protection error as it attempts to perform a data transfer, it disables the μDMA channel that caused the error and generates an interrupt on the μDMA error interrupt vector. The processor can read the DMA Bus Error Clear (DMAERRCLR) register to determine if an error is pending. The ERRCLR bit is set if an error occurred. The error can be cleared by writing a 1 to the ERRCLR bit. Table 9-6 shows the dedicated interrupt assignments for the μDMA controller. Table 9-6. μDMA Interrupt Assignments Interrupt Assignment 44 μDMA Software Channel Transfer 45 μDMA Error 9.3 Initialization and Configuration 9.3.1 Module Initialization Before the μDMA controller can be used, it must be enabled in the System Control block and in the peripheral. The location of the channel control structure must also be programmed. The following steps should be performed one time during system initialization: 1. Enable the μDMA clock using the RCGCDMA register (see page 385). 694 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 2. Enable the μDMA controller by setting the MASTEREN bit of the DMA Configuration (DMACFG) register. 3. Program the location of the channel control table by writing the base address of the table to the DMA Channel Control Base Pointer (DMACTLBASE) register. The base address must be aligned on a 1024-byte boundary. 9.3.2 Configuring a Memory-to-Memory Transfer μDMA channel 30 is dedicated for software-initiated transfers. However, any channel can be used for software-initiated, memory-to-memory transfer if the associated peripheral is not being used. 9.3.2.1 Configure the Channel Attributes First, configure the channel attributes: 1. Program bit 30 of the DMA Channel Priority Set (DMAPRIOSET) or DMA Channel Priority Clear (DMAPRIOCLR) registers to set the channel to High priority or Default priority. 2. Set bit 30 of the DMA Channel Primary Alternate Clear (DMAALTCLR) register to select the primary channel control structure for this transfer. 3. Set bit 30 of the DMA Channel Useburst Clear (DMAUSEBURSTCLR) register to allow the μDMA controller to respond to single and burst requests. 4. Set bit 30 of the DMA Channel Request Mask Clear (DMAREQMASKCLR) register to allow the μDMA controller to recognize requests for this channel. 9.3.2.2 Configure the Channel Control Structure Now the channel control structure must be configured. This example transfers 256 words from one memory buffer to another. Channel 30 is used for a software transfer, and the control structure for channel 30 is at offset 0x1E0 of the channel control table. The channel control structure for channel 30 is located at the offsets shown in Table 9-7. Table 9-7. Channel Control Structure Offsets for Channel 30 Offset Description Control Table Base + 0x1E0 Channel 30 Source End Pointer Control Table Base + 0x1E4 Channel 30 Destination End Pointer Control Table Base + 0x1E8 Channel 30 Control Word Configure the Source and Destination The source and destination end pointers must be set to the last address for the transfer (inclusive). 1. Program the source end pointer at offset 0x1E0 to the address of the source buffer + 0x3FC. 2. Program the destination end pointer at offset 0x1E4 to the address of the destination buffer + 0x3FC. The control word at offset 0x1E8 must be programmed according to Table 9-8. June 18, 2014 695 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Table 9-8. Channel Control Word Configuration for Memory Transfer Example Field in DMACHCTL Bits Value DSTINC 31:30 2 32-bit destination address increment DSTSIZE 29:28 2 32-bit destination data size SRCINC 27:26 2 32-bit source address increment SRCSIZE 25:24 2 32-bit source data size reserved 23:22 0 Reserved 21 0 Privileged access protection for destination data writes 20:19 0 Reserved 18 0 Privileged access protection for source data reads ARBSIZE 17:14 3 Arbitrates after 8 transfers XFERSIZE 13:4 255 3 0 N/A for this transfer type 2:0 2 Use Auto-request transfer mode DSTPROT0 reserved SRCPROT0 NXTUSEBURST XFERMODE Description Transfer 256 items Configure Peripheral Interrupts For memory-to-memory transfers, the peripheral involved must be configured to generate an interrupt when the µDMA has completed its transfer. Upon completion, the µDMA will send a dma_done signal to the peripheral. 9.3.2.3 Start the Transfer Now the channel is configured and is ready to start. 1. Enable the channel by setting bit 30 of the DMA Channel Enable Set (DMAENASET) register. 2. Issue a transfer request by setting bit 30 of the DMA Channel Software Request (DMASWREQ) register. The μDMA transfer begins. If the interrupt is enabled, then the processor is notified by interrupt when the transfer is complete. If needed, the status can be checked by reading bit 30 of the DMAENASET register. This bit is automatically cleared when the transfer is complete. The status can also be checked by reading the XFERMODE field of the channel control word at offset 0x1E8. This field is automatically cleared at the end of the transfer. 9.3.3 Configuring a Peripheral for Simple Transmit This example configures the μDMA controller to transmit a buffer of data to a peripheral. The peripheral has a transmit FIFO with a trigger level of 4. The example peripheral uses μDMA channel 7. 9.3.3.1 Configure the Channel Attributes First, configure the channel attributes: 1. Configure bit 7 of the DMA Channel Priority Set (DMAPRIOSET) or DMA Channel Priority Clear (DMAPRIOCLR) registers to set the channel to High priority or Default priority. 2. Set bit 7 of the DMA Channel Primary Alternate Clear (DMAALTCLR) register to select the primary channel control structure for this transfer. 696 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 3. Set bit 7 of the DMA Channel Useburst Clear (DMAUSEBURSTCLR) register to allow the μDMA controller to respond to single and burst requests. 4. Set bit 7 of the DMA Channel Request Mask Clear (DMAREQMASKCLR) register to allow the μDMA controller to recognize requests for this channel. 9.3.3.2 Configure the Channel Control Structure This example transfers 64 bytes from a memory buffer to the peripheral's transmit FIFO register using μDMA channel 7. The control structure for channel 7 is at offset 0x070 of the channel control table. The channel control structure for channel 7 is located at the offsets shown in Table 9-9. Table 9-9. Channel Control Structure Offsets for Channel 7 Offset Description Control Table Base + 0x070 Channel 7 Source End Pointer Control Table Base + 0x074 Channel 7 Destination End Pointer Control Table Base + 0x078 Channel 7 Control Word Configure the Source and Destination The source and destination end pointers must be set to the last address for the transfer (inclusive). Because the peripheral pointer does not change, it simply points to the peripheral's data register. 1. Program the source end pointer at offset 0x070 to the address of the source buffer + 0x3F. 2. Program the destination end pointer at offset 0x074 to the address of the peripheral's transmit FIFO register. The control word at offset 0x078 must be programmed according to Table 9-10. Table 9-10. Channel Control Word Configuration for Peripheral Transmit Example Field in DMACHCTL Bits Value DSTINC 31:30 3 Destination address does not increment DSTSIZE 29:28 0 8-bit destination data size SRCINC 27:26 0 8-bit source address increment SRCSIZE 25:24 0 8-bit source data size reserved 23:22 0 Reserved 21 0 Privileged access protection for destination data writes 20:19 0 Reserved 18 0 Privileged access protection for source data reads ARBSIZE 17:14 2 Arbitrates after 4 transfers XFERSIZE 13:4 63 Transfer 64 items 3 0 N/A for this transfer type 2:0 1 Use Basic transfer mode DSTPROT0 reserved SRCPROT0 NXTUSEBURST XFERMODE Note: Description In this example, it is not important if the peripheral makes a single request or a burst request. Because the peripheral has a FIFO that triggers at a level of 4, the arbitration size is set to 4. If the peripheral does make a burst request, then 4 bytes are transferred, which is what the FIFO can accommodate. If the peripheral makes a single request (if there is any space June 18, 2014 697 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) in the FIFO), then one byte is transferred at a time. If it is important to the application that transfers only be made in bursts, then the Channel Useburst SET[7] bit should be set in the DMA Channel Useburst Set (DMAUSEBURSTSET) register. 9.3.3.3 Start the Transfer Now the channel is configured and is ready to start. 1. Enable the channel by setting bit 7 of the DMA Channel Enable Set (DMAENASET) register. The μDMA controller is now configured for transfer on channel 7. The controller makes transfers to the peripheral whenever the peripheral asserts a μDMA request. The transfers continue until the entire buffer of 64 bytes has been transferred. When that happens, the μDMA controller disables the channel and sets the XFERMODE field of the channel control word to 0 (Stopped). The status of the transfer can be checked by reading bit 7 of the DMA Channel Enable Set (DMAENASET) register. This bit is automatically cleared when the transfer is complete. The status can also be checked by reading the XFERMODE field of the channel control word at offset 0x078. This field is automatically cleared at the end of the transfer. If peripheral interrupts are enabled, then the peripheral generates an interrupt when the entire transfer is complete. 9.3.4 Configuring a Peripheral for Ping-Pong Receive This example configures the μDMA controller to continuously receive 8-bit data from a peripheral into a pair of 64-byte buffers. The peripheral has a receive FIFO with a trigger level of 8. The example peripheral uses μDMA channel 8. 9.3.4.1 Configure the Channel Attributes First, configure the channel attributes: 1. Configure bit 8 of the DMA Channel Priority Set (DMAPRIOSET) or DMA Channel Priority Clear (DMAPRIOCLR) registers to set the channel to High priority or Default priority. 2. Set bit 8 of the DMA Channel Primary Alternate Clear (DMAALTCLR) register to select the primary channel control structure for this transfer. 3. Set bit 8 of the DMA Channel Useburst Clear (DMAUSEBURSTCLR) register to allow the μDMA controller to respond to single and burst requests. 4. Set bit 8 of the DMA Channel Request Mask Clear (DMAREQMASKCLR) register to allow the μDMA controller to recognize requests for this channel. 9.3.4.2 Configure the Channel Control Structure This example transfers bytes from the peripheral's receive FIFO register into two memory buffers of 64 bytes each. As data is received, when one buffer is full, the μDMA controller switches to use the other. To use Ping-Pong buffering, both primary and alternate channel control structures must be used. The primary control structure for channel 8 is at offset 0x080 of the channel control table, and the alternate channel control structure is at offset 0x280. The channel control structures for channel 8 are located at the offsets shown in Table 9-11. 698 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 9-11. Primary and Alternate Channel Control Structure Offsets for Channel 8 Offset Description Control Table Base + 0x080 Channel 8 Primary Source End Pointer Control Table Base + 0x084 Channel 8 Primary Destination End Pointer Control Table Base + 0x088 Channel 8 Primary Control Word Control Table Base + 0x280 Channel 8 Alternate Source End Pointer Control Table Base + 0x284 Channel 8 Alternate Destination End Pointer Control Table Base + 0x288 Channel 8 Alternate Control Word Configure the Source and Destination The source and destination end pointers must be set to the last address for the transfer (inclusive). Because the peripheral pointer does not change, it simply points to the peripheral's data register. Both the primary and alternate sets of pointers must be configured. 1. Program the primary source end pointer at offset 0x080 to the address of the peripheral's receive buffer. 2. Program the primary destination end pointer at offset 0x084 to the address of ping-pong buffer A + 0x3F. 3. Program the alternate source end pointer at offset 0x280 to the address of the peripheral's receive buffer. 4. Program the alternate destination end pointer at offset 0x284 to the address of ping-pong buffer B + 0x3F. The primary control word at offset 0x088 and the alternate control word at offset 0x288 are initially programmed the same way. 1. Program the primary channel control word at offset 0x088 according to Table 9-12. 2. Program the alternate channel control word at offset 0x288 according to Table 9-12. Table 9-12. Channel Control Word Configuration for Peripheral Ping-Pong Receive Example Field in DMACHCTL Bits Value DSTINC 31:30 0 8-bit destination address increment DSTSIZE 29:28 0 8-bit destination data size SRCINC 27:26 3 Source address does not increment SRCSIZE 25:24 0 8-bit source data size reserved 23:22 0 Reserved 21 0 Privileged access protection for destination data writes 20:19 0 Reserved 18 0 Privileged access protection for source data reads DSTPROT0 reserved SRCPROT0 Description ARBSIZE 17:14 3 Arbitrates after 8 transfers XFERSIZE 13:4 63 Transfer 64 items 3 0 N/A for this transfer type 2:0 3 Use Ping-Pong transfer mode NXTUSEBURST XFERMODE June 18, 2014 699 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Note: 9.3.4.3 In this example, it is not important if the peripheral makes a single request or a burst request. Because the peripheral has a FIFO that triggers at a level of 8, the arbitration size is set to 8. If the peripheral does make a burst request, then 8 bytes are transferred, which is what the FIFO can accommodate. If the peripheral makes a single request (if there is any data in the FIFO), then one byte is transferred at a time. If it is important to the application that transfers only be made in bursts, then the Channel Useburst SET[8] bit should be set in the DMA Channel Useburst Set (DMAUSEBURSTSET) register. Configure the Peripheral Interrupt An interrupt handler should be configured when using μDMA Ping-Pong mode, it is best to use an interrupt handler. However, the Ping-Pong mode can be configured without interrupts by polling. The interrupt handler is triggered after each buffer is complete. 1. Configure and enable an interrupt handler for the peripheral. 9.3.4.4 Enable the μDMA Channel Now the channel is configured and is ready to start. 1. Enable the channel by setting bit 8 of the DMA Channel Enable Set (DMAENASET) register. 9.3.4.5 Process Interrupts The μDMA controller is now configured and enabled for transfer on channel 8. When the peripheral asserts the μDMA request signal, the μDMA controller makes transfers into buffer A using the primary channel control structure. When the primary transfer to buffer A is complete, it switches to the alternate channel control structure and makes transfers into buffer B. At the same time, the primary channel control word mode field is configured to indicate Stopped, and an interrupt is generated in the peripheral's raw interrupt status register. When an interrupt is triggered, the interrupt handler must determine which buffer is complete and process the data or set a flag that the data must be processed by non-interrupt buffer processing code. Then the next buffer transfer must be set up. In the interrupt handler: 1. Read the primary channel control word at offset 0x088 and check the XFERMODE field. If the field is 0, this means buffer A is complete. If buffer A is complete, then: a. Process the newly received data in buffer A or signal the buffer processing code that buffer A has data available. b. Reprogram the primary channel control word at offset 0x88 according to Table 9-12 on page 699. 2. Read the alternate channel control word at offset 0x288 and check the XFERMODE field. If the field is 0, this means buffer B is complete. If buffer B is complete, then: a. Process the newly received data in buffer B or signal the buffer processing code that buffer B has data available. b. Reprogram the alternate channel control word at offset 0x288 according to Table 9-12 on page 699. 700 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 9.3.5 Configuring Channel Assignments Channel assignments for each μDMA channel can be changed using the DMACHMAPn registers. Each 4-bit field represents a μDMA channel. Refer to Table 9-1 on page 680 for channel assignments. For example, to use UART1 RX on channel 8, configure the CH8SEL bit in the DMACHMAP1 register to be 0x1. If a peripheral is enabled on two different channels, the μDMA channel that has the highest priority for that peripheral takes precedence. Thus, if UART 1 RX is enabled on both channel 8 and channel 22, the UART1 RX channel 22 priority needs to be lowered before channel 8 UART1 RX can be accessed by the μDMA. 9.4 Register Map Table 9-13 on page 701 lists the μDMA channel control structures and registers. The channel control structure shows the layout of one entry in the channel control table. The channel control table is located in system memory, and the location is determined by the application, thus the base address is n/a (not applicable) and noted as such above the register descriptions. In the table below, the offset for the channel control structures is the offset from the entry in the channel control table. See “Channel Configuration” on page 683 and Table 9-3 on page 684 for a description of how the entries in the channel control table are located in memory. The μDMA register addresses are given as a hexadecimal increment, relative to the μDMA base address of 0x400F.F000. Note that the μDMA module clock must be enabled before the registers can be programmed (see page 385). There must be a delay of 3 system clocks after the μDMA module clock is enabled before any μDMA module registers are accessed. Table 9-13. μDMA Register Map Offset Name Type Reset Description See page μDMA Channel Control Structure (Offset from Channel Control Table Base) 0x000 DMASRCENDP RW - DMA Channel Source Address End Pointer 703 0x004 DMADSTENDP RW - DMA Channel Destination Address End Pointer 704 0x008 DMACHCTL RW - DMA Channel Control Word 705 DMA Status 710 DMA Configuration 712 μDMA Registers (Offset from μDMA Base Address) 0x000 DMASTAT RO 0x001F.0000 0x004 DMACFG WO - 0x008 DMACTLBASE RW 0x0000.0000 DMA Channel Control Base Pointer 713 0x00C DMAALTBASE RO 0x0000.0200 DMA Alternate Channel Control Base Pointer 714 0x010 DMAWAITSTAT RO 0x03C3.CF00 DMA Channel Wait-on-Request Status 715 0x014 DMASWREQ WO - DMA Channel Software Request 716 0x018 DMAUSEBURSTSET RW 0x0000.0000 DMA Channel Useburst Set 717 0x01C DMAUSEBURSTCLR WO - DMA Channel Useburst Clear 718 0x020 DMAREQMASKSET RW 0x0000.0000 DMA Channel Request Mask Set 719 0x024 DMAREQMASKCLR WO - DMA Channel Request Mask Clear 720 June 18, 2014 701 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Table 9-13. μDMA Register Map (continued) Offset Name Type Reset 0x028 DMAENASET RW 0x0000.0000 0x02C DMAENACLR WO - 0x030 DMAALTSET RW 0x0000.0000 0x034 DMAALTCLR WO - 0x038 DMAPRIOSET RW 0x0000.0000 0x03C DMAPRIOCLR WO - 0x04C DMAERRCLR RW 0x500 DMACHASGN 0x510 Description See page DMA Channel Enable Set 721 DMA Channel Enable Clear 722 DMA Channel Primary Alternate Set 723 DMA Channel Primary Alternate Clear 724 DMA Channel Priority Set 725 DMA Channel Priority Clear 726 0x0000.0000 DMA Bus Error Clear 727 RW 0x0000.0000 DMA Channel Assignment 728 DMACHMAP0 RW 0x0000.0000 DMA Channel Map Select 0 729 0x514 DMACHMAP1 RW 0x0000.0000 DMA Channel Map Select 1 730 0x518 DMACHMAP2 RW 0x0000.0000 DMA Channel Map Select 2 731 0x51C DMACHMAP3 RW 0x0000.0000 DMA Channel Map Select 3 732 0xFD0 DMAPeriphID4 RO 0x0000.0004 DMA Peripheral Identification 4 737 0xFE0 DMAPeriphID0 RO 0x0000.0030 DMA Peripheral Identification 0 733 0xFE4 DMAPeriphID1 RO 0x0000.00B2 DMA Peripheral Identification 1 734 0xFE8 DMAPeriphID2 RO 0x0000.000B DMA Peripheral Identification 2 735 0xFEC DMAPeriphID3 RO 0x0000.0000 DMA Peripheral Identification 3 736 0xFF0 DMAPCellID0 RO 0x0000.000D DMA PrimeCell Identification 0 738 0xFF4 DMAPCellID1 RO 0x0000.00F0 DMA PrimeCell Identification 1 739 0xFF8 DMAPCellID2 RO 0x0000.0005 DMA PrimeCell Identification 2 740 0xFFC DMAPCellID3 RO 0x0000.00B1 DMA PrimeCell Identification 3 741 9.5 μDMA Channel Control Structure The μDMA Channel Control Structure holds the transfer settings for a μDMA channel. Each channel has two control structures, which are located in a table in system memory. Refer to “Channel Configuration” on page 683 for an explanation of the Channel Control Table and the Channel Control Structure. The channel control structure is one entry in the channel control table. Each channel has a primary and alternate structure. The primary control structures are located at offsets 0x0, 0x10, 0x20 and so on. The alternate control structures are located at offsets 0x200, 0x210, 0x220, and so on. 702 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: DMA Channel Source Address End Pointer (DMASRCENDP), offset 0x000 DMA Channel Source Address End Pointer (DMASRCENDP) is part of the Channel Control Structure and is used to specify the source address for a μDMA transfer. Note: The offset specified is from the base address of the control structure in system memory, not the μDMA module base address. DMA Channel Source Address End Pointer (DMASRCENDP) Base n/a Offset 0x000 Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - ADDR Type Reset ADDR Type Reset Bit/Field Name Type Reset 31:0 ADDR RW - Description Source Address End Pointer This field points to the last address of the μDMA transfer source (inclusive). If the source address is not incrementing (the SRCINC field in the DMACHCTL register is 0x3), then this field points at the source location itself (such as a peripheral data register). June 18, 2014 703 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 2: DMA Channel Destination Address End Pointer (DMADSTENDP), offset 0x004 DMA Channel Destination Address End Pointer (DMADSTENDP) is part of the Channel Control Structure and is used to specify the destination address for a μDMA transfer. Note: The offset specified is from the base address of the control structure in system memory, not the μDMA module base address. DMA Channel Destination Address End Pointer (DMADSTENDP) Base n/a Offset 0x004 Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - ADDR Type Reset ADDR Type Reset Bit/Field Name Type Reset 31:0 ADDR RW - Description Destination Address End Pointer This field points to the last address of the μDMA transfer destination (inclusive). If the destination address is not incrementing (the DSTINC field in the DMACHCTL register is 0x3), then this field points at the destination location itself (such as a peripheral data register). 704 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: DMA Channel Control Word (DMACHCTL), offset 0x008 DMA Channel Control Word (DMACHCTL) is part of the Channel Control Structure and is used to specify parameters of a μDMA transfer. Note: The offset specified is from the base address of the control structure in system memory, not the μDMA module base address. DMA Channel Control Word (DMACHCTL) Base n/a Offset 0x008 Type RW, reset 31 30 DSTINC 28 27 DSTSIZE 26 24 23 SRCSIZE 22 reserved 21 20 19 reserved DSTPROT0 18 17 16 ARBSIZE SRCPROT0 RW - RW - RW - RW - RW - RW - RW - RW - RO 0 RO 0 RW 0 RO - RO - RW 0 RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 ARBSIZE Type Reset 25 SRCINC RW - RW - NXTUSEBURST Type Reset 29 XFERSIZE RW - RW - RW - RW - RW - Bit/Field Name Type Reset 31:30 DSTINC RW - RW - RW - RW - RW - RW - RW - XFERMODE RW - RW - RW - Description Destination Address Increment This field configures the destination address increment. The address increment value must be equal or greater than the value of the destination size (DSTSIZE). Value Description 0x0 Byte Increment by 8-bit locations 0x1 Half-word Increment by 16-bit locations 0x2 Word Increment by 32-bit locations 0x3 No increment Address remains set to the value of the Destination Address End Pointer (DMADSTENDP) for the channel June 18, 2014 705 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Bit/Field Name Type Reset 29:28 DSTSIZE RW - Description Destination Data Size This field configures the destination item data size. Note: DSTSIZE must be the same as SRCSIZE. Value Description 0x0 Byte 8-bit data size 0x1 Half-word 16-bit data size 0x2 Word 32-bit data size 0x3 27:26 SRCINC RW - Reserved Source Address Increment This field configures the source address increment. The address increment value must be equal or greater than the value of the source size (SRCSIZE). Value Description 0x0 Byte Increment by 8-bit locations 0x1 Half-word Increment by 16-bit locations 0x2 Word Increment by 32-bit locations 0x3 No increment Address remains set to the value of the Source Address End Pointer (DMASRCENDP) for the channel 25:24 SRCSIZE RW - Source Data Size This field configures the source item data size. Note: DSTSIZE must be the same as SRCSIZE. Value Description 0x0 Byte 8-bit data size. 0x1 Half-word 16-bit data size. 0x2 Word 32-bit data size. 0x3 23:22 reserved RO 0 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 706 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 21 DSTPROT0 RW 0 Description Destination Privilege Access This bit controls the privilege access protection for destination data writes. Value Description 0 The access is non-privileged. 1 The access is privileged. 20:19 reserved RO - Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 18 SRCPROT0 RW 0 Source Privilege Access This bit controls the privilege access protection for source data reads. Value Description 17:14 ARBSIZE RW - 0 The access is non-privileged. 1 The access is privileged. Arbitration Size This field configures the number of transfers that can occur before the μDMA controller re-arbitrates. The possible arbitration rate configurations represent powers of 2 and are shown below. Value Description 0x0 1 Transfer Arbitrates after each μDMA transfer 0x1 2 Transfers 0x2 4 Transfers 0x3 8 Transfers 0x4 16 Transfers 0x5 32 Transfers 0x6 64 Transfers 0x7 128 Transfers 0x8 256 Transfers 0x9 512 Transfers 0xA-0xF 1024 Transfers In this configuration, no arbitration occurs during the μDMA transfer because the maximum transfer size is 1024. June 18, 2014 707 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Bit/Field Name Type Reset 13:4 XFERSIZE RW - Description Transfer Size (minus 1) This field configures the total number of items to transfer. The value of this field is 1 less than the number to transfer (value 0 means transfer 1 item). The maximum value for this 10-bit field is 1023 which represents a transfer size of 1024 items. The transfer size is the number of items, not the number of bytes. If the data size is 32 bits, then this value is the number of 32-bit words to transfer. The μDMA controller updates this field immediately prior to entering the arbitration process, so it contains the number of outstanding items that is necessary to complete the μDMA cycle. 3 NXTUSEBURST RW - Next Useburst This field controls whether the Useburst SET[n] bit is automatically set for the last transfer of a peripheral scatter-gather operation. Normally, for the last transfer, if the number of remaining items to transfer is less than the arbitration size, the μDMA controller uses single transfers to complete the transaction. If this bit is set, then the controller uses a burst transfer to complete the last transfer. 2:0 XFERMODE RW - μDMA Transfer Mode This field configures the operating mode of the μDMA cycle. Refer to “Transfer Modes” on page 685 for a detailed explanation of transfer modes. Because this register is in system RAM, it has no reset value. Therefore, this field should be initialized to 0 before the channel is enabled. Value Description 0x0 Stop 0x1 Basic 0x2 Auto-Request 0x3 Ping-Pong 0x4 Memory Scatter-Gather 0x5 Alternate Memory Scatter-Gather 0x6 Peripheral Scatter-Gather 0x7 Alternate Peripheral Scatter-Gather XFERMODE Bit Field Values. Stop Channel is stopped or configuration data is invalid. No more transfers can occur. Basic For each trigger (whether from a peripheral or a software request), the μDMA controller performs the number of transfers specified by the ARBSIZE field. Auto-Request The initial request (software- or peripheral-initiated) is sufficient to complete the entire transfer of XFERSIZE items without any further requests. 708 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Ping-Pong This mode uses both the primary and alternate control structures for this channel. When the number of transfers specified by the XFERSIZE field have completed for the current control structure (primary or alternate), the µDMA controller switches to the other one. These switches continue until one of the control structures is not set to ping-pong mode. At that point, the µDMA controller stops. An interrupt is generated on completion of the transfers configured by each control structure. See “Ping-Pong” on page 685. Memory Scatter-Gather When using this mode, the primary control structure for the channel is configured to allow a list of operations (tasks) to be performed. The source address pointer specifies the start of a table of tasks to be copied to the alternate control structure for this channel. The XFERMODE field for the alternate control structure should be configured to 0x5 (Alternate memory scatter-gather) to perform the task. When the task completes, the µDMA switches back to the primary channel control structure, which then copies the next task to the alternate control structure. This process continues until the table of tasks is empty. The last task must have an XFERMODE value other than 0x5. Note that for continuous operation, the last task can update the primary channel control structure back to the start of the list or to another list. See “Memory Scatter-Gather” on page 686. Alternate Memory Scatter-Gather This value must be used in the alternate channel control data structure when the μDMA controller operates in Memory Scatter-Gather mode. Peripheral Scatter-Gather This value must be used in the primary channel control data structure when the μDMA controller operates in Peripheral Scatter-Gather mode. In this mode, the μDMA controller operates exactly the same as in Memory Scatter-Gather mode, except that instead of performing the number of transfers specified by the XFERSIZE field in the alternate control structure at one time, the μDMA controller only performs the number of transfers specified by the ARBSIZE field per trigger; see Basic mode for details. See “Peripheral Scatter-Gather” on page 690. Alternate Peripheral Scatter-Gather This value must be used in the alternate channel control data structure when the μDMA controller operates in Peripheral Scatter-Gather mode. 9.6 μDMA Register Descriptions The register addresses given are relative to the μDMA base address of 0x400F.F000. June 18, 2014 709 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 4: DMA Status (DMASTAT), offset 0x000 The DMA Status (DMASTAT) register returns the status of the μDMA controller. You cannot read this register when the μDMA controller is in the reset state. DMA Status (DMASTAT) Base 0x400F.F000 Offset 0x000 Type RO, reset 0x001F.0000 31 30 29 28 27 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 26 25 24 23 22 21 20 19 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 10 9 8 7 6 5 4 3 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset STATE RO 0 17 16 RO 1 RO 1 RO 1 2 1 0 DMACHANS reserved Type Reset 18 reserved RO 0 MASTEN RO 0 RO 0 Bit/Field Name Type Reset Description 31:21 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 20:16 DMACHANS RO 0x1F Available μDMA Channels Minus 1 This field contains a value equal to the number of μDMA channels the μDMA controller is configured to use, minus one. The value of 0x1F corresponds to 32 μDMA channels. 15:8 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7:4 STATE RO 0x0 Control State Machine Status This field shows the current status of the control state machine. Status can be one of the following. Value Description 0x0 Idle 0x1 Reading channel controller data. 0x2 Reading source end pointer. 0x3 Reading destination end pointer. 0x4 Reading source data. 0x5 Writing destination data. 0x6 Waiting for µDMA request to clear. 0x7 Writing channel controller data. 0x8 Stalled 0x9 Done 0xA-0xF Undefined 3:1 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 710 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 MASTEN RO 0 Description Master Enable Status Value Description 0 The μDMA controller is disabled. 1 The μDMA controller is enabled. June 18, 2014 711 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 5: DMA Configuration (DMACFG), offset 0x004 The DMACFG register controls the configuration of the μDMA controller. DMA Configuration (DMACFG) Base 0x400F.F000 Offset 0x004 Type WO, reset 31 30 29 28 27 26 25 24 WO - WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 8 WO - WO - WO - WO - WO - WO - WO - 23 22 21 20 19 18 17 16 WO - WO - WO - WO - WO - WO - WO - WO - 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - reserved Type Reset reserved Type Reset WO - MASTEN WO - Bit/Field Name Type Reset Description 31:1 reserved WO - Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 MASTEN WO - Controller Master Enable Value Description 0 Disables the μDMA controller. 1 Enables μDMA controller. 712 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 6: DMA Channel Control Base Pointer (DMACTLBASE), offset 0x008 The DMACTLBASE register must be configured so that the base pointer points to a location in system memory. The amount of system memory that must be assigned to the μDMA controller depends on the number of μDMA channels used and whether the alternate channel control data structure is used. See “Channel Configuration” on page 683 for details about the Channel Control Table. The base address must be aligned on a 1024-byte boundary. This register cannot be read when the μDMA controller is in the reset state. DMA Channel Control Base Pointer (DMACTLBASE) Base 0x400F.F000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 ADDR Type Reset RW 0 RW 0 RW 0 15 14 13 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 ADDR Type Reset RW 0 RW 0 RW 0 reserved RW 0 RW 0 RW 0 RO 0 Bit/Field Name Type Reset 31:10 ADDR RW 0x0000.00 RO 0 RO 0 RO 0 RO 0 Description Channel Control Base Address This field contains the pointer to the base address of the channel control table. The base address must be 1024-byte aligned. 9:0 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 713 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 7: DMA Alternate Channel Control Base Pointer (DMAALTBASE), offset 0x00C The DMAALTBASE register returns the base address of the alternate channel control data. This register removes the necessity for application software to calculate the base address of the alternate channel control structures. This register cannot be read when the μDMA controller is in the reset state. DMA Alternate Channel Control Base Pointer (DMAALTBASE) Base 0x400F.F000 Offset 0x00C Type RO, reset 0x0000.0200 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 ADDR Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 ADDR Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type 31:0 ADDR RO RO 1 Reset RO 0 Description 0x0000.0200 Alternate Channel Address Pointer This field provides the base address of the alternate channel control structures. 714 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: DMA Channel Wait-on-Request Status (DMAWAITSTAT), offset 0x010 This read-only register indicates that the μDMA channel is waiting on a request. A peripheral can hold off the μDMA from performing a single request until the peripheral is ready for a burst request to enhance the μDMA performance. The use of this feature is dependent on the design of the peripheral and is not controllable by software in any way. This register cannot be read when the μDMA controller is in the reset state. DMA Channel Wait-on-Request Status (DMAWAITSTAT) Base 0x400F.F000 Offset 0x010 Type RO, reset 0x03C3.CF00 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WAITREQ[n] Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 15 14 13 12 11 10 9 RO 1 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 WAITREQ[n] Type Reset RO 1 RO 1 RO 0 RO 0 RO 1 RO 1 Bit/Field Name Type 31:0 WAITREQ[n] RO RO 1 Reset RO 1 RO 0 Description 0x03C3.CF00 Channel [n] Wait Status These bits provide the channel wait-on-request status. Bit 0 corresponds to channel 0. Value Description 0 The corresponding channel is not waiting on a request. 1 The corresponding channel is waiting on a request. June 18, 2014 715 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 9: DMA Channel Software Request (DMASWREQ), offset 0x014 Each bit of the DMASWREQ register represents the corresponding μDMA channel. Setting a bit generates a request for the specified μDMA channel. DMA Channel Software Request (DMASWREQ) Base 0x400F.F000 Offset 0x014 Type WO, reset 31 30 29 28 27 26 25 24 WO - WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 8 WO - WO - WO - WO - WO - WO - WO - WO - 23 22 21 20 19 18 17 16 WO - WO - WO - WO - WO - WO - WO - WO - 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - SWREQ[n] Type Reset SWREQ[n] Type Reset Bit/Field Name Type Reset 31:0 SWREQ[n] WO - WO - Description Channel [n] Software Request These bits generate software requests. Bit 0 corresponds to channel 0. Value Description 0 No request generated. 1 Generate a software request for the corresponding channel. These bits are automatically cleared when the software request has been completed. 716 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 10: DMA Channel Useburst Set (DMAUSEBURSTSET), offset 0x018 Each bit of the DMAUSEBURSTSET register represents the corresponding μDMA channel. Setting a bit disables the channel's single request input from generating requests, configuring the channel to only accept burst requests. Reading the register returns the status of USEBURST. If the amount of data to transfer is a multiple of the arbitration (burst) size, the corresponding SET[n] bit is cleared after completing the final transfer. If there are fewer items remaining to transfer than the arbitration (burst) size, the μDMA controller automatically clears the corresponding SET[n] bit, allowing the remaining items to transfer using single requests. In order to resume transfers using burst requests, the corresponding bit must be set again. A bit should not be set if the corresponding peripheral does not support the burst request model. Refer to “Request Types” on page 682 for more details about request types. DMA Channel Useburst Set (DMAUSEBURSTSET) Base 0x400F.F000 Offset 0x018 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 SET[n] Type Reset SET[n] Type Reset Bit/Field Name Type 31:0 SET[n] RW Reset Description 0x0000.0000 Channel [n] Useburst Set Value Description 0 μDMA channel [n] responds to single or burst requests. 1 μDMA channel [n] responds only to burst requests. Bit 0 corresponds to channel 0. This bit is automatically cleared as described above. A bit can also be manually cleared by setting the corresponding CLR[n] bit in the DMAUSEBURSTCLR register. June 18, 2014 717 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 11: DMA Channel Useburst Clear (DMAUSEBURSTCLR), offset 0x01C Each bit of the DMAUSEBURSTCLR register represents the corresponding μDMA channel. Setting a bit clears the corresponding SET[n] bit in the DMAUSEBURSTSET register. DMA Channel Useburst Clear (DMAUSEBURSTCLR) Base 0x400F.F000 Offset 0x01C Type WO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - CLR[n] Type Reset CLR[n] Type Reset Bit/Field Name Type Reset 31:0 CLR[n] WO - Description Channel [n] Useburst Clear Value Description 0 No effect. 1 Setting a bit clears the corresponding SET[n] bit in the DMAUSEBURSTSET register meaning that µDMA channel [n] responds to single and burst requests. 718 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 12: DMA Channel Request Mask Set (DMAREQMASKSET), offset 0x020 Each bit of the DMAREQMASKSET register represents the corresponding μDMA channel. Setting a bit disables μDMA requests for the channel. Reading the register returns the request mask status. When a μDMA channel's request is masked, that means the peripheral can no longer request μDMA transfers. The channel can then be used for software-initiated transfers. DMA Channel Request Mask Set (DMAREQMASKSET) Base 0x400F.F000 Offset 0x020 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 SET[n] Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 SET[n] Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type 31:0 SET[n] RW RW 0 Reset RW 0 Description 0x0000.0000 Channel [n] Request Mask Set Value Description 0 The peripheral associated with channel [n] is enabled to request μDMA transfers. 1 The peripheral associated with channel [n] is not able to request μDMA transfers. Channel [n] may be used for software-initiated transfers. Bit 0 corresponds to channel 0. A bit can only be cleared by setting the corresponding CLR[n] bit in the DMAREQMASKCLR register. June 18, 2014 719 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 13: DMA Channel Request Mask Clear (DMAREQMASKCLR), offset 0x024 Each bit of the DMAREQMASKCLR register represents the corresponding μDMA channel. Setting a bit clears the corresponding SET[n] bit in the DMAREQMASKSET register. DMA Channel Request Mask Clear (DMAREQMASKCLR) Base 0x400F.F000 Offset 0x024 Type WO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO - WO - WO - WO - WO - WO - WO - WO - 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - WO - CLR[n] Type Reset WO - WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 8 CLR[n] Type Reset WO - WO - WO - WO - WO - WO - WO - Bit/Field Name Type Reset 31:0 CLR[n] WO - WO - Description Channel [n] Request Mask Clear Value Description 0 No effect. 1 Setting a bit clears the corresponding SET[n] bit in the DMAREQMASKSET register meaning that the peripheral associated with channel [n] is enabled to request μDMA transfers. 720 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 14: DMA Channel Enable Set (DMAENASET), offset 0x028 Each bit of the DMAENASET register represents the corresponding µDMA channel. Setting a bit enables the corresponding µDMA channel. Reading the register returns the enable status of the channels. If a channel is enabled but the request mask is set (DMAREQMASKSET), then the channel can be used for software-initiated transfers. DMA Channel Enable Set (DMAENASET) Base 0x400F.F000 Offset 0x028 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 SET[n] Type Reset SET[n] Type Reset Bit/Field Name Type 31:0 SET[n] RW Reset Description 0x0000.0000 Channel [n] Enable Set Value Description 0 µDMA Channel [n] is disabled. 1 µDMA Channel [n] is enabled. Bit 0 corresponds to channel 0. A bit can only be cleared by setting the corresponding CLR[n] bit in the DMAENACLR register or when the end of a µDMA transfer occurs. June 18, 2014 721 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 15: DMA Channel Enable Clear (DMAENACLR), offset 0x02C Each bit of the DMAENACLR register represents the corresponding µDMA channel. Setting a bit clears the corresponding SET[n] bit in the DMAENASET register. DMA Channel Enable Clear (DMAENACLR) Base 0x400F.F000 Offset 0x02C Type WO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - CLR[n] Type Reset CLR[n] Type Reset Bit/Field Name Type Reset 31:0 CLR[n] WO - Description Clear Channel [n] Enable Clear Value Description 0 No effect. 1 Setting a bit clears the corresponding SET[n] bit in the DMAENASET register meaning that channel [n] is disabled for μDMA transfers. Note: The controller disables a channel when it completes the μDMA cycle. 722 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 16: DMA Channel Primary Alternate Set (DMAALTSET), offset 0x030 Each bit of the DMAALTSET register represents the corresponding µDMA channel. Setting a bit configures the µDMA channel to use the alternate control data structure. Reading the register returns the status of which control data structure is in use for the corresponding µDMA channel. DMA Channel Primary Alternate Set (DMAALTSET) Base 0x400F.F000 Offset 0x030 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 SET[n] Type Reset SET[n] Type Reset Bit/Field Name Type 31:0 SET[n] RW Reset Description 0x0000.0000 Channel [n] Alternate Set Value Description 0 µDMA channel [n] is using the primary control structure. 1 µDMA channel [n] is using the alternate control structure. Bit 0 corresponds to channel 0. A bit can only be cleared by setting the corresponding CLR[n] bit in the DMAALTCLR register. Note: For Ping-Pong and Scatter-Gather cycle types, the µDMA controller automatically sets these bits to select the alternate channel control data structure. June 18, 2014 723 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 17: DMA Channel Primary Alternate Clear (DMAALTCLR), offset 0x034 Each bit of the DMAALTCLR register represents the corresponding μDMA channel. Setting a bit clears the corresponding SET[n] bit in the DMAALTSET register. DMA Channel Primary Alternate Clear (DMAALTCLR) Base 0x400F.F000 Offset 0x034 Type WO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO - WO - WO - WO - WO - WO - WO - WO - 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - WO - CLR[n] Type Reset WO - WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 8 CLR[n] Type Reset WO - WO - WO - WO - WO - WO - WO - Bit/Field Name Type Reset 31:0 CLR[n] WO - WO - Description Channel [n] Alternate Clear Value Description 0 No effect. 1 Setting a bit clears the corresponding SET[n] bit in the DMAALTSET register meaning that channel [n] is using the primary control structure. Note: For Ping-Pong and Scatter-Gather cycle types, the µDMA controller automatically sets these bits to select the alternate channel control data structure. 724 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 18: DMA Channel Priority Set (DMAPRIOSET), offset 0x038 Each bit of the DMAPRIOSET register represents the corresponding µDMA channel. Setting a bit configures the µDMA channel to have a high priority level. Reading the register returns the status of the channel priority mask. DMA Channel Priority Set (DMAPRIOSET) Base 0x400F.F000 Offset 0x038 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 SET[n] Type Reset SET[n] Type Reset Bit/Field Name Type 31:0 SET[n] RW Reset Description 0x0000.0000 Channel [n] Priority Set Value Description 0 µDMA channel [n] is using the default priority level. 1 µDMA channel [n] is using a high priority level. Bit 0 corresponds to channel 0. A bit can only be cleared by setting the corresponding CLR[n] bit in the DMAPRIOCLR register. June 18, 2014 725 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 19: DMA Channel Priority Clear (DMAPRIOCLR), offset 0x03C Each bit of the DMAPRIOCLR register represents the corresponding µDMA channel. Setting a bit clears the corresponding SET[n] bit in the DMAPRIOSET register. DMA Channel Priority Clear (DMAPRIOCLR) Base 0x400F.F000 Offset 0x03C Type WO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - WO - CLR[n] Type Reset CLR[n] Type Reset Bit/Field Name Type Reset 31:0 CLR[n] WO - Description Channel [n] Priority Clear Value Description 0 No effect. 1 Setting a bit clears the corresponding SET[n] bit in the DMAPRIOSET register meaning that channel [n] is using the default priority level. 726 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 20: DMA Bus Error Clear (DMAERRCLR), offset 0x04C The DMAERRCLR register is used to read and clear the µDMA bus error status. The error status is set if the μDMA controller encountered a bus error while performing a transfer. If a bus error occurs on a channel, that channel is automatically disabled by the μDMA controller. The other channels are unaffected. DMA Bus Error Clear (DMAERRCLR) Base 0x400F.F000 Offset 0x04C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 ERRCLR RW1C 0 RO 0 ERRCLR RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA Bus Error Status Value Description 0 No bus error is pending. 1 A bus error is pending. This bit is cleared by writing a 1 to it. June 18, 2014 727 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 21: DMA Channel Assignment (DMACHASGN), offset 0x500 Each bit of the DMACHASGN register represents the corresponding µDMA channel. Setting a bit selects the secondary channel assignment as specified in Table 9-1 on page 680. Note: This register is provided to support legacy software. New software should use the DMACHMAPn registers. If a bit is clear in this register, the corresponding field in the DMACHMAPn registers is configured to 0x0. If a bit is set in this register, the corresponding field is configured to 0x1. If this register is read, a bit reads as 0 if the corresponding DMACHMAPn register field value is equal to 0, otherwise it reads as 1 if the corresponding DMACHMAPn register field value is not equal to 0. DMA Channel Assignment (DMACHASGN) Base 0x400F.F000 Offset 0x500 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 CHASGN[n] Type Reset RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW - RW - RW - RW - RW - RW - RW - CHASGN[n] Type Reset RW - RW - RW - RW - RW - RW - RW - Bit/Field Name Type Reset 31:0 CHASGN[n] RW - RW - RW - Description Channel [n] Assignment Select Value Description 0 Use the primary channel assignment. 1 Use the secondary channel assignment. 728 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 22: DMA Channel Map Select 0 (DMACHMAP0), offset 0x510 Each 4-bit field of the DMACHMAP0 register configures the μDMA channel assignment as specified in Table 9-1 on page 680. Note: To support legacy software which uses the DMA Channel Assignment (DMACHASGN) register, a value of 0x0 is equivalent to a DMACHASGN bit being clear, and a value of 0x1 is equivalent to a DMACHASGN bit being set. DMA Channel Map Select 0 (DMACHMAP0) Base 0x400F.F000 Offset 0x510 Type RW, reset 0x0000.0000 31 30 29 28 27 26 CH7SEL Type Reset 24 23 22 21 20 19 18 CH5SEL 17 16 CH4SEL RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 CH3SEL Type Reset 25 CH6SEL RW 0 RW 0 CH2SEL RW 0 RW 0 RW 0 RW 0 RW 0 CH1SEL RW 0 RW 0 RW 0 RW 0 CH0SEL RW 0 Bit/Field Name Type Reset Description 31:28 CH7SEL RW 0x00 μDMA Channel 7 Source Select RW 0 RW 0 See Table 9-1 on page 680 for channel assignments. 27:24 CH6SEL RW 0x00 μDMA Channel 6 Source Select See Table 9-1 on page 680 for channel assignments. 23:20 CH5SEL RW 0x00 μDMA Channel 5 Source Select See Table 9-1 on page 680 for channel assignments. 19:16 CH4SEL RW 0x00 μDMA Channel 4 Source Select See Table 9-1 on page 680 for channel assignments. 15:12 CH3SEL RW 0x00 μDMA Channel 3 Source Select See Table 9-1 on page 680 for channel assignments. 11:8 CH2SEL RW 0x00 μDMA Channel 2 Source Select See Table 9-1 on page 680 for channel assignments. 7:4 CH1SEL RW 0x00 μDMA Channel 1 Source Select See Table 9-1 on page 680 for channel assignments. 3:0 CH0SEL RW 0x00 μDMA Channel 0 Source Select See Table 9-1 on page 680 for channel assignments. June 18, 2014 729 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 23: DMA Channel Map Select 1 (DMACHMAP1), offset 0x514 Each 4-bit field of the DMACHMAP1 register configures the μDMA channel assignment as specified in Table 9-1 on page 680. Note: To support legacy software which uses the DMA Channel Assignment (DMACHASGN) register, a value of 0x0 is equivalent to a DMACHASGN bit being clear, and a value of 0x1 is equivalent to a DMACHASGN bit being set. DMA Channel Map Select 1 (DMACHMAP1) Base 0x400F.F000 Offset 0x514 Type RW, reset 0x0000.0000 31 30 29 28 27 26 CH15SEL Type Reset 24 23 22 21 20 19 CH13SEL 18 17 16 CH12SEL RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 CH11SEL Type Reset 25 CH14SEL RW 0 RW 0 CH10SEL RW 0 RW 0 RW 0 RW 0 RW 0 CH9SEL RW 0 RW 0 RW 0 RW 0 CH8SEL RW 0 Bit/Field Name Type Reset Description 31:28 CH15SEL RW 0x00 μDMA Channel 15 Source Select RW 0 RW 0 See Table 9-1 on page 680 for channel assignments. 27:24 CH14SEL RW 0x00 μDMA Channel 14 Source Select See Table 9-1 on page 680 for channel assignments. 23:20 CH13SEL RW 0x00 μDMA Channel 13 Source Select See Table 9-1 on page 680 for channel assignments. 19:16 CH12SEL RW 0x00 μDMA Channel 12 Source Select See Table 9-1 on page 680 for channel assignments. 15:12 CH11SEL RW 0x00 μDMA Channel 11 Source Select See Table 9-1 on page 680 for channel assignments. 11:8 CH10SEL RW 0x00 μDMA Channel 10 Source Select See Table 9-1 on page 680 for channel assignments. 7:4 CH9SEL RW 0x00 μDMA Channel 9 Source Select See Table 9-1 on page 680 for channel assignments. 3:0 CH8SEL RW 0x00 μDMA Channel 8 Source Select See Table 9-1 on page 680 for channel assignments. 730 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 24: DMA Channel Map Select 2 (DMACHMAP2), offset 0x518 Each 4-bit field of the DMACHMAP2 register configures the μDMA channel assignment as specified in Table 9-1 on page 680. Note: To support legacy software which uses the DMA Channel Assignment (DMACHASGN) register, a value of 0x0 is equivalent to a DMACHASGN bit being clear, and a value of 0x1 is equivalent to a DMACHASGN bit being set. DMA Channel Map Select 2 (DMACHMAP2) Base 0x400F.F000 Offset 0x518 Type RW, reset 0x0000.0000 31 30 29 28 27 26 CH23SEL Type Reset 24 23 22 21 20 19 CH21SEL 18 17 16 CH20SEL RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CH19SEL Type Reset 25 CH22SEL RW 0 RW 0 CH18SEL RW 0 RW 0 RW 0 RW 0 RW 0 CH17SEL RW 0 RW 0 RW 0 RW 0 CH16SEL RW 0 Bit/Field Name Type Reset Description 31:28 CH23SEL RW 0x00 μDMA Channel 23 Source Select RW 0 RW 0 RW 0 RW 0 See Table 9-1 on page 680 for channel assignments. 27:24 CH22SEL RW 0x00 μDMA Channel 22 Source Select See Table 9-1 on page 680 for channel assignments. 23:20 CH21SEL RW 0x00 μDMA Channel 21 Source Select See Table 9-1 on page 680 for channel assignments. 19:16 CH20SEL RW 0x00 μDMA Channel 20 Source Select See Table 9-1 on page 680 for channel assignments. 15:12 CH19SEL RW 0x00 μDMA Channel 19 Source Select See Table 9-1 on page 680 for channel assignments. 11:8 CH18SEL RW 0x00 μDMA Channel 18 Source Select See Table 9-1 on page 680 for channel assignments. 7:4 CH17SEL RW 0x00 μDMA Channel 17 Source Select See Table 9-1 on page 680 for channel assignments. 3:0 CH16SEL RW 0x00 μDMA Channel 16 Source Select See Table 9-1 on page 680 for channel assignments. June 18, 2014 731 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 25: DMA Channel Map Select 3 (DMACHMAP3), offset 0x51C Each 4-bit field of the DMACHMAP3 register configures the μDMA channel assignment as specified in Table 9-1 on page 680. Note: To support legacy software which uses the DMA Channel Assignment (DMACHASGN) register, a value of 0x0 is equivalent to a DMACHASGN bit being clear, and a value of 0x1 is equivalent to a DMACHASGN bit being set. DMA Channel Map Select 3 (DMACHMAP3) Base 0x400F.F000 Offset 0x51C Type RW, reset 0x0000.0000 31 30 29 28 27 26 CH31SEL Type Reset 24 23 22 21 20 19 CH29SEL 18 17 16 CH28SEL RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CH27SEL Type Reset 25 CH30SEL RW 0 RW 0 CH26SEL RW 0 RW 0 RW 0 RW 0 RW 0 CH25SEL RW 0 RW 0 RW 0 RW 0 CH24SEL RW 0 Bit/Field Name Type Reset Description 31:28 CH31SEL RW 0x00 μDMA Channel 31 Source Select RW 0 RW 0 RW 0 RW 0 See Table 9-1 on page 680 for channel assignments. 27:24 CH30SEL RW 0x00 μDMA Channel 30 Source Select See Table 9-1 on page 680 for channel assignments. 23:20 CH29SEL RW 0x00 μDMA Channel 29 Source Select See Table 9-1 on page 680 for channel assignments. 19:16 CH28SEL RW 0x00 μDMA Channel 28 Source Select See Table 9-1 on page 680 for channel assignments. 15:12 CH27SEL RW 0x00 μDMA Channel 27 Source Select See Table 9-1 on page 680 for channel assignments. 11:8 CH26SEL RW 0x00 μDMA Channel 26 Source Select See Table 9-1 on page 680 for channel assignments. 7:4 CH25SEL RW 0x00 μDMA Channel 25 Source Select See Table 9-1 on page 680 for channel assignments. 3:0 CH24SEL RW 0x00 μDMA Channel 24 Source Select See Table 9-1 on page 680 for channel assignments. 732 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 26: DMA Peripheral Identification 0 (DMAPeriphID0), offset 0xFE0 The DMAPeriphIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA Peripheral Identification 0 (DMAPeriphID0) Base 0x400F.F000 Offset 0xFE0 Type RO, reset 0x0000.0030 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID0 RO 0x30 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA Peripheral ID Register [7:0] Can be used by software to identify the presence of this peripheral. June 18, 2014 733 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 27: DMA Peripheral Identification 1 (DMAPeriphID1), offset 0xFE4 The DMAPeriphIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA Peripheral Identification 1 (DMAPeriphID1) Base 0x400F.F000 Offset 0xFE4 Type RO, reset 0x0000.00B2 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 0 RO 1 RO 1 RO 0 RO 0 RO 1 RO 0 reserved Type Reset reserved Type Reset PID1 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID1 RO 0xB2 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA Peripheral ID Register [15:8] Can be used by software to identify the presence of this peripheral. 734 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 28: DMA Peripheral Identification 2 (DMAPeriphID2), offset 0xFE8 The DMAPeriphIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA Peripheral Identification 2 (DMAPeriphID2) Base 0x400F.F000 Offset 0xFE8 Type RO, reset 0x0000.000B 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 0 RO 1 RO 1 reserved Type Reset reserved Type Reset PID2 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID2 RO 0x0B Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA Peripheral ID Register [23:16] Can be used by software to identify the presence of this peripheral. June 18, 2014 735 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 29: DMA Peripheral Identification 3 (DMAPeriphID3), offset 0xFEC The DMAPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. DMA Peripheral Identification 3 (DMAPeriphID3) Base 0x400F.F000 Offset 0xFEC Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID3 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID3 RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA Peripheral ID Register [31:24] Can be used by software to identify the presence of this peripheral. 736 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 30: DMA Peripheral Identification 4 (DMAPeriphID4), offset 0xFD0 The DMAPeriphIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA Peripheral Identification 4 (DMAPeriphID4) Base 0x400F.F000 Offset 0xFD0 Type RO, reset 0x0000.0004 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 0 RO 0 reserved Type Reset reserved Type Reset PID4 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID4 RO 0x04 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA Peripheral ID Register Can be used by software to identify the presence of this peripheral. June 18, 2014 737 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 31: DMA PrimeCell Identification 0 (DMAPCellID0), offset 0xFF0 The DMAPCellIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA PrimeCell Identification 0 (DMAPCellID0) Base 0x400F.F000 Offset 0xFF0 Type RO, reset 0x0000.000D 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 1 reserved Type Reset reserved Type Reset CID0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID0 RO 0x0D Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA PrimeCell ID Register [7:0] Provides software a standard cross-peripheral identification system. 738 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 32: DMA PrimeCell Identification 1 (DMAPCellID1), offset 0xFF4 The DMAPCellIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA PrimeCell Identification 1 (DMAPCellID1) Base 0x400F.F000 Offset 0xFF4 Type RO, reset 0x0000.00F0 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 1 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset CID1 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID1 RO 0xF0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA PrimeCell ID Register [15:8] Provides software a standard cross-peripheral identification system. June 18, 2014 739 Texas Instruments-Production Data Micro Direct Memory Access (μDMA) Register 33: DMA PrimeCell Identification 2 (DMAPCellID2), offset 0xFF8 The DMAPCellIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA PrimeCell Identification 2 (DMAPCellID2) Base 0x400F.F000 Offset 0xFF8 Type RO, reset 0x0000.0005 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 0 RO 1 reserved Type Reset reserved Type Reset CID2 RO 0 Bit/Field Name Type Reset Description 31:8 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7:0 CID2 RO 0x05 μDMA PrimeCell ID Register [23:16] Provides software a standard cross-peripheral identification system. 740 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 34: DMA PrimeCell Identification 3 (DMAPCellID3), offset 0xFFC The DMAPCellIDn registers are hard-coded, and the fields within the registers determine the reset values. DMA PrimeCell Identification 3 (DMAPCellID3) Base 0x400F.F000 Offset 0xFFC Type RO, reset 0x0000.00B1 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 RO 1 reserved Type Reset reserved Type Reset CID3 RO 0 Bit/Field Name Type Reset Description 31:8 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7:0 CID3 RO 0xB1 μDMA PrimeCell ID Register [31:24] Provides software a standard cross-peripheral identification system. June 18, 2014 741 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) 10 General-Purpose Input/Outputs (GPIOs) The GPIO module is composed of 15 physical GPIO blocks, each corresponding to an individual GPIO port (Port A, Port B, Port C, Port D, Port E, Port F, Port G, Port H, Port J, Port K, Port L, Port M, Port N, Port P, Port Q). The GPIO module supports up to 90 programmable input/output pins, depending on the peripherals being used. The GPIO module has the following features: ■ Up to 90 GPIOs, depending on configuration ■ Highly flexible pin muxing allows use as GPIO or one of several peripheral functions ■ 3.3-V-tolerant in input configuration ■ Advanced High Performance Bus accesses all ports: – Ports A-H and J; Ports K-N and P-Q ■ Fast toggle capable of a change every clock cycle for ports on AHB ■ Programmable control for GPIO interrupts – Interrupt generation masking – Edge-triggered on rising, falling, or both – Level-sensitive on High or Low values – Per-pin interrupts available on Port P and Port Q ■ Bit masking in both read and write operations through address lines ■ Can be used to initiate an ADC sample sequence or a μDMA transfer ■ Pin state can be retained during Hibernation mode; pins on port P can be programmed to wake on level in Hibernation mode ■ Pins configured as digital inputs are Schmitt-triggered ■ Programmable control for GPIO pad configuration – Weak pull-up or pull-down resistors – 2-mA, 4-mA, 6-mA, 8-mA, 10-mA and 12-mA pad drive for digital communication; up to four pads can sink 18-mA for high-current applications – Slew rate control for 8-mA, 10-mA and 12-mA pad drive – Open drain enables – Digital input enables 742 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 10.1 Signal Description GPIO signals have alternate hardware functions. The following table lists the GPIO pins and their analog and digital alternate functions. The digital alternate hardware functions are enabled by setting the appropriate bit in the GPIO Alternate Function Select (GPIOAFSEL) and GPIODEN registers and configuring the PMCx bit field in the GPIO Port Control (GPIOPCTL) register to the numeric encoding shown in the table below. Analog signals in the table below are also 3.3-V tolerant and are configured by clearing the DEN bit in the GPIO Digital Enable (GPIODEN) register. The AINx analog signals have internal circuitry to protect them from voltages over VDD (up to the maximum specified in Table 27-1 on page 1818), but analog performance specifications are only guaranteed if the input signal swing at the I/O pad is kept inside the range 0 V < VIN < VDD. Note that each pin must be programmed individually; no type of grouping is implied by the columns in the table. Table entries that are shaded gray are the default values for the corresponding GPIO pin. Important: The table below shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 10-1. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD PD[7] GPIO PE[7] GPIO GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware signals including the GPIO pins that can function as JTAG/SWD signals and the NMI signal. The commit control process must be followed for these pins, even if they are programmed as alternate functions other than JTAG/SWD or NMI; see “Commit Control” on page 752. Note: If the device fails initialization during reset, the hardware toggles the TDO output as an indication of failure. Thus, during board layout, designers should not designate the TDO pin as a GPIO in sensitive applications where the possibility of toggling could affect the design. Table 10-2. GPIO Pins and Alternate Functions (128TQFP) b IO Pin Analog or Special a Function Digital Function (GPIOPCTL PMCx Bit Field Encoding) PA0 33 - U0Rx I2C9SCL T0CCP0 - - - CAN0Rx - - - - - PA1 34 - U0Tx I2C9SDA T0CCP1 - - - CAN0Tx - - - - - PA2 35 - U4Rx I2C8SCL T1CCP0 - - - - - - - - SSI0Clk PA3 36 - U4Tx I2C8SDA T1CCP1 - - - - - - - - SSI0Fss PA4 37 - U3Rx I2C7SCL T2CCP0 - - - - - - - - SSI0XDAT0 1 2 3 4 5 6 7 8 11 13 14 15 June 18, 2014 743 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Table 10-2. GPIO Pins and Alternate Functions (128TQFP) (continued) b IO Pin Analog or Special a Function Digital Function (GPIOPCTL PMCx Bit Field Encoding) PA5 38 - U3Tx I2C7SDA T2CCP1 - - - - - - - - SSI0XDAT1 PA6 40 - U2Rx I2C6SCL T3CCP0 - USB0EPEN - - - - SSI0XDAT2 - EPI0S8 PA7 41 - U2Tx I2C6SDA T3CCP1 - USB0PFLT - - - USB0EPEN SSI0XDAT3 - EPI0S9 PB0 95 USB0ID U1Rx I2C5SCL T4CCP0 - - - CAN1Rx - - - - - PB1 96 USB0VBUS U1Tx I2C5SDA T4CCP1 - - - CAN1Tx - - - - - PB2 91 - - I2C0SCL T5CCP0 - - - - - - - USB0STP EPI0S27 PB3 92 - - I2C0SDA T5CCP1 - - - - - - - USB0CLK EPI0S28 PB4 121 AIN10 U0CTS I2C5SCL - - - - - - - - - SSI1Fss PB5 120 AIN11 U0RTS I2C5SDA - - - - - - - - - SSI1Clk PC0 100 - - - - - - - - - - - - - - - - - - - - - - - 1 2 3 4 5 6 7 8 11 13 14 15 TCK SWCLK PC1 99 - TMS SWDIO PC2 98 - TDI - - - - - - - - - - - PC3 97 - TDO SWO - - - - - - - - - - - PC4 25 C1- U7Rx - - - - - - - - - - EPI0S7 PC5 24 C1+ U7Tx - - - - - RTCCLK - - - - EPI0S6 PC6 23 C0+ U5Rx - - - - - - - - - - EPI0S5 PC7 22 C0- U5Tx - - - - - - - - - - EPI0S4 PD0 1 AIN15 - I2C7SCL T0CCP0 - C0o - - - - - - SSI2XDAT1 PD1 2 AIN14 - I2C7SDA T0CCP1 - C1o - - - - - - SSI2XDAT0 PD2 3 AIN13 - I2C8SCL T1CCP0 - C2o - - - - - - SSI2Fss PD3 4 AIN12 - I2C8SDA T1CCP1 - - - - - - - - SSI2Clk PD4 125 AIN7 U2Rx - T3CCP0 - - - - - - - - SSI1XDAT2 PD5 126 AIN6 U2Tx - T3CCP1 - - - - - - - - SSI1XDAT3 PD6 127 AIN5 U2RTS - T4CCP0 - USB0EPEN - - - - - - SSI2XDAT3 PD7 128 AIN4 U2CTS - T4CCP1 - USB0PFLT - - NMI - - - SSI2XDAT2 PE0 15 AIN3 U1RTS - - - - - - - - - - - PE1 14 AIN2 U1DSR - - - - - - - - - - - PE2 13 AIN1 U1DCD - - - - - - - - - - - PE3 12 AIN0 U1DTR - - - - - - - - - - - PE4 123 AIN9 U1RI - - - - - - - - - - SSI1XDAT0 PE5 124 AIN8 - - - - - - - - - - - SSI1XDAT1 PF0 42 - - - - - EN0LED0 M0PWM0 - - - - SSI3XDAT1 TRD2 PF1 43 - - - - - EN0LED2 M0PWM1 - - - - SSI3XDAT0 TRD1 744 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 10-2. GPIO Pins and Alternate Functions (128TQFP) (continued) b IO Pin Analog or Special a Function Digital Function (GPIOPCTL PMCx Bit Field Encoding) PF2 44 - - - - - - M0PWM2 - - - - SSI3Fss TRD0 PF3 45 - - - - - - M0PWM3 - - - - SSI3Clk TRCLK PF4 46 - - - - - EN0LED1 M0FAULT0 - - - - SSI3XDAT2 TRD3 PG0 49 - - I2C1SCL - - EN0PPS M0PWM4 - - - - - EPI0S11 PG1 50 - - I2C1SDA - - - M0PWM5 - - - - - EPI0S10 PH0 29 - U0RTS - - - - - - - - - - EPI0S0 PH1 30 - U0CTS - - - - - - - - - - EPI0S1 PH2 31 - U0DCD - - - - - - - - - - EPI0S2 PH3 32 - U0DSR - - - - - - - - - - EPI0S3 PJ0 116 - U3Rx - - - EN0PPS - - - - - - - PJ1 117 - U3Tx - - - - - - - - - - - PK0 18 AIN16 U4Rx - - - - - - - - - - EPI0S0 PK1 19 AIN17 U4Tx - - - - - - - - - - EPI0S1 PK2 20 AIN18 U4RTS - - - - - - - - - - EPI0S2 PK3 21 AIN19 U4CTS - - - - - - - - - - EPI0S3 PK4 63 - - I2C3SCL - - EN0LED0 M0PWM6 - - - - - EPI0S32 PK5 62 - - I2C3SDA - - EN0LED2 M0PWM7 - - - - - EPI0S31 PK6 61 - - I2C4SCL - - EN0LED1 M0FAULT1 - - - - - EPI0S25 PK7 60 - U0RI I2C4SDA - - RTCCLK M0FAULT2 - - - - - EPI0S24 PL0 81 - - I2C2SDA - - - M0FAULT3 - - - - USB0D0 EPI0S16 PL1 82 - - I2C2SCL - - - PhA0 - - - - USB0D1 EPI0S17 PL2 83 - - - - - C0o PhB0 - - - - USB0D2 EPI0S18 PL3 84 - - - - - C1o IDX0 - - - - USB0D3 EPI0S19 PL4 85 - - - T0CCP0 - - - - - - - USB0D4 EPI0S26 PL5 86 - - - T0CCP1 - - - - - - - USB0D5 EPI0S33 PL6 94 USB0DP - - T1CCP0 - - - - - - - - - PL7 93 USB0DM - - T1CCP1 - - - - - - - - - PM0 78 - - - T2CCP0 - - - - - - - - EPI0S15 PM1 77 - - - T2CCP1 - - - - - - - - EPI0S14 PM2 76 - - - T3CCP0 - - - - - - - - EPI0S13 PM3 75 - - - T3CCP1 - - - - - - - - EPI0S12 PM4 74 TMPR3 U0CTS - T4CCP0 - - - - - - - - - PM5 73 TMPR2 U0DCD - T4CCP1 - - - - - - - - - PM6 72 TMPR1 U0DSR - T5CCP0 - - - - - - - - - 1 2 3 4 5 6 7 8 11 13 14 15 June 18, 2014 745 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Table 10-2. GPIO Pins and Alternate Functions (128TQFP) (continued) b IO Pin Analog or Special a Function Digital Function (GPIOPCTL PMCx Bit Field Encoding) PM7 71 TMPR0 U0RI - T5CCP1 - - - - - - - - - PN0 107 - U1RTS - - - - - - - - - - - PN1 108 - U1CTS - - - - - - - - - - - PN2 109 - U1DCD U2RTS - - - - - - - - - EPI0S29 PN3 110 - U1DSR U2CTS - - - - - - - - - EPI0S30 PN4 111 - U1DTR U3RTS I2C2SDA - - - - - - - - EPI0S34 PN5 112 - U1RI U3CTS I2C2SCL - - - - - - - - EPI0S35 PP0 118 C2+ U6Rx - - - - - - - - - - SSI3XDAT2 PP1 119 C2- U6Tx - - - - - - - - - - SSI3XDAT3 PP2 103 - U0DTR - - - - - - - - - USB0NXT EPI0S29 PP3 104 - U1CTS U0DCD - - - - RTCCLK - - - USB0DIR EPI0S30 PP4 105 - U3RTS U0DSR - - - - - - - - USB0D7 - PP5 106 - U3CTS I2C2SCL - - - - - - - - USB0D6 - PQ0 5 - - - - - - - - - - - SSI3Clk EPI0S20 PQ1 6 - - - - - - - - - - - SSI3Fss EPI0S21 PQ2 11 - - - - - - - - - - - SSI3XDAT0 EPI0S22 PQ3 27 - - - - - - - - - - - SSI3XDAT1 EPI0S23 PQ4 102 - U1Rx - - - - - DIVSCLK - - - - - 1 2 3 4 5 6 7 8 11 13 14 15 a. The TMPRn signals are digital signals enabled and configured by the Hibernation module. All other signals listed in this column are analog signals. b. The digital signals that are shaded gray are the power-on default values for the corresponding GPIO pin. Encodings 9, 10, and 12 are not used on this device. 10.2 Pad Capabilities There are two main types of pads provided on the device: ■ Fast GPIO pads: These pads provide variable, programmable drive strength and optimized voltage output levels. ■ Slow GPIO pads: These pads provide 2-mA drive strength and are designed to be sensitive to voltage inputs. The following GPIOs port pins are designed with Slow GPIO Pads: – PJ1 Please refer to“Recommended GPIO Operating Characteristics” on page 1820 for details on the GPIO operating conditions for these two different pad types. Note: Port pins PL6 and PL7 operate as Fast GPIO pads, but have 4-mA drive capability only. GPIO register controls for drive strength, slew rate and open drain have no effect on these pins. The registers which have no effect are as follows: GPIODR2R, GPIODR4R, GPIODR8R, GPIODR12R, GPIOSLR, and GPIOODR. 746 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Note: 10.3 Port pins PM[7:4] operate as Fast GPIO pads but support only 2-, 4-, 6-, and 8-mA drive capability. 10- and 12-mA drive are not supported. All standard GPIO register controls, except for the GPIODR12R register, apply to these port pins. Functional Description Each GPIO port is a separate hardware instantiation of the same physical block (see Figure 10-1 on page 747 and Figure 10-2 on page 748). The TM4C1294NCPDT microcontroller contains 15 ports and thus 15 of these physical GPIO blocks. Note that not all pins are implemented on every block. Some GPIO pins can function as I/O signals for the on-chip peripheral modules. For information on which GPIO pins are used for alternate hardware functions, refer to Table 26-5 on page 1808. Figure 10-1. Digital I/O Pads Mode Control GPIOAFSEL GPIOADCCTL GPIODMACTL Commit Control GPIOLOCK GPIOCR Port Control GPIOPCTL Periph 1 DEMUX Alternate Input Alternate Output Alternate Output Enable MUX Periph 0 Pad Input Periph n GPIO Output GPIO Output Enable Interrupt Control Pad Control GPIOIS GPIOIBE GPIOIEV GPIOIM GPIORIS GPIOMIS GPIOICR GPIOSI GPIODR2R GPIODR4R GPIODR8R GPIOSLR GPIOPUR GPIOPDR GPIOODR GPIODEN GPIODR12R GPIOAMSEL MUX GPIODATA GPIODIR Interrupt MUX GPIO Input Data Control Pad Output Digital I/O Pad Package I/O Pin Pad Output Enable Identification Registers GPIOPeriphID0 GPIOPeriphID1 GPIOPeriphID2 GPIOPeriphID3 GPIOPeriphID4 GPIOPeriphID5 GPIOPeriphID6 GPIOPeriphID7 GPIOPCellID0 GPIOPCellID1 GPIOPCellID2 GPIOPCellID3 June 18, 2014 747 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Figure 10-2. Analog/Digital I/O Pads Commit Control GPIOLOCK GPIOCR Port Control GPIOPCTL Mode Control GPIOAFSEL GPIOAMSEL GPIOADCCTL GPIODMACTL Periph 1 DEMUX Alternate Input Alternate Output Alternate Output Enable MUX Periph 0 Pad Input Periph n MUX MUX Data Control Pad Output Pad Output Enable Analog/Digital I/O Pad Package I/O Pin GPIO Input GPIO Output GPIODATA GPIODIR Interrupt GPIO Output Enable Interrupt Control GPIOIS GPIOIBE GPIOIEV GPIOIM GPIORIS GPIOMIS GPIOICR GPIOSI Pad Control GPIODR2R GPIODR4R GPIODR8R GPIOSLR GPIOPUR GPIOPDR GPIOODR GPIODEN GPIOAMSEL GPIODR12R Analog Circuitry Identification Registers GPIOPeriphID0 GPIOPeriphID1 GPIOPeriphID2 GPIOPeriphID3 10.3.1 GPIOPeriphID4 GPIOPeriphID5 GPIOPeriphID6 GPIOPeriphID7 GPIOPCellID0 GPIOPCellID1 GPIOPCellID2 GPIOPCellID3 ADC (for GPIO pins that connect to the ADC input MUX) Isolation Circuit Data Control The data control registers allow software to configure the operational modes of the GPIOs. The data direction register configures the GPIO as an input or an output while the data register either captures incoming data or drives it out to the pads. Caution – It is possible to create a software sequence that prevents the debugger from connecting to the TM4C1294NCPDT microcontroller. If the program code loaded into flash immediately changes the JTAG pins to their GPIO functionality, the debugger may not have enough time to connect and halt the controller before the JTAG pin functionality switches. As a result, the debugger may be locked out of the part. This issue can be avoided with a software routine that restores JTAG functionality based on an external or software trigger. In the case that the software routine is not implemented and the device is locked out of the part, this issue can be solved by using the TM4C1294NCPDT Flash Programmer "Unlock" feature. Please refer to LMFLASHPROGRAMMER on the TI web for more information. 748 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 10.3.1.1 Data Direction Operation The GPIO Direction (GPIODIR) register (see page 760) is used to configure each individual pin as an input or output. When the data direction bit is cleared, the GPIO is configured as an input, and the corresponding data register bit captures and stores the value on the GPIO port. When the data direction bit is set, the GPIO is configured as an output, and the corresponding data register bit is driven out on the GPIO port. 10.3.1.2 Data Register Operation To aid in the efficiency of software, the GPIO ports allow for the modification of individual bits in the GPIO Data (GPIODATA) register (see page 759) by using bits [9:2] of the address bus as a mask. In this manner, software drivers can modify individual GPIO pins in a single instruction without affecting the state of the other pins. This method is more efficient than the conventional method of performing a read-modify-write operation to set or clear an individual GPIO pin. To implement this feature, the GPIODATA register covers 256 locations in the memory map. During a write, if the address bit associated with that data bit is set, the value of the GPIODATA register is altered. If the address bit is cleared, the data bit is left unchanged. For example, writing a value of 0xEB to the address GPIODATA + 0x098 has the results shown in Figure 10-3, where u indicates that data is unchanged by the write. This example demonstrates how GPIODATA bits 5, 2, and 1 are written. Figure 10-3. GPIODATA Write Example ADDR[9:2] 0x098 9 8 7 6 5 4 3 2 1 0 0 0 1 0 0 1 1 0 0 0 0xEB 1 1 1 0 1 0 1 1 GPIODATA u u 1 u u 0 1 u 7 6 5 4 3 2 1 0 During a read, if the address bit associated with the data bit is set, the value is read. If the address bit associated with the data bit is cleared, the data bit is read as a zero, regardless of its actual value. For example, reading address GPIODATA + 0x0C4 yields as shown in Figure 10-4. This example shows how to read GPIODATA bits 5, 4, and 0. Figure 10-4. GPIODATA Read Example ADDR[9:2] 0x0C4 9 8 7 6 5 4 3 2 1 0 0 0 1 1 0 0 0 1 0 0 GPIODATA 1 0 1 1 1 1 1 0 Returned Value 0 0 1 1 0 0 0 0 7 6 5 4 3 2 1 0 June 18, 2014 749 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) 10.3.2 Interrupt Control The interrupt capabilities of each GPIO port are controlled by a set of seven registers. These registers are used to select the source of the interrupt, its polarity, and the edge properties. When one or more GPIO inputs cause an interrupt, a single interrupt output is sent to the interrupt controller for the entire GPIO port. For edge-triggered interrupts, software must clear the interrupt to enable any further interrupts. For a level-sensitive interrupt, the external source must hold the level constant for the interrupt to be recognized by the controller. Three registers define the edge or sense that causes interrupts: ■ GPIO Interrupt Sense (GPIOIS) register (see page 761) ■ GPIO Interrupt Both Edges (GPIOIBE) register (see page 762) ■ GPIO Interrupt Event (GPIOIEV) register (see page 763) Interrupts are enabled/disabled via the GPIO Interrupt Mask (GPIOIM) register (see page 764). When an interrupt condition occurs, the state of the interrupt signal can be viewed in two locations: the GPIO Raw Interrupt Status (GPIORIS) and GPIO Masked Interrupt Status (GPIOMIS) registers (see page 765 and page 767). As the name implies, the GPIOMIS register only shows interrupt conditions that are allowed to be passed to the interrupt controller. The GPIORIS register indicates that a GPIO pin meets the conditions for an interrupt, but has not necessarily been sent to the interrupt controller. For a GPIO level-detect interrupt, the interrupt signal generating the interrupt must be held until serviced. Once the input signal deasserts from the interrupt generating logical sense, the corresponding RIS bit in the GPIORIS register clears. For a GPIO edge-detect interrupt, the RIS bit in the GPIORIS register is cleared by writing a ‘1’ to the corresponding bit in the GPIO Interrupt Clear (GPIOICR) register (see page 769). The corresponding GPIOMIS bit reflects the masked value of the RIS bit. When programming the interrupt control registers (GPIOIS, GPIOIBE, or GPIOIEV), the interrupts should be masked (GPIOIM cleared). Writing any value to an interrupt control register can generate a spurious interrupt if the corresponding bits are enabled. 10.3.2.1 Interrupts Per Pin Each pin of GPIO Port P and Port Q can trigger an interrupt. Each pin has a dedicated interrupt vector and can be handled by a separate interrupt handler. The PP0 and PQ0 interrupts serve as a master interrupt and provide a legacy aggregated interrupt version. For interrupt assignments, see Table 2-9 on page 116. Note: 10.3.2.2 The OR'ed summary interrupt occurs on bit 0 of the GPIORIS register. For summary interrupt mode, software should set the GPIOIM register to 0xFF and mask the port pin interrupts 1 through 7 in the Interrupt Clear Enable (DISn) register (see “NVIC Register Descriptions” on page 153). When servicing this interrupt, write a 1 to the corresponding bit in the UNPENDn register to clear the pending interrupt in the NVIC and clear the GPIORIS register pin interrupt bits by setting the IC field of the GPIOICR register to 0xFF. ADC Trigger Source Any GPIO pin can be configured to be an external trigger for the ADC using the GPIO ADC Control (GPIOADCCTL) register. If any GPIO is configured as a non-masked interrupt pin (the appropriate bit of GPIOIM is set), and an interrupt for that port is generated, a trigger signal is sent to the ADC. If the ADC Event Multiplexer Select (ADCEMUX) register is configured to use the external trigger, 750 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller an ADC conversion is initiated. See page 1091. Note that whether the GPIO is configured to trigger on edge events or level events, a single-clock ADC trigger pulse is created in either event. Thus, when a level event is selected, the ADC sample sequence will run only one time and multiple sample sequences will not be executed if the level remains the same. It is recommended that edge events be used as ADC trigger source. Note that if the Port B GPIOADCCTL register is cleared, PB4 can still be used as an external trigger for the ADC. This is a legacy mode which allows code written for previous devices to operate on this microcontroller. 10.3.2.3 μDMA Trigger Source Any GPIO pin can be configured to be an external trigger for the μDMA using the GPIO DMA Control (GPIODMACTL) register. If any GPIO is configured as a non-masked interrupt pin (the appropriate bit of GPIOIM is set), a dma_req signal is sent to the µDMA. If the μDMA is configured to start a transfer based on the GPIO signal, a transfer is initiated. When transfer is complete, the dma_done signal is sent from the µDMA to the GPIO and is reported as a DMA (done) interrupt in the GPIORIS register. 10.3.2.4 HIB Wake Source GPIO pins K[7:4] on Port K can be configured as an external wake source for the hibernation (HIB) module. The pins can be configured in the following way: 1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation oscillator. 2. Write any data to be retained during power cut to the HIBDATA register at offsets 0x030-0x06F. 3. Configure the GPIOWAKEPEN and GPIOWAKELVL registers at offsets 0x540 and 0x544 in the GPIO module. Enable the I/O wake pad configuration by writing 0x0000.0001 to the HIBIO register at offset 0x010. 4. When the IOWRC bit in the HIBIO register is read as 1, write 0x0000.0000 to the HIBO register to lock the current pad configuration so that any other writes to the GPIOWAKEPEN and GPIOWAKELVL register will be ignored. 5. The hibernation sequence may be initiated by writing 0x0000.0052 to the HIBCTL register. The GPIOWAKESTAT register at offset 0x548 can be read to determine which port caused a wake pin assertion. 10.3.3 Mode Control The GPIO pins can be controlled by either software or hardware. Software control is the default for most signals and corresponds to the GPIO mode, where the GPIODATA register is used to read or write the corresponding pins. When hardware control is enabled via the GPIO Alternate Function Select (GPIOAFSEL) register (see page 770), the pin state is controlled by its alternate function (that is, the peripheral). Further pin muxing options are provided through the GPIO Port Control (GPIOPCTL) register which selects one of several peripheral functions for each GPIO. For information on the configuration options, refer to Table 26-5 on page 1808. Note: If any pin is to be used as an ADC input, the appropriate bit in the GPIOAMSEL register must be set to disable the analog isolation circuit. June 18, 2014 751 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) 10.3.4 Commit Control The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. Protection is provided for the GPIO pins that can be used as the four JTAG/SWD pins and the NMI pin (see “Signal Tables” on page 1772 for pin numbers). Writes to protected bits of the GPIO Alternate Function Select (GPIOAFSEL) register (see page 770), GPIO Pull Up Select (GPIOPUR) register (see page 776), GPIO Pull-Down Select (GPIOPDR) register (see page 778), and GPIO Digital Enable (GPIODEN) register (see page 781) are not committed to storage unless the GPIO Lock (GPIOLOCK) register (see page 783) has been unlocked and the appropriate bits of the GPIO Commit (GPIOCR) register (see page 784) have been set. 10.3.5 Pad Control The pad control registers allow software to configure the GPIO pads based on the application requirements. The pad control registers include the GPIODR2R, GPIODR4R, GPIODR8R,GPIODR12R, GPIOODR, GPIOPUR, GPIOPDR, GPIOSLR, and GPIODEN registers. These registers control drive strength, open-drain configuration, pull-up and pull-down resistors, slew-rate control and digital input enable for each GPIO. If 3.3V is applied to a GPIO configured as an open-drain output, the output voltage will depend on the strength of your pull-up resistor. The GPIO pad is not electrically configured to output 3.3 V. 10.3.5.1 Note: Port pins PL6 and PL7 operate as Fast GPIO pads, but have 4-mA drive capability only. GPIO register controls for drive strength, slew rate and open drain have no effect on these pins. The registers which have no effect are as follows: GPIODR2R, GPIODR4R, GPIODR8R, GPIODR12R, GPIOSLR, and GPIOODR. Note: Port pins PM[7:4] operate as Fast GPIO pads but support only 2-, 4-, 6-, and 8-mA drive capability. 10- and 12-mA drive are not supported. All standard GPIO register controls, except for the GPIODR12R register, apply to these port pins. Extended Drive Enable The GPIO Peripheral Configuration (GPIOPC) register controls the extended drive modes of the GPIO. When the EDE bit in GPIO Peripheral Properties (GPIOPP) register is set and the EDMn bit field for a GPIO pin is non-zero in the GPIOPC register, the GPIODRnR registers do not drive their default value, but instead output an incremental drive strength, which has an additive effect. This allows for more drive strength possibilities. When the EDE bit is set and the EDMn bit field is non-zero, the 2 mA driver is always enabled. Any bits enabled in the GPIODR4R register for a pin with a non-zero EDMn value, add an additional 2 mA. Any bits set in the GPIODR8R add an extra 4 mA of drive. The GPIODR12R register is only valid when the EDMn value is 0x3. For this encoding, setting a bit in the GPIODR12R register adds 4 mA of drive to the already existing 8 mA, for a 12 mA drive strength. To attain a 10-mA drive strength, the pin's GPIODR12R and GPIODR8R register should be enabled; this would result in the addition of two, 4-mA current drivers to the already enabled 2-mA driver. The table below shows the drive capability options. If EDMn is 0x00, then the GPIODR2R, GPIODR4R, and GPIODR8R function as stated in their default register description. Note: A GPIOPC register write must precede the configuration of the GPIODRnR registers in order for extended drive mode to take effect. 752 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 10-3. GPIO Drive Strength Options EDE (GPIOPP) X 1 1 1 10.3.6 EDMn (GPIOPC) 0x0 0x1 0x3 0x2 GPIODR12R (+4mA) N/A N/A GPIODR8R (+4mA) GPIODR4R (+2mA) GPIODR2R (2mA) Drive (mA) 0 0 1 2 0 1 0 4 1 0 0 8 0 0 N/A 2 0 1 N/A 4 1 0 N/A 6 1 1 N/A 8 0 0 0 N/A 2 0 0 1 N/A 4 0 1 0 N/A 6 0 1 1 N/A 8 1 1 0 N/A 10 1 1 1 N/A 12 1 0 N/A N/A N/A N/A N/A N/A N/A N/A Identification The identification registers configured at reset allow software to detect and identify the module as a GPIO block. The identification registers include the GPIOPeriphID0-GPIOPeriphID7 registers as well as the GPIOPCellID0-GPIOPCellID3 registers. 10.4 Initialization and Configuration To configure the GPIO pins of a particular port, follow these steps: 1. Enable the clock to the port by setting the appropriate bits in the RCGCGPIO register (see page 382). In addition, the SCGCGPIO and DCGCGPIO registers can be programmed in the same manner to enable clocking in Sleep and Deep-Sleep modes. 2. Set the direction of the GPIO port pins by programming the GPIODIR register. A write of a 1 indicates output and a write of a 0 indicates input. 3. Configure the GPIOAFSEL register to program each bit as a GPIO or alternate pin. If an alternate pin is chosen for a bit, then the PMCx field must be programmed in the GPIOPCTL register for the specific peripheral required. There are also two registers, GPIOADCCTL and GPIODMACTL, which can be used to program a GPIO pin as a ADC or μDMA trigger, respectively. 4. Set the EDMn field in the GPIOPC register as shown in Table 10-3 on page 753. 5. Set or clear the GPIODR4R register bits as shown in Table 10-3 on page 753. 6. Set or clear the GPIODR8R register bits as shown in Table 10-3 on page 753. 7. Set or clear the GPIODR12R register bits as shown in Table 10-3 on page 753. June 18, 2014 753 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) 8. Program each pad in the port to have either pull-up, pull-down, or open drain functionality through the GPIOPUR, GPIOPDR, GPIOODR register. Slew rate may also be programmed, if needed, through the GPIOSLR register. 9. To enable GPIO pins as digital I/Os, set the appropriate DEN bit in the GPIODEN register. To enable GPIO pins to their analog function (if available), set the GPIOAMSEL bit in the GPIOAMSEL register. 10. Program the GPIOIS, GPIOIBE, GPIOEV, and GPIOIM registers to configure the type, event, and mask of the interrupts for each port. Note: To prevent false interrupts, the following steps should be taken when re-configuring GPIO edge and interrupt sense registers: a. Mask the corresponding port by clearing the IME field in the GPIOIM register. b. Configure the IS field in the GPIOIS register and the IBE field in the GPIOIBE register. c. Clear the GPIORIS register. d. Unmask the port by setting the IME field in the GPIOIM register. 11. Optionally, software can lock the configurations of the NMI and JTAG/SWD pins on the GPIO port pins, by setting the LOCK bits in the GPIOLOCK register. When the internal POR signal is asserted and until otherwise configured, all GPIO pins are configured to be undriven (tristate): GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, and GPIOPUR=0Table 10-4 on page 754 shows all possible configurations of the GPIO pads and the control register settings required to achieve them. Table 10-5 on page 755 shows how a rising edge interrupt is configured for pin 2 of a GPIO port. Table 10-4. GPIO Pad Configuration Examples a Configuration GPIO Register Bit Value ODR DEN PUR PDR Digital Input (GPIO) AFSEL 0 DIR 0 0 1 ? ? DR2R X DR4R X X X X Digital Output (GPIO) 0 1 0 1 ? ? ? ? ? ? ? Open Drain Output (GPIO) 0 1 1 1 X X ? ? ? ? ? Open Drain Input/Output (I2CSDA) 1 X 1 1 X X ? ? ? ? ? Digital Input/Output (I2CSCL) 1 X 0 1 X X ? ? ? ? Digital Input (Timer CCP) 1 X 0 1 ? ? X X X X X Digital Input (QEI) 1 X 0 1 ? ? X X X X X Digital Output (PWM) 1 X 0 1 ? ? ? ? ? ? ? Digital Output (Timer PWM) 1 X 0 1 ? ? ? ? ? ? ? 754 DR8R DR12R SLR ? June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 10-4. GPIO Pad Configuration Examples (continued) a Configuration GPIO Register Bit Value ODR DEN PUR PDR Digital Input/Output (SSI) AFSEL 1 DIR X 0 1 ? ? DR2R ? DR4R ? DR8R ? DR12R ? SLR ? Digital Input/Output (UART) 1 X 0 1 ? ? ? ? ? ? ? Analog Input (Comparator) 0 0 0 0 0 0 X X X X X Digital Output (Comparator) 1 X 0 1 ? ? ? ? ? ? ? a. X=Ignored (don’t care bit) ?=Can be either 0 or 1, depending on the configuration Table 10-5. GPIO Interrupt Configuration Example Desired Interrupt Event Trigger Register GPIOIS 0=edge a Pin 2 Bit Value 7 6 5 4 3 2 1 0 X X X X X 0 X X X X X X X 0 X X X X X X X 1 X X 0 0 0 0 0 1 0 0 1=level GPIOIBE 0=single edge 1=both edges GPIOIEV 0=Low level, or falling edge 1=High level, or rising edge GPIOIM 0=masked 1=not masked a. X=Ignored (don’t care bit) 10.5 Register Map Table 10-7 on page 757 lists the GPIO registers. Important: The GPIO registers in this chapter are duplicated in each GPIO block; however, depending on the block, all eight bits may not be connected to a GPIO pad. In those cases, writing to unconnected bits has no effect, and reading unconnected bits returns no meaningful data. See “Signal Description” on page 743 for the GPIOs included on this device. The offset listed is a hexadecimal increment to the register's address, relative to that GPIO port's base address: ■ ■ ■ ■ ■ ■ ■ ■ GPIO Port A (AHB): 0x4005.8000 GPIO Port B (AHB): 0x4005.9000 GPIO Port C (AHB): 0x4005.A000 GPIO Port D (AHB): 0x4005.B000 GPIO Port E (AHB): 0x4005.C000 GPIO Port F (AHB): 0x4005.D000 GPIO Port G (AHB): 0x4005.E000 GPIO Port H (AHB): 0x4005.F000 June 18, 2014 755 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) ■ ■ ■ ■ ■ ■ ■ GPIO Port J (AHB): 0x4006.0000 GPIO Port K (AHB): 0x4006.1000 GPIO Port L (AHB): 0x4006.2000 GPIO Port M (AHB): 0x4006.3000 GPIO Port N (AHB): 0x4006.4000 GPIO Port P (AHB): 0x4006.5000 GPIO Port Q (AHB): 0x4006.6000 Note that each GPIO module clock must be enabled before the registers can be programmed (see page 382). There must be a delay of 3 system clocks after the GPIO module clock is enabled before any GPIO module registers are accessed. Important: The table below shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 10-6. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 PD[7] GPIO PE[7] GPIO a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware signals including the GPIO pins that can function as JTAG/SWD signals and the NMI signal. The commit control process must be followed for these pins, even if they are programmed as alternate functions other than JTAG/SWD or NMI; see “Commit Control” on page 752. Note: If the device fails initialization during reset, the hardware toggles the TDO output as an indication of failure. Thus, during board layout, designers should not designate the TDO pin as a GPIO in sensitive applications where the possibility of toggling could affect the design. The default register type for the GPIOCR register is RO for all GPIO pins with the exception of the NMI pin and the four JTAG/SWD pins (see “Signal Tables” on page 1772 for pin numbers). These six pins are the only GPIOs that are protected by the GPIOCR register. Because of this, the register type for the corresponding GPIO Ports is RW. The default reset value for the GPIOCR register is 0x0000.00FF for all GPIO pins, with the exception of the NMI and JTAG/SWD pins (see “Signal Tables” on page 1772 for pin numbers). To ensure that the JTAG and NMI pins are not accidentally programmed as GPIO pins, these pins default to non-committable. Because of this, the default reset value of GPIOCR changes for the corresponding ports. 756 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 10-7. GPIO Register Map Offset Name 0x000 Description See page Type Reset GPIODATA RW 0x0000.0000 GPIO Data 759 0x400 GPIODIR RW 0x0000.0000 GPIO Direction 760 0x404 GPIOIS RW 0x0000.0000 GPIO Interrupt Sense 761 0x408 GPIOIBE RW 0x0000.0000 GPIO Interrupt Both Edges 762 0x40C GPIOIEV RW 0x0000.0000 GPIO Interrupt Event 763 0x410 GPIOIM RW 0x0000.0000 GPIO Interrupt Mask 764 0x414 GPIORIS RO 0x0000.0000 GPIO Raw Interrupt Status 765 0x418 GPIOMIS RO 0x0000.0000 GPIO Masked Interrupt Status 767 0x41C GPIOICR W1C 0x0000.0000 GPIO Interrupt Clear 769 0x420 GPIOAFSEL RW - GPIO Alternate Function Select 770 0x500 GPIODR2R RW 0x0000.00FF GPIO 2-mA Drive Select 772 0x504 GPIODR4R RW 0x0000.0000 GPIO 4-mA Drive Select 773 0x508 GPIODR8R RW 0x0000.0000 GPIO 8-mA Drive Select 774 0x50C GPIOODR RW 0x0000.0000 GPIO Open Drain Select 775 0x510 GPIOPUR RW - GPIO Pull-Up Select 776 0x514 GPIOPDR RW 0x0000.0000 GPIO Pull-Down Select 778 0x518 GPIOSLR RW 0x0000.0000 GPIO Slew Rate Control Select 780 0x51C GPIODEN RW - GPIO Digital Enable 781 0x520 GPIOLOCK RW 0x0000.0001 GPIO Lock 783 0x524 GPIOCR - - GPIO Commit 784 0x528 GPIOAMSEL RW 0x0000.0000 GPIO Analog Mode Select 786 0x52C GPIOPCTL RW - GPIO Port Control 787 0x530 GPIOADCCTL RW 0x0000.0000 GPIO ADC Control 789 0x534 GPIODMACTL RW 0x0000.0000 GPIO DMA Control 790 0x538 GPIOSI RW 0x0000.0000 GPIO Select Interrupt 791 0x53C GPIODR12R RW 0x0000.0000 GPIO 12-mA Drive Select 792 0x540 GPIOWAKEPEN RW 0x0000.0000 GPIO Wake Pin Enable 793 0x544 GPIOWAKELVL RW 0x0000.0000 GPIO Wake Level 795 0x548 GPIOWAKESTAT RO 0x0000.0000 GPIO Wake Status 797 0xFC0 GPIOPP RO 0x0000.0001 GPIO Peripheral Property 799 0xFC4 GPIOPC RW 0x0000.0000 GPIO Peripheral Configuration 800 0xFD0 GPIOPeriphID4 RO 0x0000.0000 GPIO Peripheral Identification 4 803 June 18, 2014 757 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Table 10-7. GPIO Register Map (continued) Offset Name 0xFD4 Reset GPIOPeriphID5 RO 0x0000.0000 GPIO Peripheral Identification 5 804 0xFD8 GPIOPeriphID6 RO 0x0000.0000 GPIO Peripheral Identification 6 805 0xFDC GPIOPeriphID7 RO 0x0000.0000 GPIO Peripheral Identification 7 806 0xFE0 GPIOPeriphID0 RO 0x0000.0061 GPIO Peripheral Identification 0 807 0xFE4 GPIOPeriphID1 RO 0x0000.0000 GPIO Peripheral Identification 1 808 0xFE8 GPIOPeriphID2 RO 0x0000.0018 GPIO Peripheral Identification 2 809 0xFEC GPIOPeriphID3 RO 0x0000.0001 GPIO Peripheral Identification 3 810 0xFF0 GPIOPCellID0 RO 0x0000.000D GPIO PrimeCell Identification 0 811 0xFF4 GPIOPCellID1 RO 0x0000.00F0 GPIO PrimeCell Identification 1 812 0xFF8 GPIOPCellID2 RO 0x0000.0005 GPIO PrimeCell Identification 2 813 0xFFC GPIOPCellID3 RO 0x0000.00B1 GPIO PrimeCell Identification 3 814 10.6 Description See page Type Register Descriptions The remainder of this section lists and describes the GPIO registers, in numerical order by address offset. 758 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: GPIO Data (GPIODATA), offset 0x000 The GPIODATA register is the data register. In software control mode, values written in the GPIODATA register are transferred onto the GPIO port pins if the respective pins have been configured as outputs through the GPIO Direction (GPIODIR) register (see page 760). In order to write to GPIODATA, the corresponding bits in the mask, resulting from the address bus bits [9:2], must be set. Otherwise, the bit values remain unchanged by the write. Similarly, the values read from this register are determined for each bit by the mask bit derived from the address used to access the data register, bits [9:2]. Bits that are set in the address mask cause the corresponding bits in GPIODATA to be read, and bits that are clear in the address mask cause the corresponding bits in GPIODATA to be read as 0, regardless of their value. A read from GPIODATA returns the last bit value written if the respective pins are configured as outputs, or it returns the value on the corresponding input pin when these are configured as inputs. All bits are cleared by a reset. GPIO Data (GPIODATA) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 DATA RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DATA RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Data This register is virtually mapped to 256 locations in the address space. To facilitate the reading and writing of data to these registers by independent drivers, the data read from and written to the registers are masked by the eight address lines [9:2]. Reads from this register return its current state. Writes to this register only affect bits that are not masked by ADDR[9:2] and are configured as outputs. See “Data Register Operation” on page 749 for examples of reads and writes. June 18, 2014 759 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 2: GPIO Direction (GPIODIR), offset 0x400 The GPIODIR register is the data direction register. Setting a bit in the GPIODIR register configures the corresponding pin to be an output, while clearing a bit configures the corresponding pin to be an input. All bits are cleared by a reset, meaning all GPIO pins are inputs by default. GPIO Direction (GPIODIR) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x400 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset DIR RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DIR RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Data Direction Value Description 0 Corresponding pin is an input. 1 Corresponding pins is an output. 760 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: GPIO Interrupt Sense (GPIOIS), offset 0x404 The GPIOIS register is the interrupt sense register. Setting a bit in the GPIOIS register configures the corresponding pin to detect levels, while clearing a bit configures the corresponding pin to detect edges. All bits are cleared by a reset. Note: To prevent false interrupts, the following steps should be taken when re-configuring GPIO edge and interrupt sense registers: 1. Mask the corresponding port by clearing the IME field in the GPIOIM register. 2. Configure the IS field in the GPIOIS register and the IBE field in the GPIOIBE register. 3. Clear the GPIORIS register. 4. Unmask the port by setting the IME field in the GPIOIM register. GPIO Interrupt Sense (GPIOIS) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x404 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset IS RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 IS RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Interrupt Sense Value Description 0 The edge on the corresponding pin is detected (edge-sensitive). 1 The level on the corresponding pin is detected (level-sensitive). June 18, 2014 761 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 4: GPIO Interrupt Both Edges (GPIOIBE), offset 0x408 The GPIOIBE register allows both edges to cause interrupts. When the corresponding bit in the GPIO Interrupt Sense (GPIOIS) register (see page 761) is set to detect edges, setting a bit in the GPIOIBE register configures the corresponding pin to detect both rising and falling edges, regardless of the corresponding bit in the GPIO Interrupt Event (GPIOIEV) register (see page 763). Clearing a bit configures the pin to be controlled by the GPIOIEV register. All bits are cleared by a reset. Note: To prevent false interrupts, the following steps should be taken when re-configuring GPIO edge and interrupt sense registers: 1. Mask the corresponding port by clearing the IME field in the GPIOIM register. 2. Configure the IS field in the GPIOIS register and the IBE field in the GPIOIBE register. 3. Clear the GPIORIS register. 4. Unmask the port by setting the IME field in the GPIOIM register. GPIO Interrupt Both Edges (GPIOIBE) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x408 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset IBE RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 IBE RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Interrupt Both Edges Value Description 0 Interrupt generation is controlled by the GPIO Interrupt Event (GPIOIEV) register (see page 763). 1 Both edges on the corresponding pin trigger an interrupt. 762 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: GPIO Interrupt Event (GPIOIEV), offset 0x40C The GPIOIEV register is the interrupt event register. Setting a bit in the GPIOIEV register configures the corresponding pin to detect rising edges or high levels, depending on the corresponding bit value in the GPIO Interrupt Sense (GPIOIS) register (see page 761). Clearing a bit configures the pin to detect falling edges or low levels, depending on the corresponding bit value in the GPIOIS register. All bits are cleared by a reset. GPIO Interrupt Event (GPIOIEV) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x40C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset IEV RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 IEV RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Interrupt Event Value Description 0 A falling edge or a Low level on the corresponding pin triggers an interrupt. 1 A rising edge or a High level on the corresponding pin triggers an interrupt. June 18, 2014 763 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 6: GPIO Interrupt Mask (GPIOIM), offset 0x410 The GPIOIM register is the interrupt mask register. Setting a bit in the GPIOIM register allows interrupts that are generated by the corresponding pin to be sent to the interrupt controller on the combined interrupt signal. Clearing a bit prevents an interrupt on the corresponding pin from being sent to the interrupt controller. All bits are cleared by a reset. GPIO Interrupt Mask (GPIOIM) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x410 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 DMAIME RW 0 IME Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 DMAIME RW 0 GPIO uDMA Done Interrupt Mask Enable Value Description 7:0 IME RW 0x00 0 The µDMA done interrupt is masked and does not cause an interrupt. 1 The µDMA done interrupt is not masked and can generate an interrupt to the interrupt controller. GPIO Interrupt Mask Enable Value Description 0 The interrupt from the corresponding pin is masked. 1 The interrupt from the corresponding pin is sent to the interrupt controller. 764 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 7: GPIO Raw Interrupt Status (GPIORIS), offset 0x414 The GPIORIS register is the raw interrupt status register. A bit in this register is set when an interrupt condition occurs on the corresponding GPIO pin or if a µDMA done interrupt occurs. If the corresponding bit in the GPIO Interrupt Mask (GPIOIM) register (see page 764) is set, the interrupt is sent to the interrupt controller. Bits read as zero indicate that corresponding input pins have not initiated an interrupt. For a GPIO level-detect interrupt, the interrupt signal generating the interrupt must be held until serviced. Once the input signal deasserts from the interrupt generating logical sense, the corresponding RIS bit in the GPIORIS register clears. For a GPIO edge-detect interrupt, the RIS bit in the GPIORIS register is cleared by writing a ‘1’ to the corresponding bit in the GPIO Interrupt Clear (GPIOICR) register. The corresponding GPIOMIS bit reflects the masked value of the RIS bit. GPIO Raw Interrupt Status (GPIORIS) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x414 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 DMARIS RO 0 RIS Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 DMARIS RO 0 GPIO µDMA Done Interrupt Raw Status Value Description 0 A µDMA done interrupt has not occurred. 1 A µDMA done interrupt has occurred and an interrupt has been triggered and is pending. This bit is cleared by writing a 1 to the DMAIC bit in the GPIOICR register. June 18, 2014 765 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Bit/Field Name Type Reset Description 7:0 RIS RO 0x00 GPIO Interrupt Raw Status Value Description 0 An interrupt condition has not occurred on the corresponding pin. 1 An interrupt condition has occurred on the corresponding pin. For edge-detect interrupts, this bit is cleared by writing a 1 to the corresponding bit in the GPIOICR register. For a GPIO level-detect interrupt, the bit is cleared when the level is deasserted. 766 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: GPIO Masked Interrupt Status (GPIOMIS), offset 0x418 The GPIOMIS register is the masked interrupt status register. If a bit is set in this register, the corresponding interrupt has triggered an interrupt to the interrupt controller. If a bit is clear, either no interrupt has been generated, or the interrupt is masked. Note that if the Port B GPIOADCCTL register is cleared, PB4 can still be used as an external trigger for the ADC. This is a legacy mode which allows code written for previous devices to operate on this microcontroller. GPIOMIS is the state of the interrupt after masking. GPIO Masked Interrupt Status (GPIOMIS) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x418 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 DMAMIS RO 0 MIS Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 DMAMIS RO 0 GPIO µDMA Done Masked Interrupt Status Value Description 0 The µDMA done interrupt is masked or has not occurred. 1 An unmasked µDMA done interrupt has occurred. This bit is cleared by writing a 1 to the DMAIC bit in the GPIOICR register. June 18, 2014 767 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Bit/Field Name Type Reset Description 7:0 MIS RO 0x00 GPIO Masked Interrupt Status Value Description 0 An interrupt condition on the corresponding pin is masked or has not occurred. 1 An interrupt condition on the corresponding pin has triggered an interrupt to the interrupt controller. For edge-detect interrupts, this bit is cleared by writing a 1 to the corresponding bit in the GPIOICR register. For a GPIO level-detect interrupt, the bit is cleared when the level is deasserted. 768 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 9: GPIO Interrupt Clear (GPIOICR), offset 0x41C The GPIOICR register is the interrupt clear register. Writing a 1 to the DMAIC bit in this register clears the corresponding interrupt bit in the GPIORIS and GPIOMIS registers. For edge-detect interrupts, writing a 1 to the IC bit in the GPIOICR register clears the corresponding bit in the GPIORIS and GPIOMIS registers. If the interrupt is a level-detect, the IC bit in this register has no effect. In addition, writing a 0 to any of the bits in the GPIOICR register has no effect. GPIO Interrupt Clear (GPIOICR) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x41C Type W1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 reserved Type Reset reserved Type Reset RO 0 DMAIC W1C 0 IC Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 DMAIC W1C 0 GPIO µDMA Interrupt Clear Value Description 7:0 IC W1C 0x00 0 The µDMA done interrupt is unaffected. 1 The µDMA done interrupt is cleared. GPIO Interrupt Clear Value Description 0 The corresponding interrupt is unaffected. 1 The corresponding interrupt is cleared. June 18, 2014 769 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 10: GPIO Alternate Function Select (GPIOAFSEL), offset 0x420 Note: Tamper pins enabled in the Hibernate Tamper IO Control and Status (HIBTPIO) register override the AFSEL configuration. The GPIOAFSEL register is the mode control select register. If a bit is clear, the pin is used as a GPIO and is controlled by the GPIO registers. Setting a bit in this register configures the corresponding GPIO line to be controlled by an associated peripheral. Several possible peripheral functions are multiplexed on each GPIO. The GPIO Port Control (GPIOPCTL) register is used to select one of the possible functions. Table 26-5 on page 1808 details which functions are muxed on each GPIO pin. The reset value for this register is 0x0000.0000 for GPIO ports that are not listed in the table below. Important: The table below shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 10-8. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 PD[7] GPIO PE[7] GPIO a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware signals including the GPIO pins that can function as JTAG/SWD signals and the NMI signal. The commit control process must be followed for these pins, even if they are programmed as alternate functions other than JTAG/SWD or NMI; see “Commit Control” on page 752. Note: If the device fails initialization during reset, the hardware toggles the TDO output as an indication of failure. Thus, during board layout, designers should not designate the TDO pin as a GPIO in sensitive applications where the possibility of toggling could affect the design. Caution – It is possible to create a software sequence that prevents the debugger from connecting to the TM4C1294NCPDT microcontroller. If the program code loaded into flash immediately changes the JTAG pins to their GPIO functionality, the debugger may not have enough time to connect and halt the controller before the JTAG pin functionality switches. As a result, the debugger may be locked out of the part. This issue can be avoided with a software routine that restores JTAG functionality based on an external or software trigger. In the case that the software routine is not implemented and the device is locked out of the part, this issue can be solved by using the TM4C1294NCPDT Flash Programmer "Unlock" feature. Please refer to LMFLASHPROGRAMMER on the TI web for more information. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. Protection is provided for the GPIO pins that can be used as the four JTAG/SWD pins and the NMI pin (see “Signal Tables” on page 1772 for pin numbers). Writes to protected bits of the GPIO Alternate Function Select (GPIOAFSEL) register (see page 770), GPIO 770 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Pull Up Select (GPIOPUR) register (see page 776), GPIO Pull-Down Select (GPIOPDR) register (see page 778), and GPIO Digital Enable (GPIODEN) register (see page 781) are not committed to storage unless the GPIO Lock (GPIOLOCK) register (see page 783) has been unlocked and the appropriate bits of the GPIO Commit (GPIOCR) register (see page 784) have been set. When using the I2C module, in addition to setting the GPIOAFSEL register bits for the I2C clock and data pins, the data pins should be set to open drain using the GPIO Open Drain Select (GPIOODR) register (see examples in “Initialization and Configuration” on page 753). GPIO Alternate Function Select (GPIOAFSEL) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x420 Type RW, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW - RW - RW - RW - reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 AFSEL RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 AFSEL RW - RO 0 RW - RW - RW - RW - Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Alternate Function Select Value Description 0 The associated pin functions as a GPIO and is controlled by the GPIO registers. 1 The associated pin functions as a peripheral signal and is controlled by the alternate hardware function. The reset value for this register is 0x0000.0000 for GPIO ports that are not listed in Table 10-1 on page 743. June 18, 2014 771 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 11: GPIO 2-mA Drive Select (GPIODR2R), offset 0x500 The GPIODR2R register is the 2-mA drive control register. Each GPIO signal in the port can be individually configured without affecting the other pads. When setting the DRV2 bit for a GPIO signal, the corresponding DRV4 bit in the GPIODR4R register and DRV8 bit in the GPIODR8R register are automatically cleared by hardware. By default, all GPIO pins have 2-mA drive. Note: This register has no effect on port pins PL6 and PL7. GPIO 2-mA Drive Select (GPIODR2R) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x500 Type RW, reset 0x0000.00FF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 1 RW 1 RW 1 RW 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 DRV2 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DRV2 RW 0xFF RO 0 RW 1 RW 1 RW 1 RW 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Output Pad 2-mA Drive Enable Value Description 0 The drive for the corresponding GPIO pin is controlled by the GPIODR4R or GPIODR8R register. 1 The corresponding GPIO pin has 2-mA drive. Setting a bit in either the GPIODR4 register or the GPIODR8 register clears the corresponding 2-mA enable bit. The change is effective on the next clock cycle. 772 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 12: GPIO 4-mA Drive Select (GPIODR4R), offset 0x504 The GPIODR4R register is the 4-mA drive control register. Each GPIO signal in the port can be individually configured without affecting the other pads. When setting the DRV4 bit for a GPIO signal, the corresponding DRV2 bit in the GPIODR2R register and DRV8 bit in the GPIODR8R register are automatically cleared by hardware. Note: This register has no effect on port pins PL6 and PL7. GPIO 4-mA Drive Select (GPIODR4R) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x504 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 DRV4 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DRV4 RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Output Pad 4-mA Drive Enable Value Description 0 The drive for the corresponding GPIO pin is controlled by the GPIODR2R or GPIODR8R register. 1 The corresponding GPIO pin has 4-mA drive. Setting a bit in either the GPIODR2 register or the GPIODR8 register clears the corresponding 4-mA enable bit. The change is effective on the next clock cycle. June 18, 2014 773 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 13: GPIO 8-mA Drive Select (GPIODR8R), offset 0x508 The GPIODR8R register is the 8-mA drive control register. Each GPIO signal in the port can be individually configured without affecting the other pads. When setting the DRV8 bit for a GPIO signal, the corresponding DRV2 bit in the GPIODR2R register and DRV4 bit in the GPIODR4R register are automatically cleared by hardware. The 8-mA setting is also used for high-current operation. Note: There is no configuration difference between 8-mA and high-current operation. The additional current capacity results from a shift in the VOH/VOL levels. See “Recommended Operating Conditions” on page 1820 for further information. Note: This register has no effect on port pins PL6 and PL7. GPIO 8-mA Drive Select (GPIODR8R) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x508 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset DRV8 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DRV8 RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Output Pad 8-mA Drive Enable Value Description 0 The drive for the corresponding GPIO pin is controlled by the GPIODR2R or GPIODR4R register. 1 The corresponding GPIO pin has 8-mA drive. Setting a bit in either the GPIODR2 register or the GPIODR4 register clears the corresponding 8-mA enable bit. The change is effective on the next clock cycle. 774 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 14: GPIO Open Drain Select (GPIOODR), offset 0x50C The GPIOODR register is the open drain control register. Setting a bit in this register enables the open-drain configuration of the corresponding GPIO pad. When open-drain mode is enabled, the corresponding bit should also be set in the GPIO Digital Enable (GPIODEN) register (see page 781). Corresponding bits in the drive strength and slew rate control registers (GPIODR2R, GPIODR4R, GPIODR8R, and GPIOSLR) can be set to achieve the desired fall times. The GPIO acts as an input if the corresponding bit in the GPIODIR register is cleared. If open drain is selected while the GPIO is configured as an input, the GPIO will remain an input and the open-drain selection has no effect until the GPIO is changed to an output. When using the I2C module, in addition to configuring the data pin to open drain, the GPIO Alternate Function Select (GPIOAFSEL) register bits for the I2C clock and data pins should be set (see examples in “Initialization and Configuration” on page 753). Note: This register has no effect on port pins PL6 and PL7. GPIO Open Drain Select (GPIOODR) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x50C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset ODE RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 ODE RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Output Pad Open Drain Enable Value Description 0 The corresponding pin is not configured as open drain. 1 The corresponding pin is configured as open drain. June 18, 2014 775 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 15: GPIO Pull-Up Select (GPIOPUR), offset 0x510 The GPIOPUR register is the pull-up control register. When a bit is set, a weak pull-up resistor on the corresponding GPIO signal is enabled. Setting a bit in GPIOPUR automatically clears the corresponding bit in the GPIO Pull-Down Select (GPIOPDR) register (see page 778). Write access to this register is protected with the GPIOCR register. Bits in GPIOCR that are cleared prevent writes to the equivalent bit in this register. Important: The table below shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 10-9. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD PD[7] GPIO PE[7] GPIO GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware signals including the GPIO pins that can function as JTAG/SWD signals and the NMI signal. The commit control process must be followed for these pins, even if they are programmed as alternate functions other than JTAG/SWD or NMI; see “Commit Control” on page 752. Note: Note: If the device fails initialization during reset, the hardware toggles the TDO output as an indication of failure. Thus, during board layout, designers should not designate the TDO pin as a GPIO in sensitive applications where the possibility of toggling could affect the design. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. Protection is provided for the GPIO pins that can be used as the four JTAG/SWD pins and the NMI pin (see “Signal Tables” on page 1772 for pin numbers). Writes to protected bits of the GPIO Alternate Function Select (GPIOAFSEL) register (see page 770), GPIO Pull Up Select (GPIOPUR) register (see page 776), GPIO Pull-Down Select (GPIOPDR) register (see page 778), and GPIO Digital Enable (GPIODEN) register (see page 781) are not committed to storage unless the GPIO Lock (GPIOLOCK) register (see page 783) has been unlocked and the appropriate bits of the GPIO Commit (GPIOCR) register (see page 784) have been set. 776 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller GPIO Pull-Up Select (GPIOPUR) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x510 Type RW, reset 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW - RW - RW - RW - RW - RW - RW - RW - reserved Type Reset reserved Type Reset PUE RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PUE RW - Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Pad Weak Pull-Up Enable Value Description 0 The corresponding pin's weak pull-up resistor is disabled. 1 The corresponding pin's weak pull-up resistor is enabled. Setting a bit in the GPIOPDR register clears the corresponding bit in the GPIOPUR register. The change is effective on the next clock cycle. The reset value for this register is 0x0000.0000 for GPIO ports that are not listed in Table 10-1 on page 743. June 18, 2014 777 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 16: GPIO Pull-Down Select (GPIOPDR), offset 0x514 The GPIOPDR register is the pull-down control register. When a bit is set, a weak pull-down resistor on the corresponding GPIO signal is enabled. Setting a bit in GPIOPDR automatically clears the corresponding bit in the GPIO Pull-Up Select (GPIOPUR) register (see page 776). Important: The table below shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 10-10. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD PD[7] GPIO PE[7] GPIO GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware signals including the GPIO pins that can function as JTAG/SWD signals and the NMI signal. The commit control process must be followed for these pins, even if they are programmed as alternate functions other than JTAG/SWD or NMI; see “Commit Control” on page 752. Note: Note: If the device fails initialization during reset, the hardware toggles the TDO output as an indication of failure. Thus, during board layout, designers should not designate the TDO pin as a GPIO in sensitive applications where the possibility of toggling could affect the design. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. Protection is provided for the GPIO pins that can be used as the four JTAG/SWD pins and the NMI pin (see “Signal Tables” on page 1772 for pin numbers). Writes to protected bits of the GPIO Alternate Function Select (GPIOAFSEL) register (see page 770), GPIO Pull Up Select (GPIOPUR) register (see page 776), GPIO Pull-Down Select (GPIOPDR) register (see page 778), and GPIO Digital Enable (GPIODEN) register (see page 781) are not committed to storage unless the GPIO Lock (GPIOLOCK) register (see page 783) has been unlocked and the appropriate bits of the GPIO Commit (GPIOCR) register (see page 784) have been set. 778 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller GPIO Pull-Down Select (GPIOPDR) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x514 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset PDE RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PDE RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Pad Weak Pull-Down Enable Value Description 0 The corresponding pin's weak pull-down resistor is disabled. 1 The corresponding pin's weak pull-down resistor is enabled. Setting a bit in the GPIOPUR register clears the corresponding bit in the GPIOPDR register. The change is effective on the next clock cycle. June 18, 2014 779 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 17: GPIO Slew Rate Control Select (GPIOSLR), offset 0x518 The GPIOSLR register is the slew rate control register. Slew rate control is only available when using the 8-mA, 10-mA or 12-mA drive strength option. The selection of drive strength is done through the GPIO Drive Select (GPIODRnR registers and the GPIO Peripheral Configuration (GPIOPC) register. Note: This register has no effect on port pins PL6 and PL7. GPIO Slew Rate Control Select (GPIOSLR) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x518 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 SRL RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 SRL RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Slew Rate Limit Enable (8-mA, 10-mA and 12-mA drive only) Value Description 0 Slew rate control is disabled for the corresponding pin. 1 Slew rate control is enabled for the corresponding pin. 780 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 18: GPIO Digital Enable (GPIODEN), offset 0x51C Note: Pins configured as digital inputs are Schmitt-triggered. The GPIODEN register is the digital enable register. By default, all GPIO signals except those listed below are configured out of reset to be undriven (tristate). Their digital function is disabled; they do not drive a logic value on the pin and they do not allow the pin voltage into the GPIO receiver. To use the pin as a digital input or output (either GPIO or alternate function), the corresponding GPIODEN bit must be set. Important: The table below shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 10-11. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 PD[7] GPIO PE[7] GPIO a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware signals including the GPIO pins that can function as JTAG/SWD signals and the NMI signal. The commit control process must be followed for these pins, even if they are programmed as alternate functions other than JTAG/SWD or NMI; see “Commit Control” on page 752. Note: Note: If the device fails initialization during reset, the hardware toggles the TDO output as an indication of failure. Thus, during board layout, designers should not designate the TDO pin as a GPIO in sensitive applications where the possibility of toggling could affect the design. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. Protection is provided for the GPIO pins that can be used as the four JTAG/SWD pins and the NMI pin (see “Signal Tables” on page 1772 for pin numbers). Writes to protected bits of the GPIO Alternate Function Select (GPIOAFSEL) register (see page 770), GPIO Pull Up Select (GPIOPUR) register (see page 776), GPIO Pull-Down Select (GPIOPDR) register (see page 778), and GPIO Digital Enable (GPIODEN) register (see page 781) are not committed to storage unless the GPIO Lock (GPIOLOCK) register (see page 783) has been unlocked and the appropriate bits of the GPIO Commit (GPIOCR) register (see page 784) have been set. June 18, 2014 781 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) GPIO Digital Enable (GPIODEN) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x51C Type RW, reset 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW - RW - RW - RW - RW - RW - RW - RW - reserved Type Reset reserved Type Reset DEN RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DEN RW - Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Digital Enable Value Description 0 The digital functions for the corresponding pin are disabled. 1 The digital functions for the corresponding pin are enabled. The reset value for this register is 0x0000.0000 for GPIO ports that are not listed in Table 10-1 on page 743. 782 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: GPIO Lock (GPIOLOCK), offset 0x520 The GPIOLOCK register enables write access to the GPIOCR register (see page 784). Writing 0x4C4F.434B to the GPIOLOCK register unlocks the GPIOCR register. Writing any other value to the GPIOLOCK register re-enables the locked state. Reading the GPIOLOCK register returns the lock status rather than the 32-bit value that was previously written. Therefore, when write accesses are disabled, or locked, reading the GPIOLOCK register returns 0x0000.0001. When write accesses are enabled, or unlocked, reading the GPIOLOCK register returns 0x0000.0000. GPIO Lock (GPIOLOCK) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x520 Type RW, reset 0x0000.0001 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 1 LOCK Type Reset LOCK Type Reset Bit/Field Name Type 31:0 LOCK RW Reset Description 0x0000.0001 GPIO Lock A write of the value 0x4C4F.434B unlocks the GPIO Commit (GPIOCR) register for write access.A write of any other value or a write to the GPIOCR register reapplies the lock, preventing any register updates. A read of this register returns the following values: Value Description 0x1 The GPIOCR register is locked and may not be modified. 0x0 The GPIOCR register is unlocked and may be modified. June 18, 2014 783 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 20: GPIO Commit (GPIOCR), offset 0x524 The GPIOCR register is the commit register. The value of the GPIOCR register determines which bits of the GPIOAFSEL, GPIOPUR, GPIOPDR, and GPIODEN registers are committed when a write to these registers is performed. If a bit in the GPIOCR register is cleared, the data being written to the corresponding bit in the GPIOAFSEL, GPIOPUR, GPIOPDR, or GPIODEN registers cannot be committed and retains its previous value. If a bit in the GPIOCR register is set, the data being written to the corresponding bit of the GPIOAFSEL, GPIOPUR, GPIOPDR, or GPIODEN registers is committed to the register and reflects the new value. The contents of the GPIOCR register can only be modified if the status in the GPIOLOCK register is unlocked. Writes to the GPIOCR register are ignored if the status in the GPIOLOCK register is locked. Important: This register is designed to prevent accidental programming of the registers that control connectivity to the NMI and JTAG/SWD debug hardware. By initializing the bits of the GPIOCR register to 0 for the NMI and JTAG/SWD pins (see “Signal Tables” on page 1772 for pin numbers), the NMI and JTAG/SWD debug port can only be converted to GPIOs through a deliberate set of writes to the GPIOLOCK, GPIOCR, and the corresponding registers. Because this protection is currently only implemented on the NMI and JTAG/SWD pins (see “Signal Tables” on page 1772 for pin numbers), all of the other bits in the GPIOCR registers cannot be written with 0x0. These bits are hardwired to 0x1, ensuring that it is always possible to commit new values to the GPIOAFSEL, GPIOPUR, GPIOPDR, or GPIODEN register bits of these other pins. GPIO Commit (GPIOCR) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x524 Type -, reset 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 - - - - - - - - reserved Type Reset reserved Type Reset CR RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 784 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 7:0 CR - - Description GPIO Commit Value Description 0 The corresponding GPIOAFSEL, GPIOPUR, GPIOPDR, or GPIODEN bits cannot be written. 1 The corresponding GPIOAFSEL, GPIOPUR, GPIOPDR, or GPIODEN bits can be written. Note: The default register type for the GPIOCR register is RO for all GPIO pins with the exception of the NMI pin and the four JTAG/SWD pins (see “Signal Tables” on page 1772 for pin numbers). These six pins are the only GPIOs that are protected by the GPIOCR register. Because of this, the register type for the corresponding GPIO Ports is RW. The default reset value for the GPIOCR register is 0x0000.00FF for all GPIO pins, with the exception of the NMI and JTAG/SWD pins (see “Signal Tables” on page 1772 for pin numbers). To ensure that the JTAG and NMI pins are not accidentally programmed as GPIO pins, these pins default to non-committable. Because of this, the default reset value of GPIOCR changes for the corresponding ports. June 18, 2014 785 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 21: GPIO Analog Mode Select (GPIOAMSEL), offset 0x528 Important: This register is only valid for ports and pins that can be used as ADC AINx inputs. If any pin is to be used as an ADC input, the appropriate bit in GPIOAMSEL must be set to disable the analog isolation circuit. The GPIOAMSEL register controls isolation circuits to the analog side of a unified I/O pad. Because the GPIOs may be driven by a 3.3-V source and affect analog operation, analog circuitry requires isolation from the pins when they are not used in their analog function. Each bit of this register controls the isolation circuitry for the corresponding GPIO signal. For information on which GPIO pins can be used for ADC functions, refer to Table 26-5 on page 1808. GPIO Analog Mode Select (GPIOAMSEL) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x528 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset GPIOAMSEL RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 GPIOAMSEL RW 0x00 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Analog Mode Select Value Description 0 The analog function of the pin is disabled, the isolation is enabled, and the pin is capable of digital functions as specified by the other GPIO configuration registers. 1 The analog function of the pin is enabled, the isolation is disabled, and the pin is capable of analog functions. Note: This register and bits are only valid for GPIO signals that share analog function through a unified I/O pad. The reset state of this register is 0 for all signals. 786 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 22: GPIO Port Control (GPIOPCTL), offset 0x52C The GPIOPCTL register is used in conjunction with the GPIOAFSEL register and selects the specific peripheral signal for each GPIO pin when using the alternate function mode. Most bits in the GPIOAFSEL register are cleared on reset, therefore most GPIO pins are configured as GPIOs by default. When a bit is set in the GPIOAFSEL register, the corresponding GPIO signal is controlled by an associated peripheral. The GPIOPCTL register selects one out of a set of peripheral functions for each GPIO, providing additional flexibility in signal definition. For information on the defined encodings for the bit fields in this register, refer to Table 26-5 on page 1808. The reset value for this register is 0x0000.0000 for GPIO ports that are not listed in the table below. Note: If a particular input signal to a peripheral is assigned to two different GPIO port pins, the signal is assigned to the port with the lowest letter and the assignment to the higher letter port is ignored. If a particular output signal from a peripheral is assigned to two different GPIO port pins, the signal will output to both pins. Assigning an output signal from a peripheral to two different GPIO pins is not recommended. Important: The table below shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 10-12. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 PD[7] GPIO PE[7] GPIO a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware signals including the GPIO pins that can function as JTAG/SWD signals and the NMI signal. The commit control process must be followed for these pins, even if they are programmed as alternate functions other than JTAG/SWD or NMI; see “Commit Control” on page 752. Note: If the device fails initialization during reset, the hardware toggles the TDO output as an indication of failure. Thus, during board layout, designers should not designate the TDO pin as a GPIO in sensitive applications where the possibility of toggling could affect the design. June 18, 2014 787 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) GPIO Port Control (GPIOPCTL) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x52C Type RW, reset 31 30 29 28 27 26 RW - 25 24 23 22 RW - RW - RW - RW - RW - RW - RW - RW - 15 14 13 12 11 10 9 8 RW - RW - RW - RW - RW - RW - RW - RW - PMC7 Type Reset 20 19 18 RW - RW - RW - RW - 7 6 5 4 RW - RW - RW - RW - PMC6 PMC3 Type Reset 21 17 16 RW - RW - RW - 3 2 1 0 RW - RW - RW - RW - PMC5 PMC2 PMC4 PMC1 Bit/Field Name Type Reset 31:28 PMC7 RW - PMC0 Description Port Mux Control 7 This field controls the configuration for GPIO pin 7. 27:24 PMC6 RW - Port Mux Control 6 This field controls the configuration for GPIO pin 6. 23:20 PMC5 RW - Port Mux Control 5 This field controls the configuration for GPIO pin 5. 19:16 PMC4 RW - Port Mux Control 4 This field controls the configuration for GPIO pin 4. 15:12 PMC3 RW - Port Mux Control 3 This field controls the configuration for GPIO pin 3. 11:8 PMC2 RW - Port Mux Control 2 This field controls the configuration for GPIO pin 2. 7:4 PMC1 RW - Port Mux Control 1 This field controls the configuration for GPIO pin 1. 3:0 PMC0 RW - Port Mux Control 0 This field controls the configuration for GPIO pin 0. 788 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 23: GPIO ADC Control (GPIOADCCTL), offset 0x530 This register is used to configure a GPIO pin as a source for the ADC trigger. Note that if the Port B GPIOADCCTL register is cleared, PB4 can still be used as an external trigger for the ADC. This is a legacy mode which allows code written for previous devices to operate on this microcontroller. GPIO ADC Control (GPIOADCCTL) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x530 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 ADCEN RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 ADCEN RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. ADC Trigger Enable Value Description 0 The corresponding pin is not used to trigger the ADC. 1 The corresponding pin is used to trigger the ADC. June 18, 2014 789 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 24: GPIO DMA Control (GPIODMACTL), offset 0x534 This register is used to configure a GPIO pin as a source for the μDMA trigger. GPIO DMA Control (GPIODMACTL) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x534 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset DMAEN RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DMAEN RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. μDMA Trigger Enable Value Description 0 The corresponding pin is not used to trigger the μDMA. 1 The corresponding pin is used to trigger the μDMA. 790 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 25: GPIO Select Interrupt (GPIOSI), offset 0x538 This register is used to enable individual interrupts for each pin. Note: This register is only available on Port P and Port Q. GPIO Select Interrupt (GPIOSI) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x538 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 SUM RW 0 RO 0 0 SUM RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Summary Interrupt Value Description 0 All port pin interrupts are OR'ed together to produce a summary interrupt. Note: 1 The OR'ed summary interrupt occurs on bit 0 of the GPIORIS register. For summary interrupt mode, software should set the GPIOIM register to 0xFF and mask the port pin interrupts 1 through 7 in the Interrupt Clear Enable (DISn) register (see “NVIC Register Descriptions” on page 153). When servicing this interrupt, write a 1 to the corresponding bit in the UNPENDn register to clear the pending interrupt in the NVIC and clear the GPIORIS register pin interrupt bits by setting the IC field of the GPIOICR register to 0xFF. Each pin has its own interrupt vector. June 18, 2014 791 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 26: GPIO 12-mA Drive Select (GPIODR12R), offset 0x53C The GPIODR12R register is the 12-mA drive control register. Each GPIO signal in the port can be individually configured without affecting the other pads. Note: This register has no effect on port pins PL6 and PL7 or PM[7:4]. GPIO 12-mA Drive Select (GPIODR12R) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x53C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 DRV12 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DRV12 RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Output Pad 12-mA Drive Enable Value Description 0 The drive for the corresponding GPIO pin is controlled by the GPIODR2R, GPIODR4R, and/or the GPIODR8R register. 1 The corresponding GPIO pin has 12-mA drive. This encoding is only valid if the GPIOPP EDE bit is set and the appropriate GPIOPC EDM bit field is programmed to 0x3. Note: Please refer to Table 10-3 on page 753 for information on how to configure the drive strength. Changes in the GPIODR2R, the GPIODR4R register and/or the GPIODR8R registers to configure 12 mA are effective on the next clock cycle. 792 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 27: GPIO Wake Pin Enable (GPIOWAKEPEN), offset 0x540 This register is used to configure K[7:4] as a wake enable source for the hibernation module. The wake level must be programmed in the GPIOWAKELVL register at offset 0x544. In order for this register configuration to become implemented, the WUUNLK bit needs to be set in the HIBIO register at offset 0x02C in the hibernation module. Note: This register is only available on Port K. GPIO Wake Pin Enable (GPIOWAKEPEN) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x540 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 WAKEP7 WAKEP6 WAKEP5 WAKEP4 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.000 7 WAKEP7 RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. K[7] Wake Enable Value Description 6 WAKEP6 RW 0 0 Wake-on level is not enabled. 1 Wake-on level is enabled. K[6] Wake Enable Value Description 0 Wake-on level is not enabled. 1 Wake-on level is enabled. June 18, 2014 793 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Bit/Field Name Type Reset 5 WAKEP5 RW 0 Description K[5] Wake Enable Value Description 4 WAKEP4 RW 0 0 Wake-on level is not enabled. 1 Wake-on level is enabled. K[4] Wake Enable Value Description 3:0 reserved RO 0 0 Wake-on level is not enabled. 1 Wake-on level is enabled. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 794 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 28: GPIO Wake Level (GPIOWAKELVL), offset 0x544 This register is used to configure the wake level for K[7:4] in the hibernation module. The wake source must be enabled in the GPIOWAKEPEN register at offset 0x540. In order for this register configuration to become implemented, the WUUNLK bit needs to be set in the HIBIO register at offset 0x02C in the hibernation module. Note: This register is only available on Port K. GPIO Wake Level (GPIOWAKELVL) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x544 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 reserved WAKELVL7 WAKELVL6 WAKELVL5 WAKELVL4 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.000 7 WAKELVL7 RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. K[7] Wake Level Value Description 6 WAKELVL6 RW 0 0 Wake level low 1 Wake level high K[6] Wake Level Value Description 0 Wake level low 1 Wake level high June 18, 2014 795 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Bit/Field Name Type Reset 5 WAKELVL5 RW 0 Description K[5] Wake Level Value Description 4 WAKELVL4 RW 0 0 Wake level low 1 Wake level high K[4] Wake Level Value Description 3:0 reserved RO 0 0 Wake level low 1 Wake level high Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 796 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 29: GPIO Wake Status (GPIOWAKESTAT), offset 0x548 This register indicates the GPIO wake event status. If a register bit has been set for K[7:4] , a wake event signal has been sent to the Hibernate module. Note: This register is only available on Port K. GPIO Wake Status (GPIOWAKESTAT) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0x548 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.000 7 STAT7 RO 0 RO 0 RO 0 7 6 5 4 STAT7 STAT6 STAT5 STAT4 RO 0 RO 0 RO 0 RO 0 reserved RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. K[7] Wake Status This is for future use. Value Description 6 STAT6 RO 0 0 Pin is not wake up source 1 Pin wake event asserted to hibernate module K[6] Wake Status This is for future use. Value Description 0 Pin is not wake up source 1 Pin wake event asserted to hibernate module June 18, 2014 797 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Bit/Field Name Type Reset 5 STAT5 RO 0 Description K[5] Wake Status This is for future use. Value Description 4 STAT4 RO 0 0 Pin is not wake up source 1 Pin wake event asserted to hibernate module K[4] Wake Status Value Description 3:0 reserved RO 0 0 Pin is not wake up source 1 Pin wake event asserted to hibernate module Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 798 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 30: GPIO Peripheral Property (GPIOPP), offset 0xFC0 The GPIOPP register provides information regarding the GPIO properties. GPIO Peripheral Property (GPIOPP) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFC0 Type RO, reset 0x0000.0001 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 EDE RO 1 Bit/Field Name Type Reset Description 31:1 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 EDE RO 0x1 Extended Drive Enable This bit specifies whether the extended drive capabilities are provided. Extended drive is configured by the EDM bits in the GPIOPC register. Value Description 0 No Extended Drive Capability provided. 1 Extended Drive Capability provided. June 18, 2014 799 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 31: GPIO Peripheral Configuration (GPIOPC), offset 0xFC4 This GPIOPC register controls the extended drive modes of the GPIO and must be configured before the GPIODRnR registers in order for extended drive mode to take effect. When the EDE bit in GPIOPP register is set and the EDMn bit field is non-zero, the GPIODRnR registers do not drive their default value, but instead output an incremental drive strength, which has an additive effect. This allows for more drive strength possibilities. When the EDE bit is set and the EDMn bit field is non-zero, the 2 mA driver is always enabled. Any bits enabled in the GPIODR4R register will add an additional 2 mA; any bits set in the GPIODR8R add an extra 4 mA of drive. The GPIODR12R register is only valid when the EDMn value is 0x3. For this encoding, setting a bit in the GPIODR12R register adds 4 mA of drive to the already existing 8 mA, for a 12 mA drive strength. Table 10-3 on page 753 shows the drive capability options. If EDMn is 0x00, then the GPIODR2R, GPIODR4R, and GPIODR8R function as stated in their default register description. Table 10-13. GPIO Drive Strength Options EDE (GPIOPP) X 1 1 1 EDMn (GPIOPC) 0x0 0x1 0x3 0x2 GPIODR12R (+4mA) N/A N/A GPIODR8R (+4mA) GPIODR4R (+2mA) GPIODR2R (2mA) Drive (mA) 0 0 1 2 0 1 0 4 1 0 0 8 0 0 N/A 2 0 1 N/A 4 1 0 N/A 6 1 1 N/A 8 0 0 0 N/A 2 0 0 1 N/A 4 0 1 0 N/A 6 0 1 1 N/A 8 1 1 0 N/A 10 1 1 1 N/A 12 1 0 N/A N/A N/A N/A N/A N/A N/A N/A 800 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller GPIO Peripheral Configuration (GPIOPC) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFC4 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset EDM7 Type Reset RW 0 EDM6 EDM5 EDM4 Bit/Field Name Type Reset 31:16 reserved RO 0x0000.000 15:14 EDM7 RW 0 EDM3 EDM2 EDM1 EDM0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Extended Drive Mode Bit 7 Same encoding as EDM0, but applies to bit 7 of GPIO port. 13:12 EDM6 RW 0 Extended Drive Mode Bit 6 Same encoding as EDM0, but applies to bit 6 of GPIO port. 11:10 EDM5 RW 0 Extended Drive Mode Bit 5 Same encoding as EDM0, but applies to bit 5 of GPIO port. 9:8 EDM4 RW 0 Extended Drive Mode Bit 4 Same encoding as EDM0, but applies to bit 4 of GPIO port. 7:6 EDM3 RW 0 Extended Drive Mode Bit 3 Same encoding as EDM0, but applies to bit 3 of GPIO port. 5:4 EDM2 RW 0 Extended Drive Mode Bit 2 Same encoding as EDM0, but applies to bit 2 of GPIO port. 3:2 EDM1 RW 0 Extended Drive Mode Bit 1 Same encoding as EDM0, but applies to bit 1 of GPIO port. June 18, 2014 801 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Bit/Field Name Type Reset 1:0 EDM0 RW 0 Description Extended Drive Mode Bit 0 This field controls extended drive modes of bit 0 of the GPIO port. Note that depending on the encoding used the GPIO drive strength control registers may change their decoding. Moreover, the write one, clear other register behavior may be disabled. Value Description 0x0 Drive values of 2, 4 and 8 mA are maintained. GPIO n Drive Select (GPIODRnR) registers function as normal. 0x1 An additional 6 mA option is provided. Write one, clear other behavior of GPIODDRnR registers is disabled. A 2 mA driver is always enabled; setting the corresponding GPIODR4R register bit adds 2 mA and setting the corresponding GPIODR8R register bit adds an additional 4 mA. 0x2 reserved 0x3 Additional drive strength options of 6, 10, and 12 mA are provided. The write one, clear other behavior of GPIODDRnR registers is disabled. A 2 mA driver is always enabled; setting the corresponding GPIODR4R register bit adds 2 mA and setting the corresponding GPIODR8R of GPIODR12R register bit adds an additional 4 mA. 802 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 32: GPIO Peripheral Identification 4 (GPIOPeriphID4), offset 0xFD0 The GPIOPeriphID4, GPIOPeriphID5, GPIOPeriphID6, and GPIOPeriphID7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 4 (GPIOPeriphID4) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFD0 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID4 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID4 RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [7:0] June 18, 2014 803 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 33: GPIO Peripheral Identification 5 (GPIOPeriphID5), offset 0xFD4 The GPIOPeriphID4, GPIOPeriphID5, GPIOPeriphID6, and GPIOPeriphID7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 5 (GPIOPeriphID5) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFD4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID5 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID5 RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [15:8] 804 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 34: GPIO Peripheral Identification 6 (GPIOPeriphID6), offset 0xFD8 The GPIOPeriphID4, GPIOPeriphID5, GPIOPeriphID6, and GPIOPeriphID7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 6 (GPIOPeriphID6) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFD8 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID6 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID6 RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [23:16] June 18, 2014 805 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 35: GPIO Peripheral Identification 7 (GPIOPeriphID7), offset 0xFDC The GPIOPeriphID4, GPIOPeriphID5, GPIOPeriphID6, and GPIOPeriphID7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 7 (GPIOPeriphID7) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFDC Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID7 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID7 RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [31:24] 806 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 36: GPIO Peripheral Identification 0 (GPIOPeriphID0), offset 0xFE0 The GPIOPeriphID0, GPIOPeriphID1, GPIOPeriphID2, and GPIOPeriphID3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 0 (GPIOPeriphID0) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFE0 Type RO, reset 0x0000.0061 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset reserved Type Reset PID0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID0 RO 0x61 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [7:0] Can be used by software to identify the presence of this peripheral. June 18, 2014 807 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 37: GPIO Peripheral Identification 1 (GPIOPeriphID1), offset 0xFE4 The GPIOPeriphID0, GPIOPeriphID1, GPIOPeriphID2, and GPIOPeriphID3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 1 (GPIOPeriphID1) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFE4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID1 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID1 RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [15:8] Can be used by software to identify the presence of this peripheral. 808 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 38: GPIO Peripheral Identification 2 (GPIOPeriphID2), offset 0xFE8 The GPIOPeriphID0, GPIOPeriphID1, GPIOPeriphID2, and GPIOPeriphID3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 2 (GPIOPeriphID2) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFE8 Type RO, reset 0x0000.0018 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID2 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID2 RO 0x18 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [23:16] Can be used by software to identify the presence of this peripheral. June 18, 2014 809 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 39: GPIO Peripheral Identification 3 (GPIOPeriphID3), offset 0xFEC The GPIOPeriphID0, GPIOPeriphID1, GPIOPeriphID2, and GPIOPeriphID3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register, used by software to identify the peripheral. GPIO Peripheral Identification 3 (GPIOPeriphID3) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFEC Type RO, reset 0x0000.0001 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset reserved Type Reset PID3 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID3 RO 0x01 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO Peripheral ID Register [31:24] Can be used by software to identify the presence of this peripheral. 810 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 40: GPIO PrimeCell Identification 0 (GPIOPCellID0), offset 0xFF0 The GPIOPCellID0, GPIOPCellID1, GPIOPCellID2, and GPIOPCellID3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register. The register is used as a standard cross-peripheral identification system. GPIO PrimeCell Identification 0 (GPIOPCellID0) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFF0 Type RO, reset 0x0000.000D 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 1 reserved Type Reset reserved Type Reset CID0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID0 RO 0x0D Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO PrimeCell ID Register [7:0] Provides software a standard cross-peripheral identification system. June 18, 2014 811 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 41: GPIO PrimeCell Identification 1 (GPIOPCellID1), offset 0xFF4 The GPIOPCellID0, GPIOPCellID1, GPIOPCellID2, and GPIOPCellID3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register. The register is used as a standard cross-peripheral identification system. GPIO PrimeCell Identification 1 (GPIOPCellID1) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFF4 Type RO, reset 0x0000.00F0 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 1 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset CID1 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID1 RO 0xF0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO PrimeCell ID Register [15:8] Provides software a standard cross-peripheral identification system. 812 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 42: GPIO PrimeCell Identification 2 (GPIOPCellID2), offset 0xFF8 The GPIOPCellID0, GPIOPCellID1, GPIOPCellID2, and GPIOPCellID3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register. The register is used as a standard cross-peripheral identification system. GPIO PrimeCell Identification 2 (GPIOPCellID2) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFF8 Type RO, reset 0x0000.0005 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 0 RO 1 reserved Type Reset reserved Type Reset CID2 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID2 RO 0x05 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO PrimeCell ID Register [23:16] Provides software a standard cross-peripheral identification system. June 18, 2014 813 Texas Instruments-Production Data General-Purpose Input/Outputs (GPIOs) Register 43: GPIO PrimeCell Identification 3 (GPIOPCellID3), offset 0xFFC The GPIOPCellID0, GPIOPCellID1, GPIOPCellID2, and GPIOPCellID3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register. The register is used as a standard cross-peripheral identification system. GPIO PrimeCell Identification 3 (GPIOPCellID3) GPIO Port A (AHB) base: 0x4005.8000 GPIO Port B (AHB) base: 0x4005.9000 GPIO Port C (AHB) base: 0x4005.A000 GPIO Port D (AHB) base: 0x4005.B000 GPIO Port E (AHB) base: 0x4005.C000 GPIO Port F (AHB) base: 0x4005.D000 GPIO Port G (AHB) base: 0x4005.E000 GPIO Port H (AHB) base: 0x4005.F000 GPIO Port J (AHB) base: 0x4006.0000 GPIO Port K (AHB) base: 0x4006.1000 GPIO Port L (AHB) base: 0x4006.2000 GPIO Port M (AHB) base: 0x4006.3000 GPIO Port N (AHB) base: 0x4006.4000 GPIO Port P (AHB) base: 0x4006.5000 GPIO Port Q (AHB) base: 0x4006.6000 Offset 0xFFC Type RO, reset 0x0000.00B1 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 RO 1 reserved Type Reset reserved Type Reset CID3 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID3 RO 0xB1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPIO PrimeCell ID Register [31:24] Provides software a standard cross-peripheral identification system. 814 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 11 External Peripheral Interface (EPI) The External Peripheral Interface is a high-speed parallel bus for external peripherals or memory. It has several modes of operation to interface gluelessly to many types of external devices. The External Peripheral Interface is similar to a standard microprocessor address/data bus, except that it must typically be connected to just one type of external device. Enhanced capabilities include µDMA support, clocking control and support for external FIFO buffers. The EPI has the following features: ■ 8/16/32-bit dedicated parallel bus for external peripherals and memory ■ Memory interface supports contiguous memory access independent of data bus width, thus enabling code execution directly from SDRAM, SRAM and Flash memory ■ Blocking and non-blocking reads ■ Separates processor from timing details through use of an internal write FIFO ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for read and write – Read channel request asserted by programmable levels on the internal Non-Blocking Read FIFO (NBRFIFO) – Write channel request asserted by empty on the internal Write FIFO (WFIFO) The EPI supports three primary functional modes: Synchronous Dynamic Random Access Memory (SDRAM) mode, Traditional Host-Bus mode, and General-Purpose mode. The EPI module also provides custom GPIOs; however, unlike regular GPIOs, the EPI module uses a FIFO in the same way as a communication mechanism and is speed-controlled using clocking. ■ Synchronous Dynamic Random Access Memory (SDRAM) mode – Supports x16 (single data rate) SDRAM at up to 60 MHz – Supports low-cost SDRAMs up to 64 MB (512 megabits) – Includes automatic refresh and access to all banks/rows – Includes a Sleep/Standby mode to keep contents active with minimal power draw – Multiplexed address/data interface for reduced pin count ■ Host-Bus mode – Traditional x8 and x16 MCU bus interface capabilities – Similar device compatibility options as PIC, ATmega, 8051, and others – Access to SRAM, NOR Flash memory, and other devices, with up to 1 MB of addressing in non-multiplexed mode and 256 MB in multiplexed mode (512 MB in Host-Bus 16 mode with no byte selects) June 18, 2014 815 Texas Instruments-Production Data External Peripheral Interface (EPI) – Support for up to 512 Mb PSRAM in quad chip select mode, with dedicated configuration register read and write enable. – Support of both muxed and de-muxed address and data – Access to a range of devices supporting the non-address FIFO x8 and x16 interface variant, with support for external FIFO (XFIFO) EMPTY and FULL signals – Speed controlled, with read and write data wait-state counters – Support for read/write burst mode to Host Bus – Multiple chip select modes including single, dual, and quad chip selects, with and without ALE – External iRDY signal provided for stall capability of reads and writes – Manual chip-enable (or use extra address pins) ■ General-Purpose mode – Wide parallel interfaces for fast communications with CPLDs and FPGAs – Data widths up to 32 bits – Data rates up to 150 MB/second – Optional "address" sizes from 4 bits to 20 bits – Optional clock output, read/write strobes, framing (with counter-based size), and clock-enable input ■ General parallel GPIO – 1 to 32 bits, FIFOed with speed control – Useful for custom peripherals or for digital data acquisition and actuator controls 11.1 EPI Block Diagram Figure 11-1 on page 817 provides a block diagram of a TM4C1294NCPDT EPI module. 816 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 11-1. EPI Block Diagram General Parallel GPIO NBRFIFO 8 x 32 bits WFIFO SDRAM 4 x 32 bits AHB Bus Interface With DMA AHB EPI 31:0 Host Bus Baud Rate Control (Clock) Wide Parallel Interface 11.2 Signal Description The following table lists the external signals of the EPI controller and describes the function of each. The EPI controller signals are alternate functions for GPIO signals and default to be GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the GPIO pin placement for the EPI signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the EPI controller function. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the EPI signals to the specified GPIO port pins. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Table 11-1. External Peripheral Interface Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description EPI0S0 18 29 PK0 (15) PH0 (15) I/O TTL EPI module 0 signal 0. EPI0S1 19 30 PK1 (15) PH1 (15) I/O TTL EPI module 0 signal 1. EPI0S2 20 31 PK2 (15) PH2 (15) I/O TTL EPI module 0 signal 2. EPI0S3 21 32 PK3 (15) PH3 (15) I/O TTL EPI module 0 signal 3. EPI0S4 22 PC7 (15) I/O TTL EPI module 0 signal 4. EPI0S5 23 PC6 (15) I/O TTL EPI module 0 signal 5. EPI0S6 24 PC5 (15) I/O TTL EPI module 0 signal 6. EPI0S7 25 PC4 (15) I/O TTL EPI module 0 signal 7. June 18, 2014 817 Texas Instruments-Production Data External Peripheral Interface (EPI) Table 11-1. External Peripheral Interface Signals (128TQFP) (continued) Pin Name 11.3 Pin Number Pin Mux / Pin Assignment EPI0S8 40 Pin Type Buffer Type Description PA6 (15) I/O TTL EPI module 0 signal 8. EPI0S9 41 PA7 (15) I/O TTL EPI module 0 signal 9. EPI0S10 50 PG1 (15) I/O TTL EPI module 0 signal 10. EPI0S11 49 PG0 (15) I/O TTL EPI module 0 signal 11. EPI0S12 75 PM3 (15) I/O TTL EPI module 0 signal 12. EPI0S13 76 PM2 (15) I/O TTL EPI module 0 signal 13. EPI0S14 77 PM1 (15) I/O TTL EPI module 0 signal 14. EPI0S15 78 PM0 (15) I/O TTL EPI module 0 signal 15. EPI0S16 81 PL0 (15) I/O TTL EPI module 0 signal 16. EPI0S17 82 PL1 (15) I/O TTL EPI module 0 signal 17. EPI0S18 83 PL2 (15) I/O TTL EPI module 0 signal 18. EPI0S19 84 PL3 (15) I/O TTL EPI module 0 signal 19. EPI0S20 5 PQ0 (15) I/O TTL EPI module 0 signal 20. EPI0S21 6 PQ1 (15) I/O TTL EPI module 0 signal 21. EPI0S22 11 PQ2 (15) I/O TTL EPI module 0 signal 22. EPI0S23 27 PQ3 (15) I/O TTL EPI module 0 signal 23. EPI0S24 60 PK7 (15) I/O TTL EPI module 0 signal 24. EPI0S25 61 PK6 (15) I/O TTL EPI module 0 signal 25. EPI0S26 85 PL4 (15) I/O TTL EPI module 0 signal 26. EPI0S27 91 PB2 (15) I/O TTL EPI module 0 signal 27. EPI0S28 92 PB3 (15) I/O TTL EPI module 0 signal 28. EPI0S29 103 109 PP2 (15) PN2 (15) I/O TTL EPI module 0 signal 29. EPI0S30 104 110 PP3 (15) PN3 (15) I/O TTL EPI module 0 signal 30. EPI0S31 62 PK5 (15) I/O TTL EPI module 0 signal 31. EPI0S32 63 PK4 (15) I/O TTL EPI module 0 signal 32. EPI0S33 86 PL5 (15) I/O TTL EPI module 0 signal 33. EPI0S34 111 PN4 (15) I/O TTL EPI module 0 signal 34. EPI0S35 112 PN5 (15) I/O TTL EPI module 0 signal 35. Functional Description The EPI controller provides a glueless, programmable interface to a variety of common external peripherals such as SDRAM x 16, Host Bus x8 and x16 devices, RAM, NOR Flash memory, CPLDs and FPGAs. In addition, the EPI controller provides custom GPIO that can use a FIFO with speed control by using either the internal write FIFO (WFIFO) or the non-blocking read FIFO (NBRFIFO). The WFIFO can hold 4 words of data that are written to the external interface at the rate controlled by the EPI Main Baud Rate (EPIBAUD) registers. The NBRFIFO can hold 8 words of data and samples at the rate controlled by the EPIBAUD register. The EPI controller provides predictable operation and thus has an advantage over regular GPIO which has more variable timing due to on-chip bus arbitration and delays across bus bridges. Blocking reads stall the CPU until the transaction completes. Non-blocking reads are performed in the background and allow the processor 818 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller to continue operation. In addition, write data can also be stored in the WFIFO to allow multiple writes with no stalls. Note: Both the WTAV bit field in the EPIWFIFOCNT register and the WBUSY bit in the EPISTAT register must be polled to determine if there is a current write transaction from the WFIFO. If both of these bits are clear, then a new bus access may begin. Main read and write operations can be performed in subsets of the range 0x6000.0000 to 0xDFFF.FFFF. A read from an address mapped location uses the offset and size to control the address and size of the external operation. When performing a multi-value load, the read is done as a burst (when available) to maximize performance. A write to an address mapped location uses the offset and size to control the address and size of the external operation. When performing a multi-value store, the write is done as a burst (when available) to maximize performance. 11.3.1 Master Access to EPI The following lists the Bus Masters which have access to the EPI: ■ CPU ■ µDMA 11.3.2 Non-Blocking Reads The EPI Controller supports a special kind of read called a non-blocking read, also referred to as a posted read. Where a normal read stalls the processor or μDMA until the data is returned, a non-blocking read is performed in the background. A non-blocking read is configured by writing the start address into a EPIRADDRn register, the size per transaction into a EPIRSIZEn register, and then the count of operations into a EPIRPSTDn register. After each read is completed, the result is written into the NBRFIFO and the EPIRADDRn register is incremented by the size (1, 2, or 4). The three most significant bits of EPIRADDRn register are only relevant in the Host Bus multi-chip select mode when they are used to enable the different chip selects. If the NBRFIFO is filled, then the reads pause until space is made available. The NBRFIFO can be configured to interrupt the processor or trigger the μDMA based on fullness using the EPIFIFOLVL register. By using the trigger/interrupt method, the μDMA (or processor) can keep space available in the NBRFIFO and allow the reads to continue unimpeded. When performing non-blocking reads, the SDRAM controller issues two additional read transactions after the burst request is terminated. The data for these additional transfers is discarded. This situation is transparent to the user other than the additional EPI bus activity and can safely be ignored. Two non-blocking read register sets are available to allow sequencing and ping-pong use. When one completes, the other then activates. So, for example, if 20 words are to be read from 0x100 and 10 words from 0x200, the EPIRPSTD0 register can be set up with the read from 0x100 (with a count of 20), and the EPIRPSTD1 register can be set up with the read from 0x200 (with a count of 10). When EPIRPSTD0 finishes (count goes to 0), the EPIRPSTD1 register then starts its operation. The NBRFIFO has then passed 30 values. When used with the μDMA, it may transfer 30 values (simple sequence), or the primary/alternate model may be used to handle the first 20 in one way and the second 10 in another. It is also possible to reload the EPIRPSTD0 register when it is finished (and the EPIRPSTD1 register is active); thereby, keeping the interface constantly busy. To cancel a non-blocking read, the EPIRPSTDn register is cleared. Care must be taken, however if the register set was active to drain away any values read into the NBRFIFO and ensure that any read in progress is allowed to complete. June 18, 2014 819 Texas Instruments-Production Data External Peripheral Interface (EPI) To ensure that the cancel is complete, the following algorithm is used (using the EPIRPSTD0 register for example): EPIRPSTD0 = 0; while ((EPISTAT & 0x11) == 0x10) ; // we are active and busy // if here, then other one is active or interface no longer busy cnt = (EPIRADDR0 – original_address) / EPIRSIZE0; // count of values read cnt -= values_read_so_far; // cnt is now number left in FIFO while (cnt--) value = EPIREADFIFO; // drain The above algorithm can be optimized in code; however, the important point is to wait for the cancel to complete because the external interface could have been in the process of reading a value when the cancel came in, and it must be allowed to complete. 11.3.3 DMA Operation The µDMA can be used to achieve maximum transfer rates on the EPI through the NBRFIFO and the WFIFO. The µDMA has one channel for write and one for read. For writes, the EPI DMA Transmit Count (EPIDMATXCNT) register is programmed with the total number of transfers by the µDMA. An equivalent value is programmed into the DMA Channel Control Word (DMACHCTL) register of the uDMA at offset 0x008. A µDMA request is asserted by the EPI WRFIFO when the TXCNT value of the EPIDMATXCNT register is greater than zero and the WTAV bit field of the EPIWFIFOCNT register is less than the programmed threshold trigger, WRFIFO, of the EPIFIFOLVL register. The write channel continues to write data until the TXCNT value in the EPIDMATXCNT register is zero. Note: When the WRFIFO bit in the EPIFIFOLVL register is set to 0x4 and the application bursts four words to an empty FIFO, the WRFIFO trigger may or may not deassert depending on if all four words were written to the WRFIFO or if the first word was passed immediately to the function requiring it. Thus, the application may not see the WRRIS bit in the EPIRIS register clear on a burst of four words. The non-blocking read channel copies values from the NBRFIFO when the NBRFIFO is at the level specified by the EPIFIFOLVL register. For non-blocking reads, the start address, the size per transaction, and the count of elements must be programmed in the µDMA. Note that both non-blocking read register sets can be used, and they fill the NBRFIFO such that one runs to completion, then the next one starts (they do not interleave). Using the NBRFIFO provides the best possible transfer rate. For blocking reads, the µDMA software channel (or another unused channel) is used for memory-to-memory transfers (or memory to peripheral, where some other peripheral is used). In this situation, the µDMA stalls until the read is complete and is not able to service another channel until the read is done. As a result, the arbitration size should normally be programmed to one access at a time. The µDMA controller can also transfer from and to the NBRFIFO and the WFIFO using the µDMA software channel in memory mode, however, the µDMA is stalled once the NBRFIFO is empty or the WFIFO is full. Note that when the µDMA controller is stalled, the core continues operation. See “Micro Direct Memory Access (μDMA)” on page 678 for more information on configuring the µDMA. 820 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The size of the FIFOs must be taken into consideration when configuring the µDMA to transfer data to and from the EPI. The arbitration size should be 4 or less when writing to EPI address space and 8 or less when reading from EPI address space. 11.4 Initialization and Configuration To enable and initialize the EPI controller, the following steps are necessary: 1. Enable the EPI module using the RCGCEPI register. See page 386. 2. Enable the clock to the appropriate GPIO module via the RCGCGPIO register. See page 382. To find out which GPIO port to enable, refer to “Signal Description” on page 817. 3. Set the GPIO AFSEL bits for the appropriate pins. See page 770. To determine which GPIOs to configure, see Table 26-4 on page 1797. 4. Configure the GPIO current level and/or slew rate as specified for the mode selected. See page 772 and page 780. 5. Configure the PMCn fields in the GPIOPCTL register to assign the EPI signals to the appropriate pins. See page 787 and Table 26-5 on page 1808. 6. Select the mode for the EPI block to SDRAM, HB8, HB16, or general parallel use, using the MODE field in the EPI Configuration (EPICFG) register. Set the mode-specific details (if needed) using the appropriate mode configuration EPI Host Bus Configuration (EPIHBnCFGn) registers for the desired chip-select configuration. Set the EPI Main Baud Rate (EPIBAUD) and EPI Main Baud Rate 2 (EPIBAUD2) register if the baud rate must be slower than the system clock rate. 7. Configure the address mapping using the EPI Address Map (EPIADDRMAP) register. The selected start address and range is dependent on the type of external device and maximum address (as appropriate). For example, for a 512-megabit SDRAM, program the ERADR field to 0x1 for address 0x6000.0000 or 0x2 for address 0x8000.0000; and program the ERSZ field to 0x3 for 256 MB. If using General-Purpose mode and no address at all, program the EPADR field to 0x1 for address 0xA000.0000 or 0x2 for address 0xC000.0000; and program the EPSZ field to 0x0 for 256 bytes. 8. To read or write directly, use the mapped address area (configured with the EPIADDRMAP register). Up to 4 or 5 writes can be performed at once without blocking. Each read is blocked until the value is retrieved. 9. To perform a non-blocking read, see “Non-Blocking Reads” on page 819. Note: The application should not attempt to access externally until eight system clock cycles after the EPI has been fully configured. Note: Once a MODE field has been programmed in the EPICFG register, the application should reset all configuration registers before re-programming to a new MODE value. The following sub-sections describe the initialization and configuration for each of the modes of operation. Care must be taken to initialize everything properly to ensure correct operation. Control of the GPIO states is also important, as changes may cause the external device to interpret pin states as actions or commands (see “Register Descriptions” on page 758). Normally, a pull-up or pull-down is needed on the board to at least control the chip-select or chip-enable as the TM4C1294NCPDT GPIOs come out of reset in tri-state. June 18, 2014 821 Texas Instruments-Production Data External Peripheral Interface (EPI) 11.4.1 EPI Interface Options There are a variety of memories and peripherals that can interface to the EPI module. Table 11-2 on page 822 shows the various configurations with their maximum performance. Table 11-2. EPI Interface Options Interface 11.4.2 Maximum Frequency Single SDRAM 60 MHz Single SRAM 60 MHz Single PSRAM without iRDY signal use 55 MHz Single PSRAM with iRDY signal use 52 MHz FPGAs, CPLDs, etc using General Purpose Mode 60 MHz Memory configurations with 2 chip selects 40 MHz Memory configurations with 4 chip selects 20 MHz SDRAM Mode When activating the SDRAM mode, it is important to consider a few points: 1. Generally, it takes over 100 μs from when the mode is activated to when the first operation is allowed. The SDRAM controller begins the SDRAM initialization sequence as soon as the mode is selected and enabled via the EPICFG register. It is important that the GPIOs are properly configured before the SDRAM mode is enabled, as the EPI controller is relying on the GPIO block's ability to drive the pins immediately. As part of the initialization sequence, the LOAD MODE REGISTER command is automatically sent to the SDRAM with a value of 0x27, which sets a CAS latency of 2 and a full page burst length. 2. The INITSEQ bit in the EPI Status (EPISTAT) register can be checked to determine when the initialization sequence is complete. 3. When using a frequency range and/or refresh value other than the default value, it is important to configure the FREQ and RFSH fields in the EPI SDRAM Configuration (EPISDRAMCFG) register shortly after activating the mode. After the 100-μs startup time, the EPI block must be configured properly to keep the SDRAM contents stable. 4. The SLEEP bit in the EPISDRAMCFG register may be configured to put the SDRAM into a low-power self-refreshing state. It is important to note that the SDRAM mode must not be disabled once enabled, or else the SDRAM is no longer clocked and the contents are lost. 5. Before entering SLEEP mode, make sure all non-blocking reads and normal reads and writes have completed. If the system is running at 30 to 50 MHz, wait 2 EPI clocks after clearing the SLEEP bit before executing non-blocking reads, or normal reads and writes. If the system is configured to greater than 50 MHz, wait 5 EPI clocks before read and write transactions. For all other configurations, wait 1 EPI clock. The SIZE field of the EPISDRAMCFG register must be configured correctly based on the amount of SDRAM in the system. The FREQ field must be configured according to the value that represents the range being used. Based on the range selected, the number of external clocks used between certain operations (for example, PRECHARGE or ACTIVATE) is determined. If a higher frequency is given than is used, then the only downside is that the peripheral is slower (uses more cycles for these delays). If a lower frequency is given, incorrect operation occurs. 822 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller See “External Peripheral Interface (EPI)” on page 1853 for timing details for the SDRAM mode. 11.4.2.1 External Signal Connections Table 11-3 on page 823 defines how EPI module signals should be connected to SDRAMs. The table applies when using a x16 SDRAM up to 512 megabits. Note that the EPI signals must use 8-mA drive when interfacing to SDRAM, see page 774. Any unused EPI controller signals can be used as GPIOs or another alternate function. Table 11-3. EPI SDRAM x16 Signal Connections a EPI Signal SDRAM Signal EPI0S0 A0 D0 EPI0S1 A1 D1 EPI0S2 A2 D2 EPI0S3 A3 D3 EPI0S4 A4 D4 EPI0S5 A5 D5 EPI0S6 A6 D6 EPI0S7 A7 D7 EPI0S8 A8 D8 EPI0S9 A9 D9 EPI0S10 A10 D10 EPI0S11 A11 D11 EPI0S12 b A12 D12 EPI0S13 BA0 D13 EPI0S14 BA1 D14 EPI0S15 D15 EPI0S16 DQML EPI0S17 DQMH EPI0S18 CASn EPI0S19 RASn EPI0S20-EPI0S27 not used EPI0S28 WEn EPI0S29 CSn EPI0S30 CKE EPI0S31 CLK a. If two signals are listed, connect the EPI signal to both pins. b. Only for 256/512 megabit SDRAMs. 11.4.2.2 Refresh Configuration The refresh count is based on the external clock speed and the number of rows per bank as well as the refresh period. The RFSH field represents how many external clock cycles remain before an AUTO-REFRESH is required. The normal formula is: RFSH = (tRefresh_us / number_rows) / ext_clock_period A refresh period is normally 64 ms, or 64000 μs. The number of rows is normally 4096 or 8192. The ext_clock_period is a value expressed in μsec and is derived by dividing 1000 by the clock speed June 18, 2014 823 Texas Instruments-Production Data External Peripheral Interface (EPI) expressed in MHz. So, 50 MHz is 1000/50=20 ns, or 0.02 μs. A typical SDRAM is 4096 rows per bank if the system clock is running at 50 MHz with an EPIBAUD register value of 0: RFSH = (64000/4096) / 0.02 = 15.625 μs / 0.02 μs = 781.25 The default value in the RFSH field is 750 decimal or 0x2EE to allow for a margin of safety and providing 15 μs per refresh. It is important to note that this number should always be smaller or equal to what is required by the above equation. For example, if running the external clock at 25 MHz (40 ns per clock period), 390 is the highest number that may be used. Note that the external clock may be 25 MHz when the system clock is 25 MHz or when the system clock is 50 MHz and configuring the COUNT0 field in the EPIBAUD register to 1 (divide by 2). If a number larger than allowed is used, the SDRAM is not refreshed often enough, and data is lost. 11.4.2.3 Bus Interface Speed The EPI Controller SDRAM interface can operate up to 60 MHz. The COUNT0 field in the EPIBAUD register configures the speed of the EPI clock. For system clock (SysClk) speeds up to 60 MHz, the COUNT0 field can be 0x0000, and the SDRAM interface can run at the same speed as SysClk. However, if SysClk is running at higher speeds, the bus interface can run only as fast as half speed, and the COUNT0 field must be configured to at least 0x0001. 11.4.2.4 Non-Blocking Read Cycle Figure 11-2 on page 824 shows a non-blocking read cycle of n halfwords; n can be any number greater than or equal to 1. The cycle begins with the Activate command and the row address on the EPI0S[15:0] signals. With the programmed CAS latency of 2, the Read command with the column address on the EPI0S[15:0] signals follows after 2 clock cycles. Following one more NOP cycle, data is read in on the EPI0S[15:0] signals on every rising clock edge. The Burst Terminate command is issued during the cycle when the next-to-last halfword is read in. The DQMH and DQML signals are deasserted after the last halfword of data is received; the CSn signal deasserts on the following clock cycle, signaling the end of the read cycle. At least one clock period of inactivity separates any two SDRAM cycles. Figure 11-2. SDRAM Non-Blocking Read Cycle CLK (EPI0S31) CKE (EPI0S30) CSn (EPI0S29) WEn (EPI0S28) RASn (EPI0S19) CASn (EPI0S18) DQMH, DQML (EPI0S [17:16]) AD [15:0] (EPI0S [15:0]) Row Activate Column NOP Read Data 0 Data 1 ... Data n Burst Term NOP AD [15:0] driven in AD [15:0] driven out AD [15:0] driven out 824 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 11.4.2.5 Normal Read Cycle Figure 11-3 on page 825 shows a normal read cycle of n halfwords; n can be 1 or 2. The cycle begins with the Activate command and the row address on the EPI0S[15:0] signals. With the programmed CAS latency of 2, the Read command with the column address on the EPI0S[15:0] signals follows after 2 clock cycles. Following one more NOP cycle, data is read in on the EPI0S[15:0] signals on every rising clock edge. The DQMH, DQML, and CSn signals are deasserted after the last halfword of data is received, signaling the end of the cycle. At least one clock period of inactivity separates any two SDRAM cycles. Figure 11-3. SDRAM Normal Read Cycle CLK (EPI0S31) CKE (EPI0S30) CSn (EPI0S29) WEn (EPI0S28) RASn (EPI0S19) CASn (EPI0S18) DQMH, DQML (EPI0S [17:16]) AD [15:0] (EPI0S [15:0]) Row Activate Column NOP Read Data 0 Data 1 NOP AD [15:0] driven in AD [15:0] driven out 11.4.2.6 AD [15:0] driven out Write Cycle Figure 11-4 on page 826 shows a write cycle of n halfwords; n can be any number greater than or equal to 1. The cycle begins with the Activate command and the row address on the EPI0S[15:0] signals. With the programmed CAS latency of 2, the Write command with the column address on the EPI0S[15:0] signals follows after 2 clock cycles. When writing to SDRAMs, the Write command is presented with the first halfword of data. Because the address lines and the data lines are multiplexed, the column address is modified to be (programmed address -1). During the Write command, the DQMH and DQML signals are high, so no data is written to the SDRAM. On the next clock, the DQMH and DQML signals are asserted, and the data associated with the programmed address is written. The Burst Terminate command occurs during the clock cycle following the write of the last halfword of data. The WEn, DQMH, DQML, and CSn signals are deasserted after the last halfword of data is received, signaling the end of the access. At least one clock period of inactivity separates any two SDRAM cycles. June 18, 2014 825 Texas Instruments-Production Data External Peripheral Interface (EPI) Figure 11-4. SDRAM Write Cycle CLK (EPI0S31) CKE (EPI0S30) CSn (EPI0S29) WEn (EPI0S28) RASn (EPI0S19) CASn (EPI0S18) DQMH, DQML (EPI0S [17:16]) AD [15:0] (EPI0S [15:0]) Row Column-1 Activate NOP Data 0 Data 1 ... Data n Burst Term Write AD [15:0] driven out AD [15:0] driven out 11.4.3 Host Bus Mode Host Bus supports the traditional 8-bit and 16-bit interfaces popularized by the 8051 devices and SRAM devices, as well as PSRAM and NOR Flash memory. This interface is asynchronous and uses strobe pins to control activity. Addressable memory can be doubled using Host Bus-16 mode as it performs half-word accesses. The EPI0S0 is the LSB of the address and is equivalent to the internal Cortex-M4 A1 address. EPI0S0 should be connected to A0 of 16-bit memories. 11.4.3.1 Control Pins The main three strobes are Address Latch Enable (ALE), Write (WRn), and Read (RDn, sometimes called OEn). Note that the timings are designed for older logic and so are hold-time versus setup-time specific. The polarity of the read and write strobes can be active High or active Low by clearing or setting the RDHIGH and WRHIGH bits in the EPI Host-Bus n Configuration (EPIHBnCFGn) register. The ALE can be changed to an active-low chip select signal, CSn, through the EPIHBnCFGn register. The ALE is best used for Host-Bus muxed mode in which EPI address and data pins are shared. All Host-Bus accesses have an address phase followed by a data phase. The ALE indicates to an external latch to capture the address then hold it until the data phase. The polarity of the ALE can be active High or Low by clearing or setting the ALEHIGH bit in the EPI Host-Bus n Configuration (EPIHBnCFGn) register. CSn is best used for Host-Bus unmuxed mode in which EPI address and data pins are separate. The CSn indicates when the address and data phases of a read or write access are occurring. Both the ALE and the CSn modes can be enhanced to access four external devices using settings in the EPIHBnCFGn register. PSRAM accesses must use both ALE and CSn . Wait states can be added to the data phase of the access using the WRWS and RDWS bits in the EPIHBnCFGn register. Additionally, within these wait state options, the WRWSM and RDWSM bit of the EPIHBnTIMEn register can be set to reduce the given wait states by 1 EPI clock cycle for finer granularity. For FIFO mode, the ALE is not used, and two input holds are optionally supported to gate input and output to what the XFIFO can handle. FIFO mode is only applicable in EPI asynchronous mode. Host-Bus 8 and Host-Bus 16 modes are very configurable. The user has the ability to connect 1,2, or 4 external devices to the EPI signals, as well as control whether byte select signals are provided in HB16 mode. These capabilities depend on the configuration of the MODE field in the EPIHBnCFG 826 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller register, the CSCFG field and the CSCFGEXT bit in the EPIHBnCFGn register, and the BSEL bit in the EPIHB16CFG register. The CSCFGEXT bit extends the chip select configuration possibilities by providing the most significant bit of the CSCFG field. Refer to Table 11-4 on page 827 for the possible ALE and chip select options that can be programmed by the combination of the CSCFGEXT and CSCFG bits. Note that CSCFGEXT is the most significant bit. Table 11-4. CSCFGEXT + CSCFG Encodings Value Description 0x0 ALE Configuration EPI0S30 is used as an address latch (ALE). The ALE signal is generally used when the address and data are muxed (MODE field in the EPIHB8CFG register is 0x0). The ALE signal is used by an external latch to hold the address through the bus cycle. 0x1 CSn Configuration EPI0S30 is used as a Chip Select (CSn). When using this mode, the address and data are generally not muxed (MODE field in the EPIHB8CFG register is 0x1). However, if address and data muxing is needed, the WR signal (EPI0S29) and the RD signal (EPI0S28) can be used to latch the address when CSn is low. 0x2 Dual CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. This configuration can be used for a RAM bank split between 2 devices as well as when using both an external RAM and an external peripheral. 0x3 ALE with Dual CSn Configuration EPI0S30 is used as address latch (ALE), EPI0S27 is used as CS1n, and EPI0S26 is used as CS0n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. 0x4 ALE with Single CSn Configuration EPI0S30 is used as address latch (ALE) and EPI0S27 is used as CSn. 0x5 Quad CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. EPI0S34 is used as CS2n and EPI0S33 is used as CS3n. 0x6 ALE with Quad CSn Configuration EPI0S30 is ALE, EPI0S26 is CS0n and EPI0S27 is used as CS1n. EPI0S34 is used as CS2n and EPI0S33 is used as CS3n. 0x7 Reserved If one of the Dual-Chip-Select modes is selected (CSCFGEXT is 0x0 and CSCFG is 0x2 or 0x3 in the EPIHBnCFGn register), both chip selects can share the peripheral, code, or the memory space, or one chip select can use the peripheral space and the other can use the memory or code space. In the EPIADDRMAP register, if the EPADR field is not 0x0, the ECADR field is 0x0, and the ERADR field is 0x0, then the address specified by EPADR is used for both chip selects, with CS0n being asserted when the MSB of the address range is 0 and CS1n being asserted when the MSB of the address range is 1. If the ERADR field is not 0x0, the ECADR field is 0x0, and the EPADR field is 0x0, then the address specified by ERADR is used for both chip selects, with the MSB performing the same delineation. If both the EPADR and the ERADR are not 0x0, and the ECADR field is 0x0 and the EPI is configured for dual-chip selects, then CS0n is asserted for either address range defined by EPADR and CS1n is asserted for either address range defined by ERADR. The two chip selects can also be shared between the code space and memory or peripheral space. If the ECADR field is 0x1, ERADR field is 0x0, and the EPADR field is not 0x0, then CS0n is asserted for the address range defined by ECADR and CS1n is asserted for either address range defined by EPADR. If the ECADR field is 0x1, EPADR field is 0x0, and the ERADR field is not 0x0, then CS0n is asserted for the address range defined by ECADR and CS1n is asserted for either address range defined by ERADR. June 18, 2014 827 Texas Instruments-Production Data External Peripheral Interface (EPI) In quad chip select mode (CSCFGEXT is 0x1 and CSCFG is 0x1 or 0x2 in the EPIHBnCFG2 register), both the peripheral and the memory space must be enabled. In the EPIADDRMAP register, the EPADR field is 0x3, the ERADR field is 0x3, and the ECADR field is 0x0. With this configuration, CS0n asserts for the address range beginning at 0x6000.0000, CS1n asserts for 0x8000.0000, CS2n for 0xA000.0000, and CS3n for 0xC000.0000. Table 11-5 on page 828 gives a detailed explanation of chip select address range mappings based on combinations of enabled peripheral and memory space. Note: Only one memory area can be mapped to a single chip select. Enabling multiple memory areas for one chip select may produce unexpected results. Table 11-5. Dual- and Quad- Chip Select Address Mappings Chip Select Mode ERADR EPADR ECADR a CS0 CS1 CS2 CS3 Dual-chip select 0x0 0x1 or 0x2 0x0 EPADR defined address range (0xA000.000 or 0xC000.0000) EPADR defined address N/A range (0xA000.000 or 0xC000.0000) N/A Dual-chip select 0x1 or 0x2 0x0 0x0 ERADR defined address range (0x6000.000 or 0x8000.000) ERADR defined address N/A range (0x6000.000 or 0x8000.000) N/A Dual-chip select 0x1 or 0x2 0x1 or 0x2 0x0 EPADR defined address range (0xA000.000 or 0xC000.0000) ERADR defined address N/A range (0x6000.000 or 0x8000.000) N/A Dual-chip select 0x0 0x1 or 0x2 0x1 ECADR defined address range (0x1000.000) EPADR defined address N/A range (0xA000.0000 or 0xC000.0000) N/A Dual-chip select 0x1 or 0x2 0x0 0x1 ECADR defined address range (0x1000.000) ERADR defined address N/A range (0x6000.000 or 0x8000.000) N/A Quad-chip select 0x3 0x3 0x0 0x6000.0000 0x8000.0000 0xA000.0000 0xC000.0000 a. When CS0 & CS1 share address space, CS0 asserts when the MSB of the address is 0 and CS1, when the MSB of the address is '1.' The MODE field of the EPIHBnCFGn registers configure the interface for the chip selects, which support ADMUX or ADNOMUX. See Table 11-6 on page 829 for details on which configuration register controls each chip select. If the CSBAUD bit is clear, all chip selects are configured by the MODE bit field of the EPIHBnCFG register. If the CSBAUD bit in the EPIHBnCFG2 register is set in Dual-chip select mode, the 2 chip selects can use different clock frequencies, wait states and strobe polarity. If the CSBAUD bit is clear, both chip selects use the clock frequency, wait states, and strobe polarity defined for CS0n. Additionally, if the CSBAUD bit is set, the two chip selects can use different interface modes. If any interface modes are programmed to ADMUX, then dual chip select mode must include the ALE capability. In quad chip select mode, if the CSBAUD bit in the EPIHBnCFG2 register is set, the 4 chip selects can use different clock frequencies, wait states and strobe polarity. If the CSBAUD bit is clear, all chip selects use the clock frequency, wait states, and strobe polarity defined for CS0n. If the CSBAUD bit is set, the four chip selects can use different interface modes. 828 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 11-6. Chip Select Configuration Register Assignment a Configuration Register Corresponding Chip Select EPIHBnCFG CS0n EPIHBnCFG2 CS1n EPIHBnCFG3 CS2n EPIHBnCFG4 CS3n a. If the CSBAUD bit in the EPIHBnCFG2 register is clear and multiple chip selects are enabled, then all chip selects are configured by the MODE bit field in the EPIHBnCFG register. Note that multiple chip select modes do not allow the intermixing of Host-Bus 8 and Host-Bus16 modes. When BSEL=1 in the EPIHB16CFG register, byte select signals are provided, so byte-sized data can be read and written at any address, however these signals reduce the available address width by 2 pins. The byte select signals are active Low. BSEL0n corresponds to the LSB of the halfword, and BSEL1n corresponds to the MSB of the halfword. When BSEL=0, byte reads and writes at odd addresses only act on the even byte, and byte writes at even addresses write invalid values into the odd byte. As a result, accesses should be made as half-words (16-bits) or words (32-bits). In C/C++, programmers should use only short int and long int for accesses. Also, because data accesses in HB16 mode with no byte selects are on 2-byte boundaries, the available address space is doubled. For example, 28 bits of address accesses 512 MB in this mode. Table 11-7 on page 829 shows the capabilities of the HB8 and HB16 modes as well as the available address bits with the possible combinations of these bits. Although the EPI0S31 signal can be configured for the EPI clock signal in Host-Bus mode, it is not required and should be configured as a GPIO to reduce EMI in the system. Table 11-7. Capabilities of Host Bus 8 and Host Bus 16 Modes Host Bus Type MODE CSCFGEXT CSCFG Max # of External Devices BSEL Byte Access Available Address Addressable Memory HB8 0x0 0 0x0, 0x1 1 N/A Always 28 bits 256 MB HB8 0x0 0 0x2 2 N/A Always 27 bits 128 MB HB8 0x0 0 0x3 2 N/A Always 26 bits 64 MB HB8 0x0 1 0x0 1 N/A Always 27 bits 128 MB HB8 0x0 1 0x1 4 N/A Always 27 bits 128 MB HB8 0x0 1 0x2 4 N/A Always 26 bits 64 MB HB8 0x1 0 0x0, 0x1 1 N/A Always 20 bits 1 MB HB8 0x1 0 0x2 2 N/A Always 19 bits 512 kB HB8 0x1 0 0x3 2 N/A Always 18 bits 256 kB HB8 0x1 1 0x0 1 N/A Always 19 bits 512 kB HB8 0x1 1 0x1 4 N/A Always 19 bits 512 MB HB8 0x1 1 0x2 4 N/A Always 18 bits 256 kB HB8 0x2 0 0x1 1 N/A Always 20 bits 1 MB HB8 0x3 0 0x1 1 N/A Always none - HB8 0x3 0 0x3 2 N/A Always none - HB8 0x3 1 0x0 1 N/A Always none - HB8 0x3 1 0x1 4 N/A Always none - June 18, 2014 829 Texas Instruments-Production Data External Peripheral Interface (EPI) Table 11-7. Capabilities of Host Bus 8 and Host Bus 16 Modes (continued) Host Bus Type MODE CSCFGEXT CSCFG Max # of External Devices BSEL Byte Access Available Address HB8 0x3 1 0x2 4 N/A Always none HB16 0x0 0 0x0, 0x1 1 0 No 28 bits HB16 0x0 0 0x0, 0x1 1 1 Yes 26 bits a 512 MB b 128 MB a 256 MB b 64 MB a 128 MB HB16 0x0 0 0x2 2 0 No 27 bits HB16 0x0 0 0x2 2 1 Yes 25 bits HB16 0x0 0 0x3 2 0 No 26 bits b 32 MB a 256 MB b 128 MB a 256 MB b 64 MB a 128 MB b 32 MB a 8 kB b 2 kB a 4 kB HB16 0x0 0 0x3 2 1 Yes 24 bits HB16 0x0 1 0x0 1 0 No 27 bits HB16 0x0 1 0x0 1 1 Yes 25 bits HB16 0x0 1 0x1 4 0 No 27 bits HB16 0x0 1 0x1 4 1 Yes 25 bits HB16 HB16 0x0 0x0 1 1 0x2 0x2 4 4 0 1 No Yes 26 bits 24 bits HB16 0x1 0 0x0, 0x1 1 0 No 12 bits HB16 0x1 0 0x0, 0x1 1 1 Yes 10 bits HB16 0x1 0 0x2 2 0 Addressable Memory No 11 bits b HB16 0x1 0 0x2 2 1 Yes 9 bits HB16 0x1 0 0x3 2 0 No 10 bits HB16 0x1 0 0x3 2 1 Yes 8 bits a b a 1 kB 2 kB 512 B HB16 0x1 1 0x0 1 0 No 11 bits 4 kB HB16 0x1 1 0x0 1 1 Yes 9 bits b 1 kB HB16 0x1 1 0x1 4 0 a No 11 bits b 4 kB HB16 0x1 1 0x1 4 1 Yes 9 bits HB16 0x1 1 0x2 4 0 No 10 bits HB16 0x1 1 0x2 4 1 Yes 8 bits 512 B HB16 0x3 0 0x1 1 0 No none - HB16 0x3 0 0x1 1 1 Yes none - HB16 0x3 0 0x3 2 0 No none - HB16 0x3 0 0x3 2 1 Yes none - HB16 0x3 1 0x0 1 0 No none - HB16 0x3 1 0x0 1 1 Yes none - HB16 0x3 1 0x1 4 0 No none - HB16 0x3 1 0x1 4 1 Yes none - HB16 0x3 1 0x2 4 0 No none - HB16 0x3 1 0x2 4 1 Yes none - a b 1 kB 2 kB a. If byte selects are not used, data accesses are on 2-byte boundaries. As a result, the available address space is doubled. b. Two EPI signals are used for byte selects, reducing the available address space by two bits. Table 11-8 on page 831 shows how the EPI[31:0] signals function while in Host-Bus 8 mode. Notice that the signal configuration changes based on the address/data mode selected by the MODE 830 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller field in the EPIHB8CFGn register and on the chip select configuration selected by the CSCFG and CSCFGEXT field in the EPIHB8CFG2 register. Although the EPI0S31 signal can be configured for the EPI clock signal in Host-Bus mode, it is not required and should be configured as a GPIO to reduce EMI in the system. Any unused EPI controller signals can be used as GPIOs or another alternate function. Table 11-8. EPI Host-Bus 8 Signal Connections EPI Signal CSCFG HB8 Signal (MODE =ADMUX) HB8 Signal (MODE =ADNOMUX (Cont. Read)) HB8 Signal (MODE =XFIFO) EPI0S0 X a AD0 D0 D0 EPI0S1 X AD1 D1 D1 EPI0S2 X AD2 D2 D2 EPI0S3 X AD3 D3 D3 EPI0S4 X AD4 D4 D4 EPI0S5 X AD5 D5 D5 EPI0S6 X AD6 D6 D6 EPI0S7 X AD7 D7 D7 EPI0S8 X A8 A0 - EPI0S9 X A9 A1 - EPI0S10 X A10 A2 - EPI0S11 X A11 A3 - EPI0S12 X A12 A4 - EPI0S13 X A13 A5 - EPI0S14 X A14 A6 - EPI0S15 X A15 A7 - EPI0S16 X A16 A8 - EPI0S17 X A17 A9 - EPI0S18 X A18 A10 - EPI0S19 X A19 A11 - EPI0S20 X A20 A12 - EPI0S21 X A21 A13 - EPI0S22 X A22 A14 - EPI0S23 X A23 A15 - EPI0S24 X A24 A16 - 0x0 - 0x1 0x2 EPI0S25 0x3 CS1n b A25 A17 - 0x4 - 0x5 - 0x6 - June 18, 2014 831 Texas Instruments-Production Data External Peripheral Interface (EPI) Table 11-8. EPI Host-Bus 8 Signal Connections (continued) EPI Signal CSCFG HB8 Signal (MODE =ADMUX) HB8 Signal (MODE =ADNOMUX (Cont. Read)) A26 A18 CS0n CS0n A26 A18 CS0n CS0n A27 A19 CS1n CS1n CS0n CS0n CS1n CS1n HB8 Signal (MODE =XFIFO) 0x0 0x1 0x2 EPI0S26 0x3 0x4 0x5 0x6 0x0 0x1 0x2 EPI0S27 0x3 0x4 0x5 0x6 FEMPTY FFULL EPI0S28 X RDn/OEn RDn/OEn RDn EPI0S29 X WRn WRn WRn EPI0S30 0x0 ALE ALE - 0x1 CSn CSn CSn 0x2 CS0n CS0n CS0n ALE ALE 0x5 CS0n CS0n - 0x6 ALE ALE - 0x3 0x4 c - c c EPI0S31 X Clock Clock Clock EPI0S32 X iRDY iRDY iRDY 0x0 X X X 0x1 X X X 0x2 X X X 0x3 X X X 0x4 X X X CS3n CS3n 0x0 X X X 0x1 X X X 0x2 X X X 0x3 X X X 0x4 X X X CS2n CS2n EPI0S33 0x5 0x6 EPI0S34 0x5 0x6 832 X X X X June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 11-8. EPI Host-Bus 8 Signal Connections (continued) EPI Signal EPI0S35 CSCFG HB8 Signal (MODE =ADMUX) 0x0 X X X 0x1 X X X 0x2 X X X 0x3 X X X 0x4 X X X CRE CRE 0x5 0x6 HB8 Signal (MODE =ADNOMUX (Cont. Read)) HB8 Signal (MODE =XFIFO) X X a. "X" indicates the state of this field is a don't care. b. When an entry straddles several row, the signal configuration is the same for all rows. c. The clock signal is not required for this mode. Table 11-9 on page 833 shows how the EPI[31:0] signals function while in Host-Bus 16 mode. Notice that the signal configuration changes based on the address/data mode selected by the MODE field in the EPIHB16CFGn register, on the chip select configuration selected by the CSCFG and CSCFGEXT field in the same register, and on whether byte selects are used as configured by the BSEL bit in the EPIHB16CFG register. Although the EPI0S31 signal can be configured for the EPI clock signal in Host-Bus mode, it is not required and should be configured as a GPIO to reduce EMI in the system. Any unused EPI controller signals can be used as GPIOs or another alternate function. Table 11-9. EPI Host-Bus 16 Signal Connections EPI Signal CSCFG EPI0S0 X a BSEL HB16 Signal (MODE =ADMUX) X AD0 b HB16 Signal (MODE =ADNOMUX (Cont. Read)) HB16 Signal (MODE =XFIFO) D0 D0 EPI0S1 X X AD1 D1 D1 EPI0S2 X X AD2 D2 D2 EPI0S3 X X AD3 D3 D3 EPI0S4 X X AD4 D4 D4 EPI0S5 X X AD5 D5 D5 EPI0S6 X X AD6 D6 D6 EPI0S7 X X AD7 D7 D7 EPI0S8 X X AD8 D8 D8 EPI0S9 X X AD9 D9 D9 EPI0S10 X X AD10 D10 D10 EPI0S11 X X AD11 D11 D11 EPI0S12 X X AD12 D12 D12 EPI0S13 X X AD13 D13 D13 EPI0S14 X X AD14 D14 D14 EPI0S15 X X AD15 D15 D15 b EPI0S16 X X A16 A0 - EPI0S17 X X A17 A1 - June 18, 2014 833 Texas Instruments-Production Data External Peripheral Interface (EPI) Table 11-9. EPI Host-Bus 16 Signal Connections (continued) EPI Signal CSCFG BSEL HB16 Signal (MODE =ADMUX) HB16 Signal (MODE =ADNOMUX (Cont. Read)) HB16 Signal (MODE =XFIFO) EPI0S18 X X A18 A2 - EPI0S19 X X A19 A3 - EPI0S20 X X A20 A4 - EPI0S21 X X A21 A5 - EPI0S22 X X A22 A6 - EPI0S23 X c 0 A23 A7 - A24 A8 BSEL0n BSEL0n 0x0 0x1 0x2 EPI0S24 0x3 0x4 0x5 0x6 0x0 0x1 0x2 0x3 EPI0S25 0x4 0x5 0x6 1 0 1 0 1 0 - 1 0 1 0 - 1 0 A24 A8 1 BSEL0n BSEL0n X A25 A9 1 0 0 A25 A9 1 BSEL0n BSEL0n 0 A25 A9 1 BSEL1n BSEL1n 0 A25 A9 1 BSEL0n BSEL0n 0 A25 A9 1 BSEL0n BSEL0n 0 A25 A9 1 BSEL1n BSEL1n 834 - - - CS1n -- - - - June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 11-9. EPI Host-Bus 16 Signal Connections (continued) EPI Signal CSCFG 0x0 0x1 0x2 EPI0S26 0x3 0x4 EPI0S31 A26 A10 1 BSEL0n BSEL0n 0 A26 A10 1 BSEL0n BSEL0n 0 A26 A10 1 BSEL1n BSEL1n X CS0n CS0n 0 A26 A10 1 BSEL1n BSEL1n FEMPTY - A26 A10 BSEL1n CS0n CS0n 0 A27 A11 1 BSEL1n BSEL1n 0 A27 A11 1 BSEL1n BSEL1n 0x2 X CS1n CS1n 0x3 X CS1n CS1n 0x4 X CS0n CS0n - 0x5 X CS1n CS1n - 0x6 X CS1n CS1n - X X RDn/OEn RDn/OEn RDn 0x1 EPI0S30 0 HB16 Signal (MODE =XFIFO) BSEL1n 0x0 EPI0S29 HB16 Signal (MODE =ADNOMUX (Cont. Read)) 1 0x6 EPI0S28 HB16 Signal (MODE =ADMUX) 0 0x5 EPI0S27 BSEL 0 1 - - FFULL X X WRn WRn WRn 0x0 X ALE ALE - 0x1 X CSn CSn CSn 0x2 X CS0n CS0n CS0n 0x3 X ALE ALE - 0x4 X ALE ALE - 0x5 X CS0n CS0n - 0x6 X ALE X X Clock ALE d d d Clock Clock EPI0S32 X X iRDY iRDY iRDY EPI0S33 X X CS3n CS3n X EPI0S34 X X CS2n CS2n X EPI0S35 X X CRE CRE X a. "X" indicates the state of this field is a don't care. b. In this mode, half-word accesses are used. A0 is the LSB of the address and is equivalent to the internal Cortex-M3 A1 address. This pin should be connected to A0 of 16-bit memories. c. When an entry straddles several row, the signal configuration is the same for all rows. d. The clock signal is not required for this mode. June 18, 2014 835 Texas Instruments-Production Data External Peripheral Interface (EPI) The RDYEN in the EPIHBnCFG enables the monitoring of the external iRDY pin to stall accesses. On the rising edge of EPI clock, if iRDY is low, access is stalled. The IRDYDLY can program the number of EPI clock cycles in advance to the stall (1,2 or 3) as shown in Figure 11-5 on page 836. This is a conceptual timing diagram of how the iRDY signal works with different IRDYDLY configurations. When enabled, the iRDY stalls the EPI's internal states, while IRDYDLY controls the delay pipeline when this stall takes affect. The iRDY signal can be connected to multiple devices with a pull up resistor as shown in Figure 11-6 on page 836. Note that when multiple PSRAMs are connected to iRDY, the EPIHPnCFG registers must be programmed to the same iRDY signal polarity through the IRDYINV bit. When connected to a PSRAM, iRDY is used to control the address to data latency. Figure 11-5. iRDY Access Stalls, IRDYDLY==01, 10, 11 CLOCK (EPI0S31) IRDY (EPI0S32) State Data A Data B IRDYDLY=01 Data A IRDYDLY=10 Data A Data B IRDYDLY=11 Data A Data B Data C Data B Data D Data E Data F Data C Data D Data E Data D Data E Data C Data C Data D Data E Figure 11-6. iRDY Signal Connection Cellular RAM WAIT IRDY Processor 11.4.3.2 WAIT WAIT Other Device Other Device PSRAM Support The EPI Host Bus supports both a synchronous and asynchronous interface to PSRAM memory when configured in 16-bit bus multiplexed mode. The EPIHBPSRAM register holds the values for the PSRAM's bus configuration registers (CR). The contents of the EPIHBPSRAM register can be sent to different memories depending on which WRCRE or RDCRE bit is set in the various EPIHB16CFGn registers. For example, if the WRCRE bit is enabled in EPIHB16CFG, then the CRE signal asserts and the contents are sent to the memory enabled by CS0. Enabling the WRCRE or RDCRE bit in EPIHB16CFG2 register activates CS1n during a PSRAM configuration register write or read. The WRCRE and RDCRE bit in EBIHB16CFG3 corresponds to CS2n and EPIHB16CFG4, to CS3n. The WRCRE bit clears when the transfer is done. There must not be any system access or 836 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller non-blocking read activity during the CRE read or write-enable transfer. During a write to the PSRAM's CR, the configuration data is written out on data pins [20:0] of the EPI bus. For a PSRAM configuration read access, the RDCRE bit in the EPIHB16CFG register is set to signal that the next access is a read of the PSRAM configuration register (CR). The address for the CR is written to bits CR[19:18] of the EPIHBPSRAM register. The read data is returned at CR bits [15:0] of the EPIHBPSRAM register. Note: ■ CRE read and write operations may only occur in asynchronous mode. During synchronous mode the CRE bit should be disabled. Setting the CRE bit during synchronous PSRAM accesses can lead to unpredictable behavior. ■ When the chip select is programmed to access the PSRAM, the MODE bit of the EPIHBnCFGn register must be programmed to enable address and data muxed (ADMUX). Page mode accesses are not supported by the EPI. ■ BURST is optimized for word-length bursting for SDRAM and PSRAM accesses. The subsequent list identifies the steps for initializing the PSRAM interface: 1. Follow the EPI initialization steps in “Initialization and Configuration” on page 821. 2. Enable Host Bus 16 Mode by setting the MODE bits in the EPICFG register to 0x13. Choose between an integer or formula clock divide for the baud rate by configuring the INTDIV bit in the EPICFG register. 3. Configure the EPIBAUD register to the desired baud rate. 4. Since the EPI module only supports asynchronous programming of the configuration registers, clock gate the EPI clock by programming both the CLKGATE and CLKGATEI bits in the EPIHB16CFG register to 0. 5. Prepare for writing the PSRAM's Bus Configuration Register by setting the ALEHIGH = 1 and MODE=0x0 in the EPIHB16CFG register. 6. Program the EPIHBPSRAM register to be loaded into the CR register of the PSRAM by configuring bits [21:0]. ■ CR[20:19] =0x0, reserved ■ CR[19:18] = 0x2 to enable configuring of the CR register ■ CR[15]= 0x1 to enable asynchronous access ■ CR [14] = 0 if the iRDY signal is used for memory transfers; if the design will not use the iRDY signal CR[14] should be cleared. ■ CR[13:11] must be programmed to have a matching read and write wait state configuration as is programmed in the EPIHB16CFG and EPIHB16TIME register. ■ CR[10] configures the polarity of the WAIT signal and should match the configuration of the IRDYINV bit in the EPIHB16CFG register. ■ CR[8]=0x1 to configure the appropriate wait configuration of the data ■ CR[2:0]=0x7 since the EPI interface in PSRAM mode is a continuous burst access. June 18, 2014 837 Texas Instruments-Production Data External Peripheral Interface (EPI) 7. Set the WRCRE bit in the EPIHB16CFGn register to initiate a write from the EPIHBPSRAM register to PSRAM's CR register. Note: If the PSRAM's CR register must be reprogrammed after initialization, the application should allow the previous transfer to complete before beginning configuration to ensure proper PSRAM functionality. Table 11-10. PSRAM Fixed Latency Wait State Configuration Latency Counter Latency in Clocks RDWS[1:0]/WRWS[1:0] RWSM/WRWSM BCR Code 2 3 0x0 0 BCR Code 3 4 0x1 1 BCR Code 4 5 0x1 0 BCR Code 5 6 0x2 1 BCR Code 6 7 0x2 0 BCR Code 8 9 0x3 0 In variable initial latency mode, the memory's WAIT (iRDY) pin guides the EPI module when to read and write. The WAIT (iRDY) pin stalls the access for the duration of the latency and adds cycles if there is a refresh collision. To get the best performance, set CR[13:11] = 0x2, the WRWS field of the EPIHB16CFG register to 0x0, and the WRWSM and RDWSM bit of the EPI16TIMEn register to 0. For the WAIT pin to be recognized correctly set the IRDYDLY bit in the EPI16TIMEn register to 1 and the CR[8] =1 in the EPIHBPSRAM register. Note: Wait state latency works differently in PSRAM Burst mode than in other modes. In PSRAM Burst mode the RDWS and WRWS bit fields define the latency for only the first access of the write or read cycle. Every access after that is a single access. Figure 11-7 on page 839 and Figure 11-8 on page 839 depict a PSRAM burst read and write. 838 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 11-7. PSRAM Burst Read EPICLK EPI0S31 EPI0S[19:0] ADDRESS ALE Latency (3 clocks) CSn RDn WRn EPI0S29 iRDY EPI0S32 EPI0S[15:0] DATA0 DATA1 DATA2 DATA3 BSELn Figure 11-8. PSRAM Burst Write EPICLK EPI0S31 EPI0S[19:0] ALE ADDRESS Latency (3 clocks) CSn OEn EPI0S28 WRn EPI0S29 iRDY EPI0S32 EPI0S[15:0] DATA0 DATA1 DATA2 DATA3 BSELn June 18, 2014 839 Texas Instruments-Production Data External Peripheral Interface (EPI) Note that if a read or write transfer attempts to begin during a refresh event, the transfer is held off by the assertion of the iRDY pin by the memory to the EPI module. Figure 11-9 on page 840 and Figure 11-10 on page 841 depict the delay in data transfer during a refresh collision. Figure 11-9. Read Delay During Refresh Event EPICLK EPI0S31 EPI0S[19:0] ADDRESS ALE CSn OEn EPI0S28 WRn EPI0S29 BSELn iRDY EPI0S32 EPI0S[15:0] DATA0 DATA1 DATA2 DATA3 One wait state 840 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 11-10. Write Delay During Refresh Event EPICLK EPI0S31 EPI0S[19:0] ADDRESS ALE CSn OEn EPI0S28 WRn EPI0S29 BSELn iRDY EPI0S32 EPI0S[15:0] DATA0 DATA1 DATA2 DATA3 One wait state 11.4.3.3 Host Bus 16-bit Muxed Interface Figure 11-11 on page 842 shows how to connect the EPI signals to a 16-bit SRAM and a 16-bit Flash memory with muxed address and memory using byte selects and dual chip selects with ALE. This schematic is just an example of how to connect the signals; timing and loading have not been analyzed. In addition, not all bypass capacitors are shown. June 18, 2014 841 Texas Instruments-Production Data External Peripheral Interface (EPI) Figure 11-11. Example Schematic for Muxed Host-Bus 16 Mode EPI_16_BUS A[0:15] U1 EPI0 EPI1 EPI2 EPI3 EPI4 EPI5 EPI6 EPI7 47 46 44 43 41 40 38 37 EPI8 EPI9 EPI10 EPI11 EPI12 EPI13 EPI14 EPI15 36 35 33 32 30 29 27 26 EPI30 25 2LE 48 1LE 1D1 1D2 1D3 1D4 1D5 1D6 1D7 1D8 1Q1 1Q2 1Q3 1Q4 1Q5 1Q6 1Q7 1Q8 2D1 2D2 2D3 2D4 2D5 2D6 2D7 2D8 2Q1 2Q2 2Q3 2Q4 2Q5 2Q6 2Q7 2Q8 1 1OE 24 2OE +3.3V 7 VCC 18 VCC 31 VCC 42 VCC GND GND GND GND GND GND GND GND GND 2 3 5 6 8 9 11 12 A0 A1 A2 A3 A4 A5 A6 A7 13 14 16 17 19 20 22 23 A8 A9 A10 A11 A12 A13 A14 A15 4 10 15 21 28 34 39 45 GND 74X16373 EPI_16_BUS EPI_16_BUS EPI_16_BUS EPI_16_BUS A[0:15] A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 EPI16 EPI17 U2 5 4 3 2 1 44 43 42 27 26 25 24 23 22 21 20 19 18 A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 I/O0 I/O1 I/O2 I/O3 I/O4 I/O5 I/O6 I/O7 I/O8 I/O9 I/O10 I/O11 I/O12 I/O13 I/O14 I/O15 NC +3.3V 11 VCC 33 VCC GND EPI0 EPI1 EPI2 EPI3 EPI4 EPI5 EPI6 EPI7 EPI8 EPI9 EPI10 EPI11 EPI12 EPI13 EPI14 EPI15 EPI16 EPI17 EPI18 28 17 EPI29 6 EPI26 41 EPI28 40 BHE 39 BLE EPI25 EPI24 WE CE OE 12 VSS 34 VSS 7 8 9 10 13 14 15 16 29 30 31 32 35 36 37 38 A[0:15] A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 CY62147 U3 25 24 23 22 21 20 19 18 8 7 6 5 4 3 2 1 48 17 16 9 10 12 13 14 15 47 A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 NC NC NC NC NC NC NC 29 31 33 35 38 40 42 44 30 32 34 36 39 41 43 45 EPI0 EPI1 EPI2 EPI3 EPI4 EPI5 EPI6 EPI7 EPI8 EPI9 EPI10 EPI11 EPI12 EPI13 EPI14 EPI15 11 WE 28 OE 26 CE EPI29 EPI28 EPI27 DQ0 DQ1 DQ2 DQ3 DQ4 DQ5 DQ6 DQ7 DQ8 DQ9 DQ10 DQ11 DQ12 DQ13 DQ14 DQ15 +3.3V VDD 46 VSS 27 VSS SST39VF800A 11.4.3.4 37 GND Speed of Transactions The COUNT0 field in the EPIBAUD register must be configured to set the main transaction rate based on what the slave device can support (including wiring considerations). The main control transitions are normally ½ the baud rate (COUNT0 = 1) because the EPI block forces data versus control to change on alternating clocks. When using dual chip selects, each chip select can access the bus using differing baud rates by setting the CSBAUD bit in the EPIHBnCFG2 register. In this case, the COUNT0 field controls the CS0n transactions, and the COUNT1 field controls the CS1n transactions. When using quad chip select mode, the COUNT0 bit field of the EPIBAUD2 register 842 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller controls the baud rate of CS2n and the COUNT1 bit field is programmed to control the baud rate of CS3n. Additionally, the Host-Bus mode provides read and write wait states for the data portion to support different classes of device. These wait states stretch the data period (hold the rising edge of data strobe) and may be used in all four sub-modes. The wait states are set using the WRWS and RDWS bits in the EPI Host-Bus n Configuration (EPIHBnCFGn) register. The WRWS and RDWS bits are enhanced with more precision by WRWSM and RDWSM bits in the EPIHBnTIMEn registers. Note none of the wait state configuration bits can be set concurrently with the BURST bit in the same EPIHBnCFGn register. See Table 11-11 on page 843 for programming information. Table 11-11. Data Phase Wait State Programming RDWS or WRWS Encoding in EPIHBnCFGn Register RDWSM or WRWSM Encoding in EPIHBnTIMEn Registers Data Phase Wait States 0x0 1 1 EPI clocks 0x0 0 2 EPI clocks 0x1 1 3 EPI clocks 0x1 0 4 EPI clocks 0x2 1 5 EPI clocks 0x2 0 6 EPI clocks 0x3 1 7 EPI clocks 0x3 0 8 EPI clocks The CAPWIDTH bit in EPIHBnTIMEn registers controls the delay between Host-Bus transfers. When the CSBAUD bit is set and multi-chip selects have been configured in the EPIHBnCFG2 registers, delay takes an additional clock cycle to adjust the clock rate of different chip selects. Word read and write transactions can be enhanced through the enabling of the BURST bit in the EPIHB16CFGn registers. 11.4.3.5 Sub-Modes of Host Bus 8/16 The EPI controller supports four variants of the Host-Bus model using 8 or 16 bits of data in all four cases. The four sub-modes are selected using the MODE bits in the EPIHBnCFG register, and are: 1. Address and data are muxed. This scheme is used by many 8051 devices, some Microchip PIC parts, and some ATmega parts. When used for standard SRAMs, a latch must be used between the microcontroller and the SRAM. This sub-mode is provided for compatibility with existing devices that support data transfers without a latch (that is, CPLDs). In general, the de-muxed sub-mode should normally be used. The ALE configuration should be used in this mode, as all Host-Bus accesses have an address phase followed by a data phase. The ALE indicates to an external latch to capture the address then hold until the data phase. The ALE configuration is controlled by configuring the CSCFG and CSCFGEXT field to be 0x0 in the EPIHBnCFG2 register. The ALE can be enhanced to access two or four external devices with four separate CSn signals. By configuring the CSCFG field to be 0x3 and the CSCFGEXT bit to be 0 in the EPIHBnCFG2 register, EPI0S30 functions as ALE, EPI0S27 functions as CS1n, and EPI0S26 functions as CS0n. When the CSCFG field is set to 0x0 and the CSCFGEXT bit is set to 1 in the EPIHBnCFG2 register, EPI0S30 functions as ALE, EPIOS33 functions as CS3n, EPIOS34 functions as CS2n, EPI0S27 functions as CS1n, and EPI0S26 functions as CS0n. The CSn is best used for Host-Bus unmuxed mode, in which EPI address and data pins are separate. The CSn indicates when the address and data phases of a read or write access are occurring. June 18, 2014 843 Texas Instruments-Production Data External Peripheral Interface (EPI) 2. Address and data are separate with 8 or 16 bits of data and up to 20 bits of address (1 MB). This scheme is used by more modern 8051 devices, as well as some PIC and ATmega parts. This mode is generally used with SRAMs in continuous read modes, many EEPROMs, and many NOR Flash memory devices. Note that there is no hardware command write support for Flash memory devices; this mode should only be used for Flash memory devices programmed at manufacturing time. If a Flash memory device must be written and does not support a direct programming model, the command mechanism must be performed in software. The CSn configuration should be used in this mode. The CSn signal indicates when the address and data phases of a read or write access is occurring. The CSn configuration is controlled by configuring the CSCFG field to be 0x1 and the CSCFGEXT bit to be 0 in the EPIHBnCFG2 register. 3. Continuous read mode where address and data are separate. This read sub-mode is used by some SRAMs and can read more quickly by only changing the address (and not using RDn/OEn strobing). In this sub-mode, reads are performed by keeping the read mode selected (output enable is asserted) and then changing the address pins. The data pins are changed by the SRAM after the address pins change. For example, to read data from address 0x100 and then 0x101, the EPI controller asserts the output-enable signal and then configures the address pins to 0x100; the EPI controller then captures what is on the data pins and increments A0 to 1 (so the address is now 0x101); the EPI controller then captures what is on the data pins. Note that this mode consumes higher power because the SRAM must continuously drive the data pins. This mode is not practical in HB16 mode for normal SRAMs because there are generally not enough address bits available. Writes are not permitted in this mode. 4. FIFO mode uses 8 or 16 bits of data, removes ALE and address pins and optionally adds external XFIFO FULL/EMPTY flag inputs. This scheme is used by many devices, such as radios, communication devices (including USB2 devices), and some FPGA configurations (FIFO through block RAM). This sub-mode provides the data side of the normal Host-Bus interface, but is paced by the FIFO control signals. It is important to consider that the XFIFO FULL/EMPTY control signals may stall the interface and could have an impact on blocking read latency from the processor or μDMA. Note that the EPI FIFO can only be used in asynchronous mode. For the three modes above (1, 2, 4) that the Host-Bus 16 mode supports, byte select signals can be optionally implemented by setting the BSEL bit in the EPIHB16CFG register. Note: Byte accesses should not be attempted if the BSEL bit has not been enabled in Host-Bus 16 Mode. See “External Peripheral Interface (EPI)” on page 1853 for timing details for the Host-Bus mode. 11.4.3.6 Bus Operation Bus operation is the same in Host-Bus 8 and Host-Bus 16 modes and is asynchronous. Timing diagrams show both ALE and CSn operation. The optional HB16 byte select signals have the same timing as the address signals. If wait states are required in the bus access, they can be inserted during the data phase of the access using the WRWS and RDWS bits in the EPIHBnCFG2 register. Each wait state adds 2 EPI clock cycles to the duration of the WRn or RDn strobe. During idle cycles, the address and muxed address data signals maintain the state of the last cycle. Figure 11-12 on page 845 shows a basic Host-Bus read cycle. Figure 11-13 on page 845 shows a basic Host-Bus write cycle. Both of these figures show address and data signals in the non-multiplexed mode (MODE field ix 0x1 in the EPIHBnCFG register). 844 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 11-12. Host-Bus Read Cycle, MODE = 0x1, WRHIGH = 0, RDHIGH = 0 ALE (EPI0S30) CSn (EPI0S30) WRn (EPI0S29) RDn/OEn (EPI0S28) BSEL0n/ BSEL1na Address Data a Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. Figure 11-13. Host-Bus Write Cycle, MODE = 0x1, WRHIGH = 0, RDHIGH = 0 ALE (EPI0S30) CSn (EPI0S30) WRn (EPI0S29) RDn/OEn (EPI0S28) BSEL0n/ BSEL1na Address Data a Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. Figure 11-14 on page 846 shows a write cycle with the address and data signals multiplexed (MODE field is 0x0 in the EPIHBnCFG register). A read cycle would look similar, with the RDn strobe being asserted along with CSn and data being latched on the rising edge of RDn. June 18, 2014 845 Texas Instruments-Production Data External Peripheral Interface (EPI) Figure 11-14. Host-Bus Write Cycle with Multiplexed Address and Data, MODE = 0x0, WRHIGH = 0, RDHIGH = 0 ALE (EPI0S30) CSn (EPI0S30) WRn (EPI0S29) RDn/OEn (EPI0S28) BSEL0n/ BSEL1na Address (high order, non muxed) Muxed Address/Data a Address Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. When using ALE with dual CSn configuration (CSCFGEXT bit is 0 and the CSCFG field is 0x3 in the EPIHBnCFG2 register) or quad chip select (CSCFGEXT bit is 1 and CSCSFG is 0x2), the appropriate CSn signal is asserted at the same time as ALE, as shown in Figure 11-15 on page 846. Figure 11-15. Host-Bus Write Cycle with Multiplexed Address and Data and ALE with Dual or Quad CSn ALE (EPI0S30) CS0n/CS1n/CS2n/CS3n (EPI0S26/EPI0S27/ EPIOS34/EPIOS33) WRn (EPI0S29) RDn/OEn (EPI0S28) BSEL0n/ BSEL1na Address (high order, non muxed) Muxed Address/Data a Address Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. Figure 11-16 on page 846 shows continuous read mode accesses. In this mode, reads are performed by keeping the read mode selected (output enable is asserted) and then changing the address pins. The data pins are changed by the SRAM after the address pins change. Figure 11-16. Continuous Read Mode Accesses OEn Address Data Addr1 Data1 Addr2 Data2 846 Addr3 Data3 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller FIFO mode accesses are the same as normal read and write accesses, except that the ALE signal and address pins are not present. Two input signals can be used to indicate when the XFIFO is full or empty to gate transactions and avoid overruns and underruns. The FFULL and FEMPTY signals are synchronized and must be recognized as asserted by the microcontroller for 2 system clocks before they affect transaction status. The MAXWAIT field in the EPIHBnCFG register defines the maximum number of EPI clocks to wait while the FEMPTY or FFULL signal is holding off a transaction. Figure 11-17 on page 847 shows how the FEMPTY signal should respond to a write and read from the XFIFO. Figure 11-18 on page 847 shows how the FEMPTY and FFULL signals should respond to 2 writes and 1 read from an external FIFO that contains two entries. Figure 11-17. Write Followed by Read to External FIFO FFULL (EPI0S27) FEMPTY (EPI0S26) CSn (EPI0S30) WRn (EPI0S29) RDn (EPI0S28) Data Data Data Figure 11-18. Two-Entry FIFO FFULL (EPI0S27) FEMPTY (EPI0S26) CSn (EPI0S30) WRn (EPI0S29) RDn (EPI0S28) Data 11.4.4 Data Data Data General-Purpose Mode The General-Purpose Mode Configuration (EPIGPCFG) register is used to configure the control, data, and address pins, if used. Any unused EPI controller signals can be used as GPIOs or another alternate function. The general-purpose configuration can be used for custom interfaces with FPGAs, CPLDs, and digital data acquisition and actuator control. General-Purpose mode is designed for three general types of use: ■ Extremely high-speed clocked interfaces to FPGAs and CPLDs. Three sizes of data and optional address are supported. Framing and clock-enable functions permit more optimized interfaces. ■ General parallel GPIO. From 1 to 32 pins may be written or read, with the speed precisely controlled by the EPIBAUD register baud rate (when used with the WFIFO and/or the NBRFIFO) or by the rate of accesses from software or μDMA. Examples of this type of use include: June 18, 2014 847 Texas Instruments-Production Data External Peripheral Interface (EPI) – Reading 20 sensors at fixed time periods by configuring 20 pins to be inputs, configuring the COUNT0 field in the EPIBAUD register to some divider, and then using non-blocking reads. – Implementing a very wide ganged PWM/PCM with fixed frequency for driving actuators, LEDs, etc. ■ General custom interfaces of any speed. The configuration allows for choice of an output clock (free-running or gated), a framing signal (with frame size), a ready input (to stretch transactions), an address (of varying sizes), and data (of varying sizes). Additionally, provisions are made for separating data and address phases. The interface has the following optional features: ■ Use of the EPI clock output is controlled by the CLKPIN bit in the EPIGPCFG register. Unclocked uses include general-purpose I/O and asynchronous interfaces (optionally using RD and WR strobes). Clocked interfaces allow for higher speeds and are much easier to connect to FPGAs and CPLDs (which usually include input clocks). ■ EPI clock, if used, may be free running or gated depending on the CLKGATE bit in the EPIGPCFG register. A free-running EPI clock requires another method for determining when data is live, such as the frame pin or RD/WR strobes. A gated clock approach uses a setup-time model in which the EPI clock controls when transactions are starting and stopping. The gated clock is held high until a new transaction is started and goes high at the end of the cycle where RD/WR/FRAME and address (and data if write) are emitted. ■ Use of the RD and WR outputs is controlled by the RW bit in the EPIGPCFG register. For interfaces where the direction is known (in advance, related to frame size, or other means), these strobes are not needed. For most other interfaces, RD and WR are used so the external peripheral knows what transaction is taking place, and if any transaction is taking place. ■ Separation of address/request and data phases may be used on writes using the WR2CYC bit in the EPIGPCFG register. This configuration allows the external peripheral extra time to act. Address and data phases must be separated on reads. When configured to use an address as specified by the ASIZE field in the EPIGPCFG register, the address is emitted on the with the RD strobe (first cycle) and data is expected to be returned on the next cycle (when RD is not asserted). If no address is used, then RD is asserted on the first cycle and data is captured on the second cycle (when RD is not asserted), allowing more setup time for data. Note: When WR2CYC = 0, write data is valid when the WR strobe is asserted (High). When WR2CYC = 1, write data is valid when the WR strobe is Low after being asserted (High). For writes, the output may be in one or two cycles. In the two-cycle case, the address (if any) is emitted on the first cycle with the WR strobe and the data is emitted on the second cycle (with WR not asserted). Although split address and write data phases are not normally needed for logic reasons, it may be useful to make read and write timings match. If 2-cycle reads or writes are used, the RW bit is automatically set. ■ Address may be emitted (controlled by the ASIZE field in the EPIGPCFG register). The address may be up to 4 bits (16 possible values), up to 12 bits (4096 possible values), or up to 20 bits (1 M possible values). Size of address limits size of data, for example, 4 bits of address support up to 24 bits data. 4-bit address uses EPI0S[27:24]; 12-bit address uses EPI0S[27:16]; 20-bit address uses EPI0S[27:8]. The address signals may be used by the external peripheral as an address, code (command), or for other unrelated uses (such as a chip enable). If the chosen address/data combination does not use all of the EPI signals, the unused pins can be 848 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller used as GPIOs or for other functions. For example, when using a 4-bit address with an 8-bit data, the pins assigned to EPIS0[23:8] can be assigned to other functions. ■ Data may be 8 bits, 16 bits, 24 bits, or 32 bits (controlled by the DSIZE field in the EPIGPCFG register). By default, the EPI controller uses data bits [7:0] when the DSIZE field in the EPIGPCFG register is 0x0; data bits [15:0] when the DSIZE field is 0x1; data bits [23:0] when the DSIZE field is 0x2; and data bits [31:0] when the DSIZE field is 0x3.32-bit data cannot be used with address or EPI clock or any other signal. 24-bit data can only be used with 4-bit address or no address. ■ When using the EPI controller as a GPIO interface, writes are FIFOed (up to 4 can be held at any time), and up to 32 pins are changed using the EPIBAUD clock rate specified by COUNT0. As a result, output pin control can be very precisely controlled as a function of time. By contrast, when writing to normal GPIOs, writes can only occur 8-bits at a time and take up to two clock cycles to complete. In addition, the write itself may be further delayed by the bus due to μDMA or draining of a previous write. With both GPIO and the EPI controller, reads may be performed directly, in which case the current pin states are read back. With the EPI controller, the non-blocking interface may also be used to perform reads based on a fixed time rule via the EPIBAUD clock rate. Table 11-12 on page 849 shows how the EPI0S[31:0] signals function while in General-Purpose mode. Notice that the address connections vary depending on the data-width restrictions of the external peripheral. Table 11-12. EPI General-Purpose Signal Connections EPI Signal General-Purpose Signal (D8, A20) General- Purpose Signal (D16, A12) General- Purpose Signal (D24, A4) General- Purpose Signal (D32) EPI0S0 D0 D0 D0 D0 EPI0S1 D1 D1 D1 D1 EPI0S2 D2 D2 D2 D2 EPI0S3 D3 D3 D3 D3 EPI0S4 D4 D4 D4 D4 EPI0S5 D5 D5 D5 D5 EPI0S6 D6 D6 D6 D6 EPI0S7 D7 D7 D7 D7 EPI0S8 A0 D8 D8 D8 EPI0S9 A1 D9 D9 D9 EPI0S10 A2 D10 D10 D10 EPI0S11 A3 D11 D11 D11 EPI0S12 A4 D12 D12 D12 EPI0S13 A5 D13 D13 D13 EPI0S14 A6 D14 D14 D14 EPI0S15 A7 D15 D15 D15 A8 a A0 D16 D16 EPI0S17 A9 A1 D17 D17 EPI0S18 A10 A2 D18 D18 EPI0S19 A11 A3 D19 D19 EPI0S20 A12 A4 D20 D20 EPI0S16 June 18, 2014 849 Texas Instruments-Production Data External Peripheral Interface (EPI) Table 11-12. EPI General-Purpose Signal Connections (continued) EPI Signal General-Purpose Signal (D8, A20) General- Purpose Signal (D16, A12) General- Purpose Signal (D24, A4) General- Purpose Signal (D32) EPI0S21 A13 A5 D21 D21 EPI0S22 A14 A6 D22 D22 EPI0S23 A15 A7 D23 D23 A8 b A0 D24 EPI0S24 A16 EPI0S25 A17 A9 A1 D25 EPI0S26 A18 A10 A2 D26 EPI0S27 A19 A11 A3 D27 EPI0S28 WR WR WR D28 EPI0S29 RD RD RD D29 EPI0S30 Frame Frame Frame D30 EPI0S31 Clock Clock Clock D31 a. In this mode, half-word accesses are used. AO is the LSB of the address and is equivalent to the system A1 address. b. In this mode, word accesses are used. AO is the LSB of the address and is equivalent to the system A2 address. 11.4.4.1 Bus Operation A basic access is 1 EPI clock for write cycles and 2 EPI clocks for read cycles. An additional EPI clock can be inserted into a write cycle by setting the WR2CYC bit in the EPIGPCFG register. Figure 11-19. Single-Cycle Single Write Access, FRM50=0, FRMCNT=0, WR2CYC=0 Clock (EPI0S31) Frame (EPI0S30) RD (EPI0S29) WR (EPI0S28) Address Data Data 850 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 11-20. Two-Cycle Read, Write Accesses, FRM50=0, FRMCNT=0, WR2CYC=1 CLOCK (EPI0S31) FRAME (EPI0S30) RD (EPI0S29) WR (EPI0S28) Address Data Data Data Read Write Figure 11-21. Read Accesses, FRM50=0, FRMCNT=0 CLOCK (EPI0S31) FRAME (EPI0S30) RD (EPI0S29) WR (EPI0S28) Addr1 Address Addr2 Data1 Data Addr3 Data2 Data3 FRAME Signal Operation The operation of the FRAME signal is controlled by the FRMCNT and FRM50 bits. When FRM50 is clear, the FRAME signal is high whenever the WR or RD strobe is high. When FRMCNT is clear, the FRAME signal is simply the logical OR of the WR and RD strobes so the FRAME signal is high during every read or write access, see Figure 11-22 on page 852. June 18, 2014 851 Texas Instruments-Production Data External Peripheral Interface (EPI) Figure 11-22. FRAME Signal Operation, FRM50=0 and FRMCNT=0 Clock (EPI0S31) WR (EPI0S28) RD (EPI0S29) Frame (EPI0S30) If the FRMCNT field is 0x1, then the FRAME signal pulses high during every other read or write access, see Figure 11-23 on page 852. Figure 11-23. FRAME Signal Operation, FRM50=0 and FRMCNT=1 Clock (EPI0S31) WR (EPI0S28) RD (EPI0S29) Frame (EPI0S30) If the FRMCNT field is 0x2 and FRM50 is clear, then the FRAME signal pulses high during every third access, and so on for every value of FRMCNT, see Figure 11-24 on page 852. Figure 11-24. FRAME Signal Operation, FRM50=0 and FRMCNT=2 Clock (EPI0S31) WR (EPI0S28) RD (EPI0S29) Frame (EPI0S30) When FRM50 is set, the FRAME signal transitions on the rising edge of either the WR or RD strobes. When FRMCNT=0, the FRAME signal transitions on the rising edge of WR or RD for every access, see Figure 11-25 on page 852. Figure 11-25. FRAME Signal Operation, FRM50=1 and FRMCNT=0 Clock (EPI0S31) WR (EPI0S28) RD (EPI0S29) Frame (EPI0S30) When FRMCNT=1, the FRAME signal transitions on the rising edge of the WR or RD strobes for every other access, see Figure 11-26 on page 853. 852 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 11-26. FRAME Signal Operation, FRM50=1 and FRMCNT=1 Clock (EPI0S31) WR (EPI0S28) RD (EPI0S29) Frame (EPI0S30) When FRMCNT=2, the FRAME signal transitions the rising edge of the WR or RD strobes for every third access, and so on for every value of FRMCNT, see Figure 11-27 on page 853. Figure 11-27. FRAME Signal Operation, FRM50=1 and FRMCNT=2 CLOCK (EPI0S31) WR (EPI0S28) RD (EPI0S29) FRAME (EPI0S30) EPI Clock Operation If the CLKGATE bit in the EPIGPCFG register is clear, the EPI clock always toggles when General-purpose mode is enabled. If CLKGATE is set, the clock is output only when a transaction is occurring, otherwise the clock is held high. If the WR2CYC bit is clear, the EPI clock begins toggling 1 cycle before the WR strobe goes High. If the WR2CYC bit is set, the EPI clock begins toggling when the WR strobe goes High. The clock stops toggling after the first rising edge after the WR strobe is deasserted. The RD strobe operates in the same manner as the WR strobe when the WR2CYC bit is set. See Figure 11-28 on page 853 and Figure 11-29 on page 854. Figure 11-28. EPI Clock Operation, CLKGATE=1, WR2CYC=0 Clock (EPI0S31) WR (EPI0S28) Address Data June 18, 2014 853 Texas Instruments-Production Data External Peripheral Interface (EPI) Figure 11-29. EPI Clock Operation, CLKGATE=1, WR2CYC=1 Clock (EPI0S31) WR (EPI0S28) Address Data 11.5 Register Map Table 11-13 on page 854 lists the EPI registers. The offset listed is a hexadecimal increment to the register's address, relative to the base address of 0x400D.0000. Note that the EPI controller clock must be enabled before the registers can be programmed (see page 386). There must be a delay of 3 system clocks after the EPI module clock is enabled before any EPI module registers are accessed. Note: A write immediately followed by a read of the same register, may not return correct data. A delay (instruction or NOP) must be inserted between the write and the read for correct operation. Read-write does not have this issue, so use of read-write for clear of error interrupt cause is not affected. Note: For all versions of EPI, only WORD read and write accesses to registers are supported. Table 11-13. External Peripheral Interface (EPI) Register Map Offset Name 0x000 Description See page Type Reset EPICFG RW 0x0000.0000 EPI Configuration 857 0x004 EPIBAUD RW 0x0000.0000 EPI Main Baud Rate 859 0x008 EPIBAUD2 RW 0x0000.0000 EPI Main Baud Rate 861 0x010 EPISDRAMCFG RW 0x82EE.0000 EPI SDRAM Configuration 863 0x010 EPIHB8CFG RW 0x0008.FF00 EPI Host-Bus 8 Configuration 865 0x010 EPIHB16CFG RW 0x0008.FF00 EPI Host-Bus 16 Configuration 870 0x010 EPIGPCFG RW 0x0000.0000 EPI General-Purpose Configuration 876 0x014 EPIHB8CFG2 RW 0x0008.0000 EPI Host-Bus 8 Configuration 2 879 0x014 EPIHB16CFG2 RW 0x0008.0000 EPI Host-Bus 16 Configuration 2 885 0x01C EPIADDRMAP RW 0x0000.0000 EPI Address Map 892 0x020 EPIRSIZE0 RW 0x0000.0003 EPI Read Size 0 895 0x024 EPIRADDR0 RW 0x0000.0000 EPI Read Address 0 896 0x028 EPIRPSTD0 RW 0x0000.0000 EPI Non-Blocking Read Data 0 897 0x030 EPIRSIZE1 RW 0x0000.0003 EPI Read Size 1 895 854 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 11-13. External Peripheral Interface (EPI) Register Map (continued) Offset Name 0x034 Description See page Type Reset EPIRADDR1 RW 0x0000.0000 EPI Read Address 1 896 0x038 EPIRPSTD1 RW 0x0000.0000 EPI Non-Blocking Read Data 1 897 0x060 EPISTAT RO 0x0000.0000 EPI Status 899 0x06C EPIRFIFOCNT RO - EPI Read FIFO Count 901 0x070 EPIREADFIFO0 RO - EPI Read FIFO 902 0x074 EPIREADFIFO1 RO - EPI Read FIFO Alias 1 902 0x078 EPIREADFIFO2 RO - EPI Read FIFO Alias 2 902 0x07C EPIREADFIFO3 RO - EPI Read FIFO Alias 3 902 0x080 EPIREADFIFO4 RO - EPI Read FIFO Alias 4 902 0x084 EPIREADFIFO5 RO - EPI Read FIFO Alias 5 902 0x088 EPIREADFIFO6 RO - EPI Read FIFO Alias 6 902 0x08C EPIREADFIFO7 RO - EPI Read FIFO Alias 7 902 0x200 EPIFIFOLVL RW 0x0000.0033 EPI FIFO Level Selects 903 0x204 EPIWFIFOCNT RO 0x0000.0004 EPI Write FIFO Count 905 0x208 EPIDMATXCNT RW 0x0000.0000 EPI DMA Transmit Count 906 0x210 EPIIM RW 0x0000.0000 EPI Interrupt Mask 907 0x214 EPIRIS RO 0x0000.0004 EPI Raw Interrupt Status 909 0x218 EPIMIS RO 0x0000.0000 EPI Masked Interrupt Status 911 0x21C EPIEISC RW1C 0x0000.0000 EPI Error and Interrupt Status and Clear 913 0x308 EPIHB8CFG3 RW 0x0008.0000 EPI Host-Bus 8 Configuration 3 915 0x308 EPIHB16CFG3 RW 0x0008.0000 EPI Host-Bus 16 Configuration 3 918 0x30C EPIHB8CFG4 RW 0x0008.0000 EPI Host-Bus 8 Configuration 4 922 0x30C EPIHB16CFG4 RW 0x0008.0000 EPI Host-Bus 16 Configuration 4 925 0x310 EPIHB8TIME RW 0x0002.2000 EPI Host-Bus 8 Timing Extension 929 0x310 EPIHB16TIME RW 0x0002.2000 EPI Host-Bus 16 Timing Extension 931 0x314 EPIHB8TIME2 RW 0x0002.2000 EPI Host-Bus 8 Timing Extension 933 0x314 EPIHB16TIME2 RW 0x0002.2000 EPI Host-Bus 16 Timing Extension 935 0x318 EPIHB8TIME3 RW 0x0002.2000 EPI Host-Bus 8 Timing Extension 937 0x318 EPIHB16TIME3 RW 0x0002.2000 EPI Host-Bus 16 Timing Extension 939 0x31C EPIHB8TIME4 RW 0x0002.2000 EPI Host-Bus 8 Timing Extension 941 0x31C EPIHB16TIME4 RW 0x0002.2000 EPI Host-Bus 16 Timing Extension 943 0x360 EPIHBPSRAM RW 0x0000.0000 EPI Host-Bus PSRAM 945 June 18, 2014 855 Texas Instruments-Production Data External Peripheral Interface (EPI) 11.6 Register Descriptions This section lists and describes the EPI registers, in numerical order by address offset. 856 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: EPI Configuration (EPICFG), offset 0x000 Important: The MODE field determines which configuration register is accessed for offsets 0x010 and 0x014. Any write to the EPICFG register resets the register contents at offsets 0x010 and 0x014. The configuration register is used to enable the block, select a mode, and select the basic pin use (based on the mode). Note that attempting to program an undefined MODE field clears the BLKEN bit and disables the EPI controller. EPI Configuration (EPICFG) Base 0x400D.0000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 INTDIV Bit/Field Name Type Reset 31:9 reserved RO 0x0000.00 8 INTDIV RW 0 RW 0 reserved RO 0 RO 0 BLKEN RO 0 RW 0 MODE Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Integer Clock Divider Enable Value Description 7:5 reserved RO 0x0 4 BLKEN RW 0 0 EPIBAUD register values create formula clock divide. 1 EPIBAUD register values create integer clock divide. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Block Enable Value Description 0 The EPI controller is disabled. 1 The EPI controller is enabled. June 18, 2014 857 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 3:0 MODE RW 0x0 Mode Select Value Description 0x0 General Purpose General-Purpose mode. Control, address, and data pins are configured using the EPIGPCFG and EPIGPCFG2 registers. 0x1 SDRAM Supports SDR SDRAM. Control, address, and data pins are configured using the EPISDRAMCFG register. 0x2 8-Bit Host-Bus (HB8) Host-bus 8-bit interface (also known as the MCU interface). Control, address, and data pins are configured using the EPIHB8CFG and EPIHB8CFG2 registers. 0x3 16-Bit Host-Bus (HB16) Host-bus 16-bit interface (standard SRAM). Control, address, and data pins are configured using the EPIHB16CFG and EPIHB16CFG2 registers. 0x3-0xF Reserved 858 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: EPI Main Baud Rate (EPIBAUD), offset 0x004 The system clock is used internally to the EPI Controller. The baud rate counter can be used to divide the system clock down to control the speed on the external interface. If the mode selected emits an external EPI clock, this register defines the EPI clock emitted. If the mode selected does not use an EPI clock, this register controls the speed of changes on the external interface. Care must be taken to program this register properly so that the speed of the external bus corresponds to the speed of the external peripheral and puts acceptable current load on the pins. COUNT0 is the bit field used in all modes except in HB8 and HB16 modes with dual chip selects and quad chip selects when different baud rates are selected, see page 879 and page 885. If different baud rates are used, COUNT0 is associated with the address range specified by CS0n and COUNT1 is associated with the address range specified by CS1. The EPIBAUD2 register configures the baud rates for CS2n and CS3n. The COUNTn field is not a straight divider or count. The EPI Clock on EPI0S31 is related to the COUNTn field and the system clock as follows: If COUNTn = 0, EPIClockFreq = SystemClockFreq otherwise: EPIClockFreq = SystemClockFreq ⎛ ⎢COUNTn ⎥ ⎞ + 1⎟ × 2 ⎜⎢ ⎥ 2 ⎣ ⎦ ⎝ ⎠ where the symbol around COUNTn/2 is the floor operator, meaning the largest integer less than or equal to COUNTn/2. So, for example, a COUNTn of 0x0001 results in a clock rate of ½(system clock); a COUNTn of 0x0002 or 0x0003 results in a clock rate of ¼(system clock). The baud rate counter can also be configured as an integer divide by enabling INTDIV in the EPICFG register. When enabled, COUNTn of 0x0000 or 0x0001 results in a clock rate equal to system clock. COUNTn of 0x0002 results in a clock rate of 1/2 (system clock). COUNTn of 0x0003 results in a clock rate of 1/3 (system clock). EPI Main Baud Rate (EPIBAUD) Base 0x400D.0000 Offset 0x004 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 COUNT1 Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 COUNT0 Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 June 18, 2014 859 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 31:16 COUNT1 RW 0x0000 Description Baud Rate Counter 1 This bit field is only valid with multiple chip selects which are enabled when the CSCFG field is 0x2 or 0x3 or the CSCFGEXT field is set to 1, with CSCFG field as 0x1 or 0x2 and the CSBAUD bit is set in the EPIHBnCFG2 register. This bit field contains a counter used to divide the system clock by the count. A count of 0 means the system clock is used as is. 15:0 COUNT0 RW 0x0000 Baud Rate Counter 0 This bit field contains a counter used to divide the system clock by the count. A count of 0 means the system clock is used as is. 860 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: EPI Main Baud Rate (EPIBAUD2), offset 0x008 The system clock is used internally to the EPI Controller. The baud rate counter can be used to divide the system clock down to control the speed on the external interface. If the mode selected emits an external EPI clock, this register defines the EPI clock emitted. If the mode selected does not use an EPI clock, this register controls the speed of changes on the external interface. Care must be taken to program this register properly so that the speed of the external bus corresponds to the speed of the external peripheral and puts acceptable current load on the pins. COUNT0 and COUNT1 are used in quad chip select mode when different baud rates are selected, page 879 or page 885. If different baud rates are used, COUNT0 is associated with the address range specified by CS2n and COUNT1 is associated with the address range specified by CS3n. The COUNTn field is not a straight divider or count. The EPI Clock on EPI0S31 is related to the COUNTn field and the system clock as follows: If COUNTn = 0, EPIClockFreq = SystemClockFreq otherwise: EPIClockFreq = SystemClockFreq ⎛ ⎢COUNTn ⎥ ⎞ + 1⎟ × 2 ⎜⎢ ⎥ 2 ⎦ ⎝⎣ ⎠ where the symbol around COUNTn/2 is the floor operator, meaning the largest integer less than or equal to COUNTn/2. So, for example, a COUNTn of 0x0001 results in a clock rate of ½(system clock); a COUNTn of 0x0002 or 0x0003 results in a clock rate of ¼(system clock). EPI Main Baud Rate (EPIBAUD2) Base 0x400D.0000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 COUNT1 Type Reset COUNT0 Type Reset Bit/Field Name Type Reset 31:16 COUNT1 RW 0x0000 Description CS3n Baud Rate Counter 1 This bit field contains a counter used to divide the system clock by the count. A count of 0 means the system clock is unchanged. This bit field is only valid when quad chip selects are enabled by setting the CSCFGEXT bit to 1 and the CSCFG field to 0x1 or 0x2. In addition, the CSBAUD bit must be set in the EPIHBnCFG2 register. June 18, 2014 861 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 15:0 COUNT0 RW 0x0000 Description CS2n Baud Rate Counter 0 This bit field contains a counter used to divide the system clock by the count. A count of 0 means the system clock is unchanged. This bit field is only valid when quad chip selects are enabled by setting the CSCFGEXT to 1 and the CSCFG field to 0x1 or 0x2. In addition, the CSBAUD bit must be set in the EPIHBnCFG2 register. 862 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 4: EPI SDRAM Configuration (EPISDRAMCFG), offset 0x010 Important: The MODE field in the EPICFG register determines which configuration register is accessed for offsets 0x010 and 0x014. To access EPISDRAMCFG, the MODE field must be 0x1. The SDRAM Configuration register is used to specify several parameters for the SDRAM controller. Note that this register is reset when the MODE field in the EPICFG register is changed. If another mode is selected and the SDRAM mode is selected again, the values must be reinitialized. The SDRAM interface is designed to interface to x16 SDR SDRAMs of 64 MHz or higher, with the address and data pins overlapped (wire ORed on the board). See Table 11-3 on page 823 for pin assignments. EPI SDRAM Configuration (EPISDRAMCFG) Base 0x400D.0000 Offset 0x010 Type RW, reset 0x82EE.0000 31 30 29 RW 1 RW 0 RO 0 15 14 13 RO 0 RO 0 RO 0 FREQ Type Reset 28 27 26 25 24 23 22 RO 0 RO 0 RW 0 RW 1 RW 0 RW 1 RW 1 12 11 10 9 8 7 6 RO 0 RO 0 RO 0 RO 0 RO 0 reserved RO 0 20 19 18 17 16 RW 1 RW 0 RW 1 RW 1 RW 1 RW 0 5 4 3 2 1 0 RO 0 RO 0 RO 0 RW 0 RFSH reserved Type Reset 21 SLEEP RW 0 Bit/Field Name Type Reset 31:30 FREQ RW 0x2 reserved RO 0 SIZE RW 0 Description EPI Frequency Range This field configures the frequency range used for delay references by internal counters. This EPI frequency is the system frequency with the divider programmed by the COUNT0 bit in the EPIBAUDn register bit. This field affects the power up, precharge, and auto refresh delays. This field does not affect the refresh counting, which is configured separately using the RFSH field (and is based on system clock rate and number of rows per bank). The ranges are: Value Description 29:27 reserved RO 0x0 26:16 RFSH RW 0x2EE 0x0 0 - 15 MHz 0x1 15 - 30 MHz 0x2 30 - 50 MHz 0x3 50 - 100 MHz Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Refresh Counter This field contains the refresh counter in EPI clocks. The reset value of 0x2EE provides a refresh period of 64 ms when using a 50 MHz EPI clock. June 18, 2014 863 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 15:10 reserved RO 0x0 9 SLEEP RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sleep Mode Value Description 8:2 reserved RO 0 1:0 SIZE RW 0x0 0 No effect. 1 The SDRAM is put into low power state, but is self-refreshed. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Size of SDRAM The value of this field affects address pins and behavior. Value Description 0x0 64 megabits (8MB) 0x1 128 megabits (16MB) 0x2 256 megabits (32MB) 0x3 512 megabits (64MB) 864 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: EPI Host-Bus 8 Configuration (EPIHB8CFG), offset 0x010 Important: The MODE field in the EPICFG register determines which configuration register is accessed for offsets 0x010 and 0x014. To access EPIHB8CFG, the MODE field must be 0x2. The Host Bus 8 Configuration register is activated when the HB8 mode is selected. The HB8 mode supports muxed address/data (overlay of lower 8 address and all 8 data pins), separate address/data, and address-less FIFO mode. Note that this register is reset when the MODE field in the EPICFG register is changed. If another mode is selected and the HB8 mode is selected again, the values must be reinitialized. This mode is intended to support SRAMs, Flash memory (read), FIFOs, CPLDs/FPGAs, and devices with an MCU/HostBus slave or 8-bit FIFO interface support. Refer to Table 11-8 on page 831 for information on signal configuration controlled by this register and the EPIHB8CFG2 register. If less address pins are required, the corresponding AFSEL bit (page 770) should not be enabled so the EPI controller does not drive those pins, and they are available as standard GPIOs. EPI Host-Bus 8 Mode can be configured to use one to four chip selects with and without the use of ALE. If an alternative to chip selects are required, a chip enable can be handled in one of three ways: 1. Manually control via GPIOs. 2. Associate one or more upper address pins to CE. Because CE is normally CEn, lower addresses are not used. For example, if pins EPI0S27 and EPI0S26 are used for Device 1 and 0 respectively, then address 0x6800.0000 accesses Device 0 (Device 1 has its CEn high), and 0x6400.0000 accesses Device 1 (Device 0 has its CEn high). The pull-up behavior on the corresponding GPIOs must be properly configured to ensure that the pins are disabled when the interface is not in use. 3. With certain SRAMs, the ALE can be used as CEn because the address remains stable after the ALE strobe. The subsequent WRn or RDn signals write or read when ALE is low thus providing CEn functionality. EPI Host-Bus 8 Configuration (EPIHB8CFG) Base 0x400D.0000 Offset 0x010 Type RW, reset 0x0008.FF00 31 30 CLKGATE CLKGATEI Type Reset 29 28 27 CLKINV RDYEN IRDYINV 26 25 24 reserved 22 XFEEN 21 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 RW 1 RW 1 RW 1 RW 1 RW 1 WRWS RW 1 RW 1 RW 1 RW 0 20 19 18 WRHIGH RDHIGH ALEHIGH RW 0 MAXWAIT Type Reset 23 XFFEN RW 0 June 18, 2014 RW 0 RW 1 RO 0 RO 0 4 3 2 1 RDWS RW 0 17 reserved RW 0 RO 0 16 reserved RO 0 RO 0 0 MODE RW 0 RW 0 865 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 31 CLKGATE RW 0 Clock Gated Value Description 0 The EPI clock is free running. 1 The EPI clock is held low. Note: 30 CLKGATEI RW 0 A software application should only set the CLKGATE bit when there are no pending transfers or no EPI register access has been issued. Clock Gated when Idle Value Description 0 The EPI clock is free running. 1 The EPI clock is output only when there is data to write or read (current transaction); otherwise the EPI clock is held low. Note that EPI0S32 is an iRDY signal if RDYEN is set. CLKGATEI is ignored if CLKPIN is 0 or if the COUNT0 field in the EPIBAUD register is cleared. 29 CLKINV RW 0 Invert Output Clock Enable Value Description 28 RDYEN RW 0 0 No effect. 1 Invert EPI clock to ensure the rising edge is centered for outbound signal's setup and hold. Inbound signal is captured on rising edge EPI clock. Input Ready Enable Value Description 27 IRDYINV RW 0 0 No effect. 1 An external ready can be used to control the continuation of the current access. If this bit is set and the iRDY signal (EPIS032) is low, the current access is stalled. Input Ready Invert Value Description 26:24 reserved RO 0x0 0 No effect. 1 Invert the polarity of incoming external ready (iRDY signal). If this bit is set and the iRDY signal (EPIS032) is high the current access is stalled. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 866 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 23 XFFEN RW 0 Description External FIFO FULL Enable Value Description 22 XFEEN RW 0 0 No effect. 1 An external FIFO full signal can be used to control write cycles. If this bit is set and the FFULL full signal is high, XFIFO writes are stalled. External FIFO EMPTY Enable Value Description 21 WRHIGH RW 0 0 No effect. 1 An external FIFO empty signal can be used to control read cycles. If this bit is set and the FEMPTY signal is high, XFIFO reads are stalled. WRITE Strobe Polarity Value Description 20 RDHIGH RW 0 0 The WRITE strobe for CS0n is WRn (active Low). 1 The WRITE strobe for CS0n is WR (active High). READ Strobe Polarity Value Description 19 ALEHIGH RW 1 0 The READ strobe for CS0n is RDn (active Low). 1 The READ strobe for CS0n is RD (active High). ALE Strobe Polarity Value Description 18:16 reserved RO 0x0 15:8 MAXWAIT RW 0xFF 0 The address latch strobe for CS0n accesses is ALEn (active Low). 1 The address latch strobe for CS0n accesses is ALE (active High). Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Maximum Wait This field defines the maximum number of external clocks to wait while an external FIFO ready signal is holding off a transaction (FFULL and FEMPTY). When the MAXWAIT value is reached the ERRRIS interrupt status bit is set in the EPIRIS register. When this field is clear, the transaction can be held off forever without a system interrupt. Note: When the MODE field is configured to be 0x2 and the BLKEN bit is set in the EPICFG register, enabling HB8 mode, this field defaults to 0xFF. June 18, 2014 867 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 7:6 WRWS RW 0x0 Description Write Wait States This field adds wait states to the data phase of CS0n (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state adds 2 EPI clock cycles to the access time. The WRWSM bit in the EPIHB8TIME register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is not applicable in BURST mode. Value Description 0x0 Active WRn is 2 EPI clocks. 0x1 Active WRn is 4 EPI clocks. 0x2 Active WRn is 6 EPI clocks. 0x3 Active WRn is 8 EPI clocks. This field is used in conjunction with the EPIBAUD register. 5:4 RDWS RW 0x0 Read Wait States This field adds wait states to the data phase of CS0n (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB8TIME register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is not applicable in BURST mode. Value Description 0x0 Active RDn is 2 EPI clocks. 0x1 Active RDn is 4 EPI clocks. 0x2 Active RDn is 6 EPI clocks. 0x3 Active RDn is 8 EPI clocks. This field is used in conjunction with the EPIBAUD register 3:2 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 868 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1:0 MODE RW 0x0 Description Host Bus Sub-Mode This field determines which of four Host Bus 8 sub-modes to use. Sub-mode use is determined by the connected external peripheral. See Table 11-8 on page 831 for information on how this bit field affects the operation of the EPI signals. When used with multiple chip select option and the CSBAUD bit is set to 1 in the EPIHB8CFG2 register, this configuration is for CS0n. If the multiple chip select option is enabled and CSBAUD is clear, all chip-selects use the MODE encoding programmed in this register. Value Description 0x0 ADMUX – AD[7:0] Data and Address are muxed. 0x1 ADNONMUX – D[7:0] Data and address are separate. 0x2 Continuous Read - D[7:0] This mode is the same as ADNONMUX, but uses address switch for multiple reads instead of OEn strobing. 0x3 XFIFO – D[7:0] This mode adds XFIFO controls with sense of XFIFO full and XFIFO empty. This mode uses no address or ALE. Note that the XFIFO can only be used in asynchronous mode. June 18, 2014 869 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 6: EPI Host-Bus 16 Configuration (EPIHB16CFG), offset 0x010 Important: The MODE field in the EPICFG register determines which configuration register is accessed for offsets 0x010 and 0x014. To access EPIHB16CFG, the MODE field must be 0x3. The Host Bus 16 sub-configuration register is activated when the HB16 mode is selected. The HB16 mode supports muxed address/data (overlay of lower 16 address and all 16 data pins), separated address/data, and address-less FIFO mode. Note that this register is reset when the MODE field in the EPICFG register is changed. If another mode is selected and the HB16 mode is selected again, the values must be reinitialized. This mode is intended to support SRAMs, Flash memory (read), FIFOs, and CPLDs/FPGAs, and devices with an MCU/HostBus slave or 16-bit FIFO interface support. Refer to Table 11-9 on page 833 for information on signal configuration controlled by this register and the EPIHB16CFG2 register. If less address pins are required, the corresponding AFSEL bit (page 770) should not be enabled so the EPI controller does not drive those pins, and they are available as standard GPIOs. EPI Host-Bus 16 Mode can be configured to use one to four chip selects with and without the use of ALE. If an alternative to chip selects are required, a chip enable can be handled in one of three ways: 1. Manually control via GPIOs. 2. Associate one or more upper address pins to CE. Because CE is normally CEn, lower addresses are not used. For example, if pins EPI0S27 and EPI0S26 are used for Device 1 and 0 respectively, then address 0x6800.0000 accesses Device 0 (Device 1 has its CEn high), and 0x6400.0000 accesses Device 1 (Device 0 has its CEn high). The pull-up behavior on the corresponding GPIOs must be properly configured to ensure that the pins are disabled when the interface is not in use. 3. With certain SRAMs, the ALE can be used as CEn because the address remains stable after the ALE strobe. The subsequent WRn or RDn signals write or read when ALE is low thus providing CEn functionality. EPI Host-Bus 16 Configuration (EPIHB16CFG) Base 0x400D.0000 Offset 0x010 Type RW, reset 0x0008.FF00 31 30 CLKGATE CLKGATEI Type Reset 29 28 27 CLKINV RDYEN IRDYINV 26 25 24 reserved 22 XFEEN 21 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 RW 1 RW 1 RW 1 RW 1 RW 1 WRWS RW 1 RW 1 RW 1 RW 0 20 19 18 17 16 RDCRE BURST RW 0 RW 0 RW 0 1 WRHIGH RDHIGH ALEHIGH WRCRE RW 0 MAXWAIT Type Reset 23 XFFEN RW 0 870 RW 0 4 RDWS RW 0 RW 0 RW 1 3 2 reserved BSEL RO 0 RW 0 0 MODE RW 0 RW 0 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset Description 31 CLKGATE RW 0 Clock Gated Value Description 0 The EPI clock is free running. 1 The EPI clock is held low. Note: 30 CLKGATEI RW 0 A software application should only set the CLKGATE bit when there are no pending transfers or no EPI register access has been issued. Clock Gated Idle Value Description 0 The EPI clock is free running. 1 The EPI clock is output only when there is data to write or read (current transaction); otherwise the EPI clock is held low. Note that EPI0S32 is an iRDY signal if RDYEN is set. CLKGATEI is ignored if CLKPIN is 0 or if the COUNT0 field in the EPIBAUD register is cleared. 29 CLKINV RW 0 Invert Output Clock Enable Note: If operating in asynchronous mode, CLKINV must be 0. Value Description 28 RDYEN RW 0 0 No effect. 1 Invert EPI clock to ensure the rising edge is centered for outbound signal's setup and hold. Inbound signal is captured on rising edge EPI clock. Input Ready Enable Value Description 27 IRDYINV RW 0 0 No effect. 1 An external ready (iRDY) can be used to control the continuation of the current access. If this bit is set and the iRDY signal (EPIS032) is low, the current access is stalled. Input Ready Invert Value Description 26:24 reserved RO 0x00 0 No effect. 1 Invert polarity of incoming external ready. If this bit is set and the iRDY signal (EPIS032) is high the current access is stalled. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 871 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 23 XFFEN RW 0 Description External FIFO FULL Enable Value Description 22 XFEEN RW 0 0 No effect. 1 An external FIFO full signal can be used to control write cycles. If this bit is set and the FFULL signal is high, XFIFO writes are stalled. External FIFO EMPTY Enable Value Description 21 WRHIGH RW 0 0 No effect. 1 An external FIFO empty signal can be used to control read cycles. If this bit is set and the FEMPTY signal is high, XFIFO reads are stalled. WRITE Strobe Polarity Value Description 20 RDHIGH RW 0 0 The WRITE strobe for CS0n is WRn (active Low). 1 The WRITE strobe for CS0n is WR (active High). READ Strobe Polarity Value Description 19 ALEHIGH RW 1 0 The READ strobe for CS0n is RDn (active Low). 1 The READ strobe for CS0n is RD (active High). ALE Strobe Polarity Value Description 18 WRCRE RW 0 0 The address latch strobe for CS0n is ALEn (active Low). 1 The address latch strobe for CS0n is ALE (active High). PSRAM Configuration Register Write Used for PSRAM configuration registers. With WRCRE set, the next transaction by the EPI will be a write of the CR bit field in the EPIHBPSRAM register to the configuration register (CR) of the PSRAM. The WRCRE bit will self clear once the write-enabled CRE access is complete. Value Description 0 No Action. 1 Start CRE write transaction for CS0n. 872 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 17 RDCRE RW 0 Description PSRAM Configuration Register Read Enables read of PSRAM configuration registers. With the RDCRE set, the next access is a read of the PSRAM's Configuration Register (CR). This bit self clears once the read-enabled CRE access is complete. The address for the CRE access is located at EPIHBPSRAM[19:18]. The read data is returned on EPIHBPSRAM[15:0]. Value Description 16 BURST RW 0 0 No Action. 1 Start CRE read transaction for CS0n. Burst Mode Burst mode must be used with an ALE-enabled interface. Burst mode must be used with ADMUX, which is configured by the MODE field in the EPIHB16CFG register. Note: Burst mode is optimized for word-length accesses. Value Description 15:8 MAXWAIT RW 0xFF 0 Burst mode is disabled. 1 Burst mode is enabled for CS0n or single chip access. Maximum Wait This field defines the maximum number of external clocks to wait while an external FIFO ready signal is holding off a transaction (FFULL and FEMPTY). When this field is clear, the transaction can be held off forever without a system interrupt. Note: 7:6 WRWS RW 0x0 When the MODE field is configured to be 0x3 and the BLKEN bit is set in the EPICFG register, enabling HB16 mode, this field defaults to 0xFF. Write Wait States This field adds wait states to the data phase of CS0n (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state adds 2 EPI clock cycles to the access time. The WRWSM bit EPIHB16TIME register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is not applicable in BURST mode. Value Description 0x0 Active WRn is 2 EPI clocks. 0x1 Active WRn is 4 EPI clocks. 0x2 Active WRn is 6 EPI clocks. 0x3 Active WRn is 8 EPI clocks. This field is used in conjunction with the EPIBAUD register. June 18, 2014 873 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 5:4 RDWS RW 0x0 Description Read Wait States This field adds wait states to the data phase of CS0n (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB16TIME register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is not applicable in BURST mode. Value Description 0x0 Active RDn is 2 EPI clocks. 0x1 Active RDn is 4 EPI clocks. 0x2 Active RDn is 6 EPI clocks. 0x3 Active RDn is 8 EPI clocks. This field is used in conjunction with the EPIBAUD register 3 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 BSEL RW 0 Byte Select Configuration This bit enables byte select operation. Value Description 0 No Byte Selects Data is read and written as 16 bits. 1 Enable Byte Selects Two EPI signals function as byte select signals to allow 8-bit transfers. See Table 11-9 on page 833 for details on which EPI signals are used. Note: If BSEL = 0, byte accesses cannot be executed. 874 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1:0 MODE RW 0x0 Description Host Bus Sub-Mode This field determines which of three Host Bus 16 sub-modes to use. Sub-mode use is determined by the connected external peripheral. See Table 11-9 on page 833 for information on how this bit field affects the operation of the EPI signals. When used with multiple chip select option and the CSBAUD bit is set to 1 in the EPIHB16CFG2 register, this configuration is for CS0n. If the multiple chip select option is enabled and CSBAUD is clear, all chip-selects use the MODE encoding programmed in this register. Value Description 0x0 ADMUX – AD[15:0] Data and Address are muxed. 0x1 ADNONMUX – D[15:0] Data and address are separate. This mode is not practical in HB16 mode for normal peripherals because there are generally not enough address bits available. 0x2 Continuous Read - D[15:0] This mode is the same as ADNONMUX, but uses address switch for multiple reads instead of OEn strobing. This mode is not practical in HB16 mode for normal SRAMs because there are generally not enough address bits available. 0x3 XFIFO – D[15:0] This mode adds XFIFO controls with sense of XFIFO full and XFIFO empty. This mode uses no address or ALE. Note that the XFIFO can only be used in asynchronous mode. June 18, 2014 875 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 7: EPI General-Purpose Configuration (EPIGPCFG), offset 0x010 Important: The MODE field in the EPICFG register determines which configuration register is accessed for offsets 0x010 and 0x014. To access EPIGPCFG, the MODE field must be 0x0. The General-Purpose configuration register is used to configure the control, data, and address pins. This mode can be used for custom interfaces with FPGAs, CPLDs, and for digital data acquisition and actuator control. Note that this register is reset when the MODE field in the EPICFG register is changed. If another mode is selected and the General-purpose mode is selected again, the register the values must be reinitialized. This mode is designed for 3 general types of use: ■ Extremely high-speed clocked interfaces to FPGAs and CPLDs, with 3 sizes of data and optional address. Framing and clock-enable permit more optimized interfaces. ■ General parallel GPIO. From 1 to 32 pins may be written or read, with the speed precisely controlled by the baud rate in the EPIBAUD register (when used with the NBRFIFO and/or the WFIFO) or by rate of accesses from software or μDMA. ■ General custom interfaces of any speed. The configuration allows for choice of an output clock (free running or gated), a framing signal (with frame size), a ready input (to stretch transactions), read and write strobes, address of varying sizes, and data of varying sizes. Additionally, provisions are made for splitting address and data phases on the external interface. EPI General-Purpose Configuration (EPIGPCFG) Base 0x400D.0000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 CLKPIN CLKGATE Type Reset 28 27 reserved 26 25 24 FRM50 23 22 21 FRMCNT reserved 19 18 WR2CYC 17 16 reserved RW 0 RW 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RO 0 RO 0 RW 0 reserved Type Reset 20 RO 0 ASIZE Bit/Field Name Type Reset 31 CLKPIN RW 0 reserved DSIZE RW 0 Description Clock Pin Value Description 0 No clock output. 1 EPI0S31 functions as the EPI clock output. The EPI clock is generated from the COUNT0 field in the EPIBAUD register (as is the system clock which is divided down from it). 876 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset Description 30 CLKGATE RW 0 Clock Gated Value Description 0 The EPI clock is free running. 1 The EPI clock is output only when there is data to write or read (current transaction); otherwise the EPI clock is held low. CLKGATE is ignored if CLKPIN is 0 or if the COUNT0 field in the EPIBAUD register is cleared. 29:27 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 26 FRM50 RW 0 50/50 Frame Value Description 25:22 FRMCNT RW 0x0 0 The FRAME signal is output as a single pulse, and then held low for the count. 1 The FRAME signal is output as 50/50 duty cycle using count (see FRMCNT). Frame Count This field specifies the size of the frame in EPI clocks. The frame counter is used to determine the frame size. The count is FRMCNT+1. So, a FRMCNT of 0 forms a pure transaction valid signal (held high during transactions, low otherwise). A FRMCNT of 0 with FRM50 set inverts the FRAME signal on each transaction. A FRMCNT of 1 means the FRAME signal is inverted every other transaction; a value of 15 means every sixteenth transaction. If FRM50 is set, the frame is held high for FRMCNT+1 transactions, then held low for that many transactions, and so on. If FRM50 is clear, the frame is pulsed high for one EPI clock and then low for FRMCNT EPI clocks. 21:20 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 WR2CYC RW 0 2-Cycle Writes Value Description 0 Data is output on the same EPI clock cycle as the address. EPI clock begins toggling one cycle before the WR strobe goes High. 1 Writes are two EPI clock cycles long, with address on one EPI clock cycle (with the WR strobe asserted) and data written on the following EPI clock cycle (with WR strobe deasserted). The next address (if any) is in the cycle following. If the WR2CYC bit is set, the EPI clock begins toggling when the WR strobe goes High. When this bit is set, then the RW bit is forced to be set. June 18, 2014 877 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 18:6 reserved RO 0 5:4 ASIZE RW 0x0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Address Bus Size This field defines the size of the address bus. The address can be up to 4-bits wide with a 24-bit data bus, up to 12-bits wide with a 16-bit data bus, and up to 20-bits wide with an 8-bit data bus. If the full address bus is not used, use the least significant address bits. Any unused address bits can be used as GPIOs by clearing the AFSEL bit for the corresponding GPIOs. The values are: Value Description 0x0 No address 0x1 Up to 4 bits wide. 0x2 Up to 12 bits wide. This size cannot be used with 24-bit data. 0x3 Up to 20 bits wide. This size cannot be used with data sizes other than 8. 3:2 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1:0 DSIZE RW 0x0 Size of Data Bus This field defines the size of the data bus (starting at EPI0S0). Subsets of these numbers can be created by clearing the AFSEL bit for the corresponding GPIOs. Note that size 32 may not be used with clock, frame, address, or other control. The values are: Value Description 0x0 8 Bits Wide (EPI0S0 to EPI0S7) 0x1 16 Bits Wide (EPI0S0 to EPI0S15) 0x2 24 Bits Wide (EPI0S0 to EPI0S23) 0x3 32 Bits Wide (EPI0S0 to EPI0S31) This size may not be used with an EPI clock. This value is normally used for acquisition input and actuator control as well as other general-purpose uses that require 32 bits per direction. 878 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: EPI Host-Bus 8 Configuration 2 (EPIHB8CFG2), offset 0x014 Important: The MODE field in the EPICFG register determines which configuration register is accessed for offsets 0x010 and 0x014. To access EPIHB8CFG2, the MODE field of the EPICFG register must be 0x2. This register is used to configure operation while in Host-Bus 8 mode. Note that this register is reset when the MODE field in the EPICFG register is changed. If another mode is selected and the Host-Bus 8 mode is selected again, the values must be reinitialized. EPI Host-Bus 8 Configuration 2 (EPIHB8CFG2) Base 0x400D.0000 Offset 0x014 Type RW, reset 0x0008.0000 31 30 29 28 reserved Type Reset 27 26 CSCFGEXT CSBAUD 25 24 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 15 14 13 12 11 10 9 8 7 RO 0 RO 0 RO 0 RO 0 22 reserved reserved Type Reset 23 CSCFG 21 RO 0 RW 0 6 5 WRWS RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:28 reserved RO 0 RO 0 RW 0 20 19 18 WRHIGH RDHIGH ALEHIGH RW 0 RW 0 RW 1 RO 0 RO 0 4 3 2 1 RDWS RW 0 17 reserved RW 0 RO 0 16 reserved RO 0 RO 0 0 MODE RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 879 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 27 CSCFGEXT RW 0 Description Chip Select Extended Configuration This field is used in conjunction with CSCFG, to extend the chip select options, and ALE format. The values 0x0 through 0x3 are from the CSCFG field. The CSCFGEXT bit extends the values to 0x7. Value Description 0 CSCFG bit field is used in chip select configuration. 1 The CSCFG bit field is extended with CSCFGEXT representing the MSB. The possible chip select configurations when the CSCFGEXT bit is enabled are shown below: Table 11-14. CSCFGEXT + CSCFG Encodings Value Description 0x0 ALE Configuration EPI0S30 is used as an address latch (ALE). The ALE signal is generally used when the address and data are muxed (MODE field in the EPIHB8CFG register is 0x0). The ALE signal is used by an external latch to hold the address through the bus cycle. 0x1 CSn Configuration EPI0S30 is used as a Chip Select (CSn). When using this mode, the address and data are generally not muxed (MODE field in the EPIHB8CFG register is 0x1). However, if address and data muxing is needed, the WR signal (EPI0S29) and the RD signal (EPI0S28) can be used to latch the address when CSn is low. 0x2 Dual CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. This configuration can be used for a RAM bank split between 2 devices as well as when using both an external RAM and an external peripheral. 0x3 ALE with Dual CSn Configuration EPI0S30 is used as address latch (ALE), EPI0S27 is used as CS1n, and EPI0S26 is used as CS0n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. 0x4 ALE with Single CSn Configuration EPI0S30 is used as address latch (ALE) and EPI0S27 is used as CSn. 0x5 Quad CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. EPI0S34 is used as CS2n and EPI0S33 is used as CS3n. 0x6 ALE with Quad CSn Configuration EPI0S30 is used as ALE, EPI0S26 is CS0n, and EPI0S27 is used as CS1n. EPI0S34 is used as CS2n and EPI0S33 is used as CS3n. 0x7 Reserved 880 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 26 CSBAUD RW 0 Description Chip Select Baud Rate and Multiple Sub-Mode Configuration enable This bit is only valid when the CSCFGEXT + CSCFG field is programmed to 0x2 or 0x3, 0x5 or 0x6. This bit configures the baud rate settings for CS0n, CS1n, CS2n, and CS3n. This bit must also be set to allow different sub-mode configurations on chip-selects. If this bit is clear, all chip-select sub-modes are based on the MODE encoding defined in the EPI8HBCFG register. If the CSBAUD bit is set in the EPIHBnCFG2 register and dual- or quad-chip selects are enabled, then the individual chip selects can use different clock frequencies, wait states and strobe polarity. Value Description 0 Same Baud Rate and Same Sub-Mode All CSn use the baud rate for the external bus that is defined by the COUNT0 field in the EPIBAUD register and the sub-mode programmed in the MODE field of the EPIHB8CFG register. 1 Different Baud Rates CS0n uses the baud rate for the external bus that is defined by the COUNT0 field in the EPIBAUD register. CS1n uses the baud rate defined by the COUNT1 field in the EPIBAUD register. CS2n uses the baud rate for the external bus that is defined by the COUNT0 field in the EPIBAUD2 register. CS3n uses the baud rate defined by the COUNT1 field in the EPIBAUD2 register. In addition, the sub-modes for each chip select are individually programmed in their respective EPIHB8CFGn registers. June 18, 2014 881 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 25:24 CSCFG RW 0x0 Description Chip Select Configuration This field controls the chip select options, including an ALE format, a single chip select, two chip selects, and an ALE combined with two chip selects. These bits are also used in combination with the CSCFGEXT bit for further configurations, including quad- chip select. Value Description 0x0 ALE Configuration EPI0S30 is used as an address latch (ALE). The ALE signal is generally used when the address and data are muxed (HB8MODE field in the EPIHB8CFG register is 0x0). The ALE signal is used by an external latch to hold the address through the bus cycle. 0x1 CSn Configuration EPI0S30 is used as a Chip Select (CSn). When using this mode, the address and data are generally not muxed (HB8MODE field in the EPIHB8CFG register is 0x1). However, if address and data muxing is needed, the WR signal (EPI0S29) and the RD signal (EPI0S28) can be used to latch the address when CSn is low. 0x2 Dual CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. Whether CS0n or CS1n is asserted is determined by two methods. If only external RAM or external PER is enabled in the address map, the most significant address bit for a respective external address map controls CS0n or CS1n. If both external RAM and external PER is enabled, CS0n is mapped to PER and CS1n is mapped to RAM. This configuration can be used for a RAM bank split between 2 devices as well as when using both an external RAM and an external peripheral. 0x3 ALE with Dual CSn Configuration EPI0S30 is used as address latch (ALE), EPI0S27 is used as CS1n, and EPI0S26 is used as CS0n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. 23:22 reserved RO 0x0 21 WRHIGH RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS1n WRITE Strobe Polarity This field is used if the CSBAUD bit in the EPIHB8CFG2 register is enabled. Value Description 0 The WRITE strobe for CS1n accesses is WRn (active Low). 1 The WRITE strobe for CS1n accesses is WR (active High). 882 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 20 RDHIGH RW 0 Description CS1n READ Strobe Polarity This field is used if the CSBAUD bit in the EPIHB8CFG2 register is enabled. Value Description 19 ALEHIGH RW 1 0 The READ strobe for CS1n accesses is RDn (active Low). 1 The READ strobe for CS1n accesses is RD (active High). CS1n ALE Strobe Polarity This field is used if the CSBAUD bit in the EPIHB8CFG2 register is enabled. Value Description 18:8 reserved RO 0 7:6 WRWS RW 0x0 0 The address latch strobe for CS1n accesses is ALEn (active Low). 1 The address latch strobe for CS1n accesses is ALE (active High). Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS1n Write Wait States This field adds wait states to the data phase of CS1n accesses (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state encoding adds 2 EPI clock cycles to the access time. The WRWSM bit in the EPIHB8TIME2 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB8CFG2 register. This field is used in conjunction with the EPIBAUD register and is not applicable in BURST mode. Value Description 0x0 Active WRn is 2 EPI clocks. 0x1 Active WRn is 4 EPI clocks 0x2 Active WRn is 6 EPI clocks 0x3 Active WRn is 8 EPI clocks June 18, 2014 883 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 5:4 RDWS RW 0x0 Description CS1n Read Wait States This field adds wait states to the data phase of CS1n accesses (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state encoding adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB8TIME2 register can decrease the number of states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB8CFG2 register. This field is used in conjunction with the EPIBAUD register and is not applicable in BURST mode. Value Description 0x0 Active RDn is 2 EPI clocks 0x1 Active RDn is 4 EPI clocks 0x2 Active RDn is 6 EPI clocks 0x3 Active RDn is 8 EPI clocks 3:2 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1:0 MODE RW 0x0 CS1n Host Bus Sub-Mode This field determines which Host Bus 8 sub-mode to use for CS1n. Sub-mode use is determined by the externally connected peripheral or memory. See Table 11-8 on page 831 for information on how this bit field affects the operation of the EPI signals. Note: The CSBAUD bit must be set to enable this CS1n MODE field. If CSBAUD is clear, all chip-selects use the MODE configuration defined in the EPIHB8CFG register. Value Description 0x0 ADMUX – AD[7:0] Data and Address are muxed. 0x1 ADNONMUX – D[7:0] Data and address are separate. 0x2-0x3 reserved 884 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 9: EPI Host-Bus 16 Configuration 2 (EPIHB16CFG2), offset 0x014 Important: The MODE field in the EPICFG register determines which configuration register is accessed for offsets 0x010 and 0x014. To access EPIHB16CFG2, the MODE field must be 0x3. This register is used to configure operation while in Host-Bus 16 mode. Note that this register is reset when the MODE field in the EPICFG register is changed. If another mode is selected and the Host-Bus 16 mode is selected again, the values must be reinitialized. EPI Host-Bus 16 Configuration 2 (EPIHB16CFG2) Base 0x400D.0000 Offset 0x014 Type RW, reset 0x0008.0000 31 30 29 28 reserved Type Reset 27 26 CSCFGEXT CSBAUD 25 24 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 15 14 13 12 11 10 9 8 7 RO 0 RO 0 RO 0 RO 0 22 reserved reserved Type Reset 23 CSCFG 21 RO 0 RW 0 6 5 WRWS RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:28 reserved RO 0 RO 0 RW 0 20 19 18 WRHIGH RDHIGH ALEHIGH WRCRE RW 0 16 BURST RW 0 RW 0 RW 1 RW 0 RW 0 4 3 2 1 RDWS RW 0 17 RDCRE reserved RW 0 RO 0 RO 0 0 MODE RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 885 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 27 CSCFGEXT RW 0 Description Chip Select Extended Configuration This field is used in conjunction with CSCFG, to extend the chip select options, and ALE format. The values 0x0 through 0x3 are from the CSCFG field. The CSCFGEXT bit extends the values to 0x7. Value Description 0 CSCFG bit field is used in chip select configuration. 1 The CSCFG bit field is extended with CSCFGEXT representing the MSB. The possible chip select configurations when the CSCFGEXT bit is enabled are shown below: Table 11-15. CSCFGEXT + CSCFG Encodings Value Description 0x0 ALE Configuration EPI0S30 is used as an address latch (ALE). The ALE signal is generally used when the address and data are muxed (MODE field in the EPIHB16CFG register is 0x0). The ALE signal is used by an external latch to hold the address through the bus cycle. 0x1 CSn Configuration EPI0S30 is used as a Chip Select (CSn). When using this mode, the address and data are generally not muxed (MODE field in the EPIHB16CFG register is 0x1). However, if address and data muxing is needed, the WR signal (EPI0S29) and the RD signal (EPI0S28) can be used to latch the address when CSn is low. 0x2 Dual CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. This configuration can be used for a RAM bank split between 2 devices as well as when using both an external RAM and an external peripheral. 0x3 ALE with Dual CSn Configuration EPI0S30 is used as address latch (ALE), EPI0S27 is used as CS1n, and EPI0S26 is used as CS0n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. 0x4 ALE with Single CSn Configuration EPI0S30 is used as address latch (ALE) and EPI0S27 is used as CSn. 0x5 Quad CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. EPI0S34 is used as CS2n and EPI0S33 is used as CS3n. 0x6 ALE with Quad CSn Configuration EPI0S30 is used as ALE, EPI0S26 is CS0n, and EPI0S27 is used as CS1n. EPI0S34 is used as CS2n and EPI0S33 is used as CS3n. 0x7 Reserved 886 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 26 CSBAUD RW 0 Description Chip Select Baud Rate and Multiple Sub-Mode Configuration enable This bit is only valid when the CSCFGEXT + CSCFG field is programmed to 0x2 or 0x3, 0x5 or 0x6. This bit configures the baud rate settings for CS0n, CS1n, CS2n, and CS3n. This bit must also be set to allow different sub-mode configurations on chip-selects. If this bit is clear, all chip-select sub-modes are based on the MODE encoding defined in the EPI8HBCFG register. If the CSBAUD bit is set in the EPIHBnCFG2 register and dual- or quad-chip selects are enabled, then the individual chip selects can use different clock frequencies, wait states and strobe polarity. Value Description 0 Same Baud Rate and Same Sub-Mode All CSn use the baud rate for the external bus that is defined by the COUNT0 field in the EPIBAUD register and the sub-mode programmed in the MODE field of the EPIHB16CFG register. 1 Different Baud Rates CS0n uses the baud rate for the external bus that is defined by the COUNT0 field in the EPIBAUD register. CS1n uses the baud rate defined by the COUNT1 field in the EPIBAUD register. CS2n uses the baud rate for the external bus that is defined by the COUNT0 field in the EPIBAUD2 register. CS3n uses the baud rate defined by the COUNT1 field in the EPIBAUD2 register. In addition, the sub-modes for each chip select are individually programmed in their respective EPIHB16CFGn registers. June 18, 2014 887 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 25:24 CSCFG RW 0x0 Description Chip Select Configuration This field controls the chip select options, including an ALE format, a single chip select, two chip selects, and an ALE combined with two chip selects. These bits are also used in combination with the CSCFGEXT bit for further configurations, including quad- chip select. Value Description 0x0 ALE Configuration EPI0S30 is used as an address latch (ALE). When using this mode, the address and data should be muxed (HB16MODE field in the EPIHB16CFG register should be configured to 0x0). If needed, the address can be latched by external logic. 0x1 CSn Configuration EPI0S30 is used as a Chip Select (CSn). When using this mode, the address and data should not be muxed (MODE field in the EPIHB16CFG register should be configured to 0x1). In this mode, the WR signal (EPI0S29) and the RD signal (EPI0S28) are used to latch the address when CSn is low. 0x2 Dual CSn Configuration EPI0S30 is used as CS0n and EPI0S27 is used as CS1n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. This configuration can be used for a RAM bank split between 2 devices as well as when using both an external RAM and an external peripheral. 0x3 ALE with Dual CSn Configuration EPI0S30 is used as address latch (ALE), EPI0S27 is used as CS1n, and EPI0S26 is used as CS0n. Whether CS0n or CS1n is asserted is determined by the most significant address bit for a respective external address map. 23:22 reserved RO 0x0 21 WRHIGH RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS1n WRITE Strobe Polarity This field is used if CSBAUD bit of the EPIHB16CFG2 register is enabled. Value Description 20 RDHIGH RW 0 0 The WRITE strobe for CS1n accesses is WRn (active Low). 1 The WRITE strobe for CS1n accesses is WR (active High). CS1n READ Strobe Polarity This field is used if CSBAUD bit of the EPIHB16CFG2 register is enabled. Value Description 0 The READ strobe for CS1n accesses is RDn (active Low). 1 The READ strobe for CS1n accesses is RD (active High). 888 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 19 ALEHIGH RW 1 Description CS1n ALE Strobe Polarity This field is used if CSBAUD bit of the EPIHB16CFG2 register is enabled. Value Description 18 WRCRE RW 0 0 The address latch strobe for CS1n accesses is ALEn (active Low). 1 The address latch strobe for CS1n accesses is ALE (active High). CS1n PSRAM Configuration Register Write Used for the PSRAM configuration registers (CR). With WRCRE set, the next transaction by the EPI is a write of the CR bit field in the EPIHBPSRAM register to the configuration register (CR) of the PSRAM. The WRCRE bit self clears once the write-enabled CRE access is complete. Value Description 17 RDCRE RW 0 0 No Action. 1 Start CRE write transaction for CS1n. CS1n PSRAM Configuration Register Read Used for the PSRAM configuration registers (CR). With the RDCRE set, the next access is a read of the PSRAM's Configuration Register (CR). This bit self clears once the CRE access is complete. The address for the CRE access is located at EPIHBPSRAM[19:18]. The read data is returned on EPIHBPSRAM[15:0]. Value Description 16 BURST RW 0 0 No Action. 1 Start CRE read transaction for CS1n. CS1n Burst Mode Burst mode must be used with an ALE which is configured by programming the CSCFG and CSCFGEXT fields in the EPIHB16CFG2 register. Burst mode must be used in ADMUX, which is set by the MODE field in EPIHB16CFG2. Note: Burst mode is optimized for word-length accesses. Value Description 15:8 reserved RO 0x0 0 Burst mode is disabled. 1 Burst mode is enabled for CS1n. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 889 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 7:6 WRWS RW 0x0 Description CS1n Write Wait States This field adds wait states to the data phase of CS1n accesses (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state encoding adds 2 EPI clock cycles to the access time. The WRWSM bit in the EPIHB16TIME2 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB16CFG2 register. This field is used in conjunction with the EPIBAUD register and is not applicable in BURST mode. Value Description 5:4 RDWS RW 0x0 0x0 Active WRn is 2 EPI clocks 0x1 Active WRn is 4 EPI clocks. 0x2 Active WRn is 6 EPI clocks 0x3 Active WRn is 8 EPI clocks CS1n Read Wait States This field adds wait states to the data phase of CS1n accesses (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state encoding adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB16TIME2 register can decrease the number of states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB16CFG2 register. This field is used in conjunction with the EPIBAUD register and is not applicable in BURST mode. Value Description 3:2 reserved RO 0 0x0 Active RDn is 2 EPI clocks 0x1 Active RDn is 4 EPI clocks 0x2 Active RDn is 6 EPI clocks 0x3 Active RDn is 8 EPI clocks Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 890 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1:0 MODE RW 0x0 Description CS1n Host Bus Sub-Mode This field determines which Host Bus 16 sub-mode to use for CS1n. Sub-mode use is determined by the connected external peripheral. See Table 11-9 on page 833 for information on how this bit field affects the operation of the EPI signals. When used with multiple chip select option this configuration is for CS1n. Note: The CSBAUD bit must be set to enable this CS1n MODE field. If CSBAUD is clear, all chip-selects use the MODE configuration defined in the EPIHB16CFG register. Value Description 0x0 ADMUX – AD[15:0] Data and Address are muxed. 0x1 ADNONMUX – D[15:0] Data and address are separate. This mode is not practical in HB16 mode for normal peripherals because there are generally not enough address bits available. 0x2-0x3 reserved June 18, 2014 891 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 10: EPI Address Map (EPIADDRMAP), offset 0x01C This register enables address mapping. The EPI controller can directly address memory and peripherals. In addition, the EPI controller supports address mapping to allow indirect accesses in the External RAM and External Peripheral areas. If the external device is a peripheral, including a FIFO or a directly addressable device, the EPSZ and EPADR bit fields should be configured for the address space. If the external device is SDRAM, SRAM, or NOR Flash memory, the ERADR and ERSZ bit fields should be configured for the address space. If one of the dual chip select modes is selected (CSCFGEXT is 0x0 and CSCFG is 0x2 or 0x3 in the EPIHBnCFG2 register), both chip selects can share the peripheral or the memory space, or one chip select can use the peripheral space and the other can use the memory space. In the EPIADDRMAP register, if the EPADR field is not 0x0, the ECADR field is 0x0, and the ERADR field is 0x0, then the address specified by EPADR is used for both chip selects, with CS0n being asserted when the MSB of the address range is 0 and CS1n being asserted when the MSB of the address range is 1. If the ERADR field is not 0x0, the ECADR field is 0x0, and the EPADR field is 0x0, then the address specified by ERADR is used for both chip selects, with the MSB performing the same delineation. If both the EPADR and the ERADR are not 0x0 and the ECADR field is 0x0, then CS0n is asserted for either address range defined by EPADR and CS1n is asserted for either address range defined by ERADR. The two chip selects can also be shared between the code space and memory or peripheral space. If the ECADR field is 0x1, ERADR field is 0x0, and the EPADR field is not 0x0, then CS0n is asserted for the address range defined by ECADR and CS1n is asserted for either address range defined by EPADR. If the ECADR field is 0x1, EPADR field is 0x0, and the ERADR field is not 0x0, then CS0n is asserted for the address range defined by ECADR and CS1n is asserted for either address range defined by ERADR. If one of the Quad-Chip-Select modes is selected (CSCFGEXT is 0x1 and CSCFG is 0x2 or 0x3 in the EPIHBnCFG2 register), both the peripheral and the memory space must be enabled. In the EPIADDRMAP register, the EPADR field is 0x3, the ERADR field is 0x3, and the ECADR field is 0x0. In this case, CS0n maps to 0x6000.0000; CS1n maps to 0x8000.0000; CS2n maps to 0xA000.0000; and CS3n maps to 0xC000.0000. The MODE field of the EPIHBnCFGn registers configures the interface for the individual chip selects, which support ADMUX or ADNOMUX. If the CSBAUD bit is clear, all chip selects use the mode configured in the MODE bit field of the EPIHBnCFG register. Table 11-5 on page 828 gives a detailed explanation of chip select address range mappings based on which combinations of peripheral and memory space are enabled. EPI Address Map (EPIADDRMAP) Base 0x400D.0000 Offset 0x01C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 10 9 8 7 ECSZ RO 0 RW 0 ECADR RW 0 RW 0 RW 0 EPSZ RW 0 EPADR RW 0 892 RW 0 RW 0 ERSZ RW 0 ERADR RW 0 RW 0 RW 0 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 11:10 ECSZ RW 0x0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. External Code Size This field selects the size of the external code. If the size of the external code is larger, a bus fault occurs. If the size of the external peripheral is smaller, it wraps (upper address bits unused). Note: When not using byte selects in Host-Bus 16, data is accessed on 2-byte boundaries. As a result, the available address space is double the amount shown below. Value Description 9:8 ECADR RW 0x0 0x0 256 bytes; lower address range: 0x00 to 0xFF 0x1 64 KB; lower address range: 0x0000 to 0xFFFF 0x2 16 MB; lower address range: 0x00.0000 to 0xFF.FFFF 0x3 256MB; lower address range: 0x000.0000 to 0x0FFF.FFFF External Code Address This field selects address mapping for the external code area. Value Description 7:6 EPSZ RW 0x0 0x0 Not mapped 0x1 At 0x1000.0000 0x2 reserved 0x3 reserved External Peripheral Size This field selects the size of the external peripheral. If the size of the external peripheral is larger, a bus fault occurs. If the size of the external peripheral is smaller, it wraps (upper address bits unused). Note: When not using byte selects in Host-Bus 16, data is accessed on 2-byte boundaries. As a result, the available address space is double the amount shown below. Value Description 0x0 256 bytes; lower address range: 0x00 to 0xFF 0x1 64 KB; lower address range: 0x0000 to 0xFFFF 0x2 16 MB; lower address range: 0x00.0000 to 0xFF.FFFF 0x3 256 MB; lower address range: 0x000.0000 to 0xFFF.FFFF June 18, 2014 893 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 5:4 EPADR RW 0x0 Description External Peripheral Address This field selects address mapping for the external peripheral area. Value Description 3:2 ERSZ RW 0x0 0x0 Not mapped 0x1 At 0xA000.0000 0x2 At 0xC000.0000 0x3 Only to be used with Host Bus quad chip select. In quad chip select mode, CS2n maps to 0xA000.0000 and CS3n maps to 0xC000.0000. External RAM Size This field selects the size of mapped RAM. If the size of the external memory is larger, a bus fault occurs. If the size of the external memory is smaller, it wraps (upper address bits unused): Value Description 1:0 ERADR RW 0x0 0x0 256 bytes; lower address range: 0x00 to 0xFF 0x1 64 KB; lower address range: 0x0000 to 0xFFFF 0x2 16 MB; lower address range: 0x00.0000 to 0xFF.FFFF 0x3 256 MB; lower address range: 0x000.0000 to 0xFFF.FFFF External RAM Address Selects address mapping for external RAM area: Value Description 0x0 Not mapped 0x1 At 0x6000.0000 0x2 At 0x8000.0000 0x3 Only to be used with Host Bus quad chip select. In quad chip select mode, CS0n maps to 0x6000.0000 and CS1n maps to 0x8000.0000. 894 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: EPI Read Size 0 (EPIRSIZE0), offset 0x020 Register 12: EPI Read Size 1 (EPIRSIZE1), offset 0x030 This register selects the size of transactions when performing non-blocking reads with the EPIRPSTDn registers. This size affects how the external address is incremented. The SIZE field must match the external data width as configured in the EPIHBnCFG or EPIGPCFG register. SDRAM mode uses a 16-bit data interface. If SIZE is 0x1, data is returned on the least significant bits (D[7:0]), and the remaining bits D[31:8] are all zeros, therefore the data on bits D[15:8] is lost. If SIZE is 0x2, data is returned on the least significant bits (D[15:0]), and the remaining bits D[31:16] are all zeros. Note that changing this register while a read is active has an unpredictable effect. EPI Read Size n (EPIRSIZEn) Base 0x400D.0000 Offset 0x020 Type RW, reset 0x0000.0003 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:2 reserved RO 0x0000.000 1:0 SIZE RW 0x3 0 SIZE RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 1 RW 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Current Size Value Description 0x0 reserved 0x1 Byte (8 bits) 0x2 Half-word (16 bits) 0x3 Word (32 bits) June 18, 2014 895 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 13: EPI Read Address 0 (EPIRADDR0), offset 0x024 Register 14: EPI Read Address 1 (EPIRADDR1), offset 0x034 This register holds the current address value. When performing non-blocking reads via the EPIRPSTDn registers, this register's value forms the address (when used by the mode). That is, when an EPIRPSTDn register is written with a non-0 value, this register is used as the first address. After each read, it is incremented by the size specified by the corresponding EPIRSIZEn register. Thus at the end of a read, this register contains the next address for the next read. For example, if the last read was 0x20, and the size is word, then the register contains 0x24. When a non-blocking read is cancelled, this register contains the next address that would have been read had it not been cancelled. For example, if reading by bytes and 0x103 had been read but not 0x104, this register contains 0x104. In this manner, the system can determine the number of values in the NBRFIFO to drain. Note that changing this register while a read is active has an unpredictable effect due to race condition. EPI Read Address n (EPIRADDRn) Base 0x400D.0000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 ADDR Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 ADDR Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type 31:0 ADDR RW RW 0 Reset RW 0 Description 0x0000.0000 Current Address Next address to read. 896 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 15: EPI Non-Blocking Read Data 0 (EPIRPSTD0), offset 0x028 Register 16: EPI Non-Blocking Read Data 1 (EPIRPSTD1), offset 0x038 This register sets up a non-blocking read via the external interface. A non-blocking read is started by writing to this register with the count (other than 0). Clearing this register terminates an active non-blocking read as well as cancelling any that are pending. This register should always be cleared before writing a value other than 0; failure to do so can cause improper operation. Note that both NBR channels can be enabled at the same time, but NBR channel 0 has the highest priority and channel 1 does not start until channel 0 is finished. The first address is based on the corresponding EPIRADDRn register. The address register is incremented by the size specified by the EPIRSIZEn register after each read. If the size is less than a word, only the least significant bits of data are filled into the NBRFIFO; the most significant bits are cleared. Note that all three registers may be written using one STM instruction, such as with a structure copy in C/C++. The data may be read from the EPIREADFIFO register after the read cycle is completed. The interrupt mechanism is normally used to trigger the FIFO reads via ISR or μDMA. If the countdown has not reached 0 and the NBRFIFO is full, the external interface waits until a NBRFIFO entry becomes available to continue. Note: if a blocking read or write is performed through the address mapped area (at 0x6000.0000 through 0xDFFF.FFFF), any current non-blocking read is paused (at the next safe boundary), and the blocking request is inserted. After completion of any blocking reads or writes, the non-blocking reads continue from where they were paused. The other way to read data is via the address mapped locations (see the EPIADDRMAP register), but this method is blocking (core or μDMA waits until result is returned). To cancel a non-blocking read, clear this register. To make sure that all values read are drained from the NBRFIFO, the EPISTAT register must be consulted to be certain that bits NBRBUSY and ACTIVE are cleared. One of these registers should not be cleared until either the other EPIRPSTDn register becomes active or the external interface is not busy. At that point, the corresponding EPIRADDRn register indicates how many values were read. EPI Non-Blocking Read Data n (EPIRPSTDn) Base 0x400D.0000 Offset 0x028 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 15 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 14 13 12 11 10 9 8 7 reserved Type Reset RO 0 RO 0 POSTCNT RO 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:13 reserved RO 0x0000.0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 897 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 12:0 POSTCNT RW 0x000 Post Count A write of a non-zero value starts a read operation for that count. Note that it is the software's responsibility to handle address wrap-around. Reading this register provides the current count. A write of 0 cancels a non-blocking read (whether active now or pending). Prior to writing a non-zero value, this register must first be cleared. 898 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 17: EPI Status (EPISTAT), offset 0x060 This register indicates which non-blocking read register is currently active; it also indicates whether the external interface is busy performing a write or non-blocking read (it cannot be performing a blocking read, as the bus would be blocked and as a result, this register could not be accessed). This register is useful to determining which non-blocking read register is active when both are loaded with values and when implementing sequencing or sharing. This register is also useful when canceling non-blocking reads, as it shows how many values were read by the canceled side. EPI Status (EPISTAT) Base 0x400D.0000 Offset 0x060 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 reserved Type Reset reserved Type Reset RO 0 XFFULL XFEMPTY INITSEQ Bit/Field Name Type Reset 31:9 reserved RO 0x0000.00 8 XFFULL RO 0 RO 0 RO 0 WBUSY NBRBUSY RO 0 RO 0 RO 0 reserved RO 0 RO 0 ACTIVE RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. External FIFO Full This bit provides information on the XFIFO when in the FIFO sub-mode of the Host Bus n mode with the XFFEN bit set in the EPIHBnCFG register. The EPI0S26 signal reflects the status of this bit. Value Description 0 The external device is not gating the clock. 1 The XFIFO is signaling as full (the FIFO full signal is high). Attempts to write in this case are stalled until the XFIFO full signal goes low or the counter times out as specified by the MAXWAIT field. 7 XFEMPTY RO 0 External FIFO Empty This bit provides information on the XFIFO when in the FIFO sub-mode of the Host Bus n mode with the XFEEN bit set in the EPIHBnCFG register. The EPI0S27 signal reflects the status of this bit. Value Description 0 The external device is not gating the clock. 1 The XFIFO is signaling as empty (the FIFO empty signal is high). Attempts to read in this case are stalled until the XFIFO empty signal goes low or the counter times out as specified by the MAXWAIT field. June 18, 2014 899 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 6 INITSEQ RO 0 Description Initialization Sequence Value Description 0 The SDRAM interface is not in the wakeup period. 1 The SDRAM interface is running through the wakeup period (greater than 100 μs). If an attempt is made to read or write the SDRAM during this period, the access is held off until the wakeup period is complete. 5 WBUSY RO 0 Write Busy Value Description 4 NBRBUSY RO 0 0 The external interface is not performing a write. 1 The external interface is performing a write. Non-Blocking Read Busy Value Description 3:1 reserved RO 0x0 0 ACTIVE RO 0 0 The external interface is not performing a non-blocking read. 1 The external interface is performing a non-blocking read, or if the non-blocking read is paused due to a write. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Register Active Value Description 0 If NBRBUSY is set, the EPIRPSTD0 register is active. If the NBRBUSY bit is clear, then neither EPIRPSTDx register is active. 1 The EPIRPSTD1 register is active. 900 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 18: EPI Read FIFO Count (EPIRFIFOCNT), offset 0x06C This register returns the number of values in the NBRFIFO (the data in the NBRFIFO can be read via the EPIREADFIFO register). A race is possible, but that only means that more values may come in after this register has been read. EPI Read FIFO Count (EPIRFIFOCNT) Base 0x400D.0000 Offset 0x06C Type RO, reset 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO - RO - RO - RO - reserved Type Reset reserved Type Reset COUNT Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 COUNT RO - Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. FIFO Count Number of filled entries in the NBRFIFO. June 18, 2014 901 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 19: EPI Read FIFO (EPIREADFIFO0), offset 0x070 Register 20: EPI Read FIFO Alias 1 (EPIREADFIFO1), offset 0x074 Register 21: EPI Read FIFO Alias 2 (EPIREADFIFO2), offset 0x078 Register 22: EPI Read FIFO Alias 3 (EPIREADFIFO3), offset 0x07C Register 23: EPI Read FIFO Alias 4 (EPIREADFIFO4), offset 0x080 Register 24: EPI Read FIFO Alias 5 (EPIREADFIFO5), offset 0x084 Register 25: EPI Read FIFO Alias 6 (EPIREADFIFO6), offset 0x088 Register 26: EPI Read FIFO Alias 7 (EPIREADFIFO7), offset 0x08C Important: This register is read-sensitive. See the register description for details. This register returns the contents of the NBRFIFO or 0 if the NBRFIFO is empty. Each read returns the data that is at the top of the NBRFIFO, and then empties that value from the NBRFIFO. The alias registers can be used with the LDMIA instruction for more efficient operation (for up to 8 registers). See Cortex™-M3/M4 Instruction Set Technical User's Manual (literature number SPMU159) for more information on the LDMIA instruction. EPI Read FIFn (EPIREADFIFOn) Base 0x400D.0000 Offset 0x070 Type RO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - RO - DATA Type Reset DATA Type Reset Bit/Field Name Type Reset Description 31:0 DATA RO - Reads Data This field contains the data that is at the top of the NBRFIFO. After being read, the NBRFIFO entry is removed. 902 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 27: EPI FIFO Level Selects (EPIFIFOLVL), offset 0x200 This register allows selection of the FIFO levels which trigger an interrupt to the interrupt controller or, more efficiently, a DMA request to the μDMA. The NBRFIFO select triggers on fullness such that it triggers on match or above (more full) in order for the processor or the μDMA to extract the read data. The WFIFO triggers on emptiness such that it triggers on match or below (less entries) in order for the processor or the μDMA to insert more write data. It should be noted that the FIFO triggers are not identical to other such FIFOs in TM4C1294NCPDT peripherals. In particular, empty and full triggers are provided to avoid wait states when using blocking operations. The settings in this register are only meaningful if the μDMA is active or the interrupt is enabled. Additionally, this register allows protection against writes stalling and notification of performing blocking reads which stall for extra time due to preceding writes. The two functions behave in a non-orthogonal way because read and write are not orthogonal. The write error bit configures the system such that an attempted write to an already full WFIFO abandons the write and signals an error interrupt to prevent accidental latencies due to stalling writes. The read error bit configures the system such that after a read has been stalled due to any preceding writes in the WFIFO, the error interrupt is generated. Note that the excess stall is not prevented, but an interrupt is generated after the fact to notify that it has happened. EPI FIFO Level Selects (EPIFIFOLVL) Base 0x400D.0000 Offset 0x200 Type RW, reset 0x0000.0033 31 30 29 28 27 26 25 24 23 22 21 20 19 18 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 6 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 WRFIFO RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:18 reserved RO 0x0000 17 WFERR RW 0 RO 0 RO 0 RW 0 RW 1 RO 0 RO 0 3 2 reserved RW 1 RO 0 17 16 WFERR RSERR RW 0 RW 0 1 0 RDFIFO RW 0 RW 1 RW 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Write Full Error Value Description 0 The Write Full error interrupt is disabled. Writes are stalled when the WFIFO is full until a space becomes available but an error is not generated. Note that the Cortex-M3 write buffer may hide that stall if no other memory transactions are attempted during that time. 1 This bit enables the Write Full error interrupt (WTFULL in the EPIEISC register) to be generated when a write is attempted and the WFIFO is full. The write stalls until a WFIFO entry becomes available. June 18, 2014 903 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 16 RSERR RW 0 Description Read Stall Error Value Description 0 The Read Stalled error interrupt is disabled. Reads behave as normal and are stalled until any preceding writes have completed and the read has returned a result. 1 This bit enables the Read Stalled error interrupt (RSTALL in the EPIEISC register) to be generated when a read is attempted and the WFIFO is not empty. The read is still stalled during the time the WFIFO drains, but this error notifies the application that this excess delay has occurred. Note that the configuration of this bit has no effect on non-blocking reads. 15:7 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 6:4 WRFIFO RW 0x3 Write FIFO Value Description 0x0 Interrupt is triggered while WRFIFO is empty. It will be deasserted when not empty. This encoding is optimized for burst of 4 writes. 0x1 reserved 0x2 Interrupt is triggered until there are only two slots available. Thus, trigger is deasserted when there are two WRFIFO entries present. This configuration is optimized for bursts of 2. 0x3 Interrupt is triggered until there is one WRFIFO entry available. This configuration expects only single writes. 0x4 Trigger interrupt when WRFIFO is not full, meaning trigger will continue to assert until there are four entries in the WRFIFO. 0x5-0x7 reserved 3 reserved RO 0 2:0 RDFIFO RW 0x3 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Read FIFO This field configures the trigger point for the NBRFIFO. Value Description 0x0 reserved 0x1 Trigger when there are 1 or more entries in the NBRFIFO. 0x2 Trigger when there are 2 or more entries in the NBRFIFO. 0x3 Trigger when there are 4 or more entries in the NBRFIFO. 0x4 Trigger when there are 6 or more entries in the NBRFIFO. 0x5 Trigger when there are 7 or more entries in the NBRFIFO. 0x6 Trigger when there are 8 entries in the NBRFIFO. 0x7 reserved 904 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 28: EPI Write FIFO Count (EPIWFIFOCNT), offset 0x204 This register contains the number of slots currently available in the WFIFO. This register may be used for polled writes to avoid stalling and for blocking reads to avoid excess stalling (due to undrained writes). An example use for writes may be: for (idx = 0; idx < cnt; idx++) { while (EPIWFIFOCNT == 0) ; *ext_ram = *mydata++; } The above code ensures that writes to the address mapped location do not occur unless the WFIFO has room. Although polling makes the code wait (spinning in the loop), it does not prevent interrupts being serviced due to bus stalling. EPI Write FIFO Count (EPIWFIFOCNT) Base 0x400D.0000 Offset 0x204 Type RO, reset 0x0000.0004 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:3 reserved RO 0x0000.000 2:0 WTAV RO 0x4 WTAV RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Available Write Transactions The number of write transactions available in the WFIFO. When clear, a write is stalled waiting for a slot to become free (from a preceding write completing). June 18, 2014 905 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 29: EPI DMA Transmit Count (EPIDMATXCNT), offset 0x208 This register is used to program the total number of transfers (byte, halfword or word) by the µDMA to WRFIFO. As each transfer is processed by the EPI, the TXCNT bit field value is decreased by 1. When TXCNT = 0, the EPI's uDMA request signal is deasserted. EPI DMA Transmit Count (EPIDMATXCNT) Base 0x400D.0000 Offset 0x208 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset TXCNT Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 TXCNT RW 0x0000 DMA Count This field is used to program the total number of transfers (byte, halfword or word) from the µDMA to the EPI WRFIFO. 906 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 30: EPI Interrupt Mask (EPIIM), offset 0x210 This register is the interrupt mask set or clear register. For each interrupt source (read, write, and error), a mask value of 1 allows the interrupt source to trigger an interrupt to the interrupt controller; a mask value of 0 prevents the interrupt source from triggering an interrupt. EPI Interrupt Mask (EPIIM) Base 0x400D.0000 Offset 0x210 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 WRIM RDIM ERRIM RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 DMAWRIM DMARDIM RW 0 RW 0 Bit/Field Name Type Reset Description 31:5 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 DMAWRIM RW 0 Write uDMA Interrupt Mask Value Description 3 DMARDIM RW 0 0 DMAWRRIS in the EPIRIS register is masked and does not cause an interrupt. 1 DMAWRRIS in the EPIRIS register is not masked and can trigger an interrupt to the interrupt controller. Read uDMA Interrupt Mask Value Description 2 WRIM RW 0 0 DMARDRIS in the EPIRIS register is masked and does not cause an interrupt. 1 DMARDRIS in the EPIRIS register is not masked and can trigger an interrupt to the interrupt controller. Write FIFO Empty Interrupt Mask Value Description 0 WRRIS in the EPIRIS register is masked and does not cause an interrupt. 1 WRRIS in the EPIRIS register is not masked and can trigger an interrupt to the interrupt controller. June 18, 2014 907 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 1 RDIM RW 0 Description Read FIFO Full Interrupt Mask Value Description 0 ERRIM RW 0 0 RDRIS in the EPIRIS register is masked and does not cause an interrupt. 1 RDRIS in the EPIRIS register is not masked and can trigger an interrupt to the interrupt controller. Error Interrupt Mask Value Description 0 ERRIS in the EPIRIS register is masked and does not cause an interrupt. 1 ERRIS in the EPIRIS register is not masked and can trigger an interrupt to the interrupt controller. 908 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 31: EPI Raw Interrupt Status (EPIRIS), offset 0x214 This register is the raw interrupt status register. On a read, it gives the current state of each interrupt source. A write has no effect. Note that raw status for read and write is set or cleared based on FIFO fullness as controlled by EPIFIFOLVL. Raw status for error is held until the error is cleared by writing to the EPIEISC register. EPI Raw Interrupt Status (EPIRIS) Base 0x400D.0000 Offset 0x214 Type RO, reset 0x0000.0004 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 WRRIS RDRIS ERRRIS RO 0 RO 0 RO 0 RO 0 RO 1 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 DMAWRRIS DMARDRIS RO 0 RO 0 Bit/Field Name Type Reset Description 31:5 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 DMAWRRIS RO 0 Write uDMA Raw Interrupt Status Value Description 0 The write uDMA has not completed. 1 The write uDMA has completed. This bit is cleared by writing a 1 to the DMAWRIC bit in the EPIEISC register. 3 DMARDRIS RO 0 Read uDMA Raw Interrupt Status Value Description 0 The read uDMA has not completed. 1 The read uDMA has completed. This bit is cleared by writing a 1 to the DMARDIC bit in the EPIEISC register. June 18, 2014 909 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 2 WRRIS RO 1 Description Write Raw Interrupt Status Value Description 0 The number of available entries in the WFIFO is above the range specified by the WRFIFO field in the EPIFIFOLVL register. 1 The number of available entries in the WFIFO is within the trigger range specified by the WRFIFO field in the EPIFIFOLVL register. This bit is cleared when the level in the WFIFO is above the trigger point programmed by the WRFIFO field. 1 RDRIS RO 0 Read Raw Interrupt Status Value Description 0 The number of valid entries in the NBRFIFO is below the trigger range specified by the RDFIFO field in the EPIFIFOLVL register. 1 The number of valid entries in the NBRFIFO is in the trigger range specified by the RDFIFO field in the EPIFIFOLVL register. This bit is cleared when the level in the NBRFIFO is below the trigger point programmed by the RDFIFO field. 0 ERRRIS RO 0 Error Raw Interrupt Status The error interrupt occurs in the following situations: ■ WFIFO Full. For a full WFIFO to generate an error interrupt, the WFERR bit in the EPIFIFOLVL register must be set. ■ Read Stalled. For a stalled read to generate an error interrupt, the RSERR bit in the EPIFIFOLVL register must be set. ■ Timeout. If the MAXWAIT field in the EPIHBnCFG register is configured to a value other than 0, a timeout error occurs when XFIFO not-ready signals hold a transaction for more than the count in the MAXWAIT field. Value Description 0 An error has not occurred. 1 A WFIFO Full, a Read Stalled, or a Timeout error has occurred. To determine which error occurred, read the status of the EPI Error Interrupt Status and Clear (EPIEISC) register. This bit is cleared by writing a 1 to the bit in the EPIEISC register that caused the interrupt. 910 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 32: EPI Masked Interrupt Status (EPIMIS), offset 0x218 This register is the masked interrupt status register. On read, it gives the current state of each interrupt source (read, write, and error) after being masked via the EPIIM register. A write has no effect. The values returned are the ANDing of the EPIIM and EPIRIS registers. If a bit is set in this register, the interrupt is sent to the interrupt controller. EPI Masked Interrupt Status (EPIMIS) Base 0x400D.0000 Offset 0x218 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 4 3 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 10 9 8 7 6 5 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 DMAWRMIS DMARDMIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 2 1 0 WRMIS RDMIS ERRMIS RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:5 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 DMAWRMIS RO 0 Write uDMA Masked Interrupt Status Value Description 0 The write uDMA has not completed or the interrupt is masked. 1 The write uDMA has completed and the DMAWRIM bit in the EPIIM register is set, triggering an interrupt to the interrupt controller. This bit is cleared by writing a 1 to the DMAWRIC bit in the EPIEISC register. 3 DMARDMIS RO 0 Read uDMA Masked Interrupt Status Value Description 0 The read uDMA has not completed or the interrupt is masked. 1 The read uDMA has completed and the DMAWRIM bit in the EPIIM register is set, triggering an interrupt to the interrupt controller. This bit is cleared by writing a 1 to the DMARDIC bit in the EPIEISC register. June 18, 2014 911 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 2 WRMIS RO 0 Description Write Masked Interrupt Status Value Description 1 RDMIS RO 0 0 The number of available entries in the WFIFO is above the range specified by the trigger level or the interrupt is masked. 1 The number of available entries in the WFIFO is within the range specified by the trigger level (the WRFIFO field in the EPIFIFOLVL register) and the WRIM bit in the EPIIM register is set, triggering an interrupt to the interrupt controller. Read Masked Interrupt Status Value Description 0 ERRMIS RO 0 0 The number of valid entries in the NBRFIFO is below the range specified by the trigger level or the interrupt is masked. 1 The number of valid entries in the NBRFIFO is within the range specified by the trigger level (the RDFIFO field in the EPIFIFOLVL register) and the RDIM bit in the EPIIM register is set, triggering an interrupt to the interrupt controller. Error Masked Interrupt Status Value Description 0 An error has not occurred or the interrupt is masked. 1 A WFIFO Full, a Read Stalled, or a Timeout error has occurred and the ERIM bit in the EPIIM register is set, triggering an interrupt to the interrupt controller. 912 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 33: EPI Error and Interrupt Status and Clear (EPIEISC), offset 0x21C This register is used to clear a pending error interrupt. Clearing any defined bit in the EPIEISC has no effect; setting a bit clears the error source and the raw error returns to 0. When any of bits[2:0] of this register are read as set, it indicates that the ERRRIS bit in the EPIRIS register is set and an EPI controller error is sent to the interrupt controller if the ERIM bit in the EPIIM register is set. If any of bits [2:0] are written as 1, the register bit being written to, as well as the ERRIS bit in the EPIRIS register and the ERIM bit in the EPIIM register are cleared.If the DMAWRIC or DMARDIC bit in this register is set, then the corresponding bit in the EPIRIS and EPIMIS register is cleared. Note that writing to this register and reading back immediately (pipelined by the processor) returns the old register contents. One cycle is needed between write and read. EPI Error and Interrupt Status and Clear (EPIEISC) Base 0x400D.0000 Offset 0x21C Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 DMAWRIC DMARDIC WTFULL W1C 0 W1C 0 RW1C 0 RSTALL TOUT RW1C 0 RW1C 0 Bit/Field Name Type Reset Description 31:5 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 DMAWRIC W1C 0 Write uDMA Interrupt Clear Writing a 1 to this bit clears the DMAWRRIS bit in the EPIRIS register and the DMAWRMIS bit in the EPIMIS register. 3 DMARDIC W1C 0 Read uDMA Interrupt Clear Writing a 1 to this bit clears the DMARDRIS bit in the EPIRIS register and the DMARDMIS bit in the EPIMIS register. 2 WTFULL RW1C 0 Write FIFO Full Error Value Description 0 The WFERR bit is not enabled or no writes are stalled. 1 The WFERR bit is enabled and a write is stalled due to the WFIFO being full. Writing a 1 to this bit clears it, as well as the ERRRIS and ERIM bits. 1 RSTALL RW1C 0 Read Stalled Error Value Description 0 The RSERR bit is not enabled or no pending reads are stalled. 1 The RSERR bit is enabled and a pending read is stalled due to writes in the WFIFO. Writing a 1 to this bit clears it, as well as the ERRRIS and ERIM bits. June 18, 2014 913 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 0 TOUT RW1C 0 Description Timeout Error This bit is the timeout error source. The timeout error occurs when the XFIFO not-ready signals hold a transaction for more than the count in the MAXWAIT field (when not 0). Value Description 0 No timeout error has occurred. 1 A timeout error has occurred. Writing a 1 to this bit clears it, as well as the ERRRIS and ERIM bits. 914 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 34: EPI Host-Bus 8 Configuration 3 (EPIHB8CFG3), offset 0x308 Important: The MODE field in the EPICFG register configures whether EPI Host Bus mode is enabled. For EPIHB8CFG3 to be valid, the MODE field must be 0x2. EPI Host-Bus 8 Configuration 3 (EPIHB8CFG3) Base 0x400D.0000 Offset 0x308 Type RW, reset 0x0008.0000 31 30 29 28 27 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 26 25 24 23 22 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 1 RO 0 RO 0 RO 0 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RW 0 reserved Type Reset WRWS RO 0 20 19 18 WRHIGH RDHIGH ALEHIGH reserved Type Reset 21 RDWS 17 16 reserved reserved MODE RW 0 Bit/Field Name Type Reset Description 31:22 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 21 WRHIGH RW 0 CS2n WRITE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB8CFG2. Value Description 20 RDHIGH RW 0 0 The WRITE strobe for CS2n accesses is WRn (active Low). 1 The WRITE strobe for CS2n accesses is WR (active High). CS2n READ Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB8CFG2. Value Description 19 ALEHIGH RW 1 0 The READ strobe for CS2n accesses is RDn (active Low). 1 The READ strobe for CS2n accesses is RD (active High). CS2n ALE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB8CFG2. Value Description 18:8 reserved RO 0x00 0 The address latch strobe for CS2n accesses is ADVn (active Low). 1 The address latch strobe for CS2n accesses is ALE (active High). Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 915 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 7:6 WRWS RW 0x0 Description CS2n Write Wait States This field adds wait states to the data phase of CS2n accesses (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state adds 2 EPI clock cycles to the access time. The WRWSM bit in the EPIHB8TIME3 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB8CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active WRn is 2 EPI clocks 0x1 Active WRn is 4 EPI clocks 0x2 Active WRn is 6 EPI clocks 0x3 Active WRn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 5:4 RDWS RW 0x0 CS2n Read Wait States This field adds wait states to the data phase of CS2n accesses (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB8TIME3 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB8CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active RDn is 2 EPI clocks 0x1 Active RDn is 4 EPI clocks 0x2 Active RDn is 6 EPI clocks 0x3 Active RDn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 3:2 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 916 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1:0 MODE RW 0x0 Description CS2n Host Bus Sub-Mode This field determines which Host Bus 8 sub-mode to use for CS2n in multiple chip-select mode. Sub-mode use is determined by the connected external peripheral. See Table 11-8 on page 831 for information on how this bit field affects the operation of the EPI signals. Note: The CSBAUD bit must be set to enable this CS2n MODE field. If CSBAUD is clear, all chip-selects use the MODE configuration defined in the EPIHB8CFG register. Value Description 0x0 ADMUX – AD[7:0] Data and Address are muxed. 0x1 ADNONMUX – D[7:0] Data and address are separate. 0x2-0x3 reserved June 18, 2014 917 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 35: EPI Host-Bus 16 Configuration 3 (EPIHB16CFG3), offset 0x308 Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB16CFG3 to be valid, the MODE field must be 0x3. EPI Host-Bus 16 Configuration 3 (EPIHB16CFG3) Base 0x400D.0000 Offset 0x308 Type RW, reset 0x0008.0000 31 30 29 28 27 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 26 25 24 23 22 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 1 RW 0 10 9 8 7 6 5 4 3 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 reserved Type Reset WRWS RO 0 20 19 18 17 16 RDCRE BURST RW 0 RW 0 2 1 0 RO 0 RW 0 WRHIGH RDHIGH ALEHIGH WRCRE reserved Type Reset 21 RDWS reserved MODE RW 0 Bit/Field Name Type Reset Description 31:22 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 21 WRHIGH RW 0 CS2n WRITE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB16CFG2. Value Description 20 RDHIGH RW 0 0 The WRITE strobe for CS2n accesses is WRn (active Low). 1 The WRITE strobe for CS2n accesses is WR (active High). CS2n READ Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB16CFG2. Value Description 19 ALEHIGH RW 1 0 The READ strobe for CS2n accesses is RDn (active Low). 1 The READ strobe for CS2n accesses is RD (active High). CS2n ALE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB16CFG2. Value Description 0 The address latch strobe for CS2n accesses is ADVn (active Low). 1 The address latch strobe for CS2n accesses is ALE (active High). 918 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 18 WRCRE RW 0 Description CS2n PSRAM Configuration Register Write Used for PSRAM configuration registers. With WRCRE set, the next transaction by the EPI is a write of the CR bit field in the EPIHBPSRAM register to the configuration register (CR) of the PSRAM. The WRCRE bit self clears once the write-enabled CRE access is complete. Value Description 17 RDCRE RW 0 0 No Action. 1 Start CRE write transaction for CS2n. CS2n PSRAM Configuration Register Read Used for PSRAM configuration registers. With the RDCRE set, the next access is a read of the PSRAM's Configuration Register (CR). This bit self clears once the CRE access is complete. The address for the CRE access is located at EPIHBPSRAM[19:18]. The read data is returned on EPIHBPSRAM[15:0]. Value Description 16 BURST RW 0 0 No Action. 1 Start CRE read transaction for CS2n. CS2n Burst Mode Burst mode must be used with an ALE, which is configured by programming the CSCFG and CSCFGEXT fields in the EPIHB16CFG2 register. Burst mode must be used in ADMUX, which is set by the MODE field in EPIHB16CFG3. Note: Burst mode is optimized for word-length accesses. Value Description 15:8 reserved RO 0x00 0 Burst mode is disabled. 1 Burst mode is enabled for CS2n. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 919 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 7:6 WRWS RW 0x0 Description CS2n Write Wait States This field adds wait states to the data phase of CS2n accesses (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state adds 2 EPI clock cycles to the access time. The WRWSM bit in the EPIHB16TIME3 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the EPIHB16CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active WRn is 2 EPI clocks 0x1 Active WRn is 4 EPI clocks 0x2 Active WRn is 6 EPI clocks 0x3 Active WRn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 5:4 RDWS RW 0x0 CS2n Read Wait States This field adds wait states to the data phase of CS2n accesses (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB16TIME3 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB16CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active RDn is 2 EPI clocks 0x1 Active RDn is 4 EPI clocks 0x2 Active RDn is 6 EPI clocks 0x3 Active RDn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 3:2 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 920 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1:0 MODE RW 0x0 Description CS2n Host Bus Sub-Mode This field determines which Host Bus 16 sub-mode to use for CS2n in multiple chip select mode. Sub-mode use is determined by the connected external peripheral. See Table 11-9 on page 833 for information on how this bit field affects the operation of the EPI signals. Note: The CSBAUD bit must be set to enable this CS2n MODE field. If CSBAUD is clear, all chip-selects use the MODE configuration defined in the EPIHB16CFG register. Value Description 0x0 ADMUX – AD[15:0] Data and Address are muxed. 0x1 ADNONMUX – D[15:0] Data and address are separate. This mode is not practical in HB16 mode for normal peripherals because there are generally not enough address bits available. 0x2-0x3 reserved June 18, 2014 921 Texas Instruments-Production Data External Peripheral Interface (EPI) Register 36: EPI Host-Bus 8 Configuration 4 (EPIHB8CFG4), offset 0x30C Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB8CFG4 to be valid, the MODE field must be 0x2. EPI Host-Bus 8 Configuration 4 (EPIHB8CFG4) Base 0x400D.0000 Offset 0x30C Type RW, reset 0x0008.0000 31 30 29 28 27 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 26 25 24 23 22 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 1 RO 0 RO 0 RO 0 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RW 0 reserved Type Reset WRWS RO 0 20 19 18 WRHIGH RDHIGH ALEHIGH reserved Type Reset 21 Bit/Field Name Type Reset 31:22 reserved RO 0x0 21 WRHIGH RW 0 RDWS 17 16 reserved reserved MODE RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS3n WRITE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB8CFG2. Value Description 20 RDHIGH RW 0 0 The WRITE strobe for CS3n accesses is WRn (active Low). 1 The WRITE strobe for CS3n accesses is WR (active High). CS2n READ Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB8CFG2. Value Description 19 ALEHIGH RW 1 0 The READ strobe for CS3n accesses is RDn (active Low). 1 The READ strobe for CS3n accesses is RD (active High). CS3n ALE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB8CFG2 Value Description 18:8 reserved RO 0x00 0 The address latch strobe for CS3n accesses is ADVn (active Low). 1 The address latch strobe for CS3n accesses is ALE (active High). Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 922 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 7:6 WRWS RW 0x0 Description CS3n Write Wait States This field adds wait states to the data phase of CS3n accesses (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state adds 2 EPI clock cycles to the access time. The WRWSM bit in the EPIHB8TIME4 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is enabled in the EPIHB8CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active WRn is 2 EPI clocks 0x1 Active WRn is 4 EPI clocks 0x2 Active WRn is 6 EPI clocks 0x3 Active WRn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 5:4 RDWS RW 0x0 CS3n Read Wait States This field adds wait states to the data phase of CS3n accesses (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB8TIME4 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used when the CSBAUD bit is set in the EPIHB8CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active RDn is 2 EPI clocks 0x1 Active RDn is 4 EPI clocks 0x2 Active RDn is 6 EPI clocks 0x3 Active RDn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 3:2 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 923 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 1:0 MODE RW 0x0 Description CS3n Host Bus Sub-Mode This field determines which Host Bus 8 sub-mode to use for CS3n in multiple chip select mode. Sub-mode use is determined by the connected external peripheral. See Table 11-8 on page 831 for information on how this bit field affects the operation of the EPI signals. Note: The CSBAUD bit must be set to enable this CS3n MODE field. If CSBAUD is clear, all chip-selects use the MODE configuration defined in the EPIHB8CFG register. Value Description 0x0 ADMUX – AD[7:0] Data and Address are muxed. 0x1 ADNONMUX – D[7:0] Data and address are separate. 0x2-0x3 reserved 924 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 37: EPI Host-Bus 16 Configuration 4 (EPIHB16CFG4), offset 0x30C Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB16CFG4 to be valid, the MODE field must be 0x3. EPI Host-Bus 16 Configuration 4 (EPIHB16CFG4) Base 0x400D.0000 Offset 0x30C Type RW, reset 0x0008.0000 31 30 29 28 27 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 26 25 24 23 22 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 1 RW 0 10 9 8 7 6 5 4 3 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 reserved Type Reset WRWS RO 0 20 19 18 17 16 RDCRE BURST RW 0 RW 0 2 1 0 RO 0 RW 0 WRHIGH RDHIGH ALEHIGH WRCRE reserved Type Reset 21 RDWS reserved MODE RW 0 Bit/Field Name Type Reset Description 31:22 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 21 WRHIGH RW 0 CS3n WRITE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB16CFG2. Value Description 20 RDHIGH RW 0 0 The WRITE strobe for CS3n accesses is WRn (active Low). 1 The WRITE strobe for CS3n accesses is WR (active High). CS3n READ Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB16CFG2. Value Description 19 ALEHIGH RW 1 0 The READ strobe for CS3n accesses is RDn (active Low). 1 The READ strobe for CS3n accesses is RD (active High). CS3n ALE Strobe Polarity This field is used if the CSBAUD bit is enabled in EPIHB16CFG2. Value Description 0 The address latch strobe for CS3n accesses is ADVn (active Low). 1 The address latch strobe for CS3n accesses is ALE (active High). June 18, 2014 925 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 18 WRCRE RW 0 Description CS3n PSRAM Configuration Register Write Used for PSRAM configuration registers. With WRCRE set, the next transaction by the EPI will be a write of the CR bit field in the EPIHBPSRAM register to the configuration register (CR) of the PSRAM. The WRCRE bit will self clear once the write-enabled CRE access is complete. Value Description 17 RDCRE RW 0 0 No Action. 1 Start CRE write transaction for CS3n. CS3n PSRAM Configuration Register Read Used for PSRAM configuration registers. With the RDCRE set, the next access is a read of the PSRAM's Configuration Register (CR). This bit self clears once the CRE access is complete. The address for the CRE access is located at EPIHBPSRAM[19:18]. The read data is returned on EPIHBPSRAM[15:0]. Value Description 16 BURST RW 0 0 No Action. 1 Start CRE read transaction for CS3n. CS3n Burst Mode Burst mode must be used with an ALE, which is configured by programming the CSCFG and CSCFGEXT fields in the EPIHB16CFG2 register. Burst mode must be used in ADMUX, which is set by the MODE field in EPIHB16CFG4. Note: Burst mode is optimized for word-length accesses. Value Description 15:8 reserved RO 0x00 0 Burst mode is disabled. 1 Burst mode is enabled for CS3n. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 926 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 7:6 WRWS RW 0x0 Description CS3n Write Wait States This field adds wait states to the data phase of CS2n accesses (the address phase is not affected). The effect is to delay the rising edge of WRn (or the falling edge of WR). Each wait state adds 2 EPI clock cycles to the access time. The WRWSM bit in the EPIHB16TIME4 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used if the CSBAUD bit is set in the EPIHB16CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active WRn is 2 EPI clocks 0x1 Active WRn is 4 EPI clocks 0x2 Active WRn is 6 EPI clocks 0x3 Active WRn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 5:4 RDWS RW 0x0 CS3n Read Wait States This field adds wait states to the data phase of CS3n accesses (the address phase is not affected). The effect is to delay the rising edge of RDn/Oen (or the falling edge of RD). Each wait state adds 2 EPI clock cycles to the access time. The RDWSM bit in the EPIHB16TIME4 register can decrease the number of wait states by 1 EPI clock cycle for greater granularity. This field is used when the CSBAUD bit is set in the EPIHB16CFG2 register. This field is not applicable in BURST mode. Value Description 0x0 Active RDn is 2 EPI clocks 0x1 Active RDn is 4 EPI clocks 0x2 Active RDn is 6 EPI clocks 0x3 Active RDn is 8 EPI clocks This field is used in conjunction with the EPIBAUD2 register. 3:2 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 927 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 1:0 MODE RW 0x0 Description CS3n Host Bus Sub-Mode This field determines which Host Bus 16 sub-mode to use for CS3n in multiple chip select mode. Sub-mode use is determined by the connected external peripheral. See Table 11-9 on page 833 for information on how this bit field affects the operation of the EPI signals. Note: The CSBAUD bit must be set to enable this CS3n MODE field. If CSBAUD is clear, all chip-selects use the MODE configuration defined in the EPIHB16CFG register. Value Description 0x0 ADMUX – AD[15:0] Data and Address are muxed. 0x1 ADNONMUX – D[15:0] Data and address are separate. This mode is not practical in HB16 mode for normal peripherals because there are generally not enough address bits available. 0x2-0x3 reserved 928 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 38: EPI Host-Bus 8 Timing Extension (EPIHB8TIME), offset 0x310 Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB8TIME to be valid, the MODE field must be 0x2. EPI Host-Bus 8 Timing Extension (EPIHB8TIME) Base 0x400D.0000 Offset 0x310 Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 RW 0 23 22 21 20 RW 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 19 18 17 16 RO 0 RO 0 RO 1 RO 0 3 2 1 0 reserved reserved RO 0 WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS0n Input Ready Delay Value Description 23:14 reserved RO 0x008 13:12 CAPWIDTH RW 0x2 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS0n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 11:5 reserved RO 0x00 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 929 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 4 WRWSM RW 0 Description Write Wait State Minus One This bit is used with the WRWS field in EPIHB8CFG. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB8CFG register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB8CFG. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Read Wait State Minus One Use with RDWS field in the EPIHB8CFG register. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB8CFG. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB8CFG. 930 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 39: EPI Host-Bus 16 Timing Extension (EPIHB16TIME), offset 0x310 Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB16TIME to be valid, the MODE field must be 0x3. EPI Host-Bus 16 Timing Extension (EPIHB16TIME) Base 0x400D.0000 Offset 0x310 Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 RW 0 23 22 20 19 18 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 1 RW 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 21 reserved reserved RO 0 17 16 PSRAMSZ WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS0n Input Ready Delay Value Description 23:19 reserved RO 0x000 18:16 PSRAMSZ RW 0x2 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PSRAM Row Size Defines the row size for the PSRAM controlled by CS0n Value Description 0x0 No row size limitation 0x1 128 B 0x2 256 B 0x3 512 B 0x4 1024 B 0x5 2048 B 0x6 4096 B 0x7 8192 B June 18, 2014 931 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 15:14 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 13:12 CAPWIDTH RW 0x2 CS0n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 11:5 reserved RO 0x0 4 WRWSM RW 0 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Write Wait State Minus One This bit is used with the WRWS field in EPIHB16CFG. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB16CFG register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB16CFG. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Read Wait State Minus One Use with RDWS field in the EPIHB16CFG register. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB16CFG. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB16CFG. 932 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 40: EPI Host-Bus 8 Timing Extension (EPIHB8TIME2), offset 0x314 Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB8TIME2 to be valid, the MODE field must be 0x2. EPI Host-Bus 8 Timing Extension (EPIHB8TIME2) Base 0x400D.0000 Offset 0x314 Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 1 RO 0 RW 0 23 22 21 20 RW 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 reserved reserved RO 0 WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS1n Input Ready Delay Value Description 23:14 reserved RO 0x002 13:12 CAPWIDTH RW 0x2 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS1n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 11:5 reserved RO 0x00 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 933 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 4 WRWSM RW 0 Description CS1n Write Wait State Minus One This bit is used with the WRWS field in EPIHB8CFG2. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB8CFG2 register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB8CFG2. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS1n Read Wait State Minus One This field is used with RDWS field in EPIHB8CFG2. This bit is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB8CFG2. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB8CFG2. 934 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 41: EPI Host-Bus 16 Timing Extension (EPIHB16TIME2), offset 0x314 Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB16TIME2 to be valid, the MODE field must be 0x3. EPI Host-Bus 16 Timing Extension (EPIHB16TIME2) Base 0x400D.0000 Offset 0x314 Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 RW 0 23 22 20 19 18 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 1 RW 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 21 reserved reserved RO 0 17 16 PSRAMSZ WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS1n Input Ready Delay Value Description 23:19 reserved RO 0x000 18:16 PSRAMSZ RW 0x2 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PSRAM Row Size Defines the row size for the PSRAM controlled by CS1n Value Description 0x0 No row size limitation 0x1 128 B 0x2 256 B 0x3 512 B 0x4 1024 B 0x5 2048 B 0x6 4096 B 0x7 8192 B June 18, 2014 935 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 15:14 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 13:12 CAPWIDTH RW 0x2 CS1n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 11:5 reserved RO 0x00 4 WRWSM RW 0 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS1n Write Wait State Minus One This bit is used with the WRWS field in EPIHB16CFG2. This field is not applicable in BURST mode.. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB16CFG2 register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB16CFG2. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS1n Read Wait State Minus One This field is used with RDWS field in EPIHB16CFG2. This bit is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB16CFG2. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB16CFG2. 936 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 42: EPI Host-Bus 8 Timing Extension (EPIHB8TIME3), offset 0x318 Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB8TIME3 to be valid, the MODE field must be 0x2. EPI Host-Bus 8 Timing Extension (EPIHB8TIME3) Base 0x400D.0000 Offset 0x318 Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 1 RO 0 RW 0 23 22 21 20 RW 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 reserved reserved RO 0 WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS2n Input Ready Delay Value Description 23:14 reserved RO 0x002 13:12 CAPWIDTH RW 0x2 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS2n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 11:5 reserved RO 0x00 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 937 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset 4 WRWSM RW 0 Description CS2n Write Wait State Minus One This bit is used with the WRWS field in EPIHB8CFG3. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB8CFG3 register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB8CFG3. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS2n Read Wait State Minus One This field is used with RDWS field in EPIHB8CFG3. This bit is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB8CFG3. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB8CFG3. 938 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 43: EPI Host-Bus 16 Timing Extension (EPIHB16TIME3), offset 0x318 Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB16TIME3 to be valid, the MODE field must be 0x3. EPI Host-Bus 16 Timing Extension (EPIHB16TIME3) Base 0x400D.0000 Offset 0x318 Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 RW 0 23 22 20 19 18 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 1 RW 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 21 reserved reserved RO 0 17 16 PSRAMSZ WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS2n Input Ready Delay Value Description 23:19 reserved RO 0x000 18:16 PSRAMSZ RW 0x2 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PSRAM Row Size Defines the row size for the PSRAM controlled by CS2n Value Description 0x0 No row size limitation 0x1 128 B 0x2 256 B 0x3 512 B 0x4 1024 B 0x5 2048 B 0x6 4096 B 0x7 8192 B June 18, 2014 939 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 15:14 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 13:12 CAPWIDTH RW 0x2 CS2n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 11:5 reserved RO 0x00 4 WRWSM RW 0 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS2n Write Wait State Minus One This bit is used with the WRWS field in EPIHB16CFG3. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB16CFG3 register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB16CFG3. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS2n Read Wait State Minus One This field is used with RDWS field in EPIHB16CFG3. This bit is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB16CFG3. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB16CFG3. 940 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 44: EPI Host-Bus 8 Timing Extension (EPIHB8TIME4), offset 0x31C Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB8TIME4 to be valid, the MODE field must be 0x2. EPI Host-Bus 8 Timing Extension (EPIHB8TIME4) Base 0x400D.0000 Offset 0x31C Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 1 RO 0 RW 0 23 22 21 20 RW 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 reserved reserved RO 0 WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS3n Input Ready Delay Value Description 23:14 reserved RO 0x002 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Bits [18:16] have the same RTL implementation as the HB16TIMEn register, even though this is not used in HB8 mode. Thus, the reset value of 0x2 is carried over from the PSRAMSZ bits of HB16TIMEn. 13:12 CAPWIDTH RW 0x2 CS3n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved June 18, 2014 941 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 11:5 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 WRWSM RW 0 CS3n Write Wait State Minus One This bit is used with the WRWS field in EPIHB8CFG4. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB8CFG4 register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB8CFG4. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS3n Read Wait State Minus One This field is used with RDWS field in EPIHB8CFG4. This bit is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB8CFG4. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB8CFG4. 942 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 45: EPI Host-Bus 16 Timing Extension (EPIHB16TIME4), offset 0x31C Important: The MODE field in the EPICFG register determines which configuration is enabled. For EPIHB16TIME4 to be valid, the MODE field must be 0x3. EPI Host-Bus 16 Timing Extension (EPIHB16TIME4) Base 0x400D.0000 Offset 0x31C Type RW, reset 0x0002.2000 31 30 29 RO 0 RO 0 RO 0 15 14 13 28 27 26 25 RO 0 RO 0 RO 0 RW 0 12 11 10 9 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 RW 0 23 22 20 19 18 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 1 RW 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 IRDYDLY CAPWIDTH RW 1 24 21 reserved reserved RO 0 17 16 PSRAMSZ WRWSM RW 0 reserved RO 0 RO 0 RDWSM RO 0 RW 0 Bit/Field Name Type Reset Description 31:26 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25:24 IRDYDLY RW 0x0 CS3n Input Ready Delay Value Description 23:19 reserved RO 0x000 18:16 PSRAMSZ RW 0x2 0 reserved 1 Stall begins one EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 2 Stall begins two EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. 3 Stall begins three EPI clocks past iRDY low being sampled on the rising edge of EPIO clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PSRAM Row Size Defines the row size for the PSRAM controlled by CS3n Value Description 0x0 No row size limitation 0x1 128 B 0x2 256 B 0x3 512 B 0x4 1024 B 0x5 2048 B 0x6 4096 B 0x7 8192 B June 18, 2014 943 Texas Instruments-Production Data External Peripheral Interface (EPI) Bit/Field Name Type Reset Description 15:14 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 13:12 CAPWIDTH RW 0x2 CS3n Inter-transfer Capture Width Controls the delay between Host-Bus transfers. Value Description 11:5 reserved RO 0x00 4 WRWSM RW 0 0x0 Reserved 0x1 1 EPI clock. 0x2 2 EPI clock. 0x3 Reserved Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS3n Write Wait State Minus One This bit is used with the WRWS field in EPIHB16CFG4. This field is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the in WRWS field in EPIHB16CFG4 register. 1 Wait state value is now: WRWS - 1 WRWS field is programmed in EPIHB16CFG4. 3:1 reserved RO 0x0 0 RDWSM RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CS3n Read Wait State Minus One This field is used with RDWS field in EPIHB16CFG4. This bit is not applicable in BURST mode. Value Description 0 No change in the number of wait state clock cycles programmed in the RDWS field of EPIHB16CFG4. 1 Wait state value is now: RDWS - 1 RDWS field is programmed in EPIHB16CFG4. 944 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 46: EPI Host-Bus PSRAM (EPIHBPSRAM), offset 0x360 This register holds the PSRAM configuration register value. When the WRCRE bit in the EPIHB16CFGn register is set, all 21 bits of the EPIHBPSRAM register's CR value are written to the PSRAM's configuration register. When the RDCRE bit is set in the EPIHB16CFGn register, a read of the PSRAM's configuration register takes place and the value is written to bits[15:0] of the EPIHBPSRAM. Bits[20:16] will not contain any valid data. EPI Host-Bus PSRAM (EPIHBPSRAM) Base 0x400D.0000 Offset 0x360 Type RW, reset 0x0000.0000 31 30 29 28 27 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 RW 0 RW 0 RW 0 RW 0 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset CR CR Type Reset Bit/Field Name Type Reset Description 31:21 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 20:0 CR RW 0x000000 PSRAM Config Register During a configuration write, all 21 bits of the CR bit field are written to the PSRAM. During configuration reads, CR bits[15:0] of this register contain the configuration read of the PSRAM. CR[20:16] will not contain valid data. June 18, 2014 945 Texas Instruments-Production Data Cyclical Redundancy Check (CRC) 12 Cyclical Redundancy Check (CRC) The Cyclical Redundancy Check (CRC) computation module can be used for message transfer and safety system checks The following features are supported: ■ Support four major CRC forms: – CRC16-CCITT as used by CCITT/ITU X.25 – CRC16-IBM as used by USB and ANSI – CRC32-IEEE as used by IEEE802.3 and MPEG2 – CRC32C as used by G.Hn ■ Allows word and byte feed ■ Supports auto-initialization and manual initialization ■ Supports MSb and LSb ■ Supports CCITT post-processing ■ Can be fed by µDMA, Flash memory and code 12.1 Functional Description The following sections describe the features of CRC. 12.1.1 CRC Support The purpose of the CRC engine is to accelerate CRC and TCP checksum operation. The result of the CRC operation is a 32- and 16-bit signature which can be used to check the sanity of data. The required mode of operation is selected through the TYPE bit in the CRC Control (CRCCTRL) register, offset 0x400. A µDMA software channel can be used to burst data into the CRC module. CRCs are computed combinatorially in one clock. The CRC module contains all of the control registers to which the input context interfaces. Because CRC calculations are a single cycle, as soon as data is written to CRC Data Input (CRCDIN) register, the result of CRC/CSUM is updated in the CRC SEED/Context (CRCSEED) register, offset 0x410. The input data is computed by the selected CRC polynomial or CSUM. 12.1.1.1 CRC Checksum engine Software can offload the CRC and checksum task to the CRC checksum engine accelerator. The accelerator has registers that need to be programmed to initiate processing. These registers should be fed with data in order to calculate CRC/CSUM. Software should configure the µDMA channel for data movement through the DMA Channel Map Select n (DMACHMAPn) register in the μDMA module. Further µDMA configuration guidelines are available in the “Micro Direct Memory Access (μDMA)” on page 678. The starting seed for the CRC and checksum operation is programmed in the CRC SEED/Context (CRCSEED) register at offset 0x410. Depending on the encoding of the INIT field in the CRCCTRL register, the value of the SEED field can initialized to any one of the following: ■ A unique context value written to the CRCSEED register (INIT=0x0) 946 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ All 0s (INIT=0x2) ■ All 1s (INIT=0x3) Once the operation is done, software should read the result from the CRC Post Processing Result (CRCRSLTPP) register, offset 0x418, and a software channel μDMA interrupt should be used to identify completion. 12.1.1.2 Data Size The CRC module supports data being fed 32-bit words and 8 bits at a time and can dynamically switch back and forth. The data size is configured by programming the SIZE bit in the CRCCTRL register, offset 0x400. Because CRC is a division on a long stream of bits, the application must take into consideration the bit order. When processing message data that is read out by words, bit order is not an issue. For example, if the data value in the message is 0x12345678, the most significant eight byte is 0x12 (00010010 in binary). If the data is processed as bytes, 0x12, 0x34, 0x56, and 0x78 are copied into memory in that order and the word is stored as 0x78563412, where 0x12 is written as byte 0, 0x34 is written as byte 1, and so on. 12.1.1.3 Endian Configuration The following endian configuration is provided by the ENDIAN field in the CRCCTRL register: ■ Swap byte in half-word ■ Swap half word Input data width is four bytes, hence the configuration only affects the four-byte word. The ENDIAN bit field supports the following configurations, assuming the input word is {B3, B2, B1, B0} Table 12-1. Endian Configuration ENDIAN Encoding Definition Configuration 0x0 Configuration unchanged. {B3, B2, B1, B0} 0x1 Bytes are swapped in half-words but half-words are not swapped {B2, B3, B0, B1} 0x2 Half-words are swapped but bytes are not swapped in half-word. {B1, B0, B3, B2} 0x3 Bytes are swapped in half-words and half-words are swapped. {B0, B1, B2, B3} Bit reversal is supported by the BR bit in the CRCCTRL register. The bit reversal operation works in tandem with endian control. For example, the above table with the BR option set would look like this: Table 12-2. Endian Configuration with Bit Reversal ENDIAN Encoding 0x0 Initial Endian Configuration Configuration unchanged. Configuration with Bit Reversal (BR = 1) B3[24:31],B2[16:23],B1[8:15],B0[0:7] {B3[31:24], B2[23:16] , B1[15:8], B0[7:0]} 0x1 Bytes are swapped in half-words but half-words are not swapped B2[16:23],B3[24:31],B0[0:7],B1[8:15] {B2[23:16], B3[31:24], B0[7:0], B1[15:8]} June 18, 2014 947 Texas Instruments-Production Data Cyclical Redundancy Check (CRC) Table 12-2. Endian Configuration with Bit Reversal (continued) ENDIAN Encoding 0x2 Initial Endian Configuration Half-words are swapped but bytes are not swapped in half-word. Configuration with Bit Reversal (BR = 1) B1[8:15],B0[0:7],B3[24:31],B2[16:23] {B1[15:8], B0[7:0], B3[31:24], B2[23:16]} 0x3 Bytes are swapped in half-words and half-words are swapped B0[0:7],B1[8:15],B2[16:23],B3[24:31] {B0[7:0], B1[15:8], B2[23:16], B3[31:24]} 12.2 Initialization and Configuration The following describes the initialization and configuration procedures of the CRC module. 12.2.1 CRC Initialization and Configuration The CRC engine works in push through mode, which means it works on streaming data. This section describes the steps for initializing the CRC module: 1. Enable the CRC by setting the R0 bit in the CRC Module (RCGCCM) register, System Control offset 0x674. 2. Configure the desired CRC data size, bit order, endian configuration and CRC type by programming the CRC Control (CRCCTRL) register, offset 0x400. 3. If the CRC value has not been initialized to all 0s or all 1s using the INIT field in the CRCCTRL register, program the initial value in the CRC SEED/Context (CRCSEED) register, offset 0x410. 4. Repeatedly write the DATAIN field in the CRC Data Input (CRCDIN) register, offset 0x414. If the SIZE bit in the CRCCTRL register is set to select byte, the CRC engine operates in byte mode and only the least significant byte is used for CRC calculation. 5. When CRC is finished, read the CRCSEED register for the final result. If using post-processing, the raw CRC result is stored in the CRCSEED register and the final, post-processed result can be read from the CRC Post-Processing Result (CRCRSLTPP) register, offset 0x418. Post-processing options are selectable through the OBR and OLNV bits of the CRCCTRL register. Alternatively a software µDMA channel can be configured to copy data from the source into the CRCDIN register. When configuring the µDMA, the destination should be configured to not increment. For more information on how to configure the µDMA, refer to “Micro Direct Memory Access (μDMA)” on page 678. 12.2.1.1 Data Endian Convention for the CRC Engine If the input stream is expressed as a byte stream, Din, where Din = {D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D12, D13, D14, D15, D16.....}, then data should be fed to the CRC engine as follows: ■ If operating in Byte mode, the CRCDIN register should be written in the following order: 1. {00, 00, 00, D0} 2. {00, 00, 00, D1} 3. {00, 00, 00, D2} 948 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 4. {00, 00, 00, D3} 5. {00, 00, 00, D4} 6. {00, 00, 00, D5} 7. {00, 00, 00, D6} 8. ...... 9. ..... ■ If operating in word mode, the CRCDIN register should be written in the following order: 1. {D3, D2, D1, D0} 2. {D7, D6, D5, D4} 3. {D11, D10, D9, D8} 4. ...... 5. ...... 12.3 Register Map Table 12-3 on page 949 lists the CRC Module registers. The offset listed is a hexadecimal increment to the register's address, relative to the base address 0x4403.0000. Table 12-3. CCM Register Map Type Reset Description See page CRCCTRL RW 0x0000.0000 CRC Control 950 0x410 CRCSEED RW 0x0000.0000 CRC SEED/Context 952 0x414 CRCDIN RW 0x0000.0000 CRC Data Input 953 0x418 CRCRSLTPP RO 0x0000.0000 CRC Post Processing Result 954 Offset Name 0x400 12.4 CRC Module Register Descriptions This section lists and describes the CRC registers, in numerical order by address offset. Note: The CRC module can only be accessed through privileged mode. If the µDMA is used for CRC transfers, then the µDMA's DMA Channel Control (DMACHCTL) register also needs to be programmed to allow for privileged accesses. June 18, 2014 949 Texas Instruments-Production Data Cyclical Redundancy Check (CRC) Register 1: CRC Control (CRCCTRL), offset 0x400 The CRC Control (CRCCTRL) register is used to configure control of the CRC. CRC Control (CRCCTRL) Base 0x4403.0000 Offset 0x400 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RESINV RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 OBR BR reserved RW 0 RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 INIT RW 0 SIZE RW 0 RW 0 reserved RO 0 RO 0 Bit/Field Name Type Reset 31:15 reserved RO 0x0000 14:13 INIT RW 0x0 ENDIAN RW 0 TYPE Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. CRC Initialization Determines initialization value of CRC. This field is self-clearing. With the first write to the CRC Data Input (CRCDIN) register, this value clears to zero and remains zero for the rest of the operation unless written again. Value Description 12 SIZE RW 0 0x0 Use the CRCSEED register context as the starting value 0x1 reserved 0x2 Initialize to all '0s' 0x3 Initialize to all '1s' Input Data Size Value Description 11:10 reserved RO 0x0 9 RESINV RW 0 0 32-bit (word) 1 8-bit (byte) Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Result Inverse Enable Value Description 0 No effect 1 Invert the result bits before storing in the CRCRSLTPP register. 950 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 8 OBR RW 0 Description Output Reverse Enable Refer to Table 12-2 on page 947 for more information regarding bit reversal. Value Description 7 BR RW 0 0 No change to result. 1 Bit reverse the output result byte before storing to CRCRSLTPP register. The reversal is applied to all bytes in a word. Bit reverse enable Refer to Table 12-2 on page 947 for more information regarding bit reversal. Value Description 0 No change to result. 1 Bit reverse the input byte for all bytes in a word. 6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5:4 ENDIAN RW 0 Endian Control This field is used to program the endian configuration. The encodings below are with respect to an input word = (B3, B2, B1, B0) Refer to Table 12-1 on page 947 for more information regarding endian configuration and control. Value Description 3:0 TYPE RW 0 0x0 Configuration unchanged. (B3, B2, B1, B0) 0x1 Bytes are swapped in half-words but half-words are not swapped (B2, B3, B0, B1) 0x2 Half-words are swapped but bytes are not swapped in half-word. (B1, B0, B3, B2) 0x3 Bytes are swapped in half-words and half-words are swapped. (B0, B1, B2, B3) Operation Type The TYPE value in the CRCCTRL register should be exclusive. Value Description 0x0 Polynomial 0x8005 0x1 Polynomial 0x1021 0x2 Polynomial 0x4C11DB7 0x3 Polynomial 0x1EDC6F41 0x4-0x7 reserved 0x8 TCP checksum 0x9-0xF reserved June 18, 2014 951 Texas Instruments-Production Data Cyclical Redundancy Check (CRC) Register 2: CRC SEED/Context (CRCSEED), offset 0x410 The CRC SEED/Context (CRCSEED) register is initially written with one of the following three values depending on the encoding of the INIT field in the CRCCTRL register: ■ The context value written to the CRCSEED register. This encoding is for SEED values from a previous CRC calculation or a specific protocol. (INIT=0x0) ■ 0x0000.0000 (INIT=0x2) ■ 0x1111.1111 (INIT=0x3) CRC SEED/Context (CRCSEED) Base 0x4403.0000 Offset 0x410 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 SEED Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 SEED Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type 31:0 SEED RW RW 0 Reset RW 0 Description 0x0000.0000 SEED/Context Value This register contains the starting seed of the CRC and checksum operation. This register also holds the latest result of CRC or checksum operation. 952 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: CRC Data Input (CRCDIN), offset 0x414 The application or µDMA writes the CRC Data Input (CRCDIN) register with the next byte or word to compute. CRC Data Input (CRCDIN) Base 0x4403.0000 Offset 0x414 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 DATAIN Type Reset DATAIN Type Reset Bit/Field Name Type 31:0 DATAIN RW Reset Description 0x0000.0000 Data Input This register contains the input data value for the CRC or checksum operation. June 18, 2014 953 Texas Instruments-Production Data Cyclical Redundancy Check (CRC) Register 4: CRC Post Processing Result (CRCRSLTPP), offset 0x418 This register contains the post-processed CRC result as configured by the CRCCTRL register. CRC Post Processing Result (CRCRSLTPP) Base 0x4403.0000 Offset 0x418 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RSLTPP Type Reset RSLTPP Type Reset Bit/Field Name Type 31:0 RSLTPP RO Reset Description 0x0000.0000 Post Processing Result This register contains the post-processed CRC result. 954 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 13 General-Purpose Timers Programmable timers can be used to count or time external events that drive the Timer input pins. The TM4C1294NCPDT General-Purpose Timer Module (GPTM) contains 16/32-bit GPTM blocks. Each 16/32-bit GPTM block provides two 16-bit timers/counters (referred to as Timer A and Timer B) that can be configured to operate independently as timers or event counters, or concatenated to operate as one 32-bit timer or one 32-bit Real-Time Clock (RTC). Timers can also be used to trigger μDMA transfers. In addition, timers can be used to trigger analog-to-digital conversions (ADC). The ADC trigger signals from all of the general-purpose timers are ORed together before reaching the ADC module, so only one timer should be used to trigger ADC events. The GPT Module is one timing resource available on the Tiva™ C Series microcontrollers. Other timer resources include the System Timer (SysTick) (see 135) and the PWM timer in the PWM module (see “PWM Timer” on page 1672). The General-Purpose Timer Module (GPTM) contains eight 16/32-bit GPTM blocks with the following functional options: ■ Operating modes: – 16- or 32-bit programmable one-shot timer – 16- or 32-bit programmable periodic timer – 16-bit general-purpose timer with an 8-bit prescaler – 32-bit Real-Time Clock (RTC) when using an external 32.768-KHz clock as the input – 16-bit input-edge count- or time-capture modes with an 8-bit prescaler – 16-bit PWM mode with an 8-bit prescaler and software-programmable output inversion of the PWM signal – The System Clock or a global Alternate Clock (ALTCLK) resource can be used as timer clock source. The global ALTCLK can be: • PIOSC • Hibernation Module Real-time clock output (RTCOSC) • Low-frequency internal oscillator (LFIOSC) ■ Count up or down ■ Twelve 16/32-bit Capture Compare PWM pins (CCP) ■ Daisy chaining of timer modules to allow a single timer to initiate multiple timing events ■ Timer synchronization allows selected timers to start counting on the same clock cycle ■ ADC event trigger ■ User-enabled stalling when the microcontroller asserts CPU Halt flag during debug (excluding RTC mode) June 18, 2014 955 Texas Instruments-Production Data General-Purpose Timers ■ Ability to determine the elapsed time between the assertion of the timer interrupt and entry into the interrupt service routine ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Dedicated channel for each timer – Burst request generated on timer interrupt 13.1 Block Diagram In the block diagram, the specific Capture Compare PWM (CCP) pins available depend on the TM4C1294NCPDT device. See Table 13-1 on page 956 for the available CCP pins and their timer assignments. Figure 13-1. GPTM Module Block Diagram 0xFFFF.FFFF 0x0000.0000 0xFFFF 0x0000 Timer A Control Timer A Free-Running Output Value Configuration / Interrupt Timer A Interrupt Timer B Interrupt GPTMCFG GPTMCTL GPTMSYNC GPTMIMR GPTMRIS GPTMMIS GPTMICR GPTMDMAEV GPTMADCEV GPTMPP GPTMCC Timer B Free-Running Output Value GPTMTAPS GPTMTAPMR GPTMTAPR GPTMTAMATCHR GPTMTAILR GPTMTAMR (Up Counter Modes, 32-/64-bit) (Down Counter Modes, 32-/64-bit) (Up Counter Modes, 16-/32-bit) (Down Counter Modes, 16-32-bit) TA Comparator Clk/Edge Detect GPTMTAR GPTMTAV 32 kHz or Even CCP Pin Timer A RTC Control GPTMRTCPD Timer B GPTMTBMR GPTMTBILR GPTMTBMATCHR GPTMTBPR GPTMTBPMR GPTMTBPS GPTMTBV GPTMTBR Clk/Edge Detect Odd CCP Pin TB Comparator Timer B Control 0xFFFF.FFFF 0x0000.0000 0xFFFF 0x0000 (Up Counter Modes, 32-/64-bit) (Down Counter Modes, 32-/64-bit) (Up Counter Modes, 16-/32-bit) (Down Counter Modes, 16-32-bit) Table 13-1. Available CCP Pins Timer 16/32-Bit Timer 0 16/32-Bit Timer 1 16/32-Bit Timer 2 Up/Down Counter Even CCP Pin Odd CCP Pin Timer A T0CCP0 - Timer B - T0CCP1 Timer A T1CCP0 - Timer B - T1CCP1 Timer A T2CCP0 - Timer B - T2CCP1 956 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 13-1. Available CCP Pins (continued) Timer 16/32-Bit Timer 3 16/32-Bit Timer 4 16/32-Bit Timer 5 16/32-Bit Timer 6 16/32-Bit Timer 7 13.2 Up/Down Counter Even CCP Pin Odd CCP Pin Timer A T3CCP0 - Timer B - T3CCP1 Timer A T4CCP0 - Timer B - T4CCP1 Timer A T5CCP0 - Timer B - T5CCP1 Timer A T6CCP0 - Timer B - T6CCP1 Timer A T7CCP0 - Timer B - T7CCP1 Signal Description The following table lists the external signals of the GP Timer module and describes the function of each. The GP Timer signals are alternate functions for some GPIO signals and default to be GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible GPIO pin placements for these GP Timer signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the GP Timer function. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the GP Timer signal to the specified GPIO port pin. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Table 13-2. General-Purpose Timers Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description T0CCP0 1 33 85 PD0 (3) PA0 (3) PL4 (3) I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 0. T0CCP1 2 34 86 PD1 (3) PA1 (3) PL5 (3) I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 1. T1CCP0 3 35 94 PD2 (3) PA2 (3) PL6 (3) I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 0. T1CCP1 4 36 93 PD3 (3) PA3 (3) PL7 (3) I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 1. T2CCP0 37 78 PA4 (3) PM0 (3) I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 0. T2CCP1 38 77 PA5 (3) PM1 (3) I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 1. T3CCP0 40 76 125 PA6 (3) PM2 (3) PD4 (3) I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 0. T3CCP1 41 75 126 PA7 (3) PM3 (3) PD5 (3) I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 1. June 18, 2014 957 Texas Instruments-Production Data General-Purpose Timers Table 13-2. General-Purpose Timers Signals (128TQFP) (continued) Pin Name 13.3 Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description T4CCP0 74 95 127 PM4 (3) PB0 (3) PD6 (3) I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 0. T4CCP1 73 96 128 PM5 (3) PB1 (3) PD7 (3) I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 1. T5CCP0 72 91 PM6 (3) PB2 (3) I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 0. T5CCP1 71 92 PM7 (3) PB3 (3) I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 1. Functional Description The main components of each GPTM block are two free-running up/down counters (referred to as Timer A and Timer B), two prescaler registers, two match registers, two prescaler match registers, two shadow registers, and two load/initialization registers and their associated control functions. The exact functionality of each GPTM is controlled by software and configured through the register interface. Timer A and Timer B can be used individually, in which case they have a 16-bit counting range for the 16/32-bit GPTM blocks. In addition, Timer A and Timer B can be concatenated to provide a 32-bit counting range for the 16/32-bit GPTM blocks. Note that the prescaler can only be used when the timers are used individually. The available modes for each GPTM block are shown in Table 13-3 on page 958. Note that when counting down in one-shot or periodic modes, the prescaler acts as a true prescaler and contains the least-significant bits of the count. When counting up in one-shot or periodic modes, the prescaler acts as a timer extension and holds the most-significant bits of the count. In input edge count, input edge time and PWM mode, the prescaler always acts as a timer extension, regardless of the count direction. Table 13-3. General-Purpose Timer Capabilities Mode One-shot Periodic a Timer Use Count Direction Counter Size Prescaler Size Individual Up or Down 16-bit Concatenated Up or Down 32-bit - Individual Up or Down 16-bit 8-bit 8-bit Concatenated Up or Down 32-bit - RTC Concatenated Up 32-bit - Edge Count Individual Up or Down 16-bit 8-bit Edge Time Individual Up or Down 16-bit 8-bit PWM Individual Down 16-bit 8-bit a. The prescaler is only available when the timers are used individually Software configures the GPTM using the GPTM Configuration (GPTMCFG) register (see page 976), the GPTM Timer A Mode (GPTMTAMR) register (see page 977), and the GPTM Timer B Mode (GPTMTBMR) register (see page 982). When in one of the concatenated modes, Timer A and Timer B can only operate in one mode. However, when configured in an individual mode, Timer A and Timer B can be independently configured in any combination of the individual modes. 958 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 13.3.1 GPTM Reset Conditions After reset has been applied to the GPTM module, the module is in an inactive state, and all control registers are cleared and in their default states. Counters Timer A and Timer B are initialized to all 1s, along with their corresponding registers: ■ Load Registers: – GPTM Timer A Interval Load (GPTMTAILR) register (see page 1004) – GPTM Timer B Interval Load (GPTMTBILR) register (see page 1005) ■ Shadow Registers: – GPTM Timer A Value (GPTMTAV) register (see page 1014) – GPTM Timer B Value (GPTMTBV) register (see page 1015) The following prescale counters are initialized to all 0s: ■ GPTM Timer A Prescale (GPTMTAPR) register (see page 1008) ■ GPTM Timer B Prescale (GPTMTBPR) register (see page 1009) ■ GPTM Timer A Prescale Snapshot (GPTMTAPS) register (see page 1017) ■ GPTM Timer B Prescale Snapshot (GPTMTBPS) register (see page 1018) 13.3.2 Timer Clock Source The general purpose timer has the capability of being clocked by either the system clock or an alternate clock source. By setting the ALTCLK bit in the GPTM Clock Configuration (GPTMCC) register, offset 0xFC8, software can selects an alternate clock source as programmed in the Alternate Clock Configuration (ALTCLKCFG) register, offset 0x138 in the System Control Module. The alternate clock source options available are PIOSC, RTCOSC and LFIOSC. Refer to “System Control” on page 220 for additional information. Note: When the ALTCLK bit is set in the GPTMCC register to enable using the alternate clock source, the synchronization imposes restrictions on the starting count value (down-count), terminal value (up-count) and the match value. This restriction applies to all modes of operation. Each event must be spaced by 4 Timer (ALTCLK) clock periods + 2 system clock periods. If some events do not meet this requirement, then it is possible that the timer block may need to be reset for correct functionality to be restored. Example: ALTCLK= TPIOSC = 62.5ns (16Mhz Trimmed) Thclk = 1us (1Mhz) 4*62.5ns + 2*1us = 2.25us 2.25us/62.5ns = 36 or 0x23 The minimum values for the periodic or one-shot with a match interrupt enabled are: GPTMTAMATCHR = 0x23 GPTMTAILR = 0x46 13.3.3 Timer Modes This section describes the operation of the various timer modes. When using Timer A and Timer B in concatenated mode, only the Timer A control and status bits must be used; there is no need to use Timer B control and status bits. The GPTM is placed into individual/split mode by writing a value June 18, 2014 959 Texas Instruments-Production Data General-Purpose Timers of 0x4 to the GPTM Configuration (GPTMCFG) register (see page 976). In the following sections, the variable "n" is used in bit field and register names to imply either a Timer A function or a Timer B function. Throughout this section, the timeout event in down-count mode is 0x0 and in up-count mode is the value in the GPTM Timer n Interval Load (GPTMTnILR) and the optional GPTM Timer n Prescale (GPTMTnPR) registers, with the exception of RTC mode. 13.3.3.1 One-Shot/Periodic Timer Mode The selection of one-shot or periodic mode is determined by the value written to the TnMR field of the GPTM Timer n Mode (GPTMTnMR) register (see page 977). The timer is configured to count up or down using the TnCDIR bit in the GPTMTnMR register. When software sets the TnEN bit in the GPTM Control (GPTMCTL) register (see page 986), the timer begins counting up from 0x0 or down from its preloaded value. Alternatively, if the TnWOT bit is set in the GPTMTnMR register, once the TnEN bit is set, the timer waits for a trigger to begin counting (see “Wait-for-Trigger Mode” on page 968). Table 13-4 on page 960 shows the values that are loaded into the timer registers when the timer is enabled. Table 13-4. Counter Values When the Timer is Enabled in Periodic or One-Shot Modes Register Count Down Mode Count Up Mode GPTMTnR GPTMTnILR 0x0 GPTMTnV GPTMTnILR in concatenated mode; GPTMTnPR in combination with GPTMTnILR in individual mode 0x0 GPTMTnPS GPTMTnPR in individual mode; not available in concatenated mode 0x0 in individual mode; not available in concatenated mode When the timer is counting down and it reaches the timeout event (0x0), the timer reloads its start value from the GPTMTnILR and the GPTMTnPR registers on the next cycle. When the timer is counting up and it reaches the timeout event (the value in the GPTMTnILR and the optional GPTMTnPR registers), the timer reloads with 0x0. If configured to be a one-shot timer, the timer stops counting and clears the TnEN bit in the GPTMCTL register. If configured as a periodic timer, the timer starts counting again on the next cycle. In periodic, snap-shot mode (TnMR field is 0x2 and the TnSNAPS bit is set in the GPTMTnMR register), the value of the timer at the time-out event is loaded into the GPTMTnR register and the value of the prescaler is loaded into the GPTMTnPS register. The free-running counter value is shown in the GPTMTnV register. In this manner, software can determine the time elapsed from the interrupt assertion to the ISR entry by examining the snapshot values and the current value of the free-running timer. Snapshot mode is not available when the timer is configured in one-shot mode. In addition to reloading the count value, the GPTM can generate interrupts, CCP outputs and triggers when it reaches the time-out event. The GPTM sets the TnTORIS bit in the GPTM Raw Interrupt Status (GPTMRIS) register (see page 996), and holds it until it is cleared by writing the GPTM Interrupt Clear (GPTMICR) register (see page 1002). If the time-out interrupt is enabled in the GPTM Interrupt Mask (GPTMIMR) register (see page 993), the GPTM also sets the TnTOMIS bit in the GPTM Masked Interrupt Status (GPTMMIS) register (see page 999). The time-out interrupt can be disabled entirely by setting the TnCINTD bit in the GPTM Timer n Mode (GPTMTnMR) register. In this case, the TnTORIS bit does not even set in the GPTMRIS register. By setting the TnMIE bit in the GPTMTnMR register, an interrupt condition can also be generated when the Timer value equals the value loaded into the GPTM Timer n Match (GPTMTnMATCHR) and GPTM Timer n Prescale Match (GPTMTnPMR) registers. This interrupt has the same status, masking, and clearing functions as the time-out interrupt, but uses the match interrupt bits instead (for example, the raw interrupt status is monitored via TnMRIS bit in the GPTM Raw Interrupt Status 960 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller (GPTMRIS) register). Note that the interrupt status bits are not updated by the hardware unless the TnMIE bit in the GPTMTnMR register is set, which is different than the behavior for the time-out interrupt. The ADC trigger is enabled by setting the TnOTE bit in GPTMCTL and the event that activates the ADC is configured in the GPTM ADC Event (GPTMADCEV) register. The μDMA trigger is enabled by configuring and enabling the appropriate μDMA channel as well as the type of trigger enable in the GPTM DMA Event (GPTMDMAEV) register. See “Channel Configuration” on page 683. The TCACT field of the GPTM Timer n Mode (GPTMTnMR) register can be configured to clear, set or toggle an output on a time-out event. If software updates the GPTMTnILR or the GPTMTnPR register while the counter is counting down, the counter loads the new value on the next clock cycle and continues counting from the new value if the TnILD bit in the GPTMTnMR register is clear. If the TnILD bit is set, the counter loads the new value after the next timeout. If software updates the GPTMTnILR or the GPTMTnPR register while the counter is counting up, the timeout event is changed on the next cycle to the new value. If software updates the GPTM Timer n Value (GPTMTnV) register while the counter is counting up or down, the counter loads the new value on the next clock cycle and continues counting from the new value. If software updates the GPTMTnMATCHR or the GPTMTnPMR registers, the new values are reflected on the next clock cycle if the TnMRSU bit in the GPTMTnMR register is clear. If the TnMRSU bit is set, the new value will not take effect until the next timeout. If the TnSTALL bit in the GPTMCTL register is set and the RTCEN bit is not set in the GPTMCTL register, the timer freezes counting while the processor is halted by the debugger. The timer resumes counting when the processor resumes execution. If the RTCEN bit is set, it prevents the TnSTALL bit from freezing the count when the processor is halted by the debugger. The following table shows a variety of configurations for a 16-bit free-running timer while using the prescaler. All values assume a 120-MHz clock with Tc=8.33 ns (clock period). The prescaler can only be used when a 16/32-bit timer is configured in 16-bit mode. Table 13-5. 16-Bit Timer With Prescaler Configurations a Prescale (8-bit value) # of Timer Clocks (Tc) Max Time Units 00000000 1 0.548258 ms 00000001 2 1.096517 ms 00000010 3 1.644775 ms ------------ -- -- -- 11111101 254 139.2576 ms 11111110 255 139.8059 ms 11111111 256 140.3541 ms a. Tc is the clock period. Timer Compare Action Mode The timer compare mode is an extension to the GPTM's existing one-shot and periodic modes. This mode can be used when an application requires a pin change state at some time in the future, regardless of the processor state. The compare mode does not operate when the PWM mode is active and is mutually exclusive to the PWM mode. The compare mode is enabled when the TAMR field is set to 0x1 or 0x2 (one-shot or periodic), the TnAMS bit is 0 (capture or compare mode) and the TCACT field is nonzero in the GPTM Timer n Mode (GPTMTnMR) register. Depending on the TCACT encoding, the timer can perform a set, clear or toggle on the corresponding CCPn pin when a timer match occurs. In 16-bit mode, the corresponding CCP pin can have an action applied, but when operating in 32-bit mode, the action can only be applied to the even CCP pin. June 18, 2014 961 Texas Instruments-Production Data General-Purpose Timers The TCACT field can be changed while the GPTM is enabled to generate different combinations of actions. For example, during a periodic event, encodings TCACT = 0x6 or 0x7 can be used to force the initial state of the CCPn pin before the first interrupt and following that, TCACT=0x2 and TCACT=0x3 can be used (alternately) to change the sense of the pin for the subsequent toggle, while possible changing load value for the next period. The time-out interrupts used for one-shot and periodic modes are used in the compare action modes. Thus, the TnTORIS bits in the GPTMRIS register are triggered if the appropriate mask bits are set in the GPTMIM register. 13.3.3.2 Real-Time Clock Timer Mode In Real-Time Clock (RTC) mode, the concatenated versions of the Timer A and Timer B registers are configured as an up-counter. When RTC mode is selected for the first time after reset, the counter is loaded with a value of 0x1. All subsequent load values must be written to the GPTM Timer n Interval Load (GPTMTnILR) registers (see page 1004). If the GPTMTnILR register is loaded with a new value, the counter begins counting at that value and rolls over at the fixed value of 0xFFFFFFFF. Table 13-6 on page 962 shows the values that are loaded into the timer registers when the timer is enabled. Table 13-6. Counter Values When the Timer is Enabled in RTC Mode Register Count Down Mode Count Up Mode GPTMTnR Not available 0x1 GPTMTnV Not available 0x1 GPTMTnPS Not available Not available The input clock on a CCP0 input is required to be 32.768 KHz in RTC mode. The clock signal is then divided down to a 1-Hz rate and is passed along to the input of the counter. When software writes the TAEN bit in the GPTMCTL register, the counter starts counting up from its preloaded value of 0x1. When the current count value matches the preloaded value in the GPTMTnMATCHR registers, the GPTM asserts the RTCRIS bit in GPTMRIS and continues counting until either a hardware reset, or it is disabled by software (clearing the TAEN bit). When the timer value reaches the terminal count, the timer rolls over and continues counting up from 0x0. If the RTC interrupt is enabled in GPTMIMR, the GPTM also sets the RTCMIS bit in GPTMMIS and generates a controller interrupt. The status flags are cleared by writing the RTCCINT bit in GPTMICR. In this mode, the GPTMTnR and GPTMTnV registers always have the same value. In addition to generating interrupts, the RTC can generate a μDMA trigger. The μDMA trigger is enabled by configuring and enabling the appropriate μDMA channel as well as the type of trigger enable in the GPTM DMA Event (GPTMDMAEV) register. See “Channel Configuration” on page 683. 13.3.3.3 Input Edge-Count Mode Note: For rising-edge detection, the input signal must be High for at least two clock periods following the rising edge. Similarly, for falling-edge detection, the input signal must be Low for at least two clock periods following the falling edge. Based on this criteria, the maximum input frequency for edge detection is 1/4 of the frequency. In Edge-Count mode, the timer is configured as a 24-bit up- or down-counter including the optional prescaler with the upper count value stored in the GPTM Timer n Prescale (GPTMTnPR) register and the lower bits in the GPTMTnR register. In this mode, the timer is capable of capturing three types of events: rising edge, falling edge, or both. To place the timer in Edge-Count mode, the TnCMR bit of the GPTMTnMR register must be cleared. The type of edge that the timer counts is 962 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller determined by the TnEVENT fields of the GPTMCTL register. During initialization in down-count mode, the GPTMTnMATCHR and GPTMTnPMR registers are configured so that the difference between the value in the GPTMTnILR and GPTMTnPR registers and the GPTMTnMATCHR and GPTMTnPMR registers equals the number of edge events that must be counted. In up-count mode, the timer counts from 0x0 to the value in the GPTMTnMATCHR and GPTMTnPMR registers. Note that when executing an up-count, that the value of GPTMTnPR and GPTMTnILR must be greater than the value of GPTMTnPMR and GPTMTnMATCHR. Table 13-7 on page 963 shows the values that are loaded into the timer registers when the timer is enabled. Table 13-7. Counter Values When the Timer is Enabled in Input Edge-Count Mode Register Count Down Mode Count Up Mode GPTMTnR GPTMTnPR in combination with GPTMTnILR 0x0 GPTMTnV GPTMTnPR in combination with GPTMTnILR 0x0 When software writes the TnEN bit in the GPTM Control (GPTMCTL) register, the timer is enabled for event capture. Each input event on the CCP pin decrements or increments the counter by 1 until the event count matches GPTMTnMATCHR and GPTMTnPMR. When the counts match, the GPTM asserts the CnMRIS bit in the GPTM Raw Interrupt Status (GPTMRIS) register, and holds it until it is cleared by writing the GPTM Interrupt Clear (GPTMICR) register. If the capture mode match interrupt is enabled in the GPTM Interrupt Mask (GPTMIMR) register, the GPTM also sets the CnMMIS bit in the GPTM Masked Interrupt Status (GPTMMIS) register. In up-count mode, the current count of the input events is held in both the GPTMTnR and GPTMTnV registers. In down-count mode, the current count of the input events can be obtained by subtracting the GPTMTnR or GPTMTnV from the value made up of the GPTMTnPR and GPTMTnILR register combination. In addition to generating interrupts, an ADC and/or a μDMA trigger can be generated. The ADC trigger is enabled by setting the TnOTE bit in GPTMCTL and the event that activates the ADC is configured in the GPTM ADC Event (GPTMADCEV) register. The μDMA trigger is enabled by configuring and enabling the appropriate μDMA channel as well as the type of trigger enable in the GPTM DMA Event (GPTMDMAEV) register. See “Channel Configuration” on page 683. After the match value is reached in down-count mode, the counter is then reloaded using the value in GPTMTnILR and GPTMTnPR registers, and stopped because the GPTM automatically clears the TnEN bit in the GPTMCTL register. Once the event count has been reached, all further events are ignored until TnEN is re-enabled by software. In up-count mode, the timer is reloaded with 0x0 and continues counting. Figure 13-2 on page 964 shows how Input Edge-Count mode works. In this case, the timer start value is set to GPTMTnILR =0x000A and the match value is set to GPTMTnMATCHR =0x0006 so that four edge events are counted. The counter is configured to detect both edges of the input signal. Note that the last two edges are not counted because the timer automatically clears the TnEN bit after the current count matches the value in the GPTMTnMATCHR register. June 18, 2014 963 Texas Instruments-Production Data General-Purpose Timers Figure 13-2. Input Edge-Count Mode Example, Counting Down Timer stops, flags asserted Count Timer reload on next cycle Ignored Ignored 0x000A 0x0009 0x0008 0x0007 0x0006 Input Signal 13.3.3.4 Input Edge-Time Mode Note: For rising-edge detection, the input signal must be High for at least two system clock periods following the rising edge. Similarly, for falling edge detection, the input signal must be Low for at least two system clock periods following the falling edge. Based on this criteria, the maximum input frequency for edge detection is 1/4 of the system frequency. In Edge-Time mode, the timer is configured as a 24-bit up- or down-counter including the optional prescaler with the upper timer value stored in the GPTMTnPR register and the lower bits in the GPTMTnILR register. In this mode, the timer is initialized to the value loaded in the GPTMTnILR and GPTMTnPR registers when counting down and 0x0 when counting up. The timer is capable of capturing three types of events: rising edge, falling edge, or both. The timer is placed into Edge-Time mode by setting the TnCMR bit in the GPTMTnMR register, and the type of event that the timer captures is determined by the TnEVENT fields of the GPTMCTL register. Table 13-8 on page 964 shows the values that are loaded into the timer registers when the timer is enabled. Table 13-8. Counter Values When the Timer is Enabled in Input Event-Count Mode Register Count Down Mode Count Up Mode TnR GPTMTnILR 0x0 TnV GPTMTnILR 0x0 When software writes the TnEN bit in the GPTMCTL register, the timer is enabled for event capture. When the selected input event is detected, the current timer counter value is captured in the GPTMTnR and GPTMTnPS register and is available to be read by the microcontroller. The GPTM then asserts the CnERIS bit in the GPTM Raw Interrupt Status (GPTMRIS) register, and holds it until it is cleared by writing the GPTM Interrupt Clear (GPTMICR) register. If the capture mode event interrupt is enabled in the GPTM Interrupt Mask (GPTMIMR) register, the GPTM also sets the CnEMIS bit in the GPTM Masked Interrupt Status (GPTMMIS) register. In this mode, the GPTMTnR and GPTMTnPS registers hold the time at which the selected input event occurred while 964 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller the GPTMTnV register holds the free-running timer value. These registers can be read to determine the time that elapsed between the interrupt assertion and the entry into the ISR. In addition to generating interrupts, an ADC and/or a μDMA trigger can be generated. The ADC trigger is enabled by setting the TnOTE bit in GPTMCTL and the event that activates the ADC is configured in the GPTM ADC Event (GPTMADCEV) register. The μDMA trigger is enabled by configuring the appropriate μDMA channel as well as the type of trigger selected in the GPTM DMA Event (GPTMDMAEV) register. See “Channel Configuration” on page 683. After an event has been captured, the timer does not stop counting. It continues to count until the TnEN bit is cleared. When the timer reaches the timeout value, it is reloaded with 0x0 in up-count mode and the value from the GPTMTnILR and GPTMTnPR registers in down-count mode. Figure 13-3 on page 965 shows how input edge timing mode works. In the diagram, it is assumed that the start value of the timer is the default value of 0xFFFF, and the timer is configured to capture rising edge events. Each time a rising edge event is detected, the current count value is loaded into the GPTMTnR and GPTMTnPS registers, and is held there until another rising edge is detected (at which point the new count value is loaded into the GPTMTnR and GPTMTnPS registers). Figure 13-3. 16-Bit Input Edge-Time Mode Example Count 0xFFFF GPTMTnR=X GPTMTnR=Y GPTMTnR=Z Z X Y Time Input Signal Note: When operating in Edge-time mode, the counter uses a modulo 224 count if prescaler is enabled or 216, if not. If there is a possibility the edge could take longer than the count, then another timer configured in periodic-timer mode can be implemented to ensure detection of the missed edge. The periodic timer should be configured in such a way that: ■ The periodic timer cycles at the same rate as the edge-time timer ■ The periodic timer interrupt has a higher interrupt priority than the edge-time timeout interrupt. ■ If the periodic timer interrupt service routine is entered, software must check if an edge-time interrupt is pending and if it is, the value of the counter must be subtracted by 1 before being used to calculate the snapshot time of the event. June 18, 2014 965 Texas Instruments-Production Data General-Purpose Timers 13.3.3.5 PWM Mode The GPTM supports a simple PWM generation mode. In PWM mode, the timer is configured as a 24-bit down-counter with a start value (and thus period) defined by the GPTMTnILR and GPTMTnPR registers. In this mode, the PWM frequency and period are synchronous events and therefore guaranteed to be glitch free. PWM mode is enabled with the GPTMTnMR register by setting the TnAMS bit to 0x1, the TnCMR bit to 0x0, and the TnMR field to 0x2. Table 13-9 on page 966 shows the values that are loaded into the timer registers when the timer is enabled. Table 13-9. Counter Values When the Timer is Enabled in PWM Mode Register Count Down Mode Count Up Mode GPTMTnR GPTMTnILR Not available GPTMTnV GPTMTnILR Not available When software writes the TnEN bit in the GPTMCTL register, the counter begins counting down until it reaches the 0x0 state. Alternatively, if the TnWOT bit is set in the GPTMTnMR register, once the TnEN bit is set, the timer waits for a trigger to begin counting (see “Wait-for-Trigger Mode” on page 968). On the next counter cycle in periodic mode, the counter reloads its start value from the GPTMTnILR and GPTMTnPR registers and continues counting until disabled by software clearing the TnEN bit in the GPTMCTL register. The timer is capable of generating interrupts based on three types of events: rising edge, falling edge, or both. The event is configured by the TnEVENT field of the GPTMCTL register, and the interrupt is enabled by setting the TnPWMIE bit in the GPTMTnMR register. When the event occurs, the CnERIS bit is set in the GPTM Raw Interrupt Status (GPTMRIS) register, and holds it until it is cleared by writing the GPTM Interrupt Clear (GPTMICR) register . If the capture mode event interrupt is enabled in the GPTM Interrupt Mask (GPTMIMR) register , the GPTM also sets the CnEMIS bit in the GPTM Masked Interrupt Status (GPTMMIS) register. Note that the interrupt status bits are not updated unless the TnPWMIE bit is set. In addition, when the TnPWMIE bit is set and a capture event occurs, the Timer automatically generates triggers to the ADC and DMA if the trigger capability is enabled by setting the TnOTE bit in the GPTMCTL register and the CnEDMAEN bit in the GPTMDMAEV register, respectively. In this mode, the GPTMTnR and GPTMTnV registers always have the same value. The output PWM signal asserts when the counter is at the value of the GPTMTnILR and GPTMTnPR registers (its start state), and is deasserted when the counter value equals the value in the GPTMTnMATCHR and GPTMTnPMR registers. Software has the capability of inverting the output PWM signal by setting the TnPWML bit in the GPTMCTL register. Note: If PWM output inversion is enabled, edge detection interrupt behavior is reversed. Thus, if a positive-edge interrupt trigger has been set and the PWM inversion generates a positive edge, no event-trigger interrupt asserts. Instead, the interrupt is generated on the negative edge of the PWM signal. Figure 13-4 on page 967 shows how to generate an output PWM with a 1-ms period and a 66% duty cycle assuming a 50-MHz input clock and TnPWML =0 (duty cycle would be 33% for the TnPWML =1 configuration). For this example, the start value is GPTMTnILR=0xC350 and the match value is GPTMTnMATCHR=0x411A. 966 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 13-4. 16-Bit PWM Mode Example Count GPTMTnR=GPTMnMR GPTMTnR=GPTMnMR 0xC350 0x411A Time TnEN set TnPWML = 0 Output Signal TnPWML = 1 When synchronizing the timers using the GPTMSYNC register, the timer must be properly configured to avoid glitches on the CCP outputs. Both the TnPLO and the TnMRSU bits must be set in the GPTMTnMR register. Figure 13-5 on page 967 shows how the CCP output operates when the TnPLO and TnMRSU bits are set and the GPTMTnMATCHR value is greater than the GPTMTnILR value. Figure 13-5. CCP Output, GPTMTnMATCHR > GPTMTnILR GPTMnMATCHR CounterValue GPTMnILR CCP CCP set if GPTMnMATCHR ≠ GPTMnILR Figure 13-6 on page 968 shows how the CCP output operates when the PLO and MRSU bits are set and the GPTMTnMATCHR value is the same as the GPTMTnILR value. In this situation, if the PLO bit is 0, the CCP signal goes high when the GPTMTnILR value is loaded and the match would be essentially ignored. June 18, 2014 967 Texas Instruments-Production Data General-Purpose Timers Figure 13-6. CCP Output, GPTMTnMATCHR = GPTMTnILR GPTMnMATCHR CounterValue GPTMnILR CCP CCP not set if GPTMnMATCHR = GPTMnILR Figure 13-7 on page 968 shows how the CCP output operates when the PLO and MRSU bits are set and the GPTMTnILR is greater than the GPTMTnMATCHR value. Figure 13-7. CCP Output, GPTMTnILR > GPTMTnMATCHR GPTMnILR GPTMnMATCHR = GPTMnILR-1 GPTMnMATCHR = GPTMnILR-2 GPTMnMATCHR == 0 13.3.4 CCP Pulse width is 1 clock when GPTMnMATCHR = GPTMnILR - 1 CCP Pulse width is 2 clocks when GPTMnMATCHR = GPTMnILR - 2 CCP Pulse width is GPTMnILR clocks when GPTMnMATCHR= 0 Wait-for-Trigger Mode The Wait-for-Trigger mode allows daisy chaining of the timer modules such that once configured, a single timer can initiate multiple timing events using the Timer triggers. Wait-for-Trigger mode is enabled by setting the TnWOT bit in the GPTMTnMR register. When the TnWOT bit is set, Timer N+1 does not begin counting until the timer in the previous position in the daisy chain (Timer N) reaches its time-out event. The daisy chain is configured such that GPTM1 always follows GPTM0, GPTM2 follows GPTM1, and so on. If Timer A is configured as a 32-bit (16/32-bit mode) timer (controlled by the GPTMCFG field in the GPTMCFG register), it triggers Timer A in the next module. If Timer A is configured as a 16-bit (16/32-bit mode) timer, it triggers Timer B in the same module, and Timer B triggers Timer A in the next module. Figure 13-8 on page 969 shows how the GPTMCFG bit affects the daisy chain. This function is valid for one-shot, periodic, and PWM modes. Note: If the application requires cyclical daisy-chaining, the TAWOT bit in the GPTMTAMR register of Timer 0 can be set. In this case, Timer 0 waits for a trigger from the last timer module in the chain. 968 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 13-8. Timer Daisy Chain GP Timer N+1 1 0 GPTMTnMR.TnWOT Timer B ADC Trigger Timer B Timer A Timer A ADC Trigger GP Timer N 1 0 GPTMTnMR.TnWOT Timer B ADC Trigger Timer B Timer A 13.3.5 Timer A ADC Trigger Synchronizing GP Timer Blocks The GPTM Synchronizer Control (GPTMSYNC) register in the GPTM0 block can be used to synchronize selected timers to begin counting at the same time. Setting a bit in the GPTMSYNC register causes the associated timer to perform the actions of a timeout event. An interrupt is not generated when the timers are synchronized. If a timer is being used in concatenated mode, only the bit for Timer A must be set in the GPTMSYNC register. Note: All timers must use the same clock source for this feature to work correctly. Table 13-10 on page 969 shows the actions for the timeout event performed when the timers are synchronized in the various timer modes. Table 13-10. Timeout Actions for GPTM Modes Mode Count Dir Time Out Action 32-bit One-Shot (concatenated timers) ─ N/A 32-bit Periodic (concatenated timers) Down Count value = ILR Up Count value = 0 32-bit RTC (concatenated timers) Up Count value = 0 16- bit One Shot (individual/split timers) ─ N/A 16-bit Periodic (individual/split timers) Down Count value = ILR Up Count value = 0 16-bit Edge-Count (individual/split timers) Down Count value = ILR Up Count value = 0 16- bit Edge-Time (individual/split timers) Down Count value = ILR Up Count value = 0 16-bit PWM Down Count value = ILR June 18, 2014 969 Texas Instruments-Production Data General-Purpose Timers 13.3.6 DMA Operation The timers each have a dedicated μDMA channel and can provide a request signal to the μDMA controller. Pulse requests are generated by a timer via its own dma_req signal. A dma_done signal is provided from the µDMA to each timer to indicate transfer completion and trigger a µDMA done interrupt (DMAnRIS) in the GPTM Raw Interrupt Status Register (GPTMRIS) register. The request is a burst type and occurs whenever a timer raw interrupt condition occurs. The arbitration size of the μDMA transfer should be set to the amount of data that should be transferred whenever a timer event occurs. For example, to transfer 256 items, 8 items at a time every 10 ms, configure a timer to generate a periodic timeout at 10 ms. Configure the μDMA transfer for a total of 256 items, with a burst size of 8 items. Each time the timer times out, the μDMA controller transfers 8 items, until all 256 items have been transferred. Refer to “Micro Direct Memory Access (μDMA)” on page 678 for more details about programming the μDMA controller. A GPTM DMA Event (GPTMDMAEV) register is provided to enable the types of events that can cause a dma_req signal assertion by the timer module. Application software can enable a dma_req trigger for a match, capture or time-out event for each timer using the GPTMDMAEV register. For an individual timer, all active timer trigger events that have been enabled through the GPTMDMAEV register are ORed together to create a single dma_req pulse that is sent to the µDMA. When the µDMA transfer has completed, a dma_done signal is sent to the timer resulting in a DMAnRIS bit set in the GPTMRIS register. 13.3.7 ADC Operation The timer has the capability to trigger the ADC when the TnOTE bit is set in the GPTMCTL register at offset 0x00C. The GPTM ADC Event (GPTMADCEV) register is additionally provided so that the type of ADC trigger can be defined. For example, by setting the CBMADCEN bit in the GPTMADCEV register, a trigger pulse will be sent to the ADC whenever a Capture Match event occurs in GPTM B. Similar to the µDMA operation, all active trigger events that have also been enabled in the GPTMADCEV register are ORed together to create an ADC trigger pulse. 13.3.8 Accessing Concatenated 16/32-Bit GPTM Register Values The GPTM is placed into concatenated mode by writing a 0x0 or a 0x1 to the GPTMCFG bit field in the GPTM Configuration (GPTMCFG) register. In both configurations, certain 16/32-bit GPTM registers are concatenated to form pseudo 32-bit registers. These registers include: ■ GPTM Timer A Interval Load (GPTMTAILR) register [15:0], see page 1004 ■ GPTM Timer B Interval Load (GPTMTBILR) register [15:0], see page 1005 ■ GPTM Timer A (GPTMTAR) register [15:0], see page 1012 ■ GPTM Timer B (GPTMTBR) register [15:0], see page 1013 ■ GPTM Timer A Value (GPTMTAV) register [15:0], see page 1014 ■ GPTM Timer B Value (GPTMTBV) register [15:0], see page 1015 ■ GPTM Timer A Match (GPTMTAMATCHR) register [15:0], see page 1006 ■ GPTM Timer B Match (GPTMTBMATCHR) register [15:0], see page 1007 970 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller In the 32-bit modes, the GPTM translates a 32-bit write access to GPTMTAILR into a write access to both GPTMTAILR and GPTMTBILR. The resulting word ordering for such a write operation is: GPTMTBILR[15:0]:GPTMTAILR[15:0] Likewise, a 32-bit read access to GPTMTAR returns the value: GPTMTBR[15:0]:GPTMTAR[15:0] A 32-bit read access to GPTMTAV returns the value: GPTMTBV[15:0]:GPTMTAV[15:0] 13.4 Initialization and Configuration To use a GPTM, the appropriate TIMERn bit must be set in the RCGCTIMER register (see page 380 ). If using any CCP pins, the clock to the appropriate GPIO module must be enabled via the RCGCGPIO register (see page 382). To find out which GPIO port to enable, refer to Table 26-4 on page 1797. Configure the PMCn fields in the GPIOPCTL register to assign the CCP signals to the appropriate pins (see page 787 and Table 26-5 on page 1808). This section shows module initialization and configuration examples for each of the supported timer modes. 13.4.1 One-Shot/Periodic Timer Mode The GPTM is configured for One-Shot and Periodic modes by the following sequence: 1. Ensure the timer is disabled (the TnEN bit in the GPTMCTL register is cleared) before making any changes. 2. Write the GPTM Configuration Register (GPTMCFG) with a value of 0x0000.0000. 3. Configure the TnMR field in the GPTM Timer n Mode Register (GPTMTnMR): a. Write a value of 0x1 for One-Shot mode. b. Write a value of 0x2 for Periodic mode. 4. Optionally configure the TnSNAPS, TnWOT, TnMTE, and TnCDIR bits in the GPTMTnMR register to select whether to capture the value of the free-running timer at time-out, use an external trigger to start counting, configure an additional trigger or interrupt, and count up or down. In addition, if using CCP pins, the TCACT field can be programmed to configure the compare action. 5. Load the start value into the GPTM Timer n Interval Load Register (GPTMTnILR). 6. If interrupts are required, set the appropriate bits in the GPTM Interrupt Mask Register (GPTMIMR). 7. Set the TnEN bit in the GPTMCTL register to enable the timer and start counting. 8. Poll the GPTMRIS register or wait for the interrupt to be generated (if enabled). In both cases, the status flags are cleared by writing a 1 to the appropriate bit of the GPTM Interrupt Clear Register (GPTMICR). June 18, 2014 971 Texas Instruments-Production Data General-Purpose Timers If the TnMIE bit in the GPTMTnMR register is set, the RTCRIS bit in the GPTMRIS register is set, and the timer continues counting. In One-Shot mode, the timer stops counting after the time-out event. To re-enable the timer, repeat the sequence. A timer configured in Periodic mode reloads the timer and continues counting after the time-out event. 13.4.2 Real-Time Clock (RTC) Mode To use the RTC mode, the timer must have a 32.768-KHz input signal on an even CCP input. To enable the RTC feature, follow these steps: 1. Ensure the timer is disabled (the TAEN bit is cleared) before making any changes. 2. If the timer has been operating in a different mode prior to this, clear any residual set bits in the GPTM Timer n Mode (GPTMTnMR) register before reconfiguring. 3. Write the GPTM Configuration Register (GPTMCFG) with a value of 0x0000.0001. 4. Write the match value to the GPTM Timer n Match Register (GPTMTnMATCHR). 5. Set/clear the RTCEN and TnSTALL bit in the GPTM Control Register (GPTMCTL) as needed. 6. If interrupts are required, set the RTCIM bit in the GPTM Interrupt Mask Register (GPTMIMR). 7. Set the TAEN bit in the GPTMCTL register to enable the timer and start counting. When the timer count equals the value in the GPTMTnMATCHR register, the GPTM asserts the RTCRIS bit in the GPTMRIS register and continues counting until Timer A is disabled or a hardware reset. The interrupt is cleared by writing the RTCCINT bit in the GPTMICR register. Note that if the GPTMTnILR register is loaded with a new value, the timer begins counting at this new value and continues until it reaches 0xFFFF.FFFF, at which point it rolls over. 13.4.3 Input Edge-Count Mode A timer is configured to Input Edge-Count mode by the following sequence: 1. Ensure the timer is disabled (the TnEN bit is cleared) before making any changes. 2. Write the GPTM Configuration (GPTMCFG) register with a value of 0x0000.0004. 3. In the GPTM Timer Mode (GPTMTnMR) register, write the TnCMR field to 0x0 and the TnMR field to 0x3. 4. Configure the type of event(s) that the timer captures by writing the TnEVENT field of the GPTM Control (GPTMCTL) register. 5. Program registers according to count direction: ■ In down-count mode, the GPTMTnMATCHR and GPTMTnPMR registers are configured so that the difference between the value in the GPTMTnILR and GPTMTnPR registers and the GPTMTnMATCHR and GPTMTnPMR registers equals the number of edge events that must be counted. ■ In up-count mode, the timer counts from 0x0 to the value in the GPTMTnMATCHR and GPTMTnPMR registers. Note that when executing an up-count, the value of the GPTMTnPR and GPTMTnILR must be greater than the value of GPTMTnPMR and GPTMTnMATCHR. 972 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 6. If interrupts are required, set the CnMIM bit in the GPTM Interrupt Mask (GPTMIMR) register. 7. Set the TnEN bit in the GPTMCTL register to enable the timer and begin waiting for edge events. 8. Poll the CnMRIS bit in the GPTMRIS register or wait for the interrupt to be generated (if enabled). In both cases, the status flags are cleared by writing a 1 to the CnMCINT bit of the GPTM Interrupt Clear (GPTMICR) register. When counting down in Input Edge-Count Mode, the timer stops after the programmed number of edge events has been detected. To re-enable the timer, ensure that the TnEN bit is cleared and repeat steps 4 through 8. 13.4.4 Input Edge Time Mode A timer is configured to Input Edge Time mode by the following sequence: 1. Ensure the timer is disabled (the TnEN bit is cleared) before making any changes. 2. Write the GPTM Configuration (GPTMCFG) register with a value of 0x0000.0004. 3. In the GPTM Timer Mode (GPTMTnMR) register, write the TnCMR field to 0x1 and the TnMR field to 0x3 and select a count direction by programming the TnCDIR bit. 4. Configure the type of event that the timer captures by writing the TnEVENT field of the GPTM Control (GPTMCTL) register. 5. If a prescaler is to be used, write the prescale value to the GPTM Timer n Prescale Register (GPTMTnPR). 6. Load the timer start value into the GPTM Timer n Interval Load (GPTMTnILR) register. 7. If interrupts are required, set the CnEIM bit in the GPTM Interrupt Mask (GPTMIMR) register. 8. Set the TnEN bit in the GPTM Control (GPTMCTL) register to enable the timer and start counting. 9. Poll the CnERIS bit in the GPTMRIS register or wait for the interrupt to be generated (if enabled). In both cases, the status flags are cleared by writing a 1 to the CnECINT bit of the GPTM Interrupt Clear (GPTMICR) register. The time at which the event happened can be obtained by reading the GPTM Timer n (GPTMTnR) register. In Input Edge Timing mode, the timer continues running after an edge event has been detected, but the timer interval can be changed at any time by writing the GPTMTnILR register and clearing the TnILD bit in the GPTMTnMR register. The change takes effect at the next cycle after the write. 13.4.5 PWM Mode A timer is configured to PWM mode using the following sequence: 1. Ensure the timer is disabled (the TnEN bit is cleared) before making any changes. 2. Write the GPTM Configuration (GPTMCFG) register with a value of 0x0000.0004. 3. In the GPTM Timer Mode (GPTMTnMR) register, set the TnAMS bit to 0x1, the TnCMR bit to 0x0, and the TnMR field to 0x2. June 18, 2014 973 Texas Instruments-Production Data General-Purpose Timers 4. Configure the output state of the PWM signal (whether or not it is inverted) in the TnPWML field of the GPTM Control (GPTMCTL) register. 5. If a prescaler is to be used, write the prescale value to the GPTM Timer n Prescale Register (GPTMTnPR). 6. If PWM interrupts are used, configure the interrupt condition in the TnEVENT field in the GPTMCTL register and enable the interrupts by setting the TnPWMIE bit in the GPTMTnMR register. Note that edge detect interrupt behavior is reversed when the PWM output is inverted (see page 986). 7. Load the timer start value into the GPTM Timer n Interval Load (GPTMTnILR) register. 8. Load the GPTM Timer n Match (GPTMTnMATCHR) register with the match value. 9. Set the TnEN bit in the GPTM Control (GPTMCTL) register to enable the timer and begin generation of the output PWM signal. In PWM Time mode, the timer continues running after the PWM signal has been generated. The PWM period can be adjusted at any time by writing the GPTMTnILR register, and the change takes effect at the next cycle after the write. 13.5 Register Map Table 13-11 on page 974 lists the GPTM registers. The offset listed is a hexadecimal increment to the register's address, relative to that timer's base address: ■ ■ ■ ■ ■ ■ ■ ■ 16/32-bit Timer 0: 0x4003.0000 16/32-bit Timer 1: 0x4003.1000 16/32-bit Timer 2: 0x4003.2000 16/32-bit Timer 3: 0x4003.3000 16/32-bit Timer 4: 0x4003.4000 16/32-bit Timer 5: 0x4003.5000 16/32-bit Timer 6: 0x400E.0000 16/32-bit Timer 7: 0x400E.1000 Note that the GP Timer module clock must be enabled before the registers can be programmed (see page 380). There must be a delay of 3 system clocks after the Timer module clock is enabled before any Timer module registers are accessed. Table 13-11. Timers Register Map Offset Name 0x000 Description See page Type Reset GPTMCFG RW 0x0000.0000 GPTM Configuration 976 0x004 GPTMTAMR RW 0x0000.0000 GPTM Timer A Mode 977 0x008 GPTMTBMR RW 0x0000.0000 GPTM Timer B Mode 982 0x00C GPTMCTL RW 0x0000.0000 GPTM Control 986 0x010 GPTMSYNC RW 0x0000.0000 GPTM Synchronize 990 0x018 GPTMIMR RW 0x0000.0000 GPTM Interrupt Mask 993 974 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 13-11. Timers Register Map (continued) Offset Name 0x01C Reset GPTMRIS RO 0x0000.0000 GPTM Raw Interrupt Status 996 0x020 GPTMMIS RO 0x0000.0000 GPTM Masked Interrupt Status 999 0x024 GPTMICR W1C 0x0000.0000 GPTM Interrupt Clear 1002 0x028 GPTMTAILR RW 0xFFFF.FFFF GPTM Timer A Interval Load 1004 0x02C GPTMTBILR RW 0x0000.FFFF GPTM Timer B Interval Load 1005 0x030 GPTMTAMATCHR RW 0xFFFF.FFFF GPTM Timer A Match 1006 0x034 GPTMTBMATCHR RW 0x0000.FFFF GPTM Timer B Match 1007 0x038 GPTMTAPR RW 0x0000.0000 GPTM Timer A Prescale 1008 0x03C GPTMTBPR RW 0x0000.0000 GPTM Timer B Prescale 1009 0x040 GPTMTAPMR RW 0x0000.0000 GPTM TimerA Prescale Match 1010 0x044 GPTMTBPMR RW 0x0000.0000 GPTM TimerB Prescale Match 1011 0x048 GPTMTAR RO 0xFFFF.FFFF GPTM Timer A 1012 0x04C GPTMTBR RO 0x0000.FFFF GPTM Timer B 1013 0x050 GPTMTAV RW 0xFFFF.FFFF GPTM Timer A Value 1014 0x054 GPTMTBV RW 0x0000.FFFF GPTM Timer B Value 1015 0x058 GPTMRTCPD RO 0x0000.7FFF GPTM RTC Predivide 1016 0x05C GPTMTAPS RO 0x0000.0000 GPTM Timer A Prescale Snapshot 1017 0x060 GPTMTBPS RO 0x0000.0000 GPTM Timer B Prescale Snapshot 1018 0x06C GPTMDMAEV RW 0x0000.0000 GPTM DMA Event 1019 0x070 GPTMADCEV RW 0x0000.0000 GPTM ADC Event 1022 0xFC0 GPTMPP RO 0x0000.0070 GPTM Peripheral Properties 1025 0xFC8 GPTMCC RW 0x0000.0000 GPTM Clock Configuration 1027 13.6 Description See page Type Register Descriptions The remainder of this section lists and describes the GPTM registers, in numerical order by address offset. June 18, 2014 975 Texas Instruments-Production Data General-Purpose Timers Register 1: GPTM Configuration (GPTMCFG), offset 0x000 This register configures the global operation of the GPTM module. The value written to this register determines whether the GPTM is in 32- or 16-bit mode. Important: Bits in this register should only be changed when the TAEN and TBEN bits in the GPTMCTL register are cleared. GPTM Configuration (GPTMCFG) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 5 4 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:3 reserved RO 0x0000.000 2:0 GPTMCFG RW 0x0 GPTMCFG RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Configuration The GPTMCFG values are defined as follows: Value Description 0x0 For a 16/32-bit timer, this value selects the 32-bit timer configuration. 0x1 For a 16/32-bit timer, this value selects the 32-bit real-time clock (RTC) counter configuration. 0x2-0x3 Reserved 0x4 For a 16/32-bit timer, this value selects the 16-bit timer configuration. The function is controlled by bits 1:0 of GPTMTAMR and GPTMTBMR. 0x5-0x7 Reserved 976 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: GPTM Timer A Mode (GPTMTAMR), offset 0x004 This register configures the GPTM based on the configuration selected in the GPTMCFG register. When in PWM mode, set the TAAMS bit, clear the TACMR bit, and configure the TAMR field to 0x1 or 0x2. This register controls the modes for Timer A when it is used individually. When Timer A and Timer B are concatenated, this register controls the modes for both Timer A and Timer B, and the contents of GPTMTBMR are ignored. Important: Except for the TCACT bit field, all other bits in this register should only be changed when the TAEN bit in the GPTMCTL register is cleared. GPTM Timer A Mode (GPTMTAMR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x004 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 TACINTD TAPLO RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 TAMIE TACDIR TAAMS TACMR RW 0 RW 0 RW 0 RW 0 reserved Type Reset TCACT Type Reset RW 0 RW 0 RW 0 TAMRSU TAPWMIE RW 0 RW 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000.00 15:13 TCACT RW 0x0 TAILD RW 0 TASNAPS TAWOT RW 0 RW 0 TAMR RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Timer Compare Action Select Value Description 0x0 Disable compare operations. 0x1 Toggle State on Time-Out 0x2 Clear CCP on Time-Out 0x3 Set CCP on Time-Out 0x4 Set CCP immediately and toggle on Time-Out 0x5 Clear CCP immediately and toggle on Time-Out 0x6 Set CCP immediately and clear on Time-Out 0x7 Clear CCP immediately and set on Time-Out June 18, 2014 977 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 12 TACINTD RW 0 Description One-shot/Periodic Interrupt Disable Value Description 0 Time-out interrupt functions as normal. 1 Time-out interrupt are disabled. Note: 11 TAPLO RW 0 Setting the TACINTD bit in the GPTMTAMR register does not have an effect on the µDMA or ADC interrupt time-out event trigger assertions. If the TATODMAEN bit is set in the GPTMDMAEV register or the TATOADCEN bit is set in the GPTMADCEV register, a µDMA or ADC time-out trigger is sent to the µDMA or ADC, respectively, even if the TACINTD bit is set. GPTM Timer A PWM Legacy Operation Value Description 0 Legacy operation with CCP pin driven Low when the GPTMTAILR is reloaded after the timer reaches 0. 1 CCP is driven High when the GPTMTAILR is reloaded after the timer reaches 0. This bit is only valid in PWM mode. 10 TAMRSU RW 0 GPTM Timer A Match Register Update Value Description 0 Update the GPTMTAMATCHR register and the GPTMTAPR register, if used, on the next cycle. 1 Update the GPTMTAMATCHR register and the GPTMTAPR register, if used, on the next timeout. If the timer is disabled (TAEN is clear) when this bit is set, GPTMTAMATCHR and GPTMTAPR are updated when the timer is enabled. If the timer is stalled (TASTALL is set), GPTMTAMATCHR and GPTMTAPR are updated according to the configuration of this bit. 9 TAPWMIE RW 0 GPTM Timer A PWM Interrupt Enable This bit enables interrupts in PWM mode on rising, falling, or both edges of the CCP output, as defined by the TAEVENT field in the GPTMCTL register. In addition, when this bit is set and a capture event occurs, Timer A automatically generates triggers to the ADC and DMA if the trigger capability is enabled by setting the TAOTE bit in the GPTMCTL register and the CAEDMAEN bit in the GPTMDMAEV register, respectively. Value Description 0 Capture event interrupt is disabled. 1 Capture event interrupt is enabled. This bit is only valid in PWM mode. 978 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 8 TAILD RW 0 Description GPTM Timer A Interval Load Write Value Description 0 Update the GPTMTAR and GPTMTAV registers with the value in the GPTMTAILR register on the next cycle. Also update the GPTMTAPS register with the value in the GPTMTAPR register on the next cycle. 1 Update the GPTMTAR and GPTMTAV registers with the value in the GPTMTAILR register on the next timeout. Also update the GPTMTAPS register with the value in the GPTMTAPR register on the next timeout. Note the state of this bit has no effect when counting up. The bit descriptions above apply if the timer is enabled and running. If the timer is disabled (TAEN is clear) when this bit is set, GPTMTAR GPTMTAV and GPTMTAPs, are updated when the timer is enabled. If the timer is stalled (TASTALL is set), GPTMTAR and GPTMTAPS are updated according to the configuration of this bit. 7 TASNAPS RW 0 GPTM Timer A Snap-Shot Mode Value Description 6 TAWOT RW 0 0 Snap-shot mode is disabled. 1 If Timer A is configured in the periodic mode, the actual free-running, capture or snapshot value of Timer A is loaded at the time-out event/capture or snapshot event into the GPTM Timer A (GPTMTAR) register. If the timer prescaler is used, the prescaler snapshot is loaded into the GPTM Timer A (GPTMTAPR). GPTM Timer A Wait-on-Trigger Note: If the application requires cyclical daisy-chaining, the TAWOT bit in the GPTMTAMR register of Timer 0 can be set. In this case, Timer 0 waits for a trigger from the last timer module in the chain. Value Description 0 Timer A begins counting as soon as it is enabled. 1 If Timer A is enabled (TAEN is set in the GPTMCTL register), Timer A does not begin counting until it receives a trigger from the timer in the previous position in the daisy chain, see Figure 13-8 on page 969. This function is valid for one-shot, periodic, and PWM modes. June 18, 2014 979 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 5 TAMIE RW 0 Description GPTM Timer A Match Interrupt Enable Value Description 0 The match interrupt is disabled for match events. Note: 1 4 TACDIR RW 0 Clearing the TAMIE bit in the GPTMTAMR register prevents assertion of µDMA or ADC requests generated on a match event. Even if the TATODMAEN bit is set in the GPTMDMAEV register or the TATOADCEN bit is set in the GPTMADCEV register, a µDMA or ADC match trigger is not sent to the µDMA or ADC, respectively, when the TAMIE bit is clear. An interrupt is generated when the match value in the GPTMTAMATCHR register is reached in the one-shot and periodic modes. GPTM Timer A Count Direction Value Description 0 The timer counts down. 1 The timer counts up. When counting up, the timer starts from a value of 0x0. When in PWM or RTC mode, the status of this bit is ignored. PWM mode always counts down and RTC mode always counts up. 3 TAAMS RW 0 GPTM Timer A Alternate Mode Select The TAAMS values are defined as follows: Value Description 0 Capture or compare mode is enabled. 1 PWM mode is enabled. Note: 2 TACMR RW 0 To enable PWM mode, you must also clear the TACMR bit and configure the TAMR field to 0x1 or 0x2. GPTM Timer A Capture Mode The TACMR values are defined as follows: Value Description 0 Edge-Count mode 1 Edge-Time mode 980 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1:0 TAMR RW 0x0 Description GPTM Timer A Mode The TAMR values are defined as follows: Value Description 0x0 Reserved 0x1 One-Shot Timer mode 0x2 Periodic Timer mode 0x3 Capture mode The Timer mode is based on the timer configuration defined by bits 2:0 in the GPTMCFG register. June 18, 2014 981 Texas Instruments-Production Data General-Purpose Timers Register 3: GPTM Timer B Mode (GPTMTBMR), offset 0x008 This register configures the GPTM based on the configuration selected in the GPTMCFG register. When in PWM mode, set the TBAMS bit, clear the TBCMR bit, and configure the TBMR field to 0x1 or 0x2. This register controls the modes for Timer B when it is used individually. When Timer A and Timer B are concatenated, this register is ignored and GPTMTAMR controls the modes for both Timer A and Timer B. Important: Except for the TCACT bit field, all other bits in this register should only be changed when the TBEN bit in the GPTMCTL register is cleared. GPTM Timer B Mode (GPTMTBMR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 TBCINTD TBPLO RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 TBMIE TBCDIR TBAMS TBCMR RW 0 RW 0 RW 0 RW 0 reserved Type Reset TCACT Type Reset RW 0 RW 0 RW 0 TBMRSU TBPWMIE RW 0 RW 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000.00 15:13 TCACT RW 0x0 TBILD RW 0 TBSNAPS TBWOT RW 0 RW 0 TBMR RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Timer Compare Action Select Value Description 0x0 Disable compare operations 0x1 Toggle State on Time-Out 0x2 Clear CCP on Time-Out 0x3 Set CCP on Time-Out 0x4 Set CCP immediately and toggle on Time-Out 0x5 Clear CCP immediately and toggle on Time-Out 0x6 Set CCP immediately and clear on Time-Out 0x7 Clear CCP immediately and set on Time-Out 982 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 12 TBCINTD RW 0 Description One-Shot/Periodic Interrupt Disable Value Description 0 Time-out interrupt functions normally 1 Time-out interrupt functionality is disabled Note: 11 TBPLO RW 0 Setting the TBCINTD bit in the GPTMTBMR register does not have an effect on the µDMA or ADC interrupt time-out event trigger assertions. If the TBTODMAEN bit is set in the GPTMDMAEV register or the TBTOADCEN bit is set in the GPTMADCEV register, a µDMA or ADC time-out trigger is sent to the µDMA or ADC, respectively, even if the TBCINTD bit is set. GPTM Timer B PWM Legacy Operation Value Description 0 Legacy operation with CCP pin driven Low when the GPTMTAILR is reloaded after the timer reaches 0. 1 CCP is driven High when the GPTMTAILR is reloaded after the timer reaches 0. This bit is only valid in PWM mode. 10 TBMRSU RW 0 GPTM Timer B Match Register Update Value Description 0 Update the GPTMTBMATCHR register and the GPTMTBPR register, if used, on the next cycle. 1 Update the GPTMTBMATCHR register and the GPTMTBPR register, if used, on the next timeout. If the timer is disabled (TBEN is clear) when this bit is set, GPTMTBMATCHR and GPTMTBPR are updated when the timer is enabled. If the timer is stalled (TBSTALL is set), GPTMTBMATCHR and GPTMTBPR are updated according to the configuration of this bit. 9 TBPWMIE RW 0 GPTM Timer B PWM Interrupt Enable This bit enables interrupts in PWM mode on rising, falling, or both edges of the CCP output as defined by the TBEVENT field in the GPTMCTL register. In addition, when this bit is set and a capture event occurs, Timer B automatically generates triggers to the ADC and DMA if the trigger capability is enabled by setting the TBOTE bit in the GPTMCTL register and the CBEDMAEN bit in the GPTMDMAEV register, respectively. Value Description 0 Capture event interrupt is disabled. 1 Capture event is enabled. This bit is only valid in PWM mode. June 18, 2014 983 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 8 TBILD RW 0 Description GPTM Timer B Interval Load Write Value Description 0 Update the GPTMTBR and GPTMTBV registers with the value in the GPTMTBILR register on the next cycle. Also update the GPTMTBPS register with the value in the GPTMTBPR register on the next cycle. 1 Update the GPTMTBR and GPTMTBV registers with the value in the GPTMTBILR register on the next timeout. Also update the GPTMTBPS register with the value in the GPTMTBPR register on the next timeout. Note the state of this bit has no effect when counting up. The bit descriptions above apply if the timer is enabled and running. If the timer is disabled (TBEN is clear) when this bit is set, GPTMTBR, GPTMTBV and are updated when the timer is enabled. If the timer is stalled (TBSTALL is set), GPTMTBR and GPTMTBPS are updated according to the configuration of this bit. 7 TBSNAPS RW 0 GPTM Timer B Snap-Shot Mode Value Description 6 TBWOT RW 0 0 Snap-shot mode is disabled. 1 If Timer B is configured in the periodic mode, the actual free-running value of Timer B is loaded at the time-out event into the GPTM Timer B (GPTMTBR) register. If the timer prescaler is used, the prescaler snapshot is loaded into the GPTM Timer B (GPTMTBPR). GPTM Timer B Wait-on-Trigger Value Description 5 TBMIE RW 0 0 Timer B begins counting as soon as it is enabled. 1 If Timer B is enabled (TBEN is set in the GPTMCTL register), Timer B does not begin counting until it receives a trigger from the timer in the previous position in the daisy chain, see . This function is valid for one-shot, periodic, and PWM modes. GPTM Timer B Match Interrupt Enable Value Description 0 The match interrupt is disabled for match events. Additionally, triggers to the DMA and ADC on match events are prevented. 1 An interrupt is generated when the match value in the GPTMTBMATCHR register is reached in the one-shot and periodic modes. Note: Clearing the TBMIE bit in the GPTMTBMR register prevents assertion of µDMA or ADC requests generated on a match event. Even if the TBTODMAEN bit is set in the GPTMDMAEV register or the TBTOADCEN bit is set in the GPTMADCEV register, a µDMA or ADC match trigger is not sent to the µDMA or ADC, respectively, when the TBMIE bit is clear. 984 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 TBCDIR RW 0 Description GPTM Timer B Count Direction Value Description 0 The timer counts down. 1 The timer counts up. When counting up, the timer starts from a value of 0x0. When in PWM or RTC mode, the status of this bit is ignored. PWM mode always counts down and RTC mode always counts up. 3 TBAMS RW 0 GPTM Timer B Alternate Mode Select The TBAMS values are defined as follows: Value Description 0 Capture or compare mode is enabled. 1 PWM mode is enabled. Note: 2 TBCMR RW 0 To enable PWM mode, you must also clear the TBCMR bit and configure the TBMR field to 0x1 or 0x2. GPTM Timer B Capture Mode The TBCMR values are defined as follows: Value Description 1:0 TBMR RW 0x0 0 Edge-Count mode 1 Edge-Time mode GPTM Timer B Mode The TBMR values are defined as follows: Value Description 0x0 Reserved 0x1 One-Shot Timer mode 0x2 Periodic Timer mode 0x3 Capture mode The timer mode is based on the timer configuration defined by bits 2:0 in the GPTMCFG register. June 18, 2014 985 Texas Instruments-Production Data General-Purpose Timers Register 4: GPTM Control (GPTMCTL), offset 0x00C This register is used alongside the GPTMCFG and GMTMTnMR registers to fine-tune the timer configuration, and to enable other features such as timer stall and the output trigger. The output trigger can be used to initiate transfers on the ADC module. Important: Bits in this register should only be changed when the TnEN bit for the respective timer is cleared. GPTM Control (GPTMCTL) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x00C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 3 2 reserved Type Reset RO 0 RO 0 15 14 reserved TBPWML Type Reset RO 0 RW 0 RO 0 RO 0 RO 0 RO 0 11 10 13 12 TBOTE reserved RW 0 RO 0 TBEVENT RW 0 RW 0 RO 0 RO 0 9 8 TBSTALL TBEN RW 0 RW 0 Bit/Field Name Type Reset 31:15 reserved RO 0x0000 14 TBPWML RW 0 reserved TAPWML RO 0 5 4 TAOTE RTCEN RW 0 RW 0 RW 0 TAEVENT RW 0 RW 0 1 0 TASTALL TAEN RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B PWM Output Level The TBPWML values are defined as follows: Value Description 13 TBOTE RW 0 0 Output is unaffected. 1 Output is inverted. GPTM Timer B Output Trigger Enable The TBOTE values are defined as follows: Value Description 0 The output Timer B ADC trigger is disabled. 1 The output Timer B ADC trigger is enabled. In addition, the ADC must be enabled and the timer selected as a trigger source with the EMn bit in the ADCEMUX register (see page 1091). 12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 986 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 11:10 TBEVENT RW 0x0 Description GPTM Timer B Event Mode The TBEVENT values are defined as follows: Value Description 0x0 Positive edge 0x1 Negative edge 0x2 Reserved 0x3 Both edges Note: 9 TBSTALL RW 0 If PWM output inversion is enabled, edge detection interrupt behavior is reversed. Thus, if a positive-edge interrupt trigger has been set and the PWM inversion generates a postive edge, no event-trigger interrupt asserts. Instead, the interrupt is generated on the negative edge of the PWM signal. GPTM Timer B Stall Enable The TBSTALL values are defined as follows: Value Description 0 Timer B continues counting while the processor is halted by the debugger. 1 Timer B freezes counting while the processor is halted by the debugger. If the processor is executing normally, the TBSTALL bit is ignored. 8 TBEN RW 0 GPTM Timer B Enable The TBEN values are defined as follows: Value Description 0 Timer B is disabled. 1 Timer B is enabled and begins counting or the capture logic is enabled based on the GPTMCFG register. 7 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 6 TAPWML RW 0 GPTM Timer A PWM Output Level The TAPWML values are defined as follows: Value Description 0 Output is unaffected. 1 Output is inverted. June 18, 2014 987 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 5 TAOTE RW 0 Description GPTM Timer A Output Trigger Enable The TAOTE values are defined as follows: Value Description 0 The output Timer A ADC trigger is disabled. 1 The output Timer A ADC trigger is enabled. In addition, the ADC must be enabled and the timer selected as a trigger source with the EMn bit in the ADCEMUX register (see page 1091). 4 RTCEN RW 0 GPTM RTC Stall Enable The RTCEN values are defined as follows: Value Description 0 RTC counting freezes while the processor is halted by the debugger. 1 RTC counting continues while the processor is halted by the debugger. If the RTCEN bit is set, it prevents the timer from stalling in all operating modes, even if TnSTALL is set. 3:2 TAEVENT RW 0x0 GPTM Timer A Event Mode The TAEVENT values are defined as follows: Value Description 0x0 Positive edge 0x1 Negative edge 0x2 Reserved 0x3 Both edges Note: 1 TASTALL RW 0 If PWM output inversion is enabled, edge detection interrupt behavior is reversed. Thus, if a positive-edge interrupt trigger has been set and the PWM inversion generates a postive edge, no event-trigger interrupt asserts. Instead, the interrupt is generated on the negative edge of the PWM signal. GPTM Timer A Stall Enable The TASTALL values are defined as follows: Value Description 0 Timer A continues counting while the processor is halted by the debugger. 1 Timer A freezes counting while the processor is halted by the debugger. If the processor is executing normally, the TASTALL bit is ignored. 988 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 TAEN RW 0 Description GPTM Timer A Enable The TAEN values are defined as follows: Value Description 0 Timer A is disabled. 1 Timer A is enabled and begins counting or the capture logic is enabled based on the GPTMCFG register. June 18, 2014 989 Texas Instruments-Production Data General-Purpose Timers Register 5: GPTM Synchronize (GPTMSYNC), offset 0x010 Note: This register is only implemented on GPTM Module 0 only. This register allows software to synchronize a number of timers. GPTM Synchronize (GPTMSYNC) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 reserved Type Reset SYNCT7 Type Reset WO 0 WO 0 SYNCT6 WO 0 WO 0 SYNCT5 WO 0 WO 0 SYNCT4 WO 0 SYNCT3 SYNCT2 SYNCT1 SYNCT0 WO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:14 SYNCT7 WO 0x0 Synchronize GPTM Timer 7 Value Description 13:12 SYNCT6 WO 0x0 0x0 GPT7 is not affected. 0x1 A timeout event for Timer A of GPTM7 is triggered. 0x2 A timeout event for Timer B of GPTM7 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM7 is triggered. Synchronize GPTM Timer 6 Value Description 0x0 GPTM6 is not affected. 0x1 A timeout event for Timer A of GPTM6 is triggered. 0x2 A timeout event for Timer B of GPTM6 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM6 is triggered. 990 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 11:10 SYNCT5 WO 0x0 Description Synchronize GPTM Timer 5 Value Description 9:8 SYNCT4 WO 0x0 0x0 GPTM5 is not affected. 0x1 A timeout event for Timer A of GPTM5 is triggered. 0x2 A timeout event for Timer B of GPTM5 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM5 is triggered. Synchronize GPTM Timer 4 Value Description 7:6 SYNCT3 WO 0x0 0x0 GPTM4 is not affected. 0x1 A timeout event for Timer A of GPTM4 is triggered. 0x2 A timeout event for Timer B of GPTM4 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM4 is triggered. Synchronize GPTM Timer 3 Value Description 5:4 SYNCT2 WO 0x0 0x0 GPTM3 is not affected. 0x1 A timeout event for Timer A of GPTM3 is triggered. 0x2 A timeout event for Timer B of GPTM3 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM3 is triggered. Synchronize GPTM Timer 2 Value Description 3:2 SYNCT1 WO 0x0 0x0 GPTM2 is not affected. 0x1 A timeout event for Timer A of GPTM2 is triggered. 0x2 A timeout event for Timer B of GPTM2 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM2 is triggered. Synchronize GPTM Timer 1 Value Description 0x0 GPTM1 is not affected. 0x1 A timeout event for Timer A of GPTM1 is triggered. 0x2 A timeout event for Timer B of GPTM1 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM1 is triggered. June 18, 2014 991 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 1:0 SYNCT0 WO 0x0 Description Synchronize GPTM Timer 0 Value Description 0x0 GPTM0 is not affected. 0x1 A timeout event for Timer A of GPTM0 is triggered. 0x2 A timeout event for Timer B of GPTM0 is triggered. 0x3 A timeout event for both Timer A and Timer B of GPTM0 is triggered. 992 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 6: GPTM Interrupt Mask (GPTMIMR), offset 0x018 This register allows software to enable/disable GPTM controller-level interrupts. Setting a bit enables the corresponding interrupt, while clearing a bit disables it. GPTM Interrupt Mask (GPTMIMR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x018 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 15 14 reserved Type Reset RO 0 RO 0 RO 0 RO 0 13 12 DMABIM reserved RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 11 10 9 8 TBMIM CBEIM CBMIM TBTOIM RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:14 reserved RO 0x0000 13 DMABIM RW 0 reserved RO 0 5 4 3 2 1 0 DMAAIM TAMIM RTCIM CAEIM CAMIM TATOIM RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B DMA Done Interrupt Mask The DMABIM values are defined as follows: Value Description 12 reserved RO 0x0 11 TBMIM RW 0 0 Interrupt is disabled. 1 Interrupt is enabled. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B Match Interrupt Mask The TBMIM values are defined as follows: Value Description 10 CBEIM RW 0 0 Interrupt is disabled. 1 Interrupt is enabled. GPTM Timer B Capture Mode Event Interrupt Mask The CBEIM values are defined as follows: Value Description 0 Interrupt is disabled. 1 Interrupt is enabled. June 18, 2014 993 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 9 CBMIM RW 0 Description GPTM Timer B Capture Mode Match Interrupt Mask The CBMIM values are defined as follows: Value Description 8 TBTOIM RW 0 0 Interrupt is disabled. 1 Interrupt is enabled. GPTM Timer B Time-Out Interrupt Mask The TBTOIM values are defined as follows: Value Description 0 Interrupt is disabled. 1 Interrupt is enabled. 7:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5 DMAAIM RW 0 GPTM Timer A DMA Done Interrupt Mask The DMAAIM values are defined as follows: Value Description 4 TAMIM RW 0 0 Interrupt is disabled. 1 Interrupt is enabled. GPTM Timer A Match Interrupt Mask The TAMIM values are defined as follows: Value Description 3 RTCIM RW 0 0 Interrupt is disabled. 1 Interrupt is enabled. GPTM RTC Interrupt Mask The RTCIM values are defined as follows: Value Description 2 CAEIM RW 0 0 Interrupt is disabled. 1 Interrupt is enabled. GPTM Timer A Capture Mode Event Interrupt Mask The CAEIM values are defined as follows: Value Description 0 Interrupt is disabled. 1 Interrupt is enabled. 994 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1 CAMIM RW 0 Description GPTM Timer A Capture Mode Match Interrupt Mask The CAMIM values are defined as follows: Value Description 0 TATOIM RW 0 0 Interrupt is disabled. 1 Interrupt is enabled. GPTM Timer A Time-Out Interrupt Mask The TATOIM values are defined as follows: Value Description 0 Interrupt is disabled. 1 Interrupt is enabled. June 18, 2014 995 Texas Instruments-Production Data General-Purpose Timers Register 7: GPTM Raw Interrupt Status (GPTMRIS), offset 0x01C This register shows the state of the GPTM's internal interrupt signal. These bits are set whether or not the interrupt is masked in the GPTMIMR register. Each bit can be cleared by writing a 1 to its corresponding bit in GPTMICR. Note: The state of the GPTMRIS register is not affected by disabling and then re-enabling the timer using the TnEN bits in the GPTM Control (GPTMCTL) register. If an application requires that all or certain status bits should not carry over after re-enabling the timer, then the appropriate bits in the GPTMRIS register should be cleared using the GPTMICR register prior to re-enabling the timer. If this is not done, any status bits set in the GPTMRIS register and unmasked in the GPTMIMR register generate an interrupt once the timer is re-enabled. GPTM Raw Interrupt Status (GPTMRIS) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x01C Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 TBMRIS CBERIS RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RTCRIS CAERIS RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 DMABRIS reserved RO 0 RO 0 CBMRIS TBTORIS RO 0 Bit/Field Name Type Reset 31:14 reserved RO 0x0000 13 DMABRIS RO 0 RO 0 reserved RO 0 DMAARIS TAMRIS RO 0 RO 0 RO 0 CAMRIS TATORIS RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B DMA Done Raw Interrupt Status Value Description 12 reserved RO 0x0 0 The Timer B DMA transfer has not completed. 1 The Timer B DMA transfer has completed. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 996 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 11 TBMRIS RO 0 Description GPTM Timer B Match Raw Interrupt Value Description 0 The match value has not been reached. 1 The TBMIE bit is set in the GPTMTBMR register, and the match values in the GPTMTBMATCHR and (optionally) GPTMTBPMR registers have been reached when configured in one-shot or periodic mode. This bit is cleared by writing a 1 to the TBMCINT bit in the GPTMICR register. 10 CBERIS RO 0 GPTM Timer B Capture Mode Event Raw Interrupt Value Description 0 The capture mode event for Timer B has not occurred. 1 A capture mode event has occurred for Timer B. This interrupt asserts when the subtimer is configured in Input Edge-Time mode. This bit is cleared by writing a 1 to the CBECINT bit in the GPTMICR register. 9 CBMRIS RO 0 GPTM Timer B Capture Mode Match Raw Interrupt Value Description 0 The capture mode match for Timer B has not occurred. 1 The capture mode match has occurred for Timer B. This interrupt asserts when the values in the GPTMTBR and GPTMTBPR match the values in the GPTMTBMATCHR and GPTMTBPMR when configured in Input Edge-Time mode. This bit is cleared by writing a 1 to the CBMCINT bit in the GPTMICR register. 8 TBTORIS RO 0 GPTM Timer B Time-Out Raw Interrupt Value Description 0 Timer B has not timed out. 1 Timer B has timed out. This interrupt is asserted when a one-shot or periodic mode timer reaches it's count limit (0 or the value loaded into GPTMTBILR, depending on the count direction). This bit is cleared by writing a 1 to the TBTOCINT bit in the GPTMICR register. 7:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5 DMAARIS RO 0 GPTM Timer A DMA Done Raw Interrupt Status Value Description 0 The Timer A DMA transfer has not completed. 1 The Timer A DMA transfer has completed. June 18, 2014 997 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 4 TAMRIS RO 0 Description GPTM Timer A Match Raw Interrupt Value Description 0 The match value has not been reached. 1 The TAMIE bit is set in the GPTMTAMR register, and the match value in the GPTMTAMATCHR and (optionally) GPTMTAPMR registers have been reached when configured in one-shot or periodic mode. This bit is cleared by writing a 1 to the TAMCINT bit in the GPTMICR register. 3 RTCRIS RO 0 GPTM RTC Raw Interrupt Value Description 0 The RTC event has not occurred. 1 The RTC event has occurred. This bit is cleared by writing a 1 to the RTCCINT bit in the GPTMICR register. 2 CAERIS RO 0 GPTM Timer A Capture Mode Event Raw Interrupt Value Description 0 The capture mode event for Timer A has not occurred. 1 A capture mode event has occurred for Timer A. This interrupt asserts when the subtimer is configured in Input Edge-Time mode. This bit is cleared by writing a 1 to the CAECINT bit in the GPTMICR register. 1 CAMRIS RO 0 GPTM Timer A Capture Mode Match Raw Interrupt Value Description 0 The capture mode match for Timer A has not occurred. 1 A capture mode match has occurred for Timer A. This interrupt asserts when the values in the GPTMTAR and GPTMTAPR match the values in the GPTMTAMATCHR and GPTMTAPMR when configured in Input Edge-Time mode. This bit is cleared by writing a 1 to the CAMCINT bit in the GPTMICR register. 0 TATORIS RO 0 GPTM Timer A Time-Out Raw Interrupt Value Description 0 Timer A has not timed out. 1 Timer A has timed out. This interrupt is asserted when a one-shot or periodic mode timer reaches it's count limit (0 or the value loaded into GPTMTAILR, depending on the count direction). This bit is cleared by writing a 1 to the TATOCINT bit in the GPTMICR register. 998 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: GPTM Masked Interrupt Status (GPTMMIS), offset 0x020 This register show the state of the GPTM's controller-level interrupt. If an interrupt is unmasked in GPTMIMR, and there is an event that causes the interrupt to be asserted, the corresponding bit is set in this register. All bits are cleared by writing a 1 to the corresponding bit in GPTMICR. GPTM Masked Interrupt Status (GPTMMIS) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x020 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 2 1 0 reserved Type Reset RO 0 RO 0 15 14 reserved Type Reset RO 0 RO 0 RO 0 RO 0 13 12 DMABMIS reserved RO 0 RO 0 RO 0 11 TBMMIS RO 0 RO 0 RO 0 RO 0 RO 0 10 9 8 7 6 CBEMIS CBMMIS TBTOMIS RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:14 reserved RO 0x0000 13 DMABMIS RO 0 RO 0 reserved RO 0 DMAAMIS TAMMIS RO 0 RO 0 3 RTCMIS RO 0 RO 0 CAEMIS CAMMIS TATOMIS RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B DMA Done Masked Interrupt Value Description 0 A Timer B DMA done interrupt has not occurred or is masked. 1 An unmasked Timer B DMA done interrupt has occurred. This bit is cleared by writing a 1 to the DMABINT bit in the GPTMICR register. 12 reserved RO 0x0 11 TBMMIS RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B Match Masked Interrupt Value Description 0 A Timer B Mode Match interrupt has not occurred or is masked. 1 An unmasked Timer B Mode Match interrupt has occurred. This bit is cleared by writing a 1 to the TBMCINT bit in the GPTMICR register. June 18, 2014 999 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 10 CBEMIS RO 0 Description GPTM Timer B Capture Mode Event Masked Interrupt Value Description 0 A Capture B event interrupt has not occurred or is masked. 1 An unmasked Capture B event interrupt has occurred. This bit is cleared by writing a 1 to the CBECINT bit in the GPTMICR register. 9 CBMMIS RO 0 GPTM Timer B Capture Mode Match Masked Interrupt Value Description 0 A Capture B Mode Match interrupt has not occurred or is masked. 1 An unmasked Capture B Match interrupt has occurred. This bit is cleared by writing a 1 to the CBMCINT bit in the GPTMICR register. 8 TBTOMIS RO 0 GPTM Timer B Time-Out Masked Interrupt Value Description 0 A Timer B Time-Out interrupt has not occurred or is masked. 1 An unmasked Timer B Time-Out interrupt has occurred. This bit is cleared by writing a 1 to the TBTOCINT bit in the GPTMICR register. 7:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5 DMAAMIS RO 0 GPTM Timer A DMA Done Masked Interrupt Value Description 0 A Timer A DMA done interrupt has not occurred or is masked. 1 An unmasked Timer A DMA done interrupt has occurred. This bit is cleared by writing a 1 to the DMAAINT bit in the GPTMICR register. 4 TAMMIS RO 0 GPTM Timer A Match Masked Interrupt Value Description 0 A Timer A Mode Match interrupt has not occurred or is masked. 1 An unmasked Timer A Mode Match interrupt has occurred. This bit is cleared by writing a 1 to the TAMCINT bit in the GPTMICR register. 1000 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 RTCMIS RO 0 Description GPTM RTC Masked Interrupt Value Description 0 An RTC event interrupt has not occurred or is masked. 1 An unmasked RTC event interrupt has occurred. This bit is cleared by writing a 1 to the RTCCINT bit in the GPTMICR register. 2 CAEMIS RO 0 GPTM Timer A Capture Mode Event Masked Interrupt Value Description 0 A Capture A event interrupt has not occurred or is masked. 1 An unmasked Capture A event interrupt has occurred. This bit is cleared by writing a 1 to the CAECINT bit in the GPTMICR register. 1 CAMMIS RO 0 GPTM Timer A Capture Mode Match Masked Interrupt Value Description 0 A Capture A Mode Match interrupt has not occurred or is masked. 1 An unmasked Capture A Match interrupt has occurred. This bit is cleared by writing a 1 to the CAMCINT bit in the GPTMICR register. 0 TATOMIS RO 0 GPTM Timer A Time-Out Masked Interrupt Value Description 0 A Timer A Time-Out interrupt has not occurred or is masked. 1 An unmasked Timer A Time-Out interrupt has occurred. This bit is cleared by writing a 1 to the TATOCINT bit in the GPTMICR register. June 18, 2014 1001 Texas Instruments-Production Data General-Purpose Timers Register 9: GPTM Interrupt Clear (GPTMICR), offset 0x024 This register is used to clear the status bits in the GPTMRIS and GPTMMIS registers. Writing a 1 to a bit clears the corresponding bit in the GPTMRIS and GPTMMIS registers. GPTM Interrupt Clear (GPTMICR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x024 Type W1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 15 14 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 13 12 11 10 9 8 7 6 DMABINT reserved TBMCINT CBECINT CBMCINT TBTOCINT W1C 0 RO 0 W1C 0 W1C 0 W1C 0 Bit/Field Name Type Reset 31:14 reserved RO 0x0000 13 DMABINT W1C 0 W1C 0 reserved RO 0 RO 0 DMAAINT TAMCINT RTCCINT CAECINT CAMCINT TATOCINT W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B DMA Done Interrupt Clear Writing a 1 to this bit clears the DMABRIS bit in the GPTMRIS register and the DMABMIS bit in the GPTMMIS register. 12 reserved RO 0x0 11 TBMCINT W1C 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B Match Interrupt Clear Writing a 1 to this bit clears the TBMRIS bit in the GPTMRIS register and the TBMMIS bit in the GPTMMIS register. 10 CBECINT W1C 0 GPTM Timer B Capture Mode Event Interrupt Clear Writing a 1 to this bit clears the CBERIS bit in the GPTMRIS register and the CBEMIS bit in the GPTMMIS register. 9 CBMCINT W1C 0 GPTM Timer B Capture Mode Match Interrupt Clear Writing a 1 to this bit clears the CBMRIS bit in the GPTMRIS register and the CBMMIS bit in the GPTMMIS register. 8 TBTOCINT W1C 0 GPTM Timer B Time-Out Interrupt Clear Writing a 1 to this bit clears the TBTORIS bit in the GPTMRIS register and the TBTOMIS bit in the GPTMMIS register. 7:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1002 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 5 DMAAINT W1C 0 Description GPTM Timer A DMA Done Interrupt Clear Writing a 1 to this bit clears the DMAARIS bit in the GPTMRIS register and the DMAAMIS bit in the GPTMMIS register. 4 TAMCINT W1C 0 GPTM Timer A Match Interrupt Clear Writing a 1 to this bit clears the TAMRIS bit in the GPTMRIS register and the TAMMIS bit in the GPTMMIS register. 3 RTCCINT W1C 0 GPTM RTC Interrupt Clear Writing a 1 to this bit clears the RTCRIS bit in the GPTMRIS register and the RTCMIS bit in the GPTMMIS register. 2 CAECINT W1C 0 GPTM Timer A Capture Mode Event Interrupt Clear Writing a 1 to this bit clears the CAERIS bit in the GPTMRIS register and the CAEMIS bit in the GPTMMIS register. 1 CAMCINT W1C 0 GPTM Timer A Capture Mode Match Interrupt Clear Writing a 1 to this bit clears the CAMRIS bit in the GPTMRIS register and the CAMMIS bit in the GPTMMIS register. 0 TATOCINT W1C 0 GPTM Timer A Time-Out Raw Interrupt Writing a 1 to this bit clears the TATORIS bit in the GPTMRIS register and the TATOMIS bit in the GPTMMIS register. June 18, 2014 1003 Texas Instruments-Production Data General-Purpose Timers Register 10: GPTM Timer A Interval Load (GPTMTAILR), offset 0x028 When the timer is counting down, this register is used to load the starting count value into the timer. When the timer is counting up, this register sets the upper bound for the timeout event. When a GPTM is configured to one of the 32-bit modes, GPTMTAILR appears as a 32-bit register (the upper 16-bits correspond to the contents of the GPTM Timer B Interval Load (GPTMTBILR) register). In a 16-bit mode, the upper 16 bits of this register read as 0s and have no effect on the state of GPTMTBILR. GPTM Timer A Interval Load (GPTMTAILR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x028 Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 TAILR Type Reset TAILR Type Reset Bit/Field Name Type 31:0 TAILR RW Reset Description 0xFFFF.FFFF GPTM Timer A Interval Load Register Writing this field loads the counter for Timer A. A read returns the current value of GPTMTAILR. 1004 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: GPTM Timer B Interval Load (GPTMTBILR), offset 0x02C When the timer is counting down, this register is used to load the starting count value into the timer. When the timer is counting up, this register sets the upper bound for the timeout event. When a GPTM is configured to one of the 32-bit modes, the contents of bits 15:0 in this register are loaded into the upper 16 bits of the GPTMTAILR register. Reads from this register return the current value of Timer B and writes are ignored. In a 16-bit mode, bits 15:0 are used for the load value. Bits 31:16 are reserved in both cases. GPTM Timer B Interval Load (GPTMTBILR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x02C Type RW, reset 0x0000.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 TBILR Type Reset TBILR Type Reset Bit/Field Name Type 31:0 TBILR RW Reset Description 0x0000.FFFF GPTM Timer B Interval Load Register Writing this field loads the counter for Timer B. A read returns the current value of GPTMTBILR. When a 16/32-bit GPTM is in 32-bit mode, writes are ignored, and reads return the current value of GPTMTBILR. June 18, 2014 1005 Texas Instruments-Production Data General-Purpose Timers Register 12: GPTM Timer A Match (GPTMTAMATCHR), offset 0x030 This register is loaded with a match value. Interrupts can be generated when the timer value is equal to the value in this register in one-shot or periodic mode. In Edge-Count mode, this register along with GPTMTAILR, determines how many edge events are counted. The total number of edge events counted is equal to the value in GPTMTAILR minus this value. Note that in edge-count mode, when executing an up-count, the value of GPTMTnPR and GPTMTnILR must be greater than the value of GPTMTnPMR and GPTMTnMATCHR. In PWM mode, this value along with GPTMTAILR, determines the duty cycle of the output PWM signal. When a 16/32-bit GPTM is configured to one of the 32-bit modes, GPTMTAMATCHR appears as a 32-bit register (the upper 16-bits correspond to the contents of the GPTM Timer B Match (GPTMTBMATCHR) register). In a 16-bit mode, the upper 16 bits of this register read as 0s and have no effect on the state of GPTMTBMATCHR. GPTM Timer A Match (GPTMTAMATCHR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x030 Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 TAMR Type Reset TAMR Type Reset Bit/Field Name Type 31:0 TAMR RW Reset Description 0xFFFF.FFFF GPTM Timer A Match Register This value is compared to the GPTMTAR register to determine match events. 1006 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 13: GPTM Timer B Match (GPTMTBMATCHR), offset 0x034 This register is loaded with a match value. Interrupts can be generated when the timer value is equal to the value in this register in one-shot or periodic mode. In Edge-Count mode, this register along with GPTMTBILR determines how many edge events are counted. The total number of edge events counted is equal to the value in GPTMTBILR minus this value. Note that in edge-count mode, when executing an up-count, the value of GPTMTnPR and GPTMTnILR must be greater than the value of GPTMTnPMR and GPTMTnMATCHR. In PWM mode, this value along with GPTMTBILR, determines the duty cycle of the output PWM signal. When a GPTM is configured to one of the 32-bit modes, the contents of bits 15:0 in this register are loaded into the upper 16 bits of the GPTMTAMATCHR register. Reads from this register return the current match value of Timer B and writes are ignored. In a 16-bit mode, bits 15:0 are used for the match value. Bits 31:16 are reserved in both cases. GPTM Timer B Match (GPTMTBMATCHR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x034 Type RW, reset 0x0000.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 TBMR Type Reset TBMR Type Reset Bit/Field Name Type 31:0 TBMR RW Reset Description 0x0000.FFFF GPTM Timer B Match Register This value is compared to the GPTMTBR register to determine match events. June 18, 2014 1007 Texas Instruments-Production Data General-Purpose Timers Register 14: GPTM Timer A Prescale (GPTMTAPR), offset 0x038 This register allows software to extend the range of the timers when they are used individually. When in one-shot or periodic down count modes, this register acts as a true prescaler for the timer counter. When acting as a true prescaler, the prescaler counts down to 0 before the value in the GPTMTAR and GPTMTAV registers are incremented. In all other individual/split modes, this register is a linear extension of the upper range of the timer counter, holding bits 23:16 in the 16-bit modes of the 16/32-bit GPTM. GPTM Timer A Prescale (GPTMTAPR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x038 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 TAPSR RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0 7:0 TAPSR RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer A Prescale The register loads this value on a write. A read returns the current value of the register. For the 16/32-bit GPTM, this field contains the entire 8-bit prescaler. Refer to Table 13-5 on page 961 for more details and an example. 1008 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 15: GPTM Timer B Prescale (GPTMTBPR), offset 0x03C This register allows software to extend the range of the timers when they are used individually. When in one-shot or periodic down count modes, this register acts as a true prescaler for the timer counter. When acting as a true prescaler, the prescaler counts down to 0 before the value in the GPTMTBR and GPTMTBV registers are incremented. In all other individual/split modes, this register is a linear extension of the upper range of the timer counter, holding bits 23:16 in the 16-bit modes of the 16/32-bit GPTM. GPTM Timer B Prescale (GPTMTBPR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x03C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 TBPSR RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0 7:0 TBPSR RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM Timer B Prescale The register loads this value on a write. A read returns the current value of this register. For the 16/32-bit GPTM, this field contains the entire 8-bit prescaler. Refer to Table 13-5 on page 961 for more details and an example. June 18, 2014 1009 Texas Instruments-Production Data General-Purpose Timers Register 16: GPTM TimerA Prescale Match (GPTMTAPMR), offset 0x040 This register allows software to extend the range of the GPTMTAMATCHR when the timers are used individually. This register holds bits 23:16 in the 16-bit modes of the 16/32-bit GPTM. GPTM TimerA Prescale Match (GPTMTAPMR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x040 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 TAPSMR RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000 7:0 TAPSMR RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM TimerA Prescale Match This value is used alongside GPTMTAMATCHR to detect timer match events while using a prescaler. For the 16/32-bit GPTM, this field contains the entire 8-bit prescaler match value. 1010 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 17: GPTM TimerB Prescale Match (GPTMTBPMR), offset 0x044 This register allows software to extend the range of the GPTMTBMATCHR when the timers are used individually. This register holds bits 23:16 in the 16-bit modes of the 16/32-bit GPTM. GPTM TimerB Prescale Match (GPTMTBPMR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x044 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 TBPSMR RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000 7:0 TBPSMR RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. GPTM TimerB Prescale Match This value is used alongside GPTMTBMATCHR to detect timer match events while using a prescaler. June 18, 2014 1011 Texas Instruments-Production Data General-Purpose Timers Register 18: GPTM Timer A (GPTMTAR), offset 0x048 This register shows the current value of the Timer A counter in all cases except for Input Edge Count and Time modes. In the Input Edge Count mode, this register contains the number of edges that have occurred. In the Input Edge Time mode, this register contains the time at which the last edge event took place. Note: When an alternate clock source is enabled, a read of this register returns the current count -1. When a GPTM is configured to one of the 32-bit modes, GPTMTAR appears as a 32-bit register (the upper 16-bits correspond to the contents of the GPTM Timer B (GPTMTBR) register). In the16-bit Input Edge Count, Input Edge Time, and PWM modes, bits 15:0 contain the value of the counter and bits 23:16 contain the value of the prescaler, which is the upper 8 bits of the count. Bits 31:24 always read as 0. To read the value of the prescaler in 16-bit One-Shot and Periodic modes, read bits [23:16] in the GPTMTAV register. To read the value of the prescalar in periodic snapshot mode, read the Timer A Prescale Snapshot (GPTMTAPS) register. GPTM Timer A (GPTMTAR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x048 Type RO, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 TAR Type Reset RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 15 14 13 12 11 10 9 8 TAR Type Reset RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 Bit/Field Name Type 31:0 TAR RO RO 1 Reset RO 1 Description 0xFFFF.FFFF GPTM Timer A Register A read returns the current value of the GPTM Timer A Count Register, in all cases except for Input Edge Count and Time modes. In the Input Edge Count mode, this register contains the number of edges that have occurred. In the Input Edge Time mode, this register contains the time at which the last edge event took place. 1012 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: GPTM Timer B (GPTMTBR), offset 0x04C This register shows the current value of the Timer B counter in all cases except for Input Edge Count and Time modes. In the Input Edge Count mode, this register contains the number of edges that have occurred. In the Input Edge Time mode, this register contains the time at which the last edge event took place. Note: When an alternate clock source is enabled, a read of this register returns the current count -1. When a GPTM is configured to one of the 32-bit modes, the contents of bits 15:0 in this register are loaded into the upper 16 bits of the GPTMTAR register. Reads from this register return the current value of Timer B. In a 16-bit mode, bits 15:0 contain the value of the counter and bits 23:16 contain the value of the prescaler in Input Edge Count, Input Edge Time, and PWM modes, which is the upper 8 bits of the count. Bits 31:24 always read as 0. To read the value of the prescaler in 16-bit One-Shot and Periodic modes, read bits [23:16] in the GPTMTBV register. To read the value of the prescalar in periodic snapshot mode, read the Timer B Prescale Snapshot (GPTMTBPS) register. GPTM Timer B (GPTMTBR) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x04C Type RO, reset 0x0000.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 TBR Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 TBR Type Reset RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 Bit/Field Name Type 31:0 TBR RO RO 1 Reset RO 1 Description 0x0000.FFFF GPTM Timer B Register A read returns the current value of the GPTM Timer B Count Register, in all cases except for Input Edge Count and Time modes. In the Input Edge Count mode, this register contains the number of edges that have occurred. In the Input Edge Time mode, this register contains the time at which the last edge event took place. June 18, 2014 1013 Texas Instruments-Production Data General-Purpose Timers Register 20: GPTM Timer A Value (GPTMTAV), offset 0x050 When read, this register shows the current, free-running value of Timer A in all modes. Software can use this value to determine the time elapsed between an interrupt and the ISR entry when using the snapshot feature with the periodic operating mode. When written, the value written into this register is loaded into the GPTMTAR register on the next clock cycle. Note: When an alternate clock source is enabled, a read of this register returns the current count -1. When a 16/32-bit GPTM is configured to one of the 32-bit modes, GPTMTAV appears as a 32-bit register (the upper 16-bits correspond to the contents of the GPTM Timer B Value (GPTMTBV) register). In a 16-bit mode, bits 15:0 contain the value of the counter and bits 23:16 contain the current, free-running value of the prescaler, which is the upper 8 bits of the count in Input Edge Count, Input Edge Time, PWM and one-shot or periodic up count modes. In one-shot or periodic down count modes, the prescaler stored in 23:16 is a true prescaler, meaning bits 23:16 count down before decrementing the value in bits 15:0. The prescaler in bits 31:24 always reads as 0. GPTM Timer A Value (GPTMTAV) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x050 Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 TAV Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 TAV Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 Bit/Field Name Type 31:0 TAV RW RW 1 Reset RW 1 Description 0xFFFF.FFFF GPTM Timer A Value A read returns the current, free-running value of Timer A in all modes. When written, the value written into this register is loaded into the GPTMTAR register on the next clock cycle. Note: In 16-bit mode, only the lower 16-bits of the GPTMTAV register can be written with a new value. Writes to the prescaler bits have no effect. 1014 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 21: GPTM Timer B Value (GPTMTBV), offset 0x054 When read, this register shows the current, free-running value of Timer B in all modes. Software can use this value to determine the time elapsed between an interrupt and the ISR entry. When written, the value written into this register is loaded into the GPTMTBR register on the next clock cycle. Note: When an alternate clock source is enabled, a read of this register returns the current count -1. When a 16/32-bit GPTM is configured to one of the 32-bit modes, the contents of bits 15:0 in this register are loaded into the upper 16 bits of the GPTMTAV register. Reads from this register return the current free-running value of Timer B. In a 16-bit mode, bits 15:0 contain the value of the counter and bits 23:16 contain the current, free-running value of the prescaler, which is the upper 8 bits of the count in Input Edge Count, Input Edge Time, PWM and one-shot or periodic up count modes. In one-shot or periodic down count modes, the prescaler stored in 23:16 is a true prescaler, meaning bits 23:16 count down before decrementing the value in bits 15:0. The prescaler in bits 31:24 always reads as 0. GPTM Timer B Value (GPTMTBV) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x054 Type RW, reset 0x0000.FFFF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 TBV Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 TBV Type Reset RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 Bit/Field Name Type 31:0 TBV RW RW 1 Reset RW 1 Description 0x0000.FFFF GPTM Timer B Value A read returns the current, free-running value of Timer A in all modes. When written, the value written into this register is loaded into the GPTMTAR register on the next clock cycle. Note: In 16-bit mode, only the lower 16-bits of the GPTMTBV register can be written with a new value. Writes to the prescaler bits have no effect. June 18, 2014 1015 Texas Instruments-Production Data General-Purpose Timers Register 22: GPTM RTC Predivide (GPTMRTCPD), offset 0x058 This register provides the current RTC predivider value when the timer is operating in RTC mode. Software must perform an atomic access with consecutive reads of the GPTMTAR, GPTMTBR, and GPTMRTCPD registers. Note: When an alternate clock source is enabled, a read of this register returns the current count -1. GPTM RTC Predivide (GPTMRTCPD) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x058 Type RO, reset 0x0000.7FFF 31 30 29 28 27 26 25 24 23 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 reserved Type Reset RTCPD Type Reset Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15:0 RTCPD RO Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000.7FFF RTC Predivide Counter Value The current RTC predivider value when the timer is operating in RTC mode. This field has no meaning in other timer modes. 1016 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 23: GPTM Timer A Prescale Snapshot (GPTMTAPS), offset 0x05C For 16-/32-bit wide GPTM, this register shows the current value of the Timer A prescaler for periodic snapshot mode. GPTM Timer A Prescale Snapshot (GPTMTAPS) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x05C Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 PSS Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 PSS RO 0x0000 GPTM Timer A Prescaler Snapshot A read returns the current value of the GPTM Timer A Prescaler. June 18, 2014 1017 Texas Instruments-Production Data General-Purpose Timers Register 24: GPTM Timer B Prescale Snapshot (GPTMTBPS), offset 0x060 For 16-/32-bit wide GPTM, this register shows the current value of the Timer B prescaler for periodic snapshot mode. GPTM Timer B Prescale Snapshot (GPTMTBPS) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x060 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 PSS Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 PSS RO 0x0000 GPTM Timer A Prescaler Value A read returns the current value of the GPTM Timer A Prescaler. 1018 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 25: GPTM DMA Event (GPTMDMAEV), offset 0x06C This register allows software to enable/disable GPTM DMA trigger events. Setting a bit enables the corresponding DMA trigger, while clearing a bit disables it. GPTM DMA Event (GPTMDMAEV) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x06C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 reserved TBMDMAEN CBEDMAEN CBMDMAEN TBTODMAEN RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 TAMDMAEN RTCDMAEN CAEDMAEN CAMDMAEN TATODMAEN RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 TBMDMAEN RW 0 GPTM B Mode Match Event DMA Trigger Enable When this bit is enabled, a Timer B dma_req signal is sent to the µDMA when a mode match has occurred. Value Description 10 CBEDMAEN RW 0 0 Timer B Mode Match DMA trigger is disabled. 1 Timer B DMA Mode Match trigger is enabled. GPTM B Capture Event DMA Trigger Enable When this bit is enabled, a Timer B dma_req signal is sent to the µDMA when a capture event has occurred. Value Description 9 CBMDMAEN RW 0 0 Timer B Capture Event DMA trigger is disabled. 1 Timer B Capture Event DMA trigger is enabled. GPTM B Capture Match Event DMA Trigger Enable When this bit is enabled, a Timer B dma_req signal is sent to the µDMA when a capture match event has occurred. Value Description 0 Timer B Capture Match DMA trigger is disabled. 1 Timer B Capture Match DMA trigger is enabled. June 18, 2014 1019 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 8 TBTODMAEN RW 0 Description GPTM B Time-Out Event DMA Trigger Enable When this bit is enabled, a Timer B dma_req signal is sent to the µDMA on a time-out event. Value Description 0 Timer B Time-Out DMA trigger is disabled. 1 Timer B Time-Out DMA trigger is enabled. 7:5 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 TAMDMAEN RW 0 GPTM A Mode Match Event DMA Trigger Enable When this bit is enabled, a Timer A dma_req signal is sent to the µDMA when a mode match has occurred. Value Description 3 RTCDMAEN RW 0 0 Timer A Mode Match DMA trigger is disabled. 1 Timer A DMA Mode Match trigger is enabled. GPTM A RTC Match Event DMA Trigger Enable When this bit is enabled, a Timer A dma_req signal is sent to the µDMA when a RTC match has occurred. Value Description 2 CAEDMAEN RW 0 0 Timer A RTC Match DMA trigger is disabled. 1 Timer A RTC Match DMA trigger is enabled. GPTM A Capture Event DMA Trigger Enable When this bit is enabled, a Timer A dma_req signal is sent to the µDMA when a capture event has occurred. Value Description 1 CAMDMAEN RW 0 0 Timer A Capture Event DMA trigger is disabled. 1 Timer A Capture Event DMA trigger is enabled. GPTM A Capture Match Event DMA Trigger Enable When this bit is enabled, a Timer A dma_req signal is sent to the µDMA when a capture match event has occurred. Value Description 0 Timer A Capture Match DMA trigger is disabled. 1 Timer A Capture Match DMA trigger is enabled. 1020 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 TATODMAEN RW 0 Description GPTM A Time-Out Event DMA Trigger Enable When this bit is enabled, a Timer A dma_req signal is sent to the µDMA on a time-out event. Value Description 0 Timer A Time-Out DMA trigger is disabled. 1 Timer A Time-Out DMA trigger is enabled. June 18, 2014 1021 Texas Instruments-Production Data General-Purpose Timers Register 26: GPTM ADC Event (GPTMADCEV), offset 0x070 This register allows software to enable/disable GPTM ADC trigger events. Setting a bit enables the corresponding ADC trigger, while clearing a bit disables it. GPTM ADC Event (GPTMADCEV) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0x070 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 reserved TBMADCEN CBEADCEN CBMADCEN TBTOADCEN RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 TAMADCEN RTCADCEN CAEADCEN CAMADCEN TATOADCEN RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 TBMADCEN RW 0 GPTM B Mode Match Event ADC Trigger Enable When this bit is enabled, a a trigger pulse is sent to the ADC when a mode match has occurred. Value Description 10 CBEADCEN RW 0 0 Timer B Mode Match ADC trigger is disabled. 1 Timer B Mode Match ADC trigger is enabled. GPTM B Capture Event ADC Trigger Enable When this bit is enabled, a trigger pulse is sent to the ADC when a capture event has occurred. Value Description 9 CBMADCEN RW 0 0 Timer B Capture Event ADC trigger is disabled. 1 Timer B Capture Event ADC trigger is enabled. GPTM B Capture Match Event ADC Trigger Enable When this bit is enabled, a trigger signal is sent to the ADC when a capture match event has occurred. Value Description 0 Timer B Capture Match ADC trigger is disabled. 1 Timer B Capture Match ADC trigger is enabled. 1022 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 8 TBTOADCEN RW 0 Description GPTM B Time-Out Event ADC Trigger Enable When this bit is enabled, a trigger signal is sent to the ADC on a time-out event. Value Description 0 Timer B Time-Out ADC trigger is disabled. 1 Timer B Time-Out ADC trigger is enabled. 7:5 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 TAMADCEN RW 0 GPTM A Mode Match Event ADC Trigger Enable When this bit is enabled, a a trigger pulse is sent to the ADC when a mode match has occurred. Value Description 3 RTCADCEN RW 0 0 Timer A Mode Match ADC trigger is disabled. 1 Timer A Mode Match ADC trigger is enabled. GPTM RTC Match Event ADC Trigger Enable When this bit is enabled, a trigger signal is sent to the ADC when a RTC match has occurred. Value Description 2 CAEADCEN RW 0 0 Timer A RTC Match ADC trigger is disabled. 1 Timer A RTC Match ADC trigger is enabled. GPTM A Capture Event ADC Trigger Enable When this bit is enabled, a trigger pulse is sent to the ADC when a capture event has occurred. Value Description 1 CAMADCEN RW 0 0 Timer A Capture Event ADC trigger is disabled. 1 Timer A Capture Event ADC trigger is enabled. GPTM A Capture Match Event ADC Trigger Enable When this bit is enabled, a trigger signal is sent to the ADC when a capture match event has occurred. Value Description 0 Timer A Capture Match ADC trigger is disabled. 1 Timer A Capture Match ADC trigger is enabled. June 18, 2014 1023 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset 0 TATOADCEN RW 0 Description GPTM A Time-Out Event ADC Trigger Enable When this bit is enabled, a trigger signal is sent to the ADC on a time-out event. Value Description 0 Timer A Time-Out Event ADC trigger is disabled. 1 Timer A Time-Out Event ADC trigger is enabled. 1024 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 27: GPTM Peripheral Properties (GPTMPP), offset 0xFC0 The GPTMPP register provides information regarding the properties of the General-Purpose Timer module. GPTM Peripheral Properties (GPTMPP) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0xFC0 Type RO, reset 0x0000.0070 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 reserved Type Reset RO 0 RO 0 RO 0 RO 0 ALTCLK SYNCCNT CHAIN RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:7 reserved RO 0 6 ALTCLK RO 0x1 RO 0 RO 0 RO 1 RO 1 RO 1 SIZE RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Alternate Clock Source Value Description 5 SYNCCNT RO 0x1 0 The alternate clock source (ALTCLK) is not available to the Timer module. 1 The alternate clock source (ALTCLK) is available to the Timer module. Synchronize Start Value Description 4 CHAIN RO 0x1 0 Timer is not capable of synchronizing the counter value with other GPTimers. 1 Timer is capable of synchronizing the counter value with other Timers. Chain with Other Timers Value Description 0 Timer is not capable of chaining with the previously numbered Timer. 1 Timer is capable of chaining with the previously numbered Timer. Note that although this bit is set for Timer 0A, this timer cannot chain because there is not a previously numbered Timer. June 18, 2014 1025 Texas Instruments-Production Data General-Purpose Timers Bit/Field Name Type Reset Description 3:0 SIZE RO 0x0 Count Size Value Description 0 Timer A and Timer B counters are 16 bits each with an 8-bit prescale counter. 1 Timer A and Timer B counters are 32 bits each with a 16-bit prescale counter. 1026 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 28: GPTM Clock Configuration (GPTMCC), offset 0xFC8 The GPTMCC register controls the clock source for the General-Purpose Timer module. Note: When the ALTCLK bit is set in the GPTMCC register to enable using the alternate clock source, the synchronization imposes restrictions on the starting count value (down-count), terminal value (up-count) and the match value. This restriction applies to all modes of operation. Each event must be spaced by 4 Timer (ALTCLK) clock periods + 2 system clock periods. If some events do not meet this requirement, then it is possible that the timer block may need to be reset for correct functionality to be restored. Example: ALTCLK= TPIOSC = 62.5ns (16Mhz Trimmed) Thclk = 1us (1Mhz) 4*62.5ns + 2*1us = 2.25us 2.25us/62.5ns = 36 or 0x23 The minimum values for the periodic or one-shot with a match interrupt enabled are: GPTMTAMATCHR = 0x23 GPTMTAILR = 0x46 GPTM Clock Configuration (GPTMCC) 16/32-bit Timer 0 base: 0x4003.0000 16/32-bit Timer 1 base: 0x4003.1000 16/32-bit Timer 2 base: 0x4003.2000 16/32-bit Timer 3 base: 0x4003.3000 16/32-bit Timer 4 base: 0x4003.4000 16/32-bit Timer 5 base: 0x4003.5000 16/32-bit Timer 6 base: 0x400E.0000 16/32-bit Timer 7 base: 0x400E.1000 Offset 0xFC8 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type 31:1 reserved RO 0 ALTCLK RW RO 0 Reset RO 0 0 ALTCLK RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 Description 0x0000.0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 Alternate Clock Source Value Description 0 System clock (based on clock source and divisor factor programmed in RSCLKCFG register in the System Control Module) 1 Alternate clock source as defined by ALTCLKCFG register in System Control Module. June 18, 2014 1027 Texas Instruments-Production Data Watchdog Timers 14 Watchdog Timers A watchdog timer can generate a non-maskable interrupt (NMI), a regular interrupt or a reset when a time-out value is reached. The watchdog timer is used to regain control when a system has failed due to a software error or due to the failure of an external device to respond in the expected way. The TM4C1294NCPDT microcontroller has two Watchdog Timer Modules, one module is clocked by the system clock (Watchdog Timer 0) and the other (Watchdog Timer 1) is clocked by the clock source programmed in the ALTCLK field of the Alternate Clock Configuration (ALTCLKCFG) register, System Control offset 0x138. The two modules are identical except that WDT1 is in a different clock domain, and therefore requires synchronizers. As a result, WDT1 has a bit defined in the Watchdog Timer Control (WDTCTL) register to indicate when a write to a WDT1 register is complete. Software can use this bit to ensure that the previous access has completed before starting the next access. The TM4C1294NCPDT controller has two Watchdog Timer modules with the following features: ■ 32-bit down counter with a programmable load register ■ Separate watchdog clock with an enable ■ Programmable interrupt generation logic with interrupt masking and optional NMI function ■ Lock register protection from runaway software ■ Reset generation logic with an enable/disable ■ User-enabled stalling when the microcontroller asserts the CPU Halt flag during debug The Watchdog Timer can be configured to generate an interrupt to the controller on its first time-out, and to generate a reset signal on its second time-out. Once the Watchdog Timer has been configured, the lock register can be written to prevent the timer configuration from being inadvertently altered. 1028 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 14.1 Block Diagram Figure 14-1. WDT Module Block Diagram WDTLOAD Control / Clock / Interrupt Generation WDTCTL WDTICR Interrupt/NMI WDTRIS 32-Bit Down Counter WDTMIS 0x0000.0000 WDTLOCK System Clock/ PIOSC WDTTEST Comparator WDTVALUE Identification Registers 14.2 WDTPCellID0 WDTPeriphID0 WDTPeriphID4 WDTPCellID1 WDTPeriphID1 WDTPeriphID5 WDTPCellID2 WDTPeriphID2 WDTPeriphID6 WDTPCellID3 WDTPeriphID3 WDTPeriphID7 Functional Description The Watchdog Timer module generates the first time-out signal when the 32-bit counter reaches the zero state after being enabled; enabling the counter also enables the watchdog timer interrupt. The watchdog interrupt can be programmed to be a non-maskable interrupt (NMI) using the INTTYPE bit in the WDTCTL register. After the first time-out event, the 32-bit counter is re-loaded with the value of the Watchdog Timer Load (WDTLOAD) register, and the timer resumes counting down from that value. Once the Watchdog Timer has been configured, the Watchdog Timer Lock (WDTLOCK) register is written, which prevents the timer configuration from being inadvertently altered by software. If the timer counts down to its zero state again before the first time-out interrupt is cleared, and the reset signal has been enabled by setting the RESEN bit in the WDTCTL register, the Watchdog timer asserts its reset signal to the system. If the interrupt is cleared before the 32-bit counter reaches its second time-out, the 32-bit counter is loaded with the value in the WDTLOAD register, and counting resumes from that value. If WDTLOAD is written with a new value while the Watchdog Timer counter is counting, then the counter is loaded with the new value and continues counting. June 18, 2014 1029 Texas Instruments-Production Data Watchdog Timers Writing to WDTLOAD does not clear an active interrupt. An interrupt must be specifically cleared by writing to the Watchdog Interrupt Clear (WDTICR) register. The Watchdog module interrupt and reset generation can be enabled or disabled as required. When the interrupt is re-enabled, the 32-bit counter is preloaded with the load register value and not its last state. The watchdog timer is disabled by default out of reset. To achieve maximum watchdog protection of the device, the watchdog timer can be enabled at the start of the reset vector. 14.2.1 Register Access Timing Because the Watchdog Timer 1 module has an independent clocking domain, its registers must be written with a timing gap between accesses. Software must guarantee that this delay is inserted between back-to-back writes to WDT1 registers or between a write followed by a read to the registers. The timing for back-to-back reads from the WDT1 module has no restrictions. The WRC bit in the Watchdog Control (WDTCTL) register for WDT1 indicates that the required timing gap has elapsed. This bit is cleared on a write operation and set once the write completes, indicating to software that another write or read may be started safely. Software should poll WDTCTL for WRC=1 prior to accessing another register. Note that WDT0 does not have this restriction as it runs off the system clock. 14.3 Initialization and Configuration To use the WDT, its peripheral clock must be enabled by setting the Rn bit in the Watchdog Timer Run Mode Clock Gating Control (RCGCWD) register, see page 379. The Watchdog Timer is configured using the following sequence: 1. Load the WDTLOAD register with the desired timer load value. 2. If WDT1, wait for the WRC bit in the WDTCTL register to be set. 3. Set the INTEN bit (if interrupts are required) or the RESEN bit (if a reset is required after two timeouts) in the WDTCTL register. The Watchdog Timer starts when either of them is enabled. If software requires that all of the watchdog registers are locked, the Watchdog Timer module can be fully locked by writing any value to the WDTLOCK register. To unlock the Watchdog Timer, write a value of 0x1ACC.E551. To service the watchdog, periodically reload the count value into the WDTLOAD register to restart the count. The interrupt can be enabled using the INTEN bit in the WDTCTL register to allow the processor to attempt corrective action if the watchdog is not serviced often enough. The RESEN bit in WDTCTL can be set so that the system resets if the failure is not recoverable using the ISR. Note: 14.4 The application should be sure not to modify the ALTCLK encoding in the ALTCLKCFG register while the WDT1 is enabled and running. Register Map Table 14-1 on page 1031 lists the Watchdog registers. The offset listed is a hexadecimal increment to the register's address, relative to the Watchdog Timer base address: ■ WDT0: 0x4000.0000 ■ WDT1: 0x4000.1000 1030 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Note that the Watchdog Timer module clock must be enabled before the registers can be programmed (see page 379). Table 14-1. Watchdog Timers Register Map Description See page 0xFFFF.FFFF Watchdog Load 1032 RO 0xFFFF.FFFF Watchdog Value 1033 WDTCTL RW 0x0000.0000 (WDT0) 0x8000.0000 (WDT1) Watchdog Control 1034 0x00C WDTICR WO - Watchdog Interrupt Clear 1036 0x010 WDTRIS RO 0x0000.0000 Watchdog Raw Interrupt Status 1037 0x014 WDTMIS RO 0x0000.0000 Watchdog Masked Interrupt Status 1038 0x418 WDTTEST RW 0x0000.0000 Watchdog Test 1039 0xC00 WDTLOCK RW 0x0000.0000 Watchdog Lock 1040 0xFD0 WDTPeriphID4 RO 0x0000.0000 Watchdog Peripheral Identification 4 1041 0xFD4 WDTPeriphID5 RO 0x0000.0000 Watchdog Peripheral Identification 5 1042 0xFD8 WDTPeriphID6 RO 0x0000.0000 Watchdog Peripheral Identification 6 1043 0xFDC WDTPeriphID7 RO 0x0000.0000 Watchdog Peripheral Identification 7 1044 0xFE0 WDTPeriphID0 RO 0x0000.0005 Watchdog Peripheral Identification 0 1045 0xFE4 WDTPeriphID1 RO 0x0000.0018 Watchdog Peripheral Identification 1 1046 0xFE8 WDTPeriphID2 RO 0x0000.0018 Watchdog Peripheral Identification 2 1047 0xFEC WDTPeriphID3 RO 0x0000.0001 Watchdog Peripheral Identification 3 1048 0xFF0 WDTPCellID0 RO 0x0000.000D Watchdog PrimeCell Identification 0 1049 0xFF4 WDTPCellID1 RO 0x0000.00F0 Watchdog PrimeCell Identification 1 1050 0xFF8 WDTPCellID2 RO 0x0000.0006 Watchdog PrimeCell Identification 2 1051 0xFFC WDTPCellID3 RO 0x0000.00B1 Watchdog PrimeCell Identification 3 1052 Offset Name Type Reset 0x000 WDTLOAD RW 0x004 WDTVALUE 0x008 14.5 Register Descriptions The remainder of this section lists and describes the WDT registers, in numerical order by address offset. June 18, 2014 1031 Texas Instruments-Production Data Watchdog Timers Register 1: Watchdog Load (WDTLOAD), offset 0x000 This register is the 32-bit interval value used by the 32-bit counter. When this register is written, the value is immediately loaded and the counter restarts counting down from the new value. If the WDTLOAD register is loaded with 0x0000.0000, an interrupt is immediately generated. Watchdog Load (WDTLOAD) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0x000 Type RW, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 15 14 13 12 11 10 9 8 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 23 22 21 20 19 18 17 16 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 WDTLOAD Type Reset WDTLOAD Type Reset Bit/Field Name Type 31:0 WDTLOAD RW Reset RW 1 Description 0xFFFF.FFFF Watchdog Load Value 1032 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: Watchdog Value (WDTVALUE), offset 0x004 This register contains the current count value of the timer. Watchdog Value (WDTVALUE) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0x004 Type RO, reset 0xFFFF.FFFF 31 30 29 28 27 26 25 24 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 15 14 13 12 11 10 9 8 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 23 22 21 20 19 18 17 16 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 7 6 5 4 3 2 1 0 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 RO 1 WDTVALUE Type Reset WDTVALUE Type Reset Bit/Field Name Type 31:0 WDTVALUE RO Reset RO 1 Description 0xFFFF.FFFF Watchdog Value Current value of the 32-bit down counter. June 18, 2014 1033 Texas Instruments-Production Data Watchdog Timers Register 3: Watchdog Control (WDTCTL), offset 0x008 This register is the watchdog control register. The watchdog timer can be configured to generate a reset signal (on second time-out) or an interrupt on time-out. When the watchdog interrupt has been enabled by setting the INTEN bit, all subsequent writes to the INTEN bit are ignored. The only mechanisms that can re-enable writes to this bit are a hardware reset or a software reset initiated by setting the appropriate bit in the Watchdog Timer Software Reset (SRWD) register. Important: Because the Watchdog Timer 1 module has an independent clocking domain, its registers must be written with a timing gap between accesses. Software must guarantee that this delay is inserted between back-to-back writes to WDT1 registers or between a write followed by a read to the registers. The timing for back-to-back reads from the WDT1 module has no restrictions. The WRC bit in the Watchdog Control (WDTCTL) register for WDT1 indicates that the required timing gap has elapsed. This bit is cleared on a write operation and set once the write completes, indicating to software that another write or read may be started safely. Software should poll WDTCTL for WRC=1 prior to accessing another register. Note that WDT0 does not have this restriction as it runs off the system clock and therefore does not have a WRC bit. Watchdog Control (WDTCTL) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0x008 Type RW, reset 0x0000.0000 (WDT0) and 0x8000.0000 (WDT1) 31 30 29 28 27 26 25 24 22 21 20 19 18 17 16 RO 1 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 INTTYPE RESEN INTEN RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 WRC Type Reset 23 reserved reserved Type Reset RO 0 Bit/Field Name Type Reset 31 WRC RO 1 Description Write Complete The WRC values are defined as follows: Value Description 0 A write access to one of the WDT1 registers is in progress. 1 A write access is not in progress, and WDT1 registers can be read or written. Note: 30:3 reserved RO 0x000.000 This bit is reserved for WDT0 and has a reset value of 0. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1034 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2 INTTYPE RW 0 Description Watchdog Interrupt Type The INTTYPE values are defined as follows: Value Description 1 RESEN RW 0 0 Watchdog interrupt is a standard interrupt. 1 Watchdog interrupt is a non-maskable interrupt. Watchdog Reset Enable The RESEN values are defined as follows: Value Description 0 Disabled. 1 Enable the Watchdog module reset output. Setting this bit enables the Watchdog Timer. 0 INTEN RW 0 Watchdog Interrupt Enable The INTEN values are defined as follows: Value Description 0 Interrupt event disabled. Once this bit is set, it can only be cleared by a hardware reset or a software reset initiated by setting the appropriate bit in the Watchdog Timer Software Reset (SRWD) register. 1 Interrupt event enabled. Once enabled, all writes are ignored. Setting this bit enables the Watchdog Timer. June 18, 2014 1035 Texas Instruments-Production Data Watchdog Timers Register 4: Watchdog Interrupt Clear (WDTICR), offset 0x00C This register is the interrupt clear register. A write of any value to this register clears the Watchdog interrupt and reloads the 32-bit counter from the WDTLOAD register. Write to this register when a watchdog time-out interrupt has occurred to properly service the Watchdog. Value for a read or reset is indeterminate. Note: Locking the watchdog registers by using the WDTLOCK register does not affect the WDTICR register and allows interrupts to always be serviced. Thus, a write at any time of the WDTICR register clears the WDTMIS register and reloads the 32-bit counter from the WDTLOAD register. The WDTICR register should only be written when interrupts have triggered and need to be serviced. Watchdog Interrupt Clear (WDTICR) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0x00C Type WO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WDTINTCLR Type Reset WO - WO - WO - WO - WO - WO - WO - 15 14 13 12 11 10 9 WO - WO - WO - WO - WO - WO - WO - WO - WO - 8 7 6 5 4 3 2 1 0 WO - WO - WO - WO - WO - WO - WO - WDTINTCLR Type Reset WO - WO - WO - WO - WO - WO - WO - Bit/Field Name Type Reset 31:0 WDTINTCLR WO - WO - WO - Description Watchdog Interrupt Clear A write of any value to this register clears the Watchdog interrupt and reloads the 32-bit counter from the WDTLOAD register. Write to this register when a watchdog time-out interrupt has occurred to properly service the Watchdog. Value for a read or reset is indeterminate. 1036 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: Watchdog Raw Interrupt Status (WDTRIS), offset 0x010 This register is the raw interrupt status register. Watchdog interrupt events can be monitored via this register if the controller interrupt is masked. Watchdog Raw Interrupt Status (WDTRIS) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0x010 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 WDTRIS RO 0 RO 0 WDTRIS RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog Raw Interrupt Status Value Description 0 The watchdog has not timed out. 1 A watchdog time-out event has occurred. June 18, 2014 1037 Texas Instruments-Production Data Watchdog Timers Register 6: Watchdog Masked Interrupt Status (WDTMIS), offset 0x014 This register is the masked interrupt status register. The value of this register is the logical AND of the raw interrupt bit and the Watchdog interrupt enable bit. Watchdog Masked Interrupt Status (WDTMIS) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0x014 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 WDTMIS RO 0 RO 0 WDTMIS RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog Masked Interrupt Status Value Description 0 The watchdog has not timed out or the watchdog timer interrupt is masked. 1 A watchdog time-out event has been signalled to the interrupt controller. 1038 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 7: Watchdog Test (WDTTEST), offset 0x418 This register provides user-enabled stalling when the microcontroller asserts the CPU halt flag during debug. Watchdog Test (WDTTEST) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0x418 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 STALL Bit/Field Name Type Reset 31:9 reserved RO 0x0000.00 8 STALL RW 0 RW 0 reserved Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog Stall Enable Value Description 7:0 reserved RO 0x00 0 The watchdog timer continues counting if the microcontroller is stopped with a debugger. 1 If the microcontroller is stopped with a debugger, the watchdog timer stops counting. Once the microcontroller is restarted, the watchdog timer resumes counting. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1039 Texas Instruments-Production Data Watchdog Timers Register 8: Watchdog Lock (WDTLOCK), offset 0xC00 Writing 0x1ACC.E551 to the WDTLOCK register enables write access to all other registers. Writing any other value to the WDTLOCK register re-enables the locked state for register writes to all the other registers, except for the Watchdog Test (WDTTEST) register. Reading the WDTLOCK register returns the lock status rather than the 32-bit value written. Therefore, when write accesses are disabled, reading the WDTLOCK register returns 0x0000.0001 (when locked; otherwise, the returned value is 0x0000.0000 (unlocked)). Watchdog Lock (WDTLOCK) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xC00 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 WDTLOCK Type Reset WDTLOCK Type Reset Bit/Field Name Type 31:0 WDTLOCK RW Reset RW 0 Description 0x0000.0000 Watchdog Lock A write of the value 0x1ACC.E551 unlocks the watchdog registers for write access. A write of any other value reapplies the lock, preventing any register updates, except for the WDTTEST register. Avoid writes to the WDTTEST register when the watchdog registers are locked. A read of this register returns the following values: Value Description 0x0000.0001 Locked 0x0000.0000 Unlocked 1040 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 9: Watchdog Peripheral Identification 4 (WDTPeriphID4), offset 0xFD0 The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 4 (WDTPeriphID4) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFD0 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset PID4 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID4 RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. WDT Peripheral ID Register [7:0] June 18, 2014 1041 Texas Instruments-Production Data Watchdog Timers Register 10: Watchdog Peripheral Identification 5 (WDTPeriphID5), offset 0xFD4 The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 5 (WDTPeriphID5) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFD4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID5 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID5 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. WDT Peripheral ID Register [15:8] 1042 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: Watchdog Peripheral Identification 6 (WDTPeriphID6), offset 0xFD8 The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 6 (WDTPeriphID6) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFD8 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID6 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID6 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. WDT Peripheral ID Register [23:16] June 18, 2014 1043 Texas Instruments-Production Data Watchdog Timers Register 12: Watchdog Peripheral Identification 7 (WDTPeriphID7), offset 0xFDC The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 7 (WDTPeriphID7) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFDC Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID7 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID7 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. WDT Peripheral ID Register [31:24] 1044 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 13: Watchdog Peripheral Identification 0 (WDTPeriphID0), offset 0xFE0 The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 0 (WDTPeriphID0) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFE0 Type RO, reset 0x0000.0005 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 1 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID0 RO 0x05 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog Peripheral ID Register [7:0] June 18, 2014 1045 Texas Instruments-Production Data Watchdog Timers Register 14: Watchdog Peripheral Identification 1 (WDTPeriphID1), offset 0xFE4 The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 1 (WDTPeriphID1) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFE4 Type RO, reset 0x0000.0018 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 1 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID1 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID1 RO 0x18 RO 0 RO 0 RO 0 RO 0 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog Peripheral ID Register [15:8] 1046 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 15: Watchdog Peripheral Identification 2 (WDTPeriphID2), offset 0xFE8 The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 2 (WDTPeriphID2) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFE8 Type RO, reset 0x0000.0018 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 1 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID2 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID2 RO 0x18 RO 0 RO 0 RO 0 RO 0 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog Peripheral ID Register [23:16] June 18, 2014 1047 Texas Instruments-Production Data Watchdog Timers Register 16: Watchdog Peripheral Identification 3 (WDTPeriphID3), offset 0xFEC The WDTPeriphIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog Peripheral Identification 3 (WDTPeriphID3) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFEC Type RO, reset 0x0000.0001 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID3 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID3 RO 0x01 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog Peripheral ID Register [31:24] 1048 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 17: Watchdog PrimeCell Identification 0 (WDTPCellID0), offset 0xFF0 The WDTPCellIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog PrimeCell Identification 0 (WDTPCellID0) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFF0 Type RO, reset 0x0000.000D 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 RO 1 reserved Type Reset reserved Type Reset CID0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID0 RO 0x0D Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog PrimeCell ID Register [7:0] June 18, 2014 1049 Texas Instruments-Production Data Watchdog Timers Register 18: Watchdog PrimeCell Identification 1 (WDTPCellID1), offset 0xFF4 The WDTPCellIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog PrimeCell Identification 1 (WDTPCellID1) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFF4 Type RO, reset 0x0000.00F0 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 1 RO 1 RO 1 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset CID1 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID1 RO 0xF0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog PrimeCell ID Register [15:8] 1050 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: Watchdog PrimeCell Identification 2 (WDTPCellID2), offset 0xFF8 The WDTPCellIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog PrimeCell Identification 2 (WDTPCellID2) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFF8 Type RO, reset 0x0000.0006 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 0 reserved Type Reset reserved Type Reset CID2 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID2 RO 0x06 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog PrimeCell ID Register [23:16] June 18, 2014 1051 Texas Instruments-Production Data Watchdog Timers Register 20: Watchdog PrimeCell Identification 3 (WDTPCellID3 ), offset 0xFFC The WDTPCellIDn registers are hard-coded and the fields within the register determine the reset value. Watchdog PrimeCell Identification 3 (WDTPCellID3) WDT0 base: 0x4000.0000 WDT1 base: 0x4000.1000 Offset 0xFFC Type RO, reset 0x0000.00B1 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 0 RO 1 RO 1 RO 0 RO 0 RO 0 RO 1 reserved Type Reset reserved Type Reset CID3 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID3 RO 0xB1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Watchdog PrimeCell ID Register [31:24] 1052 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 15 Analog-to-Digital Converter (ADC) An analog-to-digital converter (ADC) is a peripheral that converts a continuous analog voltage to a discrete digital number. Two identical converter modules are included, which share 20 input channels. The TM4C1294NCPDT ADC module features 12-bit conversion resolution and supports 20 input channels, plus an internal temperature sensor. Each ADC module contains four programmable sequencers allowing the sampling of multiple analog input sources without controller intervention. Each sample sequencer provides flexible programming with fully configurable input source, trigger events, interrupt generation, and sequencer priority. In addition, the conversion value can optionally be diverted to a digital comparator module. Each ADC module provides eight digital comparators. Each digital comparator evaluates the ADC conversion value against its two user-defined values to determine the operational range of the signal. The trigger source for ADC0 and ADC1 may be independent or the two ADC modules may operate from the same trigger source and operate on the same or different inputs. A phase shifter can delay the start of sampling by a specified phase angle. When using both ADC modules, it is possible to configure the converters to start the conversions coincidentally or within a relative phase from each other, see “Sample Phase Control” on page 1060. The TM4C1294NCPDT microcontroller provides two ADC modules with each having the following features: ■ 20 shared analog input channels ■ 12-bit precision ADC ■ Single-ended and differential-input configurations ■ On-chip internal temperature sensor ■ Maximum sample rate of two million samples/second ■ Optional, programmable phase delay ■ Sample and hold window programmability ■ Four programmable sample conversion sequencers from one to eight entries long, with corresponding conversion result FIFOs ■ Flexible trigger control – Controller (software) – Timers – Analog Comparators – PWM – GPIO ■ Hardware averaging of up to 64 samples ■ Eight digital comparators June 18, 2014 1053 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) ■ Converter uses signals VREFA+ and GNDA as the voltage reference ■ Power and ground for the analog circuitry is separate from the digital power and ground ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Dedicated channel for each sample sequencer – ADC module uses burst requests for DMA ■ Global Alternate Clock (ALTCLK) resource or System Clock (SYSCLK) can be used to generate ADC clock 15.1 Block Diagram The TM4C1294NCPDT microcontroller contains two identical Analog-to-Digital Converter modules. These two modules, ADC0 and ADC1, share the same 20 analog input channels. Each ADC module operates independently and can therefore execute different sample sequences, sample any of the analog input channels at any time, and generate different interrupts and triggers. Figure 15-1 on page 1054 shows how the two modules are connected to analog inputs and the system bus. Figure 15-1. Implementation of Two ADC Blocks Triggers ADC 0 Input Channels Interrupts/ Triggers ADC 1 Interrupts/ Triggers Figure 15-2 on page 1055 provides details on the internal configuration of the ADC controls and data registers. 1054 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 15-2. ADC Module Block Diagram External Voltage Ref VDDA/GNDA Trigger Events Comparator GPIO Timer PWM SS3 Comparator GPIO Timer PWM Sample Sequencer 0 Control/Status SS2 ADCSSMUX0 ADCACTSS ADCSSEMUX0 ADCOSTAT ADCSSCTL0 ADCUSTAT ADCSSFSTAT0 Analog Inputs (AINx) ADCSSPRI Sample Sequencer 1 ADCSPC ADCPP Comparator GPIO Timer PWM Analog-to-Digital Converter SS1 ADCPC ADCSSMUX1 ADCTSSEL ADCSSEMUX1 Hardware Averager ADCSAC ADCSSCTL1 ADCCC ADCSSFSTAT1 Comparator GPIO Timer PWM Sample Sequencer 2 SS0 ADCSSMUX2 ADCSSEMUX2 ADCEMUX FIFO Block ADCSSCTL2 ADCPSSI ADCSSOPn ADCSSFSTAT2 SS0 Interrupt SS1 Interrupt SS2 Interrupt SS3 Interrupt Sample Sequencer 3 ADCSSMUX3 Interrupt Control Digital Comparator ADCSSFIFO0 ADCSSDCn ADCSSFIFO1 ADCDCCTLn ADCSSFIFO2 ADCDCCMPn ADCSSFIFO3 ADCDCRIC ADCSSEMUX3 ADCIM ADCSSCTL3 ADCRIS ADCSSFSTAT3 ADCISC DC Interrupts ADCDCISC PWM Trigger 15.2 Signal Description The following table lists the external signals of the ADC module and describes the function of each. The AINx signals are analog functions for some GPIO signals. The column in the table below titled "Pin Mux/Pin Assignment" lists the GPIO pin placement for the ADC signals. These signals are configured by clearing the corresponding DEN bit in the GPIO Digital Enable (GPIODEN) register and setting the corresponding AMSEL bit in the GPIO Analog Mode Select (GPIOAMSEL) register. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. The VREFA+ signal (with the word "fixed" in the Pin Mux/Pin Assignment column) has a fixed pin assignment and function. Table 15-1. ADC Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description AIN0 12 PE3 I Analog Analog-to-digital converter input 0. AIN1 13 PE2 I Analog Analog-to-digital converter input 1. AIN2 14 PE1 I Analog Analog-to-digital converter input 2. AIN3 15 PE0 I Analog Analog-to-digital converter input 3. AIN4 128 PD7 I Analog Analog-to-digital converter input 4. AIN5 127 PD6 I Analog Analog-to-digital converter input 5. AIN6 126 PD5 I Analog Analog-to-digital converter input 6. AIN7 125 PD4 I Analog Analog-to-digital converter input 7. June 18, 2014 1055 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Table 15-1. ADC Signals (128TQFP) (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description AIN8 124 PE5 I Analog Analog-to-digital converter input 8. AIN9 123 PE4 I Analog Analog-to-digital converter input 9. AIN10 121 PB4 I Analog Analog-to-digital converter input 10. AIN11 120 PB5 I Analog Analog-to-digital converter input 11. AIN12 4 PD3 I Analog Analog-to-digital converter input 12. AIN13 3 PD2 I Analog Analog-to-digital converter input 13. AIN14 2 PD1 I Analog Analog-to-digital converter input 14. AIN15 1 PD0 I Analog Analog-to-digital converter input 15. AIN16 18 PK0 I Analog Analog-to-digital converter input 16. AIN17 19 PK1 I Analog Analog-to-digital converter input 17. AIN18 20 PK2 I Analog Analog-to-digital converter input 18. AIN19 21 PK3 I Analog Analog-to-digital converter input 19. VREFA+ 9 fixed - Analog A reference voltage used to specify the voltage at which the ADC converts to a maximum value. This pin is used in conjunction with GNDA. The voltage that is applied to VREFA+ is the voltage with which an AINn signal is converted to 4095. The VREFA+ voltage is limited to the range specified in Table 27-44 on page 1861. 15.3 Functional Description The TM4C1294NCPDT ADC collects sample data by using a programmable sequence-based approach instead of the traditional single or double-sampling approaches found on many ADC modules. Each sample sequence is a fully programmed series of consecutive (back-to-back) samples, allowing the ADC to collect data from multiple input sources without having to be re-configured or serviced by the processor. The programming of each sample in the sample sequence includes parameters such as the input source and mode (differential versus single-ended input), interrupt generation on sample completion, and the indicator for the last sample in the sequence. In addition, the μDMA can be used to more efficiently move data from the sample sequencers without CPU intervention. 15.3.1 Sample Sequencers The sampling control and data capture is handled by the sample sequencers. All of the sequencers are identical in implementation except for the number of samples that can be captured and the depth of the FIFO. Table 15-2 on page 1056 shows the maximum number of samples that each sequencer can capture and its corresponding FIFO depth. Each sample that is captured is stored in the FIFO. In this implementation, each FIFO entry is a 32-bit word, with the lower 12 bits containing the conversion result. Table 15-2. Samples and FIFO Depth of Sequencers Sequencer Number of Samples Depth of FIFO SS3 1 1 SS2 4 4 SS1 4 4 SS0 8 8 1056 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller For a given sample sequence, each sample is defined by bit fields in the ADC Sample Sequence Input Multiplexer Select (ADCSSMUXn), ADC Sample Sequence Extended Input Multiplexer Select (ADCSSEMUXn) and ADC Sample Sequence Control (ADCSSCTLn) registers, where "n" corresponds to the sequence number. The ADCSSMUXn and ADCSSEMUXn fields select the input pin, while the ADCSSCTLn fields contain the sample control bits corresponding to parameters such as temperature sensor selection, interrupt enable, end of sequence, and differential input mode. Sample sequencers are enabled by setting the respective ASENn bit in the ADC Active Sample Sequencer (ADCACTSS) register and should be configured before being enabled. Sampling is then initiated by setting the SSn bit in the ADC Processor Sample Sequence Initiate (ADCPSSI) register. In addition, sample sequences may be initiated on multiple ADC modules simultaneously using the GSYNC and SYNCWAIT bits in the ADCPSSI register during the configuration of each ADC module. For more information on using these bits, refer to page 1103. When configuring a sample sequence, multiple uses of the same input pin within the same sequence are allowed. In the ADCSSCTLn register, the IEn bits can be set for any combination of samples, allowing interrupts to be generated after every sample in the sequence if necessary. Also, the END bit can be set at any point within a sample sequence. For example, if Sequencer 0 is used, the END bit can be set in the nibble associated with the fifth sample, allowing Sequencer 0 to complete execution of the sample sequence after the fifth sample. After a sample sequence completes execution, the result data can be retrieved from the ADC Sample Sequence Result FIFO (ADCSSFIFOn) registers. The FIFOs are simple circular buffers that read a single address to "pop" result data. For software debug purposes, the positions of the FIFO head and tail pointers are visible in the ADC Sample Sequence FIFO Status (ADCSSFSTATn) registers along with FULL and EMPTY status flags. If a write is attempted when the FIFO is full, the write does not occur and an overflow condition is indicated. Overflow and underflow conditions are monitored using the ADCOSTAT and ADCUSTAT registers. 15.3.2 Module Control Outside of the sample sequencers, the remainder of the control logic is responsible for tasks such as: ■ Interrupt generation ■ DMA operation ■ Sequence prioritization ■ Trigger configuration ■ Comparator configuration ■ External voltage reference ■ Sample phase control ■ Module clocking 15.3.2.1 Interrupts The register configurations of the sample sequencers and digital comparators dictate which events generate raw interrupts, but do not have control over whether the interrupt is actually sent to the interrupt controller. The ADC module's interrupt signals are controlled by the state of the MASK bits in the ADC Interrupt Mask (ADCIM) register. Interrupt status can be viewed at two locations: the ADC Raw Interrupt Status (ADCRIS) register, which shows the raw status of the various interrupt June 18, 2014 1057 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) signals; and the ADC Interrupt Status and Clear (ADCISC) register, which shows active interrupts that are enabled by the ADCIM register. Sequencer interrupts are cleared by writing a 1 to the corresponding IN bit in ADCISC. Digital comparator interrupts are cleared by writing a 1 to the ADC Digital Comparator Interrupt Status and Clear (ADCDCISC) register. 15.3.2.2 DMA Operation DMA may be used to increase efficiency by allowing each sample sequencer to operate independently and transfer data without processor intervention or reconfiguration. The ADC asserts single and burst µDMA request signals (dma_sreq and dma_req) to the µDMA controller based on the FIFO level. The dma_req signal is generated when the FIFO in question is half-full (that is, at 4 samples for SS0, 2 samples for SS1 and SS2, and at 1 sample for SS3). If, for example, the ADCSSCTL0 register has six samples to transfer, a burst of four values occurs followed by two single transfers (dma_sreq). The dma_done signals (one per sample sequencer) are sent to the ADC to allow for a triggering of DMAINRn interrupt bits in the ADCRIS register. The µDMA is enabled for a specific sample sequencer by setting the appropriate ADENn bit in the ADCACTSS register at offset 0x000. To use the µDMA with the ADC module, the application must enable the ADC channel through DMA Channel Map Select n (DMACHMAPn) register in the µDMA. Refer to the “Micro Direct Memory Access (μDMA)” on page 678 for more details about programming the μDMA controller. 15.3.2.3 Prioritization When sampling events (triggers) happen concurrently, they are prioritized for processing by the values in the ADC Sample Sequencer Priority (ADCSSPRI) register. Valid priority values are in the range of 0-3, with 0 being the highest priority and 3 being the lowest. Multiple active sample sequencer units with the same priority do not provide consistent results, so software must ensure that all active sample sequencer units have a unique priority value. 15.3.2.4 Sampling Events Sample triggering for each sample sequencer is defined in the ADC Event Multiplexer Select (ADCEMUX) register. Trigger sources include processor (default), analog comparators, an external signal on a GPIO specified by the GPIO ADC Control (GPIOADCCTL) register, a GP Timer, a PWM generator, and continuous sampling. The processor triggers sampling by setting the SSx bits in the ADC Processor Sample Sequence Initiate (ADCPSSI) register. Care must be taken when using the continuous sampling trigger. If a sequencer's priority is too high, it is possible to starve other lower priority sequencers. Generally, a sample sequencer using continuous sampling should be set to the lowest priority. Continuous sampling can be used with a digital comparator to cause an interrupt when a particular voltage is seen on an input. 15.3.2.5 Sample and Hold Window Control The ADC module provides the capability of programming the sample and hold window of each step in a sequence through the ADC Sample Sequence n Sample and Hold Time (ADCSSTSHn) register. Each TSHn field can be written with a different sample and hold width, which is represented in ADC clocks. The table below gives the allowed encodings: Table 15-3. Sample and Hold Width in ADC Clocks TSHn Encoding NSH 0x0 4 1058 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 15-3. Sample and Hold Width in ADC Clocks (continued) TSHn Encoding NSH 0x1 reserved 0x2 8 0x3 reserved 0x4 16 0x5 reserved 0x6 32 0x7 reserved 0x8 64 0x9 reserved 0xA 128 0xB reserved 0xC 256 0xD-0xF reserved The ADC conversion frequency is a function of the Sample and Hold number, given by the following equation: FCONV = 1/((NSH + 12)*TADC) where: ■ NSH is the sample and hold width in ADC clocks ■ TADC is the ADC conversion clock period, which is the inverse of the ADC clock frequency FADC Now, the maximum allowable external source resistance (RS) also changes with the value of NSH, as the total settling time of the input circuitry must be fast enough to settle to within the ADC resolution in a single sampling interval. The input circuitry includes the external source resistance as well as the input resistance and capacitance of the ADC (RADC and CADC). The values for RS and FCONV for varying NSH values, with FADC=16MHz and FADC=32MHz are given in tables 18-4-a and 18-4-b. The system designer must take into consideration both of these factors for optimal ADC operation. Table 15-4. RS and FCONV Values with Varying NSH Values and FADC = 16 MHz NSH (Cycles) 4 8 16 32 64 128 256 FCONV (Ksps) 1000 800 571 364 211 114 60 RS Max (Ω) 500 3500 9500 21500 45500 93500 189500 Table 15-5. RS and FCONV Values with Varying NSH Values and FADC = 32 MHz NSH (Cycles) 4 8 16 32 64 128 256 FCONV (Ksps) 2000 1600 1143 727 421 229 119 RS Max (Ω) 250 500 3500 9500 21500 45500 93500 June 18, 2014 1059 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) 15.3.2.6 Sample Phase Control The trigger source for ADC0 and ADC1 may be independent or the two ADC modules may operate from the same trigger source and operate on the same or different inputs. If the converters are running at the same sample rate, they may be configured to start the conversions coincidentally or one ADC may be programmed to lag up to 15 clock cycles relative to the other ADC. The sample time can be delayed from the standard sampling time by programming the PHASE field in the ADC Sample Phase Control (ADCSPC) register. Figure 15-3 on page 1060 shows an example of various phase relationships. Figure 15-3. ADC Sample Phases 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ADC Sample Clock PHASE 0x0 (no lag) PHASE 0x1 (1 ADC clock lag) . . . . . . . . . . . . PHASE 0xE (14 ADC clock lag) PHASE 0xF (15 ADC clock lag) This feature can be used to double the sampling rate of an input. Both ADC Module 0 and ADC Module 1 can be programmed to sample the same input. ADC module 0 can sample at the standard position (the PHASE field in the ADCSPC register is 0x0). ADC Module 1 can be configured to sample with a phase lag (PHASE is nonzero). For a sample rate of two million samples/second at 16MHz, the TSHn field of all of the sequencer samples of both ADCs must be programmed to 0x0 and the PHASE field of one of the ADC modules must be set to 0x8. The two modules can be be synchronized using the GSYNC and SYNCWAIT bits in the ADC Processor Sample Sequence Initiate (ADCPSSI) register. Software can then combine the results from the two modules to create a sample rate of two million samples/second at 16MHz as shown in Figure 15-4 on page 1060. Figure 15-4. Doubling the ADC Sample Rate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ADC Sample Clock GSYNC ADC 0 PHASE 0x0 (0.0°) ADC 1 PHASE 0x8 (180.0°) Using the ADCSPC register, ADC0 and ADC1 may provide a number of interesting applications: ■ Coincident continuous sampling of different signals. The sample sequence steps run coincidently in both converters. In this situation, the TSHn of matching sample steps of both ADC module sequencers must be the same and the PHASE field must be 0x0 in both ADC module ADCSPC registers. The TSHn field is found in the ADC Sample Sequence n Sample and Hold Time (ADCSSTSHn) register. – ADC Module 0, ADCSPC = 0x0, sampling AIN0 1060 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller – ADC Module 1, ADCSPC = 0x0, sampling AIN1 Note: If two ADCs are configured to sample the same signal, a skew (phase lag) must be added to one of the ADC modules to prevent coincident sampling. Phase lag can be added by programming the PHASE field in the ADCSPC register. ■ Skewed sampling of the same signal. The skew is determined by both the TSHn field in the ADCSSTSHn registers and the PHASE field in the ADCSPC register. For the fastest skewed sample rate, all TSHn fields must be programmed to 0x0. If TSHn=0x0 for all sequencers and the PHASE field of one ADC is 0x8, the configuration doubles the conversion bandwidth of a single input when software combines the results as shown in Figure 15-5 on page 1061. – ADC Module 0, ADCSPC = 0x0, sampling AIN0 – ADC Module 1, ADCSPC = 0x8, sampling AIN0 Note that it is not required that the TSHn fields be the same in a skewed sample. If an application has varying analog input resistance, then TSHn and PHASE may vary according to operational requirements. Figure 15-5. Skewed Sampling ADC0 ADC1 15.3.2.7 S1 S2 S1 S3 S2 S4 S3 S5 S4 S6 S5 S7 S6 S8 S7 S8 Module Clocking The ADC digital block is clocked by the system clock and the ADC analog block is clocked from a separate conversion clock (ADC Clock). The ADC clock frequency can be up to 32 MHz to generate a conversion rate of 2 Msps. A 16 MHz ADC clock provides a 1 Msps sampling rate. There are three sources of the ADC clock: ■ Divided PLL VCO. The PLL VCO frequency can be configured to generate up to a 32-MHz clock for a conversion rate of 2 Msps. The CS field in the ADCCC register must be programmed to 0x0 to select the PLL VCO and the CLKDIV field is used to set the appropriate clock divisor for the desired frequency. June 18, 2014 1061 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) ■ 16 MHz PIOSC. Using the PIOSC provides a conversion rate near 1 Msps. To use the PIOSC to clock the ADC, first power up the PLL and then enable the PIOSC in the CS bit field in the ADCCC register, then disable the PLL. ■ MOSC. The MOSC clock source must be 16 MHz for a 1 Msps conversion rate and 32 MHz for a 2 Msps conversion rate. The system clock must be at the same frequency or higher than the ADC clock. All ADC modules share the same clock source to facilitate the synchronization of data samples between conversion units, the selection and programming of which is provided by ADC0's ADCCC register. The ADC modules do not run at different conversion rates. 15.3.2.8 Busy Status The BUSY bit of the ADCACTSS register is used to indicate when the ADC is busy with a current conversion. When there are no triggers pending which may start a new conversion in the immediate cycle or next few cycles, the BUSY bit reads as 0. Software must read the status of the BUSY bit as clear before disabling the ADC clock by writing to the Analog-to-Digital Converter Run Mode Clock Gating Control (RCGCADC) register. 15.3.3 Hardware Sample Averaging Circuit Higher precision results can be generated using the hardware averaging circuit, however, the improved results are at the cost of throughput. Up to 64 samples can be accumulated and averaged to form a single data entry in the sequencer FIFO. Throughput is decreased proportionally to the number of samples in the averaging calculation. For example, if the averaging circuit is configured to average 16 samples, the throughput is decreased by a factor of 16. By default the averaging circuit is off, and all data from the converter passes through to the sequencer FIFO. The averaging hardware is controlled by the ADC Sample Averaging Control (ADCSAC) register (see page 1105). A single averaging circuit has been implemented, thus all input channels receive the same amount of averaging whether they are single-ended or differential. Figure 15-6 shows an example in which the ADCSAC register is set to 0x2 for 4x hardware oversampling and the IE1 bit is set for the sample sequence, resulting in an interrupt after the second averaged value is stored in the FIFO. 1062 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 15-6. Sample Averaging Example A+B+C+D 4 A+B+C+D 4 INT 15.3.4 Analog-to-Digital Converter The Analog-to-Digital Converter (ADC) module uses a Successive Approximation Register (SAR) architecture to deliver a 12-bit, low-power, high-precision conversion value. The successive approximation uses a switched capacitor array to perform the dual functions of sampling and holding the signal as well as providing the 12-bit DAC operation. Figure 15-7 shows the ADC input equivalency diagram; for parameter values, see “Analog-to-Digital Converter (ADC)” on page 1861. June 18, 2014 1063 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Figure 15-7. ADC Input Equivalency Tiva™ Microcontroller VDD Zs Rs VS Input PAD Equivalent Circuit ZADC RADC Pin Cs VADCIN ESD Clamp 12-bit SAR ADC Converter 12-bit Word IL Pin Input PAD Equivalent Circuit Pin Input PAD Equivalent Circuit RADC RADC CADC The ADC operates from both the 3.3-V analog and 1.2-V digital power supplies. The ADC clock can be configured to reduce power consumption when ADC conversions are not required (see “System Control” on page 239). The analog inputs are connected to the ADC through specially balanced input paths to minimize the distortion and cross-talk on the inputs. Detailed information on the ADC power supplies and analog inputs can be found in “Analog-to-Digital Converter (ADC)” on page 1861. 15.3.4.1 Voltage Reference The ADC uses internal signals VREFP and VREFN as references to produce a conversion value from the selected analog input. VREFP can be connected to either VREFA+ or VDDA and VREFN is connected to GNDA as configured by the VREF bit in the ADC Control (ADCCTL) register, as shown in Figure 15-8. Figure 15-8. ADC Voltage Reference VDDA VREFP VREFA+ Voltage reference selected using the VREF field in the ADCCTL register GNDA VREFN GNDA ADC 1064 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The range of this conversion value is from 0x000 to 0xFFF. In single-ended-input mode, the 0x000 value corresponds to the voltage level on VREFN; the 0xFFF value corresponds to the voltage level on VREFP. This configuration results in a resolution that can be calculated using the following equation: mV per ADC code = (VREFP - VREFN) / 4096 While the analog input pads can handle voltages beyond this range, the analog input voltages must remain within the limits prescribed by Table 27-44 on page 1861 to produce accurate results. The VREFA+ specification defines the useful range for the external voltage reference on VREFA+ and GNDA, see Table 27-44 on page 1861. Care must be taken to supply a reference voltage of acceptable quality.Figure 15-9 on page 1065 shows the ADC conversion function of the analog inputs. Figure 15-9. ADC Conversion Result 0xFFF 0xC00 0x800 R EF P VIN -V VR ) EF N N EF P ¾ (V R EF EF ½ ¼ (V (V R R EF P P -V -V R R VR EF N ) ) EF N 0x400 - Input Saturation 15.3.5 Differential Sampling In addition to traditional single-ended sampling, the ADC module supports differential sampling of two analog input channels. To enable differential sampling, software must set the Dn bit in the ADCSSCTL0n register in a step's configuration nibble. When a sequence step is configured for differential sampling, the input pair to sample must be configured in the ADCSSMUXn register. Differential pair 0 samples analog inputs 0 and 1; differential June 18, 2014 1065 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) pair 1 samples analog inputs 2 and 3; and so on (see Table 15-6 on page 1066). The ADC does not support other differential pairings such as analog input 0 with analog input 3. Table 15-6. Differential Sampling Pairs Differential Pair Analog Inputs 0 0 and 1 1 2 and 3 2 4 and 5 3 6 and 7 4 8 and 9 5 10 and 11 6 12 and 13 7 14 and 15 8 16 and 17 9 18 and 19 The voltage sampled in differential mode is the difference between the odd and even channels: ■ Input Positive Voltage: VIN+ = VIN_EVEN (even channel) ■ Input Negative Voltage: VIN- = VIN_ODD (odd channel) The input differential voltage is defined as: VIND = VIN+ - VIN-, therefore: ■ If VIND = 0, then the conversion result = 0x800 ■ If VIND > 0, then the conversion result > 0x800 (range is 0x800–0xFFF) ■ If VIND < 0, then the conversion result < 0x800 (range is 0–0x800) When using differential sampling, the following definitions are relevant: ■ Input Common Mode Voltage: VINCM = (VIN+ + VIN-) / 2 ■ Reference Positive Voltage: VREFP ■ Reference Negative Voltage: VREFN ■ Reference Differential Voltage: VREFD = VREFP - VREFN ■ Reference Common Mode Voltage: VREFCM = (VREFP + VREFN) / 2 The following conditions provide optimal results in differential mode: ■ Both VIN_EVEN and VIN_ODD must be in the range of (VREFP to VREFN) for a valid conversion result ■ The maximum possible differential input swing, or the maximum differential range, is: -VREFDto +VREFD, so the maximum peak-to-peak input differential signal is (+VREFD - -VREFD) = 2 * VREFD= 2 * (VREFP - VREFN) 1066 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ In order to take advantage of the maximum possible differential input swing, VINCM should be very close to VREFCM, see Table 27-44 on page 1861. If VINCM is not equal to VREFCM, the differential input signal may clip at either maximum or minimum voltage, because either single ended input can never be larger than VREFP or smaller than VREFN, and it is not possible to achieve full swing. Thus any difference in common mode between the input voltage and the reference voltage limits the differential dynamic range of the ADC. Because the maximum peak-to-peak differential signal voltage is 2 * (VREFP - VREFN), the ADC codes are interpreted as: mV per ADC code = (2 *(VREFP - VREFN)) / 4096 Figure 15-10 shows how the differential voltage, ∆V, is represented in ADC codes. Figure 15-10. Differential Voltage Representation 0xFFF 0x800 -(VREFP - VREFN) 0 VREFP - VREFN V - Input Saturation 15.3.6 Internal Temperature Sensor The temperature sensor serves two primary purposes: 1) to notify the system that internal temperature is too high or low for reliable operation and 2) to provide temperature measurements for calibration of the Hibernate module RTC trim value. The temperature sensor does not have a separate enable, because it also contains the bandgap reference and must always be enabled. The reference is supplied to other analog modules; not just the ADC. In addition, the temperature sensor has a second power-down input in the 3.3 V domain which provides control by the Hibernation module. The internal temperature sensor converts a temperature measurement into a voltage. This voltage value, VTSENS, is given by the following equation (where TEMP is the temperature in °C): VTSENS = 2.7 - ((TEMP + 55) / 75) This relation is shown in Figure 15-11 on page 1068. June 18, 2014 1067 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Figure 15-11. Internal Temperature Sensor Characteristic VTSENS VTSENS = 2.7 V – (TEMP+55) 75 2.5 V 1.633 V 0.833 V -40° C 25° C 85° C Temp The temperature sensor reading can be sampled in a sample sequence by setting the TSn bit in the ADCSSCTLn register. The sample and hold width should be configured for at least 16 ADC clocks using the ADCSSTSHn register. The temperature reading from the temperature sensor can also be given as a function of the ADC value. The following formula calculates temperature (TEMP in ℃) based on the ADC reading (ADCCODE, given as an unsigned decimal number from 0 to 4095) and the maximum ADC voltage range (VREFP - VREFN): TEMP = 147.5 - ((75 * (VREFP - VREFN) × ADCCODE) / 4096) 15.3.7 Digital Comparator Unit An ADC is commonly used to sample an external signal and to monitor its value to ensure that it remains in a given range. To automate this monitoring procedure and reduce the amount of processor overhead that is required, each module provides eight digital comparators. Conversions from the ADC that are sent to the digital comparators are compared against the user programmable limits in the ADC Digital Comparator Range (ADCDCCMPn) registers. The ADC can be configured to generate an interrupt depending on whether the ADC is operating within the low, mid or high-band region configured in the ADCDCCMPn bit fields. The digital comparators four operational modes (Once, Always, Hysteresis Once, Hysteresis Always) can be additionally applied to the interrupt configuration. 15.3.7.1 Output Functions ADC conversions can either be stored in the ADC Sample Sequence FIFOs or compared using the digital comparator resources as defined by the SnDCOP bits in the ADC Sample Sequence n Operation (ADCSSOPn) register. These selected ADC conversions are used by their respective digital comparator to monitor the external signal. Each comparator has two possible output functions: processor interrupts and triggers. Each function has its own state machine to track the monitored signal. Even though the interrupt and trigger functions can be enabled individually or both at the same time, the same conversion 1068 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller data is used by each function to determine if the right conditions have been met to assert the associated output. Interrupts The digital comparator interrupt function is enabled by setting the CIE bit in the ADC Digital Comparator Control (ADCDCCTLn) register. This bit enables the interrupt function state machine to start monitoring the incoming ADC conversions. When the appropriate set of conditions is met, and the DCONSSx bit is set in the ADCIM register, an interrupt is sent to the interrupt controller. Note: For a 1 to 2 Msps rate, as the system clock frequency approaches the ADC clock frequency, it is recommended that the application use the µDMA to store conversion data from the FIFO to memory before processing rather than an interrupt-driven single data read. Using the µDMA to store multiple samples before interrupting the processor amortizes interrupt overhead across multiple transfers and prevents loss of sample data. Note: Only a single DCONSSn bit should be set at any given time. Setting more than one of these bits results in the INRDC bit from the ADCRIS register being masked, and no interrupt is generated on any of the sample sequencer interrupt lines. It is recommended that when interrupts are used, they are enabled on alternating samples or at the end of the sample sequence. Triggers The digital comparator trigger function is enabled by setting the CTE bit in the ADCDCCTLn register. This bit enables the trigger function state machine to start monitoring the incoming ADC conversions. When the appropriate set of conditions is met, the corresponding digital comparator trigger to the PWM module is asserted. 15.3.7.2 Operational Modes Four operational modes are provided to support a broad range of applications and multiple possible signaling requirements: Always, Once, Hysteresis Always, and Hysteresis Once. The operational mode is selected using the CIM or CTM field in the ADCDCCTLn register. Always Mode In the Always operational mode, the associated interrupt or trigger is asserted whenever the ADC conversion value meets its comparison criteria. The result is a string of assertions on the interrupt or trigger while the conversions are within the appropriate range. Once Mode In the Once operational mode, the associated interrupt or trigger is asserted whenever the ADC conversion value meets its comparison criteria, and the previous ADC conversion value did not. The result is a single assertion of the interrupt or trigger when the conversions are within the appropriate range. Hysteresis-Always Mode The Hysteresis-Always operational mode can only be used in conjunction with the low-band or high-band regions because the mid-band region must be crossed and the opposite region entered to clear the hysteresis condition. In the Hysteresis-Always mode, the associated interrupt or trigger is asserted in the following cases: 1) the ADC conversion value meets its comparison criteria or 2) a previous ADC conversion value has met the comparison criteria, and the hysteresis condition has not been cleared by entering the opposite region. The result is a string of assertions on the interrupt or trigger that continue until the opposite region is entered. June 18, 2014 1069 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Hysteresis-Once Mode The Hysteresis-Once operational mode can only be used in conjunction with the low-band or high-band regions because the mid-band region must be crossed and the opposite region entered to clear the hysteresis condition. In the Hysteresis-Once mode, the associated interrupt or trigger is asserted only when the ADC conversion value meets its comparison criteria, the hysteresis condition is clear, and the previous ADC conversion did not meet the comparison criteria. The result is a single assertion on the interrupt or trigger. 15.3.7.3 Function Ranges The two comparison values, COMP0 and COMP1, in the ADC Digital Comparator Range (ADCDCCMPn) register effectively break the conversion area into three distinct regions. These regions are referred to as the low-band (less than COMP0), mid-band (greater than COMP0 but less than or equal to COMP1), and high-band (greater than or equal to COMP1) regions. COMP0 and COMP1 may be programmed to the same value, effectively creating two regions, but COMP1 must always be greater than or equal to the value of COMP0. A COMP1 value that is less than COMP0 generates unpredictable results. Low-Band Operation To operate in the low-band region, the CIC field or the CTC field in the ADCDCCTLn register must be programmed to 0x0. This setting causes interrupts or triggers to be generated in the low-band region as defined by the programmed operational mode. An example of the state of the interrupt/trigger signal in the low-band region for each of the operational modes is shown in Figure 15-12 on page 1070. Note that a "0" in a column following the operational mode name (Always, Once, Hysteresis Always, and Hysteresis Once) indicates that the interrupt or trigger signal is deasserted and a "1" indicates that the signal is asserted. Figure 15-12. Low-Band Operation (CIC=0x0 and/or CTC=0x0) COMP1 COMP0 Always – 0 0 0 0 1 1 1 0 0 1 1 0 0 0 0 1 Once – 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 1 Hysteresis Always – 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 1 Hysteresis Once – 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 1070 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Mid-Band Operation To operate in the mid-band region, the CIC field or the CTC field in the ADCDCCTLn register must be programmed to 0x1. This setting causes interrupts or triggers to be generated in the mid-band region according the operation mode. Only the Always and Once operational modes are available in the mid-band region. An example of the state of the interrupt/trigger signal in the mid-band region for each of the allowed operational modes is shown in Figure 15-13 on page 1071. Note that a "0" in a column following the operational mode name (Always or Once) indicates that the interrupt or trigger signal is deasserted and a "1" indicates that the signal is asserted. Figure 15-13. Mid-Band Operation (CIC=0x1 and/or CTC=0x1) COMP1 COMP0 Always – 0 0 1 1 0 0 0 1 1 1 0 0 1 1 0 0 Once – 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 Hysteresis Always – - - - - - - - - - - - - - - - - Hysteresis Once – - - - - - - - - - - - - - - - - High-Band Operation To operate in the high-band region, the CIC field or the CTC field in the ADCDCCTLn register must be programmed to 0x3. This setting causes interrupts or triggers to be generated in the high-band region according the operation mode. An example of the state of the interrupt/trigger signal in the high-band region for each of the allowed operational modes is shown in Figure 15-14 on page 1072. Note that a "0" in a column following the operational mode name (Always, Once, Hysteresis Always, and Hysteresis Once) indicates that the interrupt or trigger signal is deasserted and a "1" indicates that the signal is asserted. June 18, 2014 1071 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Figure 15-14. High-Band Operation (CIC=0x3 and/or CTC=0x3) COMP1 COMP0 Always – 0 0 0 0 1 1 1 0 0 1 1 0 0 0 1 1 Once – 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 Hysteresis Always – 0 0 0 0 1 1 1 1 1 1 1 1 0 0 1 1 Hysteresis Once – 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 15.4 Initialization and Configuration 15.4.1 Module Initialization Initialization of the ADC module is a simple process with very few steps: enabling the clock to the ADC, disabling the analog isolation circuit associated with all inputs that are to be used, and reconfiguring the sample sequencer priorities (if needed). The initialization sequence for the ADC is as follows: 1. Enable the ADC clock using the RCGCADC register (see page 396). 2. Enable the clock to the appropriate GPIO modules via the RCGCGPIO register (see page 382). To find out which GPIO ports to enable, refer to “Signal Description” on page 1055. 3. Set the GPIO AFSEL bits for the ADC input pins (see page 770). To determine which GPIOs to configure, see Table 26-4 on page 1797. 4. Configure the AINx signals to be analog inputs by clearing the corresponding DEN bit in the GPIO Digital Enable (GPIODEN) register (see page 781). 5. Disable the analog isolation circuit for all ADC input pins that are to be used by writing a 1 to the appropriate bits of the GPIOAMSEL register (see page 786) in the associated GPIO block. 6. If required by the application, reconfigure the sample sequencer priorities in the ADCSSPRI register. The default configuration has Sample Sequencer 0 with the highest priority and Sample Sequencer 3 as the lowest priority. 1072 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 15.4.2 Sample Sequencer Configuration Configuration of the sample sequencers is slightly more complex than the module initialization because each sample sequencer is completely programmable. The configuration for each sample sequencer should be as follows: 1. Ensure that the sample sequencer is disabled by clearing the corresponding ASENn bit in the ADCACTSS register. Programming of the sample sequencers is allowed without having them enabled. Disabling the sequencer during programming prevents erroneous execution if a trigger event were to occur during the configuration process. 2. Configure the trigger event for the sample sequencer in the ADCEMUX register. 3. When using a PWM generator as the trigger source, use the ADC Trigger Source Select (ADCTSSEL) register to specify in which PWM module the generator is located. The default register reset selects PWM module 0 for all generators. 4. For each sample in the sample sequence, configure the corresponding input source in the ADCSSMUXn and ADCSSEMUXn registers. 5. For each sample in the sample sequence, configure the sample control bits in the corresponding nibble in the ADCSSCTLn register. When programming the last nibble, ensure that the END bit is set. Failure to set the END bit causes unpredictable behavior. 6. If interrupts are to be used, set the corresponding MASK bit in the ADCIM register. 7. Enable the sample sequencer logic by setting the corresponding ASENn bit in the ADCACTSS register. 15.5 Register Map Table 15-7 on page 1073 lists the ADC registers. The offset listed is a hexadecimal increment to the register's address, relative to that ADC module's base address of: ■ ADC0: 0x4003.8000 ■ ADC1: 0x4003.9000 Note that the ADC module clock must be enabled before the registers can be programmed (see page 396). There must be a delay of 3 system clocks after the ADC module clock is enabled before any ADC module registers are accessed. Table 15-7. ADC Register Map Description See page 0x0000.0000 ADC Active Sample Sequencer 1077 RO 0x0000.0000 ADC Raw Interrupt Status 1079 ADCIM RW 0x0000.0000 ADC Interrupt Mask 1082 0x00C ADCISC RW1C 0x0000.0000 ADC Interrupt Status and Clear 1085 0x010 ADCOSTAT RW1C 0x0000.0000 ADC Overflow Status 1089 0x014 ADCEMUX RW 0x0000.0000 ADC Event Multiplexer Select 1091 Offset Name Type Reset 0x000 ADCACTSS RW 0x004 ADCRIS 0x008 June 18, 2014 1073 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Table 15-7. ADC Register Map (continued) Description See page 0x0000.0000 ADC Underflow Status 1096 RW 0x0000.0000 ADC Trigger Source Select 1097 ADCSSPRI RW 0x0000.3210 ADC Sample Sequencer Priority 1099 0x024 ADCSPC RW 0x0000.0000 ADC Sample Phase Control 1101 0x028 ADCPSSI RW - ADC Processor Sample Sequence Initiate 1103 0x030 ADCSAC RW 0x0000.0000 ADC Sample Averaging Control 1105 0x034 ADCDCISC RW1C 0x0000.0000 ADC Digital Comparator Interrupt Status and Clear 1106 0x038 ADCCTL RW 0x0000.0000 ADC Control 1108 0x040 ADCSSMUX0 RW 0x0000.0000 ADC Sample Sequence Input Multiplexer Select 0 1109 0x044 ADCSSCTL0 RW 0x0000.0000 ADC Sample Sequence Control 0 1111 0x048 ADCSSFIFO0 RO - ADC Sample Sequence Result FIFO 0 1118 0x04C ADCSSFSTAT0 RO 0x0000.0100 ADC Sample Sequence FIFO 0 Status 1119 0x050 ADCSSOP0 RW 0x0000.0000 ADC Sample Sequence 0 Operation 1121 0x054 ADCSSDC0 RW 0x0000.0000 ADC Sample Sequence 0 Digital Comparator Select 1123 0x058 ADCSSEMUX0 RW 0x0000.0000 ADC Sample Sequence Extended Input Multiplexer Select 0 1125 0x05C ADCSSTSH0 RW 0x0000.0000 ADC Sample Sequence 0 Sample and Hold Time 1127 0x060 ADCSSMUX1 RW 0x0000.0000 ADC Sample Sequence Input Multiplexer Select 1 1129 0x064 ADCSSCTL1 RW 0x0000.0000 ADC Sample Sequence Control 1 1130 0x068 ADCSSFIFO1 RO - ADC Sample Sequence Result FIFO 1 1118 0x06C ADCSSFSTAT1 RO 0x0000.0100 ADC Sample Sequence FIFO 1 Status 1119 0x070 ADCSSOP1 RW 0x0000.0000 ADC Sample Sequence 1 Operation 1134 0x074 ADCSSDC1 RW 0x0000.0000 ADC Sample Sequence 1 Digital Comparator Select 1135 0x078 ADCSSEMUX1 RW 0x0000.0000 ADC Sample Sequence Extended Input Multiplexer Select 1 1137 0x07C ADCSSTSH1 RW 0x0000.0000 ADC Sample Sequence 1 Sample and Hold Time 1139 0x080 ADCSSMUX2 RW 0x0000.0000 ADC Sample Sequence Input Multiplexer Select 2 1129 0x084 ADCSSCTL2 RW 0x0000.0000 ADC Sample Sequence Control 2 1130 0x088 ADCSSFIFO2 RO - ADC Sample Sequence Result FIFO 2 1118 0x08C ADCSSFSTAT2 RO 0x0000.0100 ADC Sample Sequence FIFO 2 Status 1119 0x090 ADCSSOP2 RW 0x0000.0000 ADC Sample Sequence 2 Operation 1134 0x094 ADCSSDC2 RW 0x0000.0000 ADC Sample Sequence 2 Digital Comparator Select 1135 Offset Name Type Reset 0x018 ADCUSTAT RW1C 0x01C ADCTSSEL 0x020 1074 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 15-7. ADC Register Map (continued) Description See page 0x0000.0000 ADC Sample Sequence Extended Input Multiplexer Select 2 1137 RW 0x0000.0000 ADC Sample Sequence 2 Sample and Hold Time 1139 ADCSSMUX3 RW 0x0000.0000 ADC Sample Sequence Input Multiplexer Select 3 1141 0x0A4 ADCSSCTL3 RW 0x0000.0000 ADC Sample Sequence Control 3 1142 0x0A8 ADCSSFIFO3 RO - ADC Sample Sequence Result FIFO 3 1118 0x0AC ADCSSFSTAT3 RO 0x0000.0100 ADC Sample Sequence FIFO 3 Status 1119 0x0B0 ADCSSOP3 RW 0x0000.0000 ADC Sample Sequence 3 Operation 1144 0x0B4 ADCSSDC3 RW 0x0000.0000 ADC Sample Sequence 3 Digital Comparator Select 1145 0x0B8 ADCSSEMUX3 RW 0x0000.0000 ADC Sample Sequence Extended Input Multiplexer Select 3 1146 0x0BC ADCSSTSH3 RW 0x0000.0000 ADC Sample Sequence 3 Sample and Hold Time 1147 0xD00 ADCDCRIC WO 0x0000.0000 ADC Digital Comparator Reset Initial Conditions 1148 0xE00 ADCDCCTL0 RW 0x0000.0000 ADC Digital Comparator Control 0 1153 0xE04 ADCDCCTL1 RW 0x0000.0000 ADC Digital Comparator Control 1 1153 0xE08 ADCDCCTL2 RW 0x0000.0000 ADC Digital Comparator Control 2 1153 0xE0C ADCDCCTL3 RW 0x0000.0000 ADC Digital Comparator Control 3 1153 0xE10 ADCDCCTL4 RW 0x0000.0000 ADC Digital Comparator Control 4 1153 0xE14 ADCDCCTL5 RW 0x0000.0000 ADC Digital Comparator Control 5 1153 0xE18 ADCDCCTL6 RW 0x0000.0000 ADC Digital Comparator Control 6 1153 0xE1C ADCDCCTL7 RW 0x0000.0000 ADC Digital Comparator Control 7 1153 0xE40 ADCDCCMP0 RW 0x0000.0000 ADC Digital Comparator Range 0 1156 0xE44 ADCDCCMP1 RW 0x0000.0000 ADC Digital Comparator Range 1 1156 0xE48 ADCDCCMP2 RW 0x0000.0000 ADC Digital Comparator Range 2 1156 0xE4C ADCDCCMP3 RW 0x0000.0000 ADC Digital Comparator Range 3 1156 0xE50 ADCDCCMP4 RW 0x0000.0000 ADC Digital Comparator Range 4 1156 0xE54 ADCDCCMP5 RW 0x0000.0000 ADC Digital Comparator Range 5 1156 0xE58 ADCDCCMP6 RW 0x0000.0000 ADC Digital Comparator Range 6 1156 0xE5C ADCDCCMP7 RW 0x0000.0000 ADC Digital Comparator Range 7 1156 0xFC0 ADCPP RO 0x01B0.2147 ADC Peripheral Properties 1157 0xFC4 ADCPC RW 0x0000.0007 ADC Peripheral Configuration 1159 0xFC8 ADCCC RW 0x0000.0001 ADC Clock Configuration 1160 Offset Name Type Reset 0x098 ADCSSEMUX2 RW 0x09C ADCSSTSH2 0x0A0 June 18, 2014 1075 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) 15.6 Register Descriptions The remainder of this section lists and describes the ADC registers, in numerical order by address offset. 1076 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: ADC Active Sample Sequencer (ADCACTSS), offset 0x000 This register controls the activation of the sample sequencers. Each sample sequencer can be enabled or disabled independently. ADC Active Sample Sequencer (ADCACTSS) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 ADEN3 RO 0 RO 0 RW 0 24 23 22 21 20 19 18 17 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 5 4 3 2 1 0 ADEN2 ADEN1 ADEN0 ASEN3 ASEN2 ASEN1 ASEN0 RW 0 RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 RO 0 16 BUSY reserved Bit/Field Name Type Reset Description 31:17 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 16 BUSY RO 0 ADC Busy Value Description 0 ADC is idle 1 ADC is busy Note: In order to use the BUSY bit, the ADC Event Multiplexer Select (ADCEMUX) register must be programmed such that no trigger is selected (bit field encoding is 0xE). The NEVER encoding in the ADCEMUX register allows the ADC to safely be put in Deep-Sleep mode. 15:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 ADEN3 RW 0 ADC SS3 DMA Enable Value Description 10 ADEN2 RW 0 0 DMA for Sample Sequencer 3 is disabled. 1 DMA for Sample Sequencer 3 is enabled. ADC SS2 DMA Enable Value Description 0 DMA for Sample Sequencer 2 is disabled. 1 DMA for Sample Sequencer 2 is enabled. June 18, 2014 1077 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 9 ADEN1 RW 0 Description ADC SS1 DMA Enable Value Description 8 ADEN0 RW 0 0 DMA for Sample Sequencer 1 is disabled. 1 DMA for Sample Sequencer 1 is enabled. ADC SS1 DMA Enable Value Description 0 DMA for Sample Sequencer 1 is disabled. 1 DMA for Sample Sequencer 1 is enabled. 7:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 ASEN3 RW 0 ADC SS3 Enable Value Description 2 ASEN2 RW 0 0 Sample Sequencer 3 is disabled. 1 Sample Sequencer 3 is enabled. ADC SS2 Enable Value Description 1 ASEN1 RW 0 0 Sample Sequencer 2 is disabled. 1 Sample Sequencer 2 is enabled. ADC SS1 Enable Value Description 0 ASEN0 RW 0 0 Sample Sequencer 1 is disabled. 1 Sample Sequencer 1 is enabled. ADC SS0 Enable Value Description 0 Sample Sequencer 0 is disabled. 1 Sample Sequencer 0 is enabled. 1078 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: ADC Raw Interrupt Status (ADCRIS), offset 0x004 This register shows the status of the raw interrupt signal of each sample sequencer. These bits may be polled by software to look for interrupt conditions without sending the interrupts to the interrupt controller. ADC Raw Interrupt Status (ADCRIS) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x004 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 24 23 22 21 20 19 18 17 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 INR3 INR2 INR1 INR0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset INRDC DMAINR3 DMAINR2 DMAINR1 DMAINR0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 16 reserved Bit/Field Name Type Reset Description 31:17 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 16 INRDC RO 0 Digital Comparator Raw Interrupt Status Value Description 0 All bits in the ADCDCISC register are clear. 1 At least one bit in the ADCDCISC register is set, meaning that a digital comparator interrupt has occurred. 15:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 DMAINR3 RO 0 SS3 DMA Raw Interrupt Status Value Description 0 The DMA interrupt has not occurred. 1 The sample sequence 3 DMA interrupt is asserted. This bit is cleared by writing a 1 to the DMAINR3 bit in the ADCISC register. 10 DMAINR2 RO 0 SS2 DMA Raw Interrupt Status Value Description 0 The DMA interrupt has not occurred. 1 The sample sequence 2 DMA interrupt is asserted. This bit is cleared by writing a 1 to the DMAINR2 bit in the ADCISC register. June 18, 2014 1079 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 9 DMAINR1 RO 0 Description SS1 DMA Raw Interrupt Status Value Description 0 The DMA interrupt has not occurred. 1 The sample sequence 1 DMA interrupt is asserted. This bit is cleared by writing a 1 to the DMAINR1 bit in the ADCISC register. 8 DMAINR0 RO 0 SS0 DMA Raw Interrupt Status Value Description 0 The DMA interrupt has not occurred. 1 The sample sequence 0 DMA interrupt is asserted. This bit is cleared by writing a 1 to the DMAINR0 bit in the ADCISC register. 7:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 INR3 RO 0 SS3 Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 A sample has completed conversion and the respective ADCSSCTL3 IEn bit is set, enabling a raw interrupt. This bit is cleared by writing a 1 to the IN3 bit in the ADCISC register. 2 INR2 RO 0 SS2 Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 A sample has completed conversion and the respective ADCSSCTL2 IEn bit is set, enabling a raw interrupt. This bit is cleared by writing a 1 to the IN2 bit in the ADCISC register. 1 INR1 RO 0 SS1 Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 A sample has completed conversion and the respective ADCSSCTL1 IEn bit is set, enabling a raw interrupt. This bit is cleared by writing a 1 to the IN1 bit in the ADCISC register. 1080 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 INR0 RO 0 Description SS0 Raw Interrupt Status Value Description 0 An interrupt has not occurred. 1 A sample has completed conversion and the respective ADCSSCTL0 IEn bit is set, enabling a raw interrupt. This bit is cleared by writing a 1 to the IN0 bit in the ADCISC register. June 18, 2014 1081 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 3: ADC Interrupt Mask (ADCIM), offset 0x008 This register controls whether the sample sequencer and digital comparator raw interrupt signals are sent to the interrupt controller. Each raw interrupt signal can be masked independently. Note: For a 1 to 2 Msps rate, as the system clock frequency approaches the ADC clock frequency, it is recommended that the application use the µDMA to store conversion data from the FIFO to memory before processing rather than an interrupt-driven single data read. Using the µDMA to store multiple samples before interrupting the processor amortizes interrupt overhead across multiple transfers and prevents loss of sample data. Note: Only a single DCONSSn bit should be set at any given time. Setting more than one of these bits results in the INRDC bit from the ADCRIS register being masked, and no interrupt is generated on any of the sample sequencer interrupt lines. It is recommended that when interrupts are used, they are enabled on alternating samples or at the end of the sample sequence. ADC Interrupt Mask (ADCIM) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 25 24 23 22 21 20 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 9 8 7 6 5 4 3 2 1 0 MASK3 MASK2 MASK1 MASK0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 RW 0 RW 0 18 17 16 DCONSS3 DCONSS2 DCONSS1 DCONSS0 reserved DMAMASK3 DMAMASK2 DMAMASK1 DMAMASK0 RO 0 19 RW 0 RW 0 Bit/Field Name Type Reset Description 31:20 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 DCONSS3 RW 0 Digital Comparator Interrupt on SS3 Value Description 18 DCONSS2 RW 0 0 The status of the digital comparators does not affect the SS3 interrupt status. 1 The raw interrupt signal from the digital comparators (INRDC bit in the ADCRIS register) is sent to the interrupt controller on the SS3 interrupt line. Digital Comparator Interrupt on SS2 Value Description 0 The status of the digital comparators does not affect the SS2 interrupt status. 1 The raw interrupt signal from the digital comparators (INRDC bit in the ADCRIS register) is sent to the interrupt controller on the SS2 interrupt line. 1082 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 17 DCONSS1 RW 0 Description Digital Comparator Interrupt on SS1 Value Description 16 DCONSS0 RW 0 0 The status of the digital comparators does not affect the SS1 interrupt status. 1 The raw interrupt signal from the digital comparators (INRDC bit in the ADCRIS register) is sent to the interrupt controller on the SS1 interrupt line. Digital Comparator Interrupt on SS0 Value Description 0 The status of the digital comparators does not affect the SS0 interrupt status. 1 The raw interrupt signal from the digital comparators (INRDC bit in the ADCRIS register) is sent to the interrupt controller on the SS0 interrupt line. 15:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 DMAMASK3 RW 0 SS3 DMA Interrupt Mask Value Description 10 DMAMASK2 RW 0 0 The status of Sample Sequencer 3 DMA does not affect the SS3 interrupt status. 1 The raw interrupt signal from Sample Sequencer 3 DMA (ADCRIS register DMAINR3 bit) is sent to the interrupt controller. SS2 DMA Interrupt Mask Value Description 9 DMAMASK1 RW 0 0 The status of Sample Sequencer 2 DMA does not affect the SS2 interrupt status. 1 The raw interrupt signal from Sample Sequencer 2 DMA (ADCRIS register DMAINR2 bit) is sent to the interrupt controller. SS1 DMA Interrupt Mask Value Description 0 The status of Sample Sequencer 1 DMA does not affect the SS1 interrupt status. 1 The raw interrupt signal from Sample Sequencer 1 DMA (ADCRIS register DMAINR1 bit) is sent to the interrupt controller. June 18, 2014 1083 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 8 DMAMASK0 RW 0 Description SS0 DMA Interrupt Mask Value Description 0 The status of Sample Sequencer 0 DMA does not affect the SS0 interrupt status. 1 The raw interrupt signal from Sample Sequencer 0 DMA (ADCRIS register DMAINR0 bit) is sent to the interrupt controller. 7:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 MASK3 RW 0 SS3 Interrupt Mask Value Description 2 MASK2 RW 0 0 The status of Sample Sequencer 3 does not affect the SS3 interrupt status. 1 The raw interrupt signal from Sample Sequencer 3 (ADCRIS register INR3 bit) is sent to the interrupt controller. SS2 Interrupt Mask Value Description 1 MASK1 RW 0 0 The status of Sample Sequencer 2 does not affect the SS2 interrupt status. 1 The raw interrupt signal from Sample Sequencer 2 (ADCRIS register INR2 bit) is sent to the interrupt controller. SS1 Interrupt Mask Value Description 0 MASK0 RW 0 0 The status of Sample Sequencer 1 does not affect the SS1 interrupt status. 1 The raw interrupt signal from Sample Sequencer 1 (ADCRIS register INR1 bit) is sent to the interrupt controller. SS0 Interrupt Mask Value Description 0 The status of Sample Sequencer 0 does not affect the SS0 interrupt status. 1 The raw interrupt signal from Sample Sequencer 0 (ADCRIS register INR0 bit) is sent to the interrupt controller. 1084 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 4: ADC Interrupt Status and Clear (ADCISC), offset 0x00C This register provides the mechanism for clearing sample sequencer interrupt conditions and shows the status of interrupts generated by the sample sequencers and the digital comparators which have been sent to the interrupt controller. When read, each bit field is the logical AND of the respective INR and MASK bits. Sample sequencer interrupts are cleared by writing a 1 to the corresponding bit position. Digital comparator interrupts are cleared by writing a 1 to the appropriate bits in the ADCDCISC register. If software is polling the ADCRIS instead of generating interrupts, the sample sequence INRn bits are still cleared via the ADCISC register, even if the INn bit is not set. ADC Interrupt Status and Clear (ADCISC) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x00C Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 25 24 23 22 21 20 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 10 9 8 7 6 5 4 3 2 1 0 DMAIN3 DMAIN2 DMAIN1 DMAIN0 IN3 IN2 IN1 IN0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 RO 0 RO 0 RO 0 RO 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 reserved Type Reset reserved Type Reset RO 0 RO 0 19 18 17 16 DCINSS3 DCINSS2 DCINSS1 DCINSS0 reserved Bit/Field Name Type Reset Description 31:20 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 DCINSS3 RO 0 Digital Comparator Interrupt Status on SS3 Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INRDC bit in the ADCRIS register and the DCONSS3 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1 to it. Clearing this bit also clears the INRDC bit in the ADCRIS register. 18 DCINSS2 RO 0 Digital Comparator Interrupt Status on SS2 Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INRDC bit in the ADCRIS register and the DCONSS2 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1 to it. Clearing this bit also clears the INRDC bit in the ADCRIS register. June 18, 2014 1085 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 17 DCINSS1 RO 0 Description Digital Comparator Interrupt Status on SS1 Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INRDC bit in the ADCRIS register and the DCONSS1 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1 to it. Clearing this bit also clears the INRDC bit in the ADCRIS register. 16 DCINSS0 RO 0 Digital Comparator Interrupt Status on SS0 Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INRDC bit in the ADCRIS register and the DCONSS0 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1 to it. Clearing this bit also clears the INRDC bit in the ADCRIS register. 15:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 DMAIN3 RW1C 0 SS3 DMA Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the DMAINR3 bit in the ADCRIS register and the DMAMASK3 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the DMAINR3 bit in the ADCRIS register. 10 DMAIN2 RW1C 0 SS2 DMA Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the DMAINR2 bit in the ADCRIS register and the DMAMASK2 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the DMAINR2 bit in the ADCRIS register. 1086 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 9 DMAIN1 RW1C 0 Description SS1 DMA Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the DMAINR1 bit in the ADCRIS register and the DMAMASK1 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the DMAINR1 bit in the ADCRIS register. 8 DMAIN0 RW1C 0 SS0 DMA Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the DMAINR0 bit in the ADCRIS register and the DMAMASK0 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the DMAINR0 bit in the ADCRIS register. 7:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 IN3 RW1C 0 SS3 Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INR3 bit in the ADCRIS register and the MASK3 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INR3 bit in the ADCRIS register. 2 IN2 RW1C 0 SS2 Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INR2 bit in the ADCRIS register and the MASK2 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INR2 bit in the ADCRIS register. June 18, 2014 1087 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 1 IN1 RW1C 0 Description SS1 Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INR1 bit in the ADCRIS register and the MASK1 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INR1 bit in the ADCRIS register. 0 IN0 RW1C 0 SS0 Interrupt Status and Clear Value Description 0 No interrupt has occurred or the interrupt is masked. 1 Both the INR0 bit in the ADCRIS register and the MASK0 bit in the ADCIM register are set, providing a level-based interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INR0 bit in the ADCRIS register. 1088 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: ADC Overflow Status (ADCOSTAT), offset 0x010 This register indicates overflow conditions in the sample sequencer FIFOs. Once the overflow condition has been handled by software, the condition can be cleared by writing a 1 to the corresponding bit position. ADC Overflow Status (ADCOSTAT) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x010 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 OV3 OV2 OV1 OV0 RO 0 RO 0 RO 0 RO 0 RO 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 OV3 RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. SS3 FIFO Overflow Value Description 0 The FIFO has not overflowed. 1 The FIFO for Sample Sequencer 3 has hit an overflow condition, meaning that the FIFO is full and a write was requested. When an overflow is detected, the most recent write is dropped. This bit is cleared by writing a 1. 2 OV2 RW1C 0 SS2 FIFO Overflow Value Description 0 The FIFO has not overflowed. 1 The FIFO for Sample Sequencer 2 has hit an overflow condition, meaning that the FIFO is full and a write was requested. When an overflow is detected, the most recent write is dropped. This bit is cleared by writing a 1. 1 OV1 RW1C 0 SS1 FIFO Overflow Value Description 0 The FIFO has not overflowed. 1 The FIFO for Sample Sequencer 1 has hit an overflow condition, meaning that the FIFO is full and a write was requested. When an overflow is detected, the most recent write is dropped. This bit is cleared by writing a 1. June 18, 2014 1089 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 0 OV0 RW1C 0 Description SS0 FIFO Overflow Value Description 0 The FIFO has not overflowed. 1 The FIFO for Sample Sequencer 0 has hit an overflow condition, meaning that the FIFO is full and a write was requested. When an overflow is detected, the most recent write is dropped. This bit is cleared by writing a 1. 1090 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 6: ADC Event Multiplexer Select (ADCEMUX), offset 0x014 The ADCEMUX selects the event (trigger) that initiates sampling for each sample sequencer. Each sample sequencer can be configured with a unique trigger source. ADC Event Multiplexer Select (ADCEMUX) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x014 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset EM3 Type Reset EM2 EM1 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 EM0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1091 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 15:12 EM3 RW 0x0 Description SS3 Trigger Select This field selects the trigger source for Sample Sequencer 3. The valid configurations for this field are: Value Event 0x0 Processor (default) The trigger is initiated by setting the SSn bit in the ADCPSSI register. 0x1 Analog Comparator 0 This trigger is configured by the Analog Comparator Control 0 (ACCTL0) register (page 1665). 0x2 Analog Comparator 1 This trigger is configured by the Analog Comparator Control 1 (ACCTL1) register (page 1665). 0x3 Analog Comparator 2 This trigger is configured by the Analog Comparator Control 2 (ACCTL2) register (page 1665). 0x4 External (GPIO Pins) This trigger is connected to the GPIO interrupt for the corresponding GPIO (see “ADC Trigger Source” on page 750). 0x5 Timer In addition, the trigger must be enabled with the TnOTE bit in the GPTMCTL register (page 986). 0x6 PWM generator 0 The PWM generator 0 trigger can be configured with the PWM0 Interrupt and Trigger Enable (PWM0INTEN) register (page 1713). 0x7 PWM generator 1 The PWM generator 1 trigger can be configured with the PWM1INTEN register (page 1713). 0x8 PWM generator 2 The PWM generator 2 trigger can be configured with the PWM2INTEN register (page 1713). 0x9 PWM generator 3 The PWM generator 3 trigger can be configured with the PWM3INTEN register (page 1713). 0xA-0xD reserved 0xE Never Trigger (No triggers are allowed to the ADC digital interface) 0xF Always (continuously sample) 1092 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 11:8 EM2 RW 0x0 Description SS2 Trigger Select This field selects the trigger source for Sample Sequencer 2. The valid configurations for this field are: Value Event 0x0 Processor (default) The trigger is initiated by setting the SSn bit in the ADCPSSI register. 0x1 Analog Comparator 0 This trigger is configured by the Analog Comparator Control 0 (ACCTL0) register (page 1665). 0x2 Analog Comparator 1 This trigger is configured by the Analog Comparator Control 1 (ACCTL1) register (page 1665). 0x3 Analog Comparator 2 This trigger is configured by the Analog Comparator Control 2 (ACCTL2) register (page 1665). 0x4 External (GPIO Pins) This trigger is connected to the GPIO interrupt for the corresponding GPIO (see “ADC Trigger Source” on page 750). 0x5 Timer In addition, the trigger must be enabled with the TnOTE bit in the GPTMCTL register (page 986). 0x6 PWM generator 0 The PWM generator 0 trigger can be configured with the PWM0 Interrupt and Trigger Enable (PWM0INTEN) register (page 1713). 0x7 PWM generator 1 The PWM generator 1 trigger can be configured with the PWM1INTEN register (page 1713). 0x8 PWM generator 2 The PWM generator 2 trigger can be configured with the PWM2INTEN register (page 1713). 0x9 PWM generator 3 The PWM generator 3 trigger can be configured with the PWM3INTEN register (page 1713). 0xA-0xD reserved 0xE Never Trigger (No triggers are allowed to the ADC digital interface) 0xF Always (continuously sample) June 18, 2014 1093 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 7:4 EM1 RW 0x0 Description SS1 Trigger Select This field selects the trigger source for Sample Sequencer 1. The valid configurations for this field are: Value Event 0x0 Processor (default) The trigger is initiated by setting the SSn bit in the ADCPSSI register. 0x1 Analog Comparator 0 This trigger is configured by the Analog Comparator Control 0 (ACCTL0) register (page 1665). 0x2 Analog Comparator 1 This trigger is configured by the Analog Comparator Control 1 (ACCTL1) register (page 1665). 0x3 Analog Comparator 2 This trigger is configured by the Analog Comparator Control 2 (ACCTL2) register (page 1665). 0x4 External (GPIO Pins) This trigger is connected to the GPIO interrupt for the corresponding GPIO (see “ADC Trigger Source” on page 750). 0x5 Timer In addition, the trigger must be enabled with the TnOTE bit in the GPTMCTL register (page 986). 0x6 PWM generator 0 The PWM generator 0 trigger can be configured with the PWM0 Interrupt and Trigger Enable (PWM0INTEN) register (page 1713). 0x7 PWM generator 1 The PWM generator 1 trigger can be configured with the PWM1INTEN register (page 1713). 0x8 PWM generator 2 The PWM generator 2 trigger can be configured with the PWM2INTEN register (page 1713). 0x9 PWM generator 3 The PWM generator 3 trigger can be configured with the PWM3INTEN register (page 1713). 0xA-0xD reserved 0xE Never Trigger (No triggers are allowed to the ADC digital interface) 0xF Always (continuously sample) 1094 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3:0 EM0 RW 0x0 Description SS0 Trigger Select This field selects the trigger source for Sample Sequencer 0 The valid configurations for this field are: Value Event 0x0 Processor (default) The trigger is initiated by setting the SSn bit in the ADCPSSI register. 0x1 Analog Comparator 0 This trigger is configured by the Analog Comparator Control 0 (ACCTL0) register (page 1665). 0x2 Analog Comparator 1 This trigger is configured by the Analog Comparator Control 1 (ACCTL1) register (page 1665). 0x3 Analog Comparator 2 This trigger is configured by the Analog Comparator Control 2 (ACCTL2) register (page 1665). 0x4 External (GPIO Pins) This trigger is connected to the GPIO interrupt for the corresponding GPIO (see “ADC Trigger Source” on page 750). 0x5 Timer In addition, the trigger must be enabled with the TnOTE bit in the GPTMCTL register (page 986). 0x6 PWM generator 0 The PWM generator 0 trigger can be configured with the PWM0 Interrupt and Trigger Enable (PWM0INTEN) register (page 1713). 0x7 PWM generator 1 The PWM generator 1 trigger can be configured with the PWM1INTEN register (page 1713). 0x8 PWM generator 2 The PWM generator 2 trigger can be configured with the PWM2INTEN register (page 1713). 0x9 PWM generator 3 The PWM generator 3 trigger can be configured with the PWM3INTEN register (page 1713). 0xA-0xD reserved 0xE Never Trigger (No triggers are allowed to the ADC digital interface) 0xF Always (continuously sample) June 18, 2014 1095 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 7: ADC Underflow Status (ADCUSTAT), offset 0x018 This register indicates underflow conditions in the sample sequencer FIFOs. The corresponding underflow condition is cleared by writing a 1 to the relevant bit position. ADC Underflow Status (ADCUSTAT) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x018 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 UV3 UV2 UV1 UV0 RO 0 RO 0 RO 0 RO 0 RO 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 UV3 RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. SS3 FIFO Underflow The valid configurations for this field are shown below. This bit is cleared by writing a 1. Value Description 2 UV2 RW1C 0 0 The FIFO has not underflowed. 1 The FIFO for the Sample Sequencer has hit an underflow condition, meaning that the FIFO is empty and a read was requested. The problematic read does not move the FIFO pointers, and 0s are returned. SS2 FIFO Underflow The valid configurations are the same as those for the UV3 field. This bit is cleared by writing a 1. 1 UV1 RW1C 0 SS1 FIFO Underflow The valid configurations are the same as those for the UV3 field. This bit is cleared by writing a 1. 0 UV0 RW1C 0 SS0 FIFO Underflow The valid configurations are the same as those for the UV3 field. This bit is cleared by writing a 1. 1096 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: ADC Trigger Source Select (ADCTSSEL), offset 0x01C If a PWM Generator n is selected as a trigger source through the EMn bit field in the ADC Event Multiplexer Select (ADCEMUX) register, the ADCTSSEL register is programmed to identify in which PWM module instance the generator creating the trigger is located. The register resets to 0x0000.0000, which selects PWM module 0 for all generators. Note that field PS3 selects the PWM module that maps to Generator 3; PS2 selects the PWM module that maps to Generator 2, and so on. ADC Trigger Source Select (ADCTSSEL) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x01C Type RW, reset 0x0000.0000 31 30 29 reserved Type Reset 27 26 25 PS3 24 23 22 21 reserved 20 19 18 PS2 17 16 reserved RO 0 RO 0 RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset 28 RO 0 RO 0 PS1 RW 0 reserved PS0 reserved Bit/Field Name Type Reset Description 31:30 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 29:28 PS3 RW 0x0 Generator 3 PWM Module Trigger Select This field selects in which PWM module the generator 3 trigger is located. Value Description 0x0 Use Generator 3 (and its trigger) in PWM module 0 0x1-0x3 reserved 27:22 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 21:20 PS2 RW 0x0 Generator 2 PWM Module Trigger Select This field selects in which PWM module the Generator 2 trigger is located. Value Description 0x0 Use Generator 2 (and its trigger) in PWM module 0 0x1-0x3 reserved 19:14 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1097 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 13:12 PS1 RW 0x0 Description Generator 1 PWM Module Trigger Select This field selects in which PWM module the Generator 1 trigger is located. Value Description 0x0 Use Generator 1 (and its trigger) in PWM module 0 0x1-0x3 reserved 11:6 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5:4 PS0 RW 0x0 Generator 0 PWM Module Trigger Select This field selects in which PWM module the Generator 0 trigger is located. Value Description 0x0 Use Generator 0 (and its trigger) in PWM module 0 0x1-0x3 reserved 3:0 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1098 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 9: ADC Sample Sequencer Priority (ADCSSPRI), offset 0x020 This register sets the priority for each of the sample sequencers. Out of reset, Sequencer 0 has the highest priority, and Sequencer 3 has the lowest priority. When reconfiguring sequence priorities, each sequence must have a unique priority for the ADC to operate properly. ADC Sample Sequencer Priority (ADCSSPRI) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x020 Type RW, reset 0x0000.3210 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RW 1 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RO 0 RO 0 RW 0 RW 1 RO 0 RO 0 RW 0 reserved Type Reset reserved Type Reset RO 0 RO 0 SS3 RW 1 reserved RO 0 SS2 RW 1 Bit/Field Name Type Reset 31:14 reserved RO 0x0000.0 13:12 SS3 RW 0x3 reserved SS1 reserved SS0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. SS3 Priority This field contains a binary-encoded value that specifies the priority encoding of Sample Sequencer 3. A priority encoding of 0x0 is highest and 0x3 is lowest. The priorities assigned to the sequencers must be uniquely mapped. The ADC may not operate properly if two or more fields are equal. 11:10 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 9:8 SS2 RW 0x2 SS2 Priority This field contains a binary-encoded value that specifies the priority encoding of Sample Sequencer 2. A priority encoding of 0x0 is highest and 0x3 is lowest. The priorities assigned to the sequencers must be uniquely mapped. The ADC may not operate properly if two or more fields are equal. 7:6 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5:4 SS1 RW 0x1 SS1 Priority This field contains a binary-encoded value that specifies the priority encoding of Sample Sequencer 1. A priority encoding of 0x0 is highest and 0x3 is lowest. The priorities assigned to the sequencers must be uniquely mapped. The ADC may not operate properly if two or more fields are equal. 3:2 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1099 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset Description 1:0 SS0 RW 0x0 SS0 Priority This field contains a binary-encoded value that specifies the priority encoding of Sample Sequencer 0. A priority encoding of 0x0 is highest and 0x3 is lowest. The priorities assigned to the sequencers must be uniquely mapped. The ADC may not operate properly if two or more fields are equal. 1100 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 10: ADC Sample Phase Control (ADCSPC), offset 0x024 The ADC Sample Phase Control (ADCSPC) register is used to insert a delay in ADC module sampling. This feature can be used with the SYNCWAIT and GSYNC bit in the ADCPSSI register to provide concurrent sampling of two different signals by two different ADC modules or skewed sampling of two ADC modules to increase the effective sampling rate. For concurrent sampling, the PHASE field of each ADC module must be the same and the sample and hold times (TSHn) for the matching sample steps of each ADC must be the same. For example, both ADC0 and ADC1 would program PHASE = 0x0 in the ADCSPC register and might both have the following configuration for their ADCSSTSH0 register: ■ TSH7=0x4 ■ TSH6=0x2 ■ TSH5=0x2 ■ TSH4=0x8 ■ TSH3=0x6 ■ TSH2=0x2 ■ TSH1=0x4 ■ TSH0=0x2 For skewed sampling with a consistent phase lag, the TSHn field in the ADCSSTSHn register must be the same for all sample steps of an ADC and for both ADC Modules. The desired lag can be calculated by adding the sample and hold time (TSHn) to the twelve clock conversion time to determine the total number of clocks in a sample period. For example to create a 180.0° phase lag, the PHASE of the lagging ADC is calculated as: PHASE = (TSHn+ 12)/2, where TSHn is in ADC_Clocks For situations where a predictable phase lag is not required, sample and hold times (TSHn) of ADC modules can vary. Note: Care should be taken when the PHASE field is non-zero, as the resulting delay in sampling the AINx input may result in undesirable system consequences. The time from ADC trigger to sample is increased and could make the response time longer than anticipated. The added latency could have ramifications in the system design. Designers should carefully consider the impact of this delay. June 18, 2014 1101 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) ADC Sample Phase Control (ADCSPC) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 PHASE RW 0x0 PHASE Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Phase Lag This field selects the sample phase lag from the standard sample time. Value Description 0x0 The ADC samples are concurrent. 0x1 The ADC sample lags by 1 ADC clock 0x2 The ADC sample lags by 2 ADC clocks 0x3 The ADC sample lags by 3 ADC clocks 0x4 The ADC sample lags by 4 clocks 0x5 The ADC sample lags by 5 clocks 0x6 The ADC sample lags by 6 clocks 0x7 The ADC sample lags by 7 clocks 0x8 The ADC sample lags by 8 clocks 0x9 The ADC sample lags by 9 clocks 0xA The ADC sample lags by 10 clocks 0xB The ADC sample lags by 11 clocks 0xC The ADC sample lags by 12 clocks 0xD The ADC sample lags by 13 clocks 0xE The ADC sample lags by 14 clocks 0xF The ADC sample lags by 15 clocks 1102 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: ADC Processor Sample Sequence Initiate (ADCPSSI), offset 0x028 This register provides a mechanism for application software to initiate sampling in the sample sequencers. Sample sequences can be initiated individually or in any combination. When multiple sequences are triggered simultaneously, the priority encodings in ADCSSPRI dictate execution order. This register also provides a means to configure and then initiate concurrent sampling on all ADC modules. To do this, the first ADC module should be configured. The ADCPSSI register for that module should then be written. The appropriate SS bits should be set along with the SYNCWAIT bit. Additional ADC modules should then be configured following the same procedure. Once the final ADC module is configured, its ADCPSSI register should be written with the appropriate SS bits set along with the GSYNC bit. All of the ADC modules then begin concurrent sampling according to their configuration. ADC Processor Sample Sequence Initiate (ADCPSSI) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x028 Type RW, reset 31 30 GSYNC Type Reset 29 28 reserved 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 reserved SYNCWAIT RW 0 RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31 GSYNC RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 SS3 SS2 SS1 SS0 WO - WO - WO - WO - Description Global Synchronize Value Description 30:28 reserved RO 0x0 27 SYNCWAIT RW 0 0 This bit is cleared once sampling has been initiated. 1 This bit initiates sampling in multiple ADC modules at the same time. Any ADC module that has been initialized by setting an SSn bit and the SYNCWAIT bit starts sampling once this bit is written. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Synchronize Wait Value Description 26:4 reserved RO 0x0000.0 0 Sampling begins when a sample sequence has been initiated. 1 This bit allows the sample sequences to be initiated, but delays sampling until the GSYNC bit is set. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1103 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset Description 3 SS3 WO - SS3 Initiate Value Description 0 No effect. 1 Begin sampling on Sample Sequencer 3, if the sequencer is enabled in the ADCACTSS register. Only a write by software is valid; a read of this register returns no meaningful data. 2 SS2 WO - SS2 Initiate Value Description 0 No effect. 1 Begin sampling on Sample Sequencer 2, if the sequencer is enabled in the ADCACTSS register. Only a write by software is valid; a read of this register returns no meaningful data. 1 SS1 WO - SS1 Initiate Value Description 0 No effect. 1 Begin sampling on Sample Sequencer 1, if the sequencer is enabled in the ADCACTSS register. Only a write by software is valid; a read of this register returns no meaningful data. 0 SS0 WO - SS0 Initiate Value Description 0 No effect. 1 Begin sampling on Sample Sequencer 0, if the sequencer is enabled in the ADCACTSS register. Only a write by software is valid; a read of this register returns no meaningful data. 1104 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 12: ADC Sample Averaging Control (ADCSAC), offset 0x030 This register controls the amount of hardware averaging applied to conversion results. The final conversion result stored in the FIFO is averaged from 2 AVG consecutive ADC samples at the specified ADC speed. If AVG is 0, the sample is passed directly through without any averaging. If AVG=6, then 64 consecutive ADC samples are averaged to generate one result in the sequencer FIFO. An AVG=7 provides unpredictable results. ADC Sample Averaging Control (ADCSAC) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x030 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:3 reserved RO 0x0000.000 2:0 AVG RW 0x0 AVG RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Hardware Averaging Control Specifies the amount of hardware averaging that will be applied to ADC samples. The AVG field can be any value between 0 and 6. Entering a value of 7 creates unpredictable results. Value Description 0x0 No hardware oversampling 0x1 2x hardware oversampling 0x2 4x hardware oversampling 0x3 8x hardware oversampling 0x4 16x hardware oversampling 0x5 32x hardware oversampling 0x6 64x hardware oversampling 0x7 reserved June 18, 2014 1105 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 13: ADC Digital Comparator Interrupt Status and Clear (ADCDCISC), offset 0x034 This register provides status and acknowledgement of digital comparator interrupts. One bit is provided for each comparator. ADC Digital Comparator Interrupt Status and Clear (ADCDCISC) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x034 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 DCINT7 RW1C 0 RO 0 RO 0 7 6 5 4 3 2 1 0 DCINT7 DCINT6 DCINT5 DCINT4 DCINT3 DCINT2 DCINT1 DCINT0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Digital Comparator 7 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 7 has generated an interrupt. This bit is cleared by writing a 1. 6 DCINT6 RW1C 0 Digital Comparator 6 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 6 has generated an interrupt. This bit is cleared by writing a 1. 5 DCINT5 RW1C 0 Digital Comparator 5 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 5 has generated an interrupt. This bit is cleared by writing a 1. 1106 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 DCINT4 RW1C 0 Description Digital Comparator 4 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 4 has generated an interrupt. This bit is cleared by writing a 1. 3 DCINT3 RW1C 0 Digital Comparator 3 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 3 has generated an interrupt. This bit is cleared by writing a 1. 2 DCINT2 RW1C 0 Digital Comparator 2 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 2 has generated an interrupt. This bit is cleared by writing a 1. 1 DCINT1 RW1C 0 Digital Comparator 1 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 1 has generated an interrupt. This bit is cleared by writing a 1. 0 DCINT0 RW1C 0 Digital Comparator 0 Interrupt Status and Clear Value Description 0 No interrupt. 1 Digital Comparator 0 has generated an interrupt. This bit is cleared by writing a 1. June 18, 2014 1107 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 14: ADC Control (ADCCTL), offset 0x038 This register configures the voltage reference. The voltage references for the conversion can be VREFA+ and GNDA or VDDA and GNDA. Note that values set in this register apply to all ADC modules, it is not possible to set one module to use internal references and another to use external references. ADC Control (ADCCTL) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x038 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 VREF RW 0x0 RO 0 VREF RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Voltage Reference Select Value Description 0x0 VDDA and GNDA are the voltage references for all ADC modules. 0x1 The external VREFA+ and GNDA are the voltage references for all ADC modules. 1108 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 15: ADC Sample Sequence Input Multiplexer Select 0 (ADCSSMUX0), offset 0x040 This register, along with the ADCSSEMUX0 register, defines the analog input configuration for each sample in a sequence executed with Sample Sequencer 0. If the corresponding EMUXn bit in the ADCSSEMUX0 register is set, the MUXn field in this register selects from AIN[19:16]. When the corresponding EMUXn bit is clear, the MUXn field selects from AIN[15:0]. This register is 32 bits wide and contains information for eight possible samples. Note: Channels AIN[31:20] do not exist on this microcontroller. Configuring MUXn to be 0xC-0xF when the corresponding EMUXn bit is set results in undefined behavior. ADC Sample Sequence Input Multiplexer Select 0 (ADCSSMUX0) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x040 Type RW, reset 0x0000.0000 31 30 29 28 27 26 RW 0 25 24 23 22 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 MUX7 Type Reset 20 19 18 RW 0 RW 0 RW 0 RW 0 7 6 5 4 RW 0 RW 0 RW 0 RW 0 MUX6 MUX3 Type Reset 21 17 16 RW 0 RW 0 RW 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 MUX5 MUX2 MUX4 MUX1 Bit/Field Name Type Reset 31:28 MUX7 RW 0x0 MUX0 Description 8th Sample Input Select The MUX7 field is used during the eighth sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. The value set here indicates the corresponding pin, for example, a value of 0x1 when EMUX7 is clear indicates the input is AIN1. A value of 0x1 when EMUX7 is set indicates the input is AIN17. If differential sampling is enabled (the D7 bit in the ADCSSCTL0 register is set), this field must be set to the pair number "i", where the paired inputs are "2i and 2i+1". 27:24 MUX6 RW 0x0 7th Sample Input Select The MUX6 field is used during the seventh sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. 23:20 MUX5 RW 0x0 6th Sample Input Select The MUX5 field is used during the sixth sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. 19:16 MUX4 RW 0x0 5th Sample Input Select The MUX4 field is used during the fifth sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. June 18, 2014 1109 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 15:12 MUX3 RW 0x0 Description 4th Sample Input Select The MUX3 field is used during the fourth sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. 11:8 MUX2 RW 0x0 3rd Sample Input Select The MUX2 field is used during the third sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. 7:4 MUX1 RW 0x0 2nd Sample Input Select The MUX1 field is used during the second sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. 3:0 MUX0 RW 0x0 1st Sample Input Select The MUX0 field is used during the first sample of a sequence executed with the sample sequencer. It specifies which of the analog inputs is sampled for the analog-to-digital conversion. 1110 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 16: ADC Sample Sequence Control 0 (ADCSSCTL0), offset 0x044 This register contains the configuration information for each sample for a sequence executed with a sample sequencer. When configuring a sample sequence, the END bit must be set for the final sample, whether it be after the first sample, eighth sample, or any sample in between. This register is 32 bits wide and contains information for eight possible samples. ADC Sample Sequence Control 0 (ADCSSCTL0) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x044 Type RW, reset 0x0000.0000 31 Type Reset Type Reset 30 29 28 27 26 25 TS7 IE7 RW 0 RW 0 15 24 23 END7 D7 RW 0 RW 0 14 13 TS3 IE3 RW 0 RW 0 22 21 TS6 IE6 RW 0 RW 0 12 11 END3 D3 RW 0 RW 0 END6 D6 RW 0 RW 0 TS5 IE5 RW 0 RW 0 10 9 8 7 TS2 IE2 RW 0 RW 0 END2 D2 RW 0 RW 0 Bit/Field Name Type Reset 31 TS7 RW 0 20 19 18 17 END5 D5 RW 0 RW 0 6 5 TS1 IE1 RW 0 RW 0 16 TS4 IE4 END4 D4 RW 0 RW 0 RW 0 RW 0 4 3 2 1 0 END1 D1 TS0 IE0 END0 D0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Description 8th Sample Temp Sensor Select Value Description 30 IE7 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the eighth sample of the sample sequence. 1 The temperature sensor is read during the eighth sample of the sample sequence. 8th Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the eighth sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 29 END7 RW 0 8th Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The eighth sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. June 18, 2014 1111 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 28 D7 RW 0 Description 8th Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS7 bit is set. 27 TS6 RW 0 7th Sample Temp Sensor Select Value Description 26 IE6 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the seventh sample of the sample sequence. 1 The temperature sensor is read during the seventh sample of the sample sequence. 7th Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the seventh sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 25 END6 RW 0 7th Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The seventh sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 24 D6 RW 0 7th Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS6 bit is set. 1112 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 23 TS5 RW 0 Description 6th Sample Temp Sensor Select Value Description 22 IE5 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the sixth sample of the sample sequence. 1 The temperature sensor is read during the sixth sample of the sample sequence. 6th Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the sixth sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 21 END5 RW 0 6th Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The sixth sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 20 D5 RW 0 6th Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS5 bit is set. 19 TS4 RW 0 5th Sample Temp Sensor Select Value Description 0 The input pin specified by the ADCSSMUXn register is read during the fifth sample of the sample sequence. 1 The temperature sensor is read during the fifth sample of the sample sequence. June 18, 2014 1113 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 18 IE4 RW 0 Description 5th Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the fifth sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 17 END4 RW 0 5th Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The fifth sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 16 D4 RW 0 5th Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS4 bit is set. 15 TS3 RW 0 4th Sample Temp Sensor Select Value Description 14 IE3 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the fourth sample of the sample sequence. 1 The temperature sensor is read during the fourth sample of the sample sequence. 4th Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the fourth sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 1114 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 13 END3 RW 0 Description 4th Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The fourth sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 12 D3 RW 0 4th Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS3 bit is set. 11 TS2 RW 0 3rd Sample Temp Sensor Select Value Description 10 IE2 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the third sample of the sample sequence. 1 The temperature sensor is read during the third sample of the sample sequence. 3rd Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the third sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 9 END2 RW 0 3rd Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The third sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. June 18, 2014 1115 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 8 D2 RW 0 Description 3rd Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS2 bit is set. 7 TS1 RW 0 2nd Sample Temp Sensor Select Value Description 6 IE1 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the second sample of the sample sequence. 1 The temperature sensor is read during the second sample of the sample sequence. 2nd Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the second sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 5 END1 RW 0 2nd Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The second sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 4 D1 RW 0 2nd Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS1 bit is set. 1116 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 TS0 RW 0 Description 1st Sample Temp Sensor Select Value Description 2 IE0 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the first sample of the sample sequence. 1 The temperature sensor is read during the first sample of the sample sequence. 1st Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the first sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 1 END0 RW 0 1st Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The first sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 0 D0 RW 0 1st Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS0 bit is set. June 18, 2014 1117 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 17: ADC Sample Sequence Result FIFO 0 (ADCSSFIFO0), offset 0x048 Register 18: ADC Sample Sequence Result FIFO 1 (ADCSSFIFO1), offset 0x068 Register 19: ADC Sample Sequence Result FIFO 2 (ADCSSFIFO2), offset 0x088 Register 20: ADC Sample Sequence Result FIFO 3 (ADCSSFIFO3), offset 0x0A8 Important: This register is read-sensitive. See the register description for details. This register contains the conversion results for samples collected with the sample sequencer (the ADCSSFIFO0 register is used for Sample Sequencer 0, ADCSSFIFO1 for Sequencer 1, ADCSSFIFO2 for Sequencer 2, and ADCSSFIFO3 for Sequencer 3). Reads of this register return conversion result data in the order sample 0, sample 1, and so on, until the FIFO is empty. If the FIFO is not properly handled by software, overflow and underflow conditions are registered in the ADCOSTAT and ADCUSTAT registers. ADC Sample Sequence Result FIFO n (ADCSSFIFOn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x048 Type RO, reset 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 RO - RO - RO - RO - RO - RO - reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 reserved Type Reset RO 0 RO 0 DATA RO 0 RO 0 RO - RO - RO - Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 11:0 DATA RO - RO - RO - RO - Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Conversion Result Data 1118 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 21: ADC Sample Sequence FIFO 0 Status (ADCSSFSTAT0), offset 0x04C Register 22: ADC Sample Sequence FIFO 1 Status (ADCSSFSTAT1), offset 0x06C Register 23: ADC Sample Sequence FIFO 2 Status (ADCSSFSTAT2), offset 0x08C Register 24: ADC Sample Sequence FIFO 3 Status (ADCSSFSTAT3), offset 0x0AC This register provides a window into the sample sequencer, providing full/empty status information as well as the positions of the head and tail pointers. The reset value of 0x100 indicates an empty FIFO with the head and tail pointers both pointing to index 0. The ADCSSFSTAT0 register provides status on FIFO0, which has 8 entries; ADCSSFSTAT1 on FIFO1, which has 4 entries; ADCSSFSTAT2 on FIFO2, which has 4 entries; and ADCSSFSTAT3 on FIFO3 which has a single entry. ADC Sample Sequence FIFO n Status (ADCSSFSTATn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x04C Type RO, reset 0x0000.0100 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 RO 0 FULL RO 0 RO 0 reserved RO 0 RO 0 EMPTY RO 0 Bit/Field Name Type Reset 31:13 reserved RO 0x0000.0 12 FULL RO 0 RO 1 HPTR TPTR Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. FIFO Full Value Description 11:9 reserved RO 0x0 8 EMPTY RO 1 0 The FIFO is not currently full. 1 The FIFO is currently full. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. FIFO Empty Value Description 0 The FIFO is not currently empty. 1 The FIFO is currently empty. June 18, 2014 1119 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 7:4 HPTR RO 0x0 Description FIFO Head Pointer This field contains the current "head" pointer index for the FIFO, that is, the next entry to be written. Valid values are 0x0-0x7 for FIFO0; 0x0-0x3 for FIFO1 and FIFO2; and 0x0 for FIFO3. 3:0 TPTR RO 0x0 FIFO Tail Pointer This field contains the current "tail" pointer index for the FIFO, that is, the next entry to be read. Valid values are 0x0-0x7 for FIFO0; 0x0-0x3 for FIFO1 and FIFO2; and 0x0 for FIFO3. 1120 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 25: ADC Sample Sequence 0 Operation (ADCSSOP0), offset 0x050 This register determines whether the sample from the given conversion on Sample Sequence 0 is saved in the Sample Sequence FIFO0 or sent to the digital comparator unit. ADC Sample Sequence 0 Operation (ADCSSOP0) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x050 Type RW, reset 0x0000.0000 31 30 29 reserved Type Reset 27 S7DCOP 26 25 reserved 24 23 S6DCOP 22 21 reserved 20 19 S5DCOP 18 17 reserved 16 S4DCOP RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 reserved Type Reset 28 RO 0 RO 0 S3DCOP RO 0 RW 0 reserved RO 0 RO 0 S2DCOP RO 0 Bit/Field Name Type Reset 31:29 reserved RO 0x0 28 S7DCOP RW 0 RW 0 reserved RO 0 RO 0 S1DCOP RO 0 RW 0 reserved RO 0 RO 0 S0DCOP RO 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 7 Digital Comparator Operation Value Description 27:25 reserved RO 0x0 24 S6DCOP RW 0 0 The eighth sample is saved in Sample Sequence FIFO0. 1 The eighth sample is sent to the digital comparator unit specified by the S7DCSEL bit in the ADCSSDC0 register, and the value is not written to the FIFO. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 6 Digital Comparator Operation Same definition as S7DCOP but used during the seventh sample. 23:21 reserved RO 0x0 20 S5DCOP RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 5 Digital Comparator Operation Same definition as S7DCOP but used during the sixth sample. 19:17 reserved RO 0x0 16 S4DCOP RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 4 Digital Comparator Operation Same definition as S7DCOP but used during the fifth sample. 15:13 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1121 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 12 S3DCOP RW 0 Description Sample 3 Digital Comparator Operation Same definition as S7DCOP but used during the fourth sample. 11:9 reserved RO 0x0 8 S2DCOP RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 2 Digital Comparator Operation Same definition as S7DCOP but used during the third sample. 7:5 reserved RO 0x0 4 S1DCOP RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 1 Digital Comparator Operation Same definition as S7DCOP but used during the second sample. 3:1 reserved RO 0x0 0 S0DCOP RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 0 Digital Comparator Operation Same definition as S7DCOP but used during the first sample. 1122 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 26: ADC Sample Sequence 0 Digital Comparator Select (ADCSSDC0), offset 0x054 This register determines which digital comparator receives the sample from the given conversion on Sample Sequence 0, if the corresponding SnDCOP bit in the ADCSSOP0 register is set. ADC Sample Sequence 0 Digital Comparator Select (ADCSSDC0) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x054 Type RW, reset 0x0000.0000 31 30 29 28 27 26 S7DCSEL Type Reset 24 23 22 21 20 19 S5DCSEL 18 17 16 S4DCSEL RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 S3DCSEL Type Reset 25 S6DCSEL RW 0 RW 0 S2DCSEL RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:28 S7DCSEL RW 0x0 S1DCSEL RW 0 RW 0 RW 0 RW 0 S0DCSEL RW 0 RW 0 RW 0 RW 0 RW 0 Description Sample 7 Digital Comparator Select When the S7DCOP bit in the ADCSSOP0 register is set, this field indicates which digital comparator unit (and its associated set of control registers) receives the eighth sample from Sample Sequencer 0. Note: Values not listed are reserved. Value Description 27:24 S6DCSEL RW 0x0 0x0 Digital Comparator Unit 0 (ADCDCCMP0 and ADCDCCTL0) 0x1 Digital Comparator Unit 1 (ADCDCCMP1 and ADCDCCTL1) 0x2 Digital Comparator Unit 2 (ADCDCCMP2 and ADCDCCTL2) 0x3 Digital Comparator Unit 3 (ADCDCCMP3 and ADCDCCTL3) 0x4 Digital Comparator Unit 4 (ADCDCCMP4 and ADCDCCTL4) 0x5 Digital Comparator Unit 5 (ADCDCCMP5 and ADCDCCTL5) 0x6 Digital Comparator Unit 6 (ADCDCCMP6 and ADCDCCTL6) 0x7 Digital Comparator Unit 7 (ADCDCCMP7 and ADCDCCTL7) Sample 6 Digital Comparator Select This field has the same encodings as S7DCSEL but is used during the seventh sample. 23:20 S5DCSEL RW 0x0 Sample 5 Digital Comparator Select This field has the same encodings as S7DCSEL but is used during the sixth sample. 19:16 S4DCSEL RW 0x0 Sample 4 Digital Comparator Select This field has the same encodings as S7DCSEL but is used during the fifth sample. 15:12 S3DCSEL RW 0x0 Sample 3 Digital Comparator Select This field has the same encodings as S7DCSEL but is used during the fourth sample. June 18, 2014 1123 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 11:8 S2DCSEL RW 0x0 Description Sample 2 Digital Comparator Select This field has the same encodings as S7DCSEL but is used during the third sample. 7:4 S1DCSEL RW 0x0 Sample 1 Digital Comparator Select This field has the same encodings as S7DCSEL but is used during the second sample. 3:0 S0DCSEL RW 0x0 Sample 0 Digital Comparator Select This field has the same encodings as S7DCSEL but is used during the first sample. 1124 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 27: ADC Sample Sequence Extended Input Multiplexer Select 0 (ADCSSEMUX0), offset 0x058 This register, along with the ADCSSMUX0 register, defines the analog input configuration for each sample in a sequence executed with Sample Sequencer 0. If a bit in this register is set, the corresponding MUXn field in the ADCSSMUX0 register selects from AIN[19:16]. When a bit in this register is clear, the corresponding MUXn field selects from AIN[15:0]. This register is 32 bits wide and contains information for eight possible samples. Note that this register is not used when the differential channel designation is used (the Dn bit is set in the ADCSSCTL0 register) because the ADCSSMUX0 register can select all the available pairs. ADC Sample Sequence Extended Input Multiplexer Select 0 (ADCSSEMUX0) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x058 Type RW, reset 0x0000.0000 31 30 29 reserved Type Reset 27 EMUX7 26 25 reserved 24 23 EMUX6 22 21 reserved 20 19 EMUX5 18 17 reserved 16 EMUX4 RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 RW 0 RO 0 RO 0 RO 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 reserved Type Reset 28 RO 0 RO 0 EMUX3 RO 0 RW 0 reserved RO 0 RO 0 EMUX2 RO 0 RW 0 reserved RO 0 RO 0 EMUX1 RO 0 RW 0 reserved RO 0 RO 0 EMUX0 RO 0 RW 0 Bit/Field Name Type Reset Description 31:29 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 28 EMUX7 RW 0x0 8th Sample Input Select (Upper Bit) The EMUX7 field is used during the eighth sample of a sequence executed with the sample sequencer. Value Description 0 The eighth sample input is selected from AIN[15:0] using the ADCSSMUX0 register. For example, if the MUX7 field is 0x0, AIN0 is selected. 1 The eighth sample input is selected from AIN[19:16] using the ADCSSMUX0 register. For example, if the MUX7 field is 0x0, AIN16 is selected. 27:25 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 24 EMUX6 RW 0x0 7th Sample Input Select (Upper Bit) The EMUX6 field is used during the seventh sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX7. 23:21 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1125 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 20 EMUX5 RW 0x0 Description 6th Sample Input Select (Upper Bit) The EMUX5 field is used during the sixth sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX7. 19:17 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 16 EMUX4 RW 0x0 5th Sample Input Select (Upper Bit) The EMUX4 field is used during the fifth sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX7. 15:13 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 12 EMUX3 RW 0x0 4th Sample Input Select (Upper Bit) The EMUX3 field is used during the fourth sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX7. 11:9 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 EMUX2 RW 0x0 3rd Sample Input Select (Upper Bit) The EMUX2 field is used during the third sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX7. 7:5 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 EMUX1 RW 0x0 2th Sample Input Select (Upper Bit) The EMUX1 field is used during the second sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX7. 3:1 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 EMUX0 RW 0x0 1st Sample Input Select (Upper Bit) The EMUX0 field is used during the first sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX7. 1126 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 28: ADC Sample Sequence 0 Sample and Hold Time (ADCSSTSH0), offset 0x05C This register controls the sample period size for each sample of sequencer 0. Each sample and hold period select specifies the time allocated to the sample and hold circuit as shown by the encodings in Table 15-3 on page 1058. Note: If sampling the internal temperature sensor, the sample and hold width should be at least 16 ADC clocks (TSHn = 0x4). Table 15-8. Sample and Hold Width in ADC Clocks TSHn Encoding NSH 0x0 4 0x1 reserved 0x2 8 0x3 reserved 0x4 16 0x5 reserved 0x6 32 0x7 reserved 0x8 64 0x9 reserved 0xA 128 0xB reserved 0xC 256 0xD-0xF reserved ADC Sample Sequence 0 Sample and Hold Time (ADCSSTSH0) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x05C Type RW, reset 0x0000.0000 31 30 29 28 27 26 RW 0 25 24 23 22 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 TSH7 Type Reset 20 19 18 RW 0 RW 0 RW 0 RW 0 7 6 5 4 RW 0 RW 0 RW 0 RW 0 TSH6 TSH3 Type Reset 21 17 16 RW 0 RW 0 RW 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 TSH5 TSH2 TSH4 TSH1 Bit/Field Name Type Reset 31:28 TSH7 RW 0x0 TSH0 Description 8th Sample and Hold Period Select The TSH7 field is used during the eighth sample of a sequence executed with the sample sequencer. 27:24 TSH6 RW 0x0 7th Sample and Hold Period Select The TSH6 field is used during the seventh sample of a sequence executed with the sample sequencer. June 18, 2014 1127 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 23:20 TSH5 RW 0x0 Description 6th Sample and Hold Period Select The TSH5 field is used during the sixth sample of a sequence executed with the sample sequencer. 19:16 TSH4 RW 0x0 5th Sample and Hold Period Select The TSH4 field is used during the fifth sample of a sequence executed with the sample sequencer. 15:12 TSH3 RW 0x0 4th Sample and Hold Period Select The TSH3 field is used during the fourth sample of a sequence executed with the sample sequencer. 11:8 TSH2 RW 0x0 3rd Sample and Hold Period Select The TSH2 field is used during the third sample of a sequence executed with the sample sequencer. 7:4 TSH1 RW 0x0 2nd Sample and Hold Period Select The TSH1 field is used during the second sample of a sequence executed with the sample sequencer. 3:0 TSH0 RW 0x0 1st Sample and Hold Period Select The TSH0 field is used during the first sample of a sequence executed with the sample sequencer. 1128 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 29: ADC Sample Sequence Input Multiplexer Select 1 (ADCSSMUX1), offset 0x060 Register 30: ADC Sample Sequence Input Multiplexer Select 2 (ADCSSMUX2), offset 0x080 This register, along with the ADCSSEMUX1 or ADCSSEMUX2 register, defines the analog input configuration for each sample in a sequence executed with Sample Sequencer 1 or 2. If the corresponding EMUXn bit in the ADCSSEMUX1 or ADCSSEMUX2 register is set, the MUXn field in this register selects from AIN[19:16]. When the corresponding EMUXn bit is clear, the MUXn field selects from AIN[15:0]. These registers are 16 bits wide and contain information for four possible samples. See the ADCSSMUX0 register on page 1109 for detailed bit descriptions. The ADCSSMUX1 register affects Sample Sequencer 1 and the ADCSSMUX2 register affects Sample Sequencer 2. Note: Channels AIN[31:20] do not exist on this microcontroller. Configuring MUXn to be 0xC-0xF when the corresponding EMUXn bit is set results in undefined behavior. ADC Sample Sequence Input Multiplexer Select n (ADCSSMUXn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x060 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 15 14 RO 0 RO 0 RO 0 RO 0 13 12 11 10 MUX3 Type Reset RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 MUX2 RW 0 RW 0 RW 0 RW 0 MUX1 RW 0 RW 0 RW 0 RW 0 MUX0 RW 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15:12 MUX3 RW 0x0 4th Sample Input Select 11:8 MUX2 RW 0x0 3rd Sample Input Select 7:4 MUX1 RW 0x0 2nd Sample Input Select 3:0 MUX0 RW 0x0 1st Sample Input Select RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1129 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 31: ADC Sample Sequence Control 1 (ADCSSCTL1), offset 0x064 Register 32: ADC Sample Sequence Control 2 (ADCSSCTL2), offset 0x084 These registers contain the configuration information for each sample for a sequence executed with Sample Sequencer 1 or 2. When configuring a sample sequence, the END bit must be set for the final sample, whether it be after the first sample, fourth sample, or any sample in between. These registers are 16-bits wide and contain information for four possible samples. See the ADCSSCTL0 register on page 1111 for detailed bit descriptions. The ADCSSCTL1 register configures Sample Sequencer 1 and the ADCSSCTL2 register configures Sample Sequencer 2. ADC Sample Sequence Control n (ADCSSCTLn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x064 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 TS3 IE3 END3 D3 TS2 IE2 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 END2 D2 TS1 IE1 END1 D1 TS0 IE0 END0 D0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset Type Reset Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 TS3 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4th Sample Temp Sensor Select Value Description 14 IE3 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the fourth sample of the sample sequence. 1 The temperature sensor is read during the fourth sample of the sample sequence. 4th Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the fourth sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 1130 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 13 END3 RW 0 Description 4th Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The fourth sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 12 D3 RW 0 4th Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS3 bit is set. 11 TS2 RW 0 3rd Sample Temp Sensor Select Value Description 10 IE2 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the third sample of the sample sequence. 1 The temperature sensor is read during the third sample of the sample sequence. 3rd Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the third sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 9 END2 RW 0 3rd Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The third sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. June 18, 2014 1131 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 8 D2 RW 0 Description 3rd Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS2 bit is set. 7 TS1 RW 0 2nd Sample Temp Sensor Select Value Description 6 IE1 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the second sample of the sample sequence. 1 The temperature sensor is read during the second sample of the sample sequence. 2nd Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the second sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 5 END1 RW 0 2nd Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The second sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 4 D1 RW 0 2nd Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS1 bit is set. 1132 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 TS0 RW 0 Description 1st Sample Temp Sensor Select Value Description 2 IE0 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the first sample of the sample sequence. 1 The temperature sensor is read during the first sample of the sample sequence. 1st Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of the first sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 1 END0 RW 0 1st Sample is End of Sequence Value Description 0 Another sample in the sequence is the final sample. 1 The first sample is the last sample of the sequence. It is possible to end the sequence on any sample position. Software must set an ENDn bit somewhere within the sequence. Samples defined after the sample containing a set ENDn bit are not requested for conversion even though the fields may be non-zero. 0 D0 RW 0 1st Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS0 bit is set. June 18, 2014 1133 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 33: ADC Sample Sequence 1 Operation (ADCSSOP1), offset 0x070 Register 34: ADC Sample Sequence 2 Operation (ADCSSOP2), offset 0x090 This register determines whether the sample from the given conversion on Sample Sequence n is saved in the Sample Sequence n FIFO or sent to the digital comparator unit. The ADCSSOP1 register controls Sample Sequencer 1 and the ADCSSOP2 register controls Sample Sequencer 2. ADC Sample Sequence n Operation (ADCSSOPn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x070 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 reserved Type Reset reserved Type Reset RO 0 RO 0 S3DCOP RO 0 RW 0 reserved RO 0 RO 0 S2DCOP RO 0 Bit/Field Name Type Reset 31:13 reserved RO 0x0000.0 12 S3DCOP RW 0 RW 0 reserved RO 0 RO 0 S1DCOP RO 0 RW 0 reserved RO 0 RO 0 S0DCOP RO 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 3 Digital Comparator Operation Value Description 11:9 reserved RO 0x0 8 S2DCOP RW 0 0 The fourth sample is saved in Sample Sequence FIFOn. 1 The fourth sample is sent to the digital comparator unit specified by the S3DCSEL bit in the ADCSSDC0n register, and the value is not written to the FIFO. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 2 Digital Comparator Operation Same definition as S3DCOP but used during the third sample. 7:5 reserved RO 0x0 4 S1DCOP RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 1 Digital Comparator Operation Same definition as S3DCOP but used during the second sample. 3:1 reserved RO 0x0 0 S0DCOP RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 0 Digital Comparator Operation Same definition as S3DCOP but used during the first sample. 1134 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 35: ADC Sample Sequence 1 Digital Comparator Select (ADCSSDC1), offset 0x074 Register 36: ADC Sample Sequence 2 Digital Comparator Select (ADCSSDC2), offset 0x094 These registers determine which digital comparator receives the sample from the given conversion on Sample Sequence n if the corresponding SnDCOP bit in the ADCSSOPn register is set. The ADCSSDC1 register controls the selection for Sample Sequencer 1 and the ADCSSDC2 register controls the selection for Sample Sequencer 2. ADC Sample Sequence n Digital Comparator Select (ADCSSDCn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x074 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset S3DCSEL Type Reset S2DCSEL RW 0 RW 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15:12 S3DCSEL RW 0x0 S1DCSEL RW 0 S0DCSEL RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 3 Digital Comparator Select When the S3DCOP bit in the ADCSSOPn register is set, this field indicates which digital comparator unit (and its associated set of control registers) receives the eighth sample from Sample Sequencer n. Note: Values not listed are reserved. Value Description 11:8 S2DCSEL RW 0x0 0x0 Digital Comparator Unit 0 (ADCDCCMP0 and ADCCCTL0) 0x1 Digital Comparator Unit 1 (ADCDCCMP1 and ADCCCTL1) 0x2 Digital Comparator Unit 2 (ADCDCCMP2 and ADCCCTL2) 0x3 Digital Comparator Unit 3 (ADCDCCMP3 and ADCCCTL3) 0x4 Digital Comparator Unit 4 (ADCDCCMP4 and ADCCCTL4) 0x5 Digital Comparator Unit 5 (ADCDCCMP5 and ADCCCTL5) 0x6 Digital Comparator Unit 6 (ADCDCCMP6 and ADCCCTL6) 0x7 Digital Comparator Unit 7 (ADCDCCMP7 and ADCCCTL7) Sample 2 Digital Comparator Select This field has the same encodings as S3DCSEL but is used during the third sample. June 18, 2014 1135 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 7:4 S1DCSEL RW 0x0 Description Sample 1 Digital Comparator Select This field has the same encodings as S3DCSEL but is used during the second sample. 3:0 S0DCSEL RW 0x0 Sample 0 Digital Comparator Select This field has the same encodings as S3DCSEL but is used during the first sample. 1136 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 37: ADC Sample Sequence Extended Input Multiplexer Select 1 (ADCSSEMUX1), offset 0x078 Register 38: ADC Sample Sequence Extended Input Multiplexer Select 2 (ADCSSEMUX2), offset 0x098 This register, along with the ADCSSMUX1 or ADCSSMUX2 register, defines the analog input configuration for each sample in a sequence executed with either Sample Sequencer 1 or 2. If a bit in this register is set, the corresponding MUXn field in the ADCSSMUX1 or ADCSSMUX2 register selects from AIN[19:16]. When a bit in this register is clear, the corresponding MUXn field selects from AIN[15:0]. This register is 16 bits wide and contains information for four possible samples. The ADCSSEMUX1 register controls Sample Sequencer 1 and the ADCSSEMUX2 register controls Sample Sequencer 2. Note that this register is not used when the differential channel designation is used (the Dn bit is set in the ADCSSCTL1 or ADCSSCTL2 register) because the ADCSSMUX1 or ADCSSMUX2 register can select all the available pairs. ADC Sample Sequence Extended Input Multiplexer Select n (ADCSSEMUXn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x078 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 reserved Type Reset RO 0 15 RO 0 RO 0 14 13 reserved Type Reset RO 0 RO 0 RO 0 RO 0 12 11 EMUX3 RO 0 RW 0 RO 0 RO 0 10 9 reserved RO 0 RO 0 RO 0 RO 0 8 7 EMUX2 RO 0 Bit/Field Name Type Reset 31:13 reserved RO 0x0000 12 EMUX3 RW 0x0 RW 0 reserved RO 0 RO 0 EMUX1 RO 0 RW 0 reserved RO 0 RO 0 0 EMUX0 RO 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4th Sample Input Select (Upper Bit) The EMUX3 field is used during the fourth sample of a sequence executed with the sample sequencer. Value Description 11:9 reserved RO 0x0 0 The fourth sample input is selected from AIN[15:0] using the ADCSSMUX1 or ADCSSMUX2 register. For example, if the MUX3 field is 0x0, AIN0 is selected. 1 The fourth sample input is selected from AIN[19:16] using the ADCSSMUX1 or ADCSSMUX2 register. For example, if the MUX3 field is 0x0, AIN16 is selected. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1137 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 8 EMUX2 RW 0x0 Description 3rd Sample Input Select (Upper Bit) The EMUX2 field is used during the third sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX3. 7:5 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 4 EMUX1 RW 0x0 2th Sample Input Select (Upper Bit) The EMUX1 field is used during the second sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX3. 3:1 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 EMUX0 RW 0x0 1st Sample Input Select (Upper Bit) The EMUX0 field is used during the first sample of a sequence executed with the sample sequencer. This bit has the same description as EMUX3. 1138 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 39: ADC Sample Sequence 1 Sample and Hold Time (ADCSSTSH1), offset 0x07C Register 40: ADC Sample Sequence 2 Sample and Hold Time (ADCSSTSH2), offset 0x09C These registers control the sample period size for each sample step of sequencer 1 and sequencer 2. Each sample and hold period select specifies the time allocated to the sample and hold circuit as shown by the encodings in Table 15-3 on page 1058. Note: If sampling the internal temperature sensor, the sample and hold width should be at least 16 ADC clocks (TSHn = 0x4). Table 15-9. Sample and Hold Width in ADC Clocks TSHn Encoding NSH 0x0 4 0x1 reserved 0x2 8 0x3 reserved 0x4 16 0x5 reserved 0x6 32 0x7 reserved 0x8 64 0x9 reserved 0xA 128 0xB reserved 0xC 256 0xD-0xF reserved ADC Sample Sequence n Sample and Hold Time (ADCSSTSHn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x07C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 15 14 RO 0 RO 0 RO 0 RO 0 13 12 11 10 TSH3 Type Reset RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 TSH2 RW 0 RW 0 RW 0 RW 0 TSH1 RW 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 RW 0 RW 0 RW 0 TSH0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1139 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 15:12 TSH3 RW 0x0 Description 4th Sample and Hold Period Select The TSH3 field is used during the fourth sample of a sequence executed with the sample sequencer. 11:8 TSH2 RW 0x0 3rd Sample and Hold Period Select The TSH2 field is used during the third sample of a sequence executed with the sample sequencer. 7:4 TSH1 RW 0x0 2nd Sample and Hold Period Select The TSH1 field is used during the second sample of a sequence executed with the sample sequencer. 3:0 TSH0 RW 0x0 1st Sample and Hold Period Select The TSH0 field is used during the first sample of a sequence executed with the sample sequencer. 1140 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 41: ADC Sample Sequence Input Multiplexer Select 3 (ADCSSMUX3), offset 0x0A0 This register, along with the ADCSSEMUX3 register, defines the analog input configuration for the sample in a sequence executed with Sample Sequencer 3. If the EMUX0 bit in the ADCSSEMUX3 register is set, the MUX0 field in this register selects from AIN[19:16]. When the EMUX0 bit is clear, the MUX0 field selects from AIN[15:0]. This register is four bits wide and contains information for one possible sample. See the ADCSSMUX0 register on page 1109 for detailed bit descriptions. ADC Sample Sequence Input Multiplexer Select 3 (ADCSSMUX3) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x0A0 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 1 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 MUX0 RO 0 Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 MUX0 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1st Sample Input Select June 18, 2014 1141 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 42: ADC Sample Sequence Control 3 (ADCSSCTL3), offset 0x0A4 This register contains the configuration information for a sample executed with Sample Sequencer 3. This register is 4 bits wide and contains information for one possible sample. See the ADCSSCTL0 register on page 1111 for detailed bit descriptions. Note: When configuring a sample sequence in this register, the END0 bit must be set. ADC Sample Sequence Control 3 (ADCSSCTL3) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x0A4 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 TS0 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 TS0 IE0 END0 D0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1st Sample Temp Sensor Select Value Description 2 IE0 RW 0 0 The input pin specified by the ADCSSMUXn register is read during the first sample of the sample sequence. 1 The temperature sensor is read during the first sample of the sample sequence. Sample Interrupt Enable Value Description 0 The raw interrupt is not asserted to the interrupt controller. 1 The raw interrupt signal (INR0 bit) is asserted at the end of this sample's conversion. If the MASK0 bit in the ADCIM register is set, the interrupt is promoted to the interrupt controller. It is legal to have multiple samples within a sequence generate interrupts. 1 END0 RW 0 End of Sequence This bit must be set before initiating a single sample sequence. Value Description 0 Sampling and conversion continues. 1 This is the end of sequence. 1142 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 D0 RW 0 Description Sample Differential Input Select Value Description 0 The analog inputs are not differentially sampled. 1 The analog input is differentially sampled. The corresponding ADCSSMUXn nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". Because the temperature sensor does not have a differential option, this bit must not be set when the TS0 bit is set. June 18, 2014 1143 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 43: ADC Sample Sequence 3 Operation (ADCSSOP3), offset 0x0B0 This register determines whether the sample from the given conversion on Sample Sequence 3 is saved in the Sample Sequence 3 FIFO or sent to the digital comparator unit. ADC Sample Sequence 3 Operation (ADCSSOP3) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x0B0 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 S0DCOP RW 0 RO 0 S0DCOP RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 0 Digital Comparator Operation Value Description 0 The sample is saved in Sample Sequence FIFO3. 1 The sample is sent to the digital comparator unit specified by the S0DCSEL bit in the ADCSSDC03 register, and the value is not written to the FIFO. 1144 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 44: ADC Sample Sequence 3 Digital Comparator Select (ADCSSDC3), offset 0x0B4 This register determines which digital comparator receives the sample from the given conversion on Sample Sequence 3 if the corresponding SnDCOP bit in the ADCSSOP3 register is set. ADC Sample Sequence 3 Digital Comparator Select (ADCSSDC3) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x0B4 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 S0DCSEL RW 0x0 S0DCSEL RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Sample 0 Digital Comparator Select When the S0DCOP bit in the ADCSSOP3 register is set, this field indicates which digital comparator unit (and its associated set of control registers) receives the sample from Sample Sequencer 3. Note: Values not listed are reserved. Value Description 0x0 Digital Comparator Unit 0 (ADCDCCMP0 and ADCCCTL0) 0x1 Digital Comparator Unit 1 (ADCDCCMP1 and ADCCCTL1) 0x2 Digital Comparator Unit 2 (ADCDCCMP2 and ADCCCTL2) 0x3 Digital Comparator Unit 3 (ADCDCCMP3 and ADCCCTL3) 0x4 Digital Comparator Unit 4 (ADCDCCMP4 and ADCCCTL4) 0x5 Digital Comparator Unit 5 (ADCDCCMP5 and ADCCCTL5) 0x6 Digital Comparator Unit 6 (ADCDCCMP6 and ADCCCTL6) 0x7 Digital Comparator Unit 7 (ADCDCCMP7 and ADCCCTL7) June 18, 2014 1145 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 45: ADC Sample Sequence Extended Input Multiplexer Select 3 (ADCSSEMUX3), offset 0x0B8 This register, along with the ADCSSMUX3 register, defines the analog input configuration for the sample in a sequence executed with Sample Sequencer 3. If EMUX0 is set, the MUX0 field in the ADCSSMUX3 register selects from AIN[19:16]. When EMUX0 is clear, the MUX0 field selects from AIN[15:0]. This register is 1 bit wide and contains information for one possible sample. Note that this register is not used when the differential channel designation is used (the Dn bit is set in the ADCSSCTL3 register) because the ADCSSMUX3 register can select all the available pairs. ADC Sample Sequence Extended Input Multiplexer Select 3 (ADCSSEMUX3) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x0B8 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 EMUX0 RW 0x0 RO 0 EMUX0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1st Sample Input Select (Upper Bit) The EMUX0 field is used during the only sample of a sequence executed with the sample sequencer. Value Description 0 The sample input is selected from AIN[15:0] using the ADCSSMUX3 register. For example, if the MUX0 field is 0x0, AIN0 is selected. 1 The sample input is selected from AIN[19:16] using the ADCSSMUX3 register. For example, if the MUX0 field is 0x0, AIN16 is selected. 1146 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 46: ADC Sample Sequence 3 Sample and Hold Time (ADCSSTSH3), offset 0x0BC This register controls the sample period size for the sample in sequencer 3. The sample and hold period select specifies the time allocated to the sample and hold circuit as shown by the encodings in Table 15-3 on page 1058 Note: If sampling the internal temperature sensor, the sample and hold width should be at least 16 ADC clocks (TSHn = 0x4). Table 15-10. Sample and Hold Width in ADC Clocks TSHn Encoding NSH 0x0 4 0x1 reserved 0x2 8 0x3 reserved 0x4 16 0x5 reserved 0x6 32 0x7 reserved 0x8 64 0x9 reserved 0xA 128 0xB reserved 0xC 256 0xD-0xF reserved ADC Sample Sequence 3 Sample and Hold Time (ADCSSTSH3) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0x0BC Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset TSH0 Bit/Field Name Type Reset Description 31:4 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3:0 TSH0 RW 0x0 1st Sample and Hold Period Select The TSH0 field is used during the first sample of a sequence executed with the sample sequencer. June 18, 2014 1147 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 47: ADC Digital Comparator Reset Initial Conditions (ADCDCRIC), offset 0xD00 This register provides the ability to reset any of the digital comparator interrupt or trigger functions back to their initial conditions. Resetting these functions ensures that the data that is being used by the interrupt and trigger functions in the digital comparator unit is not stale. ADC Digital Comparator Reset Initial Conditions (ADCDCRIC) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0xD00 Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 DCTRIG7 DCTRIG6 DCTRIG5 DCTRIG4 DCTRIG3 DCTRIG2 DCTRIG1 DCTRIG0 RO 0 RO 0 RO 0 RO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 7 6 5 4 3 2 1 0 DCINT7 DCINT6 DCINT5 DCINT4 DCINT3 DCINT2 DCINT1 DCINT0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 Bit/Field Name Type Reset Description 31:24 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 23 DCTRIG7 WO 0 Digital Comparator Trigger 7 Value Description 0 No effect. 1 Resets the Digital Comparator 7 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. After setting this bit, software should wait until the bit clears before continuing. 22 DCTRIG6 WO 0 Digital Comparator Trigger 6 Value Description 0 No effect. 1 Resets the Digital Comparator 6 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 1148 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 21 DCTRIG5 WO 0 Description Digital Comparator Trigger 5 Value Description 0 No effect. 1 Resets the Digital Comparator 5 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 20 DCTRIG4 WO 0 Digital Comparator Trigger 4 Value Description 0 No effect. 1 Resets the Digital Comparator 4 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 19 DCTRIG3 WO 0 Digital Comparator Trigger 3 Value Description 0 No effect. 1 Resets the Digital Comparator 3 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 18 DCTRIG2 WO 0 Digital Comparator Trigger 2 Value Description 0 No effect. 1 Resets the Digital Comparator 2 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. June 18, 2014 1149 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 17 DCTRIG1 WO 0 Description Digital Comparator Trigger 1 Value Description 0 No effect. 1 Resets the Digital Comparator 1 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 16 DCTRIG0 WO 0 Digital Comparator Trigger 0 Value Description 0 No effect. 1 Resets the Digital Comparator 0 trigger unit to its initial conditions. When the trigger has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the trigger, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 15:8 reserved RO 0x00 7 DCINT7 WO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Digital Comparator Interrupt 7 Value Description 0 No effect. 1 Resets the Digital Comparator 7 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 6 DCINT6 WO 0 Digital Comparator Interrupt 6 Value Description 0 No effect. 1 Resets the Digital Comparator 6 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 1150 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 5 DCINT5 WO 0 Description Digital Comparator Interrupt 5 Value Description 0 No effect. 1 Resets the Digital Comparator 5 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 4 DCINT4 WO 0 Digital Comparator Interrupt 4 Value Description 0 No effect. 1 Resets the Digital Comparator 4 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 3 DCINT3 WO 0 Digital Comparator Interrupt 3 Value Description 0 No effect. 1 Resets the Digital Comparator 3 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 2 DCINT2 WO 0 Digital Comparator Interrupt 2 Value Description 0 No effect. 1 Resets the Digital Comparator 2 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. June 18, 2014 1151 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 1 DCINT1 WO 0 Description Digital Comparator Interrupt 1 Value Description 0 No effect. 1 Resets the Digital Comparator 1 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 0 DCINT0 WO 0 Digital Comparator Interrupt 0 Value Description 0 No effect. 1 Resets the Digital Comparator 0 interrupt unit to its initial conditions. When the interrupt has been cleared, this bit is automatically cleared. Because the digital comparators use the current and previous ADC conversion values to determine when to assert the interrupt, it is important to reset the digital comparator to initial conditions when starting a new sequence so that stale data is not used. 1152 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 48: ADC Digital Comparator Control 0 (ADCDCCTL0), offset 0xE00 Register 49: ADC Digital Comparator Control 1 (ADCDCCTL1), offset 0xE04 Register 50: ADC Digital Comparator Control 2 (ADCDCCTL2), offset 0xE08 Register 51: ADC Digital Comparator Control 3 (ADCDCCTL3), offset 0xE0C Register 52: ADC Digital Comparator Control 4 (ADCDCCTL4), offset 0xE10 Register 53: ADC Digital Comparator Control 5 (ADCDCCTL5), offset 0xE14 Register 54: ADC Digital Comparator Control 6 (ADCDCCTL6), offset 0xE18 Register 55: ADC Digital Comparator Control 7 (ADCDCCTL7), offset 0xE1C This register provides the comparison encodings that generate an interrupt and/or PWM trigger. See “Interrupt/ADC-Trigger Selector” on page 1675 for more information on using the ADC digital comparators to trigger a PWM generator. ADC Digital Comparator Control n (ADCDCCTLn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0xE00 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RO 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 RO 0 CTE RO 0 RW 0 CTC RW 0 CTM Bit/Field Name Type Reset 31:13 reserved RO 0x0000.0 12 CTE RW 0 reserved RO 0 CIE RO 0 RW 0 CIC RW 0 CIM RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Comparison Trigger Enable Value Description 0 Disables the trigger function state machine. ADC conversion data is ignored by the trigger function. 1 Enables the trigger function state machine. The ADC conversion data is used to determine if a trigger should be generated according to the programming of the CTC and CTM fields. June 18, 2014 1153 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset 11:10 CTC RW 0x0 Description Comparison Trigger Condition This field specifies the operational region in which a trigger is generated when the ADC conversion data is compared against the values of COMP0 and COMP1. The COMP0 and COMP1 fields are defined in the ADCDCCMPx registers. Value Description 0x0 Low Band ADC Data < COMP0 ≤ COMP1 0x1 Mid Band COMP0 < ADC Data ≤ COMP1 0x2 reserved 0x3 High Band COMP0 ≤ COMP1 ≤ ADC Data 9:8 CTM RW 0x0 Comparison Trigger Mode This field specifies the mode by which the trigger comparison is made. Value Description 0x0 Always This mode generates a trigger every time the ADC conversion data falls within the selected operational region. 0x1 Once This mode generates a trigger the first time that the ADC conversion data enters the selected operational region. 0x2 Hysteresis Always This mode generates a trigger when the ADC conversion data falls within the selected operational region and continues to generate the trigger until the hysteresis condition is cleared by entering the opposite operational region. Note that the hysteresis modes are only defined for CTC encodings of 0x0 and 0x3. 0x3 Hysteresis Once This mode generates a trigger the first time that the ADC conversion data falls within the selected operational region. No additional triggers are generated until the hysteresis condition is cleared by entering the opposite operational region. Note that the hysteresis modes are only defined for CTC encodings of 0x0 and 0x3. 7:5 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1154 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 CIE RW 0 Description Comparison Interrupt Enable Value Description 3:2 CIC RW 0x0 0 Disables the comparison interrupt. ADC conversion data has no effect on interrupt generation. 1 Enables the comparison interrupt. The ADC conversion data is used to determine if an interrupt should be generated according to the programming of the CIC and CIM fields. Comparison Interrupt Condition This field specifies the operational region in which an interrupt is generated when the ADC conversion data is compared against the values of COMP0 and COMP1. The COMP0 and COMP1 fields are defined in the ADCDCCMPx registers. Value Description 0x0 Low Band ADC Data < COMP0 ≤ COMP1 0x1 Mid Band COMP0 ≤ ADC Data < COMP1 0x2 reserved 0x3 High Band COMP0 < COMP1 ≤ ADC Data 1:0 CIM RW 0x0 Comparison Interrupt Mode This field specifies the mode by which the interrupt comparison is made. Value Description 0x0 Always This mode generates an interrupt every time the ADC conversion data falls within the selected operational region. 0x1 Once This mode generates an interrupt the first time that the ADC conversion data enters the selected operational region. 0x2 Hysteresis Always This mode generates an interrupt when the ADC conversion data falls within the selected operational region and continues to generate the interrupt until the hysteresis condition is cleared by entering the opposite operational region. Note that the hysteresis modes are only defined for CTC encodings of 0x0 and 0x3. 0x3 Hysteresis Once This mode generates an interrupt the first time that the ADC conversion data falls within the selected operational region. No additional interrupts are generated until the hysteresis condition is cleared by entering the opposite operational region. Note that the hysteresis modes are only defined for CTC encodings of 0x0 and 0x3. June 18, 2014 1155 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 56: ADC Digital Comparator Range 0 (ADCDCCMP0), offset 0xE40 Register 57: ADC Digital Comparator Range 1 (ADCDCCMP1), offset 0xE44 Register 58: ADC Digital Comparator Range 2 (ADCDCCMP2), offset 0xE48 Register 59: ADC Digital Comparator Range 3 (ADCDCCMP3), offset 0xE4C Register 60: ADC Digital Comparator Range 4 (ADCDCCMP4), offset 0xE50 Register 61: ADC Digital Comparator Range 5 (ADCDCCMP5), offset 0xE54 Register 62: ADC Digital Comparator Range 6 (ADCDCCMP6), offset 0xE58 Register 63: ADC Digital Comparator Range 7 (ADCDCCMP7), offset 0xE5C This register defines the comparison values that are used to determine if the ADC conversion data falls in the appropriate operating region. Note: The value in the COMP1 field must be greater than or equal to the value in the COMP0 field or unexpected results can occur. ADC Digital Comparator Range n (ADCDCCMPn) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0xE40 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 reserved Type Reset 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset 21 COMP1 RO 0 RO 0 COMP0 RO 0 RO 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:28 reserved RO 0x0 27:16 COMP1 RW 0x000 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Compare 1 The value in this field is compared against the ADC conversion data. The result of the comparison is used to determine if the data lies within the high-band region. Note that the value of COMP1 must be greater than or equal to the value of COMP0. 15:12 reserved RO 0x0 11:0 COMP0 RW 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Compare 0 The value in this field is compared against the ADC conversion data. The result of the comparison is used to determine if the data lies within the low-band region. 1156 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 64: ADC Peripheral Properties (ADCPP), offset 0xFC0 The ADCPP register provides information regarding the properties of the ADC module. ADC Peripheral Properties (ADCPP) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0xFC0 Type RO, reset 0x01B0.2147 31 30 29 28 RO 0 RO 0 RO 0 15 14 13 RO 0 RO 0 RO 1 27 26 25 APSHT TS RO 0 RO 0 RO 0 RO 0 RO 1 12 11 10 9 RO 0 RO 0 RO 0 RO 0 reserved Type Reset 24 23 22 21 RO 1 RO 0 RO 1 8 7 6 RO 1 RO 0 RO 1 DC Type Reset 20 19 18 17 RO 1 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 1 RO 1 RO 1 RSL 16 TYPE CH MCR Bit/Field Name Type Reset Description 31:25 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 24 APSHT RO 0x1 Application-Programmable Sample-and-Hold Time This bit indicates the ADC has the capability of allowing the application to adjust the sample and hold window period. 23 TS RO 0x1 Temperature Sensor Value Description 0 The ADC module does not have a temperature sensor. 1 The ADC module has a temperature sensor. This field provides the similar information as the legacy DC1 register TEMPSNS bit. 22:18 RSL RO 0xC Resolution This field specifies the maximum number of binary bits used to represent the converted sample. The field is encoded as a binary value, in the range of 0 to 32 bits. 17:16 TYPE RO 0x0 ADC Architecture Value Description 0x0 SAR 0x1 - 0x3 Reserved 15:10 DC RO 0x8 Digital Comparator Count This field specifies the number of ADC digital comparators available to the converter. The field is encoded as a binary value, in the range of 0 to 63. This field provides similar information to the legacy DC9 register ADCnDCn bits. June 18, 2014 1157 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Bit/Field Name Type Reset Description 9:4 CH RO 0x14 ADC Channel Count This field specifies the number of ADC input channels available to the converter. This field is encoded as a binary value, in the range of 0 to 63. This field provides similar information to the legacy DC3 and DC8 register ADCnAINn bits. 3:0 MCR RO 0x7 Maximum Conversion Rate This field specifies the maximum value that may be programmed into the ADCPC register's CR field. Value Description 0x0-0x6 Reserved 0x7 Full conversion rate (FCONV) as defined by TADC and NSH. 0x8 - 0xF Reserved 1158 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 65: ADC Peripheral Configuration (ADCPC), offset 0xFC4 The ADCPC register provides information regarding the configuration of the peripheral. ADC Peripheral Configuration (ADCPC) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0xFC4 Type RW, reset 0x0000.0007 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 1 RW 1 RW 1 reserved Type Reset reserved Type Reset Bit/Field Name Type 31:4 reserved RO 3:0 MCR RW Reset MCR Description 0x0000.0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x7 Conversion Rate This field specifies the relative sample rate of the ADC and is used in run, sleep, and deep-sleep modes. It allows the application to reduce the rate at which conversions are generated relative to the maximum conversion rate. Value Description 0x0 Reserved 0x1 Eighth conversion rate. After a conversion completes, the logic pauses for 112 TADC periods before starting the next conversion. 0x2 Reserved 0x3 Quarter conversion rate. After a conversion completes, the logic pauses for 48 TADC periods before starting the next conversion. 0x4 Reserved 0x5 Half conversion rate. After a conversion completes, the logic pauses for 16 TADC periods before starting the next conversion. 0x6 Reserved 0x7 Full conversion rate (FCONV) as defined by TADC and NSH. 0x8 - 0xF Reserved June 18, 2014 1159 Texas Instruments-Production Data Analog-to-Digital Converter (ADC) Register 66: ADC Clock Configuration (ADCCC), offset 0xFC8 The ADCCC register controls the clock source for the ADC module. ADC Clock Configuration (ADCCC) ADC0 base: 0x4003.8000 ADC1 base: 0x4003.9000 Offset 0xFC8 Type RW, reset 0x0000.0001 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 1 reserved Type Reset reserved Type Reset RO 0 CLKDIV Bit/Field Name Type Reset 31:10 reserved RO 0x0000.00 9:4 CLKDIV RW 0x0 CS Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PLL VCO Clock Divisor Value Description 3:0 CS RW 0x1 0x0 /1 0x1 /2 0x2 /3 0xN /(N + 1) ADC Clock Source Value Description 0x0 PLL VCO divided by CLKDIV. 0x1 Alternate clock source as defined by ALTCLKCFG register in System Control Module. 0x2 MOSC 0x2 - 0xF Reserved 1160 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 16 Universal Asynchronous Receivers/Transmitters (UARTs) The TM4C1294NCPDT controller includes eight Universal Asynchronous Receiver/Transmitter (UART) with the following features: ■ Programmable baud-rate generator allowing speeds up to 7.5 Mbps for regular speed (divide by 16) and 15 Mbps for high speed (divide by 8) ■ Separate 16x8 transmit (TX) and receive (RX) FIFOs to reduce CPU interrupt service loading ■ Programmable FIFO length, including 1-byte deep operation providing conventional double-buffered interface ■ FIFO trigger levels of 1/8, 1/4, 1/2, 3/4, and 7/8 ■ Standard asynchronous communication bits for start, stop, and parity ■ Line-break generation and detection ■ Fully programmable serial interface characteristics – 5, 6, 7, or 8 data bits – Even, odd, stick, or no-parity bit generation/detection – 1 or 2 stop bit generation ■ IrDA serial-IR (SIR) encoder/decoder providing – Programmable use of IrDA Serial Infrared (SIR) or UART input/output – Support of IrDA SIR encoder/decoder functions for data rates up to 115.2 Kbps half-duplex – Support of normal 3/16 and low-power (1.41-2.23 μs) bit durations – Programmable internal clock generator enabling division of reference clock by 1 to 256 for low-power mode bit duration ■ Support for communication with ISO 7816 smart cards ■ Modem functionality available on the following UARTs: – UART0 (modem flow control and modem status) – UART1 (modem flow control and modem status) – UART2 (modem flow control) – UART3 (modem flow control) – UART4 (modem flow control) ■ EIA-485 9-bit support June 18, 2014 1161 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) ■ Standard FIFO-level and End-of-Transmission interrupts ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for transmit and receive – Receive single request asserted when data is in the FIFO; burst request asserted at programmed FIFO level – Transmit single request asserted when there is space in the FIFO; burst request asserted at programmed FIFO level ■ Global Alternate Clock (ALTCLK) resource or System Clock (SYSCLK) can be used to generate baud clock 16.1 Block Diagram Figure 16-1. UART Module Block Diagram PIOSC Clock Control UARTCC UARTCTL System Clock DMA Request Baud Clock DMA Control UARTDMACTL Interrupt Interrupt Control TxFIFO 16 x 8 UARTIFLS UARTIM UARTMIS UARTRIS UARTICR Identification Registers . . . UARTPCellID0 Transmitter (with SIR Transmit Encoder) UARTPCellID1 UnTx Baud Rate Generator UARTPCellID2 UARTPCellID3 UARTDR UARTPeriphID0 UARTIBRD UARTFBRD Receiver (with SIR Receive Decoder) Control/Status UARTPeriphID1 UnRx UARTRSR/ECR UARTPeriphID2 UARTFR UARTPeriphID3 RxFIFO 16 x 8 UARTLCRH UARTPeriphID4 UARTCTL UARTPeriphID5 UARTILPR UART9BITADDR UARTPeriphID6 . . . UART9BITAMASK UARTPeriphID7 16.2 UARTPP Signal Description The following table lists the external signals of the UART module and describes the function of each. The UART signals are alternate functions for some GPIO signals and default to be GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible GPIO pin 1162 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller placements for these UART signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the UART function. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the UART signal to the specified GPIO port pin. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Table 16-1. UART Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description U0CTS 30 74 121 PH1 (1) PM4 (1) PB4 (1) I TTL UART module 0 Clear To Send modem flow control input signal. U0DCD 31 73 104 PH2 (1) PM5 (1) PP3 (2) I TTL UART module 0 Data Carrier Detect modem status input signal. U0DSR 32 72 105 PH3 (1) PM6 (1) PP4 (2) I TTL UART module 0 Data Set Ready modem output control line. U0DTR 103 PP2 (1) O TTL UART module 0 Data Terminal Ready modem status input signal. U0RI 60 71 PK7 (1) PM7 (1) I TTL UART module 0 Ring Indicator modem status input signal. U0RTS 29 120 PH0 (1) PB5 (1) O TTL UART module 0 Request to Send modem flow control output signal. U0Rx 33 PA0 (1) I TTL UART module 0 receive. U0Tx 34 PA1 (1) O TTL UART module 0 transmit. U1CTS 104 108 PP3 (1) PN1 (1) I TTL UART module 1 Clear To Send modem flow control input signal. U1DCD 13 109 PE2 (1) PN2 (1) I TTL UART module 1 Data Carrier Detect modem status input signal. U1DSR 14 110 PE1 (1) PN3 (1) I TTL UART module 1 Data Set Ready modem output control line. U1DTR 12 111 PE3 (1) PN4 (1) O TTL UART module 1 Data Terminal Ready modem status input signal. U1RI 112 123 PN5 (1) PE4 (1) I TTL UART module 1 Ring Indicator modem status input signal. U1RTS 15 107 PE0 (1) PN0 (1) O TTL UART module 1 Request to Send modem flow control output line. U1Rx 95 102 PB0 (1) PQ4 (1) I TTL UART module 1 receive. U1Tx 96 PB1 (1) O TTL UART module 1 transmit. U2CTS 110 128 PN3 (2) PD7 (1) I TTL UART module 2 Clear To Send modem flow control input signal. U2RTS 109 127 PN2 (2) PD6 (1) O TTL UART module 2 Request to Send modem flow control output line. U2Rx 40 125 PA6 (1) PD4 (1) I TTL UART module 2 receive. U2Tx 41 126 PA7 (1) PD5 (1) O TTL UART module 2 transmit. U3CTS 106 112 PP5 (1) PN5 (2) I TTL UART module 3 Clear To Send modem flow control input signal. June 18, 2014 1163 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Table 16-1. UART Signals (128TQFP) (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description U3RTS 105 111 PP4 (1) PN4 (2) O TTL UART module 3 Request to Send modem flow control output line. U3Rx 37 116 PA4 (1) PJ0 (1) I TTL UART module 3 receive. U3Tx 38 117 PA5 (1) PJ1 (1) O TTL UART module 3 transmit. U4CTS 21 PK3 (1) I TTL UART module 4 Clear To Send modem flow control input signal. U4RTS 20 PK2 (1) O TTL UART module 4 Request to Send modem flow control output line. U4Rx 18 35 PK0 (1) PA2 (1) I TTL UART module 4 receive. U4Tx 19 36 PK1 (1) PA3 (1) O TTL UART module 4 transmit. U5Rx 23 PC6 (1) I TTL UART module 5 receive. U5Tx 22 PC7 (1) O TTL UART module 5 transmit. 16.3 U6Rx 118 PP0 (1) I TTL UART module 6 receive. U6Tx 119 PP1 (1) O TTL UART module 6 transmit. U7Rx 25 PC4 (1) I TTL UART module 7 receive. U7Tx 24 PC5 (1) O TTL UART module 7 transmit. Functional Description Each TM4C1294NCPDT UART performs the functions of parallel-to-serial and serial-to-parallel conversions. It is similar in functionality to a 16C550 UART, but is not register compatible. The UART is configured for transmit and/or receive via the TXE and RXE bits of the UART Control (UARTCTL) register (see page 1188). Transmit and receive are both enabled out of reset. Before any control registers are programmed, the UART must be disabled by clearing the UARTEN bit in UARTCTL. If the UART is disabled during a TX or RX operation, the current transaction is completed prior to the UART stopping. The UART module also includes a serial IR (SIR) encoder/decoder block that can be connected to an infrared transceiver to implement an IrDA SIR physical layer. The SIR function is programmed using the UARTCTL register. 16.3.1 Transmit/Receive Logic The transmit logic performs parallel-to-serial conversion on the data read from the transmit FIFO. The control logic outputs the serial bit stream beginning with a start bit and followed by the data bits (LSB first), parity bit, and the stop bits according to the programmed configuration in the control registers. See Figure 16-2 on page 1165 for details. The receive logic performs serial-to-parallel conversion on the received bit stream after a valid start pulse has been detected. Overrun, parity, frame error checking, and line-break detection are also performed, and their status accompanies the data that is written to the receive FIFO. 1164 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 16-2. UART Character Frame UnTX LSB 1 5-8 data bits 0 n Parity bit if enabled Start 16.3.2 1-2 stop bits MSB Baud-Rate Generation The baud-rate divisor is a 22-bit number consisting of a 16-bit integer and a 6-bit fractional part. The number formed by these two values is used by the baud-rate generator to determine the bit period. Having a fractional baud-rate divisor allows the UART to generate all the standard baud rates. The 16-bit integer is loaded through the UART Integer Baud-Rate Divisor (UARTIBRD) register (see page 1184) and the 6-bit fractional part is loaded with the UART Fractional Baud-Rate Divisor (UARTFBRD) register (see page 1185). The baud-rate divisor (BRD) has the following relationship to the system clock (where BRDI is the integer part of the BRD and BRDF is the fractional part, separated by a decimal place.) BRD = BRDI + BRDF = UARTSysClk / (ClkDiv * Baud Rate) where UARTSysClk is the system clock connected to the UART, and ClkDiv is either 16 (if HSE in UARTCTL is clear) or 8 (if HSE is set). By default, this will be the main system clock described in “Clock Control” on page 230. Alternatively, the UART may be clocked from the internal precision oscillator (PIOSC), independent of the system clock selection. This will allow the UART clock to be programmed independently of the system clock PLL settings. See the UARTCC register for more details. The 6-bit fractional number (that is to be loaded into the DIVFRAC bit field in the UARTFBRD register) can be calculated by taking the fractional part of the baud-rate divisor, multiplying it by 64, and adding 0.5 to account for rounding errors: UARTFBRD[DIVFRAC] = integer(BRDF * 64 + 0.5) The UART generates an internal baud-rate reference clock at 8x or 16x the baud-rate (referred to as Baud8 and Baud16, depending on the setting of the HSE bit (bit 5) in UARTCTL). This reference clock is divided by 8 or 16 to generate the transmit clock, and is used for error detection during receive operations. Note that the state of the HSE bit has no effect on clock generation in ISO 7816 smart card mode (when the SMART bit in the UARTCTL register is set). Along with the UART Line Control, High Byte (UARTLCRH) register (see page 1186), the UARTIBRD and UARTFBRD registers form an internal 30-bit register. This internal register is only updated when a write operation to UARTLCRH is performed, so any changes to the baud-rate divisor must be followed by a write to the UARTLCRH register for the changes to take effect. To update the baud-rate registers, there are four possible sequences: ■ UARTIBRD write, UARTFBRD write, and UARTLCRH write ■ UARTFBRD write, UARTIBRD write, and UARTLCRH write ■ UARTIBRD write and UARTLCRH write ■ UARTFBRD write and UARTLCRH write June 18, 2014 1165 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) 16.3.3 Data Transmission Data received or transmitted is stored in two 16-byte FIFOs, though the receive FIFO has an extra four bits per character for status information. For transmission, data is written into the transmit FIFO. If the UART is enabled, it causes a data frame to start transmitting with the parameters indicated in the UARTLCRH register. Data continues to be transmitted until there is no data left in the transmit FIFO. The BUSY bit in the UART Flag (UARTFR) register (see page 1180) is asserted as soon as data is written to the transmit FIFO (that is, if the FIFO is non-empty) and remains asserted while data is being transmitted. The BUSY bit is negated only when the transmit FIFO is empty, and the last character has been transmitted from the shift register, including the stop bits. The UART can indicate that it is busy even though the UART may no longer be enabled. When the receiver is idle (the UnRx signal is continuously 1), and the data input goes Low (a start bit has been received), the receive counter begins running and data is sampled on the eighth cycle of Baud16 or fourth cycle of Baud8 depending on the setting of the HSE bit (bit 5) in UARTCTL (described in “Transmit/Receive Logic” on page 1164). The start bit is valid and recognized if the UnRx signal is still low on the eighth cycle of Baud16 (HSE clear) or the fourth cycle of Baud 8 (HSE set), otherwise it is ignored. After a valid start bit is detected, successive data bits are sampled on every 16th cycle of Baud16 or 8th cycle of Baud8 (that is, one bit period later) according to the programmed length of the data characters and value of the HSE bit in UARTCTL. The parity bit is then checked if parity mode is enabled. Data length and parity are defined in the UARTLCRH register. Lastly, a valid stop bit is confirmed if the UnRx signal is High, otherwise a framing error has occurred. When a full word is received, the data is stored in the receive FIFO along with any error bits associated with that word. 16.3.4 Serial IR (SIR) The UART peripheral includes an IrDA serial-IR (SIR) encoder/decoder block. The IrDA SIR block provides functionality that converts between an asynchronous UART data stream and a half-duplex serial SIR interface. No analog processing is performed on-chip. The role of the SIR block is to provide a digital encoded output and decoded input to the UART. When enabled, the SIR block uses the UnTx and UnRx pins for the SIR protocol. These signals should be connected to an infrared transceiver to implement an IrDA SIR physical layer link. The SIR block can receive and transmit, but it is only half-duplex so it cannot do both at the same time. Transmission must be stopped before data can be received. The IrDA SIR physical layer specifies a minimum 10-ms delay between transmission and reception. The SIR block has two modes of operation: ■ In normal IrDA mode, a zero logic level is transmitted as a high pulse of 3/16th duration of the selected baud rate bit period on the output pin, while logic one levels are transmitted as a static LOW signal. These levels control the driver of an infrared transmitter, sending a pulse of light for each zero. On the reception side, the incoming light pulses energize the photo transistor base of the receiver, pulling its output LOW and driving the UART input pin LOW. ■ In low-power IrDA mode, the width of the transmitted infrared pulse is set to three times the period of the internally generated IrLPBaud16 signal (1.63 µs, assuming a nominal 1.8432 MHz frequency) by changing the appropriate bit in the UARTCTL register (see page 1188). Whether the device is in normal or low-power IrDA mode, a start bit is deemed valid if the decoder is still Low, one period of IrLPBaud16 after the Low was first detected. This enables a normal-mode UART to receive data from a low-power mode UART that can transmit pulses as small as 1.41 µs. Thus, for both low-power and normal mode operation, the ILPDVSR field in the UARTILPR register must be programmed such that 1.42 MHz < FIrLPBaud16 < 2.12 MHz, resulting in a low-power pulse 1166 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller duration of 1.41–2.11 μs (three times the period of IrLPBaud16). The minimum frequency of IrLPBaud16 ensures that pulses less than one period of IrLPBaud16 are rejected, but pulses greater than 1.4 μs are accepted as valid pulses. Figure 16-3 on page 1167 shows the UART transmit and receive signals, with and without IrDA modulation. Figure 16-3. IrDA Data Modulation Data bits Start bit UnTx 1 0 0 0 1 Stop bit 0 0 1 1 1 UnTx with IrDA 3 16 Bit period Bit period UnRx with IrDA UnRx 0 1 0 Start 1 0 0 1 1 Data bits 0 1 Stop In both normal and low-power IrDA modes: ■ During transmission, the UART data bit is used as the base for encoding ■ During reception, the decoded bits are transferred to the UART receive logic The IrDA SIR physical layer specifies a half-duplex communication link, with a minimum 10-ms delay between transmission and reception. This delay must be generated by software because it is not automatically supported by the UART. The delay is required because the infrared receiver electronics might become biased or even saturated from the optical power coupled from the adjacent transmitter LED. This delay is known as latency or receiver setup time. 16.3.5 ISO 7816 Support The UART offers basic support to allow communication with an ISO 7816 smartcard. When bit 3 (SMART) of the UARTCTL register is set, the UnTx signal is used as a bit clock, and the UnRx signal is used as the half-duplex communication line connected to the smartcard. A GPIO signal can be used to generate the reset signal to the smartcard. The remaining smartcard signals should be provided by the system design. The maximum clock rate in this mode is system clock / 16. When using ISO 7816 mode, the UARTLCRH register must be set to transmit 8-bit words (WLEN bits 6:5 configured to 0x3) with EVEN parity (PEN set and EPS set). In this mode, the UART automatically uses 2 stop bits, and the STP2 bit of the UARTLCRH register is ignored. If a parity error is detected during transmission, UnRx is pulled Low during the second stop bit. In this case, the UART aborts the transmission, flushes the transmit FIFO and discards any data it contains, and raises a parity error interrupt, allowing software to detect the problem and initiate retransmission of the affected data. Note that the UART does not support automatic retransmission in this case. June 18, 2014 1167 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) 16.3.6 Modem Handshake Support This section describes how to configure and use the modem flow control and status signals for a UART when connected as a DTE (data terminal equipment) or as a DCE (data communications equipment). In general, a modem is a DCE and a computing device that connects to a modem is the DTE. 16.3.6.1 Signaling The status signals provided by a UART differ based on whether the UART is used as a DTE or DCE. When used as a DTE, the modem flow control and status signals are defined as: ■ UnCTS is Clear To Send ■ UnDSR is Data Set Ready ■ UnDCD is Data Carrier Detect ■ UnRI is Ring Indicator ■ UnRTS is Request To Send ■ UnDTR is Data Terminal Ready When used as a DCE, the modem flow control and status signals are defined as: ■ UnCTS is Request To Send ■ UnDSR is Data Terminal Ready ■ UnRTS is Clear To Send ■ UnDTR is Data Set Ready Note that the support for DCE functions Data Carrier Detect and Ring Indicator are not provided. If these signals are required, their function can be emulated by using a general-purpose I/O signal and providing software support. 16.3.6.2 Flow Control Flow control can be accomplished by either hardware or software. The following sections describe the different methods. Hardware Flow Control (RTS/CTS) Hardware flow control between two devices is accomplished by connecting the UnRTS output to the Clear-To-Send input on the receiving device, and connecting the Request-To-Send output on the receiving device to the UnCTS input. The UnCTS input controls the transmitter. The transmitter may only transmit data when the UnCTS input is asserted. The UnRTS output signal indicates the state of the receive FIFO. UnCTS remains asserted until the preprogrammed watermark level is reached, indicating that the Receive FIFO has no space to store additional characters. The UARTCTL register bits 15 (CTSEN) and 14 (RTSEN) specify the flow control mode as shown in Table 16-2 on page 1169. 1168 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 16-2. Flow Control Mode Description CTSEN RTSEN 1 1 RTS and CTS flow control enabled 1 0 Only CTS flow control enabled 0 1 Only RTS flow control enabled 0 0 Both RTS and CTS flow control disabled Note that when RTSEN is 1, software cannot modify the UnRTS output value through the UARTCTL register Request to Send (RTS) bit, and the status of the RTS bit should be ignored. Software Flow Control (Modem Status Interrupts) Software flow control between two devices is accomplished by using interrupts to indicate the status of the UART. Interrupts may be generated for the UnDSR, UnDCD, UnCTS, and UnRI signals using bits 3:0 of the UARTIM register, respectively. The raw and masked interrupt status may be checked using the UARTRIS and UARTMIS register. These interrupts may be cleared using the UARTICR register. 16.3.7 9-Bit UART Mode The UART provides a 9-bit mode that is enabled with the 9BITEN bit in the UART9BITADDR register. This feature is useful in a multi-drop configuration of the UART where a single master connected to multiple slaves can communicate with a particular slave through its address or set of addresses along with a qualifier for an address byte. All the slaves check for the address qualifier in the place of the parity bit and, if set, then compare the byte received with the preprogrammed address. If the address matches, then it receives or sends further data. If the address does not match, it drops the address byte and any subsequent data bytes. If the UART is in 9-bit mode, then the receiver operates with no parity mode. The address can be predefined to match with the received byte and it can be configured with the UART9BITADDR register. The matching can be extended to a set of addresses using the address mask in the UART9BITAMASK register. By default, the UART9BITAMASK is 0xFF, meaning that only the specified address is matched. When not finding a match, the rest of the data bytes with the 9th bit cleared are dropped. If a match is found, then an interrupt is generated to the NVIC for further action. The subsequent data bytes with the cleared 9th bit are stored in the FIFO. Software can mask this interrupt in case μDMA and/or FIFO operations are enabled for this instance and processor intervention is not required. All the send transactions with 9-bit mode are data bytes and the 9th bit is cleared. Software can override the 9th bit to be set (to indicate address) by overriding the parity settings to sticky parity with odd parity enabled for a particular byte. To match the transmission time with correct parity settings, the address byte can be transmitted as a single then a burst transfer. The Transmit FIFO does not hold the address/data bit, hence software should take care of enabling the address bit appropriately. 16.3.8 FIFO Operation The UART has two 16x8 FIFOs; one for transmit and one for receive. Both FIFOs are accessed via the UART Data (UARTDR) register (see page 1175). Read operations of the UARTDR register return a 12-bit value consisting of 8 data bits and 4 error flags while write operations place 8-bit data in the transmit FIFO. Out of reset, both FIFOs are disabled and act as 1-byte-deep holding registers. The FIFOs are enabled by setting the FEN bit in UARTLCRH (page 1186). FIFO status can be monitored via the UART Flag (UARTFR) register (see page 1180) and the UART Receive Status (UARTRSR) register. Hardware monitors empty, full and overrun conditions. The June 18, 2014 1169 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) UARTFR register contains empty and full flags (TXFE, TXFF, RXFE, and RXFF bits), and the UARTRSR register shows overrun status via the OE bit. If the FIFOs are disabled, the empty and full flags are set according to the status of the 1-byte-deep holding registers. The trigger points at which the FIFOs generate interrupts is controlled via the UART Interrupt FIFO Level Select (UARTIFLS) register (see page 1192). Both FIFOs can be individually configured to trigger interrupts at different levels. Available configurations include ⅛, ¼, ½, ¾, and ⅞. For example, if the ¼ option is selected for the receive FIFO, the UART generates a receive interrupt after 4 data bytes are received. Out of reset, both FIFOs are configured to trigger an interrupt at the ½ mark. 16.3.9 Interrupts The UART can generate interrupts when the following conditions are observed: ■ Overrun Error ■ Break Error ■ Parity Error ■ Framing Error ■ Receive Timeout ■ Transmit (when condition defined in the TXIFLSEL bit in the UARTIFLS register is met, or if the EOT bit in UARTCTL is set, when the last bit of all transmitted data leaves the serializer) ■ Receive (when condition defined in the RXIFLSEL bit in the UARTIFLS register is met) All of the interrupt events are ORed together before being sent to the interrupt controller, so the UART can only generate a single interrupt request to the controller at any given time. Software can service multiple interrupt events in a single interrupt service routine by reading the UART Masked Interrupt Status (UARTMIS) register (see page 1202). The interrupt events that can trigger a controller-level interrupt are defined in the UART Interrupt Mask (UARTIM) register (see page 1194) by setting the corresponding IM bits. If interrupts are not used, the raw interrupt status is visible via the UART Raw Interrupt Status (UARTRIS) register (see page 1198). Note: For receive timeout, the RTIM bit in the UARTIM register must be set to see the RTMIS and RTRIS status in the UARTMIS and UARTRIS registers. Interrupts are always cleared (for both the UARTMIS and UARTRIS registers) by writing a 1 to the corresponding bit in the UART Interrupt Clear (UARTICR) register (see page 1206). The receive timeout interrupt is asserted when the receive FIFO is not empty, and no further data is received over a 32-bit period when the HSE bit is clear or over a 64-bit period when the HSE bit is set. The receive timeout interrupt is cleared either when the FIFO becomes empty through reading all the data (or by reading the holding register), or when a 1 is written to the corresponding bit in the UARTICR register. The receive interrupt changes state when one of the following events occurs: ■ If the FIFOs are enabled and the receive FIFO reaches the programmed trigger level, the RXRIS bit is set. The receive interrupt is cleared by reading data from the receive FIFO until it becomes less than the trigger level, or by clearing the interrupt by writing a 1 to the RXIC bit. 1170 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ If the FIFOs are disabled (have a depth of one location) and data is received thereby filling the location, the RXRIS bit is set. The receive interrupt is cleared by performing a single read of the receive FIFO, or by clearing the interrupt by writing a 1 to the RXIC bit. The transmit interrupt changes state when one of the following events occurs: ■ If the FIFOs are enabled and the transmit FIFO progresses through the programmed trigger level, the TXRIS bit is set. The transmit interrupt is based on a transition through level, therefore the FIFO must be written past the programmed trigger level otherwise no further transmit interrupts will be generated. The transmit interrupt is cleared by writing data to the transmit FIFO until it becomes greater than the trigger level, or by clearing the interrupt by writing a 1 to the TXIC bit. ■ If the FIFOs are disabled (have a depth of one location) and there is no data present in the transmitters single location, the TXRIS bit is set. It is cleared by performing a single write to the transmit FIFO, or by clearing the interrupt by writing a 1 to the TXIC bit. 16.3.10 Loopback Operation The UART can be placed into an internal loopback mode for diagnostic or debug work by setting the LBE bit in the UARTCTL register (see page 1188). In loopback mode, data transmitted on the UnTx output is received on the UnRx input. Note that the LBE bit should be set before the UART is enabled. 16.3.11 DMA Operation The UART provides an interface to the μDMA controller with separate channels for transmit and receive. The DMA operation of the UART is enabled through the UART DMA Control (UARTDMACTL) register. When DMA operation is enabled, the UART asserts a DMA request on the receive or transmit channel when the associated FIFO can transfer data. For the receive channel, a single transfer request is asserted whenever any data is in the receive FIFO. A burst transfer request is asserted whenever the amount of data in the receive FIFO is at or above the FIFO trigger level configured in the UARTIFLS register. For the transmit channel, a single transfer request is asserted whenever there is at least one empty location in the transmit FIFO. The burst request is asserted whenever the transmit FIFO contains fewer characters than the FIFO trigger level. The single and burst DMA transfer requests are handled automatically by the μDMA controller depending on how the DMA channel is configured. To enable DMA operation for the receive channel, set the RXDMAE bit of the DMA Control (UARTDMACTL) register. To enable DMA operation for the transmit channel, set the TXDMAE bit of the UARTDMACTL register. The UART can also be configured to stop using DMA for the receive channel if a receive error occurs. If the DMAERR bit of the UARTDMACR register is set and a receive error occurs, the DMA receive requests are automatically disabled. This error condition can be cleared by clearing the appropriate UART error interrupt. When the µDMA is finished transferring data to the TX FIFO or from the RX FIFO, a dma_done signal is sent to the UART to indicate completion. The dma_done status is indicated through the DMATXRIS and DMARXIS bits of the UARTRIS register. An interrupt can be generated from these status bits by setting the DMATXIM and/or DMARXIM bits in the UARTIM register. Note: The DMATXRIS bit can be used to indicate the µDMA's completion of data transfer to the TX FIFO. To indicate transfer completion from the UART's serializer, the end-of-transmission bit (EOT bit) should be enabled in the UARTCTL register. An interrupt can be generated on an end-of-transmission completion by setting the EOTIM bit of the UARTIM register. See “Micro Direct Memory Access (μDMA)” on page 678 for more details about programming the μDMA controller. June 18, 2014 1171 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) 16.4 Initialization and Configuration To enable and initialize the UART, the following steps are necessary: 1. Enable the UART module using the RCGCUART register (see page 388). 2. Enable the clock to the appropriate GPIO module via the RCGCGPIO register (see page 382). To find out which GPIO port to enable, refer to Table 26-5 on page 1808. 3. Set the GPIO AFSEL bits for the appropriate pins (see page 770). To determine which GPIOs to configure, see Table 26-4 on page 1797. 4. Configure the GPIO current level and/or slew rate as specified for the mode selected (see page 772 and page 780). 5. Configure the PMCn fields in the GPIOPCTL register to assign the UART signals to the appropriate pins (see page 787 and Table 26-5 on page 1808). To use the UART, the peripheral clock must be enabled by setting the appropriate bit in the RCGCUART register (page 388). In addition, the clock to the appropriate GPIO module must be enabled via the RCGCGPIO register (page 382) in the System Control module. To find out which GPIO port to enable, refer to Table 26-5 on page 1808. This section discusses the steps that are required to use a UART module. For this example, the UART clock is assumed to be 20 MHz, and the desired UART configuration is: ■ 115200 baud rate ■ Data length of 8 bits ■ One stop bit ■ No parity ■ FIFOs disabled ■ No interrupts The first thing to consider when programming the UART is the baud-rate divisor (BRD), because the UARTIBRD and UARTFBRD registers must be written before the UARTLCRH register. Using the equation described in “Baud-Rate Generation” on page 1165, the BRD can be calculated: BRD = 20,000,000 / (16 * 115,200) = 10.8507 which means that the DIVINT field of the UARTIBRD register (see page 1184) should be set to 10 decimal or 0xA. The value to be loaded into the UARTFBRD register (see page 1185) is calculated by the equation: UARTFBRD[DIVFRAC] = integer(0.8507 * 64 + 0.5) = 54 With the BRD values in hand, the UART configuration is written to the module in the following order: 1. Disable the UART by clearing the UARTEN bit in the UARTCTL register. 2. Write the integer portion of the BRD to the UARTIBRD register. 3. Write the fractional portion of the BRD to the UARTFBRD register. 1172 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 4. Write the desired serial parameters to the UARTLCRH register (in this case, a value of 0x0000.0060). 5. Configure the UART clock source by writing to the UARTCC register. 6. Optionally, configure the µDMA channel (see “Micro Direct Memory Access (μDMA)” on page 678) and enable the DMA option(s) in the UARTDMACTL register. 7. Enable the UART by setting the UARTEN bit in the UARTCTL register. 16.5 Register Map Table 16-3 on page 1173 lists the UART registers. The offset listed is a hexadecimal increment to the register's address, relative to that UART's base address: ■ ■ ■ ■ ■ ■ ■ ■ UART0: 0x4000.C000 UART1: 0x4000.D000 UART2: 0x4000.E000 UART3: 0x4000.F000 UART4: 0x4001.0000 UART5: 0x4001.1000 UART6: 0x4001.2000 UART7: 0x4001.3000 The UART module clock must be enabled before the registers can be programmed (see page 388). There must be a delay of 3 system clocks after the UART module clock is enabled before any UART module registers are accessed. The UART must be disabled (see the UARTEN bit in the UARTCTL register on page 1188) before any of the control registers are reprogrammed. When the UART is disabled during a TX or RX operation, the current transaction is completed prior to the UART stopping. Note: Registers that contain bits for modem control or status only apply to the following UARTs: ■ UART0 (modem flow control and modem status) ■ UART1 (modem flow control and modem status) ■ UART2 (modem flow control) ■ UART3 (modem flow control) ■ UART4 (modem flow control) Table 16-3. UART Register Map Type Reset Description See page UARTDR RW 0x0000.0000 UART Data 1175 0x004 UARTRSR/UARTECR RW 0x0000.0000 UART Receive Status/Error Clear 1177 0x018 UARTFR RO 0x0000.0090 UART Flag 1180 0x020 UARTILPR RW 0x0000.0000 UART IrDA Low-Power Register 1183 Offset Name 0x000 June 18, 2014 1173 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Table 16-3. UART Register Map (continued) Description See page 0x0000.0000 UART Integer Baud-Rate Divisor 1184 RW 0x0000.0000 UART Fractional Baud-Rate Divisor 1185 UARTLCRH RW 0x0000.0000 UART Line Control 1186 0x030 UARTCTL RW 0x0000.0300 UART Control 1188 0x034 UARTIFLS RW 0x0000.0012 UART Interrupt FIFO Level Select 1192 0x038 UARTIM RW 0x0000.0000 UART Interrupt Mask 1194 0x03C UARTRIS RO 0x0000.0000 UART Raw Interrupt Status 1198 0x040 UARTMIS RO 0x0000.0000 UART Masked Interrupt Status 1202 0x044 UARTICR W1C 0x0000.0000 UART Interrupt Clear 1206 0x048 UARTDMACTL RW 0x0000.0000 UART DMA Control 1208 0x0A4 UART9BITADDR RW 0x0000.0000 UART 9-Bit Self Address 1209 0x0A8 UART9BITAMASK RW 0x0000.00FF UART 9-Bit Self Address Mask 1210 0xFC0 UARTPP RO 0x0000.000F UART Peripheral Properties 1211 0xFC8 UARTCC RW 0x0000.0000 UART Clock Configuration 1213 0xFD0 UARTPeriphID4 RO 0x0000.0060 UART Peripheral Identification 4 1214 0xFD4 UARTPeriphID5 RO 0x0000.0000 UART Peripheral Identification 5 1215 0xFD8 UARTPeriphID6 RO 0x0000.0000 UART Peripheral Identification 6 1216 0xFDC UARTPeriphID7 RO 0x0000.0000 UART Peripheral Identification 7 1217 0xFE0 UARTPeriphID0 RO 0x0000.0011 UART Peripheral Identification 0 1218 0xFE4 UARTPeriphID1 RO 0x0000.0000 UART Peripheral Identification 1 1219 0xFE8 UARTPeriphID2 RO 0x0000.0018 UART Peripheral Identification 2 1220 0xFEC UARTPeriphID3 RO 0x0000.0001 UART Peripheral Identification 3 1221 0xFF0 UARTPCellID0 RO 0x0000.000D UART PrimeCell Identification 0 1222 0xFF4 UARTPCellID1 RO 0x0000.00F0 UART PrimeCell Identification 1 1223 0xFF8 UARTPCellID2 RO 0x0000.0005 UART PrimeCell Identification 2 1224 0xFFC UARTPCellID3 RO 0x0000.00B1 UART PrimeCell Identification 3 1225 Offset Name Type Reset 0x024 UARTIBRD RW 0x028 UARTFBRD 0x02C 16.6 Register Descriptions The remainder of this section lists and describes the UART registers, in numerical order by address offset. 1174 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: UART Data (UARTDR), offset 0x000 Important: This register is read-sensitive. See the register description for details. This register is the data register (the interface to the FIFOs). For transmitted data, if the FIFO is enabled, data written to this location is pushed onto the transmit FIFO. If the FIFO is disabled, data is stored in the transmitter holding register (the bottom word of the transmit FIFO). A write to this register initiates a transmission from the UART. For received data, if the FIFO is enabled, the data byte and the 4-bit status (break, frame, parity, and overrun) is pushed onto the 12-bit wide receive FIFO. If the FIFO is disabled, the data byte and status are stored in the receiving holding register (the bottom word of the receive FIFO). The received data can be retrieved by reading this register. UART Data (UARTDR) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 11 10 9 8 OE BE PE FE RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 11 OE RO 0 DATA RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Overrun Error Value Description 0 No data has been lost due to a FIFO overrun. 1 New data was received when the FIFO was full, resulting in data loss. June 18, 2014 1175 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset 10 BE RO 0 Description UART Break Error Value Description 0 No break condition has occurred 1 A break condition has been detected, indicating that the receive data input was held Low for longer than a full-word transmission time (defined as start, data, parity, and stop bits). In FIFO mode, this error is associated with the character at the top of the FIFO. When a break occurs, only one 0 character is loaded into the FIFO. The next character is only enabled after the received data input goes to a 1 (marking state), and the next valid start bit is received. 9 PE RO 0 UART Parity Error Value Description 0 No parity error has occurred 1 The parity of the received data character does not match the parity defined by bits 2 and 7 of the UARTLCRH register. In FIFO mode, this error is associated with the character at the top of the FIFO. 8 FE RO 0 UART Framing Error Value Description 7:0 DATA RW 0x00 0 No framing error has occurred 1 The received character does not have a valid stop bit (a valid stop bit is 1). Data Transmitted or Received Data that is to be transmitted via the UART is written to this field. When read, this field contains the data that was received by the UART. 1176 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: UART Receive Status/Error Clear (UARTRSR/UARTECR), offset 0x004 The UARTRSR/UARTECR register is the receive status register/error clear register. In addition to the UARTDR register, receive status can also be read from the UARTRSR register. If the status is read from this register, then the status information corresponds to the entry read from UARTDR prior to reading UARTRSR. The status information for overrun is set immediately when an overrun condition occurs. The UARTRSR register cannot be written. A write of any value to the UARTECR register clears the framing, parity, break, and overrun errors. All the bits are cleared on reset. Read-Only Status Register UART Receive Status/Error Clear (UARTRSR/UARTECR) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x004 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 OE BE PE FE RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 OE RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Overrun Error Value Description 0 No data has been lost due to a FIFO overrun. 1 New data was received when the FIFO was full, resulting in data loss. This bit is cleared by a write to UARTECR. The FIFO contents remain valid because no further data is written when the FIFO is full, only the contents of the shift register are overwritten. The CPU must read the data in order to empty the FIFO. June 18, 2014 1177 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset 2 BE RO 0 Description UART Break Error Value Description 0 No break condition has occurred 1 A break condition has been detected, indicating that the receive data input was held Low for longer than a full-word transmission time (defined as start, data, parity, and stop bits). This bit is cleared to 0 by a write to UARTECR. In FIFO mode, this error is associated with the character at the top of the FIFO. When a break occurs, only one 0 character is loaded into the FIFO. The next character is only enabled after the receive data input goes to a 1 (marking state) and the next valid start bit is received. 1 PE RO 0 UART Parity Error Value Description 0 No parity error has occurred 1 The parity of the received data character does not match the parity defined by bits 2 and 7 of the UARTLCRH register. This bit is cleared to 0 by a write to UARTECR. 0 FE RO 0 UART Framing Error Value Description 0 No framing error has occurred 1 The received character does not have a valid stop bit (a valid stop bit is 1). This bit is cleared to 0 by a write to UARTECR. In FIFO mode, this error is associated with the character at the top of the FIFO. Write-Only Error Clear Register UART Receive Status/Error Clear (UARTRSR/UARTECR) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x004 Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 WO 0 WO 0 WO 0 WO 0 3 2 1 0 WO 0 WO 0 WO 0 WO 0 reserved Type Reset WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset WO 0 WO 0 WO 0 WO 0 WO 0 DATA WO 0 WO 0 WO 0 WO 0 WO 0 1178 WO 0 WO 0 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 31:8 reserved WO 0x0000.00 7:0 DATA WO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Error Clear A write to this register of any data clears the framing, parity, break, and overrun flags. June 18, 2014 1179 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 3: UART Flag (UARTFR), offset 0x018 The UARTFR register is the flag register. After reset, the TXFF, RXFF, and BUSY bits are 0, and TXFE and RXFE bits are 1. Note: Registers that contain bits for modem control or status only apply to the following UARTs: ■ UART0 (modem flow control and modem status) ■ UART1 (modem flow control and modem status) ■ UART2 (modem flow control) ■ UART3 (modem flow control) ■ UART4 (modem flow control) UART Flag (UARTFR) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x018 Type RO, reset 0x0000.0090 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RI TXFE RXFF TXFF RXFE BUSY DCD DSR CTS RO 0 RO 1 RO 0 RO 0 RO 1 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:9 reserved RO 0x0000.00 8 RI RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Ring Indicator Value Description 0 The UnRI signal is not asserted. 1 The UnRI signal is asserted. 1180 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 7 TXFE RO 1 Description UART Transmit FIFO Empty The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register. Value Description 0 The transmitter has data to transmit. 1 If the FIFO is disabled (FEN is 0), the transmit holding register is empty. If the FIFO is enabled (FEN is 1), the transmit FIFO is empty. 6 RXFF RO 0 UART Receive FIFO Full The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register. Value Description 0 The receiver can receive data. 1 If the FIFO is disabled (FEN is 0), the receive holding register is full. If the FIFO is enabled (FEN is 1), the receive FIFO is full. 5 TXFF RO 0 UART Transmit FIFO Full The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register. Value Description 0 The transmitter is not full. 1 If the FIFO is disabled (FEN is 0), the transmit holding register is full. If the FIFO is enabled (FEN is 1), the transmit FIFO is full. 4 RXFE RO 1 UART Receive FIFO Empty The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register. Value Description 0 The receiver is not empty. 1 If the FIFO is disabled (FEN is 0), the receive holding register is empty. If the FIFO is enabled (FEN is 1), the receive FIFO is empty. June 18, 2014 1181 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset Description 3 BUSY RO 0 UART Busy Value Description 0 The UART is not busy. 1 The UART is busy transmitting data. This bit remains set until the complete byte, including all stop bits, has been sent from the shift register. This bit is set as soon as the transmit FIFO becomes non-empty (regardless of whether UART is enabled). 2 DCD RO 0 Data Carrier Detect Value Description 1 DSR RO 0 0 The UnDCD signal is not asserted. 1 The UnDCD signal is asserted. Data Set Ready Value Description 0 CTS RO 0 0 The UnDSR signal is not asserted. 1 The UnDSR signal is asserted. Clear To Send Value Description 0 The U1CTS signal is not asserted. 1 The UnCTS signal is asserted. 1182 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 4: UART IrDA Low-Power Register (UARTILPR), offset 0x020 The UARTILPR register stores the 8-bit low-power counter divisor value used to derive the low-power SIR pulse width clock by dividing down the system clock (SysClk). All the bits are cleared when reset. The internal IrLPBaud16 clock is generated by dividing down SysClk according to the low-power divisor value written to UARTILPR. The duration of SIR pulses generated when low-power mode is enabled is three times the period of the IrLPBaud16 clock. The low-power divisor value is calculated as follows: ILPDVSR = SysClk / FIrLPBaud16 where FIrLPBaud16 is nominally 1.8432 MHz. Because the IrLPBaud16 clock is used to sample transmitted data irrespective of mode, the ILPDVSR field must be programmed in both low power and normal mode,such that 1.42 MHz < FIrLPBaud16 < 2.12 MHz, resulting in a low-power pulse duration of 1.41–2.11 μs (three times the period of IrLPBaud16). The minimum frequency of IrLPBaud16 ensures that pulses less than one period of IrLPBaud16 are rejected, but pulses greater than 1.4 μs are accepted as valid pulses. Note: Zero is an illegal value. Programming a zero value results in no IrLPBaud16 pulses being generated. UART IrDA Low-Power Register (UARTILPR) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x020 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset ILPDVSR RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 ILPDVSR RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. IrDA Low-Power Divisor This field contains the 8-bit low-power divisor value. June 18, 2014 1183 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 5: UART Integer Baud-Rate Divisor (UARTIBRD), offset 0x024 The UARTIBRD register is the integer part of the baud-rate divisor value. All the bits are cleared on reset. The minimum possible divide ratio is 1 (when UARTIBRD=0), in which case the UARTFBRD register is ignored. When changing the UARTIBRD register, the new value does not take effect until transmission/reception of the current character is complete. Any changes to the baud-rate divisor must be followed by a write to the UARTLCRH register. See “Baud-Rate Generation” on page 1165 for configuration details. UART Integer Baud-Rate Divisor (UARTIBRD) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 DIVINT Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 DIVINT RW 0x0000 Integer Baud-Rate Divisor 1184 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 6: UART Fractional Baud-Rate Divisor (UARTFBRD), offset 0x028 The UARTFBRD register is the fractional part of the baud-rate divisor value. All the bits are cleared on reset. When changing the UARTFBRD register, the new value does not take effect until transmission/reception of the current character is complete. Any changes to the baud-rate divisor must be followed by a write to the UARTLCRH register. See “Baud-Rate Generation” on page 1165 for configuration details. UART Fractional Baud-Rate Divisor (UARTFBRD) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x028 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 DIVFRAC RO 0 Bit/Field Name Type Reset 31:6 reserved RO 0x0000.000 5:0 DIVFRAC RW 0x0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Fractional Baud-Rate Divisor June 18, 2014 1185 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 7: UART Line Control (UARTLCRH), offset 0x02C The UARTLCRH register is the line control register. Serial parameters such as data length, parity, and stop bit selection are implemented in this register. When updating the baud-rate divisor (UARTIBRD and/or UARTIFRD), the UARTLCRH register must also be written. The write strobe for the baud-rate divisor registers is tied to the UARTLCRH register. UART Line Control (UARTLCRH) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x02C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 FEN STP2 EPS PEN BRK RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset SPS RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 SPS RW 0 RW 0 WLEN RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Stick Parity Select When bits 1, 2, and 7 of UARTLCRH are set, the parity bit is transmitted and checked as a 0. When bits 1 and 7 are set and 2 is cleared, the parity bit is transmitted and checked as a 1. When this bit is cleared, stick parity is disabled. 6:5 WLEN RW 0x0 UART Word Length The bits indicate the number of data bits transmitted or received in a frame as follows: Value Description 0x0 5 bits (default) 0x1 6 bits 0x2 7 bits 0x3 8 bits 1186 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 FEN RW 0 Description UART Enable FIFOs Value Description 3 STP2 RW 0 0 The FIFOs are disabled (Character mode). The FIFOs become 1-byte-deep holding registers. 1 The transmit and receive FIFO buffers are enabled (FIFO mode). UART Two Stop Bits Select Value Description 0 One stop bit is transmitted at the end of a frame. 1 Two stop bits are transmitted at the end of a frame. The receive logic does not check for two stop bits being received. When in 7816 smartcard mode (the SMART bit is set in the UARTCTL register), the number of stop bits is forced to 2. 2 EPS RW 0 UART Even Parity Select Value Description 0 Odd parity is performed, which checks for an odd number of 1s. 1 Even parity generation and checking is performed during transmission and reception, which checks for an even number of 1s in data and parity bits. This bit has no effect when parity is disabled by the PEN bit. 1 PEN RW 0 UART Parity Enable Value Description 0 BRK RW 0 0 Parity is disabled and no parity bit is added to the data frame. 1 Parity checking and generation is enabled. UART Send Break Value Description 0 Normal use. 1 A Low level is continually output on the UnTx signal, after completing transmission of the current character. For the proper execution of the break command, software must set this bit for at least two frames (character periods). June 18, 2014 1187 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 8: UART Control (UARTCTL), offset 0x030 The UARTCTL register is the control register. All the bits are cleared on reset except for the Transmit Enable (TXE) and Receive Enable (RXE) bits, which are set. To enable the UART module, the UARTEN bit must be set. If software requires a configuration change in the module, the UARTEN bit must be cleared before the configuration changes are written. If the UART is disabled during a transmit or receive operation, the current transaction is completed prior to the UART stopping. Note: Registers that contain bits for modem control or status only apply to the following UARTs: ■ UART0 (modem flow control and modem status) ■ UART1 (modem flow control and modem status) ■ UART2 (modem flow control) ■ UART3 (modem flow control) ■ UART4 (modem flow control) Note: The UARTCTL register should not be changed while the UART is enabled or else the results are unpredictable. The following sequence is recommended for making changes to the UARTCTL register. 1. Disable the UART. 2. Wait for the end of transmission or reception of the current character. 3. Flush the transmit FIFO by clearing bit 4 (FEN) in the line control register (UARTLCRH). 4. Reprogram the control register. 5. Enable the UART. UART Control (UARTCTL) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x030 Type RW, reset 0x0000.0300 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 CTSEN RTSEN RTS DTR RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RXE TXE LBE reserved HSE EOT SMART SIRLP SIREN UARTEN RW 1 RW 1 RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset Type Reset reserved RO 0 RO 0 1188 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 CTSEN RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Enable Clear To Send Value Description 14 RTSEN RW 0 0 CTS hardware flow control is disabled. 1 CTS hardware flow control is enabled. Data is only transmitted when the UnCTS signal is asserted. Enable Request to Send Value Description 0 RTS hardware flow control is disabled. 1 RTS hardware flow control is enabled. Data is only requested (by asserting UnRTS) when the receive FIFO has available entries. 13:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 RTS RW 0 Request to Send When RTSEN is clear, the status of this bit is reflected on the U1RTS signal. If RTSEN is set, this bit is ignored on a write and should be ignored on read. 10 DTR RW 0 Data Terminal Ready This bit sets the state of the UnDTR output. 9 RXE RW 1 UART Receive Enable Value Description 0 The receive section of the UART is disabled. 1 The receive section of the UART is enabled. If the UART is disabled in the middle of a receive, it completes the current character before stopping. Note: 8 TXE RW 1 To enable reception, the UARTEN bit must also be set. UART Transmit Enable Value Description 0 The transmit section of the UART is disabled. 1 The transmit section of the UART is enabled. If the UART is disabled in the middle of a transmission, it completes the current character before stopping. Note: To enable transmission, the UARTEN bit must also be set. June 18, 2014 1189 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset 7 LBE RW 0 Description UART Loop Back Enable Value Description 0 Normal operation. 1 The UnTx path is fed through the UnRx path. 6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5 HSE RW 0 High-Speed Enable Value Description 0 The UART is clocked using the system clock divided by 16. 1 The UART is clocked using the system clock divided by 8. Note: System clock used is also dependent on the baud-rate divisor configuration (see page 1184) and page 1185). The state of this bit has no effect on clock generation in ISO 7816 smart card mode (the SMART bit is set). 4 EOT RW 0 End of Transmission This bit determines the behavior of the TXRIS bit in the UARTRIS register. Value Description 3 SMART RW 0 0 The TXRIS bit is set when the transmit FIFO condition specified in UARTIFLS is met. 1 The TXRIS bit is set only after all transmitted data, including stop bits, have cleared the serializer. ISO 7816 Smart Card Support Value Description 0 Normal operation. 1 The UART operates in Smart Card mode. The application must ensure that it sets 8-bit word length (WLEN set to 0x3) and even parity (PEN set to 1, EPS set to 1, SPS set to 0) in UARTLCRH when using ISO 7816 mode. In this mode, the value of the STP2 bit in UARTLCRH is ignored and the number of stop bits is forced to 2. Note that the UART does not support automatic retransmission on parity errors. If a parity error is detected on transmission, all further transmit operations are aborted and software must handle retransmission of the affected byte or message. 1190 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2 SIRLP RW 0 Description UART SIR Low-Power Mode This bit selects the IrDA encoding mode. Value Description 0 Low-level bits are transmitted as an active High pulse with a width of 3/16th of the bit period. 1 The UART operates in SIR Low-Power mode. Low-level bits are transmitted with a pulse width which is 3 times the period of the IrLPBaud16 input signal, regardless of the selected bit rate. Setting this bit uses less power, but might reduce transmission distances. See page 1183 for more information. 1 SIREN RW 0 UART SIR Enable Value Description 0 UARTEN RW 0 0 Normal operation. 1 The IrDA SIR block is enabled, and the UART will transmit and receive data using SIR protocol. UART Enable Value Description 0 The UART is disabled. 1 The UART is enabled. If the UART is disabled in the middle of transmission or reception, it completes the current character before stopping. June 18, 2014 1191 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 9: UART Interrupt FIFO Level Select (UARTIFLS), offset 0x034 The UARTIFLS register is the interrupt FIFO level select register. You can use this register to define the FIFO level at which the TXRIS and RXRIS bits in the UARTRIS register are triggered. The interrupts are generated based on a transition through a level rather than being based on the level. That is, the interrupts are generated when the fill level progresses through the trigger level. For example, if the receive trigger level is set to the half-way mark, the interrupt is triggered as the module is receiving the 9th character. Out of reset, the TXIFLSEL and RXIFLSEL bits are configured so that the FIFOs trigger an interrupt at the half-way mark. UART Interrupt FIFO Level Select (UARTIFLS) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x034 Type RW, reset 0x0000.0012 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RXIFLSEL RO 0 Bit/Field Name Type Reset 31:6 reserved RO 0x0000.00 5:3 RXIFLSEL RW 0x2 RO 0 RO 0 RO 0 RW 0 RW 1 TXIFLSEL RW 0 RW 0 RW 1 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Receive Interrupt FIFO Level Select The trigger points for the receive interrupt are as follows: Value Description 0x0 RX FIFO ≥ ⅛ full 0x1 RX FIFO ≥ ¼ full 0x2 RX FIFO ≥ ½ full (default) 0x3 RX FIFO ≥ ¾ full 0x4 RX FIFO ≥ ⅞ full 0x5-0x7 Reserved 1192 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2:0 TXIFLSEL RW 0x2 Description UART Transmit Interrupt FIFO Level Select The trigger points for the transmit interrupt are as follows: Value Description 0x0 TX FIFO ≤ ⅞ empty 0x1 TX FIFO ≤ ¾ empty 0x2 TX FIFO ≤ ½ empty (default) 0x3 TX FIFO ≤ ¼ empty 0x4 TX FIFO ≤ ⅛ empty 0x5-0x7 Reserved Note: If the EOT bit in UARTCTL is set (see page 1188), the transmit interrupt is generated once the FIFO is completely empty and all data including stop bits have left the transmit serializer. In this case, the setting of TXIFLSEL is ignored. June 18, 2014 1193 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 10: UART Interrupt Mask (UARTIM), offset 0x038 The UARTIM register is the interrupt mask set/clear register. On a read, this register gives the current value of the mask on the relevant interrupt. Setting a bit allows the corresponding raw interrupt signal to be routed to the interrupt controller. Clearing a bit prevents the raw interrupt signal from being sent to the interrupt controller. Note: Registers that contain bits for modem control or status only apply to the following UARTs: ■ UART0 (modem flow control and modem status) ■ UART1 (modem flow control and modem status) ■ UART2 (modem flow control) ■ UART3 (modem flow control) ■ UART4 (modem flow control) UART Interrupt Mask (UARTIM) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x038 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 reserved Type Reset RO 0 15 RO 0 RO 0 14 13 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 17 16 DMATXIM DMARXIM RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 12 11 10 9 8 7 6 5 4 3 2 1 0 9BITIM EOTIM OEIM BEIM PEIM FEIM RTIM TXIM RXIM DSRIM DCDIM CTSIM RIIM RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RO 0 Bit/Field Name Type Reset Description 31:18 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 17 DMATXIM RW 0 Transmit DMA Interrupt Mask Value Description 0 The DMATXRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the DMATXRIS bit in the UARTRIS register is set. 1194 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 16 DMARXIM RW 0 Description Receive DMA Interrupt Mask Value Description 0 The DMARXRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the DMARXRIS bit in the UARTRIS register is set. 15:13 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 12 9BITIM RW 0 9-Bit Mode Interrupt Mask Value Description 11 EOTIM RW 0 0 The 9BITRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the 9BITRIS bit in the UARTRIS register is set. End of Transmission Interrupt Mask Value Description 10 OEIM RW 0 0 The EOTRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the EOTRIS bit in the UARTRIS register is set. UART Overrun Error Interrupt Mask Value Description 9 BEIM RW 0 0 The OERIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the OERIS bit in the UARTRIS register is set. UART Break Error Interrupt Mask Value Description 0 The BERIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the BERIS bit in the UARTRIS register is set. June 18, 2014 1195 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset 8 PEIM RW 0 Description UART Parity Error Interrupt Mask Value Description 7 FEIM RW 0 0 The PERIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PERIS bit in the UARTRIS register is set. UART Framing Error Interrupt Mask Value Description 6 RTIM RW 0 0 The FERIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the FERIS bit in the UARTRIS register is set. UART Receive Time-Out Interrupt Mask Value Description 5 TXIM RW 0 0 The RTRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the RTRIS bit in the UARTRIS register is set. UART Transmit Interrupt Mask Value Description 4 RXIM RW 0 0 The TXRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the TXRIS bit in the UARTRIS register is set. UART Receive Interrupt Mask Value Description 3 DSRIM RW 0 0 The RXRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the RXRIS bit in the UARTRIS register is set. UART Data Set Ready Modem Interrupt Mask Value Description 0 The DSRRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the DSRRIS bit in the UARTRIS register is set. 1196 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2 DCDIM RW 0 Description UART Data Carrier Detect Modem Interrupt Mask Value Description 1 CTSIM RW 0 0 The DCDRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the DCDRIS bit in the UARTRIS register is set. UART Clear to Send Modem Interrupt Mask Value Description 0 RIIM RW 0 0 The CTSRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the CTSRIS bit in the UARTRIS register is set. UART Ring Indicator Modem Interrupt Mask Value Description 0 The RIRIS interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the RIRIS bit in the UARTRIS register is set. June 18, 2014 1197 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 11: UART Raw Interrupt Status (UARTRIS), offset 0x03C The UARTRIS register is the raw interrupt status register. On a read, this register gives the current raw status value of the corresponding interrupt. A write has no effect. UART Raw Interrupt Status (UARTRIS) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x03C Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 reserved Type Reset RO 0 15 RO 0 RO 0 14 13 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 17 16 DMATXRIS DMARXRIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 12 11 10 9 8 7 6 5 4 3 2 1 0 9BITRIS EOTRIS OERIS BERIS PERIS FERIS RTRIS TXRIS RXRIS DSRRIS DCDRIS CTSRIS RIRIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:18 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 17 DMATXRIS RO 0 Transmit DMA Raw Interrupt Status Value Description 0 No interrupt 1 The transmit DMA has completed. This bit is cleared by writing a 1 to the DMATXIC bit in the UARTICR register. 16 DMARXRIS RO 0 Receive DMA Raw Interrupt Status Value Description 0 No interrupt 1 The receive DMA has completed. This bit is cleared by writing a 1 to the DMARXIC bit in the UARTICR register. 15:13 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1198 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 12 9BITRIS RO 0 Description 9-Bit Mode Raw Interrupt Status Value Description 0 No interrupt 1 A receive address match has occurred. This bit is cleared by writing a 1 to the 9BITIC bit in the UARTICR register. 11 EOTRIS RO 0 End of Transmission Raw Interrupt Status Value Description 0 No interrupt 1 The last bit of all transmitted data and flags has left the serializer. This bit is cleared by writing a 1 to the EOTIC bit in the UARTICR register. 10 OERIS RO 0 UART Overrun Error Raw Interrupt Status Value Description 0 No interrupt 1 An overrun error has occurred. This bit is cleared by writing a 1 to the OEIC bit in the UARTICR register. 9 BERIS RO 0 UART Break Error Raw Interrupt Status Value Description 0 No interrupt 1 A break error has occurred. This bit is cleared by writing a 1 to the BEIC bit in the UARTICR register. 8 PERIS RO 0 UART Parity Error Raw Interrupt Status Value Description 0 No interrupt 1 A parity error has occurred. This bit is cleared by writing a 1 to the PEIC bit in the UARTICR register. 7 FERIS RO 0 UART Framing Error Raw Interrupt Status Value Description 0 No interrupt 1 A framing error has occurred. This bit is cleared by writing a 1 to the FEIC bit in the UARTICR register. June 18, 2014 1199 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset 6 RTRIS RO 0 Description UART Receive Time-Out Raw Interrupt Status Value Description 0 No interrupt 1 A receive time out has occurred. This bit is cleared by writing a 1 to the RTIC bit in the UARTICR register. For receive timeout, the RTIM bit in the UARTIM register must be set to see the RTRIS status. 5 TXRIS RO 0 UART Transmit Raw Interrupt Status Value Description 0 No interrupt 1 If the EOT bit in the UARTCTL register is clear, the transmit FIFO level has passed through the condition defined in the UARTIFLS register. If the EOT bit is set, the last bit of all transmitted data and flags has left the serializer. This bit is cleared by writing a 1 to the TXIC bit in the UARTICR register or by writing data to the transmit FIFO until it becomes greater than the trigger level, if the FIFO is enabled, or by writing a single byte if the FIFO is disabled. 4 RXRIS RO 0 UART Receive Raw Interrupt Status Value Description 0 No interrupt 1 The receive FIFO level has passed through the condition defined in the UARTIFLS register. This bit is cleared by writing a 1 to the RXIC bit in the UARTICR register or by reading data from the receive FIFO until it becomes less than the trigger level, if the FIFO is enabled, or by reading a single byte if the FIFO is disabled. 3 DSRRIS RO 0 UART Data Set Ready Modem Raw Interrupt Status Value Description 0 No interrupt 1 Data Set Ready used for software flow control. This bit is cleared by writing a 1 to the DSRIC bit in the UARTICR register. 2 DCDRIS RO 0 UART Data Carrier Detect Modem Raw Interrupt Status Value Description 0 No interrupt 1 Data Carrier Detect used for software flow control. This bit is cleared by writing a 1 to the DCDIC bit in the UARTICR register. 1200 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1 CTSRIS RO 0 Description UART Clear to Send Modem Raw Interrupt Status Value Description 0 No interrupt 1 Clear to Send used for software flow control. This bit is cleared by writing a 1 to the CTSIC bit in the UARTICR register. 0 RIRIS RO 0 UART Ring Indicator Modem Raw Interrupt Status Value Description 0 No interrupt 1 Ring Indicator used for software flow control. This bit is cleared by writing a 1 to the RIIC bit in the UARTICR register. June 18, 2014 1201 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 12: UART Masked Interrupt Status (UARTMIS), offset 0x040 The UARTMIS register is the masked interrupt status register. On a read, this register gives the current masked status value of the corresponding interrupt. A write has no effect. UART Masked Interrupt Status (UARTMIS) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x040 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 reserved Type Reset RO 0 15 RO 0 RO 0 14 13 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 12 11 10 9 8 7 6 5 4 9BITMIS EOTMIS OEMIS BEMIS PEMIS FEMIS RTMIS TXMIS RXMIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 17 16 DMATXMIS DMARXMIS RO 0 RO 0 3 2 DSRMIS DCDMIS RO 0 RO 0 RO 0 RO 0 1 0 CTSMIS RIMIS RO 0 RO 0 Bit/Field Name Type Reset Description 31:18 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 17 DMATXMIS RO 0 Transmit DMA Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the completion of the transmit DMA. This bit is cleared by writing a 1 to the DMATXIC bit in the UARTICR register. 16 DMARXMIS RO 0 Receive DMA Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the completion of the receive DMA. This bit is cleared by writing a 1 to the DMARXIC bit in the UARTICR register. 15:13 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1202 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 12 9BITMIS RO 0 Description 9-Bit Mode Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a receive address match. This bit is cleared by writing a 1 to the 9BITIC bit in the UARTICR register. 11 EOTMIS RO 0 End of Transmission Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the transmission of the last data bit. This bit is cleared by writing a 1 to the EOTIC bit in the UARTICR register. 10 OEMIS RO 0 UART Overrun Error Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to an overrun error. This bit is cleared by writing a 1 to the OEIC bit in the UARTICR register. 9 BEMIS RO 0 UART Break Error Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a break error. This bit is cleared by writing a 1 to the BEIC bit in the UARTICR register. 8 PEMIS RO 0 UART Parity Error Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a parity error. This bit is cleared by writing a 1 to the PEIC bit in the UARTICR register. 7 FEMIS RO 0 UART Framing Error Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a framing error. This bit is cleared by writing a 1 to the FEIC bit in the UARTICR register. June 18, 2014 1203 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset 6 RTMIS RO 0 Description UART Receive Time-Out Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to a receive time out. This bit is cleared by writing a 1 to the RTIC bit in the UARTICR register. For receive timeout, the RTIM bit in the UARTIM register must be set to see the RTMIS status. 5 TXMIS RO 0 UART Transmit Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to passing through the specified transmit FIFO level (if the EOT bit is clear) or due to the transmission of the last data bit (if the EOT bit is set). This bit is cleared by writing a 1 to the TXIC bit in the UARTICR register or by writing data to the transmit FIFO until it becomes greater than the trigger level, if the FIFO is enabled, or by writing a single byte if the FIFO is disabled. 4 RXMIS RO 0 UART Receive Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to passing through the specified receive FIFO level. This bit is cleared by writing a 1 to the RXIC bit in the UARTICR register or by reading data from the receive FIFO until it becomes less than the trigger level, if the FIFO is enabled, or by reading a single byte if the FIFO is disabled. 3 DSRMIS RO 0 UART Data Set Ready Modem Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to Data Set Ready. This bit is cleared by writing a 1 to the DSRIC bit in the UARTICR register. 2 DCDMIS RO 0 UART Data Carrier Detect Modem Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to Data Carrier Detect. This bit is cleared by writing a 1 to the DCDIC bit in the UARTICR register. 1204 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1 CTSMIS RO 0 Description UART Clear to Send Modem Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to Clear to Send. This bit is cleared by writing a 1 to the CTSIC bit in the UARTICR register. 0 RIMIS RO 0 UART Ring Indicator Modem Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to Ring Indicator. This bit is cleared by writing a 1 to the RIIC bit in the UARTICR register. June 18, 2014 1205 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 13: UART Interrupt Clear (UARTICR), offset 0x044 The UARTICR register is the interrupt clear register. On a write of 1, the corresponding interrupt (both raw interrupt and masked interrupt, if enabled) is cleared. A write of 0 has no effect. Note that bits [3:0] are only implemented on UART1. These bits are reserved on UART0 and UART2. UART Interrupt Clear (UARTICR) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x044 Type W1C, reset 0x0000.0000 31 30 29 28 27 26 25 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9BITIC EOTIC RW 0 W1C 0 24 23 22 21 20 19 18 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 W1C 0 W1C 0 9 8 7 6 5 4 3 2 1 0 OEIC BEIC PEIC FEIC RTIC TXIC RXIC W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 W1C 0 reserved Type Reset reserved Type Reset RO 0 RO 0 RO 0 17 16 DMATXIC DMARXIC DSRMIC DCDMIC CTSMIC W1C 0 W1C 0 W1C 0 RIMIC W1C 0 Bit/Field Name Type Reset Description 31:18 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 17 DMATXIC W1C 0 Transmit DMA Interrupt Clear Writing a 1 to this bit clears the DMATXRIS bit in the UARTRIS register and the DMATXMIS bit in the UARTMIS register. 16 DMARXIC W1C 0 Receive DMA Interrupt Clear Writing a 1 to this bit clears the DMARXRIS bit in the UARTRIS register and the DMARXMIS bit in the UARTMIS register. 15:13 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 12 9BITIC RW 0 9-Bit Mode Interrupt Clear Writing a 1 to this bit clears the 9BITRIS bit in the UARTRIS register and the 9BITMIS bit in the UARTMIS register. 11 EOTIC W1C 0 End of Transmission Interrupt Clear Writing a 1 to this bit clears the EOTRIS bit in the UARTRIS register and the EOTMIS bit in the UARTMIS register. 10 OEIC W1C 0 Overrun Error Interrupt Clear Writing a 1 to this bit clears the OERIS bit in the UARTRIS register and the OEMIS bit in the UARTMIS register. 1206 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 9 BEIC W1C 0 Description Break Error Interrupt Clear Writing a 1 to this bit clears the BERIS bit in the UARTRIS register and the BEMIS bit in the UARTMIS register. 8 PEIC W1C 0 Parity Error Interrupt Clear Writing a 1 to this bit clears the PERIS bit in the UARTRIS register and the PEMIS bit in the UARTMIS register. 7 FEIC W1C 0 Framing Error Interrupt Clear Writing a 1 to this bit clears the FERIS bit in the UARTRIS register and the FEMIS bit in the UARTMIS register. 6 RTIC W1C 0 Receive Time-Out Interrupt Clear Writing a 1 to this bit clears the RTRIS bit in the UARTRIS register and the RTMIS bit in the UARTMIS register. 5 TXIC W1C 0 Transmit Interrupt Clear Writing a 1 to this bit clears the TXRIS bit in the UARTRIS register and the TXMIS bit in the UARTMIS register. 4 RXIC W1C 0 Receive Interrupt Clear Writing a 1 to this bit clears the RXRIS bit in the UARTRIS register and the RXMIS bit in the UARTMIS register. 3 DSRMIC W1C 0 UART Data Set Ready Modem Interrupt Clear Writing a 1 to this bit clears the DSRRIS bit in the UARTRIS register and the DSRMIS bit in the UARTMIS register. 2 DCDMIC W1C 0 UART Data Carrier Detect Modem Interrupt Clear Writing a 1 to this bit clears the DCDRIS bit in the UARTRIS register and the DCDMIS bit in the UARTMIS register. 1 CTSMIC W1C 0 UART Clear to Send Modem Interrupt Clear Writing a 1 to this bit clears the CTSRIS bit in the UARTRIS register and the CTSMIS bit in the UARTMIS register. 0 RIMIC W1C 0 UART Ring Indicator Modem Interrupt Clear Writing a 1 to this bit clears the RIRIS bit in the UARTRIS register and the RIMIS bit in the UARTMIS register. June 18, 2014 1207 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 14: UART DMA Control (UARTDMACTL), offset 0x048 The UARTDMACTL register is the DMA control register. UART DMA Control (UARTDMACTL) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x048 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 5 4 3 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type 31:3 reserved RO 2 DMAERR RW RO 0 Reset DMAERR TXDMAE RXDMAE RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 Description 0x00000.000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 DMA on Error Value Description 1 TXDMAE RW 0 0 µDMA receive requests are unaffected when a receive error occurs. 1 µDMA receive requests are automatically disabled when a receive error occurs. Transmit DMA Enable Value Description 0 RXDMAE RW 0 0 µDMA for the transmit FIFO is disabled. 1 µDMA for the transmit FIFO is enabled. Receive DMA Enable Value Description 0 µDMA for the receive FIFO is disabled. 1 µDMA for the receive FIFO is enabled. 1208 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 15: UART 9-Bit Self Address (UART9BITADDR), offset 0x0A4 The UART9BITADDR register is used to write the specific address that should be matched with the receiving byte when the 9-bit Address Mask (UART9BITAMASK) is set to 0xFF. This register is used in conjunction with UART9BITAMASK to form a match for address-byte received. UART 9-Bit Self Address (UART9BITADDR) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x0A4 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 9BITEN Type Reset RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 6 5 4 reserved RO 0 RO 0 RO 0 ADDR RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 9BITEN RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Enable 9-Bit Mode Value Description 0 9-bit mode is disabled. 1 9-bit mode is enabled. 14:8 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7:0 ADDR RW 0x00 Self Address for 9-Bit Mode This field contains the address that should be matched when UART9BITAMASK is 0xFF. June 18, 2014 1209 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 16: UART 9-Bit Self Address Mask (UART9BITAMASK), offset 0x0A8 The UART9BITAMASK register is used to enable the address mask for 9-bit mode. The address bits are masked to create a set of addresses to be matched with the received address byte. UART 9-Bit Self Address Mask (UART9BITAMASK) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0x0A8 Type RW, reset 0x0000.00FF 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 1 RW 1 RW 1 RW 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 MASK RO 0 RO 0 RO 0 RO 0 RW 1 RW 1 RW 1 RW 1 Bit/Field Name Type Reset Description 31:8 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7:0 MASK RW 0xFF Self Address Mask for 9-Bit Mode This field contains the address mask that creates a set of addresses that should be matched. 1210 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 17: UART Peripheral Properties (UARTPP), offset 0xFC0 The UARTPP register provides information regarding the properties of the UART module. UART Peripheral Properties (UARTPP) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFC0 Type RO, reset 0x0000.000F 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 MSE MS NB SC RO 1 RO 1 RO 1 RO 1 Bit/Field Name Type Reset Description 31:4 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 MSE RO 0x1 Modem Support Extended Value Description 2 MS RO 0x1 0 The UART module does not provide extended support for modem control. 1 The UART module provides extended support for modem control including UARTnDTR, UARTnDSR, UARTnDCD, and UARTnRI. Modem Support Value Description 1 NB RO 0x1 0 The UART module does not provide support for modem control. 1 The UART module provides support for modem control including UARTnRTS and UARTnCTS. 9-Bit Support Value Description 0 The UART module does not provide support for the transmission of 9-bit data for RS-485 support. 1 The UART module provides support for the transmission of 9-bit data for RS-485 support. June 18, 2014 1211 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Bit/Field Name Type Reset 0 SC RO 0x1 Description Smart Card Support Value Description 0 The UART module does not provide smart card support. 1 The UART module provides smart card support. 1212 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 18: UART Clock Configuration (UARTCC), offset 0xFC8 The UARTCC register controls the baud clock source for the UART module. For more information, see the section called “Peripheral Clock Sources” on page 234. Note: If the PIOSC is used for the UART baud clock, the system clock frequency must be at least 9 MHz in Run mode. UART Clock Configuration (UARTCC) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFC8 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset CS Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 CS RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Baud Clock Source The following table specifies the source that generates for the UART baud clock: Value Description 0x0 System clock (based on clock source and divisor factor programmed in RSCLKCFG register in the System Control Module) 0x1-0x4 reserved 0x5 Alternate clock source as defined by ALTCLKCFG register in System Control Module. 0x5-0xF Reserved June 18, 2014 1213 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 19: UART Peripheral Identification 4 (UARTPeriphID4), offset 0xFD0 The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 4 (UARTPeriphID4) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFD0 Type RO, reset 0x0000.0060 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID4 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID4 RO 0x60 RO 0 RO 0 RO 1 RO 1 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [7:0] Can be used by software to identify the presence of this peripheral. 1214 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 20: UART Peripheral Identification 5 (UARTPeriphID5), offset 0xFD4 The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 5 (UARTPeriphID5) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFD4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID5 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID5 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [15:8] Can be used by software to identify the presence of this peripheral. June 18, 2014 1215 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 21: UART Peripheral Identification 6 (UARTPeriphID6), offset 0xFD8 The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 6 (UARTPeriphID6) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFD8 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID6 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID6 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [23:16] Can be used by software to identify the presence of this peripheral. 1216 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 22: UART Peripheral Identification 7 (UARTPeriphID7), offset 0xFDC The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 7 (UARTPeriphID7) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFDC Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID7 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID7 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [31:24] Can be used by software to identify the presence of this peripheral. June 18, 2014 1217 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 23: UART Peripheral Identification 0 (UARTPeriphID0), offset 0xFE0 The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 0 (UARTPeriphID0) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFE0 Type RO, reset 0x0000.0011 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID0 RO 0x11 RO 0 RO 0 RO 0 RO 0 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [7:0] Can be used by software to identify the presence of this peripheral. 1218 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 24: UART Peripheral Identification 1 (UARTPeriphID1), offset 0xFE4 The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 1 (UARTPeriphID1) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFE4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID1 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID1 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [15:8] Can be used by software to identify the presence of this peripheral. June 18, 2014 1219 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 25: UART Peripheral Identification 2 (UARTPeriphID2), offset 0xFE8 The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 2 (UARTPeriphID2) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFE8 Type RO, reset 0x0000.0018 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 1 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID2 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID2 RO 0x18 RO 0 RO 0 RO 0 RO 0 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [23:16] Can be used by software to identify the presence of this peripheral. 1220 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 26: UART Peripheral Identification 3 (UARTPeriphID3), offset 0xFEC The UARTPeriphIDn registers are hard-coded and the fields within the registers determine the reset values. UART Peripheral Identification 3 (UARTPeriphID3) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFEC Type RO, reset 0x0000.0001 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID3 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID3 RO 0x01 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART Peripheral ID Register [31:24] Can be used by software to identify the presence of this peripheral. June 18, 2014 1221 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 27: UART PrimeCell Identification 0 (UARTPCellID0), offset 0xFF0 The UARTPCellIDn registers are hard-coded and the fields within the registers determine the reset values. UART PrimeCell Identification 0 (UARTPCellID0) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFF0 Type RO, reset 0x0000.000D 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 1 RO 1 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID0 RO 0x0D RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART PrimeCell ID Register [7:0] Provides software a standard cross-peripheral identification system. 1222 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 28: UART PrimeCell Identification 1 (UARTPCellID1), offset 0xFF4 The UARTPCellIDn registers are hard-coded and the fields within the registers determine the reset values. UART PrimeCell Identification 1 (UARTPCellID1) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFF4 Type RO, reset 0x0000.00F0 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID1 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID1 RO 0xF0 RO 0 RO 1 RO 1 RO 1 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART PrimeCell ID Register [15:8] Provides software a standard cross-peripheral identification system. June 18, 2014 1223 Texas Instruments-Production Data Universal Asynchronous Receivers/Transmitters (UARTs) Register 29: UART PrimeCell Identification 2 (UARTPCellID2), offset 0xFF8 The UARTPCellIDn registers are hard-coded and the fields within the registers determine the reset values. UART PrimeCell Identification 2 (UARTPCellID2) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFF8 Type RO, reset 0x0000.0005 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 1 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID2 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID2 RO 0x05 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART PrimeCell ID Register [23:16] Provides software a standard cross-peripheral identification system. 1224 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 30: UART PrimeCell Identification 3 (UARTPCellID3), offset 0xFFC The UARTPCellIDn registers are hard-coded and the fields within the registers determine the reset values. UART PrimeCell Identification 3 (UARTPCellID3) UART0 base: 0x4000.C000 UART1 base: 0x4000.D000 UART2 base: 0x4000.E000 UART3 base: 0x4000.F000 UART4 base: 0x4001.0000 UART5 base: 0x4001.1000 UART6 base: 0x4001.2000 UART7 base: 0x4001.3000 Offset 0xFFC Type RO, reset 0x0000.00B1 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID3 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID3 RO 0xB1 RO 0 RO 1 RO 0 RO 1 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. UART PrimeCell ID Register [31:24] Provides software a standard cross-peripheral identification system. June 18, 2014 1225 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) 17 Quad Synchronous Serial Interface (QSSI) The TM4C1294NCPDT microcontroller includes four Quad-Synchronous Serial Interface (QSSI) modules. All four of the modules support Advanced and Bi-SSI interfaces as well as a Quad-SSI enhancement to provide faster throughput of data. The QSSI module acts as a master or slave interface for synchronous serial communication with peripheral devices that have either Freescale SPI, or Texas Instruments synchronous serial interfaces. The QSSI performs serial-to-parallel conversion on data received from a peripheral device. The transmit and receive paths are buffered with internal, independent FIFO memories allowing up to eight 16-bit values in Legacy mode and 8-bit values in Advanced, Bi-, and Quad-modes. The CPU can accesses data in these FIFOs as well as the QSSI's control and status information. A µDMA interface is also provided to allow the transmit and receive FIFOs to be programmed as source/destination addresses in the µDMA module. The TM4C1294NCPDT QSSI modules have the following features: ■ Four QSSI channels with Advanced, Bi- and Quad-SSI functionality ■ Programmable interface operation for Freescale SPI or Texas Instruments synchronous serial interfaces in Legacy Mode. Support for Freescale interface in Bi- and Quad-SSI mode. ■ Master or slave operation ■ Programmable clock bit rate and prescaler ■ Separate transmit and receive FIFOs, each 16 bits wide and 8 locations deep ■ Programmable data frame size from 4 to 16 bits ■ Internal loopback test mode for diagnostic/debug testing ■ Standard FIFO-based interrupts and End-of-Transmission interrupt ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for transmit and receive – Receive single request asserted when data is in the FIFO; burst request asserted when FIFO contains 4 entries – Transmit single request asserted when there is space in the FIFO; burst request asserted when four or more entries are available to be written in the FIFO – Maskable µDMA interrupts for receive and transmit complete ■ Global Alternate Clock (ALTCLK) resource or System Clock (SYSCLK) can be used to generate baud clock. 17.1 Block Diagram The following figure below shows a block diagram of an QSSI module with Advanced, Bi- and Quad-SSI. 1226 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 17-1. QSSI Module with Advanced, Bi-SSI and Quad-SSI Support DMA Request DMA Control SSIDMACTL Interrupt Interrupt Control TxFIFO 8 x 16 SSIIM SSIMIS SSIRIS SSIICR . . . Control/Status SSInXDAT3 SSICR0 SSICR1 SSISR SSInXDAT2 Transmit/ Receive Logic SSIDR RxFIFO 8 x 16 Clock Prescaler System Clock . . . SSInXDAT1/RX SSInXDAT0/TX SSInClk SSInFss Clock Control SSICPSR SSICC ALTCLK SSI Baud Clock Identification Registers SSIPCellID0 SSIPCellID1 SSIPCellID2 SSIPCellID3 17.2 SSIPeriphID0 SSIPeriphID1 SSIPeriphID2 SSIPeriphID3 SSIPeriphID4 SSIPeriphID5 SSIPeriphID6 SSIPeriphID7 Signal Description The following table lists the external signals of the QSSI module and describes the function of each. The QSSI signals are alternate functions for some GPIO signals and default to be GPIO signals at reset. The "Pin Mux/Pin Assignment" column in the following table lists the possible GPIO pin placements for the QSSI signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the QSSI function. The number in June 18, 2014 1227 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the QSSI signal to the specified GPIO port pin. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Note that for the QSSI module, when operating in Legacy Mode, SSInXDAT0 functions as SSInTX and SSInXDAT1 functions as SSInRX. Table 17-1. SSI Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description SSI0Clk 35 PA2 (15) I/O TTL SSI module 0 clock SSI0Fss 36 PA3 (15) I/O TTL SSI module 0 frame signal SSI0XDAT0 37 PA4 (15) I/O TTL SSI Module 0 Bi-directional Data Pin 0 (SSI0TX in Legacy SSI Mode). SSI0XDAT1 38 PA5 (15) I/O TTL SSI Module 0 Bi-directional Data Pin 1 (SSI0RX in Legacy SSI Mode). SSI0XDAT2 40 PA6 (13) I/O TTL SSI Module 0 Bi-directional Data Pin 2. SSI0XDAT3 41 PA7 (13) I/O TTL SSI Module 0 Bi-directional Data Pin 3. SSI1Clk 120 PB5 (15) I/O TTL SSI module 1 clock. SSI1Fss 121 PB4 (15) I/O TTL SSI module 1 frame signal. SSI1XDAT0 123 PE4 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 0 (SSI1TX in Legacy SSI Mode). SSI1XDAT1 124 PE5 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 1 (SSI1RX in Legacy SSI Mode). SSI1XDAT2 125 PD4 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 2. SSI1XDAT3 126 PD5 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 3. SSI2Clk 4 PD3 (15) I/O TTL SSI module 2 clock. SSI2Fss 3 PD2 (15) I/O TTL SSI module 2 frame signal. SSI2XDAT0 2 PD1 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 0 (SSI2TX in Legacy SSI Mode). SSI2XDAT1 1 PD0 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 1 (SSI2RX in Legacy SSI Mode). SSI2XDAT2 128 PD7 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 2. SSI2XDAT3 127 PD6 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 3. SSI3Clk 5 45 PQ0 (14) PF3 (14) I/O TTL SSI module 3 clock. SSI3Fss 6 44 PQ1 (14) PF2 (14) I/O TTL SSI module 3 frame signal. SSI3XDAT0 11 43 PQ2 (14) PF1 (14) I/O TTL SSI Module 3 Bi-directional Data Pin 0 (SSI3TX in Legacy SSI Mode). SSI3XDAT1 27 42 PQ3 (14) PF0 (14) I/O TTL SSI Module 3 Bi-directional Data Pin 1 (SSI3RX in Legacy SSI Mode). SSI3XDAT2 46 118 PF4 (14) PP0 (15) I/O TTL SSI Module 3 Bi-directional Data Pin 2. SSI3XDAT3 119 PP1 (15) I/O TTL SSI Module 3 Bi-directional Data Pin 3. 17.3 Functional Description The QSSI performs serial-to-parallel conversion on data received from a peripheral device. The CPU accesses data, control, and status information. The transmit and receive paths are buffered 1228 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller with internal FIFO memories allowing up to eight 16-bit values to be stored independently in both transmit and receive modes. The QSSI also supports the µDMA interface. The transmit and receive FIFOs can be programmed as destination/source addresses in the µDMA module. µDMA operation is enabled by setting the appropriate bit(s) in the SSIDMACTL register (see page 1260). 17.3.1 Bit Rate Generation The QSSI includes a programmable bit rate clock divider and prescaler to generate the serial output clock. Bit rates are supported to 2 MHz and higher, although maximum bit rate is determined by peripheral devices. The serial bit rate is derived by dividing down the input clock (SysClk). The clock is first divided by an even prescale value CPSDVSR from 2 to 254, which is programmed in the SSI Clock Prescale (SSICPSR) register (see page 1252). The clock is further divided by a value from 1 to 256, which is 1 + SCR, where SCR is the value programmed in the SSI Control 0 (SSICR0) register (see page 1245). The frequency of the output clock SSInClk is defined by: SSInClk = SysClk / (CPSDVSR * (1 + SCR)) Note: SYSCLK or ALTCLK is used as the source for the SSInClk depending on how the CS field in the SSI Clock Configuration (SSICC) register is configured. For master legacy mode, the SYSCLK or ALTCLK must be at least two times faster than the SSInClk, with the restriction that SSInClk cannot be faster than 60 MHz. For slave mode, SYSCLK or ALTCLK must be at least 12 times faster than the SSInClk. In slave legacy mode, the maximum frequency of SSInClk is 10 MHz. See “Synchronous Serial Interface (SSI)” on page 1867 to view legacy SSI and QSSI timing parameters. 17.3.2 FIFO Operation 17.3.2.1 Transmit FIFO The common transmit FIFO is a 16-bit wide, 8-locations deep, first-in, first-out memory buffer. The CPU writes data to the FIFO by writing the SSI Data (SSIDR) register (see page 1249), and data is stored in the FIFO until it is read out by the transmission logic. When configured as a master or a slave, parallel data is written into the transmit FIFO prior to a legacy SSI serial conversion and transmission to the attached slave or master, respectively, through the SSInDAT0/SSInTX pin. In slave mode, the legacy SSI transmits data each time the master initiates a transaction. If the transmit FIFO is empty and the master initiates, the slave transmits the 8th most recent value in the transmit FIFO. If less than 8 values have been written to the transmit FIFO since the SSI module clock was enabled using the Rn bit in the RCGCSSI register or if the QSSI is reset using the SRSSI register, then 0 is transmitted. Care should be taken to ensure that valid data is in the FIFO as needed. The QSSI can be configured to generate an interrupt or a µDMA request when the FIFO is empty. Note: 17.3.2.2 When operating in Legacy Mode, the QuadSSI's SSInXDAT0 signal functions as SSInTX. Receive FIFO The common receive FIFO is a 16-bit wide, 8-locations deep, first-in, first-out memory buffer. Received data using the legacy serial interface is stored in the buffer until read out by the CPU, which accesses the read FIFO by reading the SSIDR register. If the receive FIFO is full when the master or slave receives new data, the data is held off until the receive FIFO has space. June 18, 2014 1229 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) The SSI only provides an SSIClk while transmitting data. When receiving data in master mode, a dummy write to the SSIDR register must be performed before any read so that the SSIClk can be properly received by the slave and allow data to be sent to the receive FIFO of the master. When configured as a master or slave, serial data received through the SSInDAT1/SSInRX pin is registered prior to parallel loading into the attached slave or master receive FIFO, respectively. Note: 17.3.3 When operating in Legacy Mode, the QSSI's SSInXDAT1 signal functions as SSInRX. Advanced, Bi- and Quad- SSI Function Bi-SSI uses two data pins, SSInXDAT0 and SSInXDAT1, that can be configured to receive or transmit data. In Quad-SSI mode, SSInXDAT0, SSInXDAT1, SSInXDAT2 and SSInXDAT3 allow four bits of data to be received or transmitted at once. Note that in bi- and quad-SSI data transfers are only half-duplex. By programming the MODE bits in the SSICR1 register, Advanced, Bi- or Quad- SSI can be enabled. A direction bit, DIR, is provided to program the direction of operation during a Bi- or Quad SSItransaction. Since Bi- and Quad-SSI cannot be full duplex, the DIR bit defines whether or not the RX FIFO is disabled. In Advanced operation, if the QSSI module TX (write) mode is enabled, the RX FIFO is automatically prevented from receiving any data. When Advanced SSI is in RX (read) mode, it operates as a full-duplex interface. In Bi- and Quad-SSI mode, because only 8-bit data is allowed, the DSS bit field must be programmed to 0x7 in the SSICR0 register before transferring data to the Rx and TX FIFOs. For a data transmit, the 8-bit data packet is placed in a TX FIFO entry bits [7:0] and the mode of operation is inserted in the three most significant bits of the TX FIFO entry. The mode of operation bits [15:13] in the TX FIFO are used by the QSSI module for configuring the data on the proper pins. The following modes that may be placed on bits [15:13] of the FIFO entry are: ■ Bi-SSI mode (0x1) ■ Quad-SSI mode (0x2) ■ Advanced SSI mode (0x3) When data is first written to the TX FIFO, a SSInFss is asserted low indicating the start of a frame. At the end of transmission, bit 12 of the last data entry in the TX FIFO signifies whether a a frame is ending. When the EOM bit is 1 it indicates a End of Message (EOM or STOP frame) and SSInFss is subsequently forced high. The EOM bit is cleared in the SSICR1 register on the same clock that the write to TXFIFO is completed. An EOM bit value of 0 indicates no change in transmission. If TX FIFO is emptied and SSInFSS is still asserted low, it remains low but SSInCLK is not pulsed. Likewise, if SSInFss is high when the TX FIFO is empty, it remains high. During a Bi-SSI transmit frame, data is shifted out by two bits and placed on the corresponding two SSInDATn pins. For a Quad-SSI transmit frame data is shifted out by four bits and placed on the corresponding four SSInDATn pins. In Bi-, Quad- and Advanced SSI, the lower byte of the Rx FIFO contains received data. The upper byte contains no valid information. Note: While the master is in Bi- or Quad-SSI mode, if the DSS bit in the SSICR0 register is not set to 0x7, the QSSI module reverts to Legacy mode and behavior is not guaranteed. The SSICRI1 register bits DIR and MODE are used to program what operation is needed for the next data bytes that are being loaded into the FIFO. Table 17-2 on page 1231 shows available modes of operation: 1230 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 17-2. QSSI Transaction Encodings DIR MODE X 0x0 SSI Legacy operation supporting 4 to 16 data bits 0 0x1 Transmit (TX) Bi-SSI with 8-bits of packet data 0 0x2 Transmit (TX) Quad-SSI with 8-bits of packet data 0 0x3 Transmit (TX) Advanced SSI mode with 8-bits of packet data and write RX FIFO disabled 1 0x1 Receive (RX) Bi-SSI with 8-bits of packet data 1 0x2 Receive (RX) Quad-SSI with 8-bits of packet data 1 0x3 Full duplex Advance SSI with 8-bits of packet data Note: Operation SPO = 0 and SPH =0 is the only frame structure allowed for Advanced, Bi- and Quad-mode. Different transactions can follow one another in the FIFOs. The following transaction combinations are allowed: ■ Legacy SSI mode (if configured for this mode, switching to any other alternate mode is not recommended) ■ Advanced SSI mode followed by Bi-SSI mode ■ Advanced SSI mode followed by Quad-SSI mode ■ Advanced SSI mode followed by Bi-SSI mode followed by Advanced SSI mode ■ Advanced SSI mode followed by Quad-SSI mode followed by Advanced SSI mode Note that switching between Quad-SSI and Bi-SSI is not encouraged in a single transaction. 17.3.4 SSInFSS Function For enhanced modes of operation, the SSInFss signal can be programmed to assert low at the start of each byte transfer for one clock or the entire frame. This is configured by programming the FSSHLDFRM bit in the SSICR1 register. The EOM bit is also provided to signify end of frame transmission. This bit is embedded in the TXFIFO entry for use at the interface to deassert SSInFss at the appropriate time. The FSSHLDFRM bit can also be used when operating in 8-bit Legacy SSI mode. The functionality of the FSSHLDFRM bit for both Legacy SSI mode and the enhanced modes are as follows: Table 17-3. SSInFss Functionality Mode FSSHLDFRM Description 0 For Freescale format, with SPH = 0, the SSInFss signal is asserted low between continuous transfers. For SPH = 1, the SSInFss signal is deasserted (high) between continuous transfers. 1 For Freescale format with any SPH value, the SSInFss signal is forced high between continuous transfers; it is asserted low when there is available data in the Tx FIFO; otherwise it is forced high to be ready for a new frame For TI format, the SSInFss signal is deasserted (high) after every data transfer. Legacy Mode June 18, 2014 1231 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Table 17-3. SSInFss Functionality (continued) Mode FSSHLDFRM 0 Advanced/Bi-/Quad1 SSI Mode 17.3.5 Description SSInFss is asserted low after every byte of data New data written to the TX FIFO notifies SSInFss to assert low until the Tx FIFO is empty. High Speed Clock Operation In master mode, QSSI module can enable a high speed clock by setting the HSCLKEN bit in the SSI Control 1 (SSICR1) register. In this mode of operation, SSInCLK from the QSSI master operation is reflected back as a loopback clock, HSPEEDCLK, to the QSSI module. This allows faster timing since the logic can can be used to adjust clock to external data relationships. HSPEEDCLK captures RX data in a separate register . This allows the time between the clock as seen by a remote device and the internal clock to match more closely. Receive data is captured in a separate register sampled on loop-back clock (HSPEEDCLK) and the RX FIFO write control registered on HSPEEDCLK. If the HSCKEN = 1, the corresponding shift register and FIFO write enable will be selected for use. This supports faster QSSI master speed. Note: 17.3.6 For proper functionality of high speed mode, the HSCLKEN bit in the SSICR1 register should be set before any SSI data transfer or after applying a reset to the QSSI module. In addition, the SSE bit must be set to 0x1 before the HSCLKEN bit is set. Interrupts The QSSI can generate interrupts when the following conditions are observed: ■ Transmit FIFO service (when the transmit FIFO is half full or less) ■ Receive FIFO service (when the receive FIFO is half full or more) ■ Receive FIFO time-out ■ Receive FIFO overrun ■ End of transmission ■ Receive DMA transfer complete ■ Transmit DMA transfer complete All of the interrupt events are ORed together before being sent to the interrupt controller, so the QSSI generates a single interrupt request to the controller regardless of the number of active interrupts. Each of the seven individual maskable interrupts can be masked by clearing the appropriate bit in the SSI Interrupt Mask (SSIIM) register (see page 1253). Setting the appropriate mask bit enables the interrupt. The individual outputs, along with a combined interrupt output, allow use of either a global interrupt service routine or modular device drivers to handle interrupts. The transmit and receive dynamic dataflow interrupts have been separated from the status interrupts so that data can be read or written in response to the FIFO trigger levels. The status of the individual interrupt sources can be read from the SSI Raw Interrupt Status (SSIRIS) and SSI Masked Interrupt Status (SSIMIS) registers (see page 1255 and page 1257, respectively). The RX FIFO has an associated time-out counter which starts to down count at the same time the RX FIFO is flagged as not empty by the RNE bit in the SSISR register. The counter is reset any time 1232 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller a new or next byte is written to the RX FIFO, thus the counter will continue to count down to zero unless there is new activity. The time-out period is 32 periods based on the period of SSInClk. When the counter reaches zero, a time-out interrupt bit, RTRIS, is set in the SSIRIS register. The time-out interrupt can be cleared by writing a 1 to the RTIC bit of the SSI Interrupt Clear (SSIIC) register or by emptying the RX FIFO. If the interrupt is cleared and there is residual data left in the RX FIFO or new data entries have been written, the timer count down initiates and the interrupt will be reasserted after 32 periods have been counted. The End-of-Transmission (EOT) interrupt indicates that the data has been transmitted completely and is only valid for Master mode devices/operations. This interrupt can be used to indicate when it is safe to turn off the QSSI module clock or enter sleep mode. In addition, because transmitted data and received data complete at exactly the same time, the interrupt can also indicate that read data is ready immediately, without waiting for the receive FIFO time-out period to complete. Note: 17.3.7 In Freescale SPI mode only, a condition can be created where an EOT interrupt is generated for every byte transferred even if the FIFO is full. If the the µDMA has been configured to transfer data from this QSSI to a Master QSSI on the device using external loopback, an EOT interrupt is generated by the QSSI slave for every byte even if the FIFO is full. Frame Formats Each data frame is between 4 and 16 bits long in Legacy mode and 8-bits in Advanced/Bi-/QuadSSI mode and is transmitted starting with the MSB. There are two basic frame types that can be selected by programming the FRF bit in the SSICR0 register: ■ Texas Instruments synchronous serial ■ Freescale SPI Note: Advanced, Bi- and Quad-SSI modules only supports Freescale mode when SPH=0; SPO=0 and DDS=0x8 in the SSI Control 0 (SSICR0) register. For both formats, the serial clock (SSInClk) is held inactive while the QSSI is idle, and SSInClk transitions at the programmed frequency only during active transmission or reception of data. The idle state of SSInClk is utilized to provide a receive timeout indication that occurs when the receive FIFO still contains data after a timeout period. For Freescale SPI frame format, the serial frame (SSInFss) pin is active Low, and is asserted (pulled down) during the entire transmission of the frame. For Texas Instruments synchronous serial frame format, the SSInFss pin is pulsed for one serial clock period starting at its rising edge, prior to the transmission of each frame. For this frame format, both the QSSI and the off-chip slave device drive their output data on the rising edge of SSInClk and latch data from the other device on the falling edge. The following table gives a synopsis of the features supported in each frame format when operating in Legacy Mode: Table 17-4. Legacy Mode TI, Freescale SPI Frame Format Features Feature TI Mode Freescale SPI Mode Frame Hold Not Available Available High Speed (Master RX Only) Not Available Available SPO/SPH Configuration Not Available Available and can be used in combination with Frame Hold and High Speed Mode June 18, 2014 1233 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Table 17-4. Legacy Mode TI, Freescale SPI Frame Format Features (continued) Feature TI Mode Frequency (system clock : SSInCLK) Freescale SPI Mode Master 1:2 Master 1:2 Slave 1:12 Slave 1:12 For Advanced, Bi- and Quad-SSI modes using the Freescale SPI Format or the Bi- and Quad-SSI modes using the TI format, the following features are supported: ■ Frame Hold ■ High Speed (Master RX Only) ■ SPO/SPH Configuration with SPO=0 and SPH=0 only allowed ■ Frequency (system clock : SSInCLK): – Master 1:2 – Slave 1:12 17.3.7.1 Texas Instruments Synchronous Serial Frame Format Figure 17-2 on page 1234 shows the Texas Instruments synchronous serial frame format for a single transmitted frame. Figure 17-2. TI Synchronous Serial Frame Format (Single Transfer) SSInClk SSInFss SSInTx/SSInRx MSB LSB 4 to 16 bits In this mode, SSInClk and SSInFss are forced Low, and the transmit data line SSInDAT0/SSInTX is tristated whenever the QSSI is idle. Once the bottom entry of the transmit FIFO contains data, SSInFss is pulsed High for one SSInClk period. The value to be transmitted is also transferred from the transmit FIFO to the serial shift register of the transmit logic. On the next rising edge of SSInClk, the MSB of the 4 to 16-bit data frame is shifted out on the SSInDAT0/SSInTX pin. Likewise, the MSB of the received data is shifted onto the SSInDAT1/SSInRX pin by the off-chip serial slave device. Both the QSSI and the off-chip serial slave device then clock each data bit into their serial shifter on each falling edge of SSInClk. The received data is transferred from the serial shifter to the receive FIFO on the first rising edge of SSInClk after the LSB has been latched. Figure 17-3 on page 1235 shows the Texas Instruments synchronous serial frame format when back-to-back frames are transmitted. 1234 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 17-3. TI Synchronous Serial Frame Format (Continuous Transfer) SSInClk SSInFss SSInTx/SSInRx MSB LSB 4 to 16 bits 17.3.7.2 Freescale SPI Frame Format The Freescale SPI interface is a four-wire interface where the SSInFss signal behaves as a slave select. If operating in Legacy Mode and using the Freescale SPI Frame Format, the inactive state and phase of the SSInClk signal are programmable through the SPO and SPH bits in the SSICR0 control register. If operating in Advanced/Bi-/Quad-SSI mode, the SP0 and SPH bits must be programmed to 0. SPO Clock Polarity Bit When the SPO clock polarity control bit is clear, it produces a steady state Low value on the SSInClk pin. If the SPO bit is set, a steady state High value is placed on the SSInClk pin when data is not being transferred. SPH Phase Control Bit The SPH phase control bit selects the clock edge that captures data and allows it to change state. The state of this bit has the most impact on the first bit transmitted by either allowing or not allowing a clock transition before the first data capture edge. When the SPH phase control bit is clear, data is captured on the first clock edge transition. If the SPH bit is set, data is captured on the second clock edge transition. 17.3.7.3 Freescale SPI Frame Format with SPO=0 and SPH=0 Single and continuous transmission signal sequences for Freescale SPI format with SPO=0 and SPH=0 are shown in Figure 17-4 on page 1236 and Figure 17-5 on page 1236. Note: This is the only Freescale SPI frame format configuration that can be used when operating in Advanced/Bi-/Quad-SSI mode. June 18, 2014 1235 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Figure 17-4. Freescale SPI Format (Single Transfer) with SPO=0 and SPH=0 SSInClk SSInFss SSInRx LSB MSB Q 4 to 16 bits SSInTx MSB Note: LSB Q is undefined. Figure 17-5. Freescale SPI Format (Continuous Transfer) with SPO=0 and SPH=0 SSInClk SSInFss SSInRx LSB LSB MSB MSB 4 to16 bits SSInTx LSB MSB LSB MSB In this configuration, during idle periods: ■ SSInClk is forced Low ■ SSInFss is forced High ■ The transmit data line SSInDAT0/SSInTX is tristated ■ When the QSSI is configured as a master, it enables the SSInClk pad ■ When the QSSI is configured as a slave, it disables the SSInClk pad If the QSSI is enabled and valid data is in the transmit FIFO, the start of transmission is signified by the SSInFss master signal being driven Low, causing slave data to be enabled onto the SSInDAT1/SSInRX input line of the master. The master SSInDAT0/SSInTX output pad is enabled. One half SSInClk period later, valid master data is transferred to the SSInDAT0/SSInTX pin. Once both the master and slave data have been set, the SSInClk master clock pin goes High after one additional half SSInClk period. The data is now captured on the rising and propagated on the falling edges of the SSInClk signal. 1236 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller In the case of a single word transmission, after all bits of the data word have been transferred, the SSInFss line is returned to its idle High state one SSInClk period after the last bit has been captured. However, in the case of continuous back-to-back transmissions, the SSInFss signal must be pulsed High between each data word transfer because the slave select pin freezes the data in its serial peripheral register and does not allow it to be altered if the SPH bit is clear. Therefore, the master device must raise the SSInFss pin of the slave device between each data transfer to enable the serial peripheral data write. On completion of the continuous transfer, the SSInFss pin is returned to its idle state one SSInClk period after the last bit has been captured. 17.3.7.4 Freescale SPI Frame Format with SPO=0 and SPH=1 The transfer signal sequence for Freescale SPI format with SPO=0 and SPH=1 is shown in Figure 17-6 on page 1237, which covers both single and continuous transfers. Note: This Freescale SPI frame format configuration is only available when operating in Legacy SSI mode of operation. Figure 17-6. Freescale SPI Frame Format with SPO=0 and SPH=1 SSInClk SSInFss SSInRx Q Q MSB LSB Q 4 to 16 bits SSInTx LSB MSB Note: Q is undefined. In this configuration, during idle periods: ■ SSInClk is forced Low ■ SSInFss is forced High ■ The transmit data line SSInDAT0/SSInTX is tristated ■ When the QSSI is configured as a master, it enables the SSInClk pad ■ When the QSSI is configured as a slave, it disables the SSInClk pad If the QSSI is enabled and valid data is in the transmit FIFO, the start of transmission is signified by the SSInFss master signal being driven Low. The master SSInDAT0/SSInTX output is enabled. After an additional one-half SSInClk period, both master and slave valid data are enabled onto their respective transmission lines. At the same time, the SSInClk is enabled with a rising edge transition. Data is then captured on the falling edges and propagated on the rising edges of the SSInClk signal. June 18, 2014 1237 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) In the case of a single word transfer, after all bits have been transferred, the SSInFss line is returned to its idle High state one SSInClk period after the last bit has been captured. For continuous back-to-back transfers, the SSInFss pin is held Low between successive data words, and termination is the same as that of the single word transfer. 17.3.7.5 Freescale SPI Frame Format with SPO=1 and SPH=0 Single and continuous transmission signal sequences for Freescale SPI format with SPO=1 and SPH=0 are shown in Figure 17-7 on page 1238 and Figure 17-8 on page 1238. Note: This Freescale SPI frame format configuration is only available when operating in Legacy SSI mode of operation. Figure 17-7. Freescale SPI Frame Format (Single Transfer) with SPO=1 and SPH=0 SSInClk SSInFss SSInRx MSB LSB Q 4 to 16 bits SSInTx LSB MSB Note: Q is undefined. Figure 17-8. Freescale SPI Frame Format (Continuous Transfer) with SPO=1 and SPH=0 SSInClk SSInFss SSInTx/SSInRx LSB MSB LSB MSB 4 to 16 bits In this configuration, during idle periods: ■ SSInClk is forced High ■ SSInFss is forced High ■ The transmit data line SSInDAT0/SSInTX is tristated ■ When the QSSI is configured as a master, it enables the SSInClk pad ■ When the QSSI is configured as a slave, it disables the SSInClk pad 1238 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller If the QSSI is enabled and valid data is in the transmit FIFO, the start of transmission is signified by the SSInFss master signal being driven Low, causing slave data to be immediately transferred onto the SSInDAT1/SSInRX line of the master. The master SSInDAT0/SSInTX output pad is enabled. One-half period later, valid master data is transferred to the SSInDAT0/SSInTX line. Once both the master and slave data have been set, the SSInClk master clock pin becomes Low after one additional half SSInClk period, meaning that data is captured on the falling edges and propagated on the rising edges of the SSInClk signal. In the case of a single word transmission, after all bits of the data word are transferred, the SSInFss line is returned to its idle High state one SSInClk period after the last bit has been captured. However, in the case of continuous back-to-back transmissions, the SSInFss signal must be pulsed High between each data word transfer because the slave select pin freezes the data in its serial peripheral register and does not allow it to be altered if the SPH bit is clear. Therefore, the master device must raise the SSInFss pin of the slave device between each data transfer to enable the serial peripheral data write. On completion of the continuous transfer, the SSInFss pin is returned to its idle state one SSInClk period after the last bit has been captured. 17.3.7.6 Freescale SPI Frame Format with SPO=1 and SPH=1 The transfer signal sequence for Freescale SPI format with SPO=1 and SPH=1 is shown in Figure 17-9 on page 1239, which covers both single and continuous transfers. Note: This Freescale SPI frame format configuration is only available when operating in Legacy SSI mode of operation. Figure 17-9. Freescale SPI Frame Format with SPO=1 and SPH=1 SSInClk SSInFss SSInRx Q MSB LSB Q 4 to 16 bits MSB SSInTx Note: LSB Q is undefined. In this configuration, during idle periods: ■ SSInClk is forced High ■ SSInFss is forced High ■ The transmit data line SSInDAT0/SSInTX is tristated ■ When the QSSI is configured as a master, it enables the SSInClk pad ■ When the QSSI is configured as a slave, it disables the SSInClk pad June 18, 2014 1239 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) If the QSSI is enabled and valid data is in the transmit FIFO, the start of transmission is signified by the SSInFss master signal being driven Low. The master SSInDAT0/SSInTX output pad is enabled. After an additional one-half SSInClk period, both master and slave data are enabled onto their respective transmission lines. At the same time, SSInClk is enabled with a falling edge transition. Data is then captured on the rising edges and propagated on the falling edges of the SSInClk signal. After all bits have been transferred, in the case of a single word transmission, the SSInFss line is returned to its idle high state one SSInClk period after the last bit has been captured. For continuous back-to-back transmissions, the SSInFss pin remains in its active Low state until the final bit of the last word has been captured and then returns to its idle state as described above. For continuous back-to-back transfers, the SSInFss pin is held Low between successive data words and termination is the same as that of the single word transfer. 17.3.8 DMA Operation The QSSI peripheral provides an interface to the μDMA controller with separate channels for transmit and receive. The µDMA operation of the QSSI is enabled through the SSI DMA Control (SSIDMACTL) register. When µDMA operation is enabled, the QSSI asserts a µDMA request on the receive or transmit channel when the associated FIFO can transfer data. For the receive channel, a single transfer request is asserted whenever any data is in the receive FIFO. A burst transfer request is asserted whenever the amount of data in the receive FIFO is 4 or more items. For the transmit channel, a single transfer request is asserted whenever at least one empty location is in the transmit FIFO. The burst request is asserted whenever the transmit FIFO has 4 or more empty slots. The single and burst µDMA transfer requests are handled automatically by the μDMA controller depending how the µDMA channel is configured. To enable µDMA operation for the receive channel, the RXDMAE bit of the DMA Control (SSIDMACTL) register should be set after configuring the µDMA. To enable µDMA operation for the transmit channel, the TXDMAE bit of SSIDMACTL should be set after configuring the µDMA. If the µDMA is enabled and has completed a data transfer from the Tx FIFO, the DMATXRIS bit is set in the SSIRIS register and cannot be cleared by setting the DMATXIC bit in the SSI Interrupt Clear (SSIICR) register. In the DMA Completion Interrupt Service Routine, software must disable the µDMA transmit enable to the SSI by clearing the TXDMAE bit in the QSSI DMA Control (SSIDMACTL) register and then setting the DMATXIC bit in the SSIICR register. This clears the DMA completion interrupt. When the µDMA is needed to transmit more data, the TXDMAE bit must be set (enabled) again. If a data transfer by the µDMA from the Rx FIFO completes, the DMARXRIS bit is set. The EOT bit in the SSIRIS register is also provided to indicate when the Tx FIFO is empty and the last bit has been transmitted out of the serializer Note: Wait states are inserted at every byte transfer when using Bi- or Quad-SSI modes as a master with the μDMA at SSICLK frequencies greater than 1/6 of the system clock. These wait states are because of arbitration stall cycles from the μDMA accesses to SRAM and increased output throughput from the SSI. See “Micro Direct Memory Access (μDMA)” on page 678 for more details about programming the μDMA controller. 17.4 Initialization and Configuration To enable and initialize the QSSI, the following steps are necessary: 1240 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 1. Enable the QSSI module using the RCGCSSI register (see page 390). 2. Enable the clock to the appropriate GPIO module via the RCGCGPIO register (see page 382). To find out which GPIO port to enable, refer to Table 26-5 on page 1808. 3. Set the GPIO AFSEL bits for the appropriate pins (see page 770). To determine which GPIOs to configure, see Table 26-4 on page 1797. 4. Configure the PMCn fields in the GPIOPCTL register to assign the QSSI signals to the appropriate pins. See page 787 and Table 26-5 on page 1808. 5. Program the GPIODEN register to enable the pin's digital function. In addition, the drive strength, drain select and pull-up/pull-down functions must be configured. Refer to “General-Purpose Input/Outputs (GPIOs)” on page 742 for more information. Note: Pull-ups can be used to avoid unnecessary toggles on the QSSI pins, which can take the slave to a wrong state. In addition, if the SSIClk signal is programmed to steady state High through the SPO bit in the SSICR0 register, then software must also configure the GPIO port pin corresponding to the SSInClk signal as a pull-up in the GPIO Pull-Up Select (GPIOPUR) register. For each of the frame formats, the QSSI is configured using the following steps: 1. If initializing out of reset, ensure that the SSE bit in the SSICR1 register is clear before making any configuration changes. Otherwise, configuration changes for Advanced SSI can be made while the SSE bit is set. 2. Select whether the QSSI is a master or slave: a. For master operations, set the SSICR1 register to 0x0000.0000. b. For slave mode (output enabled), set the SSICR1 register to 0x0000.0004. c. For slave mode (output disabled), set the SSICR1 register to 0x0000.000C. 3. Configure the QSSI clock source by writing to the SSICC register. 4. Configure the clock prescale divisor by writing the SSICPSR register. 5. Write the SSICR0 register with the following configuration: ■ Serial clock rate (SCR) ■ Desired clock phase/polarity, if using Freescale SPI mode (SPH and SPO) ■ The protocol mode: Freescale SPI or TI SSF ■ The data size (DSS) 6. Optionally, configure the SSI module for μDMA use with the following steps: a. Configure a μDMA for SSI use. See “Micro Direct Memory Access (μDMA)” on page 678 for more information. b. Enable the SSI Module's TX FIFO or RX FIFO by setting the TXDMAE or RXDMAE bit in the SSIDMACTL register. June 18, 2014 1241 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) c. Optionally, enable the µDMA completion interrupt by setting the DMATXIM or DMARXIM bit in the SSIIM register. Note: For a TX DMA completion interrupt, software must disable the µDMA transmit enable to the SSI by clearing the TXDMAE bit in the QSSI DMA Control (SSIDMACTL) register and then setting the DMATXIC bit in the SSIICR register. This clears the DMA completion interrupt. When the µDMA is needed to transmit more data, the TXDMAE bit must be set (enabled) again. 7. If this is the first initialization out of reset, enable the QSSI by setting the SSE bit in the SSICR1 register. As an example, assume the QSSI must be configured to operate with the following parameters: ■ Master operation ■ Freescale SPI mode (SPO=1, SPH=1) ■ 1 Mbps bit rate ■ 8 data bits Assuming the system clock is 20 MHz, the bit rate calculation would be: SSInClk = SysClk / (CPSDVSR * (1 + SCR)) 1x106 = 20x106 / (CPSDVSR * (1 + SCR)) In this case, if CPSDVSR=0x2, SCR must be 0x9. The configuration sequence would be as follows: 1. Ensure that the SSE bit in the SSICR1 register is clear. 2. Write the SSICR1 register with a value of 0x0000.0000. 3. Write the SSICPSR register with a value of 0x0000.0002. 4. Write the SSICR0 register with a value of 0x0000.09C7. 5. The QSSI is then enabled by setting the SSE bit in the SSICR1 register. 17.4.1 Enhanced Mode Configuration If the QSSI module supports the Advanced/Bi-/Quad features, then these modes can be enabled after initializing the QSSI module. Below is an example of configuring the QSSI to transmit two data bytes in Advanced SSI mode followed by 2 bytes in Bi-SSI mode: 1. Set the MODE bit to 0x3, and the FSSHLDFM bit to 1 in the SSICR1 register. To operate in the master mode, program the MS bit to 0. Program the remaining bits in the SSICR0 and SSICR1 register to relevant values. 2. Write one data byte to the TX FIFO; set the EOM bit to 1 and write the second data byte to the Tx FIFO. 1242 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 3. Set the MODE bit to 0x1 and the FSSHLDFM bit to 1 in the SSICR1 register. To operate in the master mode, program the MS bit to 0. Program the remaining bits in the SSICR0 and SSICR1 register to relevant values. 4. Fill the Tx FIFO with one data byte. 5. Set the EOM bit in the SSICR1 register. 6. Fill the Tx FIFO with one data byte. 17.5 Register Map Table 17-5 on page 1243 lists the QSSI registers. The offset listed is a hexadecimal increment to the register’s address, relative to that QSSI module’s base address: ■ ■ ■ ■ QSSI0: 0x4000.8000 QSSI1: 0x4000.9000 QSSI2: 0x4000.A000 QSSI3: 0x4000.B000 Note that the QSSI module clock must be enabled before the registers can be programmed (see page 390). The Rn bit of the PRSSI register must be read as 0x1 before any QSSI module registers are accessed. Table 17-5. SSI Register Map Description See page 0x0000.0000 QSSI Control 0 1245 RW 0x0000.0000 QSSI Control 1 1247 SSIDR RW 0x0000.0000 QSSI Data 1249 0x00C SSISR RO 0x0000.0003 QSSI Status 1250 0x010 SSICPSR RW 0x0000.0000 QSSI Clock Prescale 1252 0x014 SSIIM RW 0x0000.0000 QSSI Interrupt Mask 1253 0x018 SSIRIS RO 0x0000.0008 QSSI Raw Interrupt Status 1255 0x01C SSIMIS RO 0x0000.0000 QSSI Masked Interrupt Status 1257 0x020 SSIICR W1C 0x0000.0000 QSSI Interrupt Clear 1259 0x024 SSIDMACTL RW 0x0000.0000 QSSI DMA Control 1260 0xFC0 SSIPP RO 0x0000.000D QSSI Peripheral Properties 1261 0xFC8 SSICC RW 0x0000.0000 QSSI Clock Configuration 1262 0xFD0 SSIPeriphID4 RO 0x0000.0000 QSSI Peripheral Identification 4 1263 0xFD4 SSIPeriphID5 RO 0x0000.0000 QSSI Peripheral Identification 5 1264 0xFD8 SSIPeriphID6 RO 0x0000.0000 QSSI Peripheral Identification 6 1265 0xFDC SSIPeriphID7 RO 0x0000.0000 QSSI Peripheral Identification 7 1266 0xFE0 SSIPeriphID0 RO 0x0000.0022 QSSI Peripheral Identification 0 1267 Offset Name Type Reset 0x000 SSICR0 RW 0x004 SSICR1 0x008 June 18, 2014 1243 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Table 17-5. SSI Register Map (continued) Description See page 0x0000.0000 QSSI Peripheral Identification 1 1268 RO 0x0000.0018 QSSI Peripheral Identification 2 1269 SSIPeriphID3 RO 0x0000.0001 QSSI Peripheral Identification 3 1270 0xFF0 SSIPCellID0 RO 0x0000.000D QSSI PrimeCell Identification 0 1271 0xFF4 SSIPCellID1 RO 0x0000.00F0 QSSI PrimeCell Identification 1 1272 0xFF8 SSIPCellID2 RO 0x0000.0005 QSSI PrimeCell Identification 2 1273 0xFFC SSIPCellID3 RO 0x0000.00B1 QSSI PrimeCell Identification 3 1274 Offset Name Type Reset 0xFE4 SSIPeriphID1 RO 0xFE8 SSIPeriphID2 0xFEC 17.6 Register Descriptions The remainder of this section lists and describes the QSSI registers, in numerical order by address offset. 1244 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: QSSI Control 0 (SSICR0), offset 0x000 The SSICR0 register contains bit fields that control various functions within the QSSI module. Functionality such as protocol mode, clock rate, and data size are configured in this register. QSSI Control 0 (SSICR0) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 RO 0 RO 0 RO 0 RO 0 11 10 9 8 SCR Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15:8 SCR RW 0x00 RW 0 RO 0 7 6 SPH SPO RW 0 RW 0 FRF RW 0 DSS RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Serial Clock Rate This bit field is used to generate the transmit and receive bit rate of the QSSI. The bit rate is: BR=SysClk/(CPSDVSR * (1 + SCR)) where CPSDVSR is an even value from 2-254 programmed in the SSICPSR register, and SCR is a value from 0-255. 7 SPH RW 0 QSSI Serial Clock Phase This bit is only applicable to the Freescale SPI Format. The SPH control bit selects the clock edge that captures data and allows it to change state. This bit has the most impact on the first bit transmitted by either allowing or not allowing a clock transition before the first data capture edge. Value Description 6 SPO RW 0 0 Data is captured on the first clock edge transition. 1 Data is captured on the second clock edge transition. QSSI Serial Clock Polarity Value Description 0 A steady state Low value is placed on the SSInClk pin. 1 A steady state High value is placed on the SSInClk pin when data is not being transferred. Note: If this bit is set, then software must also configure the GPIO port pin corresponding to the SSInClk signal as a pull-up in the GPIO Pull-Up Select (GPIOPUR) register. June 18, 2014 1245 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Bit/Field Name Type Reset 5:4 FRF RW 0x0 Description QSSI Frame Format Select Note: When operating in Advanced/Bi-/Quad-SSI mode these bits must be programmed to 0x0 (Freescale SPI Frame Format). Value Frame Format 0x0 Freescale SPI Frame Format 0x1 Texas Instruments Synchronous Serial Frame Format 0x2-0x3 Reserved 3:0 DSS RW 0x0 QSSI Data Size Select Note: When operating in Advanced, Bi- or Quad-SSI, data size can only be 8-bit. All other fields will be ignored. Value Data Size 0x0-0x2 Reserved 0x3 4-bit data 0x4 5-bit data 0x5 6-bit data 0x6 7-bit data 0x7 8-bit data 0x8 9-bit data 0x9 10-bit data 0xA 11-bit data 0xB 12-bit data 0xC 13-bit data 0xD 14-bit data 0xE 15-bit data 0xF 16-bit data 1246 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: QSSI Control 1 (SSICR1), offset 0x004 The SSICR1 register contains bit fields that control various functions within the QSSI module. Master and slave mode functionality is controlled by this register. QSSI Control 1 (SSICR1) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x004 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 11 10 9 8 EOM FSSHLDFRM HSCLKEN DIR RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 11 EOM RW 0 MODE RW 0 reserved RW 0 RO 0 RO 0 RO 0 2 1 0 MS SSE LBM RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Stop Frame (End of Message) This bit is applicable when MODE is set to Advanced, Bi- or Quad- SSI. This bit is inserted into bit 12 of the TXFIFO data entry by the QSSI module. Value Description 10 FSSHLDFRM RW 0 0 No change is transmission status. 1 End of message (Stop Frame). FSS Hold Frame Value Description 9 HSCLKEN RW 0 0 Pulse SSInFss at every byte (the DSS bit in the SSICR0 register must be set to 0x7 (data size 8 bits) in this configuration) 1 Hold SSInFss for the whole frame High Speed Clock Enable High speed clock enable is available only when operating as a master. Value Description 0 Use Input Clock 1 Use High Speed Clock Note: For proper functionality of high speed mode, the HSCLKEN bit in the SSICR1 register should be set before any SSI data transfer or after applying a reset to the QSSI module. In addition, the SSE bit must be set to 0x1 before the HSCLKEN bit is set. June 18, 2014 1247 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Bit/Field Name Type Reset 8 DIR RW 0 Description QSSI Direction of Operation Value Description 7:6 MODE RW 0x0 0 TX (Transmit Mode) write direction 1 RX (Receive Mode) read direction QSSI Mode Value Description 0x0 Legacy SSI mode 0x1 Bi-SSI mode 0x2 Quad-SSI Mode 0x3 Advanced SSI Mode with 8-bit packet size 5:3 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 MS RW 0 QSSI Master/Slave Select This bit selects Master or Slave mode and can be modified only when the QSSI is disabled (SSE=0). Value Description 1 SSE RW 0 0 The QSSI is configured as a master. 1 The QSSI is configured as a slave. QSSI Synchronous Serial Port Enable Value Description 0 QSSI operation is disabled. 1 QSSI operation is enabled. Note: 0 LBM RW 0 The HSCLKEN bit in the SSICR1 register should be set only after applying reset to the QSSI module and enabling the QSSI by setting the SSE bit, and before any SSI data transfer. All other bits in the SSICR1 register and all bits in SSICR0 register can only be programmed when the SSE is clear. QSSI Loopback Mode Value Description 0 Normal serial port operation enabled. 1 Output of the transmit serial shift register is connected internally to the input of the receive serial shift register. 1248 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: QSSI Data (SSIDR), offset 0x008 Important: This register is read-sensitive. See the register description for details. The SSIDR register is 16-bits wide. When the SSIDR register is read, the entry in the receive FIFO that is pointed to by the current FIFO read pointer is accessed. When a data value is removed by the QSSI receive logic from the incoming data frame, it is placed into the entry in the receive FIFO pointed to by the current FIFO write pointer. When the SSIDR register is written to, the entry in the transmit FIFO that is pointed to by the write pointer is written to. Data values are removed from the transmit FIFO one value at a time by the transmit logic. Each data value is loaded into the transmit serial shifter, then serially shifted out onto the SSInDAT0/SSInTX pin at the programmed bit rate. When a data size of less than 16 bits is selected, the user must right-justify data written to the transmit FIFO. The transmit logic ignores the unused bits. Received data less than 16 bits is automatically right-justified in the receive buffer. QSSI Data (SSIDR) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset DATA Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 DATA RW 0x0000 QSSI Receive/Transmit Data A read operation reads the receive FIFO. A write operation writes the transmit FIFO. Software must right-justify data when the QSSI is programmed for a data size that is less than 16 bits. Unused bits at the top are ignored by the transmit logic. The receive logic automatically right-justifies the data. June 18, 2014 1249 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 4: QSSI Status (SSISR), offset 0x00C The SSISR register contains bits that indicate the FIFO fill status and the QSSI busy status. QSSI Status (SSISR) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x00C Type RO, reset 0x0000.0003 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 10 9 8 7 6 5 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:5 reserved RO 0x0000.00 4 BSY RO 0 RO 0 RO 0 RO 0 RO 0 4 3 2 1 0 BSY RFF RNE TNF TFE RO 0 RO 0 RO 0 RO 1 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Busy Bit Value Description 3 RFF RO 0 0 The QSSI is idle. 1 The QSSI is currently transmitting and/or receiving a frame, or the transmit FIFO is not empty. QSSI Receive FIFO Full Value Description 2 RNE RO 0 0 The receive FIFO is not full. 1 The receive FIFO is full. QSSI Receive FIFO Not Empty Value Description 1 TNF RO 1 0 The receive FIFO is empty. 1 The receive FIFO is not empty. QSSI Transmit FIFO Not Full Value Description 0 The transmit FIFO is full. 1 The transmit FIFO is not full. 1250 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 TFE RO 1 Description QSSI Transmit FIFO Empty Value Description 0 The transmit FIFO is not empty. 1 The transmit FIFO is empty. June 18, 2014 1251 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 5: QSSI Clock Prescale (SSICPSR), offset 0x010 The SSICPSR register specifies the division factor which is used to derive the SSInClk from the system clock. The clock is further divided by a value from 1 to 256, which is 1 + SCR. SCR is programmed in the SSICR0 register. The frequency of the SSInClk is defined by: SSInClk = SysClk / (CPSDVSR * (1 + SCR)) The value programmed into this register must be an even number between 2 and 254. The least-significant bit of the programmed number is hard-coded to zero. If an odd number is written to this register, data read back from this register has the least-significant bit as zero. QSSI Clock Prescale (SSICPSR) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset CPSDVSR RO 0 RW 0 Bit/Field Name Type Reset Description 31:8 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7:0 CPSDVSR RW 0x00 QSSI Clock Prescale Divisor This value must be an even number from 2 to 254, depending on the frequency of SSInClk. The LSB always returns 0 on reads. 1252 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 6: QSSI Interrupt Mask (SSIIM), offset 0x014 The SSIIM register is the interrupt mask set or clear register. It is a read/write register and all bits are cleared on reset. On a read, this register gives the current value of the mask on the corresponding interrupt. Setting a bit clears the mask, enabling the interrupt to be sent to the interrupt controller. Clearing a bit sets the corresponding mask, preventing the interrupt from being signaled to the controller. QSSI Interrupt Mask (SSIIM) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x014 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 TXIM RXIM RTIM RORIM RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset EOTIM RO 0 DMATXIM DMARXIM RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:7 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 6 EOTIM RW 0 End of Transmit Interrupt Mask Value Description 5 DMATXIM RW 0 0 The end of transmit interrupt is masked. 1 The end of transmit interrupt is not masked. QSSI Transmit DMA Interrupt Mask Value Description 4 DMARXIM RW 0 0 The transmit DMA interrupt is masked. 1 The transmit DMA interrupt is not masked. QSSI Receive DMA Interrupt Mask Value Description 3 TXIM RW 0 0 The receive DMA interrupt is masked. 1 The receive DMA interrupt is not masked. QSSI Transmit FIFO Interrupt Mask Value Description 0 The transmit FIFO interrupt is masked. 1 The transmit FIFO interrupt is not masked. June 18, 2014 1253 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Bit/Field Name Type Reset 2 RXIM RW 0 Description QSSI Receive FIFO Interrupt Mask Value Description 1 RTIM RW 0 0 The receive FIFO interrupt is masked. 1 The receive FIFO interrupt is not masked. QSSI Receive Time-Out Interrupt Mask Value Description 0 RORIM RW 0 0 The receive FIFO time-out interrupt is masked. 1 The receive FIFO time-out interrupt is not masked. QSSI Receive Overrun Interrupt Mask Value Description 0 The receive FIFO overrun interrupt is masked. 1 The receive FIFO overrun interrupt is not masked. 1254 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 7: QSSI Raw Interrupt Status (SSIRIS), offset 0x018 The SSIRIS register is the raw interrupt status register. On a read, this register gives the current raw status value of the corresponding interrupt prior to masking. A write has no effect. QSSI Raw Interrupt Status (SSIRIS) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x018 Type RO, reset 0x0000.0008 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 reserved Type Reset RO 0 RO 0 RO 0 RO 0 EOTRIS DMATXRIS DMARXRIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 TXRIS RXRIS RTRIS RORRIS RO 1 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:7 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 6 EOTRIS RO 0 End of Transmit Raw Interrupt Status Value Description 0 No interrupt. 1 The transmit FIFO is empty, and the last bit has been transmitted out of the serializer. This bit is cleared when a 1 is written to the EOTIC bit in the SSI Interrupt Clear (SSIICR) register. 5 DMATXRIS RO 0 QSSI Transmit DMA Raw Interrupt Status Value Description 0 No interrupt. 1 The transmit DMA has completed. This bit is cleared when a 1 is written to the DMATXIC bit in the SSI Interrupt Clear (SSIICR) register. 4 DMARXRIS RO 0 QSSI Receive DMA Raw Interrupt Status Value Description 0 No interrupt. 1 The receive DMA has completed. This bit is cleared when a 1 is written to the DMARXIC bit in the SSI Interrupt Clear (SSIICR) register. June 18, 2014 1255 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Bit/Field Name Type Reset 3 TXRIS RO 1 Description QSSI Transmit FIFO Raw Interrupt Status Value Description 0 No interrupt. 1 The transmit FIFO is half empty or less. This bit is cleared when the transmit FIFO is more than half full. 2 RXRIS RO 0 QSSI Receive FIFO Raw Interrupt Status Value Description 0 No interrupt. 1 The receive FIFO is half full or more. This bit is cleared when the receive FIFO is less than half full. 1 RTRIS RO 0 QSSI Receive Time-Out Raw Interrupt Status Value Description 0 No interrupt. 1 The receive time-out has occurred. This bit is cleared when a 1 is written to the RTIC bit in the SSI Interrupt Clear (SSIICR) register. 0 RORRIS RO 0 QSSI Receive Overrun Raw Interrupt Status Value Description 0 No interrupt. 1 The receive FIFO has overflowed This bit is cleared when a 1 is written to the RORIC bit in the SSI Interrupt Clear (SSIICR) register. 1256 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: QSSI Masked Interrupt Status (SSIMIS), offset 0x01C The SSIMIS register is the masked interrupt status register. On a read, this register gives the current masked status value of the corresponding interrupt. A write has no effect. QSSI Masked Interrupt Status (SSIMIS) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x01C Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 reserved Type Reset RO 0 RO 0 RO 0 RO 0 EOTMIS DMATXMIS DMARXMIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 TXMIS RXMIS RTMIS RORMIS RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:7 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 6 EOTMIS RO 0 End of Transmit Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the transmission of the last data bit. This bit is cleared when a 1 is written to the EOTIC bit in the SSI Interrupt Clear (SSIICR) register. 5 DMATXMIS RO 0 QSSI Transmit DMA Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the completion of the transmit DMA. This bit is cleared when a 1 is written to the DMATXIC bit in the SSI Interrupt Clear (SSIICR) register. 4 DMARXMIS RO 0 QSSI Receive DMA Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the completion of the receive DMA. This bit is cleared when a 1 is written to the DMARXIC bit in the SSI Interrupt Clear (SSIICR) register. June 18, 2014 1257 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Bit/Field Name Type Reset 3 TXMIS RO 0 Description QSSI Transmit FIFO Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the transmit FIFO being half empty or less. This bit is cleared when the transmit FIFO is more than half empty . 2 RXMIS RO 0 QSSI Receive FIFO Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the receive FIFO being half full or more. This bit is cleared when the receive FIFO is less than half full. 1 RTMIS RO 0 QSSI Receive Time-Out Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the receive time out. This bit is cleared when a 1 is written to the RTIC bit in the SSI Interrupt Clear (SSIICR) register. 0 RORMIS RO 0 QSSI Receive Overrun Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked interrupt was signaled due to the receive FIFO overflowing. This bit is cleared when a 1 is written to the RORIC bit in the SSI Interrupt Clear (SSIICR) register. 1258 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 9: QSSI Interrupt Clear (SSIICR), offset 0x020 The SSIICR register is the interrupt clear register. On a write of 1, the corresponding interrupt is cleared. A write of 0 has no effect. QSSI Interrupt Clear (SSIICR) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x020 Type W1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 reserved Type Reset RO 0 RO 0 RO 0 RO 0 6 EOTIC RO 0 RO 0 RO 0 RO 0 RO 0 W1C 0 DMATXIC DMARXIC W1C 0 W1C 0 reserved RO 0 RO 0 1 0 RTIC RORIC W1C 0 W1C 0 Bit/Field Name Type Reset Description 31:7 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 6 EOTIC W1C 0 End of Transmit Interrupt Clear Writing a 1 to this bit clears the EOTRIS bit in the SSIRIS register and the EOTMIS bit in the SSIMIS register. 5 DMATXIC W1C 0 QSSI Transmit DMA Interrupt Clear Writing a 1 to this bit clears the DMATXRIS bit in the SSIRIS register and the DMATXMIS bit in the SSIMIS register. 4 DMARXIC W1C 0 QSSI Receive DMA Interrupt Clear Writing a 1 to this bit clears the DMARXRIS bit in the SSIRIS register and the DMARXMIS bit in the SSIMIS register. 3:2 reserved RO 0x0 1 RTIC W1C 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Receive Time-Out Interrupt Clear Writing a 1 to this bit clears the RTRIS bit in the SSIRIS register and the RTMIS bit in the SSIMIS register. 0 RORIC W1C 0 QSSI Receive Overrun Interrupt Clear Writing a 1 to this bit clears the RORRIS bit in the SSIRIS register and the RORMIS bit in the SSIMIS register. June 18, 2014 1259 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 10: QSSI DMA Control (SSIDMACTL), offset 0x024 The SSIDMACTL register is the µDMA control register. QSSI DMA Control (SSIDMACTL) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:2 reserved RO 0x0000.000 1 TXDMAE RW 0 TXDMAE RXDMAE RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Transmit DMA Enable Value Description 0 RXDMAE RW 0 0 µDMA for the transmit FIFO is disabled. 1 µDMA for the transmit FIFO is enabled. Receive DMA Enable Value Description 0 µDMA for the receive FIFO is disabled. 1 µDMA for the receive FIFO is enabled. 1260 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: QSSI Peripheral Properties (SSIPP), offset 0xFC0 The SSIPP register provides information regarding the properties of the QSSI module. QSSI Peripheral Properties (SSIPP) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFC0 Type RO, reset 0x0000.000D 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type 31:4 reserved RO 3 FSSHLDFRM RO RO 0 Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 1 MODE FSSHLDFRM RO 1 0 HSCLK RO 0 RO 1 Description 0x0000.0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x1 SSInFss Hold Frame Capability Value Description 2:1 MODE RO 0x2 0 SSInFss Hold Frame capability disabled. 1 SSinFss Hold Frame capability enabled. Mode of Operation Indicates what QSSI functionality is supported. Value Description 0 HSCLK RO 0x1 0x0 Legacy SSI mode 0x1 Legacy mode, Advanced SSI mode and Bi-SSI mode enabled. 0x2 Legacy mode, Advanced mode, Bi-SSI and Quad-SSI mode enabled. 0x3 reserved High Speed Capability Value Description 0 High Speed clock capability disabled. 1 High speed clock capability enabled. June 18, 2014 1261 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 12: QSSI Clock Configuration (SSICC), offset 0xFC8 The SSICC register controls the baud clock source for the QSSI module. Note: If ALTCLK is used for the QSSI baud clock, the system clock frequency must be at least twice that of the ALTCLK programmed value in Run mode. QSSI Clock Configuration (SSICC) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFC8 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset CS Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 CS RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Baud Clock Source The following table specifies the source that generates for the QSSI baud clock: Value Description 0x0 System clock (based on clock source and divisor factor programmed in RSCLKCFG register in the System Control Module) 0x1-0x4 reserved 0x5 Alternate clock source as defined by ALTCLKCFG register in System Control Module. 0x6 - 0xF Reserved 1262 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 13: QSSI Peripheral Identification 4 (SSIPeriphID4), offset 0xFD0 The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 4 (SSIPeriphID4) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFD0 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID4 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID4 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [7:0] Can be used by software to identify the presence of this peripheral. June 18, 2014 1263 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 14: QSSI Peripheral Identification 5 (SSIPeriphID5), offset 0xFD4 The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 5 (SSIPeriphID5) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFD4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID5 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID5 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [15:8] Can be used by software to identify the presence of this peripheral. 1264 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 15: QSSI Peripheral Identification 6 (SSIPeriphID6), offset 0xFD8 The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 6 (SSIPeriphID6) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFD8 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID6 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID6 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [23:16] Can be used by software to identify the presence of this peripheral. June 18, 2014 1265 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 16: QSSI Peripheral Identification 7 (SSIPeriphID7), offset 0xFDC The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 7 (SSIPeriphID7) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFDC Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID7 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID7 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [31:24] Can be used by software to identify the presence of this peripheral. 1266 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 17: QSSI Peripheral Identification 0 (SSIPeriphID0), offset 0xFE0 The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 0 (SSIPeriphID0) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFE0 Type RO, reset 0x0000.0022 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 1 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID0 RO 0x22 RO 0 RO 0 RO 0 RO 1 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [7:0] Can be used by software to identify the presence of this peripheral. June 18, 2014 1267 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 18: QSSI Peripheral Identification 1 (SSIPeriphID1), offset 0xFE4 The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 1 (SSIPeriphID1) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFE4 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID1 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID1 RO 0x00 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [15:8] Can be used by software to identify the presence of this peripheral. 1268 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: QSSI Peripheral Identification 2 (SSIPeriphID2), offset 0xFE8 The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 2 (SSIPeriphID2) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFE8 Type RO, reset 0x0000.0018 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 1 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID2 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID2 RO 0x18 RO 0 RO 0 RO 0 RO 0 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [23:16] Can be used by software to identify the presence of this peripheral. June 18, 2014 1269 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 20: QSSI Peripheral Identification 3 (SSIPeriphID3), offset 0xFEC The SSIPeriphIDn registers are hard-coded and the fields within the register determine the reset value. QSSI Peripheral Identification 3 (SSIPeriphID3) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFEC Type RO, reset 0x0000.0001 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 PID3 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 PID3 RO 0x01 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI Peripheral ID Register [31:24] Can be used by software to identify the presence of this peripheral. 1270 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 21: QSSI PrimeCell Identification 0 (SSIPCellID0), offset 0xFF0 The SSIPCellIDn registers are hard-coded, and the fields within the register determine the reset value. QSSI PrimeCell Identification 0 (SSIPCellID0) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFF0 Type RO, reset 0x0000.000D 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 1 RO 1 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID0 RO 0x0D RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI PrimeCell ID Register [7:0] Provides software a standard cross-peripheral identification system. June 18, 2014 1271 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 22: QSSI PrimeCell Identification 1 (SSIPCellID1), offset 0xFF4 The SSIPCellIDn registers are hard-coded, and the fields within the register determine the reset value. QSSI PrimeCell Identification 1 (SSIPCellID1) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFF4 Type RO, reset 0x0000.00F0 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID1 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID1 RO 0xF0 RO 0 RO 1 RO 1 RO 1 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI PrimeCell ID Register [15:8] Provides software a standard cross-peripheral identification system. 1272 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 23: QSSI PrimeCell Identification 2 (SSIPCellID2), offset 0xFF8 The SSIPCellIDn registers are hard-coded, and the fields within the register determine the reset value. QSSI PrimeCell Identification 2 (SSIPCellID2) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFF8 Type RO, reset 0x0000.0005 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 1 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID2 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID2 RO 0x05 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI PrimeCell ID Register [23:16] Provides software a standard cross-peripheral identification system. June 18, 2014 1273 Texas Instruments-Production Data Quad Synchronous Serial Interface (QSSI) Register 24: QSSI PrimeCell Identification 3 (SSIPCellID3), offset 0xFFC The SSIPCellIDn registers are hard-coded, and the fields within the register determine the reset value. QSSI PrimeCell Identification 3 (SSIPCellID3) QSSI0 base: 0x4000.8000 QSSI1 base: 0x4000.9000 QSSI2 base: 0x4000.A000 QSSI3 base: 0x4000.B000 Offset 0xFFC Type RO, reset 0x0000.00B1 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CID3 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CID3 RO 0xB1 RO 0 RO 1 RO 0 RO 1 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. QSSI PrimeCell ID Register [31:24] Provides software a standard cross-peripheral identification system. 1274 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 18 Inter-Integrated Circuit (I2C) Interface The Inter-Integrated Circuit (I2C) bus provides bi-directional data transfer through a two-wire design (a serial data line SDA and a serial clock line SCL), and interfaces to external I2C devices such as serial memory (RAMs and ROMs), networking devices, LCDs, tone generators, and so on. The I2C bus may also be used for system testing and diagnostic purposes in product development and manufacturing. The TM4C1294NCPDT microcontroller includes providing the ability to communicate (both transmit and receive) with other I2C devices on the bus. The TM4C1294NCPDT controller includes I2C modules with the following features: ■ Devices on the I2C bus can be designated as either a master or a slave – Supports both transmitting and receiving data as either a master or a slave – Supports simultaneous master and slave operation ■ Four I2C modes – Master transmit – Master receive – Slave transmit – Slave receive ■ Two 8-entry FIFOs for receive and transmit data – FIFOs can be independently assigned to master or slave ■ Four transmission speeds: – Standard (100 Kbps) – Fast-mode (400 Kbps) – Fast-mode plus (1 Mbps) – High-speed mode (3.33 Mbps) ■ Glitch suppression ■ SMBus support through software – Clock low timeout interrupt – Dual slave address capability – Quick command capability ■ Master and slave interrupt generation – Master generates interrupts when a transmit or receive operation completes (or aborts due to an error) June 18, 2014 1275 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface – Slave generates interrupts when data has been transferred or requested by a master or when a START or STOP condition is detected ■ Master with arbitration and clock synchronization, multimaster support, and 7-bit addressing mode ■ Efficient transfers using Micro Direct Memory Access Controller (µDMA) – Separate channels for transmit and receive – Ability to execute single data transfers or burst data transfers using the RX and TX FIFOs in the I2C 18.1 Block Diagram Figure 18-1. I2C Block Diagram dma_done dma_req dma_sreq interrupt Master Core I2CMSA I2CMCS I2CMDR RXFIFO I2CMTPR I2CMIMR Master I2CSDA I2CMRIS I2CMMIS I2CMICR I2CMCR I2CMCLKOCNT TX FIFO Slave I2CSDA Master I2CSCL I2CMBMON I2CMBCNT Master I2CSDA Slave Core Slave I2CSCL I2CMBMLEN I2CSOAR I2CSCSR Slave I2CSDA I2C I/O Select Data I2CSCL I2CSDA I2CSDR I2CSIMR I2C Status and Control I2CSRIS I2CFIFODATA I2CSMIS I2CFIFOCTL I2CSICR I2CFIFOSTATUS I2CSSOAR2 I2CPP I2CSACKCTL 1276 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 18.2 Signal Description The following table lists the external signals of the I2C interface and describes the function of each. The I2C interface signals are alternate functions for some GPIO signals and default to be GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible GPIO pin placements for the I2C signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the I2C function. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the I2C signal to the specified GPIO port pin. Note that the I2CSDA pin should be set to open drain using the GPIO Open Drain Select (GPIOODR) register. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Table 18-1. I2C Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description I2C0SCL 91 PB2 (2) I/O OD I2C module 0 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C0SDA 92 PB3 (2) I/O OD I2C module 0 data. I2C1SCL 49 PG0 (2) I/O OD I2C module 1 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C1SDA 50 PG1 (2) I/O OD I2C module 1 data. I2C2SCL 82 106 112 PL1 (2) PP5 (2) PN5 (3) I/O OD I2C module 2 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C2SDA 81 111 PL0 (2) PN4 (3) I/O OD I2C module 2 data. I2C3SCL 63 PK4 (2) I/O OD I2C module 3 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C3SDA 62 PK5 (2) I/O OD I2C module 3 data. I2C4SCL 61 PK6 (2) I/O OD I2C module 4 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C4SDA 60 PK7 (2) I/O OD I2C module 4 data. I2C5SCL 95 121 PB0 (2) PB4 (2) I/O OD I2C module 5 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C5SDA 96 120 PB1 (2) PB5 (2) I/O OD I2C module 5 data. I2C6SCL 40 PA6 (2) I/O OD I2C module 6 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C6SDA 41 PA7 (2) I/O OD I2C module 6 data. I2C7SCL 1 37 PD0 (2) PA4 (2) I/O OD I2C module 7 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C7SDA 2 38 PD1 (2) PA5 (2) I/O OD I2C module 7 data. June 18, 2014 1277 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Table 18-1. I2C Signals (128TQFP) (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description I2C8SCL 3 35 PD2 (2) PA2 (2) I/O OD I2C module 8 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C8SDA 4 36 PD3 (2) PA3 (2) I/O OD I2C module 8 data. I2C9SCL 33 PA0 (2) I/O OD I2C module 9 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C9SDA 34 PA1 (2) I/O OD I2C module 9 data. 18.3 Functional Description Each I2C module is comprised of both master and slave functions and is identified by a unique address. A master-initiated communication generates the clock signal, SCL. For proper operation, the SDA pin must be configured as an open-drain signal. Due to the internal circuitry that supports high-speed operation, the SCL pin must not be configured as an open-drain signal, although the internal circuitry causes it to act as if it were an open drain signal. Both SDA and SCL signals must be connected to a positive supply voltage using a pull-up resistor. A typical I2C bus configuration is shown in Figure 18-2. Refer to the I2C-bus specification and user manual to determine the size of the pull-ups needed for proper operation. See “Inter-Integrated Circuit (I2C) Interface” on page 1870 for I2C timing diagrams. Figure 18-2. I2C Bus Configuration RPUP SCL SDA I2C Bus I2CSCL I2CSDA Tiva™ Microcontroller 18.3.1 RPUP SCL SDA 3rd Party Device with I2C Interface SCL SDA 3rd Party Device with I2C Interface I2C Bus Functional Overview The I2C bus uses only two signals: SDA and SCL, named I2CSDA and I2CSCL on TM4C1294NCPDT microcontrollers. SDA is the bi-directional serial data line and SCL is the bi-directional serial clock line. The bus is considered idle when both lines are High. Every transaction on the I2C bus is nine bits long, consisting of eight data bits and a single acknowledge bit. The number of bytes per transfer (defined as the time between a valid START and STOP condition, described in “START and STOP Conditions” on page 1279) is unrestricted, but each data byte has to be followed by an acknowledge bit, and data must be transferred MSB first. When a receiver cannot receive another complete byte, it can hold the clock line SCL Low and force the transmitter into a wait state. The data transfer continues when the receiver releases the clock SCL. 1278 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 18.3.1.1 START and STOP Conditions The protocol of the I2C bus defines two states to begin and end a transaction: START and STOP. A High-to-Low transition on the SDA line while the SCL is High is defined as a START condition, and a Low-to-High transition on the SDA line while SCL is High is defined as a STOP condition. The bus is considered busy after a START condition and free after a STOP condition. See Figure 18-3. Figure 18-3. START and STOP Conditions SDA SDA SCL SCL START condition STOP condition The STOP bit determines if the cycle stops at the end of the data cycle or continues on to a repeated START condition. To generate a single transmit cycle, the I2C Master Slave Address (I2CMSA) register is written with the desired address, the R/S bit is cleared, and the Control register is written with ACK=X (0 or 1), STOP=1, START=1, and RUN=1 to perform the operation and stop. When the operation is completed (or aborted due an error), the interrupt pin becomes active and the data may be read from the I2C Master Data (I2CMDR) register. When the I2C module operates in Master receiver mode, the ACK bit is normally set causing the I2C bus controller to transmit an acknowledge automatically after each byte. This bit must be cleared when the I2C bus controller requires no further data to be transmitted from the slave transmitter. When operating in slave mode, the STARTRIS and STOPRIS bits in the I2C Slave Raw Interrupt Status (I2CSRIS) register indicate detection of start and stop conditions on the bus and the I2C Slave Masked Interrupt Status (I2CSMIS) register can be configured to allow STARTRIS and STOPRIS to be promoted to controller interrupts (when interrupts are enabled). 18.3.1.2 Data Format with 7-Bit Address Data transfers follow the format shown in Figure 18-4. After the START condition, a slave address is transmitted. This address is 7-bits long followed by an eighth bit, which is a data direction bit (R/S bit in the I2CMSA register). If the R/S bit is clear, it indicates a transmit operation (send), and if it is set, it indicates a request for data (receive). A data transfer is always terminated by a STOP condition generated by the master, however, a master can initiate communications with another device on the bus by generating a repeated START condition and addressing another slave without first generating a STOP condition. Various combinations of receive/transmit formats are then possible within a single transfer. Figure 18-4. Complete Data Transfer with a 7-Bit Address SDA MSB SCL 1 Start 2 LSB R/S ACK 7 8 9 MSB 1 2 Slave address 7 Data LSB ACK 8 9 Stop The first seven bits of the first byte make up the slave address (see Figure 18-5). The eighth bit determines the direction of the message. A zero in the R/S position of the first byte means that the June 18, 2014 1279 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface master transmits (sends) data to the selected slave, and a one in this position means that the master receives data from the slave. Figure 18-5. R/S Bit in First Byte MSB LSB R/S Slave address 18.3.1.3 Data Validity The data on the SDA line must be stable during the high period of the clock, and the data line can only change when SCL is Low (see Figure 18-6). Figure 18-6. Data Validity During Bit Transfer on the I2C Bus SDA SCL 18.3.1.4 Data line Change stable of data allowed Acknowledge All bus transactions have a required acknowledge clock cycle that is generated by the master. During the acknowledge cycle, the transmitter (which can be the master or slave) releases the SDA line. To acknowledge the transaction, the receiver must pull down SDA during the acknowledge clock cycle. The data transmitted out by the receiver during the acknowledge cycle must comply with the data validity requirements described in “Data Validity” on page 1280. When a slave receiver does not acknowledge the slave address, SDA must be left High by the slave so that the master can generate a STOP condition and abort the current transfer. If the master device is acting as a receiver during a transfer, it is responsible for acknowledging each transfer made by the slave. Because the master controls the number of bytes in the transfer, it signals the end of data to the slave transmitter by not generating an acknowledge on the last data byte. The slave transmitter must then release SDA to allow the master to generate the STOP or a repeated START condition. If the slave is required to provide a manual ACK or NACK, the I2C Slave ACK Control (I2CSACKCTL) register allows the slave to NACK for invalid data or command or ACK for valid data or command. When this operation is enabled, the MCU slave module I2C clock is pulled low after the last data bit until this register is written with the indicated response. 18.3.1.5 Repeated Start The I2C master module has the capability of executing a repeated START (transmit or receive) after an initial transfer has occurred. A repeated start sequence for a Master transmit is as follows: 1. When the device is in the idle state, the Master writes the slave address to the I2CMSA register and configures the R/S bit for the desired transfer type. 1280 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 2. Data is written to the I2CMDR register. 3. When the BUSY bit in the I2CMCS register is 0 , the Master writes 0x3 to the I2CMCS register to initiate a transfer. 4. The Master does not generate a STOP condition but instead writes another slave address to the I2CMSA register and then writes 0x3 to initiate the repeated START. A repeated start sequence for a Master receive is similar: 1. When the device is in idle, the Master writes the slave address to the I2CMSA register and configures the R/S bit for the desired transfer type. 2. The master reads data from the I2CMDR register. 3. When the BUSY bit in the I2CMCS register is 0 , the Master writes 0x3 to the I2CMCS register to initiate a transfer. 4. The Master does not generate a STOP condition but instead writes another slave address to the I2CMSA register and then writes 0x3 to initiate the repeated START. For more information on repeated START, refer to Figure 18-12 on page 1294 and Figure 18-13 on page 1295. 18.3.1.6 Clock Low Timeout (CLTO) The I2C slave can extend the transaction by pulling the clock low periodically to create a slow bit transfer rate. The I2C module has a 12-bit programmable counter that is used to track how long the clock has been held low. The upper 8 bits of the count value are software programmable through the I2C Master Clock Low Timeout Count (I2CMCLKOCNT) register. The lower four bits are not user visible and are 0x0. The CNTL value programmed in the I2CMCLKOCNT register has to be greater than 0x01. The application can program the eight most significant bits of the counter to reflect the acceptable cumulative low period in transaction. The count is loaded at the START condition and counts down on each falling edge of the internal bus clock of the Master. Note that the internal bus clock generated for this counter keeps running at the programmed I2C speed even if SCL is held low on the bus. Upon reaching terminal count, the master state machine forces ABORT on the bus by issuing a STOP condition at the instance of SCL and SDA release. As an example, if an I2C module was operating at 100 kHz speed, programming the I2CMCLKOCNT register to 0xDA would translate to the value 0xDA0 since the lower four bits are set to 0x0. This would translate to a decimal value of 3488 clocks or a cumulative clock low period of 34.88 ms at 100 kHz. The CLKRIS bit in the I2C Master Raw Interrupt Status (I2CMRIS) register is set when the clock timeout period is reached, allowing the master to start corrective action to resolve the remote slave state. In addition, the CLKTO bit in the I2C Master Control/Status (I2CMCS) register is set; this bit is cleared when a STOP condition is sent or during the I2C master reset. The status of the raw SDA and SCL signals are readable by software through the SDA and SCL bits in the I2C Master Bus Monitor (I2CMBMON) register to help determine the state of the remote slave. In the event of a CLTO condition, application software must choose how it intends to attempt bus recovery. Most applications may attempt to manually toggle the I2C pins to force the slave to let go of the clock signal (a common solution is to attempt to force a STOP on the bus). If a CLTO is detected before the end of a burst transfer, and the bus is successfully recovered by the master, the master hardware attempts to finish the pending burst operation. Depending on the state of the June 18, 2014 1281 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface slave after bus recovery, the actual behavior on the bus varies. If the slave resumes in a state where it can acknowledge the master (essentially, where it was before the bus hang), it continues where it left off. However, if the slave resumes in a reset state (or if a forced STOP by the master causes the slave to enter the idle state), it may ignore the master's attempt to complete the burst operation and NAK the first data byte that the master sends or requests. Since the behavior of slaves cannot always be predicted, it is suggested that the application software always write the STOP bit in the I2C Master Configuration (I2CMCR) register during the CLTO interrupt service routine. This limits the amount of data the master attempts to send or receive upon bus recovery to a single byte, and after the single byte is on the wire, the master issues a STOP. An alternative solution is to have the application software reset the I2C peripheral before attempting to manually recover the bus. This solution allows the I2C master hardware to be returned to a known good (and idle) state before attempting to recover a stuck bus and prevents any unwanted data from appearing on the wire. Note: 18.3.1.7 The Master Clock Low Timeout counter counts for the entire time SCL is held Low continuously. If SCL is deasserted at any point, the Master Clock Low Timeout Counter is reloaded with the value in the I2CMCLKOCNT register and begins counting down from this value. Dual Address The I2C interface supports dual address capability for the slave. The additional programmable address is provided and can be matched if enabled. In legacy mode with dual address disabled, the I2C slave provides an ACK on the bus if the address matches the OAR field in the I2CSOAR register. In dual address mode, the I2C slave provides an ACK on the bus if either the OAR field in the I2CSOAR register or the OAR2 field in the I2CSOAR2 register is matched. The enable for dual address is programmable through the OAR2EN bit in the I2CSOAR2 register and there is no disable on the legacy address. The OAR2SEL bit in the I2CSCSR register indicates if the address that was ACKed is the alternate address or not. When this bit is clear, it indicates either legacy operation or no address match. 18.3.1.8 Arbitration A master may start a transfer only if the bus is idle. It's possible for two or more masters to generate a START condition within minimum hold time of the START condition. In these situations, an arbitration scheme takes place on the SDA line, while SCL is High. During arbitration, the first of the competing master devices to place a 1 (High) on SDA, while another master transmits a 0 (Low), switches off its data output stage and retires until the bus is idle again. Arbitration can take place over several bits. Its first stage is a comparison of address bits, and if both masters are trying to address the same device, arbitration continues on to the comparison of data bits. If arbitration is lost when the I2C master is initiating a BURST with the TX FIFO enabled, the application should execute the following steps to correctly handle the arbitration loss: 1. Flush and disable the TX FIFO 2. Clear and mask the TXFE interrupt by clearing the TXFEIM bit in the I2CMIMR register. Once the bus is IDLE, the TXFIFO can be filled and enabled, the TXFE bit can be unmasked and a new BURST transaction can be initiated. 1282 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 18.3.1.9 Glitch Suppression in Multi-Master Configuration When a multi-master configuration is being used, the PULSEL bit in the I2CMTPR register can be programmed to provide glitch suppression on the SCL and SDA lines and assure proper signal values. The glitch suppression value is in terms of buffered system clocks. Note that all signals will be delayed internally when glitch suppression is nonzero. For example, if PULSEL is set to 0x7, 31 clocks should be added onto the calculation for the expected transaction time. 18.3.1.10 SMBus Operation The SMBus interface is based on the I2C protocol; however, some differences exist between the two. These differences must be handled through software in order to make sure the SMBus protocol, including timing specifications, is met. Note that the SMBus 2.0 specification limits the maximum frequency of the interface to 100 KHz, as a result, I2C Standard speed operation is used for SMBus. The SMBus/ I2C slave can extend the transaction if it is not ready by pulling the clock low. The SMbus specification allows the maximum timeout for such elongated transaction to be between 25 to 35 ms. The I2C specification does not have this requirement. The I2C module supports a programmable count to support clock-low timeout for the master to error out and take appropriate action as required. This feature is explained in “Clock Low Timeout (CLTO)” on page 1281. Note that if transactions are extended, a timeout period should be programmed in the I2CMCLKOCNT register, and the CLKRIS bit in the I2CMRIS register should not be masked. Unlike the I2C slave, the SMBus slave must respond with an ACK response to its address regardless of whether it is ready or not. As a result, the I2C slave sends an ACK response to its address and a NACK response on the data byte if it is not ready. The ARBLST bit in the I2CMCS register is set if there were any issues with the transfer. In addition, the slave can send a NACK at any time to force the master to stop sending additional bytes. The I2C Interface supports µDMA for efficient data handling. The µDMA operation needs FIFOs to be enabled for appropriate transfer type to perform I2C Master for burst transfers and all types of Slave transfers. The I2C interface is supported by two channels, one for Rx (I2C to Memory) and one for Tx (Memory to I2C) transfers.. See“FIFO and µDMA Operation” on page 1287 for more information. Quick Command Quick Command is a simple, compact SMBus protocol that sends an address and 1-bit of data in the R/S bit of the I2C header byte to communicate a command to the slave, typically a "turn off" or "turn on". The I2C master peripheral has the ability to send a Quick Command by writing the target address and R/S value into the I2CMSA register followed by a write to I2CMCS with a value of 0x27. SMBus requires the slave to be able to accept and process commands and the master to generate the Quick Command transactions. The master also has the capability to stop the transaction after acknowledgement from a slave. The I2C slave peripheral requires special handling when a Quick Command is sent. In the case where a master sends a Quick Command with the R/S (data) bit cleared, the QCMDST bit in I2CSCSR is set, and the QCMDRW bit shows the data value (which in this case is 0) when the STOPRIS bit is set in I2CSRIS and the STOP interrupt is asserted. In this scenario, a DATARIS interrupt bit is not set. When the master sends a Quick Command with the R/S (data) bit set, the DATARIS bit is set to notify the slave to write a data byte to I2CSDR in which bit 7 is set. A “dummy write” of 0xFF to the I2CSDR register is recommended. After the write to I2CSDR, the STOP interrupt is asserted and the QCMDST and QCMDRW bits are set in the I2CSCSR register to indicate that a quick command read occurred and the last transaction was a Quick Command. Therefore, when the slave must June 18, 2014 1283 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface receive a Quick Command, it should be expecting such a command because it must write the I2CSDR with a specific value when R/S is set. 18.3.2 Available Speed Modes The I2C bus can run in Standard mode (100 kbps), Fast mode (400 kbps), Fast mode plus (1 Mbps) or High-Speed mode (3.4 Mbps, provided correct system clock frequency is set and there is appropriate pull strength on SCL and SDA lines). The selected mode should match the speed of the other I2C devices on the bus. 18.3.2.1 Standard, Fast, and Fast Plus Modes Standard, Fast, and Fast Plus modes are selected using a value in the I2C Master Timer Period (I2CMTPR) register that results in an SCL frequency of 100 kbps for Standard mode, 400 kbps for Fast mode, or 1 Mbps for Fast mode plus. The I2C clock rate is determined by the parameters CLK_PRD, TIMER_PRD, SCL_LP, and SCL_HP where: CLK_PRD is the system clock period SCL_LP is the low phase of SCL (fixed at 6) SCL_HP is the high phase of SCL (fixed at 4) TIMER_PRD is the programmed value in the I2CMTPR register (see page 1313). This value is determined by replacing the known variables in the equation below and solving for TIMER_PRD. The I2C clock period is calculated as follows: SCL_PERIOD = 2 × (1 + TIMER_PRD) × (SCL_LP + SCL_HP) × CLK_PRD For example: CLK_PRD = 50 ns TIMER_PRD = 2 SCL_LP=6 SCL_HP=4 yields a SCL frequency of: 1/SCL_PERIOD = 333 Khz Table 18-2 gives examples of the timer periods that should be used to generate Standard, Fast mode, and Fast mode plus SCL frequencies based on various system clock frequencies. Table 18-2. Examples of I2C Master Timer Period Versus Speed Mode System Clock Timer Period Standard Mode Timer Period Fast Mode Timer Period Fast Mode Plus 4 MHz 0x01 100 Kbps - - - - 6 MHz 0x02 100 Kbps - - - - 12.5 MHz 0x06 89 Kbps 0x01 312 Kbps - - 16.7 MHz 0x08 93 Kbps 0x02 278 Kbps - - 20 MHz 0x09 100 Kbps 0x02 333 Kbps - - 25 MHz 0x0C 96.2 Kbps 0x03 312 Kbps - - 33 MHz 0x10 97.1 Kbps 0x04 330 Kbps - - 1284 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 18-2. Examples of I2C Master Timer Period Versus Speed Mode (continued) 18.3.2.2 System Clock Timer Period Standard Mode Timer Period Fast Mode Timer Period Fast Mode Plus 40 MHz 0x13 100 Kbps 0x04 400 Kbps 0x01 1000 Kbps 50 MHz 0x18 100 Kbps 0x06 357 Kbps 0x02 833 Kbps 80 MHz 0x27 100 Kbps 0x09 400 Kbps 0x03 1000 Kbps 100 MHz 0x31 100 Kbps 0x0C 385 Kbps 0x04 1000 Kbps 120 MHz 0x3B 100 Kbps 0xE 400 Kbps 0x5 1000 Kbps High-Speed Mode The TM4C1294NCPDT I2C peripheral has support for High-speed operation as both a master and slave. High-Speed mode is configured by setting the HS bit in the I2C Master Control/Status (I2CMCS) register. High-Speed mode transmits data at a high bit rate with a 66.6%/33.3% duty cycle, but communication and arbitration are done at Standard, Fast mode, or Fast-mode plus speed, depending on which is selected by the user. When the HS bit in the I2CMCS register is set, current mode pull-ups are enabled. The clock period can be selected using the equation below, but in this case, SCL_LP=2 and SCL_HP=1. SCL_PERIOD = 2 × (1 + TIMER_PRD) × (SCL_LP + SCL_HP) × CLK_PRD So for example: CLK_PRD = 25 ns TIMER_PRD = 1 SCL_LP=2 SCL_HP=1 yields a SCL frequency of: 1/T = 3.33 Mhz Table 18-3 on page 1285 gives examples of timer period and system clock in High-Speed mode. Note that the HS bit in the I2CMTPR register needs to be set for the TPR value to be used in High-Speed mode. Table 18-3. Examples of I2C Master Timer Period in High-Speed Mode System Clock Timer Period Transmission Mode 40 MHz 0x01 3.33 Mbps 50 MHz 0x02 2.77 Mbps 80 MHz 0x03 3.33 Mbps When operating as a master, the protocol is shown in Figure 18-7. The master is responsible for sending a master code byte in either Standard (100 Kbps) or Fast-mode (400 Kbps) before it begins transferring in High-speed mode. The master code byte must contain data in the form of 0000.1XXX and is used to tell the slave devices to prepare for a High-speed transfer. The master code byte should never be acknowledged by a slave since it is only used to indicate that the upcoming data is going to be transferred at a higher data rate. To send the master code byte for a standard high-speed transfer, software should place the value of the master code byte into the I2CMSA register and write the I2CMCS register with a value of 0x13. If a high-speed burst transfer is required, June 18, 2014 1285 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface then to send the master code byte, software should place the value of the master code byte into the I2CMSA register and write the I2CMCS register with 0x50. Either configuration places the I2C master peripheral in High-speed mode, and all subsequent transfers (until STOP) are carried out at High-speed data rate using the normal I2CMCS command bits, without setting the HS bit in the I2CMCS register. Again, setting the HS bit in the I2CMCS register is only necessary during the master code byte. When operating as a High-speed slave, there is no additional software required. Figure 18-7. High-Speed Data Format R/W SDA Device-Specific NAK Address Data SCL Standard (100 KHz) or Fast Mode (400 KHz) High Speed (3.3 Mbps) Note: 18.3.3 High-Speed mode is 3.4 Mbps, provided correct system clock frequency is set and there is appropriate pull strength on SCL and SDA lines. Interrupts The I2C can generate interrupts when the following conditions are observed in the Master Module: ■ Master transaction completed (RIS bit) ■ Master arbitration lost (ARBLOSTRIS bit) ■ Master Address/Data NACK (NACKRIS bit) ■ Master bus timeout (CLKRIS bit) ■ Next byte request (RIS bit) ■ Stop condition on bus detected (STOPRIS bit) ■ Start condition on bus detected (STARTRIS bit) ■ RX DMA interrupt pending (DMARXRIS bit) ■ TX DMA interrupt pending (DMATXRIS bit) ■ Trigger value for FIFO has been reached and a TX FIFO request interrupt is pending (TXRIS bit) ■ Trigger value for FIFO has been reached and a RX FIFO request interrupt is pending (RXRIS bit) ■ Transmit FIFO is empty (TXFERIS bit) ■ Receive FIFO is full (RXFFRIS bit) Interrupts are generated when the following conditions are observed in the Slave Module: 1286 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Slave transaction received (DATARIS bit) ■ Slave transaction requested (DATARIS bit) ■ Slave next byte transfer request (DATARIS bit) ■ Stop condition on bus detected (STOPRIS bit) ■ Start condition on bus detected (STARTRIS bit) ■ RX DMA interrupt pending (DMARXRIS bit) ■ TX DMA interrupt pending (DMATXRIS bit) ■ Programmable trigger value for FIFO has been reached and a TX FIFO request interrupt is pending (TXRIS bit) ■ Programmable trigger value for FIFO has been reached and a RX FIFO request interrupt is pending (RXRIS bit) ■ Transmit FIFO is empty (TXFERIS bit) ■ Receive FIFO is full (RXFFRIS bit) The I2C master and I2C slave modules have separate interrupt registers. Interrupts can be masked by clearing the appropriate bit in the I2CMIMR or I2CSIMR register. Note that the RIS bit in the Master Raw Interrupt Status (I2CMRIS) register and the DATARIS bit in the Slave Raw Interrupt Status (I2CSRIS) register have multiple interrupt causes including a next byte transfer request interrupt. This interrupt is generated when both master and slave are requesting a receive or transmit transaction. 18.3.4 Loopback Operation The I2C modules can be placed into an internal loopback mode for diagnostic or debug work by setting the LPBK bit in the I2C Master Configuration (I2CMCR) register. In loopback mode, the SDA and SCL signals from the master and are tied to the SDA and SCL signals of the slave module to allow internal testing of the device without having to go through I/O. 18.3.5 FIFO and µDMA Operation Both the master and the slave module have the capability to access two 8-byte FIFOs that can be used in conjunction with the µDMA for fast transfer of data. The transmit (TX) FIFO and receive (RX) FIFO can be independently assigned to either the I2C master or I2C slave. Thus, the following FIFO assignments are allowed: ■ The transmit and receive FIFOs can be assigned to the master ■ The transmit and receive FIFOs can be assigned to the slave ■ The transmit FIFO can be assigned to the master, while the receive FIFO is assigned to the slave and vice versa. In most cases, both FIFOs will be assigned to either the master or the slave. The FIFO assignment is configured by programming the TXASGNMT and RXASGNMT bit in the I2C FIFO Control (I2CFIFOCTL) register. June 18, 2014 1287 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Each FIFO has a programmable threshold point which indicates when the FIFO service interrupt should be generated. Additionally, a FIFO receive full and transmit empty interrupt can be enabled in the Interrupt Mask (I2CxIMR) registers of both the master and slave. Note that if we clear the TXFERIS interrupt (by setting the TXFEIC bit) when the TX FIFO is empty, the TXFERIS interrupt does not reassert even though the TX FIFO remains empty in this situation. When a FIFO is not assigned to a master or a slave module, the FIFO interrupt and status signals to the module are forced to a state that indicates the FIFO is empty. For example, if the TX FIFO is assigned to the master module, the status signals to the slave transmit interface indicates that the FIFO is empty. Note: 18.3.5.1 The FIFOs must be empty when reassigning the FIFOs for proper functionality Master Module Burst Mode A BURST command is provided for the master module which allows a sequence of data transfers using the µDMA (or software, if desired) to handle the data in the FIFO. The BURST command is enabled by setting the BURST bit in the Master Control/Status (I2CMCS) register. The number of bytes transferred by a BURST request is programmed in the I2C Master Burst Length (I2CMBLEN) register and a copy of this value is automatically written to the I2C Master Burst Count (I2CMBCNT) register to be used as a down-counter during the BURST transfer. The bytes written to the I2C FIFO Data (I2CFIFODATA) register are transferred to the RX FIFO or TX FIFO depending on whether a transmit or receive is being executed. If data is NACKed during a BURST and the STOP bit is set in the I2CMCS register, the transfer terminates. If the STOP bit is not set, the software application must issue a repeated STOP or START when a NACK interrupt is asserted. In the case of a NACK, the I2CMBCNT register can be used to determine the amount of data that was transferred prior to the BURST termination. If the Address is NACKed during a transfer, then a STOP is issued. Master Module µDMA Functionality When the Master Control/Status (I2CMCS) register is set to enable BURST and the master I2C µDMA channel is enabled in the DMA Channel Map Select n (DMACHMAPn) registers in the µDMA, the master control module will assert either the internal single µDMA request signal (dma_sreq) or multiple µDMA request signal (dma_req) to the µDMA. Note that there are separate dma_req and dma_sreq signals for transmit and receive. A single µDMA request (dma_sreq) will be asserted by the Master module when the Rx FIFO has at least one data byte present in the FIFO and/or when the Tx FIFO has at least one space available to fill. The dma_req (or Burst) signal will be asserted when Rx FIFO fill level is higher than trigger level and/or the Tx FIFO burst length remaining is less than 4 bytes and the FIFO fill level is less than trigger level. If a single transfer or BURST operation has completed, the µDMA sends a dma_done signal to the master module represented by the DMATX/DMARX interrupts in the I2CMIMR/I2CMRIS/I2CMMIS/I2CMICR registers. If the µDMA I2C channel is disabled and software is used to handle the BURST command, software can read the FIFO Status (I2CFIFOSTAT) Register and the Master Burst Count (I2CMBC) register to determine whether the FIFO needs servicing during the BURST transaction. A trigger value can be programmed in the I2CFIFOCTL register to allow for interrupts at various fill levels of the FIFOs. The NACK and ARBLOST bits in the interrupt status registers can be enabled to indicate no acknowledgement of data transfer or an arbitration loss on the bus. When the Master module is transmitting FIFO data, software can fill the Tx FIFO in advance of setting the BURST bit in the I2CMCS register. If the FIFO is empty when the µDMA is enabled for BURST mode, the dma_req and dma_sreq both assert (assuming the I2CMBLEN register is programmed to at least 4 bytes and the Tx FIFO fill level is less than the trigger set). If the I2CMBLEN register value is less than 4 and the Tx FIFO is not full but more than trigger level, only dma_sreq will assert. Single requests will be generated as required to keep the FIFO full until the number of 1288 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller bytes specified in the I2CMBLEN register has been transferred to the FIFO (and the I2CMBCOUNT register reaches 0x0). At this point, no further requests are generated until the next BURST command is issued. If the µDMA is disabled, FIFOs will be serviced based on the interrupts active in the Master interrupt status registers, the FIFO trigger values shown in the I2CFIFOSTATUS register and completion of a BURST transfer. When the Master module is receiving FIFO data, the Rx FIFO is initially empty and no requests are asserted. If data is read from the slave and placed into the Rx FIFO, the dma_sreq signal to the µDMA is asserted to indicate there is data to be transferred. If the Rx FIFO contains at least 4 bytes, the dma_req signal is also asserted. The µDMA will continue to transfer data out of the Rx FIFO until it has reached the amount of bytes programmed in the I2CMBLEN register. Note: 18.3.5.2 The TXFEIM interrupt mask bit in the I2CMIMR register should be clear (masking the TXFE interrupt) when the master is performing an RX Burst from the RXFIFO and should be unmasked before starting a TX FIFO transfers. Slave Module The slave module also has the capability to use the µDMA in Rx and Tx FIFO data transfers. If the Tx FIFO is assigned to the slave module and the TXFIFO bit is set in the I2CSCSR register, the slave module will generate a single µDMA request, dma_sreq, if the master module requests the next byte transfer. If the FIFO fill level is less than the trigger level, a µDMA multiple transfer request, dma_req, will be asserted to continue data transfers from the µDMA. If the Rx FIFO is assigned to the slave module and the RXFIFO bit is set in the I2CSCSR register, then the slave module will generate a signal µDMA request, dma_sreq, if there is any data to be transferred. The dma_req signal will be asserted when the Rx FIFO has more data than the trigger level programmed by the RXTRIG bit in the I2CFIFOCTL register. Note: 18.3.6 Best practice recommends that an application should not switch between the I2CSDR register and TX FIFO or vice versa for successive transactions. Command Sequence Flow Charts This section details the steps required to perform the various I2C transfer types in both master and slave mode. Refer to Table 18-5 on page 1308 for further sequence information. 18.3.6.1 I2C Master Command Sequences The figures that follow show the command sequences available for the I2C master. June 18, 2014 1289 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Figure 18-8. Master Single TRANSMIT Idle Write Slave Address to I2CMSA Sequence may be omitted in a Single Master system Write data to I2CMDR Read I2CMCS NO BUSBSY bit=0? YES Write ---0-111 to I2CMCS Read I2CMCS NO BUSY bit=0? YES Error Service NO ERROR bit=0? YES Idle 1290 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 18-9. Master Single RECEIVE Idle Write Slave Address to I2CMSA Sequence may be omitted in a Single Master system Read I2CMCS NO BUSBSY bit=0? YES Write ---00111 to I2CMCS Read I2CMCS NO BUSY bit=0? YES Error Service NO ERROR bit=0? YES Read data from I2CMDR Idle June 18, 2014 1291 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Figure 18-10. Master TRANSMIT of Multiple Data Bytes Idle Write Slave Address to I2CMSA Sequence may be omitted in a Single Master system Read I2CMCS Write data to I2CMDR BUSY bit=0? YES Read I2CMCS ERROR bit=0? NO NO NO BUSBSY bit=0? YES Write data to I2CMDR YES Write ---0-011 to I2CMCS NO ARBLST bit=1? YES Write ---0-001 to I2CMCS NO Index=n? YES Write ---0-101 to I2CMCS Write ---0-100 to I2CMCS Error Service Idle Read I2CMCS NO BUSY bit=0? YES Error Service NO ERROR bit=0? YES Idle 1292 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 18-11. Master RECEIVE of Multiple Data Bytes Idle Write Slave Address to I2CMSA Sequence may be omitted in a Single Master system Read I2CMCS BUSY bit=0? Read I2CMCS NO YES NO BUSBSY bit=0? ERROR bit=0? NO YES Write ---01011 to I2CMCS NO Read data from I2CMDR ARBLST bit=1? YES Write ---01001 to I2CMCS NO Write ---0-100 to I2CMCS Index=m-1? Error Service YES Write ---00101 to I2CMCS Idle Read I2CMCS BUSY bit=0? NO YES NO ERROR bit=0? YES Error Service Read data from I2CMDR Idle June 18, 2014 1293 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Figure 18-12. Master RECEIVE with Repeated START after Master TRANSMIT Idle Master operates in Master Transmit mode STOP condition is not generated Write Slave Address to I2CMSA Write ---01011 to I2CMCS Master operates in Master Receive mode Repeated START condition is generated with changing data direction Idle 1294 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 18-13. Master TRANSMIT with Repeated START after Master RECEIVE Idle Master operates in Master Receive mode STOP condition is not generated Write Slave Address to I2CMSA Write ---0-011 to I2CMCS Master operates in Master Transmit mode Repeated START condition is generated with changing data direction Idle June 18, 2014 1295 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Figure 18-14. Standard High Speed Mode Master Transmit IDLE write slave address to I2CMSA register Master code and arbitration is always done in FAST or STANDARD mode write „---10011” to I2CMCS register read I2CMCS register no Busy=’0' yes no IDLE Error=’0' yes Normal sequence starts here. The sequence below covers SINGLE send write Slave Address to I2MSA register write Data to I2CMDR register write „---0-111” to I2CMCS register read I2CMCS register no Busy=’0' yes yes IDLE Error=’0' no Error service IDLE 1296 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 18.3.6.2 I2C Slave Command Sequences Figure 18-15 on page 1297 presents the command sequence available for the I2C slave. Figure 18-15. Slave Command Sequence Idle Write OWN Slave Address to I2CSOAR Write -------1 to I2CSCSR Read I2CSCSR NO TREQ bit=1? YES Write data to I2CSDR NO RREQ bit=1? FBR is also valid YES Read data from I2CSDR 18.4 Initialization and Configuration 18.4.1 Configure the I2C Module to Transmit a Single Byte as a Master The following example shows how to configure the I2C module to transmit a single byte as a master. This assumes the system clock is 20 MHz. 1. Enable the I2C clock using the RCGCI2C register in the System Control module (see page 391). 2. Enable the clock to the appropriate GPIO module via the RCGCGPIO register in the System Control module (see page 382). To find out which GPIO port to enable, refer to Table 26-5 on page 1808. 3. In the GPIO module, enable the appropriate pins for their alternate function using the GPIOAFSEL register (see page 770). To determine which GPIOs to configure, see Table 26-4 on page 1797. June 18, 2014 1297 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface 4. Enable the I2CSDA pin for open-drain operation. See page 775. 5. Configure the PMCn fields in the GPIOPCTL register to assign the I2C signals to the appropriate pins. See page 787 and Table 26-5 on page 1808. 6. Initialize the I2C Master by writing the I2CMCR register with a value of 0x0000.0010. 7. Set the desired SCL clock speed of 100 Kbps by writing the I2CMTPR register with the correct value. The value written to the I2CMTPR register represents the number of system clock periods in one SCL clock period. The TPR value is determined by the following equation: TPR = (System Clock/(2*(SCL_LP + SCL_HP)*SCL_CLK))-1; TPR = (20MHz/(2*(6+4)*100000))-1; TPR = 9 Write the I2CMTPR register with the value of 0x0000.0009. 8. Specify the slave address of the master and that the next operation is a Transmit by writing the I2CMSA register with a value of 0x0000.0076. This sets the slave address to 0x3B. 9. Place data (byte) to be transmitted in the data register by writing the I2CMDR register with the desired data. 10. Initiate a single byte transmit of the data from Master to Slave by writing the I2CMCS register with a value of 0x0000.0007 (STOP, START, RUN). 11. Wait until the transmission completes by polling the I2CMCS register's BUSBSY bit until it has been cleared. 12. Check the ERROR bit in the I2CMCS register to confirm the transmit was acknowledged. 18.4.2 Configure the I2C Master to High Speed Mode To configure the I2C master to High Speed mode: 1. Enable the I2C clock using the RCGCI2C register in the System Control module (see page 391). 2. Enable the clock to the appropriate GPIO module via the RCGCGPIO register in the System Control module (see page 382). To find out which GPIO port to enable, refer to Table 26-5 on page 1808. 3. In the GPIO module, enable the appropriate pins for their alternate function using the GPIOAFSEL register (see page 770). To determine which GPIOs to configure, see Table 26-4 on page 1797. 4. Enable the I2CSDA pin for open-drain operation. See page 775. 5. Configure the PMCn fields in the GPIOPCTL register to assign the I2C signals to the appropriate pins. See page 787 and Table 26-5 on page 1808. 6. Initialize the I2C Master by writing the I2CMCR register with a value of 0x0000.0010. 7. Set the desired SCL clock speed of 3.33 Mbps by writing the I2CMTPR register with the correct value. The value written to the I2CMTPR register represents the number of system clock periods in one SCL clock period. The TPR value is determined by the following equation: 1298 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller TPR = (System Clock/(2*(SCL_LP + SCL_HP)*SCL_CLK))-1; TPR = (80 MHz/(2*(2+1)*3330000))-1; TPR = 3 Write the I2CMTPR register with the value of 0x0000.0003. 8. To send the master code byte, software should place the value of the master code byte into the I2CMSA register and write the I2CMCS register with the following value depending on the required operation: ■ For Standard High-Speed mode, the I2CMCS register should be written with 0x13. ■ For Burst High-Speed mode, the I2CMCS register should be written with 0x50. 9. This places the I2C master peripheral in High-speed mode, and all subsequent transfers (until STOP) are carried out at High-speed data rate using the normal I2CMCS command bits, without setting the HS bit in the I2CMCS register. 10. The transaction is ended by setting the STOP bit in the I2CMCS register. 11. Wait until the transmission completes by polling the I2CMCS register's BUSBSY bit until it has been cleared. 12. Check the ERROR bit in the I2CMCS register to confirm the transmit was acknowledged. 18.5 Register Map Table 18-4 on page 1300 lists the I2C registers. All addresses given are relative to the I2C base address: ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ I2C 0: 0x4002.0000 I2C 1: 0x4002.1000 I2C 2: 0x4002.2000 I2C 3: 0x4002.3000 I2C 4: 0x400C.0000 I2C 5: 0x400C.1000 I2C 6: 0x400C.2000 I2C 7: 0x400C.3000 I2C 8: 0x400B.8000 I2C 9: 0x400B.9000 Note that the I2C module clock must be enabled before the registers can be programmed (see page 391). There must be a delay of 3 system clocks after the I2C module clock is enabled before any I2C module registers are accessed. The hw_i2c.h file in the TivaWare™ Driver Library uses a base address of 0x800 for the I2C slave registers. Be aware when using registers with offsets between 0x800 and 0x818 that TivaWare™ for C Series uses an offset between 0x000 and 0x018 with the slave base address. June 18, 2014 1299 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Table 18-4. Inter-Integrated Circuit (I2C) Interface Register Map Offset Name Type Reset Description See page I2C Master 0x000 I2CMSA RW 0x0000.0000 I2C Master Slave Address 1302 0x004 I2CMCS RW 0x0000.0020 I2C Master Control/Status 1303 0x008 I2CMDR RW 0x0000.0000 I2C Master Data 1312 0x00C I2CMTPR RW 0x0000.0001 I2C Master Timer Period 1313 0x010 I2CMIMR RW 0x0000.0000 I2C Master Interrupt Mask 1315 0x014 I2CMRIS RO 0x0000.0000 I2C Master Raw Interrupt Status 1318 0x018 I2CMMIS RO 0x0000.0000 I2C Master Masked Interrupt Status 1321 0x01C I2CMICR WO 0x0000.0000 I2C Master Interrupt Clear 1324 0x020 I2CMCR RW 0x0000.0000 I2C Master Configuration 1326 0x024 I2CMCLKOCNT RW 0x0000.0000 I2C Master Clock Low Timeout Count 1327 0x02C I2CMBMON RO 0x0000.0003 I2C Master Bus Monitor 1328 0x030 I2CMBLEN RW 0x0000.0000 I2C Master Burst Length 1329 0x034 I2CMBCNT RO 0x0000.0000 I2C Master Burst Count 1330 0x800 I2CSOAR RW 0x0000.0000 I2C Slave Own Address 1331 0x804 I2CSCSR RO 0x0000.0000 I2C Slave Control/Status 1332 0x808 I2CSDR RW 0x0000.0000 I2C Slave Data 1335 0x80C I2CSIMR RW 0x0000.0000 I2C Slave Interrupt Mask 1336 0x810 I2CSRIS RO 0x0000.0000 I2C Slave Raw Interrupt Status 1338 0x814 I2CSMIS RO 0x0000.0000 I2C Slave Masked Interrupt Status 1341 0x818 I2CSICR WO 0x0000.0000 I2C Slave Interrupt Clear 1344 0x81C I2CSOAR2 RW 0x0000.0000 I2C Slave Own Address 2 1346 0x820 I2CSACKCTL RW 0x0000.0000 I2C Slave ACK Control 1347 I2C Slave I2C Status and Control 0xF00 I2CFIFODATA RW 0x0000.0000 I2C FIFO Data 1348 0xF04 I2CFIFOCTL RW 0x0004.0004 I2C FIFO Control 1350 0xF08 I2CFIFOSTATUS RO 0x0001.0005 I2C FIFO Status 1352 0xFC0 I2CPP RO 0x0000.0001 I2C Peripheral Properties 1354 0xFC4 I2CPC RO 0x0000.0001 I2C Peripheral Configuration 1355 1300 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 18.6 Register Descriptions (I2C Master) The remainder of this section lists and describes the I2C master registers, in numerical order by address offset. June 18, 2014 1301 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 1: I2C Master Slave Address (I2CMSA), offset 0x000 This register consists of eight bits: seven address bits (A6-A0), and a Receive/Send bit, which determines if the next operation is a Receive (High), or Transmit (Low). I2C Master Slave Address (I2CMSA) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 reserved Type Reset RO 0 RO 0 RO 0 RO 0 SA RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:1 SA RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 0 R/S RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Slave Address This field specifies bits A6 through A0 of the slave address. 0 R/S RW 0 Receive/Send The R/S bit specifies if the next master operation is a Receive (High) or Transmit (Low). Value Description 0 Transmit 1 Receive 1302 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: I2C Master Control/Status (I2CMCS), offset 0x004 This register accesses status bits when read and control bits when written. When read, the status register indicates the state of the I2C bus controller. When written, the control register configures the I2C controller operation. The START bit generates the START or REPEATED START condition. The STOP bit determines if the cycle stops at the end of the data cycle or continues to the next transfer cycle, which could be a repeated START. To generate a single transmit cycle, the I2C Master Slave Address (I2CMSA) register is written with the desired address, the R/S bit is cleared, and this register is written with ACK=X (0 or 1), STOP=1, START=1, and RUN=1 to perform the operation and stop. When the operation is completed (or aborted due an error), an interrupt becomes active and the data may be read from the I2CMDR register. When the I2C module operates in Master receiver mode, the ACK bit is normally set, causing the I2C bus controller to transmit an acknowledge automatically after each byte. This bit must be cleared when the I2C bus controller requires no further data to be transmitted from the slave transmitter. Read-Only Status Register I2C Master Control/Status (I2CMCS) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x004 Type RO, reset 0x0000.0020 31 30 29 28 27 26 25 24 23 Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 reserved ACTDMARX ACTDMATX RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31 ACTDMARX RO 0 RO 0 RO 0 RO 0 7 6 5 4 CLKTO BUSBSY IDLE ARBLST RO 0 RO 0 RO 1 RO 0 DATACK ADRACK RO 0 RO 0 1 0 ERROR BUSY RO 0 RO 0 Description DMA RX Active Status Value Description 30 ACTDMATX RO 0 0 DMA RX is not active 1 DMA RX is active. DMA TX Active Status Value Description 0 DMA TX is not active 1 DMA TX is active. June 18, 2014 1303 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 29:8 reserved RO 0x0000.00 7 CLKTO RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Clock Timeout Error Value Description 0 No clock timeout error. 1 The clock timeout error has occurred. This bit is cleared when the master sends a STOP condition or if the I2C master is reset. 6 BUSBSY RO 0 Bus Busy Value Description 0 The I2C bus is idle. 1 The I2C bus is busy. The bit changes based on the START and STOP conditions. 5 IDLE RO 1 I2C Idle Value Description 4 ARBLST RO 0 0 The I2C controller is not idle. 1 The I2C controller is idle. Arbitration Lost Value Description 3 DATACK RO 0 0 The I2C controller won arbitration. 1 The I2C controller lost arbitration. Acknowledge Data Value Description 2 ADRACK RO 0 0 The transmitted data was acknowledged 1 The transmitted data was not acknowledged. Acknowledge Address Value Description 0 The transmitted address was acknowledged 1 The transmitted address was not acknowledged. 1304 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1 ERROR RO 0 Description Error Value Description 0 No error was detected on the last operation. 1 An error occurred on the last operation. The error can be from the slave address not being acknowledged or the transmit data not being acknowledged. 0 BUSY RO 0 I2C Busy Value Description 0 The controller is idle. 1 The controller is busy. When the BUSY bit is set, the other status bits are not valid. Write-Only Control Register I2C Master Control/Status (I2CMCS) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x004 Type WO, reset 0x0000.0020 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 BURST QCMD HS ACK STOP START RUN WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 Bit/Field Name Type Reset Description 31:7 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 6 BURST WO 0 Burst Enable Value Description 0 Burst operation is disabled. 1 The master is enabled to burst using the receive and transmit FIFOs. See field decoding in Table 18-5 on page 1308. Note that the BURST and RUN bits are mutually exclusive. June 18, 2014 1305 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 5 QCMD WO 0 Description Quick Command Value Description 4 HS WO 0 0 Bus transaction is not a quick command. 1 The bus transaction is a quick command. To execute a quick command, the START, STOP and RUN bits also need to be set. After the quick command is issued, the master generates a STOP. High-Speed Enable Value Description 3 ACK WO 0 0 The master operates in Standard, Fast mode, or Fast mode plus as selected by using a value in the I2CMTPR register that results in an SCL frequency of 100 kbps for Standard mode, 400 kbps for Fast mode, or 1 Mpbs for Fast mode plus. 1 The master operates in High-Speed mode with transmission speeds up to 3.33 Mbps. Data Acknowledge Enable Value Description 2 STOP WO 0 0 The received data byte is not acknowledged automatically by the master. 1 The received data byte is acknowledged automatically by the master. See field decoding in Table 18-5 on page 1308. Generate STOP Value Description 1 START WO 0 0 The controller does not generate the STOP condition. 1 The controller generates the STOP condition. See field decoding in Table 18-5 on page 1308. Generate START Value Description 0 The controller does not generate the START condition. 1 The controller generates the START or repeated START condition. See field decoding in Table 18-5 on page 1308. 1306 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 RUN WO 0 Description I2C Master Enable Value Description 0 In standard and high speed mode, this encoding means the master is unable to transmit or receive data. In Burst mode, this bit is not used and must be set to 0. 1 The master is able to transmit or receive data. Note that this bit cannot be set in Burst mode. See field decoding in Table 18-5 on page 1308. Note that the BURST and RUN bits are mutually exclusive. The Table 18-5 on page 1308 can be read from left to right to determine the next state after programming bits in the I2CMSA and I2CMCS registers. June 18, 2014 1307 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Table 18-5. Write Field Decoding for I2CMCS[6:0] I2CMCS[6:0] Current I2CMSA[0] Next State Description State R/S BURST QCCMD HS ACK STOP START RUN Idle 0 0 0 0 X a 0 1 1 START condition followed by TRANSMIT (master goes to the Master Transmit state). 0 0 0 0 X 1 1 1 START condition followed by a TRANSMIT and STOP condition (master remains in Idle state). 0 1 0 0 X 0 1 0 START condition followed by N FIFO-serviced TRANSMITs (master goes to the Master Transmit state). 0 1 0 0 X 1 1 0 START condition followed by N FIFO-serviced TRANSMITs and STOP condition (master remains in Idle state). 1 0 0 0 0 0 1 1 START condition followed by RECEIVE operation with negative ACK (master goes to the Master Receive state). 0 0 1 0 0 1 1 1 Quick Command (Send). After Quick Command is executed, the master returns to Idle state. 1 0 1 0 0 1 1 1 Quick Command (Receive). After Quick Command is executed, the master returns to Idle state. 1 0 0 0 0 1 1 1 START condition followed by RECEIVE and STOP condition (master remains in Idle state). 1 0 0 0 1 0 1 1 START condition followed by RECEIVE (master goes to the Master Receive state). 1 1 0 0 0 0 1 0 START condition followed by N FIFO-serviced RECEIVE operations with a negative ACK on the last RECEIVE operation (master goes to the Master Receive state). 1 1 0 0 0 1 1 0 START condition followed by N FIFO-serviced RECEIVE operations with a negative ACK on the last RECEIVE and STOP condition (master remains in Idle state). 1 1 0 0 1 0 1 0 START condition followed by N FIFO-serviced RECEIVE operations (master goes to the Master Receive state). 0 0 0 1 0 0 1 1 START/RUN condition where master byte is sent with no ACK; followed by High Speed transmit Operation. All subsequent transfers are carried out using normal transmit commands. 0 1 0 1 0 0 0 0 RUN/BURST condition where master byte is sent with no ACK; followed by High Speed Burst transmit Operation. 1 0 0 0 1 1 1 1 Illegal 1 0 0 0 1 1 1 0 Illegal All other combinations not listed are non-operations. 1308 NOP June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 18-5. Write Field Decoding for I2CMCS[6:0] (continued) I2CMCS[6:0] Current I2CMSA[0] Next State Description State R/S BURST QCCMD HS ACK STOP START RUN X 0 0 0 X 0 0 1 TRANSMIT operation (master remains in Master Transmit state). X 0 0 0 X 1 0 0 STOP condition (master goes to Idle state). X 0 0 0 X 1 0 1 TRANSMIT followed by STOP condition (master goes to Idle state). X 1 0 0 X 0 0 0 N FIFO-serviced TRANSMIT operations (master remains in Master Transmit state). X 1 0 0 X 1 0 0 N FIFO-serviced TRANSMIT operations followed by STOP condition (master goes to Idle state). 0 0 0 0 X 0 1 1 Repeated START condition followed by a TRANSMIT (master remains in Master Transmit state). 0 0 0 0 X 1 1 1 Repeated START condition followed by TRANSMIT and STOP condition (master goes to Idle state). 0 1 0 0 X 0 1 0 Repeated START condition followed by N FIFO-serviced TRANSMIT operations (master remains in Master Transmit state). 0 1 0 0 X 1 1 0 Repeated START condition followed by N FIFO-serviced TRANSMIT operations and STOP condition (master goes to Idle state). 1 0 0 0 0 0 1 1 Repeated START condition followed by a RECEIVE operation with a negative ACK (master goes to Master Receive state). 1 0 0 0 0 1 1 1 Repeated START condition followed by a RECEIVE and STOP condition (master goes to Idle state). 1 0 0 0 1 0 1 1 Repeated START condition followed by RECEIVE (master goes to Master Receive state). 1 1 0 0 0 0 1 0 Repeated START condition followed by N FIFO-serviced RECEIVE operations with a negative ACK on the last RECEIVE operation (master goes to Master Receive state). 1 1 0 0 0 1 1 0 Repeated START condition followed by N FIFO-serviced RECEIVE operations and STOP condition (master goes to Idle state). 1 1 0 0 1 0 1 0 Repeated START condition followed by N FIFO-serviced RECEIVE operations (master goes to Master Receive state). 1 0 0 0 1 1 1 1 Illegal. 1 1 0 0 1 1 1 0 Illegal. Master Transmit All other combinations not listed are non-operations. June 18, 2014 NOP. 1309 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Table 18-5. Write Field Decoding for I2CMCS[6:0] (continued) I2CMCS[6:0] Current I2CMSA[0] Next State Description State R/S BURST QCCMD HS ACK STOP START RUN Master Receive X 0 0 0 0 0 0 1 RECEIVE operation with negative ACK (master remains in Master Receive state). X 0 0 0 X 1 0 0 STOP condition (master goes to Idle state). X 0 0 0 0 1 0 1 RECEIVE followed by STOP condition (master goes to Idle state). X 0 0 0 1 0 0 1 RECEIVE operation (master remains in Master Receive state). X 1 0 0 0 0 0 0 N FIFO-serviced RECEIVE operations with negative ACK on the last RECEIVE (master remains in Master Receive state). X 1 0 0 0 1 0 0 N FIFO-serviced RECEIVE operations followed by STOP condition (master goes to Idle state). X 1 0 0 1 0 0 0 N FIFO-serviced RECEIVE operations (master remains in Master Receive state). X 0 0 0 1 1 0 1 Illegal. b X 1 0 0 1 1 0 0 Illegal. 1 0 0 0 0 0 1 1 Repeated START condition followed by RECEIVE operation with a negative ACK (master remains in Master Receive state). 1 0 0 0 0 1 1 1 Repeated START condition followed by RECEIVE and STOP condition (master goes to Idle state). 1 0 0 0 1 0 1 1 Repeated START condition followed by RECEIVE (master remains in Master Receive state). 1 1 0 0 0 0 1 0 Repeated START condition followed by N FIFO-serviced RECEIVE operations with a negative ACK on the last RECEIVE (master remains in Master Receive state). 1 1 0 0 0 1 1 0 Repeated START condition followed by N FIFO-serviced RECEIVE operations and STOP condition (master goes to Idle state). 1 1 0 0 1 0 1 0 Repeated START condition followed by N FIFO-serviced RECEIVE operations (master remains in Master Receive state). 0 0 0 0 X 0 1 1 Repeated START condition followed by TRANSMIT (master goes to Master Transmit state). 0 0 0 0 X 1 1 1 Repeated START condition followed by TRANSMIT and STOP condition (master goes to Idle state). 0 1 0 0 X 0 1 0 Repeated START condition followed by N FIFO-serviced TRANSMIT operations (master goes to Master Transmit state). 0 1 0 0 X 1 1 0 Repeated START condition followed by N FIFO-serviced TRANSMIT operations and STOP condition (master goes to Idle state). All other combinations not listed are non-operations. NOP. a. An X in a table cell indicates the bit can be 0 or 1. 1310 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller b. In Master Receive mode, a STOP condition should be generated only after a Data Negative Acknowledge executed by the master or an Address Negative Acknowledge executed by the slave. June 18, 2014 1311 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 3: I2C Master Data (I2CMDR), offset 0x008 Important: This register is read-sensitive. See the register description for details. This register contains the data to be transmitted when in the Master Transmit state and the data received when in the Master Receive state. If the BURST bit is enabled in the I2CMCS register, then the I2CFIFODATA register is used for the current data transmit or receive value and this register is ignored. I2C Master Data (I2CMDR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 DATA RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DATA RW 0x00 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. This byte contains the data transferred during a transaction. 1312 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 4: I2C Master Timer Period (I2CMTPR), offset 0x00C This register is programmed to set the timer period for the SCL clock and assign the SCL clock to either standard or high-speed mode. I2C Master Timer Period (I2CMTPR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x00C Type RW, reset 0x0000.0001 31 30 29 28 27 26 25 24 23 22 21 20 19 18 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 HS RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:19 reserved RO 0x0000.00 18:16 PULSEL RW 0x0 17 16 PULSEL RO 0 WO 0 RO 0 RW 0 RW 0 RW 0 3 2 1 0 RW 0 RW 0 RW 1 TPR RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Glitch Suppression Pulse Width This field controls the pulse width select for glitch suppression on the SCL and SDA lines. The following values are the glitch suppression values in terms of system clocks. Value Description 15:8 reserved RO 0x0000.00 0x0 Bypass 0x1 1 clock 0x2 2 clocks 0x3 3 clocks 0x4 4 clocks 0x5 8 clocks 0x6 16 clocks 0x7 31 clocks Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1313 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 7 HS WO 0x0 Description High-Speed Enable Value Description 6:0 TPR RW 0x1 0 The SCL Clock Period set by TPR applies to Standard mode (100 Kbps), Fast-mode (400 Kbps), or Fast-mode plus (1 Mbps). 1 The SCL Clock Period set by TPR applies to High-speed mode (3.33 Mbps). Timer Period This field is used in the equation to configure SCL_PERIOD: SCL_PERIOD = 2×(1 + TPR)×(SCL_LP + SCL_HP)×CLK_PRD where: SCL_PRD is the SCL line period (I2C clock). TPR is the Timer Period register value (range of 1 to 127). SCL_LP is the SCL Low period (fixed at 6). SCL_HP is the SCL High period (fixed at 4). CLK_PRD is the system clock period in ns. 1314 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: I2C Master Interrupt Mask (I2CMIMR), offset 0x010 This register controls whether a raw interrupt is promoted to a controller interrupt. I2C Master Interrupt Mask (I2CMIMR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 RXFFIM TXFEIM RXIM TXIM ARBLOSTIM RW 0 RW 0 RW 0 RW 0 RW 0 STOPIM STARTIM NACKIM DMATXIM DMARXIM RW 0 RW 0 RW 0 RW 0 RW 0 1 0 CLKIM IM RW 0 RW 0 Bit/Field Name Type Reset Description 31:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 RXFFIM RW 0 Receive FIFO Full Interrupt Mask Value Description 10 TXFEIM RW 0 0 The RXFFRIS interrupt is suppressed and not sent to the interrupt controller. 1 The Receive FIFO Full interrupt is sent to the interrupt controller when the RXFFRIS bit in the I2CMRIS register is set. Transmit FIFO Empty Interrupt Mask Note: The TXFEIM interrupt mask bit in the I2CMIMR register should be clear (masking the TXFE interrupt) when the master is performing an RX Burst from the RXFIFO and should be unmasked before starting a TX FIFO transfers. Value Description 0 The TXFERIS interrupt is suppressed and not sent to the interrupt controller. 1 The Transmit FIFO Empty interrupt is sent to the interrupt controller when the TXFERIS bit in the I2CMRIS register is set. June 18, 2014 1315 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 9 RXIM RW 0 Description Receive FIFO Request Interrupt Mask Value Description 8 TXIM RW 0 0 The RXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The RX FIFO Request interrupt is sent to the interrupt controller when the RXRIS bit in the I2CMRIS register is set. Transmit FIFO Request Interrupt Mask Value Description 7 ARBLOSTIM RW 0 0 The TXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The TX FIFO Request interrupt is sent to the interrupt controller when the TXRIS bit in the I2CMRIS register is set. Arbitration Lost Interrupt Mask Value Description 6 STOPIM RW 0 0 The ARBLOSTRIS interrupt is suppressed and not sent to the interrupt controller. 1 The Arbitration Lost interrupt is sent to the interrupt controller when the ARBLOSTRIS bit in the I2CMRIS register is set. STOP Detection Interrupt Mask Value Description 5 STARTIM RW 0 0 The STOPRIS interrupt is suppressed and not sent to the interrupt controller. 1 The STOP detection interrupt is sent to the interrupt controller when the STOPRIS bit in the I2CMRIS register is set. START Detection Interrupt Mask Value Description 4 NACKIM RW 0 0 The STARTRIS interrupt is suppressed and not sent to the interrupt controller. 1 The START detection interrupt is sent to the interrupt controller when the STARTRIS bit in the I2CMRIS register is set. Address/Data NACK Interrupt Mask Value Description 0 The NACKRIS interrupt is suppressed and not sent to the interrupt controller. 1 The address/data NACK interrupt is sent to the interrupt controller when the NACKRIS bit in the I2CMRIS register is set. 1316 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 DMATXIM RW 0 Description Transmit DMA Interrupt Mask Value Description 2 DMARXIM RW 0 0 The DMATXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The transmit DMA complete interrupt is sent to the interrupt controller when the DMATXRIS bit in the I2CMRIS register is set. Receive DMA Interrupt Mask Value Description 1 CLKIM RW 0 0 The DMARXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The receive DMA complete interrupt is sent to the interrupt controller when the DMARXRIS bit in the I2CMRIS register is set. Clock Timeout Interrupt Mask Value Description 0 IM RW 0 0 The CLKRIS interrupt is suppressed and not sent to the interrupt controller. 1 The clock timeout interrupt is sent to the interrupt controller when the CLKRIS bit in the I2CMRIS register is set. Master Interrupt Mask Value Description 0 The RIS interrupt is suppressed and not sent to the interrupt controller. 1 The master interrupt is sent to the interrupt controller when the RIS bit in the I2CMRIS register is set. June 18, 2014 1317 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 6: I2C Master Raw Interrupt Status (I2CMRIS), offset 0x014 This register specifies whether an interrupt is pending. I2C Master Raw Interrupt Status (I2CMRIS) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x014 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 11 10 RXFFRIS TXFERIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 RXRIS TXRIS ARBLOSTRIS RO 0 RO 0 RO 0 STOPRIS STARTRIS NACKRIS DMATXRIS DMARXRIS CLKRIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 0 RIS RO 0 Bit/Field Name Type Reset Description 31:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 RXFFRIS RO 0 Receive FIFO Full Raw Interrupt Status Value Description 0 No interrupt 1 The Receive FIFO Full interrupt is pending. This bit is cleared by writing a 1 to the RXFFIC bit in the I2CMICR register. 10 TXFERIS RO 0 Transmit FIFO Empty Raw Interrupt Status Value Description 0 No interrupt 1 The Transmit FIFO Empty interrupt is pending. This bit is cleared by writing a 1 to the TXFEIC bit in the I2CMICR register. Note that if we clear the TXFERIS interrupt (by setting the TXFEIC bit) when the TX FIFO is empty, the TXFERIS interrupt does not reassert even though the TX FIFO remains empty in this situation. 1318 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 9 RXRIS RO 0 Description Receive FIFO Request Raw Interrupt Status Value Description 0 No interrupt 1 The trigger level for the RX FIFO has been reached or there is data in the FIFO and the burst count is zero. Thus, a RX FIFO request interrupt is pending. This bit is cleared by writing a 1 to the RXIC bit in the I2CMICR register. 8 TXRIS RO 0 Transmit Request Raw Interrupt Status Value Description 0 No interrupt 1 The trigger level for the TX FIFO has been reached and more data is needed to complete the burst. Thus, a TX FIFO request interrupt is pending. This bit is cleared by writing a 1 to the TXIC bit in the I2CMICR register. 7 ARBLOSTRIS RO 0 Arbitration Lost Raw Interrupt Status Value Description 0 No interrupt 1 The Arbitration Lost interrupt is pending. This bit is cleared by writing a 1 to the ARBLOSTIC bit in the I2CMICR register. 6 STOPRIS RO 0 STOP Detection Raw Interrupt Status Value Description 0 No interrupt 1 The STOP Detection interrupt is pending. This bit is cleared by writing a 1 to the STOPIC bit in the I2CMICR register. 5 STARTRIS RO 0 START Detection Raw Interrupt Status Value Description 0 No interrupt 1 The START Detection interrupt is pending. This bit is cleared by writing a 1 to the STARTIC bit in the I2CMICR register. 4 NACKRIS RO 0 Address/Data NACK Raw Interrupt Status Value Description 0 No interrupt 1 The address/data NACK interrupt is pending. This bit is cleared by writing a 1 to the NACKIC bit in the I2CMICR register. June 18, 2014 1319 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 3 DMATXRIS RO 0 Description Transmit DMA Raw Interrupt Status Value Description 0 No interrupt. 1 The transmit DMA complete interrupt is pending. This bit is cleared by writing a 1 to the DMATXIC bit in the I2CMICR register. 2 DMARXRIS RO 0 Receive DMA Raw Interrupt Status Value Description 0 No interrupt. 1 The receive DMA complete interrupt is pending. This bit is cleared by writing a 1 to the DMARXIC bit in the I2CMICR register. 1 CLKRIS RO 0 Clock Timeout Raw Interrupt Status Value Description 0 No interrupt. 1 The clock timeout interrupt is pending. This bit is cleared by writing a 1 to the CLKIC bit in the I2CMICR register. 0 RIS RO 0 Master Raw Interrupt Status This interrupt includes: ■ Master transaction completed ■ Next byte transfer request Value Description 0 No interrupt. 1 A master interrupt is pending. This bit is cleared by writing a 1 to the IC bit in the I2CMICR register. 1320 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 7: I2C Master Masked Interrupt Status (I2CMMIS), offset 0x018 This register specifies whether an interrupt was signaled. I2C Master Masked Interrupt Status (I2CMMIS) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x018 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 11 10 RXFFMIS TXFEMIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 RXMIS TXMIS ARBLOSTMIS RO 0 RO 0 RO 0 STOPMIS STARTMIS NACKMIS DMATXMIS DMARXMIS CLKMIS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 0 MIS RO 0 Bit/Field Name Type Reset Description 31:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 RXFFMIS RO 0 Receive FIFO Full Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Receive FIFO Full interrupt was signaled and is pending. This bit is cleared by writing a 1 to the RXFFIC bit in the I2CMICR register. 10 TXFEMIS RO 0 Transmit FIFO Empty Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Transmit FIFO Empty interrupt was signaled and is pending. This bit is cleared by writing a 1 to the TXFEIC bit in the I2CMICR register. June 18, 2014 1321 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 9 RXMIS RO 0 Description Receive FIFO Request Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Receive FIFO Request interrupt was signaled and is pending. This bit is cleared by writing a 1 to the RXIC bit in the I2CMICR register. 8 TXMIS RO 0 Transmit Request Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Transmit FIFO Request interrupt was signaled and is pending. This bit is cleared by writing a 1 to the TXIC bit in the I2CMICR register. 7 ARBLOSTMIS RO 0 Arbitration Lost Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Arbitration Lost interrupt was signaled and is pending. This bit is cleared by writing a 1 to the ARBLOSTIC bit in the I2CMICR register. 6 STOPMIS RO 0 STOP Detection Interrupt Mask Value Description 0 No interrupt. 1 An unmasked STOP Detection interrupt was signaled and is pending. This bit is cleared by writing a 1 to the STOPIC bit in the I2CMICR register. 5 STARTMIS RO 0 START Detection Interrupt Mask Value Description 0 No interrupt. 1 An unmasked START Detection interrupt was signaled and is pending. This bit is cleared by writing a 1 to the STARTIC bit in the I2CMICR register. 1322 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 NACKMIS RO 0 Description Address/Data NACK Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Address/Data NACK interrupt was signaled and is pending. This bit is cleared by writing a 1 to the NACKIC bit in the I2CMICR register. 3 DMATXMIS RO 0 Transmit DMA Interrupt Status Value Description 0 No interrupt. 1 An unmasked transmit DMA complete interrupt was signaled and is pending. This bit is cleared by writing a 1 to the DMATXIC bit in the I2CMICR register. 2 DMARXMIS RO 0 Receive DMA Interrupt Status Value Description 0 No interrupt. 1 An unmasked receive DMA complete interrupt was signaled and is pending. This bit is cleared by writing a 1 to the DMARXIC bit in the I2CMICR register. 1 CLKMIS RO 0 Clock Timeout Masked Interrupt Status Value Description 0 No interrupt. 1 An unmasked clock timeout interrupt was signaled and is pending. This bit is cleared by writing a 1 to the CLKIC bit in the I2CMICR register. 0 MIS RO 0 Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked master interrupt was signaled and is pending. This bit is cleared by writing a 1 to the IC bit in the I2CMICR register. June 18, 2014 1323 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 8: I2C Master Interrupt Clear (I2CMICR), offset 0x01C This register clears the raw and masked interrupts. I2C Master Interrupt Clear (I2CMICR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x01C Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 15 14 13 12 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 11 10 9 8 7 RXFFIC TXFEIC RXIC TXIC ARBLOSTIC WO 0 WO 0 WO 0 WO 0 WO 0 STOPIC STARTIC NACKIC DMATXIC DMARXIC WO 0 WO 0 WO 0 WO 0 WO 0 1 0 CLKIC IC WO 0 WO 0 Bit/Field Name Type Reset Description 31:12 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 11 RXFFIC WO 0 Receive FIFO Full Interrupt Clear Writing a 1 to this bit clears the RXFFIS bit in the I2CMRIS register and the RXFFMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 10 TXFEIC WO 0 Transmit FIFO Empty Interrupt Clear Writing a 1 to this bit clears the TXFERIS bit in the I2CMRIS register and the TXFEMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 9 RXIC WO 0 Receive FIFO Request Interrupt Clear Writing a 1 to this bit clears the RXRIS bit in the I2CMRIS register and the RXMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 8 TXIC WO 0 Transmit FIFO Request Interrupt Clear Writing a 1 to this bit clears the TXRIS bit in the I2CMRIS register and the TXMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 7 ARBLOSTIC WO 0 Arbitration Lost Interrupt Clear Writing a 1 to this bit clears the ARBLOSTRIS bit in the I2CMRIS register and the ARBLOSTMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 1324 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 6 STOPIC WO 0 Description STOP Detection Interrupt Clear Writing a 1 to this bit clears the STOPRIS bit in the I2CMRIS register and the STOPMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 5 STARTIC WO 0 START Detection Interrupt Clear Writing a 1 to this bit clears the STARTRIS bit in the I2CMRIS register and the STARTMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 4 NACKIC WO 0 Address/Data NACK Interrupt Clear Writing a 1 to this bit clears the NACKRIS bit in the I2CMRIS register and the NACKMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 3 DMATXIC WO 0 Transmit DMA Interrupt Clear Writing a 1 to this bit clears the DMATXRIS bit in the I2CMRIS register and the DMATXMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 2 DMARXIC WO 0 Receive DMA Interrupt Clear Writing a 1 to this bit clears the DMARXRIS bit in the I2CMRIS register and the DMARXMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 1 CLKIC WO 0 Clock Timeout Interrupt Clear Writing a 1 to this bit clears the CLKRIS bit in the I2CMRIS register and the CLKMIS bit in the I2CMMIS register. A read of this register returns no meaningful data. 0 IC WO 0 Master Interrupt Clear Writing a 1 to this bit clears the RIS bit in the I2CMRIS register and the MIS bit in the I2CMMIS register. A read of this register returns no meaningful data. June 18, 2014 1325 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 9: I2C Master Configuration (I2CMCR), offset 0x020 This register configures the mode (Master or Slave), and sets the interface for test mode loopback. I2C Master Configuration (I2CMCR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x020 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:6 reserved RO 0x0000.00 5 SFE RW 0 RO 0 RO 0 5 4 SFE MFE RW 0 RW 0 RO 0 reserved RO 0 RO 0 0 LPBK RO 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Slave Function Enable Value Description 4 MFE RW 0 0 Slave mode is disabled. 1 Slave mode is enabled. I2C Master Function Enable Value Description 3:1 reserved RO 0x0 0 LPBK RW 0 0 Master mode is disabled. 1 Master mode is enabled. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Loopback Value Description 0 Normal operation. 1 The controller in a test mode loopback configuration. 1326 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 10: I2C Master Clock Low Timeout Count (I2CMCLKOCNT), offset 0x024 This register contains the upper 8 bits of a 12-bit counter that can be used to keep the timeout limit for clock stretching by a remote slave. The lower four bits of the counter are not user visible and are always 0x0. Note: The Master Clock Low Timeout counter counts for the entire time SCL is held Low continuously. If SCL is deasserted at any point, the Master Clock Low Timeout Counter is reloaded with the value in the I2CMCLKOCNT register and begins counting down from this value. I2C Master Clock Low Timeout Count (I2CMCLKOCNT) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CNTL RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CNTL RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Master Count This field contains the upper 8 bits of a 12-bit counter for the clock low timeout count. Note: The value of CNTL must be greater than 0x1. June 18, 2014 1327 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 11: I2C Master Bus Monitor (I2CMBMON), offset 0x02C This register is used to determine the SCL and SDA signal status. I2C Master Bus Monitor (I2CMBMON) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x02C Type RO, reset 0x0000.0003 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:2 reserved RO 0x0000.000 1 SDA RO 1 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 1 0 SDA SCL RO 1 RO 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C SDA Status Value Description 0 SCL RO 1 0 The I2CSDA signal is low. 1 The I2CSDA signal is high. I2C SCL Status Value Description 0 The I2CSCL signal is low. 1 The I2CSCL signal is high. 1328 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 12: I2C Master Burst Length (I2CMBLEN), offset 0x030 This register contains the programmed length of bytes that are transferred during a Burst request. I2C Master Burst Length (I2CMBLEN) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x030 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CNTL RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CNTL RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Burst Length This field contains the programmed length of bytes of the Burst Transaction. If BURST is enabled this register must be set to a non-zero value otherwise an error will occur. June 18, 2014 1329 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 13: I2C Master Burst Count (I2CMBCNT), offset 0x034 When BURST is active, the value in the I2CMBLEN register is copied into this register and decremented during the BURST transaction. This register can be used to determine the number of transfers that occurred when a BURST terminates early (as a result of a data NACK). When a BURST completes successfully, this register will contain 0. I2C Master Burst Count (I2CMBCNT) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x034 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 3 2 1 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 CNTL RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 CNTL RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Master Burst Count This field contains the current count-down value of the BURST transaction. 18.7 Register Descriptions (I2C Slave) The remainder of this section lists and describes the I2C slave registers, in numerical order by address offset. 1330 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 14: I2C Slave Own Address (I2CSOAR), offset 0x800 This register consists of seven address bits that identify the TM4C1294NCPDT I2C device on the I2C bus. I2C Slave Own Address (I2CSOAR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x800 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset OAR RO 0 Bit/Field Name Type Reset 31:7 reserved RO 0x0000.00 6:0 OAR RW 0x00 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Slave Own Address This field specifies bits A6 through A0 of the slave address. June 18, 2014 1331 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 15: I2C Slave Control/Status (I2CSCSR), offset 0x804 This register functions as a control register when written, and a status register when read. Read-Only Status Register I2C Slave Control/Status (I2CSCSR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x804 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 FBR TREQ RREQ RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset 21 reserved ACTDMARX ACTDMATX Type Reset 22 RO 0 QCMDRW QCMDST OAR2SEL Bit/Field Name Type Reset 31 ACTDMARX RO 0 RC 0 RC 0 RO 0 Description DMA RX Active Status Value Description 30 ACTDMATX RO 0 0 DMA RX is not active 1 DMA RX is active. DMA TX Active Status Value Description 29:6 reserved RO 0x0000.000 5 QCMDRW RC 0 0 DMA TX is not active 1 DMA TX is active. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Quick Command Read / Write Value Description 0 Quick command was a write 1 Quick command was a read This bit only has meaning when the QCMDST bit is set. 1332 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 QCMDST RC 0 Description Quick Command Status Value Description 3 OAR2SEL RO 0 0 The last transaction was a normal transaction or a transaction has not occurred. 1 The last transaction was a Quick Command transaction. OAR2 Address Matched Value Description 0 Either the address is not matched or the match is in legacy mode. 1 OAR2 address matched and ACKed by the slave. This bit gets reevaluated after every address comparison. 2 FBR RO 0 First Byte Received Value Description 0 The first byte has not been received. 1 The first byte following the slave's own address has been received. This bit is only valid when the RREQ bit is set and is automatically cleared when data has been read from the I2CSDR register. Note: 1 TREQ RO 0 This bit is not used for slave transmit operations. Transmit Request Value Description 0 RREQ RO 0 0 No outstanding transmit request. 1 The I2C controller has been addressed as a slave transmitter and is using clock stretching to delay the master until data has been written to the I2CSDR register. Receive Request Value Description 0 No outstanding receive data. 1 The I2C controller has outstanding receive data from the I2C master and is using clock stretching to delay the master until the data has been read from the I2CSDR register. June 18, 2014 1333 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Write-Only Control Register I2C Slave Control/Status (I2CSCSR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x804 Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RXFIFO TXFIFO DA RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 WO 0 WO 0 WO 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset Description 31:3 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 RXFIFO WO 0 RX FIFO Enable Value Description 1 TXFIFO WO 0 0 Disables RX FIFO 1 Enables RX FIFO TX FIFO Enable Value Description 0 DA WO 0 0 Disables TX FIFO 1 Enables TX FIFO Device Active Value Description 0 Disables the I2C slave operation. 1 Enables the I2C slave operation. Once this bit has been set, it should not be set again unless it has been cleared by writing a 0 or by a reset, otherwise transfer failures may occur. 1334 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 16: I2C Slave Data (I2CSDR), offset 0x808 Important: This register is read-sensitive. See the register description for details. This register contains the data to be transmitted when in the Slave Transmit state, and the data received when in the Slave Receive state. If the RXFIFO bit or TXFIFO bit are enabled in the I2CSCSR register, then this register is ignored and the data value being transferred from the FIFO is contained in the I2CFIFODATA register. Note: Best practice recommends that an application should not switch between the I2CSDR register and TX FIFO or vice versa for successive transactions. I2C Slave Data (I2CSDR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x808 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset DATA RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DATA RW 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Data for Transfer This field contains the data for transfer during a slave receive or transmit operation. June 18, 2014 1335 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 17: I2C Slave Interrupt Mask (I2CSIMR), offset 0x80C This register controls whether a raw interrupt is promoted to a controller interrupt. I2C Slave Interrupt Mask (I2CSIMR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x80C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 15 14 13 RO 0 RO 0 RO 0 RO 0 12 11 10 9 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 RXFFIM TXFEIM RXIM TXIM RW 0 RW 0 RW 0 RW 0 DMATXIM DMARXIM STOPIM STARTIM DATAIM RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 RXFFIM RW 0 Receive FIFO Full Interrupt Mask Value Description 7 TXFEIM RW 0 0 The RXFFRIS interrupt is suppressed and not sent to the interrupt controller. 1 The Receive FIFO Full interrupt is sent to the interrupt controller when the RXFFRIS bit in the I2CSRIS register is set. Transmit FIFO Empty Interrupt Mask Value Description 6 RXIM RW 0 0 The TXFERIS interrupt is suppressed and not sent to the interrupt controller. 1 The Transmit FIFO Empty interrupt is sent to the interrupt controller when the TXFERIS bit in the I2CSRIS register is set. Receive FIFO Request Interrupt Mask Value Description 0 The RXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The RX FIFO Request interrupt is sent to the interrupt controller when the RXRIS bit in the I2CSRIS register is set. 1336 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 5 TXIM RW 0 Description Transmit FIFO Request Interrupt Mask Value Description 4 DMATXIM RW 0 0 The TXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The TX FIFO Request interrupt is sent to the interrupt controller when the TXRIS bit in the I2CSRIS register is set. Transmit DMA Interrupt Mask Value Description 3 DMARXIM RW 0 0 The DMATXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The transmit DMA complete interrupt is sent to the interrupt controller when the DMATXRIS bit in the I2CSRIS register is set. Receive DMA Interrupt Mask Value Description 2 STOPIM RW 0 0 The DMARXRIS interrupt is suppressed and not sent to the interrupt controller. 1 The receive DMA complete interrupt is sent to the interrupt controller when the DMARXRIS bit in the I2CSRIS register is set. Stop Condition Interrupt Mask Value Description 1 STARTIM RW 0 0 The STOPRIS interrupt is suppressed and not sent to the interrupt controller. 1 The STOP condition interrupt is sent to the interrupt controller when the STOPRIS bit in the I2CSRIS register is set. Start Condition Interrupt Mask Value Description 0 DATAIM RW 0 0 The STARTRIS interrupt is suppressed and not sent to the interrupt controller. 1 The START condition interrupt is sent to the interrupt controller when the STARTRIS bit in the I2CSRIS register is set. Data Interrupt Mask Value Description 0 The DATARIS interrupt is suppressed and not sent to the interrupt controller. 1 Data interrupt sent to interrupt controller when DATARIS bit in the I2CSRIS register is set. June 18, 2014 1337 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 18: I2C Slave Raw Interrupt Status (I2CSRIS), offset 0x810 This register specifies whether an interrupt is pending. I2C Slave Raw Interrupt Status (I2CSRIS) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x810 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 15 14 13 RO 0 RO 0 RO 0 RO 0 12 11 10 9 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 RXFFRIS TXFERIS RO 0 RO 0 RO 0 RO 0 RO 0 6 5 RXRIS TXRIS RO 0 RO 0 DMATXRIS DMARXRIS RO 0 RO 0 STOPRIS STARTRIS DATARIS RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 RXFFRIS RO 0 Receive FIFO Full Raw Interrupt Status Value Description 0 No interrupt 1 The Receive FIFO Full interrupt is pending. This bit is cleared by writing a 1 to the RXFFIC bit in the I2CSICR register. 7 TXFERIS RO 0 Transmit FIFO Empty Raw Interrupt Status Value Description 0 No interrupt 1 The Transmit FIFO Empty interrupt is pending. This bit is cleared by writing a 1 to the TXFEIC bit in the I2CSICR register. Note that if the TXFERIS interrupt is cleared (by setting the TXFEIC bit) when the TX FIFO is empty, the TXFERIS interrupt does not reassert even though the TX FIFO remains empty in this situation. 1338 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 6 RXRIS RO 0 Description Receive FIFO Request Raw Interrupt Status Value Description 0 No interrupt 1 The trigger value for the FIFO has been reached and a RX FIFO Request interrupt is pending. This bit is cleared by writing a 1 to the RXIC bit in the I2CSICR register. 5 TXRIS RO 0 Transmit Request Raw Interrupt Status Value Description 0 No interrupt 1 The trigger value for the FIFO has been reached and a TX FIFO Request interrupt is pending. This bit is cleared by writing a 1 to the TXIC bit in the I2CSICR register. 4 DMATXRIS RO 0 Transmit DMA Raw Interrupt Status Value Description 0 No interrupt. 1 A transmit DMA complete interrupt is pending. This bit is cleared by writing a 1 to the DMATXIC bit in the I2CSICR register. 3 DMARXRIS RO 0 Receive DMA Raw Interrupt Status Value Description 0 No interrupt. 1 A receive DMA complete interrupt is pending. This bit is cleared by writing a 1 to the DMARXIC bit in the I2CSICR register. 2 STOPRIS RO 0 Stop Condition Raw Interrupt Status Value Description 0 No interrupt. 1 A STOP condition interrupt is pending. This bit is cleared by writing a 1 to the STOPIC bit in the I2CSICR register. 1 STARTRIS RO 0 Start Condition Raw Interrupt Status Value Description 0 No interrupt. 1 A START condition interrupt is pending. This bit is cleared by writing a 1 to the STARTIC bit in the I2CSICR register. June 18, 2014 1339 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 0 DATARIS RO 0 Description Data Raw Interrupt Status This interrupt encompasses the following: ■ Slave transaction received ■ Slave transaction requested ■ Next byte transfer request Value Description 0 No interrupt. 1 Slave Interrupt is pending. This bit is cleared by writing a 1 to the DATAIC bit in the I2CSICR register. 1340 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 19: I2C Slave Masked Interrupt Status (I2CSMIS), offset 0x814 This register specifies whether an interrupt was signaled. I2C Slave Masked Interrupt Status (I2CSMIS) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x814 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 15 14 13 RO 0 RO 0 RO 0 RO 0 12 11 10 9 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 RXFFMIS TXFEMIS RO 0 RO 0 RO 0 RO 0 RO 0 6 5 RXMIS TXMIS RO 0 RO 0 DMATXMIS DMARXMIS RO 0 RO 0 STOPMIS STARTMIS DATAMIS RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 RXFFMIS RO 0 Receive FIFO Full Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Receive FIFO Full interrupt was signaled and is pending. This bit is cleared by writing a 1 to the RXFFIC bit in the I2CSICR register. 7 TXFEMIS RO 0 Transmit FIFO Empty Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Transmit FIFO Empty interrupt was signaled and is pending. This bit is cleared by writing a 1 to the TXFEIC bit in the I2CSICR register. June 18, 2014 1341 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Bit/Field Name Type Reset 6 RXMIS RO 0 Description Receive FIFO Request Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Receive FIFO Request interrupt was signaled and is pending. This bit is cleared by writing a 1 to the RXIC bit in the I2CSICR register. 5 TXMIS RO 0 Transmit FIFO Request Interrupt Mask Value Description 0 No interrupt. 1 An unmasked Transmit FIFO Request interrupt was signaled and is pending. This bit is cleared by writing a 1 to the TXIC bit in the I2CSICR register. 4 DMATXMIS RO 0 Transmit DMA Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked transmit DMA complete interrupt was signaled is pending. This bit is cleared by writing a 1 to the DMATXIC bit in the I2CSICR register. 3 DMARXMIS RO 0 Receive DMA Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked receive DMA complete interrupt was signaled is pending. This bit is cleared by writing a 1 to the DMARXIC bit in the I2CSICR register. 2 STOPMIS RO 0 Stop Condition Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked STOP condition interrupt was signaled is pending. This bit is cleared by writing a 1 to the STOPIC bit in the I2CSICR register. 1342 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1 STARTMIS RO 0 Description Start Condition Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked START condition interrupt was signaled is pending. This bit is cleared by writing a 1 to the STARTIC bit in the I2CSICR register. 0 DATAMIS RO 0 Data Masked Interrupt Status Value Description 0 An interrupt has not occurred or is masked. 1 An unmasked slave data interrupt was signaled is pending. This bit is cleared by writing a 1 to the DATAIC bit in the I2CSICR register. June 18, 2014 1343 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 20: I2C Slave Interrupt Clear (I2CSICR), offset 0x818 This register clears the raw interrupt. A read of this register returns no meaningful data. I2C Slave Interrupt Clear (I2CSICR) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x818 Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 15 14 13 RO 0 RO 0 RO 0 RO 0 12 11 10 9 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 RXFFIC TXFEIC RXIC TXIC WO 0 WO 0 WO 0 WO 0 DMATXIC DMARXIC STOPIC STARTIC WO 0 WO 0 WO 0 WO 0 0 DATAIC WO 0 Bit/Field Name Type Reset Description 31:9 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 8 RXFFIC WO 0 Receive FIFO Full Interrupt Mask Writing a 1 to this bit clears the RXFFIS bit in the I2CSRIS register and the RXFFMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 7 TXFEIC WO 0 Transmit FIFO Empty Interrupt Mask Writing a 1 to this bit clears the TXFERIS bit in the I2CSRIS register and the TXFEMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 6 RXIC WO 0 Receive Request Interrupt Mask Writing a 1 to this bit clears the RXRIS bit in the I2CSRIS register and the RXMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 5 TXIC WO 0 Transmit Request Interrupt Mask Writing a 1 to this bit clears the TXRIS bit in the I2CSRIS register and the TXMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 4 DMATXIC WO 0 Transmit DMA Interrupt Clear Writing a 1 to this bit clears the DMATXRIS bit in the I2CSRIS register and the DMATXMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 1344 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 DMARXIC WO 0 Description Receive DMA Interrupt Clear Writing a 1 to this bit clears the DMARXRIS bit in the I2CSRIS register and the DMARXMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 2 STOPIC WO 0 Stop Condition Interrupt Clear Writing a 1 to this bit clears the STOPRIS bit in the I2CSRIS register and the STOPMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 1 STARTIC WO 0 Start Condition Interrupt Clear Writing a 1 to this bit clears the STARTRIS bit in the I2CSRIS register and the STARTMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. 0 DATAIC WO 0 Data Interrupt Clear Writing a 1 to this bit clears the DATARIS bit in the I2CSRIS register and the DATMIS bit in the I2CSMIS register. A read of this register returns no meaningful data. June 18, 2014 1345 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 21: I2C Slave Own Address 2 (I2CSOAR2), offset 0x81C This register consists of seven address bits that identify the alternate address for the I2C device on the I2C bus. I2C Slave Own Address 2 (I2CSOAR2) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x81C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset OAR2EN RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 OAR2EN RW 0 RW 0 OAR2 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Slave Own Address 2 Enable Value Description 6:0 OAR2 RW 0x00 0 The alternate address is disabled. 1 Enables the use of the alternate address in the OAR2 field. I2C Slave Own Address 2 This field specifies the alternate OAR2 address. 1346 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 22: I2C Slave ACK Control (I2CSACKCTL), offset 0x820 This register enables the I2C slave to NACK for invalid data or command or ACK for valid data or command. The I2C clock is pulled low after the last data bit until this register is written. I2C Slave ACK Control (I2CSACKCTL) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0x820 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:2 reserved RO 0x0000.000 1 ACKOVAL RW 0 ACKOVAL ACKOEN RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C Slave ACK Override Value Value Description 0 ACKOEN RW 0 0 An ACK is sent indicating valid data or command. 1 A NACK is sent indicating invalid data or command. I2C Slave ACK Override Enable Value Description 18.8 0 A response in not provided. 1 An ACK or NACK is sent according to the value written to the ACKOVAL bit. Register Descriptions (I2C Status and Control) The remainder of this section lists and describes the I2C status and control registers, in numerical order by address offset. June 18, 2014 1347 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 23: I2C FIFO Data (I2CFIFODATA), offset 0xF00 The I2C FIFO Data (I2CFIFODATA) register contains the current value of the top of the RX or TX FIFO stack being used in the a transfer. Read-Only Status Register I2C FIFO Data (I2CFIFODATA) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0xF00 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset DATA RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DATA RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C RX FIFO Read Data Byte This field contains the current byte being read in the RX FIFO stack. 1348 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Write-Only Control Register I2C FIFO Data (I2CFIFODATA) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0xF00 Type WO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 WO 0 reserved Type Reset reserved Type Reset DATA RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7:0 DATA WO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. I2C TX FIFO Write Data Byte This field contains the current byte written to the TX FIFO. For back to back transmit operations, the application should not switch between writing to the I2CSDR register and the I2CFIFODATA. June 18, 2014 1349 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 24: I2C FIFO Control (I2CFIFOCTL), offset 0xF04 The FIFO Control Register can be programmed to control various aspects of the FIFO transaction, such as RX and TX FIFO assignment, byte count value for FIFO triggers and flushing of the FIFOs. I2C FIFO Control (I2CFIFOCTL) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0xF04 Type RW, reset 0x0004.0004 31 30 29 28 27 26 25 24 RXASGNMT RXFLUSH DMARXENA Type Reset RW 0 15 TXASGNMT Type Reset RW 0 23 22 21 20 19 18 reserved RW 0 RW 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 1 14 13 12 11 10 9 8 7 6 5 4 3 2 TXFLUSH DMATXENA RW 0 RW 0 reserved RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31 RXASGNMT RW 0 RO 0 17 16 RXTRIG RW 0 RW 0 1 0 TXTRIG RO 0 RO 0 RO 0 RO 0 RO 0 RW 1 RW 0 RW 0 Description RX Control Assignment Value Description 30 RXFLUSH RW 0 0 RX FIFO is assigned to Master 1 RX FIFO is assigned to Slave RX FIFO Flush Setting this bit will Flush the RX FIFO. This bit will self-clear when the flush has completed. 29 DMARXENA RW 0 DMA RX Channel Enable Value Description 28:19 reserved RO 0x00 0 DMA RX channel disabled 1 DMA RX channel enabled Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1350 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 18:16 RXTRIG RW 0x4 Description RX FIFO Trigger Indicates at what fill level the RX FIFO will generate a trigger. Note: Programming RXTRIG to 0x0 has no effect since no data is present to transfer out of RX FIFO. Value Description 15 TXASGNMT RW 0 0x0 Trigger when RX FIFO contains no bytes 0x1 Trigger when Rx FIFO contains 1 or more bytes 0x2 Trigger when Rx FIFO contains 2 or more bytes 0x3 Trigger when Rx FIFO contains 3 or more bytes 0x4 Trigger when Rx FIFO contains 4 or more bytes 0x5 Trigger when Rx FIFO contains 5 or more bytes 0x6 Trigger when Rx FIFO contains 6 or more bytes 0x7 Trigger when Rx FIFO contains 7 or more bytes. TX Control Assignment Value Description 14 TXFLUSH RW 0 0 TX FIFO is assigned to Master 1 TX FIFO is assigned to Slave TX FIFO Flush Setting this bit will Flush the TX FIFO. This bit will self-clear when the flush has completed. 13 DMATXENA RW 0 DMA TX Channel Enable Value Description 12:3 reserved RO 0x000 2:0 TXTRIG RW 0x4 0 DMA TX channel disabled 1 DMA TX channel enabled Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. TX FIFO Trigger Indicates at what fill level in the TX FIFO a trigger will be generated. Value Description 0x0 Trigger when the TX FIFO is empty. 0x1 Trigger when TX FIFO contains ≤ 1 byte 0x2 Trigger when TX FIFO contains ≤ 2 bytes 0x3 Trigger when TX FIFO ≤ 3 bytes 0x4 Trigger when FIFO ≤ 4 bytes 0x5 Trigger when FIFO ≤ 5 bytes 0x6 Trigger when FIFO ≤ 6 bytes 0x7 Trigger when FIFO ≤ 7 bytes June 18, 2014 1351 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 25: I2C FIFO Status (I2CFIFOSTATUS), offset 0xF08 This register contains the real-time status of the RX and TX FIFOs. I2C FIFO Status (I2CFIFOSTATUS) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0xF08 Type RO, reset 0x0001.0005 31 30 29 28 27 26 25 24 23 22 21 20 19 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 5 4 3 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 18 17 16 RXABVTRIG RXFF RXFE RO 0 RO 0 RO 1 2 1 0 TXBLWTRIG TXFF TXFE RO 1 RO 0 RO 1 Bit/Field Name Type Reset Description 31:19 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 18 RXABVTRIG RO 0 RX FIFO Above Trigger Level Value Description 17 RXFF RO 0 0 The number of bytes in RX FIFO is below the trigger level programmed by the RXTRIG bit in the I2CFIFOCTL register 1 The number of bytes in the RX FIFO is above the trigger level programmed by the RXTRIG bit in the I2CFIFOCTL register RX FIFO Full Value Description 16 RXFE RO 1 0 The RX FIFO is not full. 1 The RX FIFO is full. RX FIFO Empty Value Description 15:3 reserved RO 0x000 0 The RX FIFO is not empty. 1 The RX FIFO is empty. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1352 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2 TXBLWTRIG RO 1 Description TX FIFO Below Trigger Level Value Description 1 TXFF RO 0 0 The number of bytes in TX FIFO is above the trigger level programmed by the TXTRIG bit in the I2CFIFOCTL register 1 The number of bytes in the TX FIFO is below the trigger level programmed by the TXTRIG bit in the I2CFIFOCTL register TX FIFO Full Value Description 0 TXFE RO 1 0 The TX FIFO is not full. 1 The TX FIFO is full. TX FIFO Empty Value Description 0 The TX FIFO is not empty. 1 The TX FIFO is empty. June 18, 2014 1353 Texas Instruments-Production Data Inter-Integrated Circuit (I2C) Interface Register 26: I2C Peripheral Properties (I2CPP), offset 0xFC0 The I2CPP register provides information regarding the properties of the I2C module. I2C Peripheral Properties (I2CPP) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0xFC0 Type RO, reset 0x0000.0001 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 0 HS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 Bit/Field Name Type Reset Description 31:1 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 HS RO 0x1 High-Speed Capable Value Description 0 The interface is capable of Standard, Fast, or Fast mode plus operation. 1 The interface is capable of High-Speed operation. 1354 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 27: I2C Peripheral Configuration (I2CPC), offset 0xFC4 The I2CPC register allows software to enable features present in the I2C module. I2C Peripheral Configuration (I2CPC) I2C 0 base: 0x4002.0000 I2C 1 base: 0x4002.1000 I2C 2 base: 0x4002.2000 I2C 3 base: 0x4002.3000 I2C 4 base: 0x400C.0000 I2C 5 base: 0x400C.1000 I2C 6 base: 0x400C.2000 I2C 7 base: 0x400C.3000 I2C 8 base: 0x400B.8000 I2C 9 base: 0x400B.9000 Offset 0xFC4 Type RO, reset 0x0000.0001 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 0 HS RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 1 Bit/Field Name Type Reset Description 31:1 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 HS RW 1 High-Speed Capable Value Description 0 The interface is set to Standard, Fast or Fast mode plus operation. 1 The interface is set to High-Speed operation. Note that this encoding may only be used if the HS bit in the I2CPP register is set. Otherwise, this encoding is not available. June 18, 2014 1355 Texas Instruments-Production Data Controller Area Network (CAN) Module 19 Controller Area Network (CAN) Module Controller Area Network (CAN) is a multicast, shared serial bus standard for connecting electronic control units (ECUs). CAN was specifically designed to be robust in electromagnetically-noisy environments and can utilize a differential balanced line like RS-485 or a more robust twisted-pair wire. Originally created for automotive purposes, it is also used in many embedded control applications (such as industrial and medical). Bit rates up to 1 Mbps are possible at network lengths less than 40 meters. Decreased bit rates allow longer network distances (for example, 125 Kbps at 500 meters). The TM4C1294NCPDT microcontroller includes two CAN units with the following features: ■ CAN protocol version 2.0 part A/B ■ Bit rates up to 1 Mbps ■ 32 message objects with individual identifier masks ■ Maskable interrupt ■ Disable Automatic Retransmission mode for Time-Triggered CAN (TTCAN) applications ■ Programmable loopback mode for self-test operation ■ Programmable FIFO mode enables storage of multiple message objects ■ Gluelessly attaches to an external CAN transceiver through the CANnTX and CANnRX signals 1356 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 19.1 Block Diagram Figure 19-1. CAN Controller Block Diagram CAN Control CANCTL CANSTS CANERR CANBIT CANINT CANTST CANBRPE CAN Tx CAN Interface 1 CANIF1CRQ CANIF1CMSK CANIF1MSK1 CANIF1MSK2 CANIF1ARB1 CANIF1ARB2 CANIF1MCTL CANIF1DA1 CANIF1DA2 CANIF1DB1 CANIF1DB2 APB Pins APB Interface CAN Core CAN Rx CAN Interface 2 CANIF2CRQ CANIF2CMSK CANIF2MSK1 CANIF2MSK2 CANIF2ARB1 CANIF2ARB2 CANIF2MCTL CANIF2DA1 CANIF2DA2 CANIF2DB1 CANIF2DB2 Message Object Registers CANTXRQ1 CANTXRQ2 CANNWDA1 CANNWDA2 CANMSG1INT CANMSG2INT CANMSG1VAL CANMSG2VAL Message RAM 32 Message Objects 19.2 Signal Description The following table lists the external signals of the CAN controller and describes the function of each. The CAN controller signals are alternate functions for some GPIO signals and default to be GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible GPIO pin placements for the CAN signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the CAN controller function. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the CAN signal to the specified GPIO port pin. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Table 19-1. Controller Area Network Signals (128TQFP) Pin Name CAN0Rx Pin Number Pin Mux / Pin Assignment 33 PA0 (7) Pin Type I Buffer Type Description TTL CAN module 0 receive. June 18, 2014 1357 Texas Instruments-Production Data Controller Area Network (CAN) Module Table 19-1. Controller Area Network Signals (128TQFP) (continued) Pin Name 19.3 Pin Number Pin Mux / Pin Assignment CAN0Tx 34 PA1 (7) CAN1Rx 95 CAN1Tx 96 Pin Type Buffer Type Description O TTL CAN module 0 transmit. PB0 (7) I TTL CAN module 1 receive. PB1 (7) O TTL CAN module 1 transmit. Functional Description The TM4C1294NCPDT CAN controller conforms to the CAN protocol version 2.0 (parts A and B). Message transfers that include data, remote, error, and overload frames with an 11-bit identifier (standard) or a 29-bit identifier (extended) are supported. Transfer rates can be programmed up to 1 Mbps. The CAN module consists of three major parts: ■ CAN protocol controller and message handler ■ Message memory ■ CAN register interface A data frame contains data for transmission, whereas a remote frame contains no data and is used to request the transmission of a specific message object. The CAN data/remote frame is constructed as shown in Figure 19-2. Figure 19-2. CAN Data/Remote Frame Remote Transmission Request Start Of Frame Bus Idle R S Control O Message Delimiter T Field R F Number 1 Of Bits 11 or 29 1 6 Delimiter Bits Data Field CRC Sequence A C K EOP IFS 0 . . . 64 15 1 1 1 7 3 CRC Sequence CRC Field Arbitration Field Bit Stuffing End of Frame Field Bus Idle Interframe Field Acknowledgement Field CAN Data Frame The protocol controller transfers and receives the serial data from the CAN bus and passes the data on to the message handler. The message handler then loads this information into the appropriate message object based on the current filtering and identifiers in the message object memory. The message handler is also responsible for generating interrupts based on events on the CAN bus. 1358 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The message object memory is a set of 32 identical memory blocks that hold the current configuration, status, and actual data for each message object. These memory blocks are accessed via either of the CAN message object register interfaces. The message memory is not directly accessible in the TM4C1294NCPDT memory map, so the TM4C1294NCPDT CAN controller provides an interface to communicate with the message memory via two CAN interface register sets for communicating with the message objects. These two interfaces must be used to read or write to each message object. The two message object interfaces allow parallel access to the CAN controller message objects when multiple objects may have new information that must be processed. In general, one interface is used for transmit data and one for receive data. 19.3.1 Initialization To use the CAN controller, the peripheral clock must be enabled using the RCGC0 register (see page 395). In addition, the clock to the appropriate GPIO module must be enabled via the RCGC2 register (see page 395). To find out which GPIO port to enable, refer to Table 26-4 on page 1797. Set the GPIO AFSEL bits for the appropriate pins (see page 770). Configure the PMCn fields in the GPIOPCTL register to assign the CAN signals to the appropriate pins. See page 787 and Table 26-5 on page 1808. Software initialization is started by setting the INIT bit in the CAN Control (CANCTL) register (with software or by a hardware reset) or by going bus-off, which occurs when the transmitter's error counter exceeds a count of 255. While INIT is set, all message transfers to and from the CAN bus are stopped and the CANnTX signal is held High. Entering the initialization state does not change the configuration of the CAN controller, the message objects, or the error counters. However, some configuration registers are only accessible while in the initialization state. To initialize the CAN controller, set the CAN Bit Timing (CANBIT) register and configure each message object. If a message object is not needed, label it as not valid by clearing the MSGVAL bit in the CAN IFn Arbitration 2 (CANIFnARB2) register. Otherwise, the whole message object must be initialized, as the fields of the message object may not have valid information, causing unexpected results. Both the INIT and CCE bits in the CANCTL register must be set in order to access the CANBIT register and the CAN Baud Rate Prescaler Extension (CANBRPE) register to configure the bit timing. To leave the initialization state, the INIT bit must be cleared. Afterwards, the internal Bit Stream Processor (BSP) synchronizes itself to the data transfer on the CAN bus by waiting for the occurrence of a sequence of 11 consecutive recessive bits (indicating a bus idle condition) before it takes part in bus activities and starts message transfers. Message object initialization does not require the CAN to be in the initialization state and can be done on the fly. However, message objects should all be configured to particular identifiers or set to not valid before message transfer starts. To change the configuration of a message object during normal operation, clear the MSGVAL bit in the CANIFnARB2 register to indicate that the message object is not valid during the change. When the configuration is completed, set the MSGVAL bit again to indicate that the message object is once again valid. 19.3.2 Operation Two sets of CAN Interface Registers (CANIF1x and CANIF2x) are used to access the message objects in the Message RAM. The CAN controller coordinates transfers to and from the Message RAM to and from the registers. The two sets are independent and identical and can be used to queue transactions. Generally, one interface is used to transmit data and one is used to receive data. Once the CAN module is initialized and the INIT bit in the CANCTL register is cleared, the CAN module synchronizes itself to the CAN bus and starts the message transfer. As each message is June 18, 2014 1359 Texas Instruments-Production Data Controller Area Network (CAN) Module received, it goes through the message handler's filtering process, and if it passes through the filter, is stored in the message object specified by the MNUM bit in the CAN IFn Command Request (CANIFnCRQ) register. The whole message (including all arbitration bits, data-length code, and eight data bytes) is stored in the message object. If the Identifier Mask (the MSK bits in the CAN IFn Mask 1 and CAN IFn Mask 2 (CANIFnMSKn) registers) is used, the arbitration bits that are masked to "don't care" may be overwritten in the message object. The CPU may read or write each message at any time via the CAN Interface Registers. The message handler guarantees data consistency in case of concurrent accesses. The transmission of message objects is under the control of the software that is managing the CAN hardware. Message objects can be used for one-time data transfers or can be permanent message objects used to respond in a more periodic manner. Permanent message objects have all arbitration and control set up, and only the data bytes are updated. At the start of transmission, the appropriate TXRQST bit in the CAN Transmission Request n (CANTXRQn) register and the NEWDAT bit in the CAN New Data n (CANNWDAn) register are set. If several transmit messages are assigned to the same message object (when the number of message objects is not sufficient), the whole message object has to be configured before the transmission of this message is requested. The transmission of any number of message objects may be requested at the same time; they are transmitted according to their internal priority, which is based on the message identifier (MNUM) for the message object, with 1 being the highest priority and 32 being the lowest priority. Messages may be updated or set to not valid any time, even when their requested transmission is still pending. The old data is discarded when a message is updated before its pending transmission has started. Depending on the configuration of the message object, the transmission of a message may be requested autonomously by the reception of a remote frame with a matching identifier. Transmission can be automatically started by the reception of a matching remote frame. To enable this mode, set the RMTEN bit in the CAN IFn Message Control (CANIFnMCTL) register. A matching received remote frame causes the TXRQST bit to be set, and the message object automatically transfers its data or generates an interrupt indicating a remote frame was requested. A remote frame can be strictly a single message identifier, or it can be a range of values specified in the message object. The CAN mask registers, CANIFnMSKn, configure which groups of frames are identified as remote frame requests. The UMASK bit in the CANIFnMCTL register enables the MSK bits in the CANIFnMSKn register to filter which frames are identified as a remote frame request. The MXTD bit in the CANIFnMSK2 register should be set if a remote frame request is expected to be triggered by 29-bit extended identifiers. 19.3.3 Transmitting Message Objects If the internal transmit shift register of the CAN module is ready for loading, and if a data transfer is not occurring between the CAN Interface Registers and message RAM, the valid message object with the highest priority that has a pending transmission request is loaded into the transmit shift register by the message handler and the transmission is started. The message object's NEWDAT bit in the CANNWDAn register is cleared. After a successful transmission, and if no new data was written to the message object since the start of the transmission, the TXRQST bit in the CANTXRQn register is cleared. If the CAN controller is configured to interrupt on a successful transmission of a message object, (the TXIE bit in the CAN IFn Message Control (CANIFnMCTL) register is set), the INTPND bit in the CANIFnMCTL register is set after a successful transmission. If the CAN module has lost the arbitration or if an error occurred during the transmission, the message is re-transmitted as soon as the CAN bus is free again. If, meanwhile, the transmission of a message with higher priority has been requested, the messages are transmitted in the order of their priority. 1360 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 19.3.4 Configuring a Transmit Message Object The following steps illustrate how to configure a transmit message object. 1. In the CAN IFn Command Mask (CANIFnCMASK) register: ■ Set the WRNRD bit to specify a write to the CANIFnCMASK register; specify whether to transfer the IDMASK, DIR, and MXTD of the message object into the CAN IFn registers using the MASK bit ■ Specify whether to transfer the ID, DIR, XTD, and MSGVAL of the message object into the interface registers using the ARB bit ■ Specify whether to transfer the control bits into the interface registers using the CONTROL bit ■ Specify whether to clear the INTPND bit in the CANIFnMCTL register using the CLRINTPND bit ■ Specify whether to clear the NEWDAT bit in the CANNWDAn register using the NEWDAT bit ■ Specify which bits to transfer using the DATAA and DATAB bits 2. In the CANIFnMSK1 register, use the MSK[15:0] bits to specify which of the bits in the 29-bit or 11-bit message identifier are used for acceptance filtering. Note that MSK[15:0] in this register are used for bits [15:0] of the 29-bit message identifier and are not used for an 11-bit identifier. A value of 0x00 enables all messages to pass through the acceptance filtering. Also note that in order for these bits to be used for acceptance filtering, they must be enabled by setting the UMASK bit in the CANIFnMCTL register. 3. In the CANIFnMSK2 register, use the MSK[12:0] bits to specify which of the bits in the 29-bit or 11-bit message identifier are used for acceptance filtering. Note that MSK[12:0] are used for bits [28:16] of the 29-bit message identifier; whereas MSK[12:2] are used for bits [10:0] of the 11-bit message identifier. Use the MXTD and MDIR bits to specify whether to use XTD and DIR for acceptance filtering. A value of 0x00 enables all messages to pass through the acceptance filtering. Also note that in order for these bits to be used for acceptance filtering, they must be enabled by setting the UMASK bit in the CANIFnMCTL register. 4. For a 29-bit identifier, configure ID[15:0] in the CANIFnARB1 register for bits [15:0] of the message identifier and ID[12:0] in the CANIFnARB2 register for bits [28:16] of the message identifier. Set the XTD bit to indicate an extended identifier; set the DIR bit to indicate transmit; and set the MSGVAL bit to indicate that the message object is valid. 5. For an 11-bit identifier, disregard the CANIFnARB1 register and configure ID[12:2] in the CANIFnARB2 register for bits [10:0] of the message identifier. Clear the XTD bit to indicate a standard identifier; set the DIR bit to indicate transmit; and set the MSGVAL bit to indicate that the message object is valid. 6. In the CANIFnMCTL register: ■ Optionally set the UMASK bit to enable the mask (MSK, MXTD, and MDIR specified in the CANIFnMSK1 and CANIFnMSK2 registers) for acceptance filtering ■ Optionally set the TXIE bit to enable the INTPND bit to be set after a successful transmission June 18, 2014 1361 Texas Instruments-Production Data Controller Area Network (CAN) Module ■ Optionally set the RMTEN bit to enable the TXRQST bit to be set on the reception of a matching remote frame allowing automatic transmission ■ Set the EOB bit for a single message object ■ Configure the DLC[3:0] field to specify the size of the data frame. Take care during this configuration not to set the NEWDAT, MSGLST, INTPND or TXRQST bits. 7. Load the data to be transmitted into the CAN IFn Data (CANIFnDA1, CANIFnDA2, CANIFnDB1, CANIFnDB2) registers. Byte 0 of the CAN data frame is stored in DATA[7:0] in the CANIFnDA1 register. 8. Program the number of the message object to be transmitted in the MNUM field in the CAN IFn Command Request (CANIFnCRQ) register. 9. When everything is properly configured, set the TXRQST bit in the CANIFnMCTL register. Once this bit is set, the message object is available to be transmitted, depending on priority and bus availability. Note that setting the RMTEN bit in the CANIFnMCTL register can also start message transmission if a matching remote frame has been received. 19.3.5 Updating a Transmit Message Object The CPU may update the data bytes of a Transmit Message Object any time via the CAN Interface Registers and neither the MSGVAL bit in the CANIFnARB2 register nor the TXRQST bits in the CANIFnMCTL register have to be cleared before the update. Even if only some of the data bytes are to be updated, all four bytes of the corresponding CANIFnDAn/CANIFnDBn register have to be valid before the content of that register is transferred to the message object. Either the CPU must write all four bytes into the CANIFnDAn/CANIFnDBn register or the message object is transferred to the CANIFnDAn/CANIFnDBn register before the CPU writes the new data bytes. In order to only update the data in a message object, the WRNRD, DATAA and DATAB bits in the CANIFnMSKn register are set, followed by writing the updated data into CANIFnDA1, CANIFnDA2, CANIFnDB1, and CANIFnDB2 registers, and then the number of the message object is written to the MNUM field in the CAN IFn Command Request (CANIFnCRQ) register. To begin transmission of the new data as soon as possible, set the TXRQST bit in the CANIFnMSKn register. To prevent the clearing of the TXRQST bit in the CANIFnMCTL register at the end of a transmission that may already be in progress while the data is updated, the NEWDAT and TXRQST bits have to be set at the same time in the CANIFnMCTL register. When these bits are set at the same time, NEWDAT is cleared as soon as the new transmission has started. 19.3.6 Accepting Received Message Objects When the arbitration and control field (the ID and XTD bits in the CANIFnARB2 and the RMTEN and DLC[3:0] bits of the CANIFnMCTL register) of an incoming message is completely shifted into the CAN controller, the message handling capability of the controller starts scanning the message RAM for a matching valid message object. To scan the message RAM for a matching message object, the controller uses the acceptance filtering programmed through the mask bits in the CANIFnMSKn register and enabled using the UMASK bit in the CANIFnMCTL register. Each valid message object, starting with object 1, is compared with the incoming message to locate a matching message object in the message RAM. If a match occurs, the scanning is stopped and the message handler proceeds depending on whether it is a data frame or remote frame that was received. 1362 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 19.3.7 Receiving a Data Frame The message handler stores the message from the CAN controller receive shift register into the matching message object in the message RAM. The data bytes, all arbitration bits, and the DLC bits are all stored into the corresponding message object. In this manner, the data bytes are connected with the identifier even if arbitration masks are used. The NEWDAT bit of the CANIFnMCTL register is set to indicate that new data has been received. The CPU should clear this bit when it reads the message object to indicate to the controller that the message has been received, and the buffer is free to receive more messages. If the CAN controller receives a message and the NEWDAT bit is already set, the MSGLST bit in the CANIFnMCTL register is set to indicate that the previous data was lost. If the system requires an interrupt on successful reception of a frame, the RXIE bit of the CANIFnMCTL register should be set. In this case, the INTPND bit of the same register is set, causing the CANINT register to point to the message object that just received a message. The TXRQST bit of this message object should be cleared to prevent the transmission of a remote frame. 19.3.8 Receiving a Remote Frame A remote frame contains no data, but instead specifies which object should be transmitted. When a remote frame is received, three different configurations of the matching message object have to be considered: Table 19-2. Message Object Configurations Configuration in CANIFnMCTL ■ ■ DIR = 1 (direction = transmit); programmed in the At the reception of a matching remote frame, the TXRQST bit of this CANIFnARB2 register message object is set. The rest of the message object remains unchanged, and the controller automatically transfers the data in RMTEN = 1 (set the TXRQST bit of the the message object as soon as possible. CANIFnMCTL register at reception of the frame to enable transmission) ■ UMASK = 1 or 0 ■ DIR = 1 (direction = transmit); programmed in the At the reception of a matching remote frame, the TXRQST bit of this CANIFnARB2 register message object remains unchanged, and the remote frame is ignored. This remote frame is disabled, the data is not transferred RMTEN = 0 (do not change the TXRQST bit of the and nothing indicates that the remote frame ever happened. CANIFnMCTL register at reception of the frame) ■ ■ UMASK = 0 (ignore mask in the CANIFnMSKn register) ■ DIR = 1 (direction = transmit); programmed in the At the reception of a matching remote frame, the TXRQST bit of this CANIFnARB2 register message object is cleared. The arbitration and control field (ID + XTD + RMTEN + DLC) from the shift register is stored into the message RMTEN = 0 (do not change the TXRQST bit of the object in the message RAM, and the NEWDAT bit of this message CANIFnMCTL register at reception of the frame) object is set. The data field of the message object remains unchanged; the remote frame is treated similar to a received data UMASK = 1 (use mask (MSK, MXTD, and MDIR in frame. This mode is useful for a remote data request from another the CANIFnMSKn register) for acceptance filtering) CAN device for which the TM4C1294NCPDT controller does not have readily available data. The software must fill the data and answer the frame manually. ■ ■ 19.3.9 Description Receive/Transmit Priority The receive/transmit priority for the message objects is controlled by the message number. Message object 1 has the highest priority, while message object 32 has the lowest priority. If more than one transmission request is pending, the message objects are transmitted in order based on the message June 18, 2014 1363 Texas Instruments-Production Data Controller Area Network (CAN) Module object with the lowest message number. This prioritization is separate from that of the message identifier which is enforced by the CAN bus. As a result, if message object 1 and message object 2 both have valid messages to be transmitted, message object 1 is always transmitted first regardless of the message identifier in the message object itself. 19.3.10 Configuring a Receive Message Object The following steps illustrate how to configure a receive message object. 1. Program the CAN IFn Command Mask (CANIFnCMASK) register as described in the “Configuring a Transmit Message Object” on page 1361 section, except that the WRNRD bit is set to specify a write to the message RAM. 2. Program the CANIFnMSK1and CANIFnMSK2 registers as described in the “Configuring a Transmit Message Object” on page 1361 section to configure which bits are used for acceptance filtering. Note that in order for these bits to be used for acceptance filtering, they must be enabled by setting the UMASK bit in the CANIFnMCTL register. 3. In the CANIFnMSK2 register, use the MSK[12:0] bits to specify which of the bits in the 29-bit or 11-bit message identifier are used for acceptance filtering. Note that MSK[12:0] are used for bits [28:16] of the 29-bit message identifier; whereas MSK[12:2] are used for bits [10:0] of the 11-bit message identifier. Use the MXTD and MDIR bits to specify whether to use XTD and DIR for acceptance filtering. A value of 0x00 enables all messages to pass through the acceptance filtering. Also note that in order for these bits to be used for acceptance filtering, they must be enabled by setting the UMASK bit in the CANIFnMCTL register. 4. Program the CANIFnARB1 and CANIFnARB2 registers as described in the “Configuring a Transmit Message Object” on page 1361 section to program XTD and ID bits for the message identifier to be received; set the MSGVAL bit to indicate a valid message; and clear the DIR bit to specify receive. 5. In the CANIFnMCTL register: ■ Optionally set the UMASK bit to enable the mask (MSK, MXTD, and MDIR specified in the CANIFnMSK1 and CANIFnMSK2 registers) for acceptance filtering ■ Optionally set the RXIE bit to enable the INTPND bit to be set after a successful reception ■ Clear the RMTEN bit to leave the TXRQST bit unchanged ■ Set the EOB bit for a single message object ■ Configure the DLC[3:0] field to specify the size of the data frame Take care during this configuration not to set the NEWDAT, MSGLST, INTPND or TXRQST bits. 6. Program the number of the message object to be received in the MNUM field in the CAN IFn Command Request (CANIFnCRQ) register. Reception of the message object begins as soon as a matching frame is available on the CAN bus. When the message handler stores a data frame in the message object, it stores the received Data Length Code and eight data bytes in the CANIFnDA1, CANIFnDA2, CANIFnDB1, and CANIFnDB2 register. Byte 0 of the CAN data frame is stored in DATA[7:0] in the CANIFnDA1 register. If the Data Length Code is less than 8, the remaining bytes of the message object are overwritten by unspecified values. 1364 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The CAN mask registers can be used to allow groups of data frames to be received by a message object. The CAN mask registers, CANIFnMSKn, configure which groups of frames are received by a message object. The UMASK bit in the CANIFnMCTL register enables the MSK bits in the CANIFnMSKn register to filter which frames are received. The MXTD bit in the CANIFnMSK2 register should be set if only 29-bit extended identifiers are expected by this message object. 19.3.11 Handling of Received Message Objects The CPU may read a received message any time via the CAN Interface registers because the data consistency is guaranteed by the message handler state machine. Typically, the CPU first writes 0x007F to the CANIFnCMSK register and then writes the number of the message object to the CANIFnCRQ register. That combination transfers the whole received message from the message RAM into the Message Buffer registers (CANIFnMSKn, CANIFnARBn, and CANIFnMCTL). Additionally, the NEWDAT and INTPND bits are cleared in the message RAM, acknowledging that the message has been read and clearing the pending interrupt generated by this message object. If the message object uses masks for acceptance filtering, the CANIFnARBn registers show the full, unmasked ID for the received message. The NEWDAT bit in the CANIFnMCTL register shows whether a new message has been received since the last time this message object was read. The MSGLST bit in the CANIFnMCTL register shows whether more than one message has been received since the last time this message object was read. MSGLST is not automatically cleared, and should be cleared by software after reading its status. Using a remote frame, the CPU may request new data from another CAN node on the CAN bus. Setting the TXRQST bit of a receive object causes the transmission of a remote frame with the receive object's identifier. This remote frame triggers the other CAN node to start the transmission of the matching data frame. If the matching data frame is received before the remote frame could be transmitted, the TXRQST bit is automatically reset. This prevents the possible loss of data when the other device on the CAN bus has already transmitted the data slightly earlier than expected. 19.3.11.1 Configuration of a FIFO Buffer With the exception of the EOB bit in the CANIFnMCTL register, the configuration of receive message objects belonging to a FIFO buffer is the same as the configuration of a single receive message object (see “Configuring a Receive Message Object” on page 1364). To concatenate two or more message objects into a FIFO buffer, the identifiers and masks (if used) of these message objects have to be programmed to matching values. Due to the implicit priority of the message objects, the message object with the lowest message object number is the first message object in a FIFO buffer. The EOB bit of all message objects of a FIFO buffer except the last one must be cleared. The EOB bit of the last message object of a FIFO buffer is set, indicating it is the last entry in the buffer. 19.3.11.2 Reception of Messages with FIFO Buffers Received messages with identifiers matching to a FIFO buffer are stored starting with the message object with the lowest message number. When a message is stored into a message object of a FIFO buffer, the NEWDAT of the CANIFnMCTL register bit of this message object is set. By setting NEWDAT while EOB is clear, the message object is locked and cannot be written to by the message handler until the CPU has cleared the NEWDAT bit. Messages are stored into a FIFO buffer until the last message object of this FIFO buffer is reached. Until all of the preceding message objects have been released by clearing the NEWDAT bit, all further messages for this FIFO buffer are written into the last message object of the FIFO buffer and therefore overwrite previous messages. June 18, 2014 1365 Texas Instruments-Production Data Controller Area Network (CAN) Module 19.3.11.3 Reading from a FIFO Buffer When the CPU transfers the contents of a message object from a FIFO buffer by writing its number to the CANIFnCRQ register, the TXRQST and CLRINTPND bits in the CANIFnCMSK register should be set such that the NEWDAT and INTPEND bits in the CANIFnMCTL register are cleared after the read. The values of these bits in the CANIFnMCTL register always reflect the status of the message object before the bits are cleared. To assure the correct function of a FIFO buffer, the CPU should read out the message objects starting with the message object with the lowest message number. When reading from the FIFO buffer, the user should be aware that a new received message is placed in the message object with the lowest message number for which the NEWDAT bit of the CANIFnMCTL register is clear. As a result, the order of the received messages in the FIFO is not guaranteed. Figure 19-3 on page 1367 shows how a set of message objects which are concatenated to a FIFO Buffer can be handled by the CPU. 1366 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 19-3. Message Objects in a FIFO Buffer START Message Interrupt Read Interrupt Pointer 0x0000 Case Interrupt Pointer else 0x8000 END Status Change Interrupt Handling MNUM = Interrupt Pointer Write MNUM to IFn Command Request (Read Message to IFn Registers, Reset NEWDAT = 0, Reset INTPND = 0 Read IFn Message Control Yes No NEWDAT = 1 Read Data from IFn Data A,B EOB = 1 Yes No MNUM = MNUM + 1 19.3.12 Handling of Interrupts If several interrupts are pending, the CAN Interrupt (CANINT) register points to the pending interrupt with the highest priority, disregarding their chronological order. The status interrupt has the highest June 18, 2014 1367 Texas Instruments-Production Data Controller Area Network (CAN) Module priority. Among the message interrupts, the message object's interrupt with the lowest message number has the highest priority. A message interrupt is cleared by clearing the message object's INTPND bit in the CANIFnMCTL register or by reading the CAN Status (CANSTS) register. The status Interrupt is cleared by reading the CANSTS register. The interrupt identifier INTID in the CANINT register indicates the cause of the interrupt. When no interrupt is pending, the register reads as 0x0000. If the value of the INTID field is different from 0, then an interrupt is pending. If the IE bit is set in the CANCTL register, the interrupt line to the interrupt controller is active. The interrupt line remains active until the INTID field is 0, meaning that all interrupt sources have been cleared (the cause of the interrupt is reset), or until IE is cleared, which disables interrupts from the CAN controller. The INTID field of the CANINT register points to the pending message interrupt with the highest interrupt priority. The SIE bit in the CANCTL register controls whether a change of the RXOK, TXOK, and LEC bits in the CANSTS register can cause an interrupt. The EIE bit in the CANCTLregister controls whether a change of the BOFF and EWARN bits in the CANSTS register can cause an interrupt. The IE bit in the CANCTL register controls whether any interrupt from the CAN controller actually generates an interrupt to the interrupt controller. The CANINT register is updated even when the IE bit in the CANCTL register is clear, but the interrupt is not indicated to the CPU. A value of 0x8000 in the CANINT register indicates that an interrupt is pending because the CAN module has updated, but not necessarily changed, the CANSTS register, indicating that either an error or status interrupt has been generated. A write access to the CANSTS register can clear the RXOK, TXOK, and LEC bits in that same register; however, the only way to clear the source of a status interrupt is to read the CANSTS register. The source of an interrupt can be determined in two ways during interrupt handling. The first is to read the INTID bit in the CANINT register to determine the highest priority interrupt that is pending, and the second is to read the CAN Message Interrupt Pending (CANMSGnINT) register to see all of the message objects that have pending interrupts. An interrupt service routine reading the message that is the source of the interrupt may read the message and clear the message object's INTPND bit at the same time by setting the CLRINTPND bit in the CANIFnCMSK register. Once the INTPND bit has been cleared, the CANINT register contains the message number for the next message object with a pending interrupt. 19.3.13 Test Mode A Test Mode is provided which allows various diagnostics to be performed. Test Mode is entered by setting the TEST bit in the CANCTL register. Once in Test Mode, the TX[1:0], LBACK, SILENT and BASIC bits in the CAN Test (CANTST) register can be used to put the CAN controller into the various diagnostic modes. The RX bit in the CANTST register allows monitoring of the CANnRX signal. All CANTST register functions are disabled when the TEST bit is cleared. 19.3.13.1 Silent Mode Silent Mode can be used to analyze the traffic on a CAN bus without affecting it by the transmission of dominant bits (Acknowledge Bits, Error Frames). The CAN Controller is put in Silent Mode setting the SILENT bit in the CANTST register. In Silent Mode, the CAN controller is able to receive valid data frames and valid remote frames, but it sends only recessive bits on the CAN bus and cannot start a transmission. If the CAN Controller is required to send a dominant bit (ACK bit, overload flag, or active error flag), the bit is rerouted internally so that the CAN Controller monitors this dominant bit, although the CAN bus remains in recessive state. 1368 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 19.3.13.2 Loopback Mode Loopback mode is useful for self-test functions. In Loopback Mode, the CAN Controller internally routes the CANnTX signal on to the CANnRX signal and treats its own transmitted messages as received messages and stores them (if they pass acceptance filtering) into the message buffer. The CAN Controller is put in Loopback Mode by setting the LBACK bit in the CANTST register. To be independent from external stimulation, the CAN Controller ignores acknowledge errors (a recessive bit sampled in the acknowledge slot of a data/remote frame) in Loopback Mode. The actual value of the CANnRX signal is disregarded by the CAN Controller. The transmitted messages can be monitored on the CANnTX signal. 19.3.13.3 Loopback Combined with Silent Mode Loopback Mode and Silent Mode can be combined to allow the CAN Controller to be tested without affecting a running CAN system connected to the CANnTX and CANnRX signals. In this mode, the CANnRX signal is disconnected from the CAN Controller and the CANnTX signal is held recessive. This mode is enabled by setting both the LBACK and SILENT bits in the CANTST register. 19.3.13.4 Basic Mode Basic Mode allows the CAN Controller to be operated without the Message RAM. In Basic Mode, The CANIF1 registers are used as the transmit buffer. The transmission of the contents of the IF1 registers is requested by setting the BUSY bit of the CANIF1CRQ register. The CANIF1 registers are locked while the BUSY bit is set. The BUSY bit indicates that a transmission is pending. As soon the CAN bus is idle, the CANIF1 registers are loaded into the shift register of the CAN Controller and transmission is started. When the transmission has completed, the BUSY bit is cleared and the locked CANIF1 registers are released. A pending transmission can be aborted at any time by clearing the BUSY bit in the CANIF1CRQ register while the CANIF1 registers are locked. If the CPU has cleared the BUSY bit, a possible retransmission in case of lost arbitration or an error is disabled. The CANIF2 Registers are used as a receive buffer. After the reception of a message, the contents of the shift register are stored in the CANIF2 registers, without any acceptance filtering. Additionally, the actual contents of the shift register can be monitored during the message transfer. Each time a read message object is initiated by setting the BUSY bit of the CANIF2CRQ register, the contents of the shift register are stored into the CANIF2 registers. In Basic Mode, all message-object-related control and status bits and of the control bits of the CANIFnCMSK registers are not evaluated. The message number of the CANIFnCRQ registers is also not evaluated. In the CANIF2MCTL register, the NEWDAT and MSGLST bits retain their function, the DLC[3:0] field shows the received DLC, the other control bits are cleared. Basic Mode is enabled by setting the BASIC bit in the CANTST register. 19.3.13.5 Transmit Control Software can directly override control of the CANnTX signal in four different ways. ■ CANnTX is controlled by the CAN Controller ■ The sample point is driven on the CANnTX signal to monitor the bit timing ■ CANnTX drives a low value ■ CANnTX drives a high value June 18, 2014 1369 Texas Instruments-Production Data Controller Area Network (CAN) Module The last two functions, combined with the readable CAN receive pin CANnRX, can be used to check the physical layer of the CAN bus. The Transmit Control function is enabled by programming the TX[1:0] field in the CANTST register. The three test functions for the CANnTX signal interfere with all CAN protocol functions. TX[1:0] must be cleared when CAN message transfer or Loopback Mode, Silent Mode, or Basic Mode are selected. 19.3.14 Bit Timing Configuration Error Considerations Even if minor errors in the configuration of the CAN bit timing do not result in immediate failure, the performance of a CAN network can be reduced significantly. In many cases, the CAN bit synchronization amends a faulty configuration of the CAN bit timing to such a degree that only occasionally an error frame is generated. In the case of arbitration, however, when two or more CAN nodes simultaneously try to transmit a frame, a misplaced sample point may cause one of the transmitters to become error passive. The analysis of such sporadic errors requires a detailed knowledge of the CAN bit synchronization inside a CAN node and of the CAN nodes' interaction on the CAN bus. 19.3.15 Bit Time and Bit Rate The CAN system supports bit rates in the range of lower than 1 Kbps up to 1000 Kbps. Each member of the CAN network has its own clock generator. The timing parameter of the bit time can be configured individually for each CAN node, creating a common bit rate even though the CAN nodes' oscillator periods may be different. Because of small variations in frequency caused by changes in temperature or voltage and by deteriorating components, these oscillators are not absolutely stable. As long as the variations remain inside a specific oscillator's tolerance range, the CAN nodes are able to compensate for the different bit rates by periodically resynchronizing to the bit stream. According to the CAN specification, the bit time is divided into four segments (see Figure 19-4 on page 1371): the Synchronization Segment, the Propagation Time Segment, the Phase Buffer Segment 1, and the Phase Buffer Segment 2. Each segment consists of a specific, programmable number of time quanta (see Table 19-3 on page 1371). The length of the time quantum (tq), which is the basic time unit of the bit time, is defined by the CAN controller's input clock (fsys) and the Baud Rate Prescaler (BRP): tq = BRP / fsys The fsys input clock is the system clock frequency as configured by the RSCLKCFG register (see page 275). The Synchronization Segment Sync is that part of the bit time where edges of the CAN bus level are expected to occur; the distance between an edge that occurs outside of Sync and the Sync is called the phase error of that edge. The Propagation Time Segment Prop is intended to compensate for the physical delay times within the CAN network. The Phase Buffer Segments Phase1 and Phase2 surround the Sample Point. The (Re-)Synchronization Jump Width (SJW) defines how far a resynchronization may move the Sample Point inside the limits defined by the Phase Buffer Segments to compensate for edge phase errors. A given bit rate may be met by different bit-time configurations, but for the proper function of the CAN network, the physical delay times and the oscillator's tolerance range have to be considered. 1370 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 19-4. CAN Bit Time Nominal CAN Bit Time a b TSEG1 Sync Prop TSEG2 Phase1 c 1 Time Quantum q) (tq Phase2 Sample Point a. TSEG1 = Prop + Phase1 b. TSEG2 = Phase2 c. Phase1 = Phase2 or Phase1 + 1 = Phase2 a Table 19-3. CAN Protocol Ranges Parameter Range Remark BRP [1 .. 64] Defines the length of the time quantum tq. The CANBRPE register can be used to extend the range to 1024. Sync 1 tq Fixed length, synchronization of bus input to system clock Prop [1 .. 8] tq Compensates for the physical delay times Phase1 [1 .. 8] tq May be lengthened temporarily by synchronization Phase2 [1 .. 8] tq May be shortened temporarily by synchronization SJW [1 .. 4] tq May not be longer than either Phase Buffer Segment a. This table describes the minimum programmable ranges required by the CAN protocol. The bit timing configuration is programmed in two register bytes in the CANBIT register. In the CANBIT register, the four components TSEG2, TSEG1, SJW, and BRP have to be programmed to a numerical value that is one less than its functional value; so instead of values in the range of [1..n], values in the range of [0..n-1] are programmed. That way, for example, SJW (functional range of [1..4]) is represented by only two bits in the SJW bit field. Table 19-4 shows the relationship between the CANBIT register values and the parameters. Table 19-4. CANBIT Register Values CANBIT Register Field Setting TSEG2 Phase2 - 1 TSEG1 Prop + Phase1 - 1 SJW SJW - 1 BRP BRP Therefore, the length of the bit time is (programmed values): [TSEG1 + TSEG2 + 3] × tq or (functional values): [Sync + Prop + Phase1 + Phase2] × tq The data in the CANBIT register is the configuration input of the CAN protocol controller. The baud rate prescaler (configured by the BRP field) defines the length of the time quantum, the basic time June 18, 2014 1371 Texas Instruments-Production Data Controller Area Network (CAN) Module unit of the bit time; the bit timing logic (configured by TSEG1, TSEG2, and SJW) defines the number of time quanta in the bit time. The processing of the bit time, the calculation of the position of the sample point, and occasional synchronizations are controlled by the CAN controller and are evaluated once per time quantum. The CAN controller translates messages to and from frames. In addition, the controller generates and discards the enclosing fixed format bits, inserts and extracts stuff bits, calculates and checks the CRC code, performs the error management, and decides which type of synchronization is to be used. The bit value is received or transmitted at the sample point. The information processing time (IPT) is the time after the sample point needed to calculate the next bit to be transmitted on the CAN bus. The IPT includes any of the following: retrieving the next data bit, handling a CRC bit, determining if bit stuffing is required, generating an error flag or simply going idle. The IPT is application-specific but may not be longer than 2 tq; the CAN's IPT is 0 tq. Its length is the lower limit of the programmed length of Phase2. In case of synchronization, Phase2 may be shortened to a value less than IPT, which does not affect bus timing. 19.3.16 Calculating the Bit Timing Parameters Usually, the calculation of the bit timing configuration starts with a required bit rate or bit time. The resulting bit time (1/bit rate) must be an integer multiple of the system clock period. The bit time may consist of 4 to 25 time quanta. Several combinations may lead to the required bit time, allowing iterations of the following steps. The first part of the bit time to be defined is Prop. Its length depends on the delay times measured in the system. A maximum bus length as well as a maximum node delay has to be defined for expandable CAN bus systems. The resulting time for Prop is converted into time quanta (rounded up to the nearest integer multiple of tq). Sync is 1 tq long (fixed), which leaves (bit time - Prop - 1) tq for the two Phase Buffer Segments. If the number of remaining tq is even, the Phase Buffer Segments have the same length, that is, Phase2 = Phase1, else Phase2 = Phase1 + 1. The minimum nominal length of Phase2 has to be regarded as well. Phase2 may not be shorter than the CAN controller's Information Processing Time, which is, depending on the actual implementation, in the range of [0..2] tq. The length of the synchronization jump width is set to the least of 4, Phase1 or Phase2. The oscillator tolerance range necessary for the resulting configuration is calculated by the formula given below: (1 − df ) × fnom ≤ fosc ≤ (1 + df ) × fnom where: df ≤ (Phase _ seg1, Phase _ seg2) min 2 × (13 × tbit − Phase _ Seg 2) ■ df = Maximum tolerance of oscillator frequency ■ fosc Actual=oscillator df =max 2 × dffrequency × fnom ■ fnom = Nominal oscillator frequency Maximum frequency tolerance must take into account the following formulas: 1372 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller − )df × fnom ≤ fosc + )df × fnom (1 −(1df × )fnom ≤ fosc ≤ (1≤ +(1df × )fnom (Phase _ seg 1, Phase _ seg 2) min (Phase _ seg 1, Phase _ seg 2) min df df ≤ ≤ 2 × (13 × tbit − Phase _ Seg 2) 2 × (13 × tbit − Phase _ Seg 2) × df × fnom df df maxmax = 2=× 2df × fnom where: ■ Phase1 and Phase2 are from Table 19-3 on page 1371 ■ tbit = Bit Time ■ dfmax = Maximum difference between two oscillators If more than one configuration is possible, that configuration allowing the highest oscillator tolerance range should be chosen. CAN nodes with different system clocks require different configurations to come to the same bit rate. The calculation of the propagation time in the CAN network, based on the nodes with the longest delay times, is done once for the whole network. The CAN system's oscillator tolerance range is limited by the node with the lowest tolerance range. The calculation may show that bus length or bit rate have to be decreased or that the oscillator frequencies' stability has to be increased in order to find a protocol-compliant configuration of the CAN bit timing. 19.3.16.1 Example for Bit Timing at High Baud Rate In this example, the frequency of CAN clock is 25 MHz, and the bit rate is 1 Mbps. bit time = 1 µs = n * tq = 5 * tq = 200 ns tq = (Baud rate Prescaler)/CAN Baud rate Prescaler = tq * CAN Baud rate Prescaler = 200E-9 * tq Clock Clock 25E6 = 5 tSync = 1 * tq = 200 ns \\fixed at 1 time quanta delay delay delay tProp \\400 is next integer multiple of tq of bus driver 50 ns of receiver circuit 30 ns of bus line (40m) 220 ns 400 ns = 2 * tq bit time = tSync + bit time = tSync + tPhase 1 + tPhase2 tPhase 1 + tPhase2 tPhase 1 + tPhase2 tPhase1 = 1 * tq tPhase2 = 1 * tq tTSeg1 + tTSeg2 = 5 * tq tProp + tPhase 1 + tPhase2 = bit time - tSync - tProp = (5 * tq) - (1 * tq) - (2 * tq) = 2 * tq \\tPhase2 = tPhase1 June 18, 2014 1373 Texas Instruments-Production Data Controller Area Network (CAN) Module tTSeg1 = tProp + tPhase1 tTSeg1 = (2 * tq) + (1 * tq) tTSeg1 = 3 * tq tTSeg2 = tPhase2 tTSeg2 = (Information Processing Time + 1) * tq tTSeg2 = 1 * tq \\Assumes IPT=0 tSJW = 1 * tq \\Least of 4, Phase1 and Phase2 In the above example, the bit field values for the CANBIT register are: = TSeg2 -1 TSEG2 = 1-1 =0 = TSeg1 -1 TSEG1 = 3-1 =2 = SJW -1 SJW = 1-1 =0 = Baud rate prescaler - 1 BRP = 5-1 =4 The final value programmed into the CANBIT register = 0x0204. 19.3.16.2 Example for Bit Timing at Low Baud Rate In this example, the frequency of the CAN clock is 50 MHz, and the bit rate is 100 Kbps. bit time = 10 µs = n * tq = 10 * tq tq = 1 µs tq = (Baud rate Prescaler)/CAN Clock Baud rate Prescaler = tq * CAN Clock Baud rate Prescaler = 1E-6 * 50E6 = 50 tSync = 1 * tq = 1 µs \\fixed at 1 time quanta delay delay delay tProp \\1 µs is next integer multiple of tq of bus driver 200 ns of receiver circuit 80 ns of bus line (40m) 220 ns 1 µs = 1 * tq bit time = tSync + bit time = tSync + tPhase 1 + tPhase2 tPhase 1 + tPhase2 tPhase 1 + tPhase2 tPhase1 = 4 * tq tPhase2 = 4 * tq tTSeg1 + tTSeg2 = 10 * tq tProp + tPhase 1 + tPhase2 = bit time - tSync - tProp = (10 * tq) - (1 * tq) - (1 * tq) = 8 * tq \\tPhase1 = tPhase2 1374 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller tTSeg1 tTSeg1 tTSeg1 tTSeg2 tTSeg2 tTSeg2 = = = = = = tProp + tPhase1 (1 * tq) + (4 * tq) 5 * tq tPhase2 (Information Processing Time + 4) × tq 4 * tq \\Assumes IPT=0 tSJW = 4 * tq \\Least of 4, Phase1, and Phase2 = TSeg2 -1 TSEG2 = 4-1 =3 = TSeg1 -1 TSEG1 = 5-1 =4 = SJW -1 SJW = 4-1 =3 = Baud rate prescaler - 1 BRP = 50-1 =49 The final value programmed into the CANBIT register = 0x34F1. 19.4 Register Map Table 19-5 on page 1375 lists the registers. All addresses given are relative to the CAN base address of: ■ CAN0: 0x4004.0000 ■ CAN1: 0x4004.1000 Note that the CAN controller clock must be enabled before the registers can be programmed (see page 395). There must be a delay of 3 system clocks after the CAN module clock is enabled before any CAN module registers are accessed. Table 19-5. CAN Register Map Type Reset Description See page CANCTL RW 0x0000.0001 CAN Control 1378 0x004 CANSTS RW 0x0000.0000 CAN Status 1380 0x008 CANERR RO 0x0000.0000 CAN Error Counter 1383 0x00C CANBIT RW 0x0000.2301 CAN Bit Timing 1384 0x010 CANINT RO 0x0000.0000 CAN Interrupt 1385 0x014 CANTST RW 0x0000.0000 CAN Test 1386 0x018 CANBRPE RW 0x0000.0000 CAN Baud Rate Prescaler Extension 1388 0x020 CANIF1CRQ RW 0x0000.0001 CAN IF1 Command Request 1389 Offset Name 0x000 June 18, 2014 1375 Texas Instruments-Production Data Controller Area Network (CAN) Module Table 19-5. CAN Register Map (continued) Description See page 0x0000.0000 CAN IF1 Command Mask 1390 RW 0x0000.FFFF CAN IF1 Mask 1 1393 CANIF1MSK2 RW 0x0000.FFFF CAN IF1 Mask 2 1394 0x030 CANIF1ARB1 RW 0x0000.0000 CAN IF1 Arbitration 1 1396 0x034 CANIF1ARB2 RW 0x0000.0000 CAN IF1 Arbitration 2 1397 0x038 CANIF1MCTL RW 0x0000.0000 CAN IF1 Message Control 1399 0x03C CANIF1DA1 RW 0x0000.0000 CAN IF1 Data A1 1402 0x040 CANIF1DA2 RW 0x0000.0000 CAN IF1 Data A2 1402 0x044 CANIF1DB1 RW 0x0000.0000 CAN IF1 Data B1 1402 0x048 CANIF1DB2 RW 0x0000.0000 CAN IF1 Data B2 1402 0x080 CANIF2CRQ RW 0x0000.0001 CAN IF2 Command Request 1389 0x084 CANIF2CMSK RW 0x0000.0000 CAN IF2 Command Mask 1390 0x088 CANIF2MSK1 RW 0x0000.FFFF CAN IF2 Mask 1 1393 0x08C CANIF2MSK2 RW 0x0000.FFFF CAN IF2 Mask 2 1394 0x090 CANIF2ARB1 RW 0x0000.0000 CAN IF2 Arbitration 1 1396 0x094 CANIF2ARB2 RW 0x0000.0000 CAN IF2 Arbitration 2 1397 0x098 CANIF2MCTL RW 0x0000.0000 CAN IF2 Message Control 1399 0x09C CANIF2DA1 RW 0x0000.0000 CAN IF2 Data A1 1402 0x0A0 CANIF2DA2 RW 0x0000.0000 CAN IF2 Data A2 1402 0x0A4 CANIF2DB1 RW 0x0000.0000 CAN IF2 Data B1 1402 0x0A8 CANIF2DB2 RW 0x0000.0000 CAN IF2 Data B2 1402 0x100 CANTXRQ1 RO 0x0000.0000 CAN Transmission Request 1 1403 0x104 CANTXRQ2 RO 0x0000.0000 CAN Transmission Request 2 1403 0x120 CANNWDA1 RO 0x0000.0000 CAN New Data 1 1404 0x124 CANNWDA2 RO 0x0000.0000 CAN New Data 2 1404 0x140 CANMSG1INT RO 0x0000.0000 CAN Message 1 Interrupt Pending 1405 0x144 CANMSG2INT RO 0x0000.0000 CAN Message 2 Interrupt Pending 1405 0x160 CANMSG1VAL RO 0x0000.0000 CAN Message 1 Valid 1406 0x164 CANMSG2VAL RO 0x0000.0000 CAN Message 2 Valid 1406 Offset Name Type Reset 0x024 CANIF1CMSK RW 0x028 CANIF1MSK1 0x02C 19.5 CAN Register Descriptions The remainder of this section lists and describes the CAN registers, in numerical order by address offset. There are two sets of Interface Registers that are used to access the Message Objects in 1376 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller the Message RAM: CANIF1x and CANIF2x. The function of the two sets are identical and are used to queue transactions. June 18, 2014 1377 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 1: CAN Control (CANCTL), offset 0x000 This control register initializes the module and enables test mode and interrupts. The bus-off recovery sequence (see CAN Specification Rev. 2.0) cannot be shortened by setting or clearing INIT. If the device goes bus-off, it sets INIT, stopping all bus activities. Once INIT has been cleared by the CPU, the device then waits for 129 occurrences of Bus Idle (129 * 11 consecutive High bits) before resuming normal operations. At the end of the bus-off recovery sequence, the Error Management Counters are reset. During the waiting time after INIT is cleared, each time a sequence of 11 High bits has been monitored, a BITERROR0 code is written to the CANSTS register (the LEC field = 0x5), enabling the CPU to readily check whether the CAN bus is stuck Low or continuously disturbed, and to monitor the proceeding of the bus-off recovery sequence. CAN Control (CANCTL) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x000 Type RW, reset 0x0000.0001 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 TEST CCE DAR reserved EIE SIE IE INIT RW 0 RW 0 RW 0 RO 0 RW 0 RW 0 RW 0 RW 1 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 TEST RW 0 6 5 CCE DAR RW RW 0 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Test Mode Enable Value Description 0 The CAN controller is operating normally. 1 The CAN controller is in test mode. Configuration Change Enable Value Description 0 Write accesses to the CANBIT register are not allowed. 1 Write accesses to the CANBIT register are allowed if the INIT bit is 1. Disable Automatic-Retransmission Value Description 0 Auto-retransmission of disturbed messages is enabled. 1 Auto-retransmission is disabled. 1378 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 EIE RW 0 Error Interrupt Enable 2 1 0 SIE IE INIT RW RW RW 0 0 1 Description Value Description 0 No error status interrupt is generated. 1 A change in the BOFF or EWARN bits in the CANSTS register generates an interrupt. Status Interrupt Enable Value Description 0 No status interrupt is generated. 1 An interrupt is generated when a message has successfully been transmitted or received, or a CAN bus error has been detected. A change in the TXOK, RXOK or LEC bits in the CANSTS register generates an interrupt. CAN Interrupt Enable Value Description 0 Interrupts disabled. 1 Interrupts enabled. Initialization Value Description 0 Normal operation. 1 Initialization started. June 18, 2014 1379 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 2: CAN Status (CANSTS), offset 0x004 Important: This register is read-sensitive. See the register description for details. The status register contains information for interrupt servicing such as Bus-Off, error count threshold, and error types. The LEC field holds the code that indicates the type of the last error to occur on the CAN bus. This field is cleared when a message has been transferred (reception or transmission) without error. The unused error code 0x7 may be written by the CPU to manually set this field to an invalid error so that it can be checked for a change later. An error interrupt is generated by the BOFF and EWARN bits, and a status interrupt is generated by the RXOK, TXOK, and LEC bits, if the corresponding enable bits in the CAN Control (CANCTL) register are set. A change of the EPASS bit or a write to the RXOK, TXOK, or LEC bits does not generate an interrupt. Reading the CAN Status (CANSTS) register clears the CAN Interrupt (CANINT) register, if it is pending. CAN Status (CANSTS) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x004 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 BOFF RO 0 6 EWARN RO 0 RO 0 7 6 5 4 3 BOFF EWARN EPASS RXOK TXOK RO 0 RO 0 RO 0 RW 0 RW 0 RO 0 LEC RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Bus-Off Status Value Description 0 The CAN controller is not in bus-off state. 1 The CAN controller is in bus-off state. Warning Status Value Description 0 Both error counters are below the error warning limit of 96. 1 At least one of the error counters has reached the error warning limit of 96. 1380 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 5 EPASS RO 0 4 RXOK RW 0 Description Error Passive Value Description 0 The CAN module is in the Error Active state, that is, the receive or transmit error count is less than or equal to 127. 1 The CAN module is in the Error Passive state, that is, the receive or transmit error count is greater than 127. Received a Message Successfully Value Description 0 Since this bit was last cleared, no message has been successfully received. 1 Since this bit was last cleared, a message has been successfully received, independent of the result of the acceptance filtering. This bit must be cleared by writing a 0 to it. 3 TXOK RW 0 Transmitted a Message Successfully Value Description 0 Since this bit was last cleared, no message has been successfully transmitted. 1 Since this bit was last cleared, a message has been successfully transmitted error-free and acknowledged by at least one other node. This bit must be cleared by writing a 0 to it. June 18, 2014 1381 Texas Instruments-Production Data Controller Area Network (CAN) Module Bit/Field Name Type Reset 2:0 LEC RW 0x0 Description Last Error Code This is the type of the last error to occur on the CAN bus. Value Description 0x0 No Error 0x1 Stuff Error More than 5 equal bits in a sequence have occurred in a part of a received message where this is not allowed. 0x2 Format Error A fixed format part of the received frame has the wrong format. 0x3 ACK Error The message transmitted was not acknowledged by another node. 0x4 Bit 1 Error When a message is transmitted, the CAN controller monitors the data lines to detect any conflicts. When the arbitration field is transmitted, data conflicts are a part of the arbitration protocol. When other frame fields are transmitted, data conflicts are considered errors. A Bit 1 Error indicates that the device wanted to send a High level (logical 1) but the monitored bus value was Low (logical 0). 0x5 Bit 0 Error A Bit 0 Error indicates that the device wanted to send a Low level (logical 0), but the monitored bus value was High (logical 1). During bus-off recovery, this status is set each time a sequence of 11 High bits has been monitored. By checking for this status, software can monitor the proceeding of the bus-off recovery sequence without any disturbances to the bus. 0x6 CRC Error The CRC checksum was incorrect in the received message, indicating that the calculated value received did not match the calculated CRC of the data. 0x7 No Event When the LEC bit shows this value, no CAN bus event was detected since this value was written to the LEC field. 1382 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: CAN Error Counter (CANERR), offset 0x008 This register contains the error counter values, which can be used to analyze the cause of an error. CAN Error Counter (CANERR) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x008 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RP Type Reset RO 0 REC TEC RO 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 RP RO 0 14:8 REC RO 0x00 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Received Error Passive Value Description 0 The Receive Error counter is below the Error Passive level (127 or less). 1 The Receive Error counter has reached the Error Passive level (128 or greater). Receive Error Counter This field contains the state of the receiver error counter (0 to 127). 7:0 TEC RO 0x00 Transmit Error Counter This field contains the state of the transmit error counter (0 to 255). June 18, 2014 1383 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 4: CAN Bit Timing (CANBIT), offset 0x00C This register is used to program the bit width and bit quantum. Values are programmed to the system clock frequency. This register is write-enabled by setting the CCE and INIT bits in the CANCTL register. See “Bit Time and Bit Rate” on page 1370 for more information. CAN Bit Timing (CANBIT) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x00C Type RW, reset 0x0000.2301 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RW 0 RW 0 RW 0 RW 1 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 1 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 1 reserved Type Reset reserved Type Reset RO 0 TSEG2 RW 0 RW 1 TSEG1 Bit/Field Name Type Reset 31:15 reserved RO 0x0000 14:12 TSEG2 RW 0x2 SJW BRP Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Time Segment after Sample Point 0x00-0x07: The actual interpretation by the hardware of this value is such that one more than the value programmed here is used. So, for example, the reset value of 0x2 means that 3 (2+1) bit time quanta are defined for Phase2 (see Figure 19-4 on page 1371). The bit time quanta is defined by the BRP field. 11:8 TSEG1 RW 0x3 Time Segment Before Sample Point 0x00-0x0F: The actual interpretation by the hardware of this value is such that one more than the value programmed here is used. So, for example, the reset value of 0x3 means that 4 (3+1) bit time quanta are defined for Phase1 (see Figure 19-4 on page 1371). The bit time quanta is defined by the BRP field. 7:6 SJW RW 0x0 (Re)Synchronization Jump Width 0x00-0x03: The actual interpretation by the hardware of this value is such that one more than the value programmed here is used. During the start of frame (SOF), if the CAN controller detects a phase error (misalignment), it can adjust the length of TSEG2 or TSEG1 by the value in SJW. So the reset value of 0 adjusts the length by 1 bit time quanta. 5:0 BRP RW 0x1 Baud Rate Prescaler The value by which the oscillator frequency is divided for generating the bit time quanta. The bit time is built up from a multiple of this quantum. 0x00-0x03F: The actual interpretation by the hardware of this value is such that one more than the value programmed here is used. BRP defines the number of CAN clock periods that make up 1 bit time quanta, so the reset value is 2 bit time quanta (1+1). The CANBRPE register can be used to further divide the bit time. 1384 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: CAN Interrupt (CANINT), offset 0x010 This register indicates the source of the interrupt. If several interrupts are pending, the CAN Interrupt (CANINT) register points to the pending interrupt with the highest priority, disregarding the order in which the interrupts occurred. An interrupt remains pending until the CPU has cleared it. If the INTID field is not 0x0000 (the default) and the IE bit in the CANCTL register is set, the interrupt is active. The interrupt line remains active until the INTID field is cleared by reading the CANSTS register, or until the IE bit in the CANCTL register is cleared. Note: Reading the CAN Status (CANSTS) register clears the CAN Interrupt (CANINT) register, if it is pending. CAN Interrupt (CANINT) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x010 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset INTID Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 INTID RO 0x0000 Interrupt Identifier The number in this field indicates the source of the interrupt. Value Description 0x0000 No interrupt pending 0x0001-0x0020 Number of the message object that caused the interrupt 0x0021-0x7FFF Reserved 0x8000 Status Interrupt 0x8001-0xFFFF Reserved June 18, 2014 1385 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 6: CAN Test (CANTST), offset 0x014 This register is used for self-test and external pin access. It is write-enabled by setting the TEST bit in the CANCTL register. Different test functions may be combined, however, CAN transfers are affected if the TX bits in this register are not zero. CAN Test (CANTST) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x014 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 LBACK SILENT BASIC RO 0 RO 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RX RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 RX RO 0 6:5 TX RW 0x0 TX RW 0 RW 0 reserved RO 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Receive Observation Value Description 0 The CANnRx pin is low. 1 The CANnRx pin is high. Transmit Control Overrides control of the CANnTx pin. Value Description 0x0 CAN Module Control CANnTx is controlled by the CAN module; default operation 0x1 Sample Point The sample point is driven on the CANnTx signal. This mode is useful to monitor bit timing. 0x2 Driven Low CANnTx drives a low value. This mode is useful for checking the physical layer of the CAN bus. 0x3 Driven High CANnTx drives a high value. This mode is useful for checking the physical layer of the CAN bus. 1386 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 LBACK RW 0 3 2 1:0 SILENT BASIC reserved RW RW RO 0 0 0x0 Description Loopback Mode Value Description 0 Loopback mode is disabled. 1 Loopback mode is enabled. In loopback mode, the data from the transmitter is routed into the receiver. Any data on the receive input is ignored. Silent Mode Value Description 0 Silent mode is disabled. 1 Silent mode is enabled. In silent mode, the CAN controller does not transmit data but instead monitors the bus. This mode is also known as Bus Monitor mode. Basic Mode Value Description 0 Basic mode is disabled. 1 Basic mode is enabled. In basic mode, software should use the CANIF1 registers as the transmit buffer and use the CANIF2 registers as the receive buffer. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1387 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 7: CAN Baud Rate Prescaler Extension (CANBRPE), offset 0x018 This register is used to further divide the bit time set with the BRP bit in the CANBIT register. It is write-enabled by setting the CCE bit in the CANCTL register. CAN Baud Rate Prescaler Extension (CANBRPE) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x018 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3:0 BRPE RW 0x0 BRPE Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Baud Rate Prescaler Extension 0x00-0x0F: Extend the BRP bit in the CANBIT register to values up to 1023. The actual interpretation by the hardware is one more than the value programmed by BRPE (MSBs) and BRP (LSBs). 1388 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: CAN IF1 Command Request (CANIF1CRQ), offset 0x020 Register 9: CAN IF2 Command Request (CANIF2CRQ), offset 0x080 A message transfer is started as soon as there is a write of the message object number to the MNUM field when the TXRQST bit in the CANIF1MCTL register is set. With this write operation, the BUSY bit is automatically set to indicate that a transfer between the CAN Interface Registers and the internal message RAM is in progress. After a wait time of 3 to 6 CAN_CLK periods, the transfer between the interface register and the message RAM completes, which then clears the BUSY bit. CAN IFn Command Request (CANIFnCRQ) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x020 Type RW, reset 0x0000.0001 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 1 reserved Type Reset BUSY Type Reset RO 0 reserved RO 0 MNUM Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 BUSY RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Busy Flag Value Description 0 This bit is cleared when read/write action has finished. 1 This bit is set when a write occurs to the message number in this register. 14:6 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5:0 MNUM RW 0x01 Message Number Selects one of the 32 message objects in the message RAM for data transfer. The message objects are numbered from 1 to 32. Value Description 0x00 Reserved 0 is not a valid message number; it is interpreted as 0x20, or object 32. 0x01-0x20 Message Number Indicates specified message object 1 to 32. 0x21-0x3F Reserved Not a valid message number; values are shifted and it is interpreted as 0x01-0x1F. June 18, 2014 1389 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 10: CAN IF1 Command Mask (CANIF1CMSK), offset 0x024 Register 11: CAN IF2 Command Mask (CANIF2CMSK), offset 0x084 Reading the Command Mask registers provides status for various functions. Writing to the Command Mask registers specifies the transfer direction and selects which buffer registers are the source or target of the data transfer. Note that when a read from the message object buffer occurs when the WRNRD bit is clear and the CLRINTPND and/or NEWDAT bits are set, the interrupt pending and/or new data flags in the message object buffer are cleared. CAN IFn Command Mask (CANIFnCMSK) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 WRNRD MASK ARB CONTROL CLRINTPND NEWDAT / TXRQST reserved DATAA DATAB RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 WRNRD RW 0 6 MASK RW 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Write, Not Read Value Description 0 Transfer the data in the CAN message object specified by the MNUM field in the CANIFnCRQ register into the CANIFn registers. 1 Transfer the data in the CANIFn registers to the CAN message object specified by the MNUM field in the CAN Command Request (CANIFnCRQ). Note: Interrupt pending and new data conditions in the message buffer can be cleared by reading from the buffer (WRNRD = 0) when the CLRINTPND and/or NEWDAT bits are set. Access Mask Bits Value Description 0 Mask bits unchanged. 1 Transfer IDMASK + DIR + MXTD of the message object into the Interface registers. 1390 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 5 ARB RW 0 4 3 CONTROL CLRINTPND RW RW 0 0 Description Access Arbitration Bits Value Description 0 Arbitration bits unchanged. 1 Transfer ID + DIR + XTD + MSGVAL of the message object into the Interface registers. Access Control Bits Value Description 0 Control bits unchanged. 1 Transfer control bits from the CANIFnMCTL register into the Interface registers. Clear Interrupt Pending Bit The function of this bit depends on the configuration of the WRNRD bit. Value Description 0 If WRNRD is clear, the interrupt pending status is transferred from the message buffer into the CANIFnMCTL register. If WRNRD is set, the INTPND bit in the message object remains unchanged. 1 If WRNRD is clear, the interrupt pending status is cleared in the message buffer. Note the value of this bit that is transferred to the CANIFnMCTL register always reflects the status of the bits before clearing. If WRNRD is set, the INTPND bit is cleared in the message object. 2 NEWDAT / TXRQST RW 0 NEWDAT / TXRQST Bit The function of this bit depends on the configuration of the WRNRD bit. Value Description 0 If WRNRD is clear, the value of the new data status is transferred from the message buffer into the CANIFnMCTL register. If WRNRD is set, a transmission is not requested. 1 If WRNRD is clear, the new data status is cleared in the message buffer. Note the value of this bit that is transferred to the CANIFnMCTL register always reflects the status of the bits before clearing. If WRNRD is set, a transmission is requested. Note that when this bit is set, the TXRQST bit in the CANIFnMCTL register is ignored. June 18, 2014 1391 Texas Instruments-Production Data Controller Area Network (CAN) Module Bit/Field Name Type Reset 1 DATAA RW 0 Description Access Data Byte 0 to 3 The function of this bit depends on the configuration of the WRNRD bit. Value Description 0 Data bytes 0-3 are unchanged. 1 If WRNRD is clear, transfer data bytes 0-3 in CANIFnDA1 and CANIFnDA2 to the message object. If WRNRD is set, transfer data bytes 0-3 in message object to CANIFnDA1 and CANIFnDA2. 0 DATAB RW 0 Access Data Byte 4 to 7 The function of this bit depends on the configuration of the WRNRD bit as follows: Value Description 0 Data bytes 4-7 are unchanged. 1 If WRNRD is clear, transfer data bytes 4-7 in CANIFnDA1 and CANIFnDA2 to the message object. If WRNRD is set, transfer data bytes 4-7 in message object to CANIFnDA1 and CANIFnDA2. 1392 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 12: CAN IF1 Mask 1 (CANIF1MSK1), offset 0x028 Register 13: CAN IF2 Mask 1 (CANIF2MSK1), offset 0x088 The mask information provided in this register accompanies the data (CANIFnDAn), arbitration information (CANIFnARBn), and control information (CANIFnMCTL) to the message object in the message RAM. The mask is used with the ID bit in the CANIFnARBn register for acceptance filtering. Additional mask information is contained in the CANIFnMSK2 register. CAN IFn Mask 1 (CANIFnMSK1) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x028 Type RW, reset 0x0000.FFFF 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 reserved Type Reset MSK Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 MSK RW 0xFFFF Identifier Mask When using a 29-bit identifier, these bits are used for bits [15:0] of the ID. The MSK field in the CANIFnMSK2 register are used for bits [28:16] of the ID. When using an 11-bit identifier, these bits are ignored. Value Description 0 The corresponding identifier field (ID) in the message object cannot inhibit the match in acceptance filtering. 1 The corresponding identifier field (ID) is used for acceptance filtering. June 18, 2014 1393 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 14: CAN IF1 Mask 2 (CANIF1MSK2), offset 0x02C Register 15: CAN IF2 Mask 2 (CANIF2MSK2), offset 0x08C This register holds extended mask information that accompanies the CANIFnMSK1 register. CAN IFn Mask 2 (CANIFnMSK2) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x02C Type RW, reset 0x0000.FFFF 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 MXTD MDIR reserved RW 1 RW 1 RO 1 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 RW 1 reserved Type Reset Type Reset MSK Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 MXTD RW 1 14 13 MDIR reserved RW RO 1 1 RW 1 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Mask Extended Identifier Value Description 0 The extended identifier bit (XTD in the CANIFnARB2 register) has no effect on the acceptance filtering. 1 The extended identifier bit XTD is used for acceptance filtering. Mask Message Direction Value Description 0 The message direction bit (DIR in the CANIFnARB2 register) has no effect for acceptance filtering. 1 The message direction bit DIR is used for acceptance filtering. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1394 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset Description 12:0 MSK RW 0xFF Identifier Mask When using a 29-bit identifier, these bits are used for bits [28:16] of the ID. The MSK field in the CANIFnMSK1 register are used for bits [15:0] of the ID. When using an 11-bit identifier, MSK[12:2] are used for bits [10:0] of the ID. Value Description 0 The corresponding identifier field (ID) in the message object cannot inhibit the match in acceptance filtering. 1 The corresponding identifier field (ID) is used for acceptance filtering. June 18, 2014 1395 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 16: CAN IF1 Arbitration 1 (CANIF1ARB1), offset 0x030 Register 17: CAN IF2 Arbitration 1 (CANIF2ARB1), offset 0x090 These registers hold the identifiers for acceptance filtering. CAN IFn Arbitration 1 (CANIFnARB1) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x030 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset ID Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 ID RW 0x0000 Message Identifier This bit field is used with the ID field in the CANIFnARB2 register to create the message identifier. When using a 29-bit identifier, bits 15:0 of the CANIFnARB1 register are [15:0] of the ID, while bits 12:0 of the CANIFnARB2 register are [28:16] of the ID. When using an 11-bit identifier, these bits are not used. 1396 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 18: CAN IF1 Arbitration 2 (CANIF1ARB2), offset 0x034 Register 19: CAN IF2 Arbitration 2 (CANIF2ARB2), offset 0x094 These registers hold information for acceptance filtering. CAN IFn Arbitration 2 (CANIFnARB2) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x034 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 MSGVAL XTD DIR RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset Type Reset ID Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 MSGVAL RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Message Valid Value Description 0 The message object is ignored by the message handler. 1 The message object is configured and ready to be considered by the message handler within the CAN controller. All unused message objects should have this bit cleared during initialization and before clearing the INIT bit in the CANCTL register. The MSGVAL bit must also be cleared before any of the following bits are modified or if the message object is no longer required: the ID fields in the CANIFnARBn registers, the XTD and DIR bits in the CANIFnARB2 register, or the DLC field in the CANIFnMCTL register. 14 XTD RW 0 Extended Identifier Value Description 0 An 11-bit Standard Identifier is used for this message object. 1 A 29-bit Extended Identifier is used for this message object. June 18, 2014 1397 Texas Instruments-Production Data Controller Area Network (CAN) Module Bit/Field Name Type Reset 13 DIR RW 0 12:0 ID RW 0x000 Description Message Direction Value Description 0 Receive. When the TXRQST bit in the CANIFnMCTL register is set, a remote frame with the identifier of this message object is received. On reception of a data frame with matching identifier, that message is stored in this message object. 1 Transmit. When the TXRQST bit in the CANIFnMCTL register is set, the respective message object is transmitted as a data frame. On reception of a remote frame with matching identifier, the TXRQST bit of this message object is set (if RMTEN=1). Message Identifier This bit field is used with the ID field in the CANIFnARB2 register to create the message identifier. When using a 29-bit identifier, ID[15:0] of the CANIFnARB1 register are [15:0] of the ID, while these bits, ID[12:0], are [28:16] of the ID. When using an 11-bit identifier, ID[12:2] are used for bits [10:0] of the ID. The ID field in the CANIFnARB1 register is ignored. 1398 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 20: CAN IF1 Message Control (CANIF1MCTL), offset 0x038 Register 21: CAN IF2 Message Control (CANIF2MCTL), offset 0x098 This register holds the control information associated with the message object to be sent to the Message RAM. CAN IFn Message Control (CANIFnMCTL) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x038 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 UMASK TXIE RXIE RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RMTEN TXRQST EOB RW 0 RW 0 RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset NEWDAT MSGLST INTPND Type Reset RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:16 reserved RO 0x0000 15 NEWDAT RW 0 14 MSGLST RW 0 reserved RO 0 RO 0 DLC Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. New Data Value Description 0 No new data has been written into the data portion of this message object by the message handler since the last time this flag was cleared by the CPU. 1 The message handler or the CPU has written new data into the data portion of this message object. Message Lost Value Description 0 No message was lost since the last time this bit was cleared by the CPU. 1 The message handler stored a new message into this object when NEWDAT was set; the CPU has lost a message. This bit is only valid for message objects when the DIR bit in the CANIFnARB2 register is clear (receive). 13 INTPND RW 0 Interrupt Pending Value Description 0 This message object is not the source of an interrupt. 1 This message object is the source of an interrupt. The interrupt identifier in the CANINT register points to this message object if there is not another interrupt source with a higher priority. June 18, 2014 1399 Texas Instruments-Production Data Controller Area Network (CAN) Module Bit/Field Name Type Reset 12 UMASK RW 0 11 10 9 8 TXIE RXIE RMTEN TXRQST RW RW RW RW 0 0 0 0 Description Use Acceptance Mask Value Description 0 Mask is ignored. 1 Use mask (MSK, MXTD, and MDIR bits in the CANIFnMSKn registers) for acceptance filtering. Transmit Interrupt Enable Value Description 0 The INTPND bit in the CANIFnMCTL register is unchanged after a successful transmission of a frame. 1 The INTPND bit in the CANIFnMCTL register is set after a successful transmission of a frame. Receive Interrupt Enable Value Description 0 The INTPND bit in the CANIFnMCTL register is unchanged after a successful reception of a frame. 1 The INTPND bit in the CANIFnMCTL register is set after a successful reception of a frame. Remote Enable Value Description 0 At the reception of a remote frame, the TXRQST bit in the CANIFnMCTL register is left unchanged. 1 At the reception of a remote frame, the TXRQST bit in the CANIFnMCTL register is set. Transmit Request Value Description 0 This message object is not waiting for transmission. 1 The transmission of this message object is requested and is not yet done. Note: If the WRNRD and TXRQST bits in the CANIFnCMSK register are set, this bit is ignored. 1400 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 7 EOB RW 0 Description End of Buffer Value Description 0 Message object belongs to a FIFO Buffer and is not the last message object of that FIFO Buffer. 1 Single message object or last message object of a FIFO Buffer. This bit is used to concatenate two or more message objects (up to 32) to build a FIFO buffer. For a single message object (thus not belonging to a FIFO buffer), this bit must be set. 6:4 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3:0 DLC RW 0x0 Data Length Code Value Description 0x0-0x8 Specifies the number of bytes in the data frame. 0x9-0xF Defaults to a data frame with 8 bytes. The DLC field in the CANIFnMCTL register of a message object must be defined the same as in all the corresponding objects with the same identifier at other nodes. When the message handler stores a data frame, it writes DLC to the value given by the received message. June 18, 2014 1401 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 22: CAN IF1 Data A1 (CANIF1DA1), offset 0x03C Register 23: CAN IF1 Data A2 (CANIF1DA2), offset 0x040 Register 24: CAN IF1 Data B1 (CANIF1DB1), offset 0x044 Register 25: CAN IF1 Data B2 (CANIF1DB2), offset 0x048 Register 26: CAN IF2 Data A1 (CANIF2DA1), offset 0x09C Register 27: CAN IF2 Data A2 (CANIF2DA2), offset 0x0A0 Register 28: CAN IF2 Data B1 (CANIF2DB1), offset 0x0A4 Register 29: CAN IF2 Data B2 (CANIF2DB2), offset 0x0A8 These registers contain the data to be sent or that has been received. In a CAN data frame, data byte 0 is the first byte to be transmitted or received and data byte 7 is the last byte to be transmitted or received. In CAN's serial bit stream, the MSB of each byte is transmitted first. CAN IFn Data nn (CANIFnDnn) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x03C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset DATA Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 DATA RW 0x0000 Data The CANIFnDA1 registers contain data bytes 1 and 0; CANIFnDA2 data bytes 3 and 2; CANIFnDB1 data bytes 5 and 4; and CANIFnDB2 data bytes 7 and 6. 1402 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 30: CAN Transmission Request 1 (CANTXRQ1), offset 0x100 Register 31: CAN Transmission Request 2 (CANTXRQ2), offset 0x104 The CANTXRQ1 and CANTXRQ2 registers hold the TXRQST bits of the 32 message objects. By reading out these bits, the CPU can check which message object has a transmission request pending. The TXRQST bit of a specific message object can be changed by three sources: (1) the CPU via the CANIFnMCTL register, (2) the message handler state machine after the reception of a remote frame, or (3) the message handler state machine after a successful transmission. The CANTXRQ1 register contains the TXRQST bits of the first 16 message objects in the message RAM; the CANTXRQ2 register contains the TXRQST bits of the second 16 message objects. CAN Transmission Request n (CANTXRQn) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x100 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 TXRQST Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 TXRQST RO 0x0000 Transmission Request Bits Value Description 0 The corresponding message object is not waiting for transmission. 1 The transmission of the corresponding message object is requested and is not yet done. June 18, 2014 1403 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 32: CAN New Data 1 (CANNWDA1), offset 0x120 Register 33: CAN New Data 2 (CANNWDA2), offset 0x124 The CANNWDA1 and CANNWDA2 registers hold the NEWDAT bits of the 32 message objects. By reading these bits, the CPU can check which message object has its data portion updated. The NEWDAT bit of a specific message object can be changed by three sources: (1) the CPU via the CANIFnMCTL register, (2) the message handler state machine after the reception of a data frame, or (3) the message handler state machine after a successful transmission. The CANNWDA1 register contains the NEWDAT bits of the first 16 message objects in the message RAM; the CANNWDA2 register contains the NEWDAT bits of the second 16 message objects. CAN New Data n (CANNWDAn) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x120 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 NEWDAT Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 NEWDAT RO 0x0000 New Data Bits Value Description 0 No new data has been written into the data portion of the corresponding message object by the message handler since the last time this flag was cleared by the CPU. 1 The message handler or the CPU has written new data into the data portion of the corresponding message object. 1404 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 34: CAN Message 1 Interrupt Pending (CANMSG1INT), offset 0x140 Register 35: CAN Message 2 Interrupt Pending (CANMSG2INT), offset 0x144 The CANMSG1INT and CANMSG2INT registers hold the INTPND bits of the 32 message objects. By reading these bits, the CPU can check which message object has an interrupt pending. The INTPND bit of a specific message object can be changed through two sources: (1) the CPU via the CANIFnMCTL register, or (2) the message handler state machine after the reception or transmission of a frame. This field is also encoded in the CANINT register. The CANMSG1INT register contains the INTPND bits of the first 16 message objects in the message RAM; the CANMSG2INT register contains the INTPND bits of the second 16 message objects. CAN Message n Interrupt Pending (CANMSGnINT) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x140 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset INTPND Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 INTPND RO 0x0000 Interrupt Pending Bits Value Description 0 The corresponding message object is not the source of an interrupt. 1 The corresponding message object is the source of an interrupt. June 18, 2014 1405 Texas Instruments-Production Data Controller Area Network (CAN) Module Register 36: CAN Message 1 Valid (CANMSG1VAL), offset 0x160 Register 37: CAN Message 2 Valid (CANMSG2VAL), offset 0x164 The CANMSG1VAL and CANMSG2VAL registers hold the MSGVAL bits of the 32 message objects. By reading these bits, the CPU can check which message object is valid. The message valid bit of a specific message object can be changed with the CANIFnARB2 register. The CANMSG1VAL register contains the MSGVAL bits of the first 16 message objects in the message RAM; the CANMSG2VAL register contains the MSGVAL bits of the second 16 message objects in the message RAM. CAN Message n Valid (CANMSGnVAL) CAN0 base: 0x4004.0000 CAN1 base: 0x4004.1000 Offset 0x160 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 MSGVAL Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 MSGVAL RO 0x0000 Message Valid Bits Value Description 0 The corresponding message object is not configured and is ignored by the message handler. 1 The corresponding message object is configured and should be considered by the message handler. 1406 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 20 Ethernet Controller The Ethernet Controller has the following features: ■ Conforms to the IEEE 802.3 specification – 10BASE-T/100BASE-TX IEEE-802.3 compliant – Supports 10/100 Mbps data transmission rates – Supports full-duplex and half-duplex (CSMA/CD) operation – Supports flow control and back pressure – Full-featured and enhanced auto-negotiation – Supports IEEE 802.1Q VLAN tag detection ■ Conforms to IEEE 1588-2002 Timestamp Precision Time Protocol (PTP) protocol and the IEEE 1588-2008 Advanced Timestamp specification – Transmit and Receive frame time stamping – Precision Time Protocol – Flexible pulse per second output – Supports coarse and fine correction methods ■ Multiple addressing modes – Four MAC address filters – Programmable 64-bit Hash Filter for multicast address filtering – Promiscuous mode support ■ Processor offloading – Programmable insertion (TX) or deletion (RX) of preamble and start-of-frame data – Programmable generation (TX) or deletion (RX) of CRC and pad data – IP header and hardware checksum checking (IPv4, IPv6, TCP/UDP/ICMP) ■ Highly configurable – LED activity selection – Supports network statistics with RMON/MIB counters – Supports Magic Packet and wakeup frames ■ Efficient transfers using integrated Direct Memory Access (DMA) – Dual-buffer (ring) or linked-list (chained) descriptors June 18, 2014 1407 Texas Instruments-Production Data Ethernet Controller – Round-robin or fixed priority arbitration between TX/RX – Descriptors support up to 8 kB transfer blocks size – Programmable interrupts for flexible system implementation ■ Physical media manipulation – MDI/MDI-X cross-over support – Register-programmable transmit amplitude – Automatic polarity correction and 10BASE-T signal reception 20.1 Block Diagram Figure 20-1 on page 1408 shows the block diagram of the Ethernet MAC with an integrated PHY interface: To Bus Matrix AHB Master Interface Figure 20-1. Ethernet MAC with Integrated PHY Interface TX FIFO DMA Controller TX/RX Controller IEEE 1588 TX Module 2002 / 2008 / PPS CRC Offload Engine RX Module Filtering / VLAN / SA / CRC CRC TX Pair Physical Layer Interface (PHY) RX Pair RX FIFO To Bus Matrix 20.2 AHB Slave Interface MEDIA ACCESS CONTROLLER (MAC) EN0MDC DMA Control / Status Registers MAC Control / Status Registers Serial Management Interface (SMI) Power Management Module (PMM) MAC Management Counters (MMC) EN0MDIO Signal Description The following table lists the external signals of the Ethernet Controller and describes the function of each. Some of the Ethernet signals have dedicated functions while the others listed in the table are alternate functions for GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible GPIO pin placements for these Ethernet module signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to assign the Ethernet signals. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the Ethernet signal to the specified GPIO port pin. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. The remaining signals (with the word "fixed" in the Pin Mux/Pin Assignment column) have a fixed pin assignment and function. 1408 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 20-1. Ethernet Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description EN0LED0 42 63 PF0 (5) PK4 (5) O TTL Ethernet 0 LED 0. EN0LED1 46 61 PF4 (5) PK6 (5) O TTL Ethernet 0 LED 1. EN0LED2 43 62 PF1 (5) PK5 (5) O TTL Ethernet 0 LED 2. EN0PPS 49 116 PG0 (5) PJ0 (5) O TTL Ethernet 0 Pulse-Per-Second (PPS) Output. EN0RXIN 53 fixed I/O TTL Ethernet PHY negative receive differential input. EN0RXIP 54 fixed I/O TTL Ethernet PHY positive receive differential input. EN0TXON 56 fixed I/O TTL Ethernet PHY negative transmit differential output. EN0TXOP 57 fixed I/O TTL Ethernet PHY positive transmit differential output. RBIAS 59 fixed O Analog 4.87-kΩ resistor (1% precision) for Ethernet PHY. 20.3 Functional Description The Ethernet Controller is made up of the following sub-modules: ■ Clock Control ■ DMA Controller ■ Transmit/Receive Controller (TX/RX Controller) ■ Media Access Controller (MAC) ■ AHB Bus Interface ■ PHY Interface The following sections describe the features and functions of each sub-module. 20.3.1 Ethernet Clock Control 20.3.1.1 PHY Interface The Ethernet Controller Module and Integrated PHY receive two clock inputs: ■ A gated system clock acts as the clock source to the Control and Status registers (CSR) of the Ethernet MAC. The SYSCLK frequency for Run, Sleep and Deep Sleep mode is programmed in the System Control module. Refer to “System Control” on page 220 for more information on programming SYSCLK and enabling the Ethernet MAC. ■ The PHY receives the main oscillator (MOSC) which must be 25 MHz ± 50 ppm for proper operation. The MOSC source can be a single-ended source or a crystal. Figure 20-2 on page 1410 shows the clock inputs to the Ethernet Controller Module. June 18, 2014 1409 Texas Instruments-Production Data Ethernet Controller Figure 20-2. Ethernet MAC and PHY Clock Structure Tiva Cortex-M4 Microcontroller Ethernet MAC Internal PHY TX EN0TXOP EN0TXON EN0RXIP Gated SYSCLK PTPCEN MAC Control / Status Registers EMACCC RX EN0INTRN EN0RXIN RBIAS EN0MDC EN0LED0 EN0MDIO EN0LED1 PTP_REFCLK EN0LED2 MOSC 25 MHz 20.3.2 DMA Controller The Ethernet Controller's integrated DMA is used to optimize data transfer between the MAC and system SRAM memory. The DMA has independent transmit and receive engines. The DMA transmit engine transfers data from system memory to the Ethernet TX/RX Controller, while the receive engine transfers data from the RX FIFO to the system memory. The controller uses descriptors to efficiently move data from source to destination with minimal CPU intervention. The DMA is designed for packet-oriented data transfers such as frames in Ethernet. Fixed burst lengths of 1, 4, 8, or 16 words are supported along with re-initiation of bursts when retry or burst termination responses occur. For a burst retry, if the remaining address count is greater than 1 and the RIB bit in the Ethernet MAC DMA Bus Mode (EMACDMABUSMOD) register is clear, then the transfer resends data in one continuous burst. When one transfer is left, it is done as a single burst and the transaction is terminated immediately afterward. If the RIB bit in the EMACDMABUSMOD register is set, the DMA sends the remaining data in fixed burst sizes of 1, 4, 8, or 16 words. The application may also choose between solely fixed bursts or mixed bursts by the DMA. If the MB bit is set and the FB bit is clear in the EMACDMABUSMOD register, then the DMA uses fixed bursts for burst sizes less than 16 and a full, non-divided burst for lengths greater than 16. Fixed burst lengths allow for more DMA bus arbitration with other masters. Maximum burst transfer lengths can be programmed for both the receive and transmit channels of the DMA through the PBL, RPBL and 8xPBL bit fields in the EMACDMABUSMOD register. The DMA Controller requests a read transfer only when it can accept the received burst data completely. Data read from the bus is always pushed into the DMA without any delay or busy cycles. The DMA requests write transfers only when it has sufficient data to transfer the burst completely. When operating in fixed burst length mode, the DMA interface continues to burst with dummy data 1410 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller until the specified length is completed. The Ethernet controller can be programmed to interrupt the CPU in situations such as Frame Transmit and Receive transfer completion, and other normal/error conditions. The integrated Ethernet DMA communicates through two data structures: ■ Control and Status registers ■ Descriptor lists and data buffers. The DMA writes data frames received by the MAC to the receive buffer in system memory and transfers data frames for transmission from system memory to the MAC. Descriptors that reside in the system memory act as pointers to these buffers. There are two descriptor lists: one for reception and one for transmission. The base address of each list is written into the Ethernet MAC Receive Descriptor List Address (EMACRXDLADDR) register at offset 0xC0C and the Ethernet Mac Transmit Descriptor List Address (EMACTXDLADDR) register at offset 0xC10, respectively. The descriptor structure can contain up to 8 words (32 bytes). These are described in more detail in “Enhanced and Alternate Descriptors” on page 1413. A descriptor list is forward linked (either implicitly or explicitly). The last descriptor may point back to the first entry to create a ring structure. Explicit chaining of descriptors is accomplished by enabling second address chaining in both the Receive and Transmit descriptors (RDES0[14] and TDES0[20]). The descriptor lists reside in the SRAM memory address space. Each descriptor can point to a maximum of two buffers. This enables two buffers to be used at different physical addresses rather than contiguous buffers in memory. The data buffer also resides in the physical memory space and consists of an entire frame or part of a frame, but cannot exceed a single frame. Buffers contain only data and buffer status is maintained in the descriptor. Data chaining refers to frames that span multiple data buffers. However, a single descriptor cannot span multiple frames. The DMA skips to the next frame buffer when the end-of-frame is detected. Data chaining can be enabled or disabled through the descriptors. Note: 20.3.2.1 The EMAC DMA Controller only has access to internal system SRAM memory. Burst Access The DMA attempts to execute fixed length Burst transfers if the FB bit is set in the EMACDMABUSMOD register. The maximum burst length is indicated and limited by the PBL field in the EMACDMABUSMOD register. The Receive and Transmit descriptors are always accessed in the maximum possible (limited by PBL) burst-size for the bytes to be read. The TX DMA initiates a transfer only when there is sufficient space in the FIFO to accommodate the configured burst or remaining bytes of the end of a frame. When the DMA is configured for fixed-length burst, it transfers data using the best combination of fixed burst sizes of 4, 8, or 16 and single transactions. Otherwise when the FB bit is clear in the EMACDMABUSMOD register, the DMA transfers data as a continuous undefined burst and single transactions. The RX DMA initiates a data transfer only when sufficient data to accommodate the configured burst is available in RX FIFO or when the end-of-frame (when it is less than the configured burst length) is detected in the RX FIFO. The DMA indicates the start address and the number of transfers required to the system. When the FB bit is set in the EMACDMABUSMOD register, then it transfers data using the best combination of fixed burst sizes of 4, 8, or 16 and single transactions. If the end-of frame is reached before the fixed-burst ends, then dummy transfers are performed in order to complete the fixed-burst. Otherwise, if the FB bit is clear, the DMA transfers data using INCR (undefined length) and SINGLE transactions. When the DMA is configured for address-aligned transfers, both DMA engines ensure that the first burst transfer on the system bus is less than or June 18, 2014 1411 Texas Instruments-Production Data Ethernet Controller equal to the size of the configured PBL in the EMACDMABUSMOD register. Thus, all subsequent transfers start at an address that is aligned to the configured PBL. The DMA can only align the address for burst transfers up to size 16 because only bursts of 16 are supported. 20.3.2.2 Data Buffer Alignment The transmit and receive data buffers do not have any restrictions on the start address alignment. For example, in systems with 32-bit memory, the start address for the buffers can be aligned to any of the four bytes. However, the DMA always initiates write transfers, with address aligned to the bus width and dummy data (old data) in the byte lanes that are not valid. This typically happens during the transfer of the beginning or end of an Ethernet frame. The software driver should discard the dummy bytes based on the start address of the buffer and size of the frame. For example, if the transmit buffer address is 0x0000.0FF2, and 15 bytes need to be transferred, then the DMA reads five full words from address 0x0000.0FF0, but when transferring data to the TX FIFO, the extra bytes (the first two bytes) are dropped or ignored. Similarly, the last 3 bytes of the last transfer are also ignored. The DMA always ensures that it transfers a full 32-bit data to the TX FIFO, unless it is the end of frame. If the receive buffer address is 0x0000.0FF2 and 15 bytes of a received frame need to be transferred, then the DMA writes five full words from address 0x0000.0FF0. However, the first two bytes of first transfer and the last three bytes of the fifth transfer have dummy data. The DMA considers the offset address only if it is the first Receive buffer of the frame. The DMA ignores the offset address and performs full word writes for the middle and the last Receive buffer of the frame. 20.3.2.3 Buffer Size Calculations The DMA does not update the size fields in the Transmit and Receive descriptors. The DMA updates only the status fields (RDES and TDES) of the descriptors. The driver has to perform the size calculations. The TX DMA transfers the exact number of bytes (indicated by buffer size fields of TDES1) to the MAC. If a descriptor is marked as first (FS bit of TDES0 is set), then the DMA marks the first transfer from the buffer as the start-of-frame (SOF). If a descriptor is marked as last (LS bit of TDES0), then the DMA marks the last transfer from that data buffer as the end-of frame (EOF). The RX DMA transfers data to a buffer until the buffer is full or the end-of frame is received from the RX/TX Controller. If a descriptor is not marked as last (LS bit of RDES0), then the descriptor's corresponding buffer(s) are full and the amount of valid data in a buffer is accurately indicated by its buffer size field minus the data buffer pointer offset when the FS bit of that descriptor is set. The offset is zero when the data buffer pointer is aligned to the data bus width. If a descriptor is marked as last, then the buffer may not be full (as indicated by the buffer size in RDES1). To compute the amount of valid data in this final buffer, the driver must read the frame length (FL bits of RDES0) and subtract the sum of the buffer sizes of the preceding buffers in this frame. The Receive DMA always transfers the start of next frame with a new descriptor. Note: Even when the start address of a receive buffer is not aligned to the data width of 32-bit system bus, the system should allocate a receive buffer of a size aligned to the system bus width. For example, if the system allocates a 1,024-byte (1 KB) receive buffer starting from address 0x1000, the software can program the buffer start address in the Receive descriptor to have a 0x1002 offset. The Receive DMA writes the frame to this buffer with dummy data in the first two locations (0x1000 and 0x1001). The actual frame is written from location 0x1002. Thus, the actual useful space in this buffer is 1,022 bytes, even though the buffer size is programmed as 1,024 bytes, because of the start address offset. 1412 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 20.3.2.4 DMA Arbiter The arbiter inside the DMA module performs the arbitration between the Transmit and Receive channel accesses. The DMA can be configured to arbitrate in a round-robin or fixed-priority configuration. When the DA bit of the EMACDMABUSMOD register is clear, the DMA arbiter allocates the data bus in the ratio set by the PR bit field of the EMACDMABUSMOD register when both the TX and RX DMA request access at the same time. When the DA bit is set, the RX DMA always has priority over the TX DMA for data access by default. However if the TXPR bit of the EMACDMABUSMOD register is also set, then the TX DMA always gets priority over the RX DMA. 20.3.2.5 Enhanced and Alternate Descriptors Enhanced Descriptors can contain up to eight words (32 bytes) and buffers of up to 8 KB (useful for Jumbo frames). Enhanced Descriptors support IEEE 1588-2008 Advanced Timestamp and IPC Full Checksum (Type 2) Offload. These enhanced features are enabled with the TSEN bit of the EMACTIMSTCTRL register and the IPC bit of the EMACCFG register, respectively. When using Enhanced Descriptors, set the descriptor size to eight words with the Alternate Descriptor Size (ATDS) bit in the Ethernet MAC DMA Bus Mode (EMACDMABUSMOD) register. If these enhanced features are not enabled, the extended descriptors (DES4 to DES7) are not required. Therefore, the software can use Alternate Descriptors with a default size of 16 bytes (4 words). For alternate descriptors, the software should clear the Alternate Descriptor Size (ATDS) bit in the Ethernet MAC DMA Bus Mode (EMACDMABUSMOD) register. See the section called “Enhanced Transmit Descriptor” on page 1413 and the section called “Enhanced Receive Descriptor” on page 1418 for more details on the descriptor structure. Enhanced Transmit Descriptor The MAC requires at least one descriptor for a transmit frame. In addition to two buffers, two byte-count buffers, and two address pointers, the transmit descriptor has control fields which can be used to control the MAC operation on per-transmit frame basis. Figure 20-3 on page 1414 shows the enhanced transmit descriptor. Software must program the control bits TDES0[31:18] during descriptor initialization. When the DMA updates the descriptor, it writes back all the control bits to their initialized value, clears the OWN bit and updates the status bits. With advanced timestamp support, the snapshot of the timestamp to be taken can be enabled for a given frame by setting Bit 25 (TTSE) of TDES0. When the descriptor is closed (that is, when the OWN bit is cleared), the timestamp is written into TDES6 and TDES7. Note: When the Advanced Timestamp feature is enabled, software should set the ATDS bit of the Ethernet MAC DMA Bus Mode (EMACDMABUSMOD) register, offset 0xC00, so that the DMA operates with extended descriptor size. When this control bit is reset to the default (0), the TDES4-TDES7 descriptor space is not valid and only Alternate Descriptors are available, with a default size of 16 bytes (4 words). June 18, 2014 1413 Texas Instruments-Production Data Ethernet Controller Figure 20-3. Enhanced Transmit Descriptor Structure 31 23 T CTRL T TDES0 OWN [30:26] S E TDES1 CTRL [31:29] 15 CTRL [24:18] T T S S Status [16:7] Byte Count Buffer2 [28:16] Reserved 0 CTRL/ Status [6:3] Status [2:0] Byte Count Buffer 1 [12:0] Buffer1 Address [31:0] TDES2 TDES3 7 Buffer2 Address [31:0]/Next Descriptor Address [31:0] TDES4 Reserved TDES5 Reserved TDES6 Transmit Timestamp Low [31:0] TDES7 Transmit Timestamp High [31:0] The following tables define the Enhanced Transmit Descriptors. Transmit Descriptor 0 (TDES0) contains the transmitted frame status and the descriptor ownership information. TDES1 contains the buffer sizes and other bits which control the descriptor chain or ring and the frame being transferred. TDES2 contains the address pointer to the first buffer of the descriptor. TDES3 contains the address pointer either to the second buffer of the descriptor or the next descriptor. TDES6 and TDES7 contain the timestamp. Table 20-2. Enhanced Transmit Descriptor 0 (TDES0) Bit 31 Description OWN: Own Bit When set, this bit indicates that the descriptor is owned by the DMA. When this bit is reset, it indicates that the descriptor is owned by the Host. The DMA clears this bit either when it completes the frame transmission or when the buffers allocated in the descriptor are empty. The ownership bit of the First Descriptor of the frame should be set after all subsequent descriptors belonging to the same frame have been set. This avoids a possible race condition between fetching a descriptor and the driver setting an ownership bit. 30 IC: Interrupt on Completion When set this bit sets the Transmit Interrupt (TI) bit in the EMACDMARIS register when the frame contained in this descriptor has been transmitted. 1414 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 20-2. Enhanced Transmit Descriptor 0 (TDES0) (continued) Bit 29 Description LS: Last Segment When set, this bit indicates that the buffer contains the last segment of the frame. When this bit is set, the TBS1 or TBS2 field in TDES1 should have a non-zero value. 28 FS: First Segment When set, this bit indicates that the buffer contains the first segment of a frame. 27 DC: Disable CRC When set, the MAC does not append a Cyclic Redundancy Check (CRC) to the end of the transmitted frame. This is valid only when the first segment (TDES0[28]) is set. 26 DP: Disable Padding When set, the MAC does not automatically add padding to a frame shorter than 64 bytes. When this bit is reset, the DMA automatically adds padding and CRC to a frame shorter than 64 bytes, and the CRC field is added despite the state of the DC (TDES0[27]) bit. This is valid only when the first segment (TDES0[28]) is set. 25 TTSE: Transmit Timestamp Enable When set, this bit enables IEEE1588 hardware timestamping for the transmit frame referenced by the descriptor. This bit is only valid when the First Segment Control bit (TDES0[28] is set. 24 CRCR: CRC Replacement Control When set, the MAC replaces the last four bytes of the transmitted packet with recalculated CRC bytes. The CPU should ensure that the CRC bytes are present in the frame being transferred from the Transmit Buffer. CRC replacement is done only when Bit 27 (DC) is set to 1. 23:22 CIC: Checksum Insertion Control These bits control the insertion of checksums in Ethernet frames that encapsulate TCP, UDP, or ICMP over IPv4 or IPv6. This field is valid when the First Segment control bit (TDES0[28]) is set. ■ 0x0 = Do nothing. Checksum Engine bypassed. ■ 0x1 = Insert IPv4 header checksum. Use this value to insert IPv4 header checksum when the frame encapsulates an IPv4 datagram. ■ 0x2 = Insert TCP/UDP/ICMP checksum. The checksum is calculated over the TCP, UDP, or ICMP segment only and the TCP, UDP, or ICMP pseudo-header checksum is assumed to be present in the corresponding input frame's Checksum field. An IPv4 header checksum is also inserted if the encapsulated datagram conforms to IPv4. ■ 0x3 = Insert a TCP/UDP/ICMP checksum that is fully calculated in this engine. The TCP, UDP, or ICMP pseudo-header is included in the checksum calculation, and the input frame's corresponding Checksum field has an all-zero value. An IPv4 Header checksum is also inserted if the encapsulated datagram conforms to IPv4. The Checksum engine detects whether the TCP, UDP, or ICMP segment is encapsulated in IPv4 or IPv6 and processes its data accordingly. 21 TER: Transmit End of Ring When set, this bit indicates that the descriptor list reached its final descriptor. The DMA returns to the base address of the list, creating a descriptor ring. 20 TCH: Second Address Chained When set, this bit indicates that the second address in the descriptor is the Next Descriptor address rather than the second buffer address. When TDES0[20] is set, TBS2 (TDES1[28:16]) is a "don’t care" value. TDES0[21] takes precedence over TDES0[20]. June 18, 2014 1415 Texas Instruments-Production Data Ethernet Controller Table 20-2. Enhanced Transmit Descriptor 0 (TDES0) (continued) Bit 19:18 Description VLIC: VLAN Insertion Control When set, these bits request the MAC to perform VLAN tagging or untagging before transmitting the frames. If the frame is modified for VLAN tags, the MAC automatically recalculates and replaces the CRC bytes. The values of this field are as follows: 17 ■ 0x0= Do not add a VLAN tag ■ 0x1= Remove the VLAN tag from the frames before transmission. ■ 0x2= Insert a VLAN tag with the tag value programmed in the Ethernet MAC VLAN Tag Inclusion or Replacement (EMACVLNINCREP) register, offset 0x584. ■ 0x3= Replace the VLAN tag in frame with the tag value programmed in the EMACVLNINCREP register. This field is valid when the First Segment control bit (TDES0[28]) is set. TTSS:TX Timestamp This status bit indicates that a timestamp has been captured for the corresponding transmit frame. When this bit is set, TDES6 and TDES7 have timestamp values that were captured for the transmit frame. This field is valid only when the Last Segment control bit (TDES0[29]) in a descriptor is set. 16 IHE: IP Header Error When set, this bit indicates that the Checksum Offload engine detected an IP header error. This bit is valid only when TX Checksum Offload is enabled. Otherwise, it is reserved. If the Checksum Offload Engine detects an IP header error, it still inserts an IPv4 header checksum if the Ethernet Type field indicates an IPv4 payload. 15 ES: Error Summary Indicates the logical OR of the following bits: 14 ■ TDES0[16]: IP Header Error ■ TDES0[14]: Jabber Timeout ■ TDES0[13]: Frame Flush ■ TDES0[12]: Payload Checksum Error ■ TDES0[11]: Loss of Carrier ■ TDES0[10]: No Carrier ■ TDES0[9]: Late Collision ■ TDES0[8]: Excessive Collision ■ TDES0[2]: Excessive Deferral ■ TDES0[1]: Underflow error JT: Jabber Timeout When set, this bit indicates that the MAC transmitter has experienced a jabber timeout. This bit can only be set when the Jabber Disabled (JD) bit of the EMACCFG register is clear. 13 FF: Frame Flushed When set, this bit indicates that the DMA flushed the frame because of a software flush command given by the CPU. 12 IPE: IP Payload Error When set, this bit indicates that MAC transmitter detected an error in the TCP, UDP, or ICMP IP datagram payload. The transmitter checks the payload length received in the IPv4 or IPv6 header against the actual number of TCP, UDP, or ICMP packet bytes received from the application and issues an error status in case of a mismatch. 1416 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 20-2. Enhanced Transmit Descriptor 0 (TDES0) (continued) Bit 11 Description LC: Loss of Carrier When set, this bit indicates that Loss of Carrier occurred during frame transmission. This is valid only for the frames transmitted without collision and when the MAC operates in half-duplex mode. 10 NC: No Carrier When set, this bit indicates that the carrier sense signal form the PHY was not asserted during transmission. 9 LC: Late Collision When set, this bit indicates that frame transmission was aborted due to a collision occurring after the collision window (64 byte times including Preamble in MII Mode). Not valid if Underflow Error (bit 1) is set. 8 Excessive Collision When set, this bit indicates that the transmission was aborted after 16 successive collisions while attempting to transmit the current frame. If the Disable Retry (DR) bit in EMACCFG register is set, this bit is set after the first collision and the transmission of the frame is aborted. 7 VF: VLAN Frame When set, this bit indicates that the transmitted frame was a VLAN-type frame. 6:3 CC: Collision Count This 4-bit counter value indicates the number of collisions occurring before the frame was transmitted. The count is not valid when the Excessive Collision bit (TDES0[8]) is set. 2 ED: Excessive Deferral When set, this bit indicates that the transmission has ended because of excessive deferral of over 24,288 bit times (155,680 bits times when Jumbo Frame is enabled). This bit is dependent on the Deferral Check (DC) bit being enabled in the EMACCFG register. 1 UF: Underflow Error When set, this bit indicates that the MAC aborted the frame because the data arrived late from system memory. Underflow Error indicates that the DMA encountered an empty Transmit Buffer while transmitting the frame. The transmission process enters the suspended state and sets both Transmit Underflow (UNF) and Transmit Interrupt (TI) bit in the EMACDMARIS register. 0 DB: Deferred Bit This bit indicates the deferral mechanism is active and that the transmit state machine sends a JAM pattern to defer reception when it senses a carrier before a normal transmission is scheduled. This bit is only valid in half-duplex mode. Table 20-3. Enhanced Transmit Descriptor 1 (TDES1) Bit 31:29 Description SAIC: SA Insertion Control These bits request the MAC to add or replace the Source Address field in the Ethernet frame with the value given in the MAC Address 0 register. If the Source Address field is modified in a frame, the MAC automatically recalculates and replaces the CRC bytes. The Bit 31 specifies the MAC Address Register (1 or 0) value that is used for Source Address insertion or replacement. The following list describes the values of Bits[30:29]: ■ 0x0= Do not include the source address. ■ 0x1= Insert the source address. For reliable transmission, the application must provide frames without source addresses. ■ 0x2= Replace the source address. For reliable transmission, the application must provide frames with source addresses. ■ 0x3= Reserved These bits are valid when the First Segment control bit (TDES0[28]) is set. June 18, 2014 1417 Texas Instruments-Production Data Ethernet Controller Table 20-3. Enhanced Transmit Descriptor 1 (TDES1) (continued) Bit Description 28:16 TBS2: Transmit Buffer 2 Size This field indicates the second data buffer size in bytes. This field is not valid if TDES0[20] is set. 15:13 Reserved 12:0 TBS1: Transmit Buffer 1 Size These bits indicate the first data buffer byte size, in bytes. If this field is 0, the DMA ignores this buffer and uses Buffer 2 or the next descriptor, depending on the value of TCH (TDES0[20]). Table 20-4. Enhanced Transmit Descriptor 2 (TDES2) Bit 31:0 Description Buffer 1 Address Pointer These bits indicate the physical address of Buffer 1. There is no limitation on the buffer address alignment. Note that the buffers are stored in SRAM. Table 20-5. Enhanced Transmit Descriptor 3 (TDES3) Bit 31:0 Description Buffer 2 Address Pointer (Next Descriptor Address) Indicates the physical address of Buffer 2 when a descriptor ring structure is used. If the Second Address Chained (TDES0[20]) bit is set, this address contains the pointer to the physical memory where the Next Descriptor is present. The buffer address pointer must be aligned to the bus width only when TDES0[20] is set. Note that the buffers are stored in SRAM. Table 20-6. Enhanced Transmit Descriptor 6 (TDES6) Bit 31:0 Description TTSL: Transmit Frame Timestamp Low This field is updated by DMA with the least significant 32 bits of the timestamp captured for the corresponding transmit frame. This field has the timestamp only if the Last Segment bit (LS), TDES0[29], in the descriptor is set and Timestamp status (TTSS) bit, TDES0[17], is set. Table 20-7. Enhanced Transmit Descriptor 7 (TDES7) Bit 31:0 Description TTSH: Transmit Frame Timestamp High This field is updated by DMA with the most significant 32 bits of the timestamp captured for the corresponding receive frame. This field has the timestamp only if the Last Segment bit (LS), TDES0[29], in the descriptor is set and Timestamp status (TTSS) bit , TDES0[17], is set. Enhanced Receive Descriptor The DMA requires at least two descriptors when receiving a frame. The DMA always attempts to acquire an extra descriptor in anticipation of an incoming frame. Before the DMA closes a descriptor, it attempts to acquire the next descriptor even if no frames are received. In a single descriptor (receive) system, the subsystem generates a descriptor error if the receive buffer is unable to accommodate the incoming frame and the next descriptor is not owned by the DMA. Figure 20-4 on page 1419 shows the enhanced receive descriptor. This descriptor is used when Advanced Timestamp or the Checksum Offload Engine is enabled. Note: When the Advanced Timestamp or Checksum Offload Engine features are enabled, software should set the ATDS bit of the Ethernet MAC DMA Bus Mode (EMACDMABUSMOD) 1418 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller register, offset 0xC00, so that the DMA operates with extended descriptor size. When this control bit is reset to the default (0), the TDES4-TDES7 descriptor space is not valid and only Alternate Descriptors are available, with a default size of 16 bytes (4 words). Figure 20-4. Enhanced Receive Descriptor Structure 31 23 15 RDES0 OWN 7 0 Status [30:0] Reserved RDES1 CTRL [30:29] Byte Count Buffer2 [28:16] RDES2 RDES3 CTRL Reserved [15:14] Byte Count Buffer 1 [12:0] Buffer1 Address [31:0] Buffer2 Address [31:0]/Next Descriptor Address [31:0] RDES4 Extended Status [31:0] RDES5 Reserved RDES6 Receive Timestamp Low [31:0] RDES7 Receive Timestamp High [31:0] The following tables define the Enhanced Receive Descriptors. RDES0 contains the received frame status, the frame length, and the descriptor ownership information. RDES1 contains the buffer sizes and other bits that control the descriptor chain or ring. RDES2 and RDES3 contains the address pointers to the first and second data buffers in the descriptor. The availability of the extended status is indicated by Bit 0 of RDES0. RDES6 and RDES7 are available only when the Advanced Timestamp or IP Checksum Full Offload feature is enabled. Table 20-8. Enhanced Receive Descriptor 0 (RDES0) Bit 31 Description OWN: Own Bit When set, this bit indicates that the descriptor is owned by the DMA. When this bit is reset, it indicates that the descriptor is owned by the Host. The DMA clears this bit either when it completes the frame reception or when the buffers that are associated with this descriptor are full. 30 AFM: Destination Address Filter Fail When set, this bit indicates a frame failed in the DA filter in the MAC. June 18, 2014 1419 Texas Instruments-Production Data Ethernet Controller Table 20-8. Enhanced Receive Descriptor 0 (RDES0) (continued) Bit 29:16 Description FL: Frame Length These bits indicate the byte length of the received frame that was transferred to the system memory. This field is valid when the Last Descriptor (RDES0[8]) is set and either the Descriptor Error (RDES0[14]) or the Overflow Error bit (RDES0[11]) is clear. When the Last Descriptor bit is not set, this field indicates the accumulated number of bytes that have been transferred for the current frame. The inclusion of CRC length in the frame length depends on the settings of CRC configuration bits, ACS and CST in the EMACCFG register. 15 ES: Error Summary Indicates the logical OR of the following bits: ■ RDES0[14]: Descriptor Error ■ RDES0[11]: Overflow Error ■ RDES0[7]: IPC Checksum (Type 2) or Giant Frame ■ RDES0[6]: Late Collision ■ RDES0[4]: Watchdog Timeout ■ RDES0[3]: Receive Error ■ RDES0[1]: CRC Error ■ RDES[4:3]: IP Header or Payload Error This field is valid only when the Last Descriptor (RDES0[8]) is set. 14 DE: Descriptor Error When set, this bit indicates a frame truncation caused by a frame that does not fit within the current descriptor buffers, and that the DMA does not own the Next Descriptor. The frame is truncated. This field is valid only when the Last Descriptor (RDES0[8]) is set. 13 SAF: Source Address Filter Fail When set, this bit indicates that the SA field of frame failed the SA Filter in the MAC. 12 LE: Length Error When set, this bit indicates that the actual length of the frame received and the Length/Type field do not match. This bit is valid only when the Frame Type (RDES0[5]) bit is reset. Length error status is not valid when CRC error is present. 11 OE: Overflow Error When set, this bit indicates that the received frame is damaged because of buffer overflow in RX FIFO. Note: 10 This bit is set only when the DMA transfers a partial frame to the application. This happens only when the RX FIFO is operating in the threshold mode. In the store-and-forward mode, all partial frames are dropped completely in RX FIFO. VLAN: VLAN Tag When set, this bit indicates that the frame pointed to by this descriptor is a VLAN frame tagged by the MAC. The VLAN tagging depends on checking VLAN fields of the received frame configured in the Ethernet MAC VLAN Tag (EMACVLANTG) register, offset 0x01C 9 FS: First Descriptor When set, this bit indicates that this descriptor contains the first buffer of the frame. If the size of the first buffer is 0, the second buffer contains the beginning of the frame. If the size of the second buffer is also 0, the next Descriptor contains the beginning of the frame. 8 LS: Last Descriptor When set, this bit indicates that the buffers pointed to by this descriptor are the last buffers of the frame. 1420 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 20-8. Enhanced Receive Descriptor 0 (RDES0) (continued) Bit 7 Description Timestamp Available or Giant Frame When Advanced Timestamp feature is enabled, this bit indicates that a snapshot of the Timestamp is written in descriptor words 6 (RDES6) and 7 (RDES7). This is valid only when the Last Descriptor bit (RDES0[8]) is set. Otherwise, this bit, when set, indicates the Giant Frame Status. Giant frames are larger than 1,518-byte (or 1,522-byte for VLAN or 2,000-byte when Bit 27 of MAC Configuration register is set) normal frames and larger than 9,018-byte (9,022-byte for VLAN) frame when Jumbo Frame processing is enabled. 6 LC: Late Collision When set, this bit indicates that a late collision has occurred while receiving the frame in half-duplex mode. 5 FT: Frame Type When set, this bit indicates that the Receive Frame is an Ethernet-type frame (the LT field is greater than or equal to 1,536). When this bit is reset, it indicates that the received frame is an IEEE 802.3 frame. This bit is not valid for Runt frames less than 14 bytes. In addition when the IPC bit is set in the EMACCFG register, this bit conveys different information. See Table 20-9 on page 1421. 4 RWT: Receive Watchdog Timeout When set, this bit indicates that the Receive Watchdog Timer has expired while receiving the current frame and the current frame is truncated after the Watchdog Timeout. 3 RE: Receive Error When set, this bit indicates that an error occurred during frame reception. 2 DE: Dribble Bit Error When set, this bit indicates that the received frame has a non-integer multiple of bytes (odd nibbles). 1 CE: CRC Error When set, this bit indicates that a Cyclic Redundancy Check (CRC) Error occurred on the received frame. This field is valid only when the Last Descriptor bit (RDES0[8]) is set. 0 Extended Status Available/RX MAC Address When set, this bit indicates that the extended status is available in descriptor word 4 (RDES4). This is valid only when the Last Descriptor bit (RDES0[8]) is set. This bit is invalid when Bit 30 is set. Table 20-9 on page 1421 shows the frame information conveyed in bits 7, 5, and 0 of RDES0 when the Checksum Offload Engine is enabled and disabled through the IPC bit in the EMACCFG register. Table 20-9. RDES0 Checksum Offload bits Bit 5: Frame Type Bit 7: IPC Bit 0: Payload IPC bit value Checksum Checksum in EMACCFG Error Error register Frame Status 0 0 0 X IEEE 802.3 Type frame (Length field value is less than 1,536). This status definition is valid even when the Checksum Offload engine is disabled. 1 0 0 0 IPv4/IPv6 Type frame in which no checksum error is detected. 1 0 0 1 The frame is an IEEE 802.3 Type frame (Length field value is greater than or equal to 1,536). 1 0 1 1 IPv4/IPv6 Type frame with a payload checksum error detected 1 1 1 1 IPv4/IPv6 Type frame with both IP header and payload checksum errors detected 0 0 1 1 IPv4/IPv6 Type frame with no IP header checksum error and the payload check bypassed, due to an unsupported payload 0 1 1 1 A Type frame that is neither IPv4 or IPv6 (the Checksum Offload engine bypasses checksum completely.) 0 1 0 X Reserved June 18, 2014 1421 Texas Instruments-Production Data Ethernet Controller Table 20-10. Enhanced Receive Descriptor 1 (RDES1) Bit 31 Description Disable Interrupt on Completion When set, this bit prevents the setting of the Receive Interrupt (RI) bit in the EMACDMARIS register and prevents the receive interrupt from being asserted. 30:29 Reserved 28:16 RBS2: Receive Buffer 2 Size These bits indicate the second data buffer size. The buffer size must be a multiple of 4, even if the value of RDES3 (buffer 2 address pointer) is not aligned to the bus width. When the buffer size is not a multiple of 4, the resulting behavior is undefined. This field is not valid if RCH bit (RDES1[14]) is set. 15 RER: Receive End of Ring When set, this bit indicates that the descriptor list reached its final descriptor. The DMA returns to the base address of the list, creating a Descriptor Ring. 14 RCH: Second Address Chained When set, this bit indicates that the second address in the descriptor is the Next Descriptor address rather than the second buffer address. When this bit is set, RBS2 (RDES1[28:16]) is a "don’t care" value. RDES1[15] takes precedence over RDES1[14]. 13 12:0 Reserved RBS1: Receive Buffer 1 Size These bits indicate the first data buffer size in bytes. The buffer size must be a multiple of 4 even if the value of RDES2 (buffer 1 address pointer) is not aligned to the bus width. When the buffer size is not a multiple of 4, the resulting behavior is undefined. If this field is 0, the DMA ignores this buffer and uses Buffer 2 or the next descriptor depending on the value of RCH (Bit 14). Table 20-11. Enhanced Receive Descriptor 2 (RDES2) Bit 31:0 Description Buffer 1 Address Pointer These bits indicate the physical address of Buffer 1. The DMA uses the configured value for its address generation when the RDES2 value is used to store the start of frame. The DMA performs a write operation with the RDES2[1:0] bits as 0 during the transfer of the start of frame but the frame data is shifted as per the actual Buffer address pointer. The DMA ignores RDES2[1:0] if the address pointer is to a buffer where the middle or last part of the frame is stored. Note that buffers should be word-aligned. Table 20-12. Enhanced Receive Descriptor 3 (RDES3) Bit 31:0 Description Buffer 2 Address Pointer (Next Descriptor Address) These bits indicate the physical address of Buffer 2 when a descriptor ring structure is used. If the Second Address Chained (RDES1[14]) bit is set, this address contains the pointer to the physical memory where the Next Descriptor is present. If RDES1[14] is set, the buffer (Next Descriptor) address pointer must be bus word-aligned (RDES3[1:0] = 0) However, when RDES1[14] is reset, there are no limitations on the RDES3 value, except for the following condition: The DMA uses the configured value for its buffer address generation when the RDES3 value is used to store the start of frame. The DMA ignores RDES3 [1:0] if the address pointer is to a buffer where the middle or last part of the frame is stored. Table 20-13. Enhanced Received Descriptor 4 (RDES4) Bit 31:15 Description Reserved 1422 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 20-13. Enhanced Received Descriptor 4 (RDES4) (continued) Bit 14 Description Timestamp Dropped When set, this bit indicates that the timestamp was captured for this frame but got dropped in the RX FIFO because of overflow. 13 PTP Version When set, this bit indicates that the received PTP message uses the IEEE 1588 version 2 format. When reset, it uses the version 1 format. 12 PTP Frame Type When set, this bit indicates that the PTP message is sent directly over Ethernet. When this bit is clear and the message type is non-zero, it indicates that the PTP message is sent over UDP-IPv4 or UDP-IPv6. The information about IPv4 or IPv6 can be obtained from Bits 6 and 7. 11:8 MessageType These bits are encoded to give the type of the message received: 7 ■ 0x0= No PTP message received ■ 0x1= SYNC (all clock types) ■ 0x2= Follow_Up (all clock types) ■ 0x3= Delay_Req (all clock types) ■ 0x4= Delay_Resp (all clock types) ■ 0x5= Pdelay_Req (in peer-to-peer transparent clock) ■ 0x6= Pdelay_Resp (in peer-to-peer transparent clock) ■ 0x7= Pdelay_Resp_Follow_Up (in peer-to-peer transparent clock) ■ 0x8= Announce ■ 0x9= Management ■ 0xA= Signaling ■ 0xB to 0xE= Reserved ■ 0xF= PTP packet with Reserved message type IPv6 Packet Received When set, this bit indicates that the received packet is an IPv6 packet. This bit is updated only when the IPC bit of the EMACCFG register is set. 6 IPv4 Packet Received When set, this bit indicates that the received packet is an IPv4 packet. This bit is updated only when the IPC bit of the EMACCFG register is set. 5 IP Checksum Bypassed When set, this bit indicates that the checksum offload engine is bypassed. 4 IP Payload Error When set, this bit indicates that the 16-bit IP payload checksum (that is, the TCP, UDP, or ICMP checksum) that the core calculated does not match the corresponding checksum field in the received segment. It is also set when the TCP, UDP, or ICMP segment length does not match the payload length value in the IP Header field. This bit is valid when either Bit 7 or Bit 6 is set. 3 IP Header Error When set, this bit indicates that either the 16-bit IPv4 header checksum calculated by the core does not match the received checksum bytes, or the IP datagram version is not consistent with the Ethernet Type value. This bit is valid when either Bit 7 or Bit 6 is set. June 18, 2014 1423 Texas Instruments-Production Data Ethernet Controller Table 20-13. Enhanced Received Descriptor 4 (RDES4) (continued) Bit 2:0 Description IP Payload Type These bits indicate the type of payload encapsulated in the IP datagram processed by the Receive Checksum Offload Engine (COE). The COE sets this field to 0x0 if it does not process the IP datagram's payload due to an IP header error or fragmented IP packet. ■ 0x0= Unknown or did not process IP payload ■ 0x1= UDP ■ 0x2= TCP ■ 0x3= ICMP ■ 0x4 to 0x7= Reserved This bit is valid when either Bit 7 or Bit 6 is set. Table 20-14. Enhanced Receive Descriptor 6 (RDES6) Bit 31:0 Description RTSL: Receive Frame Timestamp Low This field is updated by the DMA with the least significant 32 bits of the timestamp captured for the corresponding receive frame. This field is updated by the DMA only for the last descriptor of the receive frame which is indicated by Last Descriptor status bit (RDES0[8]). Table 20-15. Enhanced Receive Descriptor 7 (RDES7) Bit 31:0 Description RTSH: Receive Frame Timestamp High This field is updated by DMA with the most significant 32 bits of the timestamp captured for the corresponding receive frame. This field is updated by DMA only for the last descriptor of the receive frame which is indicated by Last Descriptor status bit (RDES0[8]). 20.3.2.6 DMA Transmission Operation The following sections describe the modes of the transmit operation. TX DMA Default Operation The TX DMA engine in default mode, operates as follows: 1. The CPU configures the transmit descriptor (TDES0-TDES3) and sets the OWN bit (TDES0[31]) after setting up the corresponding data buffers with the Ethernet frame. 2. When the ST bit of the Ethernet MAC DMA Operation Mode (EMACDMAOPMODE) register, offset 0xC18, is set, the DMA enters the RUN state. 3. While in RUN state, the DMA polls the Transmit Descriptor list for frames requiring transmission. After polling starts, it continues in either sequential descriptor ring order or chained order. If the DMA detects a descriptor flagged as owned by the CPU (TDES0[31]=0), or if an error condition occurs, transmission is suspended and both the Transmit Buffer Unavailable (TU) bit and the Normal Interrupt Summary (NIS) bit are set in the Ethernet MAC DMA Interrupt Status (EMACDMARIS) register, offset 0xC14. The transmit engine the proceeds to Step 9. 1424 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 4. If the acquired descriptor is flagged as owned by the DMA (TDES0[31]=1), the DMA decodes the transmit data buffer address from the acquired descriptor. 5. If the acquired descriptor is flagged as owned by DMA (TDES0[31] = 1), the DMA decodes the Transmit Data Buffer address from the acquired descriptor. 6. The DMA fetches the transmit data from system memory and transfers the data to the TX/RX Controller for transmission. 7. If the Ethernet frame is stored over data buffers in multiple descriptors, the DMA closes the intermediate descriptor and fetches the next descriptor. Steps 3, 4, and 5 are repeated until the end of the Ethernet frame data is transferred to the TX/RX Controller. 8. When frame transmission is complete, if IEEE 1588 timestamping was enabled for the frame (as indicated in the transmit status) the timestamp value is written to the transmit descriptor (TDES6 and TDES7) that contains the end-of-frame buffer. The status information is then written to transmit descriptor TDES0. Because the OWN bit is cleared during this step, the CPU now owns this descriptor. If timestamping was not enabled for this frame, the DMA does not alter the contents of TDES6 and TDES7. 9. The Transmit Interrupt (TI) bit is set in the EMACDMARIS register after transmission completion of a frame that has Interrupt on Completion set in its last descriptor. The Interrupt on Completion bit resides in TDES0[30]. The DMA engine then returns to Step 3. 10. In the suspend state, the DMA tries to reacquire the descriptor (and thereby return to Step 3) when it receives a transmit poll demand in the Ethernet MAC Transmit Poll Demand (EMACTXPOLLD) register, offset 0xC04, and the Underflow Interrupt Status (UNF) bit is cleared in the EMACDMARIS register. If the CPU stopped the DMA by clearing the ST bit of the EMACDMAOPMODE register, the DMA enters the STOP state. Figure 20-5 on page 1426 shows the flow for the TX DMA default operation. June 18, 2014 1425 Texas Instruments-Production Data Ethernet Controller Figure 20-5. TX DMA Default Operation Using Descriptors Start Tx DMA Start A Stop Tx DMA (Re-)fetch next descriptor Poll demand Start = 0 A Error Condition? Ye s No Tx DMA suspended OWN bit set? No Yes Transfer data from buffer(s) Error Condition? Yes No No Frame xfer complete? Yes Close intermediate descriptor Wait for Tx status Timestamp present? Yes Write timestamp to TDES6 and TDES7 No Write status word to TDES0 No No Error Condition? Error Condition? Ye s Yes TX DMA OSF Mode Operation While in the RUN state, the transmit process can simultaneously acquire two frames without closing the Status descriptor of the first if the OSF bit of the EMACDMAOPMODE register is set. As the transmit process finishes transferring the first frame, it immediately polls the transmit descriptor list 1426 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller for the second frame. If the second frame is valid, the transmit process transfers this frame before writing the first frame's status information. In Operate on Second Frame (OSF) mode, the RUN state TX DMA operates in the following sequence: 1. The DMA operates as described in Steps 1 to 6 (see page 1424). 2. Without closing the previous frame's last descriptor, the DMA fetches the next descriptor. 3. If the DMA owns the acquired descriptor, the DMA decodes the transmit buffer address in this descriptor. If the DMA does not own the descriptor, the DMA goes into SUSPEND mode and skips to 7. 4. The DMA fetches the Transmit frame from system memory and transfers the frame until the end-of-frame data is reached. It closes the intermediate descriptors if this frame is split across multiple descriptors. 5. The DMA waits for the previous frame's transmission status and timestamp. When the status is available, the DMA writes the timestamp to TDES6 and TDES7, if such timestamp was captured (as indicated by a status bit). The DMA then writes the status, with a cleared OWN bit, to the corresponding TDES0, thus closing the descriptor. If timestamping was not enabled for the previous frame, the DMA does not alter the contents of TDES6 and TDES7. 6. If enabled, the Transmit interrupt (TI) bit is set in the EMACDMARIS register, the DMA fetches the next descriptor and then proceeds to 3 (when Status is normal). If the previous transmission status shows an underflow error, the DMA goes into SUSPEND mode 7. In SUSPEND mode, if a pending status and timestamp are received, the DMA writes the timestamp (if enabled for the current frame) to TDES6 and TDES7, then writes the status to the corresponding TDES0. It then sets relevant interrupts and returns to SUSPEND mode. 8. The DMA can exit SUSPEND mode and enter the RUN state only after receiving the Transmit Poll demand in the EMACTXPOLLD register. Note: The DMA fetches the next descriptor in advance before closing the current descriptor. Therefore, the descriptor chain should have more than two different descriptors for correct and proper operation. Figure 20-6 on page 1428 shows the flow for the TX DMA Operate-On-Second-Frame (OSF) operation. June 18, 2014 1427 Texas Instruments-Production Data Ethernet Controller Figure 20-6. TX DMA OSF Mode Operation Using Descriptors Start Tx DMA A Stop Tx DMA (Re-)fetch next descriptor A No pending status and Start = 0 Start Error Condition? Poll demand Ye s No Tx DMA suspended No OWN bit set? Yes Previous frame status available Transfer data from buffer(s) Error Condition? Timestamp present? Yes No Yes No Frame xfer complete? Write timestamp to TDES6 and TDES7 for previous frame No Ye s No Yes Wait for previous frame’s Tx status Close intermediate descriptor Error Condition? Yes Timestamp present? No Yes Write timestamp to TDES6 & TDES7 for previous frame No Write status word to prev. frame’s TDES0 Write status word to prev frame’s TDES0 No Second frame? Error Condition? No No Error Condition? Yes Error Condition? Yes Yes Transmit Frame Processing The TX DMA expects that the data buffers contain complete Ethernet frames, excluding preamble, pad bytes, and Frame Check Sequence (FCS) fields. The Destination Address (DA), Source Address (SA), and Type/Length fields must contain valid data. If the Transmit Descriptor indicates that the MAC must disable CRC or PAD insertion, the buffer must have complete Ethernet frames (excluding preamble), including the CRC bytes. Frames can be data-chained and can span several buffers. Frames must be delimited by the First Segment Descriptor and the Last Segment Descriptor, 1428 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller respectively. The First Descriptor bit is located at TDES0[28] and the Last Descriptor is located at TDES0[29]. As transmission starts, the First Descriptor must have TDES0[28] set. When this occurs, frame data transfers from the host memory buffer to the TX FIFO. Concurrently, if the current frame has the Last Segment Descriptor (TDES0[29]) clear, the transmit process attempts to acquire the next descriptor. The transmit process expects this descriptor to have TDES0[28] clear. If TDES0[29] is clear, it indicates an intermediary buffer. If TDES0[29] is set, it indicates the last buffer of the frame. After the last buffer of the frame has been transmitted, the DMA writes back the final status information to the Transmit Descriptor word of the descriptor that has the last segment bit set in Transmit Descriptor. At this time, if Interrupt on Completion (IC) bit is set, the TI bit in the EMACDMARIS register is set, the next descriptor is fetched and the process repeats. The actual frame transmission begins after the TX FIFO has reached either the transmit threshold as configured by the TTC bit field of the EMACDMAOPMODE register, or a full frame is contained in the TX FIFO. To wait until there is a full frame in the TX FIFO the TSF bit in the EMACDMAOPMODE register must be set. Descriptors are released (OWN bit in the TDES0[31] cleared) when the DMA finishes transferring the frame. Note: To ensure proper transmission of a frame and the next frame, the transmit descriptor that has the Last Descriptor bit (TDES0[29]) set, must specify a non-zero buffer size. Transmit Polling Suspended Transmit polling can be suspended by either of the following conditions: ■ The DMA detects a descriptor owned by the CPU (TDES0[31]=0). To resume, the driver must give descriptor ownership to the DMA and then issue a Poll Demand command. ■ A frame transmission is aborted when a transmit error because of underflow is detected. The appropriate Transmit Descriptor 0 (TDES0) bit is set. If the DMA goes into SUSPEND state because of the first condition, then both the Normal Interrupt Summary (NIS) bit and the Transmit Buffer Unavailable (TU) bit are set in the EMACDMARIS register. If the second condition occurs, the Abnormal Interrupt Summary (AIS) bit and the Transmit Underflow (UNF) bit of the EMACDMARIS register are set and the information is written to Transmit Descriptor 0, causing the suspension. In both cases, the position in the Transmit list is retained . The retained position is that of the descriptor following the last descriptor closed by the DMA. The driver must explicitly issue a Transmit Poll Demand command after rectifying the suspension case. 20.3.2.7 DMA Receive Operation The following section describes the receive operation process. Default Receive Operation The RX DMA engine's reception sequence is as follows: 1. The host sets up receive descriptors (RDES0-RDES3) and sets the OWN bit (RDES0[31]). 2. When the SR bit of the EMACDMAOPMODE register is set, the DMA enters the RUN state. While in the RUN state, the DMA polls the Receive Descriptor list, attempting to acquire free descriptors. If the fetched descriptor is not free (is owned by the CPU), the DMA enters the Suspend state and jumps to Step 9. June 18, 2014 1429 Texas Instruments-Production Data Ethernet Controller 3. The DMA decodes the receive data buffer address from the acquired descriptors. 4. Incoming frames are processed and placed in the acquired descriptor's data buffers. 5. When the buffer is full or the frame transfer is complete, the RX DMA engine fetches the next descriptor. 6. If the current frame transfer is complete, the DMA proceeds to Step 7. If the DMA does not own the next fetched descriptor and the frame transfer is not complete (EOF is not yet transferred), the DMA sets the Descriptor Error (DE) bit in RDES0 (unless flushing is disabled through the DFF bit in the EMACDMAOPMODE register). The DMA closes the current descriptor (clears the OWN bit) and marks it as intermediate by clearing the Last Segment (LS) bit in the RDES0 value. If flushing is not disabled, then the DMA would mark it as the last descriptor. In either case, the DMA proceeds to Step 8. If the DMA does own the next descriptor but the current frame transfer is not complete, the DMA closes the current descriptor as intermediate and reverts to Step 4. 7. If IEEE 1588 timestamping is enabled, the DMA writes the timestamp to the current descriptor's RDES6 and RDES7. It then takes the receive frame's status and writes the status word to the current descriptor's RDES0, with the OWN bit cleared and the Last Segment (LS) bit set. If the host stopped the RX DMA by clearing the SR bit of the EMACDMAOPMODE register, DMA goes to the STOP state, otherwise the RX DMA proceeds to Step 8. 8. The RX DMA engine checks the last descriptor's OWN bit. If the CPU owns the descriptor (OWN bit is 0), the RU bit of the EMACDMARIS register is set and the DMA RX engine enters the SUSPEND state. If the DMA owns the descriptor, the engine returns to Step 4 and awaits the next frame. 9. Before the RX DMA engine enters the SUSPEND state, partial frames are flushed from the RX FIFO. Flushing can be controlled through the DFF bit of the EMACDMAOPMODE register. 10. The RX DMA enters the STOP state if the CPU has cleared the SR bit of the EMACDMAOPMODE register. Otherwise, it exits the SUSPEND state when a Receive Poll Demand is given or the start of the next frame is available from the RX FIFO. The DMA engine proceeds to Step 2 and re-fetches the next descriptor. The DMA does not acknowledge accepting status from the TX/RX Controller until it has completed the timestamp write-back and is ready to perform status write-back to the descriptor. If software has enabled timestamping through the Ethernet MAC Timestamp Control (EMACTIMSTCTRL) register, offset 0x700, when a valid timestamp is not available for the frame (for example, because the receive FIFO was full before the timestamp could be written to it), the DMA writes all-ones to RDES6 and RDES7. Otherwise if timestamping is not enabled, RDES6 and RDES7 remain unchanged. Figure 20-7 on page 1431 shows the flow of a RX DMA Operation. 1430 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 20-7. RX DMA Operation Flow Start RxDMA Start = 0 A Poll demand/ new frame available A Stop RxDMA (Re-)Fetch next descriptor Error Condition? RxDMA suspended Yes No Yes Frame transfer complete? No Own bit set? Yes No Yes Start Flush disabled ? Frame data available ? No Yes Flush the remaining frame Write data to buffer(s) No Wait for frame data Error Condition? Yes No Fetch next descriptor Error Condition? Yes No Flush disabled ? No No Yes Set descriptor error Own bit set for next desc? Yes No Frame transfer complete? Yes Close RDES0 as intermediate descriptor Time stamp present? Yes Write time stamp to RDES6 & RDES7 No Close RDES0 as last descriptor No Error Condition? Yes Start = 0 Error Condition? No Yes Receive Descriptor Acquisition The Receive Engine always attempts to acquire an extra descriptor in anticipation of an incoming frame. Descriptor acquisition is attempted if any of the following conditions is satisfied: June 18, 2014 1431 Texas Instruments-Production Data Ethernet Controller ■ The SR bit of the EMACDMAOPMODE register has been set immediately after being placed in the RUN state. ■ The data buffer or current descriptor is full before the frame ends for the current transfer. ■ The controller has completed frame reception, but the current receive descriptor is not yet closed. ■ The receive process has been suspended because of a host-owned buffer (RDES0[31]=0) and a new frame is received. ■ A receive poll demand has been issued. Receive Frame Processing The MAC transfers the received frames to the system memory only when the frame passes the address filter and the frame size is greater than or equal to configurable threshold bytes set for the RX FIFO, or when the complete frame is written to the RX FIFO in store-and-forward mode. If the frame fails the address filtering, it is dropped in the MAC block unless the Receive All (RA) bit is set in the Ethernet MAC Frame Filter (EMACFRAMEFLTR), offset 0x004. If the RA bit is set, then the MAC passes all received frames. Frames that are shorter than 64 bytes, because of collision or premature termination, can be removed from the RX FIFO if the DFF bit is clear in the EMACDMAOPMODE register. After 64 bytes have been received, the TX/RX Controller requests the DMA block to begin transferring the frame data to the receive buffer pointed by the current descriptor. The DMA sets the First Descriptor (RDES0[9]) bit to delimit the frame after the DMA Interface becomes ready to receive a data transfer (if DMA is not fetching transmit data from the system memory). The descriptors are released when the OWN (RDES0[31]) bit is reset to 0, either as the data buffer fills up or as the last segment of the frame is transferred to the receive buffer. If the frame is contained in a single descriptor, both Last Descriptor (RDES0[8]) and First Descriptor (RDES0[9]) are set. The DMA fetches the next descriptor, sets the Last Descriptor (RDES0[8]) bit, and releases the RDES0 status bits in the previous frame descriptor. Then the DMA sets the RI bit of the EMACDMARIS register. The same process repeats unless the DMA encounters a descriptor flagged as being owned by the host. If this occurs, the receive process sets the RU bit of the EMACDMARIS and enters the SUSPEND state. The position in the receive list is retained. Receive Process Suspend If a new receive frame arrives while the receive process is in SUSPEND state, the DMA refetches the current descriptor in the system memory. If the descriptor is now owned by the DMA, the receive process re-enters the RUN state and starts frame reception. If the descriptor is still owned by the CPU, by default, the DMA discards the current frame at the top of the RX FIFO and increments the missed frame counter. If more than one frame is stored in the RX FIFO, the process repeats. The discarding or flushing of the frame at the top of the RX FIFO can be prevented by disabling flushing through the DFF bit of the EMACDMAOPMODE register. In such conditions, the receive process sets the Receive Buffer Unavailable (RU) status and returns to the SUSPEND state. 20.3.2.8 DMA Interrupts Interrupts can be generated as a result of various transfer events. The current status of interrupts can be read from the EMACDMARIS register and are enabled to trigger an interrupt through the programming of the Ethernet MAC DMA Interrupt Mask (EMACDMAIM) register. There are two groups of transfer event interrupts: Normal and Abnormal. The following lists the two groups: 1432 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Normal Interrupts: – Transmit Interrupt (TI, bit 0): Indicates that frame transmission is complete. – Transmit Buffer Unavailable (TU, bit 2): Indicates the CPU owns the next descriptor in the transmit list and the DMA cannot acquire it. – Receive Interrupt (RI, bit 6): Indicates the frame reception is complete. – Early Receive Interrupt (ERI, bit 14): Indicates the DMA has filled the first half of the data buffer of the packet ■ Abnormal Interrupts: – Transmit Process Stopped (TPS, bit 1): Indicates transmission is stopped., – Transmit Jabber Timeout (TJT, bit 3): Indicates the Transmit Jabber Timer expired. – Receive FIFO Overflow (OVF, bit 4): Indicates the receive buffer had an overflow during frame reception. – Transmit Underflow (UNF, bit 5): Indicates the transmit buffer had an underflow during frame transmission. – Receive Buffer Unavailable (RU, bit): Indicates the CPU owns the next descriptor in the receive list and the DMA cannot acquire it. – Receive Process Stopped (RPS, bit 8): Indicates the receive process entered the STOP state. – Receive Watchdog Timeout (RWT, bit 9): Indicates a frame length greater than 2 KB is received (10,240 when Jumbo Frame is enabled) – Early Transmit Interrupt (ETI, bit 10): Indicates a frame to be transmitted is fully transferred to the TX FIFO. – Fatal Bus Error (FBI, bit 13): Indicates a bus error occurred. Any of the interrupts in the Normal Interrupt group that are enabled in the EMACDMAIM register are ORed together to create the Normal Interrupt Summary (NIS) bit in the EMACDMARIS register. Any of the interrupts in the Abnormal Interrupt group that are enabled in the EMACDMAIM register are ORed together to create the Abnormal Interrupt Summary (AIS) bit in the EMACDMARIS register. Interrupts are cleared by writing a 1 to the corresponding bit position in the EMACDMARIS register. When all enabled interrupts within a group are cleared, the corresponding summary bit is cleared. Interrupts are not queued and if the interrupt event occurs again before the driver has responded to it, no additional interrupts are generated. An interrupt is only generated once for simultaneous, multiple events. The driver must read the EMACDMARIS register for the cause of the interrupt. The Ethernet MAC Receive Interrupt Watchdog Timer (EMACRXINTWDT) register, offset 0xC24 can be used to control the Receive Interrupt (RI) assertion. If the RDES1[31] bit (Receive Interrupt) bit has not been set in the receive descriptor and the EMACRXINTWDT register is programmed with a non-zero value, it gets activated as soon as the RX DMA completes a transfer of a received frame to system memory without asserting the receive interrupt. When this counter runs out as per the programmed value, the RI bit is set in the EMACDMARIS register and the interrupt is asserted June 18, 2014 1433 Texas Instruments-Production Data Ethernet Controller if the corresponding RI bit is enabled in the EMACDMAIM register. This counter gets disabled before it runs out if a frame is transferred to memory and the RI bit is set because it is enabled for that descriptor. 20.3.2.9 DMA Bus Error If an internal bus error occurs during a DMA transfer, the fatal bus error (FBI) interrupt is set in the EMACDMARIS register and the Access Error status (AE) bit field in the EMACDMARIS register indicates the type of error that caused the bus error. The DMA controller can resume operation only after soft resetting the Ethernet MAC and the re-initializing the DMA. 20.3.3 TX/RX Controller The TX/RX Controller consists of a FIFO memory which buffers and regulates the frames between the system memory and the MAC. It also controls the data transferred between clock domains. Both the transmit and receive data paths are 32-bits wide. The TX FIFO and RX FIFO are each 2 KB in depth. At reset, the TX/RX Controller is configured and ready to manage data flow to and from the DMA to the MAC. Note that the DMA and MAC must be initialized by the application out of reset. 20.3.3.1 Transmit (TX) Control Path The DMA controller is used for all Ethernet transmissions. The Ethernet frames are read from memory and transferred to the TX FIFO by the DMA. When the MAC is available, the frame is transferred from the FIFO. When the end-of-frame (EOF) is transferred, the MAC notifies the DMA the status of the transmission. The TX FIFO has a depth of 2 KB. The FIFO fill level has the capability of triggering the DMA to initiate a burst transfer. The DMA also transfers start-of-frame (SOF), end-of-frame (EOF), CRC and pad-insertion information to the TX/RX Controller so that this information can be passed to the MAC when it is ready for transmission from the TX FIFO. Data can be transmitted to the MAC in threshold mode or store-and-forward mode. If the TTC field is configured in the Ethernet MAC DMA Operation Mode (EMACDMAOPMODE) register at offset 0xC18 and the TSF bit in the same register is 0x0, then the TX Controller is operating in threshold mode. In this mode, the data is transferred to the MAC when the number of bytes in the FIFO crossed the value configured in the TTC bit field or when the end-of-frame is written before the threshold is crossed. In store-and forward mode, the TTC bit field is configured and the TSF bit is set. Data is transferred to the MAC only when one or more of the following conditions are true: ■ A complete frame is stored in the FIFO ■ The TX FIFO becomes almost full ■ The TX FIFO does not have space to accommodate the requested burst length With these conditions, the TX Controller continues store-and-forward mode even if the Ethernet frame length is bigger than the TX FIFO size. The TX FIFO can be flushed of all contents by setting the FTF bit in the EMACDMAOPMODE register. This bit is self-clearing and initializes the FIFO pointers to the default state. If the FTF bit is set during a frame transfer from the TX Controller to the MAC, then the TX Controller stops further transfer. Early termination of the transfer causes a underflow event and this status is communicated to the DMA. 1434 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Transmit Operation During a transmit, single-packet or double-packets can reside in the buffer. The following describes the details of each: ■ Single-packet transmit: During single packet transmission, the DMA controller fetches data from the CPU memory and forwards it to the TX FIFO and continues to receive data until the end-of-frame is transferred. The data is transmitted from the TX FIFO to the MAC by the TX/RX Controller when the threshold level is crossed or a full packet of data is received into the TX FIFO. When the TX/RX Controller receives acknowledgment from the MAC that it has received the EOF, it notifies the DMA so another transmit can begin. ■ Two-packet transmit: Because the DMA must update the descriptor status before releasing it to the CPU, there can be at most two frames inside a transmit FIFO. The second frame is fetched by the DMA and put into the TX FIFO only if the OSF bit is set in the EMACDMAOPMODE register at offset 0xC18. If this bit is not set, the next frame is fetched from memory only after the MAC has completely processed the frame and the DMA has released the descriptors. If the OSF bit is set, the DMA starts fetching the second frame immediately after completing the transfer of the first frame to the FIFO. It does not wait for the status to be updated. The TX/RX Controller receives the second frame into the FIFO while transmitting the first frame. As soon as the first frame has been transferred and the status is received from the MAC, the TX/RX Controller sends the acknowledgement to the DMA. If the DMA has already completed sending the second packet to the TX/RX Controller, it must wait for the status of the first packet before proceeding to the next frame. Collision and Retransmission If a collision occurs at the MAC application interface while the TX/RX Controller is transferring data to the MAC, the transmission is aborted and the MAC indicates a retry attempt by giving a collision status before the EOF is transferred to the TX/RX Controller from the DMA. This enables the TX/RX Controller to retry transmission of the frame data from the FIFO. After more than 96 bytes are transferred to the MAC, the FIFO controller clears space in the FIFO and makes it available to the DMA to transfer more data. Retransmission is not possible after this threshold is crossed or when the MAC indicates a late collision event. When a frame transmission is aborted because of underflow and a collision event follows, which initiates a retry, then the retry has higher priority than the abort. TX FIFO Flush Operation The TX FIFO can be flushed by setting the FTF bit in the EMACDMAOPMODE register. The flush operation is immediate and the TX/RX Controller clears the TX FIFO and the corresponding pointers to the initial state even if it is in the middle of transferring a frame to the MAC. The data which is already accepted by the MAC transmitter is not flushed. This data is scheduled for transmission and results in an underflow event because the TX FIFO did not complete the transfer or the rest of the frame. As in all underflow conditions, a runt frame is transmitted and observed on the line. The status of such a frame is marked with both underflow and frame flush events in the Transmit Descriptor 0 (TDES0) word. The TX/RX Controller also stops accepting any data from the DMA during the flush operation. It generates and transfers Transmit Status Words to the application for the frames that are flushed inside the FIFO, including partial frames. Frames that are completely flushed in the TX/RX Controller are identified by setting the Flush Status (FF) bit in the Transmit Descriptor 0 (TDES0) word. The TX/RX Controller completes the flush operation when the DMA accepts all of the status words for June 18, 2014 1435 Texas Instruments-Production Data Ethernet Controller the frames that were flushed and then clears the TX FIFO Flush control (FTF) bit in the EMACDMAOPMODE register. At this point, the TX/RX Controller starts accepting new frames from the DMA. Transmit Status Word At the end of the transfer of the Ethernet frame to the MAC and after the MAC completes the transmission of the frame, the TX/RX delivers a transmit status word (TDES0) to the application. If IEEE timestamping is enabled, the TX/RX Controller returns the specific frame's 64-bit timestamp, along with the transmit status word. The fields for the Transmit Descriptors are described in “Enhanced and Alternate Descriptors” on page 1413. 20.3.3.2 Receive (RX) Control Path TX/RX Controller receives frames from the MAC and pushes them into the RX FIFO. When the fill level of the RX FIFO crosses the programmed RX Threshold, the DMA is notified. Receive Operation During a receive operation the TX/RX Controller is a slave to the MAC. The steps of the receive operation are as follows: 1. The MAC receives a frame. This data, along with SOF, EOF and byte enable information is sent to the TX/RX Controller. The TX/RX Controller accepts the data and pushes it into the RX FIFO. After the EOF is transferred, the MAC drives the status word, which is also pushed in to the RX FIFO. 2. When timestamp is enabled by setting the TSEN bit in the Ethernet MAC Timestamp Control (EMACTIMSTCTRL) register, at offset 0x700, and the 64-bit timestamp is present with the receive status, it is appended to the frame and received by the MAC and pushed into the TX FIFO before the corresponding receive status word is written. Thus, two additional locations per frame are taken for storing timestamp in the RX FIFO. 3. Data can be sent to the TX/RX Controller in cut-through mode or store-and-forward mode. When the RTC bit field of the EMACDMAOPMODE register is set to 0x0 and cut-through mode is enabled (RSF=0), the TX/RX Controller indicates availability to transfer to the DMA when 64 bytes are in the RX FIFO or a full packet of data has been received into the RX FIFO. When the DMA initiates transfers to system memory, the TX/RX Controller continues to transfer data from the RX FIFO until a complete packet has been transferred. When EOF has occurred, the TX/RX Controller sends the status word to the DMA. Note: The timestamp transfer takes two clock cycles and the lower 32-bits of the timestamp are sent first when timestamping is enabled. When the RSF bit is set in the EMACDMAOPMODE register, RX FIFO store-and-forward mode is enabled and a frame is read by the DMA only after it is completely written into the RX FIFO. In this mode, only valid frames are read and forwarded to the application. In cut-through mode, some error frames are not dropped because the error status is received at the end of the frame and by that time the start of that frame has already been read out of the RX FIFO. The TX/RX Controller is capable of storing any number of frames in the RX FIFO as long as it is not full. 1436 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Error Handling If the RX FIFO is full before it receives the EOF data from the MAC, an overflow is declared, the entire frame (including the status word) is dropped and the Ethernet MAC Missed Frame and Buffer Overflow Counter (EMACMFBOC) register is incremented. These error actions occur even if the FEF bit is set in the EMACDMAPOPMODE register. If the start address of such a frame has already been transferred to the TX/RX Controller, the rest of the frame is dropped and a dummy EOF is written to the FIFO along with its status word. The descriptor status indicates a partial frame because of overflow. In such frames, the Frame Length (FL) field in the receive descriptor is invalid. If the RX FIFO is configured to operate in the store-and-forward mode and if the length of the received frame is more than the FIFO size, overflow occurs and all such frames are dropped. During error handling, the DMA flushes the error frame currently being read. The Receive control logic can filter error and undersized frames if enabled through configuring the FEF or FUF bit of the EMACDMAOPMODE register. Filtering must be set before the start address of the frame has been transferred to the TX/RX controller for it to take effect. Receive Word Status At the end of an Ethernet frame transfer to the system memory, the TX/RX Controller sends a receive status word, RDES0, to the application. Until the end of the frame transfer, the TX/RX Controller stores the status and frame length in an asynchronous status FIFO whose depth is determined by the size of the RX FIFO (2K) and the minimum size of the frame. If the frame size if 64, then the asynchronous FIFO depth is 2048/64 = 32 bytes in length. Note that when the status of a partial frame (because of overflow) is sent to the application, the Frame Length field of RDES0 is not valid and is set to zero. Note: 20.3.3.3 When the timestamp feature is enabled, the receive status field is greater than 32-bits. An extended status bit-field [63:32] provides information about the received Ethernet payload when it is carrying PTP packets or TCP/UDP/ICMP over IP packets. Since the data bus is 32 bits, the status is transferred over two clock cycles. MAC Flow Control Flow control mechanisms can be enabled for both the TX and RX FIFO datapath, depending on the configurations in the Ethernet MAC Flow Control (EMACFLOWCTL) register at offset 0x018 and the DUPM bit configuration in the Ethernet MAC Configuration (EMACCFG) register at offset 0x000. Table 20-16. TX MAC Flow Control TFE bit in EMACFLOWCTL DUPM bit in EMACCFG Description 0 X The MAC transmitter does not perform the flow control or backpressure operation. 1 0 The MAC transmitter performs backpressure when the FCBBPA bit in the Ethernet MAC Flow Control (EMACFLOWCTL) register is set. 1 1 The MAC transmitter sends a pause frame when the FCBBPA bit in the Ethernet MAC Flow Control (EMACFLOWCTL) register is set. Table 20-17. RX MAC Flow Control TFE bit in EMACFLOWCTL DUPM bit in EMACCFG Description 0 X The MAC receiver does not detect the received Pause frames. 1 0 The MAC receiver does not detect the received Pause frames but recognizes such frames as Control frames. June 18, 2014 1437 Texas Instruments-Production Data Ethernet Controller Table 20-17. RX MAC Flow Control (continued) 20.3.4 TFE bit in EMACFLOWCTL DUPM bit in EMACCFG Description 1 1 The MAC receiver detects or processes the Pause frames and responds to such frames by stopping the MAC transmitter. MAC Operation The MAC module enables the CPU to transmit and receive data over Ethernet in compliance with the IEEE 802.3-2008 standard. The MAC supports the interface to the PHY and is comprised of a receive and transmit module whose features are described in the following sections. 20.3.4.1 MAC Transmit Module MAC transmission is initiated when the TX/RX Controller transmits data with the start of frame (SOF) signal asserted. When the SOF signal is detected, the MAC accepts the data and begins transmitting to the PHY. The time required to transmit the frame data after the application initiates transmission varies, depending on delay factors like inter-frame gap (IFG) delay, time to transmit preamble or start of frame data (SFD), and any back-off delays for half-duplex mode. Until then, the MAC does not accept data received from the TX/RX Controller. After the end-of-frame (EOF) is transferred to the MAC, the MAC completes the normal transmission and gives the status of transmission to the TX/RX Controller. If a normal collision (in half-duplex mode) occurs during transmission, the MAC conveys the transmit status to the TX/RX Controller. It then accepts and drops all further data until the next SOF is received. The TX/RX Controller should retransmit the same frame from SOF on observing a retry request (in the transmit status word) from the MAC. The MAC issues an underflow status if the TX/RX Controller is not able to provide the data continuously during the transmission. During the normal transfer of a frame from the TX/RX Controller, if the MAC receives an SOF without getting an EOF for the previous frame, it ignores the SOF and considers the new frame as a continuation of the previous frame. If the number of bytes received from memory is less than 60 bytes, zeros are automatically appended to the transmitting frame to make the data length exactly 46 bytes to meet the minimum data field requirement of IEEE802.3. The transmit engine controls the operation of Ethernet frame transmission. Some of the functions of the transmit module include: ■ Output of (32-bit) Transmit Status (TDES0) to the application at the end of normal transmission or collision ■ Generating preamble and Start of Frame Data (SFD) ■ Generating jam pattern in half-duplex mode ■ Supporting Jabber time-out ■ Supporting flow control ■ Generating timestamp information for transmission ■ Scheduling frame transmission to satisfy inter-frame gap (IFG) and back-off delays ■ Generating CRC and FCS field for Ethernet Frame ■ Generating pause frames as necessary in full duplex mode 1438 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller When a new frame transmission is requested, the MAC transmit module sends out a preamble and SFD, followed by the data in the TX FIFO. The preamble is defined as 7 bytes of 0xAA and the SFD is defined as 1 byte of 0xAB pattern. The collision window is defined as 1 slot time (512-bit times). If a collision occurs any time from the beginning of the frame to the end of the CRC field, the MAC transmit module sends a 32-bit jam pattern of 0x5555.5555 to inform all other stations that a collision has occurred. If the collision is seen during the preamble transmission phase, the MAC transmit module completes the transmission of the preamble and SFD, and then sends the jam pattern. If the collision occurs after the collision window and before the end of the FCS field, the MAC transmit module sends a 32-bit jam pattern and sets the late collision bit in the transmit frame status. The jam pattern generation is applicable only to half-duplex mode. A jabber timer is enabled by default at reset in the MAC module. If the JD bit in the EMACCFG register at offset 0x000 is clear and the MAC module has transferred more than 2K bytes, the jabber timer causes the MAC module to stop transmission of Ethernet frames. The timeout is changed to 10 KB when the Jumbo Frame Enable (JFEN) bit is enabled in the EMACCFG register. The MAC transmit module uses a deferral mechanism for flow control (back pressure) in half-duplex mode. When the application requests to stop receiving frames, the transmit module sends a jam pattern of 32 bytes whenever it senses the reception of a frame, provided the transmit flow control is enabled. This results in a collision and the remote station backs off. If the application requests a frame to be transmitted, the frame is scheduled and transmitted even when backpressure is activated. If the backpressure is activated for a long time (more than 16 consecutive collision events occur) then the remote stations abort their transmissions because of excessive collisions. If IEEE 1588 timestamping is enabled for the transmit frame, the MAC transmit module takes a snapshot of the system time when the start-of-frame data is output on the bus. 20.3.4.2 MAC Transmit Module CRC Generator The Transmit CRC Generator is used to generate the 32-bit CRC for the FCS field of the Ethernet frame. The encoding is defined by the following generating polynomial: G(x) = x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x1. The calculated CRC is valid on the next clock after the data is received. 20.3.4.3 MAC Receive Module A receive operation is initiated when the MAC detects start-of-frame data (SFD). The MAC strips the preamble and SFD before proceeding to process the frame. The header fields are checked for the filtering and the FCS field is used to verify the CRC for the frame. The received frame is stored in a buffer until the address filtering is performed. The frame is dropped in the MAC if it fails the address filter. Some of the functions of the MAC receive module are as follows: ■ Stripping the preamble, SFD and carrier extension of the Ethernet frame ■ Providing IEEE 1588 timestamping whenever an SFD is detected ■ Converting receive nibble data into bytes in MII mode ■ Decoding Length/Type field of the Ethernet frame ■ Auto-CRC/pad stripping if enabled in the EMACCFG register June 18, 2014 1439 Texas Instruments-Production Data Ethernet Controller ■ Frame data and status buffering for received frames ■ Data path conversion of 8-bit data to 32-bit data ■ Frame filtering ■ Attaching calculated IP checksum input to frame ■ Detecting receiving pause frames and pausing the frame transmission for the delay specified withing the received pause frame ■ Receive IP Checksum Verification ■ Performing destination and source address checking functions on all received frames and reporting the address filtering status to the receive frame controller module. 20.3.4.4 MAC Receive Module CRC Generator The receive CRC Generator is used to generate the 32-bit CRC for the FCS field of the Ethernet frame. The encoding is defined by the following generating polynomial: G(x) = x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1 The calculated CRC is valid on the next clock after the data is received. 20.3.4.5 MAC Receive Frame Controller If the RA bit is set in the Ethernet MAC Frame Filter (EMACFRAMEFLTR) register, offset 0x004, the MAC Receive Frame Controller initiates the data transfer to the RX FIFO as soon as four bytes of Ethernet data are received. At the end of the data transfer, the received frame status that includes the frame filter bits (SA or DA filter fail) and status are also sent. These bits indicate to the application whether the received frame has passed the filter controls. This module does not drop any frame on its own in this mode. If the RA bit is clear, the MAC Receive Frame Controller performs frame filtering based on the destination/source address (the application still needs to perform another level of filtering if it decides not to receive any bad frames like runt, CRC error frames, etc.) After receiving the destination or source address bytes, the MAC Receive Frame Controller checks the filter-fail sign for an address match. On detecting a filter-fail, the frame is dropped and not transferred to the application. Note: 20.3.5 When the PMT module is configured for power-down mode, all received frames are dropped and not forwarded to the application. IEEE 1588 and Advanced Timestamp Function The MAC module supports the IEEE 1588-2002 Timestamp Precision Time Protocol (PTP) and the IEEE 1588-2008 Advanced Timestamp features. PTP enables precise synchronization of clocks in measurement and control systems implemented with technologies such as network communication, local computing, and distributed objects. The PTP applies to systems communicating by a local area network supporting multicast messaging. This protocol enables heterogeneous systems that include clocks of varying inherent precision, resolution, and stability to synchronize. The protocol supports system-wide synchronization accuracy in the sub-microsecond range with minimal network and local clock computing resources. The PTP is transported over UDP/IP. The system or network is classified into master and slave nodes for distributing the timing and clock information. Figure 20-8 on page 1441 shows the process that PTP uses for synchronizing a slave node to a master node by exchanging PTP messages. 1440 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 20-8. Networked Time Synchronization Master Clock Time Slave Clock Time t1 Sync message t2m Data at Slave Clock t2 t2 Follow_Up message containing value of t1 t1, t2 t3m t3 t1, t2, t3 Delay_Req message t4 Delay Resp message containing value of t4 t1, t2, t3, t4 time As shown in Figure 20-8 on page 1441, the PTP uses the following process: 1. The master broadcasts the PTP Sync messages to all its nodes. The Sync message contains the master's reference time information. The time at which this message leaves the master's system is t1. This time is captured at the MII interface. 2. The slave receives the Sync message and also captures the exact time, t2, using its timing reference. 3. The master sends a Follow_Up message to the slave, which contains t1 information for later use. 4. The slave sends a Delay_Req message to the master, noting the exact time, t3, at which this frame leaves the MAC. 5. The master receives the message, capturing the exact time, t4, at which it enters its system. 6. The master sends the t4 information to the slave in the Delay_Resp message. 7. The slave uses the four values of t1, t2, t3, and t4 to synchronize its local timing reference to the master's timing reference. Most of the PTP implementation is done in the software above the UDP layer. However, the hardware support is required to capture the exact time when specific PTP packets enter or leave the Ethernet June 18, 2014 1441 Texas Instruments-Production Data Ethernet Controller MAC. This timing information is captured and returned to the software for the proper implementation of PTP with high accuracy. 20.3.5.1 System Time Module The System Time module maintains a 64-bit time and is updated using the MOSC clock source as the PTP clock reference. This time is the source for taking snapshots (timestamps) of the Ethernet frames being transmitted or received. Two methods of updating the system time counter are implemented. The counter can be initialized or corrected using the coarse correction method. In this method, the initial value or the offset value is written to the MAC System Time - Seconds Update (EMACTIMSECU) register along with the MAC System Time - Nanoseconds Update (EMACTIMNANOU) register. For initialization the system time counter is written with the value in these registers, while for system time correction, the offset value is added to or subtracted from the system time. In the fine correction method, the slave clock's frequency drift with respect to the master clock is corrected over a period of time instead of in one clock, as in coarse correction. This helps maintain linear time and does not introduce drastic changes (or a large jitter) in the reference time between PTP Sync message intervals. In this method, an accumulator sums up the contents of the EMACTIMADD register, as shown in Figure 20-9 on page 1443. The arithmetic carry that the accumulator generates is used as a pulse to increment the system time counter. The accumulator and the addend are 32-bit registers. Here, the accumulator acts as a high precision frequency multiplier or divider. 1442 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 20-9. System Time Update Using Fine Correction Method EMACTIMADD EMACTIMSTCTRL. ADDREGUP + Accumulator Register Constant Value + Increment the Sub-Seconds Register EMACTIMNANO Increment the Seconds Register EMACTIMSEC Note: The MOSC clock that feeds the PTP reference clock to the System Time Module must be 25 MHz because it is also clocks the integrated PHY module. Initially, the Ethernet's slave clock (from the MOSC) is adjusted with a compensation value (as described in the previous paragraph) which is written to the Timestamp Addend Register (TSAR) field in the EMACTIMADD register. This value is calculated as: FreqCompensationValue0= TSAR = 232/ FreqDivisionRatio. The System Time Module requires a 20-MHz PTP reference clock frequency to achieve 50-ns accuracy in the fine correction method. An addend must be written to the Ethernet MAC Time Stamp Addend (EMACTIMADD) register, offset 0x718 to achieve timing synchronization. If the MOSC clock source is 25 MHz, the frequency division ratio (FreqDivisionRatio) of the two is calculated as 25 MHz / 20 MHz = 1.25. Hence, the default addend value to be set in the register is 232 / 1.25 or 0xCCCC.CCD0. If the reference clock drifts lower, to 24 MHz for example, the ratio is 24 / 20, or 1.2 and the value to set in the addend register is 232 / 1.20, or 0xDFF1.65D2. The software must calculate the drift in frequency based on the Sync messages and update the EMACTIMADD register, at offset 0x718, accordingly. If the master to slave delay is initially assumed to be the same for consecutive Sync messages, then the following steps can be used to calculate a new TSAR value. The following algorithm calculates the precise mater to slave delay value to allow for re-synchronization with the master using the new value: June 18, 2014 1443 Texas Instruments-Production Data Ethernet Controller 1. At time MasterSyncTimen the master sends the slave clock a Sync message. The slave receives this message when its local clock is SlaveClockTimen and computes MasterClockTimen as: MasterClockTimen = MasterSyncTimen + MasterToSlaveDelayn 2. The master clock count, MasterClockCountn, for the current Sync cycle is given by: MasterClockCountn = MasterClockTimen - MasterClockTimen-1 This assumes that the MasterToSlaveDelay is the same for Sync cycles n and n-1. 3. The slave clock count for current Sync cycle, SlaveClockCountn is given by: SlaveClockCountn = SlaveClockTimen – SlaveClockTimen – 1 4. The difference between the master and slave clock counts for the current Sync cycle, ClockDiffCountn, is given by: ClockDiffCountn = MasterClockCountn – SlaveClockCountn 5. The frequency-scaling factor for the slave clock, FreqScaleFactorn is given by: FreqScaleFactorn = (MasterClockCountn + ClockDiffCountn) / SlaveClockCountn 6. The frequency compensation value, FreqCompensationValue, to be written in the TSAR field of the EMACTIMADD register is: FreqCompensationValuen = FreqScaleFactorn * FreqCompensationValuen – 1 In theory, this algorithm achieves lock in one Sync cycle; however, it may take several cycles, because of changing network propagation delays and operating conditions. This algorithm is self-correcting: if for any reason the slave clock is initially set to a value from the master that is incorrect, the algorithm corrects it at the cost of more Sync cycles. 20.3.5.2 Transmit Timestamping The MAC captures a timestamp when the Start Frame Delimiter (SFD) of a frame is sent. The transmit frames are marked to indicate whether a timestamp should be captured for that frame and written to the extended transmit descriptors that support timestamping. The MAC returns the timestamp automatically to the corresponding transmit descriptor, thus connecting the timestamp with the specific PTP frame. The 64-bit timestamp information is written to the TDES6 and TDES7 fields. 20.3.5.3 Receive Timestamping The MAC captures the timestamp of all received frames. The MAC does not process the received frames to identify the PTP frames in default timestamping mode (when Advanced Timestamp is disabled). The MAC gives the timestamp and the corresponding status to the TX/RX Controller along with the EOF data. The TX/RX Controller validates and indicates the availability of the timestamp so that the DMA can return the timestamp to the corresponding receive descriptor. The 64-bit timestamp information is written to the RDES6 and RDES7 fields. The timestamp is written only to the receive descriptor for which the Last Descriptor status field has been set to 1 (the EOF marker). When the timestamp is not available (for example, because of an RX FIFO overflow), an all '1s' pattern is written to the descriptors (RDES6 and RDES7), indicating that the timestamp is not correct. If timestamping is disabled, the DMA does not alter RDES6 or RDES7. RDES0[7] indicates whether the timestamp is updated in RDES6 and RDES7. 1444 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 20.3.5.4 Timestamp Error Margin According to the IEEE 1588 specifications, a timestamp must be captured at the SFD of the transmitted and received frames at the MAC interface. Because the reference timing source, MOSC, is taken as different from MAC reference clocks, a small error margin is introduced, because of the transfer of information across asynchronous clock domains. In the transmit path, the captured and reported timestamp has a maximum error margin of 2 PTP (MOSC) clocks. It means that the captured timestamp has the reference timing source (MOSC) value that is given within 2 clocks after the SFD has been transmitted to the PHY. Similarly, in the receive path, the error margin is 3 MAC reference clocks, plus up to 2 PTP clocks. The error margin of the three MAC reference clocks can be ignored by assuming that this constant delay is present in the system (or link) before the SFD data reaches the interface of MAC. 20.3.5.5 Note: The reference clock to the integrated PHY must be 25 MHz. Note: When IEEE 1588 timestamping is enabled with internal timestamp, use a PTP clock frequency that is greater than 5 MHz. This is because the SSINC field in the EMACSUBSECINC register limits the PTP frequency that can be used to ~4 MHz. IEEE 1588-2008 Advanced Timestamps In addition to the basic timestamp features mentioned in IEEE 1588-2002 Timestamps, the Ethernet Controller supports the following advanced timestamp features defined in the IEEE 1588-2008 standard: ■ Supports the IEEE 1588-2008 (version 2) timestamp format. ■ Provides an option to take snapshot of all frames or only PTP type frames. ■ Provides an option to take snapshot of only event messages. ■ Provides an option to take the snapshot based on the clock type: ordinary, boundary, end-to-end, and peer-to-peer. ■ Provides an option to select the node to be a master or slave clock. ■ Identifies the PTP message type, version, and PTP payload in frames sent directly over Ethernet and sends the status. ■ Provides an option to measure sub-second time in digital or binary format. Peer-to-Peer Transparent Clock Message Support The IEEE 1588-2008 version supports Peer-to-Peer PTP (Pdelay) message in addition to SYNC, Delay Request, Follow-up, and Delay Response messages. Figure 20-10 on page 1446 shows the method to calculate the propagation delay in clocks supporting peer-to-peer path correction. June 18, 2014 1445 Texas Instruments-Production Data Ethernet Controller Figure 20-10. Propagation Delay Calculation in Clocks Supporting Peer-to-Peer Path Correction P2P TC A Delay Requester Time P2P TC B Delay Responder Time Timestamps known by Delay Requester t1 t1 Pdelay_Req tAB t2 t3 tBA t4 Pdelay_Resp Pdelay_Resp_Follow_Up: t2, t3 t1 ,t4 t1, t2, t3, t4 As shown in Figure 20-10 on page 1446, the propagation delay is calculated in the following way: 1. Port-1 issues a Pdelay_Req message and generates a timestamp, t1, for the Pdelay_Req message. 2. Port-2 receives the Pdelay_Req message and generates a timestamp, t2, for this message. 3. Port-2 returns a Pdelay_Resp message and generates a timestamp, t3, for this message. To minimize errors because of any frequency offset between the two ports, Port-2 returns the Pdelay_Resp message as quickly as possible after the receipt of the Pdelay_Req message. The Port-2 returns any one of the following: ■ The difference between the timestamps t2 and t3 in the Pdelay_Resp message. ■ The difference between the timestamps t2 and t3 in the Pdelay_Resp_Follow_Up message. ■ The timestamps t2 and t3 in the Pdelay_Resp and Pdelay_Resp_Follow_Up messages respectively. 4. Port-1 generates a timestamp, t4, on receiving the Pdelay_Resp message. 5. Port-1 uses all four timestamps to compute the mean link delay. Advanced Timestamp Supported Clock Types The Advance Timestamp Module supports an ordinary clock as defined by the IEEE 1588-2008 standard. The characteristics of this clock is as follows: 1446 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Sending and receiving of PTP messages. The timestamp snapshot can be controlled through the Ethernet MAC Timestamp Control (EMACTIMSTCTRL) register, offset 0x700. Timestamp snapshots can be for Sync messages. ■ Maintaining the data sets such as timestamp values. For an ordinary clock, snapshots can be taken of either version 1 or version 2 PTP types but not both. Selecting between the two is controlled by the PTPVER2 bit of the EMACTIMSTCTRL register. PTP Processing and Control There are fields in an Ethernet Payload that the Ethernet Controller can use to detect the PTP packet type and control the snapshot to be taken. These fields are different depending on whether the PTP frames are: ■ PTP frames over IPv4 ■ PTP frames over IPv6 ■ PTP frames over Ethernet The PTPIPV4, PTPIPV6 or PTPETH bits can be set depending on which PTP processing is required. Reference Timing Source The MAC supports the following reference timing source features defined in the IEEE 1588-2008 standard: ■ 80-bit timestamp ■ Fixed Pulse-Per-Second PPS0 Output ■ Flexible Pulse-Per-Second PPS0 Output 80-Bit Timestamp The MAC supports an 80-bit timestamp with a lengthened seconds integer portion which is 48-bits wide. The Ethernet MAC System Time - Seconds (EMACTIMSEC) register at offset 0x708 and the Ethernet MAC System Time-Higher Word Seconds (EMACHWORDSEC) register at offset 0x724 comprise the seconds count. The 32-bit Ethernet MAC System Time - Nanoseconds (EMACTIMNANO) register contains the fractional portion of the timestamp units of nanoseconds. The nanoseconds register supports the following two modes: ■ Digital rollover mode: In digital rollover mode, the maximum value in the nanoseconds field is 0x3B9A_C9FF, that is, (10e9-1) nanoseconds. ■ Binary rollover mode: In binary rollover mode, the nanoseconds field rolls over and increments the seconds field after value 0x7FFF_FFFF. Accuracy is ~0.466 ns per bit. Digital or binary rollover mode can be selected by programming the DGTLBIN bit of the EMACTIMSTCTRL register. Note that the timestamp maintained in the MAC is still 64-bits wide, but that the overflow to the upper 16-bits seconds register happens once in 130 years. June 18, 2014 1447 Texas Instruments-Production Data Ethernet Controller Fixed Pulse-Per-Second Output The Ethernet MAC module supports a pulse-per-second output feature such that the signal, EN0PPS, can indicate one second intervals. The frequency of the EN0PPS output can be changed by setting the PPSCTRL bit field of the Ethernet MAC PPS Control (EMACPPSCTRL) register, offset 0x72C. Flexible Pulse-Per-Second Output The Ethernet MAC also provides the ability to control the following features of the EN0PPS output: ■ Start or stop time ■ The start point of a single pulse and the start and stop points of the pulse train in terms of a 64-bit system time. The EMACTIMESEC and EMACTIMNANO registers are used to program the start and stop time. ■ The stop time can be programmed in advance of starting. ■ The signal width. The rising edge and the corresponding falling edge of the EN0PPS output can be programmed in terms of number of units of sub-second increment value programmed in the Ethernet MAC Sub-Second Increment (EMACSUBSECINC) register, offset 0x704. ■ The signal interval. The time between the rising edges of EN0PPS signal, in terms of number of units of sub-second increment value can be programmed in the Ethernet MAC PPS0 Interval (EMACPPS0INTVL) register, offset 0x760 . You can program the interval between pulses from 1 to 232-1 units of sub-second increment value. ■ Cancellation of the programmed EN0PPS start or stop request. ■ Error indication if the start or stop time being programmed has already passed. The start time can be programmed in the EMACTARGSEC and EMACTARGNANO registers. The TRGTBUSY bit in the EMACTARGNANO register indicates when the value is synchronized to the PTP clock domain. When this bit is clear, a new start time can be programmed, even before the earlier start time has elapsed. The start or stop time should be programmed with advanced system time to ensure proper EN0PPS signal output. If the application programs a start or stop time that has already elapsed, then the MAC sets an error status bit indicating the programming error. If enabled, the MAC also sets the Target Time Reached interrupt event. The application can cancel the start or stop request only if the corresponding start or stop time has not elapsed. If the time has elapsed, the cancel command has no effect. For a flexible EN0PPS output, the EMACPPS0INTVL and EMACPPS0WIDTH registers can be configured. The PPS0WIDTH and PPS0INT fields are programmed in terms of granularity of system time, that is, number of the units of sub-second increment value. For example, to have a EN0PPS pulse width of 80 ns and interval of 120ns, with the PTP reference clock of 25MHz, you should program the width and interval to values 1 and 2, respectively. Note that the PPS0WIDTH and PPS0INT value must be programmed as one less than the required interval. Before giving the command to trigger a pulse or pulse train on the EN0PPS output, the interval and width of the PPS signal output should be programmed or updated. Advanced Timestamp Transmit Path Functions The only aspect of the transmit path that changes with advanced timestamp is the descriptor, which extends to 32-bytes long. 1448 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller When you enable the advanced timestamp feature, the structure of the descriptor changes. The advanced timestamp feature is supported only through the enhanced descriptors format. The descriptor is 32-bytes long (eight words) and the snapshot of the timestamp is written in descriptor TDES6 and TDES7. Advanced Timestamp Receive Path Functions When the advanced timestamp feature is enabled, the MAC processes the received frames to identify valid PTP frames. The snapshot of the time sent to the application can be configured to: ■ Enable snapshot for all frames ■ Enable snapshot for IEEE 1588 version 2 or version 1 timestamp ■ Enable snapshot for PTP frames transmitted directly over Ethernet or UDP-IP-Ethernet ■ Enable timestamp snapshot for the received frame for IPv4 or IPv6 ■ Enable timestamp snapshot only for EVENT messages (SYNC, DELAY_REQ, PDELAY_REQ, or PDELAY_RESP) ■ Enable the node to be a master or slave and select the snapshot type. This controls the type of messages for which snapshots are taken The MAC provides the timestamp, along with EOF to the TX/RX Controller. The DMA returns the timestamp inside the corresponding receive descriptor. 20.3.6 Frame Filtering The following types of filtering are available for receive frames: ■ Source Address (SA) or Destination Address (DA) filtering ■ VLAN Filtering The frame filtering supports a sequence where the packet is not forwarded to VLAN filtering if it does not pass the SA or DA filtering first. 20.3.6.1 VLAN Filtering The Ethernet MAC provides VLAN Tag Perfect Filtering and VLAN Tag Hash Filtering. In VLAN tag perfect filtering, the MAC compares the VLAN tag of the received frame and provides the VLAN frame status to the application. Based on the programmed mode of the ETV bit in the EMACVLANTG register, the MAC compares the lower 12 bits or all 16 bits of the received VLAN tag to determine the perfect match. If VLAN tag perfect filtering is enabled, the MAC forwards the VLAN-tagged frames along with VLAN tag match status and drops the VLAN frames that do not match. Inverse matching for VLAN frames can also be enabled by setting the VTIM bit of the Ethernet MAC VLAN Tag (EMACVLANTG) register, offset 0x01C. In addition, matching of S-VLAN tagged frames along with the default C-VLAN tagged frames can be enabled by setting the ESVL bit of the EMACVLANTG register. The VLAN frame status bit (Bit 10 of RDES0) indicates the VLAN tag match status for the matched frames. Note: The Source or Destination Address filter has precedence over the VLAN tag filters. A frame which fails the Source or Destination Address filter is dropped irrespective of the VLAN tag filter results. June 18, 2014 1449 Texas Instruments-Production Data Ethernet Controller The MAC provides VLAN tag hash filtering with a 16-bit Hash table. The MAC performs the VLAN hash matching based on the VTHM bit of the EMACVLANTG register. If the VTHM bit is set, the most significant four bits of VLAN tag's CRC-32 are used to index the content of the Ethernet MAC VLAN Hash Table (EMACVLANHASH) register, offset 0x588. A value of 1 in the EMACVLANHASH register, corresponding to the index, indicates that the VLAN tag of the frame matched and the packet should be forwarded. A value of 0 indicates that VLAN-tagged frame should be dropped. The MAC also supports the inverse matching of the VLAN frames. In the inverse matching mode, when the VLAN tag of a frame matches the perfect or hash filter, the packet should be dropped. If the VLAN perfect and VLAN hash match are enabled, a frame is considered as matched if either the VLAN hash or the VLAN perfect filter matches. When inverse match is set, a packet is forwarded only when both perfect and hash filters indicate mismatch. Table 20-18 on page 1450 shows the different possibilities for VLAN matching and the final VLAN match status. When the RA bit of the EMACFRAMEFLTR register is set, all frames are received and the VLAN match status is indicated in Bit 10 of Receive Descriptor word 0 (RDES0). When the RA bit is not set and the VTFE bit in the EMACFRAMEFLTR register is set, the frame is dropped if the final VLAN match status is fail. In Table 20-18 on page 1450, value X means that this column can have any value. When the VL field is programmed to 0x0 in EMACVLANTG register, all VLAN-tagged frames are considered as perfect matched but the status of the VLAN hash match depends on the VLAN hash enable (VTHM) bit and VLAN inverse filter (VTIM) bit. Table 20-18. VLAN Match Status VLAN ID (VL field) VL = 0 VL !=0 20.3.7 VLAN Perfect Filter Match Status (VPF) VLAN HASH Enable VLAN Hash Filter VLAN Inverse bit (HPF bit in Match Status (VTHM) Filter Bit (VTIM) EMACFRAMEFLTR) Pass 0 Pass Pass Final VLAN Match Status X X Pass 1 X 0 Pass 1 Fail 1 Pass Pass 1 Pass 1 Fail Pass X X 0 Pass Fail 0 X 0 Fail Fail 1 Fail 0 Fail Fail 1 Pass 0 Pass Fail 0 X 1 Pass Pass X X 1 Fail Fail 1 Pass 1 Fail Fail 1 Fail 1 Pass Source Address, VLAN, and CRC Insertion, Replacement or Deletion The MAC supports the following functions for transmit frames: ■ Source Address Insertion or replacement ■ VLAN Insertion, Replacement or Deletion ■ CRC Replacement 20.3.7.1 Source Address Insertion or Replacement Software can use the SA insertion or replacement feature to instruct the MAC to do the following for transmit frames: 1450 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Insert the content of the MAC Address Registers in the SA field. ■ Replace the content of the SA field with the content of the MAC Address Registers. The software can enable the SA insertion or replacement for all transmitted frames or selective frames: ■ To enable SA insertion or replacement feature for all frames, program the SADDR field of the Ethernet MAC Configuration (EMACCFG) register. ■ To enable SA insertion or replacement for selective frames, program the SA Insertion Control field (TDES1 Bits [31:29]) in the first transmit descriptor of the frame. When Bit 31 of TDES1 is set, the SA Insertion Control field indicates insertion or replacement by MAC Address1 registers. When Bit 31 of TDES1 is reset, it indicates insertion or replacement by MAC Address 0 registers. When SA insertion is enabled, the application should ensure that the frames that are sent to the MAC do not have the SA field. The MAC does not check the presence of SA field in the transmit frame and just inserts the content of MAC Address Registers in the SA field. Similarly, when SA replacement is enabled, the application should ensure that the frames that are sent to the MAC have the SA field. The MAC just replaces the six bytes, following the Destination Address field in the transmit frame, with the content of the MAC Address Registers. 20.3.7.2 VLAN Insertion, Replacement or Deletion The software can use the VLAN insertion, replacement, or deletion feature to instruct the MAC to do the following for transmit frames: ■ Insert or replace the VLAN Type field (C-VLAN or S-VLAN indicated by the CSVL bit of the Ethernet MAC VLAN Tag Inclusion or Replacement (EMACVLNINCREP), MAC offset 0x584) and the VLAN Tag field in the transmit frame with the VLT field of the EMACVLNINCREP register. ■ Delete the VLAN Type and VLAN Tag fields in the transmit frame. The software can enable the VLAN insertion, replacement, or deletion feature for all transmitted frames or selective frames. To enable this function for all transmit frames, configure the VLT field in the EMACVLNINCREP register. When VLAN replacement or deletion is enabled, the MAC checks the presence of the VLAN Type field (0x8100 or 0x88a8), after the Destination address (DA) and SA fields, in the transmit frame. The replace or delete operation does not occur if the VLAN Type field is not detected in the two bytes following the DA and SA fields. However, when VLAN insertion is enabled, the MAC does not check the presence of VLAN Type field in the transmit frame and just inserts the VLAN Type and VLAN Tag fields. 20.3.7.3 CRC Replacement The software can use the CRC replacement feature to instruct the MAC to replace the FCS field in the transmit frame with the CRC computed by the MAC. This feature works on a per-frame basis. The CRC replacement control field in the Transmit Descriptor Word 0 (TDES0) can be programmed to enable this for a frame. This feature is valid only when the Disable CRC control (Bit 27 of TDES0) is enabled. If SA or VLAN insertion control is enabled, the MAC appends or replaces the FCS field with the computed CRC when Disable CRC Control is enabled or disabled, respectively. June 18, 2014 1451 Texas Instruments-Production Data Ethernet Controller Table 20-19. CRC Replacement Based on Bit 27 and Bit 24 of TDES0 Bit 27 (DC) Bit 24 (CRCR) 0 X Description Append CRC When DC= 0, the MAC appends the computed CRC irrespective of the CRCR setting. 20.3.8 1 1 Replace CRC 1 0 No operation (user has appended CRC) Checksum Offload Engine Communication protocols such as TCP and UDP implement checksum fields, which help determine the integrity of data transmitted over a network. Because the most widespread use of Ethernet is to encapsulate TCP and UDP over IP datagrams, the MAC Checksum Offload Engine (COE) supports checksum calculation and insertion in the transmit path, and error detection in the receive path. 20.3.8.1 Transmit Checksum Offload Engine The checksum for TCP, UDP, or ICMP is calculated over a complete frame, and then inserted into its corresponding header field. Because of this requirement this function is enabled only when the TX FIFO is configured for the store-and-forward mode (the TSF bit is set in the EMACDMAOPMODE register). Note: 20.3.8.2 The TX FIFO must be deep enough to store a complete frame before the frame is transferred to the MAC when the checksum offload is being used. If space is not available to accept the programmed burst length of data, the TX/RX Controller starts reading to avoid deadlock. When reading starts, the checksum offload fails and the consequently all succeeding frames may be corrupted because of improper recovery. Therefore, checksum insertion must only be enabled in frames that are less than [2048-((PBL+3)*4)] bytes in size, where PBL is the Programmable Burst Length field in the EMACDMABUSMOD register. IP Header Checksum Engine In IPv4 datagrams, the integrity of the header fields is indicated by the 16-bit Header Checksum field (the eleventh and twelfth bytes of the IPv4 datagram). The checksum offload engine detects an IPv4 datagram when the Ethernet frame's Type field has the value 0x0800 and the IP datagram's Version field has the value 0x4. The input frame's checksum field is ignored during calculation and replaced with the calculated value. IPv6 headers do not have a checksum field. Therefore, the checksum offload does not modify the IPv6 header fields. The result of this IP header checksum calculation is indicated by the IP Header Error status bit in the Transmit status (Bit 16 in TDES0). This status bit is set whenever the values of the Ethernet Type field and the IP header's Version field are not consistent, or when the Ethernet frame does not have enough data, as indicated by the IP header Length field. In other words, this bit is set when an IP header error is asserted under the following circumstances: ■ For IPv4 datagrams: – The received Ethernet type is 0x0800, but the IP header's Version field is not equal to 0x4. – The IPv4 Header Length field indicates a value less than 0x5 (20 bytes). – The total frame length is less than the value given in the IPv4 Header Length field. ■ For IPv6 datagrams: 1452 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller – The Ethernet type is 0x86dd but the IP header Version field is not equal to 0x6. – The frame ends before the IPv6 header (40 bytes) or extension header (as given in the corresponding Header Length field in an extension header) is completely received. If the checksum offload engine detects an IP header error, it still inserts an IPv4 header checksum if the Ethernet Type field indicates an IPv4 payload. 20.3.8.3 Receive Checksum Offload Engine Both IPv4 and IPv6 frames in the received Ethernet frames are detected and processed for data integrity. The receive checksum feature can be enabled by setting the IPC bit of the Ethernet MAC Configuration (EMACCFG) register. The EMAC receiver identifies IPv4 or IPv6 frames by checking for value 0x0800 or 0x86DD, respectively, in the received Ethernet frames' Type field. This identification also applies to single VLAN-tagged frames. The offline receive checksum engine calculates IPv4 header checksums and checks that they match the received IPv4 header checksums. The IP Header Error bit is set for any mismatch between the indicated payload type (Ethernet Type field) and the IP header version, or when the received frame does not have enough bytes, as indicated by the Length field of the IPv4 header or when fewer than 20 bytes are available in an IPv4 or IPv6 header. This engine also identifies a TCP, UDP, or ICMP payload in the received IP datagrams (IPv4 or IPv6) and calculates the checksum of such payloads properly, as defined in the TCP, UDP, or ICMP specifications. This engine includes the TCP, UDP, or ICMPv6 pseudo-header bytes for checksum calculation and checks whether the received checksum field matches the calculated value. The result of this operation is given as a Payload Checksum Error bit in the receive status word. This status bit is also set if the length of the TCP, UDP, or ICMP payload does not match the expected payload length given in the IP header. 20.3.9 MAC Management Counters The MAC Management Counters (MMC) module maintains a set of registers for gathering statistics on the received and transmitted frames. The register set includes a control register for controlling the behavior of the registers, two 32-bit registers containing interrupts generated (one for receive and one for transmit), and two 32-bit registers containing masks for the Interrupt register (one for receive and one for transmit).The MMC counters are free running and start counting when a corresponding frame is received or transmitted. The MMC counter registers provided are as follows: ■ Ethernet MAC Transmit Frame Count for Good and Bad Frames (EMACTXCNTGB) ■ Ethernet MAC Transmit Frame Count for Frames Transmitted after Single Collision (EMACTXCNTSCOL) ■ Ethernet MAC Transmit Frame Count for Frames Transmitted after Multiple Collisions (EMACTXCNTMCOL) ■ Ethernet MAC Transmit Octet Count Good (EMACTXOCTCNTG) ■ Ethernet MAC Receive Frame Count for Good and Bad Frames (EMACRXCNTGB) ■ Ethernet MAC Receive Frame Count for CRC Error Frames (EMACRXCNTCRCERR) ■ Ethernet MAC Receive Frame Count for Alignment Error Frames (EMACRXCNTALGNERR) ■ Ethernet MAC Receive Frame Count for Good Unicast Frames (EMACRXCNTGUNI) June 18, 2014 1453 Texas Instruments-Production Data Ethernet Controller 20.3.10 Power Management Module The power management (PMT) module supports the reception of network remote wake-up frames and AMD Magic Packet™ frames. The PMT module does not perform the clock gate function, but generates interrupts for remote wake-up frames and magic packets that the MAC receives. When the application enables the power-down mode in the PMT module by setting the PWRDWN bit in the Ethernet MAC PMT Control and Status Register (EMACPMTCTLSTAT) register, MAC offset 0x02C, the MAC drops all received frames and does not forward any frame to the TX/RX Controller RxFIFO or the application. The MAC comes out of the power-down mode only when a magic packet or a remote wake-up frame is received and the corresponding detection is enabled. 20.3.10.1 Remote Wake-Up The Remote Wake-Up register bank is made up of eight 32-bit registers. It is loaded by writing the Ethernet MAC Remote Wake-Up Frame Filter (EMACRWUFF) register eight times. To load values in the EMACRWUFF register, the entire register must be written. The first write is assigned to register 0 of the bank, then register 1 and so on. The Ethernet MAC Remote Wake-Up Frame Filter (EMACRWUFF) register is read the same way. The current pointer value of the bank is updated in the Remote Wake-Up FIFO Pointer (RWKPTR) field of the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register. Figure 20-11. Wake-Up Frame Filter Register Bank Filter 0 Byte Mask Filter 1 Byte Mask Filter 2 Byte Mask Filter 3 Byte Mask RSVD Filter 3 Command Filter 3 Offset RSVD Filter 2 Command Filter 2 Offset RSVD Filter 1 Command Filter 1 Offset RSVD Filter 0 Command Filter 0 Offset Filter 1 CRC - 16 Filter 0 CRC - 16 Filter 3 CRC - 16 Filter 2 CRC - 16 Filter n Byte Mask The Filter n Byte Mask registers of the Remote Wake-Up register define the bytes of the frame that are examined by filter n (0, 1, 2, and 3) in order to determine whether or not a frame is a remote wake-up frame. The most significant bit (bit 31) of each mask must be zero. Bits [30:0] are the Byte Mask. If bit, j, of the Byte Mask is set, then the CRC block processes the Filter n Offset + j of the incoming frame; otherwise Filter n Offset + j is ignored. Filter n Command The 4-bit Filter n Command field controls the Filter n operation in the following way: 1454 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Filter n Command Bit 3 specifies the address type of the pattern. When the bit is set, the pattern applies to only multicast frames; when the bit is reset, the pattern applies only to unicast frame. ■ Filter n Command Bit 2 and Bit 1 are reserved. ■ Filter n Command Bit 0 is the enable for Filter n. If bit 0 is not set, filter n is disabled. Filter n Offset The Filter n Offset register defines the offset (within the frame) from which the filter n examines the frames. This 8-bit pattern offset is the offset for the filter n first byte to be examined. The minimum allowed offset is 12, which refers to the 13th byte of the frame. The offset value 0 refers to the first byte of the frame. Filter n CRC-16 The Filter n CRC-16 register contains the CRC_16 value calculated from the pattern and the byte mask programmed to the wake-up filter register block. 20.3.10.2 Remote Wake-Up Frame Detection When the MAC is in sleep mode and the remote wake-up frame enable bit, WUPFREN, is set in the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register, the normal operation is resumed after a remote wake-up frame is received. The application writes all eight wake-up filter registers, by performing eight sequential writes to the Ethernet MAC Remote Wake-Up Frame Filter (EMACRWUFF) register. The Power Management (PMT) block supports four programmable filters that allow support of different receive frame patterns. If the incoming frame passes the address filtering of Filter Command, and if Filter CRC-16 matches the CRC of the incoming pattern, then the MAC identifies the frame as wake-up frame. The Filter Offset determines the offset from which the frame is to be examined. The Filter Byte Mask determines which bytes of the frame must be examined. The 31st bit of Byte Mask must be set to zero. The remote wake-up CRC block determines the CRC value that is compared with Filter CRC-16. The remote wake-up frame is checked only for length error, FCS error, dribble bit error, MII error, and collision. In addition, the remote wake-up frame is checked to ensure that it is not a runt frame. Even if the remote wakeup frame is more than 512 bytes long, if the frame has a valid CRC value, it is considered valid. The remote wake-up frame detection is updated in the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register for every remote wake-up frame received. If the PMT interrupt is enabled in the Ethernet MAC Interrupt Mask (EMACIM) register, a PMT interrupt is asserted and the EMACPMTCTLSTAT register can be read to determine reception of a remote wake-up frame. 20.3.10.3 Magic Packet Detection The magic packet frame is based on a method that uses Advanced Micro Device's magic packet technology to power up the sleeping device on the network. The MAC receives a specific packet of information, called a magic packet, addressed to the node on the network. The MAC checks only those magic packets that are addressed to the MAC or a broadcast address to determine whether these packets meet the wake-up requirements. The magic packets that pass the address filtering (unicast or broadcast) are checked to determine whether they meet the remote wake-up frame data format of 6 bytes of all ones followed by a MAC Address appearing 16 times. The application enables the magic packet wake-up by setting the magic packet enable bit, MGKPKTEN, of the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register. The power management block constantly monitors each frame addressed to the node for a specific magic packet pattern. Each frame received is checked for a 0xFFFF.FFFF.FFFF pattern following the destination and source address field. The power management block then checks the frame for 16 repetitions of the MAC address without any breaks or interruptions. In case of a break in the 16 repetitions of the address, the PMT block again June 18, 2014 1455 Texas Instruments-Production Data Ethernet Controller scans the 0xFFFF.FFFF.FFFF pattern in the incoming frame. The 16 repetitions can be anywhere in the frame, but must be preceded by the synchronization stream (0xFFFF.FFFF.FFFF). The device can also accept a multicast frame, as long as the 16 duplications of the MAC address are detected. If the MAC address of a node is 0x0011.2233.4455, then the MAC scans for the following data sequence: Destination Address Source Address ……………….. FF FF FF FF FF FF 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 00 11 22 33 44 55 …CRC The magic packet detection is updated in the EMACPMTCTLSTAT register for the received magic packet. If the PMT interrupt is enabled in the Ethernet MAC Interrupt Mask (EMACIM) register, a PMT interrupt is asserted and the EMACPMTCTLSTAT register can be read to determine whether a magic packet frame has been received. 20.3.10.4 Power Management Interrupts The PMT interrupt signal can be asserted when a valid remote wake-up frame or magic packet is received. The PMT interrupt signal restores the application clock and TX clock to the MAC. When the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register is read, the PMT interrupt is cleared in the EMACRIS register at least after four clock cycles of RX clock. When software resets the PWRDWN bit in the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register, the MAC comes out of the power-down mode, but this event does not generate at PMT interrupt. 20.3.10.5 Power-Down/Wake-Up Sequence The recommended power-down and wake-up sequence is as follows: 1. Disable the Transmit DMA (if applicable) and wait for any previous frame transmissions to complete. These transmissions can be detected when TI is set in the Ethernet MAC DMA Interrupt Status (EMACDMARIS) register. 2. Disable the MAC transmit and receive state machine by clearing the TE and RE bits in the Ethernet MAC Configuration (EMACCFG) register. 3. Wait until the RX DMA empties all the frames from the Rx FIFO to system memory by polling the RXF field of the Ethernet MAC Status (EMACSTATUS) register. 4. Enable a power management mode by setting the magic packet, global unicast or remote wake-up enable bit in the EMACPMTCTLSTAT register. 5. Enable the MAC receive state machine in the EMACCFG register and enter the Power-Down mode by setting the PWRDWN bit in the EMACPMTCTLSTAT register. 6. On receiving a valid remote wake-up frame, the PMT interrupt is set in the EMACRIS register and the Ethernet MAC exits the Power-Down mode. 7. Read the EMACPMTCTLSTAT register to clear the PMT interrupt, then enable the other modules in the system and resume normal operation. 1456 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 20.3.11 Serial Management Interface The Ethernet MAC has the ability to program the integrated PHY through internal serial MDIO and MDC signals. The MDC signal is a 2.5 MHz clock that is sourced from system clock and then divided down to the required frequency by programming the CR field in the Ethernet MAC MII Address (EMACMIIADDR) register. To access the integrated PHY, the PLA field in the EMACMIIADDR register must be 0x0. 20.3.12 Interrupt Configuration Interrupts can be generated from the MAC as a result of various events in the MAC and sub-modules. MAC interrupts are enabled or disabled in the Ethernet MAC Interrupt Mask (EMACIM) register, MAC offset 0x03C. Each interrupt event can be masked by setting the corresponding mask bit in the EMACIM register. The interrupt register bits in the Ethernet MAC Raw Interrupt Status (EMACRIS) register only indicate the sub-module from which the event is reported. The application must read the corresponding status registers to clear the interrupt. 20.4 Ethernet PHY The integrated PHY supports 10Base-T and 100Base-TX signaling. It integrates all the physical-layer functions needed to transmit and receive data on standard twisted-pair cables. The PHY directly interfaces to the integrated Media Access Controller (MAC). The Ethernet PHY uses mixed-signal processing to perform equalization, data recovery, and error correction to achieve robust operation over CAT5 twisted-pair wiring. It not only meets the requirements of IEEE 802.3, but maintains high margins in terms of alien cross-talk. The following highlights the features of the PHY module: ■ Cable Diagnostics ■ Programmable Fast Link Down Modes ■ Auto-MDIX for 10/100Mbs ■ Energy Detection Mode ■ Serial Management Interface ■ IEEE 802.3u Auto-Negotiation and Parallel Detection ■ IEEE 802.3u ENDEC, 10Base-T Transceivers and Filters ■ IEEE 802.3u PCS, 100Base-TX Transceivers ■ Integrated ANSI X3.263 Compliant TP-PMD Physical Sublayer with Adaptive Equalization and Baseline Wander Compensation ■ Three programmable LEDs that support detection of Link OK, 10/100Mbs activity, TX/RX transfers, collisions and full duplex mode 20.4.1 Integrated PHY Block Diagram The following figure shows the internal PHY integration. Note that the reference clock input comes from an external 25 MHz ± 50 ppm crystal or oscillator connected to the MOSC signals. June 18, 2014 1457 Texas Instruments-Production Data Ethernet Controller Figure 20-12. Integrated PHY Diagram TRANSMIT BLOCK TX 10BASE-T and 100BASE-TX 25 MHz MOSC Cable Diagnostics DAC EN0TXOP / EN0TXON AutoNegotiation State Machine Clock Generation Auto MDIX EN0RXIP / EN0RXIN RECEIVE BLOCK RX 10BASE-T and 100BASE-TX EN0MDC EN0MDIO 20.4.2 Serial Management Interface PHY Registers ADC Extended PHY Registers LED Drivers EN0LEDn Functional Description The following sections describe the functional characteristics of the integrated PHY. 20.4.2.1 Auto-Negotiation The Ethernet PHY can auto-negotiate to operate in 10Base-T or 100Base-TX. When the Ethernet PHY is enabled or on the deassertion of software reset, the Ethernet MAC Peripheral Configuration Register (EMACPC) register, offset 0xFC4, is configured such that auto-negotiation is enabled and the auto negotiation mode (ANMODE) bit field is programmed to 10Base-T,Half/Full-Duplex 100Base-TX, Half/Full-Duplex. With auto-negotiation enabled, the PHY negotiates with the link partner to determine the speed and duplex mode with which to operate. If the link partner is unable to auto-negotiate, the PHY goes into parallel-detect mode to determine the speed of the link partner. Under parallel-detect mode, the duplex mode is fixed at half-duplex. The PHY supports four different Ethernet protocols (10Mbs Half-Duplex, 10Mbs Full-Duplex, 100Mbs Half-Duplex, and 100Mbs Full-Duplex). Auto-Negotiation selects the highest performance protocol based on the advertised ability of the Link Partner. If a different auto-negotiation configuration is required other than the reset initialization values, the application can customize the configuration of the ANEN bit and ANMODE bit field as described in “Custom Configuration” on page 1466. The values of ANEN and ANMODE determine whether the PHY is forced into a specific mode, or if Auto-negotiation advertises a specific ability (or abilities) as listed in Table 20-20 on page 1458 and Table 20-21 on page 1459: Table 20-20. Forced Mode Configurations ANEN value ANMODE Forced Mode 0 0x0 10Base-T, Half-Duplex 0 0x1 10Base-T, Full-Duplex 0 0x2 100Base-TX, Half-Duplex 0 0x3 100Base-TX, Full-Duplex 1458 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 20-21. Advertised Mode Configurations 20.4.2.2 ANEN value ANMODE Advertised Mode 1 0x0 10Base-T, Half/Full-Duplex 1 0x1 100Base-TX, Half/Full-Duplex 1 0x2 10Base-T, Half Duplex 100Base-TX, Half Duplex 1 0x3 10Base-T, Half/Full-Duplex 100Base-TX, Half/Full-Duplex Auto-MDIX The PHY automatically determines whether or not it needs to cross over between pairs so that an external crossover cable is not required. If the PHY communicates with a device that implements MDI/MDIX crossover, a random algorithm as described in IEEE 802.3 determines which device performs the crossover. Auto-MDIX is enabled by default at reset. If a different auto-MDIX configuration is required other than the reset initialization, the application can customize the configuration as described in “Custom Configuration” on page 1466. Neither Auto- Negotiation nor Auto-MDIX is required to be enabled in forcing crossover of the MDI pairs. Auto-MDIX can be used in the forced 100Base-TX mode. Because in modern networks all the nodes are 100Base-TX, having the Auto-MDIX working in the forced 100Base-TX mode resolves the link faster without the need for the long Auto-Negotiation period. 20.4.2.3 Isolate Mode The PHY can be put into Isolate mode by writing ISOLATE bit of the Ethernet PHY Basic Mode Control - MR0 (EPHYBMCR) register, address 0x000. When in the Isolate mode, the PHY does not respond to packet data present at the internal interface to the Ethernet MAC. When in isolate mode, the PHY continues to respond to all management transactions and the PMD output pair does not transmit packet data, but continues to source 100Base-TX scrambled idles or 10Base-T normal link pulses. The PHY can auto-negotiate or parallel detect on the receive signal at the PMD input pair. A valid link can be established for the receiver even when the PHY is in Isolate mode. 20.4.2.4 LED Interface The PHY supports three configurable Light Emitting Diode (LED) pins to indicate link status of a port. The Ethernet PHY LED Configuration - MR37 (EPHYLEDCFG) register, address 0x025 can be used to assign different functions to each LED. Each LED can be configured to be active during one of these events: ■ Link OK (0x0) ■ RX/TX Activity (0x1) ■ TX Activity (0x2) ■ RX Activity (0x3) ■ Collision (0x4) ■ 100-BASE TX speed (0x5) ■ 10-Base TX speed (0x6) ■ Full Duplex (0x7) ■ Link OK/Blink on TX/RX Activity (0x8) June 18, 2014 1459 Texas Instruments-Production Data Ethernet Controller At reset, LED0 is initialized to display Link OK and LED1 and LED 2 are initialized to the RX/TX activity encoding. The blink rate of the LEDs can be set by programming the BLINKRATE bit field of the Ethernet PHY LED Control - MR24 (EPHYLEDCR) register, address 0x018 20.4.2.5 PHY Address The integrated PHY's address is 0x00. To access the integrated PHY registers through the internal MAC's MDIO interface, the PLA bit field of the Ethernet MAC MII Address (EMACMIIADDR) register must be 0x00 and the MII field should be programmed to the desired address value. 20.4.2.6 Serial Management Interface The Ethernet MAC module has the capability of programming the integrated PHY registers and extended registers through an internal Serial Management Interface (SMI). The SMI is compatible with IEEE802.3-2002 clause 22. The SMI includes an MDC management clock input and management MDIO data pin to the Ethernet PHY. The internal MDC clock is sourced by the system clock and then divided down to the required 2.5 MHz maximum clock frequency by setting the CR bit in the Ethernet MAC MII Address (EMACMIIADDR) register. The MDC is not expected to be continuous, and can be turned off by the external management entity when the bus is idle. The MDIO is sourced by the integrated MAC and by the PHY. The data on the MDIO pin is latched on the rising edge of the MDC clock. The PHY's physical address is 0x00. 20.4.2.7 Extended Address Space Access The PHY SMI function supports read/write accesses to the extended register set using Ethernet PHY Register Control - MR13 (EPHYREGCTL) register and the Ethernet PHY Address or Data - MR14 (EPHYADDAR) registers. Accessing the standard register set, MDIO registers 0 to 31, can be performed using the normal direct MDIO access or the indirect method, except for the EPHYREGCTL (0x00D) and the EPHYADDAR (0x00E) which can be accessed only using the normal MDIO transaction. The SMI function ignores indirect accesses to these registers. The EPHYREGCTL register is the MDIO Manageable MMD access control. In general, register EPHYREGCTL[4:0] is the device address DEVAD that directs any accesses of EPHYADDAR register to the appropriate MMD. Specifically, the PHY uses the vendor specific DEVAD[4:0] = 0xF for accesses. All accesses through registers EPHYREGCTL and EPHYADDAR registers should use this DEVAD. Transactions with other DEVAD are ignored. The EPHYREGCTL[15:14] register holds the access function: ■ EPHYREGCTL[15:14] = 0x0: A write to EPHYADDAR modifies the extended register set address register. This address register must be initialized in order to access any of the registers within the extended register set. ■ EPHYREGCTL[15:14] = 0x1: A read/write to EPHYADDAR operates on the register within the extended register set selected (pointed to) by the value in the address register. The address register contents (pointer) remain unchanged. ■ EPHYREGCTL[15:14] = 0x2: A read/write to EPHYADDAR operates on the register within the extended register set selected (pointed to) by the value in the address register. After that access is complete, for both reads and writes, the value in the address register is incremented. ■ EPHYREGCTL[15:14] = 0x3: A read/write to EPHYADDAR operates on the register within the extended register set selected (pointed to) by the value in the address register. After that access is complete, for write accesses only, the value in the address register is incremented. For read accesses, the value of the address register remains unchanged. 1460 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller The following sections describe how to perform operations on the extended register set using the EPHYREGCTL and EPHYADDAR registers. Write to PHY Registers The following describes the steps to write to a PHY register. 1. Check the MIIB bit in the EMACMIIADDR register to identify if the MII interface is busy. When the MIIB bit is 0, the MII interface is available to write to the PHY registers. 2. Write the data to be written to the PHY register in the EMACMIIDATA register. 3. Initiate write by programming the EMACMIIADDR register fields as follows: ■ PLA: Physical Layer Address of the PHY. The integrated PHY's address is 0x0. ■ MII: Address of the PHY register to be written. ■ CR: Clock Reference for the MDIO interface. ■ MIIW: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed. ■ MIIB: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a write operation. The EMAC clears this bit when the write has been transmitted. Write to Extended PHY Registers The following describes the steps to write to an extended PHY register. 1. Check the MIIB bit in the EMACMIIADDR register to identify if the MII interface is busy. When the MIIB bit is 0, the MII interface is available to write to the PHY registers. 2. The EMACMIIDATA register should be written with the value to be passed into the EPHYREGCTL register. The EPHYREGCTL register is used for extended PHY register accesses. The DEVAD field of the EPHYREGCTL register identifies the device address, which is 0x1F, for the integrated PHY. The FUNC field of the EPHYREGCTL register should be set to 0x0 to indicate a write to an extended register address. 3. Initiate write by programming the EMACMIIADDR register fields as follows: ■ PLA: Physical Layer Address of the PHY. The integrated PHY's address is 0x0. ■ MII: Address of the PHY register to be written. In this case, it should be the address of the EPHYREGCTL register, 0xD. ■ CR: Clock Reference for the MDIO interface. ■ MIIW: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed. ■ MIIB: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a write operation. The EMAC clears this bit when the write has been transmitted. 4. Check the MIIB bit in the EMACMIIADDR register to identify if the MII interface is busy. When the MIIB bit is 0, the MII interface is available to write to the PHY registers. June 18, 2014 1461 Texas Instruments-Production Data Ethernet Controller 5. The EMACMIIDATA register should be written with the address of the extended register to be accessed. This value is written to the EPHYADDAR register. 6. Initiate write by writing the EMACMIIADDR register fields: ■ PLA: Physical Layer Address of the PHY. The integrated PHY's address is 0x0. ■ MII: Address of the PHY register to be written. In this case, it should be the address of the EPHYADDAR register, 0xE. ■ CR: Clock Reference for the MDIO interface. ■ MIIW: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed. ■ MIIB: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a write operation. The EMAC clears this bit when the write has been transmitted. 7. Check the MIIB bit in the EMACMIIADDR register to identify if the MII interface is busy. When the MIIB bit is 0, the MII interface is available to write to the PHY registers. 8. The EMACMIIDATA register should be written with the value to be passed into the EPHYREGCTL register. The DEVAD field of the EPHYREGCTL register identifies the device address, which is 0x1F, for the integrated PHY. The FUNC field of the EPHYREGCTL register should be set to 0x1 to indicate a write to an extended register address with no increment. 9. Initiate write by writing the EMACMIIADDR register fields: ■ PLA: Physical Layer Address of the PHY. The integrated PHY's address is 0x0. ■ MII: Address of the PHY register to be written. In this case, it should be the address of the EPHYADDAR register, 0xD. ■ CR: Clock Reference for the MDIO interface. ■ MIIW: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed. ■ MIIB: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a write operation. The EMAC clears this bit when the write has been transmitted. 10. Check the MIIB bit in the EMACMIIADDR register to identify if the MII interface is busy. When the MIIB bit is 0, the MII interface is available to write to the PHY registers. 11. The EMACMIIDATA register should be programmed with the data to be written to the EPHYADDAR register which is transferred to the previously selected extended PHY register. 12. Initiate write by writing the EMACMIIADDR register fields: ■ PLA: Physical Layer Address of the PHY. The integrated PHY's address is 0x0. ■ MII: Address of the PHY register to be written. In this case, it should be the address of the EPHYADDAR register, 0xD. ■ CR: Clock Reference for the MDIO interface. ■ MIIW: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed. 1462 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ MIIB: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a write operation. The EMAC clears this bit when the write has been transmitted. Read from PHY Registers The following describes the steps to read from an extended PHY register. 1. Check the MIIB bit in the EMACMIIADDR register to identify if the MII interface is busy. When the MIIB bit is 0, the MII interface is available to read to the PHY registers. 2. Initiate the read by writing the EMACMIIADDR register fields: ■ PLA: Physical Layer Address of the PHY. The integrated PHY's address is 0x0. ■ MII: Register address of PHY register to be written. ■ CR: Clock Reference for the MDIO interface. ■ MIIW: Write/Read Initiation. This bit is programmed to a 0 to indicate that a read operation is to be executed. ■ MIIB: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a read operation. The EMAC clears this bit when the write has been transmitted. 3. Wait for the MII interface to complete the read by polling the MIIB bit. 4. When the MIIB is clear, read the contents of the EMACMIIDATA register. Read from Extended PHY Registers The following describes the steps to read from an extended PHY register. 1. Check the MIIB bit in the EMACMIIADDR register to identify if the MII interface is busy. When the MIIB bit is 0, the MII interface is available to read to the PHY registers. 2. Initiate the read by writing the EMACMIIADDR register fields: ■ PLA: Physical Layer Address of the PHY. The integrated PHY's address is 0x0. ■ MII: Register address of PHY register to be written. ■ CR: Clock Reference for the MDIO interface. ■ MIIW: Write/Read Initiation. This bit is programmed to a 0 to indicate that a read operation is to be executed. ■ MIIB: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a read operation. The EMAC clears this bit when the write has been transmitted. 3. Wait for the write to complete by polling the MIIB bit. 4. When the MIIB is clear, read the contents of the EMACMIIDATA register. 20.4.3 Interface Configuration Figure 20-13 on page 1464 shows the proper method for interfacing the Ethernet Controller to a 10/100BASE-T Ethernet jack. June 18, 2014 1463 Texas Instruments-Production Data Ethernet Controller Figure 20-13. Interface to Ethernet Jack 3.3V 3.3V 0.1mF 3.3V 0.1mF 49.9Ω 1% Tiva Cortex-M4 Microcontroller 3.3V 49.9Ω 1% 49.9Ω 1% 49.9Ω 1% HX1188FNL EN0TXOP EN0TXON EN0RXIP EN0RXIN SLVU2.8-4 1 16 1 2 15 3 14 2 6 11 3 7 10 8 9 4 RJ45 – NoMag 8 1 TX+ 2 TX- 7 3 RX+ 6 4 TERM1A 5 TERM1B 6 RX- 7 TERM2A 8 TERM2B 5 RBIAS 75Ω 4.87kΩ 1% 75Ω 75Ω CHASIS 10 CHASIS 9 75Ω 0.1mF 0.1mF 1MΩ 1000pF 2000V 4700pF 2000V NOTE: The 0.1mF capacitors on pins 2 and 7 of the HX1188FNL should be located near the physical pins of the transformer. The Ethernet PHY is designed to work with transformers that meet the IEEE 802.3 standard. To utilize the Auto-MDIX (AMDIX) capability of the Ethernet PHY, a symmetrical transformer is recommended. The Pulse HX1188 transformer has been tested and is known to successfully interface to the Ethernet PHY. 20.5 Note: If the PHY is not to be used, then the EN0RXIN/EN0TX0N EN0RXIP/EN0TX0P pair should be left unconnected and the RBIAS pin should be unconnected as well. Note: When entering hibernation in VDD3ON mode, the supply rails to the Ethernet resistors R1, R2, R3, R4 found in Figure 20-13 on page 1464 must be switched off. Initialization and Configuration The MAC module and registers are enabled and powered at reset. When reset has completed, the application should enable the clock to the Ethernet MAC by setting the R0 bit in the Ethernet Controller Run Mode Clock Gating Control (RCGCEMAC) register at System Control Module offset 0x69C. When the PREMAC register, at System Control offset 0xA9C reads as 0x0000.0001, the EMAC registers are ready to be accessed. The Initialization for the DMA for the Ethernet MAC is as follows: 1. Write to the Ethernet MAC DMA Bus Mode (EMACDMABUSMOD) register to set Host bus parameters. 2. Write to the Ethernet MAC DMA Interrupt Mask Register (EMACDMAIM) register to mask unnecessary interrupt causes. 3. Create the transmit and receive descriptor lists and then write to the Ethernet MAC Receive Descriptor List Address (EMACRXDLADDR) register and the Ethernet MAC Transmit 1464 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Descriptor List Address (EMACTXDLADDR) register providing the DMA with the starting address of each list. 4. Write to the Ethernet MAC Frame Filter (EMACFRAMEFLTR) register, the Ethernet MAC Hash Table High (EMACHASHTBLH) and the Ethernet MAC Hash Table Low (EMACHASHTBLL) for desired filtering options. 5. Write to the Ethernet MAC Configuration Register (EMACCFG) to configure the operating mode and enable the transmit operation. 6. Program Bit 15 (PS) and Bit 11 (DM) of the EMACCFG register based on the line status received or read from the PHY status register after auto-negotiation. 7. Write to the Ethernet MAC DMA Operation Mode (EMACDMAOPMODE) register to set Bits 13 and 1 to start transmission and reception. 8. Write to the EMACCFG register to enable the receive operation. The Transmit and Receive engines enter the Running state and attempt to acquire descriptors from the respective descriptor lists. The Receive and Transmit engines then begin processing Receive and Transmit operations. The Transmit and Receive processes are independent of each other and can be started or stopped separately. 20.5.1 Ethernet PHY Initialization After reset, when the EMAC is powered and enabled, the EMACPC register default reset value may be sampled and used to configure the PHY. The results of this configuration can also be read in the following EPHY registers: ■ EPHYBMCR register (MR0) ■ EPHYCFG1 register (MR9) ■ EPHYCFG2 register (MR10) ■ EPHYCFG3 register (MR11) ■ EPHYCTL register (MR25) The mappings of the EMACPC register bits to the PHY register and bits are as follows: Table 20-22. EMACPC to PHY Register Mapping EMACPC Register Bit Corresponding PHY Register Corresponding PHY Bit (Bit No.) PHYEXT N/A N/A DIGRESTART N/A N/A NIBDETDIS EPHYCFG2 ODDNDETDIS (1) RXERIDLE EPHYCFG2 RXERRIDLE (2) ISOMILL EPHYCFG2 ISOMILL (3) LRR EPHYCFG1 LLR (7) TDRRUN EPHYCFG1 TDRAR (8) FASTLDMODE EPHYCFG3 FLDWNM (4:0) POLSWAP EPHYCFG3 POLSWAP (7) MDISWAP EPHYCFG3 MDIMDIXS (6) June 18, 2014 1465 Texas Instruments-Production Data Ethernet Controller Table 20-22. EMACPC to PHY Register Mapping (continued) EMACPC Register Bit Corresponding PHY Register Corresponding PHY Bit (Bit No.) RBSTMDIX EPHYCFG1 RAMDIX (5) FASTMDIX EPHYCFG1 FAMDIX (6) MDIXEN EPHYCTL AUTOMDI (15) FASTRXDV EPHYCFG1 FRXDVDET (1) FASTLUPD EPHYCFG2 FLUPPD (6) EXTFD EPHYCFG2 EXTFD (5) FASTANEN EPHYCFG1 FASTANEN (4) FASTANSEL EPHYCFG1 FANSEL (3:2) ANEN EPHYBMCR ANEN ANMODE N/A N/A PHYHOLD N/A N/A The MAC module and registers are enabled and powered at reset. When reset has completed and the clock to the Ethernet MAC is enabled by setting the R0 bit in the Ethernet Controller Run Mode Clock Gating Control (RCGCEMAC) register at System Control Module offset 0x69C, the application has the option to enable the PHY with its default interface configuration (as defined by the Ethernet MAC Peripheral Configuration Register (EMACPC) register) or with a custom configuration. 20.5.1.1 Default Configuration To enable the Ethernet PHY with its default configuration, the steps are as follows: 1. To hold the Ethernet PHY from transmitting energy on the line during configuration, set the PHYHOLD bit to 1 in the EMACPC register. 2. Enable the clock to the PHY module by writing 0x0000.0001 to the Ethernet PHY Run Mode Clock Gating Control (RCGCEPHY) register at offset 0x630. When the R0 bit reads as 1 in the PREPHY register at System Control offset 0xA30, continue initialization. 3. Enable power to the Ethernet PHY by setting the P0 bit in the PCEPHY register at System Control offset 0x930. When the R0 bit reads as 1 in the PREPHY register at System Control offset 0xA30, the PHY registers are ready for programming. 20.5.1.2 Custom Configuration If a custom configuration of the Ethernet PHY is required, the application can program the configuration registers after reset. The steps for custom configuration are as follows: 1. To hold the PHY from transmitting energy on the line during configuration, set the PHYHOLD bit to 1 in the EMACPC register. 2. Enable the clock to the PHY module by writing 0x0000.0001 to the Ethernet PHY Run Mode Clock Gating Control (RCGCEPHY) register at offset 0x630. When the R0 bit reads as 1 in the PREPHY register at System Control offset 0xA30, continue initialization. 3. Enable power to the Ethernet PHY by setting the P0 bit in the PCEPHY register at System Control offset 0x930. When the R0 bit reads as 1 in the PREPHY register at System Control offset 0xA30, the PHY registers are ready for programming. 1466 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 4. Once the Ethernet PHY Peripheral Ready (PREPHY) register reads 0x0000.0001, software can write the EMACPC register with the required value. 5. After software configuration is complete, the application must set the DONE bit in the Ethernet PHY Configuration 1 (EPHYCFG1) register at offset 0x009. Note: 20.6 If a software reset is asserted to the PHY afterwards through the SREPHY register, the custom configuration is lost and the steps described above must be repeated. Register Map Table 20-23 on page 1467 lists the Ethernet Controller MAC and PHY registers. For the MAC registers, the offset listed is a hexadecimal increment to the MAC base address of 0x400E.C000. PHY registers are accessed through the EMACMIIADDR register thus the base address is n/a (not applicable) and noted as such above the register descriptions. The IEEE 802.3 standard specifies a register set for controlling and gathering status from the PHY layer. The registers are collectively known as the MII Management registers. Table 20-23 on page 1467 also lists these MII Management registers for interfacing to the internal PHY. All addresses given are absolute and are written directly to the MII field of the Ethernet MAC MII Address (EMACMIIADDR) register, offset 0x010. The PLA value of the EMACMIIADDR register for the internal PHY is 0x00. Table 20-23. Ethernet Register Map Offset Name Type Reset Description See page Ethernet MAC (Ethernet Offset) 0x000 EMACCFG RW 0x0000.8000 Ethernet MAC Configuration 1471 0x004 EMACFRAMEFLTR RW 0x0000.0000 Ethernet MAC Frame Filter 1478 0x008 EMACHASHTBLH RW 0x0000.0000 Ethernet MAC Hash Table High 1482 0x00C EMACHASHTBLL RW 0x0000.0000 Ethernet MAC Hash Table Low 1483 0x010 EMACMIIADDR RW 0x0000.0000 Ethernet MAC MII Address 1484 0x014 EMACMIIDATA RW 0x0000.0000 Ethernet MAC MII Data Register 1486 0x018 EMACFLOWCTL RW 0x0000.0000 Ethernet MAC Flow Control 1487 0x01C EMACVLANTG RW 0x0000.0000 Ethernet MAC VLAN Tag 1489 0x024 EMACSTATUS RO 0x0000.0000 Ethernet MAC Status 1491 0x028 EMACRWUFF RW 0x0000.0000 Ethernet MAC Remote Wake-Up Frame Filter 1494 0x02C EMACPMTCTLSTAT RW 0x0000.0000 Ethernet MAC PMT Control and Status Register 1495 0x038 EMACRIS RO 0x0000.0000 Ethernet MAC Raw Interrupt Status 1497 0x03C EMACIM RW 0x0000.0000 Ethernet MAC Interrupt Mask 1499 0x040 EMACADDR0H RW 0x8000.FFFF Ethernet MAC Address 0 High 1500 0x044 EMACADDR0L RW 0xFFFF.FFFF Ethernet MAC Address 0 Low Register 1501 0x048 EMACADDR1H RW 0x0000.FFFF Ethernet MAC Address 1 High 1502 June 18, 2014 1467 Texas Instruments-Production Data Ethernet Controller Table 20-23. Ethernet Register Map (continued) Description See page 0xFFFF.FFFF Ethernet MAC Address 1 Low 1504 RW 0x0000.FFFF Ethernet MAC Address 2 High 1505 EMACADDR2L RW 0xFFFF.FFFF Ethernet MAC Address 2 Low 1507 0x058 EMACADDR3H RW 0x0000.FFFF Ethernet MAC Address 3 High 1508 0x05C EMACADDR3L RW 0xFFFF.FFFF Ethernet MAC Address 3 Low 1510 0x0DC EMACWDOGTO RW 0x0000.0000 Ethernet MAC Watchdog Timeout 1511 0x100 EMACMMCCTRL RW 0x0000.0000 Ethernet MAC MMC Control 1512 0x104 EMACMMCRXRIS RO 0x0000.0000 Ethernet MAC MMC Receive Raw Interrupt Status 1515 0x108 EMACMMCTXRIS R 0x0000.0000 Ethernet MAC MMC Transmit Raw Interrupt Status 1517 0x10C EMACMMCRXIM RW 0x0000.0000 Ethernet MAC MMC Receive Interrupt Mask 1519 0x110 EMACMMCTXIM RW 0x0000.0000 Ethernet MAC MMC Transmit Interrupt Mask 1521 0x118 EMACTXCNTGB RO 0x0000.0000 Ethernet MAC Transmit Frame Count for Good and Bad Frames 1523 0x14C EMACTXCNTSCOL RO 0x0000.0000 Ethernet MAC Transmit Frame Count for Frames Transmitted after Single Collision 1524 0x150 EMACTXCNTMCOL RO 0x0000.0000 Ethernet MAC Transmit Frame Count for Frames Transmitted after Multiple Collisions 1525 0x164 EMACTXOCTCNTG RO 0x0000.0000 Ethernet MAC Transmit Octet Count Good 1526 0x180 EMACRXCNTGB RO 0x0000.0000 Ethernet MAC Receive Frame Count for Good and Bad Frames 1527 0x194 EMACRXCNTCRCERR RO 0x0000.0000 Ethernet MAC Receive Frame Count for CRC Error Frames 1528 0x198 EMACRXCNTALGNERR RO 0x0000.0000 Ethernet MAC Receive Frame Count for Alignment Error Frames 1529 0x1C4 EMACRXCNTGUNI RO 0x0000.0000 Ethernet MAC Receive Frame Count for Good Unicast Frames 1530 0x584 EMACVLNINCREP RW 0x0000.0000 Ethernet MAC VLAN Tag Inclusion or Replacement 1531 0x588 EMACVLANHASH RW 0x0000.0000 Ethernet MAC VLAN Hash Table 1533 0x700 EMACTIMSTCTRL RW 0x0000.2000 Ethernet MAC Timestamp Control 1534 0x704 EMACSUBSECINC RW 0x0000.0000 Ethernet MAC Sub-Second Increment 1538 0x708 EMACTIMSEC RO 0x0000.0000 Ethernet MAC System Time - Seconds 1539 0x70C EMACTIMNANO RO 0x0000.0000 Ethernet MAC System Time - Nanoseconds 1540 0x710 EMACTIMSECU RW 0x0000.0000 Ethernet MAC System Time - Seconds Update 1541 0x714 EMACTIMNANOU RW 0x0000.0000 Ethernet MAC System Time - Nanoseconds Update 1542 0x718 EMACTIMADD RW 0x0000.0000 Ethernet MAC Timestamp Addend 1543 Offset Name Type Reset 0x04C EMACADDR1L RW 0x050 EMACADDR2H 0x054 1468 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 20-23. Ethernet Register Map (continued) Description See page 0x0000.0000 Ethernet MAC Target Time Seconds 1544 RW 0x0000.0000 Ethernet MAC Target Time Nanoseconds 1545 EMACHWORDSEC RW 0x0000.0000 Ethernet MAC System Time-Higher Word Seconds 1546 0x728 EMACTIMSTAT RO 0x0000.0000 Ethernet MAC Timestamp Status 1547 0x72C EMACPPSCTRL RW 0x0000.0000 Ethernet MAC PPS Control 1548 0x760 EMACPPS0INTVL RW 0x0000.0000 Ethernet MAC PPS0 Interval 1551 0x764 EMACPPS0WIDTH RW 0x0000.0000 Ethernet MAC PPS0 Width 1552 0xC00 EMACDMABUSMOD RW 0x0002.0101 Ethernet MAC DMA Bus Mode 1553 0xC04 EMACTXPOLLD WO 0x0000.0000 Ethernet MAC Transmit Poll Demand 1557 0xC08 EMACRXPOLLD WO 0x0000.0000 Ethernet MAC Receive Poll Demand 1558 0xC0C EMACRXDLADDR RW 0x0000.0000 Ethernet MAC Receive Descriptor List Address 1559 0xC10 EMACTXDLADDR RW 0x0000.0000 Ethernet MAC Transmit Descriptor List Address 1560 0xC14 EMACDMARIS RW 0x0000.0000 Ethernet MAC DMA Interrupt Status 1561 0xC18 EMACDMAOPMODE RW 0x0000.0000 Ethernet MAC DMA Operation Mode 1567 0xC1C EMACDMAIM RW 0x0000.0000 Ethernet MAC DMA Interrupt Mask Register 1572 0xC20 EMACMFBOC RO 0x0000.0000 Ethernet MAC Missed Frame and Buffer Overflow Counter 1575 0xC24 EMACRXINTWDT RW 0x0000.0000 Ethernet MAC Receive Interrupt Watchdog Timer 1576 0xC48 EMACHOSTXDESC R 0x0000.0000 Ethernet MAC Current Host Transmit Descriptor 1577 0xC4C EMACHOSRXDESC RO 0x0000.0000 Ethernet MAC Current Host Receive Descriptor 1578 0xC50 EMACHOSTXBA R 0x0000.0000 Ethernet MAC Current Host Transmit Buffer Address 1579 0xC54 EMACHOSRXBA R 0x0000.0000 Ethernet MAC Current Host Receive Buffer Address 1580 0xFC0 EMACPP RO 0x0000.0103 Ethernet MAC Peripheral Property Register 1581 0xFC4 EMACPC RW 0x0080.040E Ethernet MAC Peripheral Configuration Register 1582 0xFC8 EMACCC RO 0x0000.0000 Ethernet MAC Clock Configuration Register 1586 0xFD0 EPHYRIS RO 0x0000.0000 Ethernet PHY Raw Interrupt Status 1587 0xFD4 EPHYIM RW 0x0000.0000 Ethernet PHY Interrupt Mask 1588 0xFD8 EPHYMISC RW1C 0x0000.0000 Ethernet PHY Masked Interrupt Status and Clear 1589 Offset Name Type Reset 0x71C EMACTARGSEC RW 0x720 EMACTARGNANO 0x724 MII Management (Accessed through the EMACMIIADDR Register) - EPHYBMCR RW 0x3100 Ethernet PHY Basic Mode Control - MR0 1590 - EPHYBMSR RO 0x7849 Ethernet PHY Basic Mode Status - MR1 1592 - EPHYID1 R 0x2000 Ethernet PHY Identifier Register 1 - MR2 1595 June 18, 2014 1469 Texas Instruments-Production Data Ethernet Controller Table 20-23. Ethernet Register Map (continued) Offset Name Type Reset Description See page - EPHYID2 R 0xA221 Ethernet PHY Identifier Register 2 - MR3 1596 - EPHYANA RW 0x01E1 Ethernet PHY Auto-Negotiation Advertisement - MR4 1597 - EPHYANLPA RO 0x0000 Ethernet PHY Auto-Negotiation Link Partner Ability - MR5 1599 - EPHYANER RO 0x0004 Ethernet PHY Auto-Negotiation Expansion - MR6 1601 - EPHYANNPTR RW 0x2001 Ethernet PHY Auto-Negotiation Next Page TX - MR7 1602 - EPHYANLNPTR RO 0x0000 Ethernet PHY Auto-Negotiation Link Partner Ability Next Page - MR8 1604 - EPHYCFG1 RW 0x0000 Ethernet PHY Configuration 1 - MR9 1606 - EPHYCFG2 RW 0x0004 Ethernet PHY Configuration 2 - MR10 1609 - EPHYCFG3 RW 0x0000 Ethernet PHY Configuration 3 - MR11 1611 - EPHYREGCTL WO 0x0000 Ethernet PHY Register Control - MR13 1613 - EPHYADDAR WO 0x0000 Ethernet PHY Address or Data - MR14 1615 - EPHYSTS RO 0x0002 Ethernet PHY Status - MR16 1616 - EPHYSCR RW 0x0103 Ethernet PHY Specific Control- MR17 1619 - EPHYMISR1 RW 0x0000 Ethernet PHY MII Interrupt Status 1 - MR18 1622 - EPHYMISR2 RW 0x0000 Ethernet PHY MII Interrupt Status 2 - MR19 1625 - EPHYFCSCR RO 0x0000 Ethernet PHY False Carrier Sense Counter - MR20 1628 - EPHYRXERCNT RO 0x0000.0000 Ethernet PHY Receive Error Count - MR21 1629 - EPHYBISTCR RW 0x0100 Ethernet PHY BIST Control - MR22 1630 - EPHYLEDCR RW 0x0400 Ethernet PHY LED Control - MR24 1633 - EPHYCTL RW 0x8000 Ethernet PHY Control - MR25 1634 - EPHY10BTSC RW 0x0000 Ethernet PHY 10Base-T Status/Control - MR26 1636 - EPHYBICSR1 RW 0x007D Ethernet PHY BIST Control and Status 1 - MR27 1638 - EPHYBICSR2 RW 0x05EE Ethernet PHY BIST Control and Status 2 - MR28 1639 - EPHYCDCR RO 0x0102 Ethernet PHY Cable Diagnostic Control - MR30 1640 - EPHYRCR RW 0x0000 Ethernet PHY Reset Control - MR31 1641 - EPHYLEDCFG RW 0x0000.0510 Ethernet PHY LED Configuration - MR37 1642 20.7 Ethernet MAC Register Descriptions This section lists and describes the MAC registers, in numerical order by address offset. Also see “Ethernet PHY Register Descriptions” on page 1589. 1470 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: Ethernet MAC Configuration (EMACCFG), offset 0x000 The EMACCFG register establishes receive and transmit operating modes. Note that the TWOKPEN bit is only applicable when the JFEN bit is 0. Ethernet MAC Configuration (EMACCFG) Base 0x400E.C000 Offset 0x000 Type RW, reset 0x0000.8000 31 30 reserved Type Reset Type Reset 29 28 SADDR 27 26 TWOKPEN reserved 25 24 23 22 21 20 19 18 17 CST reserved WDDIS JD reserved JFEN RO 0 RW 0 RW 0 RW 0 RW 0 RO 0 RW 0 RO 0 RW 0 RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 PS FES DRO LOOPBM DUPM IPC DR reserved ACS DC TE RE RO 1 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 BL RW 0 IFG 16 DISCRS PRELEN RW 0 RW 0 Bit/Field Name Type Reset Description 31 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 30:28 SADDR RW 0x0 Source Address Insertion or Replacement Control Bit 30 specifies whether MAC address 0 or 1 registers are used during insertion or replacement for all transmitted frames. Thus for encodings 0x2-0x3, where the most significant bit is 0, the Ethernet MAC Address 0 registers are used. For encodings 0x6-0x7, the Ethernet MAC Address 1 registers are used. Bits [29:28] indicate insertion or replacement. If the value is 0x2 insertion is indicated and if the value is 0x3 replacement is indicated. Value Description 0x0-0x1 reserved 0x2 The Ethernet MAC inserts the content of the Ethernet MAC Address 0 (EMACADDR0x) registers in the SA field of all transmitted frames. 0x3 The Ethernet MAC replaces the content of the Ethernet MAC Address 0 (EMACADDR0x) registers in the SA field of all transmitted frames. 0x4-0x5 reserved 0x6 The MAC inserts the content of the Ethernet MAC Address 1 (EMACADDR1x) registers in the source address (SA) field for all transmitted frames. 0x7 The MAC replaces the content of the Ethernet MAC Address 1(EMACADDR1x) registers in the source address (SA) field for all transmitted frames. Note: Changes in this field take effect only on the start of a frame. If a write of this field occurs while a frame is being transmitted, only the subsequent frame can use the updated value, and the current frame does not. June 18, 2014 1471 Texas Instruments-Production Data Ethernet Controller Bit/Field Name Type Reset 27 TWOKPEN RW 0x0 Description IEEE 802.3as Support for 2K Packets When set, the MAC considers all frames, up to 2,000 bytes in length, as normal packets. This bit is only valid when the JFEN bit is set to 0. When JFEN is set, configuring TWOKPEN has no effect on Giant Frame status. Value Description 0 If the JFEN bit is clear, the MAC considers all received frames larger than 1,518 bytes (1,522 byes tagged) as Giant Frames. 1 Frames up to 2 KB are considered normal packets. If the JFEN bit is clear, the MAC considers all received frames larger that 2K bytes as Giant frames. 26 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 25 CST RW 0x0 CRC Stripping for Type Frames When set, the last four bytes (Frame Check Sequence FCS) of all frames of Ether type ((Length/Type field greater than or equal to 0x0600) are removed before forwarding the frame to the application. Value Description 0 No bytes are removed. 1 The last four bytes are removed before forwarding. 24 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 23 WDDIS RW 0x0 Watchdog Disable When this bit is set, the MAC disables the internal watchdog counter on the receiver. The MAC can receive frames of up to 16,384 bytes. When this bit is cleared, the MAC does not allow more than 2,048 bytes (10,240 if JFEN is set to 1) of the frame being received. The MAC cuts off any bytes received after 2,048 bytes. Value Description 22 JD RW 0x0 0 Watchdog counter enabled. 1 Watchdog counter disabled. Jabber Disable When this bit is set, the MAC disables the jabber counter on the transmitter. The MAC can transfer frames of up to 16,384 bytes. When this bit is clear, the MAC stops transmission if the application sends out more than 2,048 bytes of data (10,240 if JFEN is set to 1). Value Description 0 Jabber counter enabled. 1 Jabber counter disabled. 1472 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset Description 21 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 20 JFEN RW 0x0 Jumbo Frame Enable When this bit is set, the MAC allows jumbo frames of 9,018 bytes (9,022 bytes for VLAN tagged frames) without reporting a giant frame error in the receive frame status. Value Description 19:17 IFG RW 0x0 0 Jumbo frames create giant frame error. 1 Jumbo frames allowed without error. Inter-Frame Gap (IFG) These bits control the minimum IFG between frames during transmission. Value Description 0x0 96 bit times 0x1 88 bit times 0x2 80 bit times 0x3 72 bit times 0x4 64 bit times 0x5 56 bit times 0x6 48 bit times 0x7 40 bit times In half-duplex mode, the minimum IFG can be configured only for 64 bit times (IFG = 0x4). Lower values are not considered. 16 DISCRS RW 0x0 Disable Carrier Sense During Transmission When this bit is set, the MAC transmit module ignores carrier sense in half-duplex mode. Thus, errors are not generated when there is a loss of carrier or no carrier during transmission. When this bit is clear, the MAC transmitter generates errors because of carrier sense and can even abort the transmissions. Value Description 15 PS RO 1 0 Generate errors for carrier sense errors. 1 Ignore carrier sense errors. Port Select This bit indicates that a 10/100 Mbps interface is supported on this device. This is a read-only bit. 14 FES RW 0 Speed This bit indicates the speed of the interface. Value Description 0 10 Mbps 1 100 Mbps June 18, 2014 1473 Texas Instruments-Production Data Ethernet Controller Bit/Field Name Type Reset 13 DRO RW 0 Description Disable Receive Own When this bit is set, the MAC disables the reception of frames while transmitting in half-duplex mode. When this bit is clear, the MAC receives all packets that are given by the PHY while transmitting. Value Description 0 All packets are received by MAC. 1 Disable reception of frames. Note: 12 LOOPBM RW 0 This bit is not applicable if the MAC is operating in full-duplex mode. Loopback Mode When this bit is set, the MAC operates in the loopback mode at the MII. The MII Receive clock input, EN0RXCK, is required for the loopback to work properly, because the Transmit clock is not looped-back internally. Value Description 11 DUPM RW 0 0 MAC does not operate in loopback mode. 1 MAC operates in loopback mode. Duplex Mode When this bit is set, the MAC operates in the full-duplex mode where it can transmit and receive simultaneously. Value Description 10 IPC RW 0x0 0 MAC does not operate in full-duplex mode. 1 MAC operates in full-duplex mode. Checksum Offload Value Description 0 The checksum offload function in the receiver is disabled and the corresponding PCE and IP HCE status bits in the frame status are always cleared. 1 Checksum Offload Enable Setting this bit enables the IPv4 header checksum checking and IPv4 or IPv6 TCP, UDP, or ICMP payload checksum checking. 1474 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 9 DR RW 0x0 Description Disable Retry When this bit is set, the MAC attempts only one transmission. When a collision occurs on the MII interface, the MAC ignores the current frame transmission and reports a frame abort with excessive collision error in the transmit frame status. When this bit is cleared, the MAC attempts retries based on the settings of the BL field (Bits [6:5]). Note: This bit is only applicable in half-duplex mode. Value Description 0 MAC retries transmissions based on BL bit field. 1 Only one transmission is attempted by the MAC. 8 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7 ACS RW 0x0 Automatic Pad or CRC Stripping When this bit is set, the MAC strips the Pad or Frame Check Sequence (FCS) field on the incoming frames only if the value of the length field is less than 1,536 bytes. All received frames with length field greater than or equal to 1,536 bytes are passed to the application without stripping the Pad or FCS field. When this bit is cleared, the MAC passes all incoming frames, without modifying them, to the Host. Value Description 6:5 BL RW 0x0 0 All frames are passed to host unmodified. 1 MAC strips FCS field if value of length field is less than 1,536 bytes. Back-Off Limit The Back-Off limit determines the random integer number (r) of slot time delays (512 bit times for 10/100 Mbps) for which the MAC waits before rescheduling a transmission attempt during retries after a collision. The random integer r takes the value in the range 0 VIN+, VOUT = 0 As shown in Figure 22-2 on page 1655, the input source for VIN- is an external input, Cn-, where n is the analog comparator number. In addition to an external input, Cn+, input sources for VIN+ can be the C0+ or an internal reference, VIREF. Figure 22-2. Structure of Comparator Unit -ve input reference input output CINV 1 IntGen 2 TrigGen ACCTL ACSTAT trigger interrupt +ve input (alternate) 0 internal bus +ve input A comparator is configured through two status/control registers, Analog Comparator Control (ACCTL) and Analog Comparator Status (ACSTAT). The internal reference is configured through one control register, Analog Comparator Reference Voltage Control (ACREFCTL). Interrupt status and control are configured through three registers, Analog Comparator Masked Interrupt Status (ACMIS), Analog Comparator Raw Interrupt Status (ACRIS), and Analog Comparator Interrupt Enable (ACINTEN). Typically, the comparator output is used internally to generate an interrupt as controlled by the ISEN bit in the ACCTL register. The output may also be used to drive one of the external pins (Cno), or generate an analog-to-digital converter (ADC) trigger. June 18, 2014 1655 Texas Instruments-Production Data Analog Comparators Important: The ASRCP bits in the ACCTL register must be set before using the analog comparators. 22.3.1 Internal Reference Programming The structure of the internal reference is shown in Figure 22-3 on page 1656. The internal reference is controlled by a single configuration register (ACREFCTL). Figure 22-3. Comparator Internal Reference Structure N*R N*R 0xF 0xE 0x1 0x0 Decoder Note: internal reference VIREF In the figure above, N*R represents a multiple of the R value that produces the results specified in Table 22-2 on page 1656. The internal reference can be programmed in one of two modes (low range or high range) depending on the RNG bit in the ACREFCTL register. When RNG is clear, the internal reference is in high-range mode, and when RNG is set the internal reference is in low-range mode. In each range, the internal reference, VIREF, has 16 preprogrammed thresholds or step values. The threshold to be used to compare the external input voltage against is selected using the VREF field in the ACREFCTL register. In the high-range mode, the VIREF threshold voltages start at the ideal high-range starting voltage of VDDA/4.2 and increase in ideal constant voltage steps of VDDA/29.4. In the low-range mode, the VIREF threshold voltages start at 0 V and increase in ideal constant voltage steps of VDDA/22.12. The ideal VIREF step voltages for each mode and their dependence on the RNG and VREF fields are summarized in Table 22-2. Table 22-2. Internal Reference Voltage and ACREFCTL Field Values ACREFCTL Register EN Bit Value EN=0 RNG Bit Value RNG=X Output Reference Voltage Based on VREF Field Value 0 V (GND) for any value of VREF. It is recommended that RNG=1 and VREF=0 to minimize noise on the reference ground. 1656 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 22-2. Internal Reference Voltage and ACREFCTL Field Values (continued) ACREFCTL Register EN Bit Value RNG Bit Value RNG=0 Output Reference Voltage Based on VREF Field Value VIREF High Range: 16 voltage threshold values indexed by VREF = 0x0 .. 0xF Ideal starting voltage (VREF=0): VDDA / 4.2 Ideal step size: VDDA/ 29.4 Ideal VIREF threshold values: VIREF (VREF) = VDDA / 4.2 + VREF * (VDDA/ 29.4), for VREF = 0x0 .. 0xF For minimum and maximum VIREF threshold values, see Table 22-3 on page 1657. EN=1 RNG=1 VIREF Low Range: 16 voltage threshold values indexed by VREF = 0x0 .. 0xF Ideal starting voltage (VREF=0): 0 V Ideal step size: VDDA/ 22.12 Ideal VIREF threshold values: VIREF (VREF) = VREF * (VDDA/ 22.12), for VREF = 0x0 .. 0xF For minimum and maximum VIREF threshold values, see Table 22-4 on page 1658. Note that the values shown in Table 22-2 are the ideal values of the VIREF thresholds. These values actually vary between minimum and maximum values for each threshold step, depending on process and temperature. The minimum and maximum values for each step are given by: ■ VIREF(VREF) [Min] = Ideal VIREF(VREF) – (Ideal Step size – 2 mV) / 2 ■ VIREF(VREF) [Max] = Ideal VIREF(VREF) + (Ideal Step size – 2 mV) / 2 Examples of minimum and maximum VIREF values for VDDA = 3.3V for high and low ranges, are shown inTable 22-3 and Table 22-4. Note that these examples are only valid for VDDA = 3.3V; values scale up and down with VDDA. Table 22-3. Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 0 VREF Value VIREF Min Ideal VIREF VIREF Max Unit 0x0 0.731 0.786 0.841 V 0x1 0.843 0.898 0.953 V 0x2 0.955 1.010 1.065 V 0x3 1.067 1.122 1.178 V 0x4 1.180 1.235 1.290 V 0x5 1.292 1.347 1.402 V 0x6 1.404 1.459 1.514 V 0x7 1.516 1.571 1.627 V 0x8 1.629 1.684 1.739 V 0x9 1.741 1.796 1.851 V 0xA 1.853 1.908 1.963 V 0xB 1.965 2.020 2.076 V 0xC 2.078 2.133 2.188 V 0xD 2.190 2.245 2.300 V 0xE 2.302 2.357 2.412 V 0xF 2.414 2.469 2.525 V June 18, 2014 1657 Texas Instruments-Production Data Analog Comparators Table 22-4. Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 1 22.4 VREF Value VIREF Min Ideal VIREF VIREF Max Unit 0x0 0.000 0.000 0.074 V 0x1 0.076 0.149 0.223 V 0x2 0.225 0.298 0.372 V 0x3 0.374 0.448 0.521 V 0x4 0.523 0.597 0.670 V 0x5 0.672 0.746 0.820 V 0x6 0.822 0.895 0.969 V 0x7 0.971 1.044 1.118 V 0x8 1.120 1.193 1.267 V 0x9 1.269 1.343 1.416 V 0xA 1.418 1.492 1.565 V 0xB 1.567 1.641 1.715 V 0xC 1.717 1.790 1.864 V 0xD 1.866 1.939 2.013 V 0xE 2.015 2.089 2.162 V 0xF 2.164 2.238 2.311 V Initialization and Configuration The following example shows how to configure an analog comparator to read back its output value from an internal register. 1. Enable the analog comparator clock by writing a value of 0x0000.0001 to the RCGCACMP register in the System Control module (see page 397). 2. Enable the clock to the appropriate GPIO modules via the RCGCGPIO register (see page 382). To find out which GPIO ports to enable, refer to Table 26-5 on page 1808. 3. In the GPIO module, enable the GPIO port/pin associated with the input signals as GPIO inputs. To determine which GPIO to configure, see Table 26-4 on page 1797. 4. Configure the PMCn fields in the GPIOPCTL register to assign the analog comparator output signals to the appropriate pins (see page 787 and Table 26-5 on page 1808). 5. Configure the internal voltage reference to 1.65 V by writing the ACREFCTL register with the value 0x0000.030C. 6. Configure the comparator to use the internal voltage reference and to not invert the output by writing the ACCTLn register with the value of 0x0000.040C. 7. Delay for 10 µs. 8. Read the comparator output value by reading the ACSTATn register's OVAL value. Change the level of the comparator negative input signal C- to see the OVAL value change. 1658 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 22.5 Register Map Table 22-5 on page 1659 lists the comparator registers. The offset listed is a hexadecimal increment to the register's address, relative to the Analog Comparator base address of 0x4003.C000. Note that the analog comparator clock must be enabled before the registers can be programmed (see page 397). There must be a delay of 3 system clocks after the analog comparator module clock is enabled before any analog comparator module registers are accessed. Table 22-5. Analog Comparators Register Map Description See page 0x0000.0000 Analog Comparator Masked Interrupt Status 1660 RO 0x0000.0000 Analog Comparator Raw Interrupt Status 1661 ACINTEN RW 0x0000.0000 Analog Comparator Interrupt Enable 1662 0x010 ACREFCTL RW 0x0000.0000 Analog Comparator Reference Voltage Control 1663 0x020 ACSTAT0 RO 0x0000.0000 Analog Comparator Status 0 1664 0x024 ACCTL0 RW 0x0000.0000 Analog Comparator Control 0 1665 0x040 ACSTAT1 RO 0x0000.0000 Analog Comparator Status 1 1664 0x044 ACCTL1 RW 0x0000.0000 Analog Comparator Control 1 1665 0x060 ACSTAT2 RO 0x0000.0000 Analog Comparator Status 2 1664 0x064 ACCTL2 RW 0x0000.0000 Analog Comparator Control 2 1665 0xFC0 ACMPPP RO 0x0007.0007 Analog Comparator Peripheral Properties 1667 Offset Name Type Reset 0x000 ACMIS RW1C 0x004 ACRIS 0x008 22.6 Register Descriptions The remainder of this section lists and describes the Analog Comparator registers, in numerical order by address offset. June 18, 2014 1659 Texas Instruments-Production Data Analog Comparators Register 1: Analog Comparator Masked Interrupt Status (ACMIS), offset 0x000 This register provides a summary of the interrupt status (masked) of the comparators. Analog Comparator Masked Interrupt Status (ACMIS) Base 0x4003.C000 Offset 0x000 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 IN2 IN1 IN0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW1C 0 RW1C 0 RW1C 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:3 reserved RO 0x0000.000 2 IN2 RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Comparator 2 Masked Interrupt Status Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The IN2 bits in the ACRIS register and the ACINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the IN2 bit in the ACRIS register. 1 IN1 RW1C 0 Comparator 1 Masked Interrupt Status Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The IN1 bits in the ACRIS register and the ACINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the IN1 bit in the ACRIS register. 0 IN0 RW1C 0 Comparator 0 Masked Interrupt Status Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The IN0 bits in the ACRIS register and the ACINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the IN0 bit in the ACRIS register. 1660 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: Analog Comparator Raw Interrupt Status (ACRIS), offset 0x004 This register provides a summary of the interrupt status (raw) of the comparators. The bits in this register must be enabled to generate interrupts using the ACINTEN register. Analog Comparator Raw Interrupt Status (ACRIS) Base 0x4003.C000 Offset 0x004 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 IN2 IN1 IN0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:3 reserved RO 0x0000.000 2 IN2 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Comparator 2 Interrupt Status Value Description 0 An interrupt has not occurred. 1 Comparator 2 has generated an interrupt for an event as configured by the ISEN bit in the ACCTL2 register. This bit is cleared by writing a 1 to the IN2 bit in the ACMIS register. 1 IN1 RO 0 Comparator 1 Interrupt Status Value Description 0 An interrupt has not occurred. 1 Comparator 1 has generated an interruptfor an event as configured by the ISEN bit in the ACCTL1 register. This bit is cleared by writing a 1 to the IN1 bit in the ACMIS register. 0 IN0 RO 0 Comparator 0 Interrupt Status Value Description 0 An interrupt has not occurred. 1 Comparator 0 has generated an interrupt for an event as configured by the ISEN bit in the ACCTL0 register. This bit is cleared by writing a 1 to the IN0 bit in the ACMIS register. June 18, 2014 1661 Texas Instruments-Production Data Analog Comparators Register 3: Analog Comparator Interrupt Enable (ACINTEN), offset 0x008 This register provides the interrupt enable for the comparators. Analog Comparator Interrupt Enable (ACINTEN) Base 0x4003.C000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 IN2 IN1 IN0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset Description 31:3 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 IN2 RW 0 Comparator 2 Interrupt Enable Value Description 1 IN1 RW 0 0 A comparator 2 interrupt does not affect the interrupt status. 1 The raw interrupt signal comparator 2 is sent to the interrupt controller. Comparator 1 Interrupt Enable Value Description 0 IN0 RW 0 0 A comparator 1 interrupt does not affect the interrupt status. 1 The raw interrupt signal comparator 1 is sent to the interrupt controller. Comparator 0 Interrupt Enable Value Description 0 A comparator 0 interrupt does not affect the interrupt status. 1 The raw interrupt signal comparator 0 is sent to the interrupt controller. 1662 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 4: Analog Comparator Reference Voltage Control (ACREFCTL), offset 0x010 This register specifies whether the resistor ladder is powered on as well as the range and tap. Analog Comparator Reference Voltage Control (ACREFCTL) Base 0x4003.C000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 1 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 9 8 EN RNG RW 0 RW 0 Bit/Field Name Type Reset 31:10 reserved RO 0x0000.0 9 EN RW 0 reserved RO 0 RO 0 RO 0 VREF RO 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Resistor Ladder Enable Value Description 0 The resistor ladder is unpowered. 1 Powers on the resistor ladder. The resistor ladder is connected to VDDA. This bit is cleared at reset so that the internal reference consumes the least amount of power if it is not used. 8 RNG RW 0 Resistor Ladder Range Value Description 0 The ideal step size for the internal reference is VDDA / 29.4. 1 The ideal step size for the internal reference is VDDA / 22.12. 7:4 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3:0 VREF RW 0x0 Resistor Ladder Voltage Ref The VREF bit field specifies the resistor ladder tap that is passed through an analog multiplexer. The voltage corresponding to the tap position is the internal reference voltage available for comparison. See Table 22-2 on page 1656 for some output reference voltage examples. June 18, 2014 1663 Texas Instruments-Production Data Analog Comparators Register 5: Analog Comparator Status 0 (ACSTAT0), offset 0x020 Register 6: Analog Comparator Status 1 (ACSTAT1), offset 0x040 Register 7: Analog Comparator Status 2 (ACSTAT2), offset 0x060 These registers specify the current output value of the comparator. Analog Comparator Status n (ACSTATn) Base 0x4003.C000 Offset 0x020 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 OVAL reserved RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:2 reserved RO 0x0000.000 1 OVAL RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Comparator Output Value Value Description 0 VIN- > VIN+ 1 VIN- < VIN+ VIN - is the voltage on the Cn- pin. VIN+ is the voltage on the Cn+ pin, the C0+ pin, or the internal voltage reference (VIREF) as defined by the ASRCP bit in the ACCTL register. 0 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1664 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: Analog Comparator Control 0 (ACCTL0), offset 0x024 Register 9: Analog Comparator Control 1 (ACCTL1), offset 0x044 Register 10: Analog Comparator Control 2 (ACCTL2), offset 0x064 These registers configure the comparator's input and output. Analog Comparator Control n (ACCTLn) Base 0x4003.C000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 reserved TSLVAL CINV reserved RO 0 RW 0 RW 0 RO 0 reserved Type Reset reserved Type Reset TOEN RO 0 RO 0 ASRCP RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 11 TOEN RW 0 TSEN RW 0 ISLVAL RW 0 RW 0 ISEN RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Trigger Output Enable Value Description 10:9 ASRCP RW 0x0 0 ADC events are suppressed and not sent to the ADC. 1 ADC events are sent to the ADC. Analog Source Positive The ASRCP field specifies the source of input voltage to the VIN+ terminal of the comparator. The encodings for this field are as follows: Value Description 0x0 Pin value of Cn+ 0x1 Pin value of C0+ 0x2 Internal voltage reference (VIREF) 0x3 Reserved 8 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 7 TSLVAL RW 0 Trigger Sense Level Value Value Description 0 An ADC event is generated if the comparator output is Low. 1 An ADC event is generated if the comparator output is High. June 18, 2014 1665 Texas Instruments-Production Data Analog Comparators Bit/Field Name Type Reset 6:5 TSEN RW 0x0 Description Trigger Sense The TSEN field specifies the sense of the comparator output that generates an ADC event. The sense conditioning is as follows: Value Description 4 ISLVAL RW 0 0x0 Level sense, see TSLVAL 0x1 Falling edge 0x2 Rising edge 0x3 Either edge Interrupt Sense Level Value Value Description 3:2 ISEN RW 0x0 0 An interrupt is generated if the comparator output is Low. 1 An interrupt is generated if the comparator output is High. Interrupt Sense The ISEN field specifies the sense of the comparator output that generates an interrupt. The sense conditioning is as follows: Value Description 1 CINV RW 0 0x0 Level sense, see ISLVAL 0x1 Falling edge 0x2 Rising edge 0x3 Either edge Comparator Output Invert Value Description 0 reserved RO 0 0 The output of the comparator is unchanged. 1 The output of the comparator is inverted prior to being processed by hardware. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1666 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: Analog Comparator Peripheral Properties (ACMPPP), offset 0xFC0 The ACMPPP register provides information regarding the properties of the analog comparator module. Analog Comparator Peripheral Properties (ACMPPP) Base 0x4003.C000 Offset 0xFC0 Type RO, reset 0x0007.0007 31 30 29 28 27 26 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 25 24 23 22 21 20 19 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 5 4 3 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 18 17 16 C2O C1O C0O RO 1 RO 1 RO 1 2 1 0 CMP2 CMP1 CMP0 RO 1 RO 1 RO 1 Bit/Field Name Type Reset Description 31:19 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 18 C2O RO 0x1 Comparator Output 2 Present Value Description 17 C1O RO 0x1 0 Comparator output 2 is not present. 1 Comparator output 2 is present. Comparator Output 1 Present Value Description 16 C0O RO 0x1 0 Comparator output 1 is not present. 1 Comparator output 1 is present. Comparator Output 0 Present Value Description 0 Comparator output 0 is not present. 1 Comparator output 0 is present. 15:3 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 2 CMP2 RO 0x1 Comparator 2 Present Value Description 0 Comparator 2 is not present. 1 Comparator 2 is present. June 18, 2014 1667 Texas Instruments-Production Data Analog Comparators Bit/Field Name Type Reset 1 CMP1 RO 0x1 Description Comparator 1 Present Value Description 0 CMP0 RO 0x1 0 Comparator 1 is not present. 1 Comparator 1 is present. Comparator 0 Present Value Description 0 Comparator 0 is not present. 1 Comparator 0 is present. 1668 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 23 Pulse Width Modulator (PWM) Pulse width modulation (PWM) is a powerful technique for digitally encoding analog signal levels. High-resolution counters are used to generate a square wave, and the duty cycle of the square wave is modulated to encode an analog signal. Typical applications include switching power supplies and motor control. The TM4C1294NCPDT microcontroller contains one PWM module, with four PWM generator blocks and a control block, for a total of 8 PWM outputs. The control block determines the polarity of the PWM signals, and which signals are passed through to the pins. Each PWM generator block produces two PWM signals that share the same timer and frequency and can either be programmed with independent actions or as a single pair of complementary signals with dead-band delays inserted. The output signals, pwmA' and pwmB', of the PWM generation blocks are managed by the output control block before being passed to the device pins as MnPWM0 and MnPWM1 or MnPWM2 and MnPWM3, and so on. The TM4C1294NCPDT PWM module provides a great deal of flexibility and can generate simple PWM signals, such as those required by a simple charge pump as well as paired PWM signals with dead-band delays, such as those required by a half-H bridge driver. Three generator blocks can also generate the full six channels of gate controls required by a 3-phase inverter bridge. Each PWM generator block has the following features: ■ Four fault-condition handling inputs to quickly provide low-latency shutdown and prevent damage to the motor being controlled ■ One 16-bit counter – Runs in Down or Up/Down mode – Output frequency controlled by a 16-bit load value – Load value updates can be synchronized – Produces output signals at zero and load value ■ Two PWM comparators – Comparator value updates can be synchronized – Produces output signals on match ■ PWM signal generator – Output PWM signal is constructed based on actions taken as a result of the counter and PWM comparator output signals – Produces two independent PWM signals ■ Dead-band generator – Produces two PWM signals with programmable dead-band delays suitable for driving a half-H bridge – Can be bypassed, leaving input PWM signals unmodified June 18, 2014 1669 Texas Instruments-Production Data Pulse Width Modulator (PWM) ■ Can initiate an ADC sample sequence The control block determines the polarity of the PWM signals and which signals are passed through to the pins. The output of the PWM generation blocks are managed by the output control block before being passed to the device pins. The PWM control block has the following options: ■ PWM output enable of each PWM signal ■ Optional output inversion of each PWM signal (polarity control) ■ Optional fault handling for each PWM signal ■ Synchronization of timers in the PWM generator blocks ■ Synchronization of timer/comparator updates across the PWM generator blocks ■ Extended PWM synchronization of timer/comparator updates across the PWM generator blocks ■ Interrupt status summary of the PWM generator blocks ■ Extended PWM fault handling, with multiple fault signals, programmable polarities, and filtering ■ PWM generators can be operated independently or synchronized with other generators 23.1 Block Diagram Figure 23-1 on page 1671 provides the TM4C1294NCPDT PWM module diagram and Figure 23-2 on page 1671 provides a more detailed diagram of a TM4C1294NCPDT PWM generator. The TM4C1294NCPDT controller contains four generator blocks that generate eight independent PWM signals or four paired PWM signals with dead-band delays inserted. 1670 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 23-1. PWM Module Diagram PWM Clock Triggers / Faults System Clock pwm0A’ PWM Generator 0 Control and Status PWMCTL PWMSYNC PWMSTATUS PWMPP PWM 0 pwm0B’ PWM 1 pwm0fault pwm1A’ PWM Generator 1 PWM 2 pwm1B’ PWM PWM 3 pwm1fault Output Interrupt Control pwm2A’ Interrupts PWMINTEN PWMRIS PWMISC PWM Generator 2 PWM 4 Logic pwm2B’ PWM 5 pwm2fault Triggers pwm3A’ Output PWM Generator 3 PWMENABLE PWMINVERT PWMFAULT PWMFAULTVAL PWMENUPD PWM 6 pwm3B’ PWM 7 pwm3fault Figure 23-2. PWM Generator Block Diagram PWM Generator Block Interrupts / Triggers Control PWMnLOAD PWMnCOUNT PWMnFLTSRC0 PWMnFLTSRC1 PWMnMINFLTPER PWMnFLTSEN PWMnFLTSTAT0 PWMnFLTSTAT1 PWMnINTEN PWMnRIS PWMnISC PWMnCTL Timer Fault Condition Interrupt and Trigger Generator load dir pwmfault Signal Generator cmpA cmpB PWMnGENA PWMnGENB Dead-Band Generator pwmA pwmB PWM Clock Fault(s) zero Comparators PWMnCMPA PWMnCMPB Digital Trigger(s) PWMnDBCTL PWMnDBRISE PWMnDBFALL June 18, 2014 pwmA’ pwmB’ 1671 Texas Instruments-Production Data Pulse Width Modulator (PWM) 23.2 Signal Description The following table lists the external signals of the PWM module and describes the function of each. The PWM controller signals are alternate functions for some GPIO signals and default to be GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible GPIO pin placements for these PWM signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the PWM function. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the PWM signal to the specified GPIO port pin. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Table 23-1. PWM Signals (128TQFP) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description M0FAULT0 46 PF4 (6) I TTL Motion Control Module 0 PWM Fault 0. M0FAULT1 61 PK6 (6) I TTL Motion Control Module 0 PWM Fault 1. M0FAULT2 60 PK7 (6) I TTL Motion Control Module 0 PWM Fault 2. M0FAULT3 81 PL0 (6) I TTL Motion Control Module 0 PWM Fault 3. M0PWM0 42 PF0 (6) O TTL Motion Control Module 0 PWM 0. This signal is controlled by Module 0 PWM Generator 0. M0PWM1 43 PF1 (6) O TTL Motion Control Module 0 PWM 1. This signal is controlled by Module 0 PWM Generator 0. M0PWM2 44 PF2 (6) O TTL Motion Control Module 0 PWM 2. This signal is controlled by Module 0 PWM Generator 1. M0PWM3 45 PF3 (6) O TTL Motion Control Module 0 PWM 3. This signal is controlled by Module 0 PWM Generator 1. M0PWM4 49 PG0 (6) O TTL Motion Control Module 0 PWM 4. This signal is controlled by Module 0 PWM Generator 2. M0PWM5 50 PG1 (6) O TTL Motion Control Module 0 PWM 5. This signal is controlled by Module 0 PWM Generator 2. M0PWM6 63 PK4 (6) O TTL Motion Control Module 0 PWM 6. This signal is controlled by Module 0 PWM Generator 3. M0PWM7 62 PK5 (6) O TTL Motion Control Module 0 PWM 7. This signal is controlled by Module 0 PWM Generator 3. 23.3 Functional Description 23.3.1 Clock Configuration The PWM has two clock source options: ■ The System Clock ■ A predivided System Clock The clock source is selected by programming the USEPWM bit in the PWM Clock Configuration (PWMCC) register. The PWMDIV bitfield specifies the divisor of the System Clock that is used to create the PWM Clock. 23.3.2 PWM Timer The timer in each PWM generator runs in one of two modes: Count-Down mode or Count-Up/Down mode. In Count-Down mode, the timer counts from the load value to zero, goes back to the load 1672 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller value, and continues counting down. In Count-Up/Down mode, the timer counts from zero up to the load value, back down to zero, back up to the load value, and so on. Generally, Count-Down mode is used for generating left- or right-aligned PWM signals, while the Count-Up/Down mode is used for generating center-aligned PWM signals. The timers output three signals that are used in the PWM generation process: the direction signal (this is always Low in Count-Down mode, but alternates between Low and High in Count-Up/Down mode), a single-clock-cycle-width High pulse when the counter is zero, and a single-clock-cycle-width High pulse when the counter is equal to the load value. Note that in Count-Down mode, the zero pulse is immediately followed by the load pulse. In the figures in this chapter, these signals are labelled "dir," "zero," and "load." 23.3.3 PWM Comparators Each PWM generator has two comparators that monitor the value of the counter; when either comparator matches the counter, they output a single-clock-cycle-width High pulse, labeled "cmpA" and "cmpB" in the figures in this chapter. When in Count-Up/Down mode, these comparators match both when counting up and when counting down, and thus are qualified by the counter direction signal. These qualified pulses are used in the PWM generation process. If either comparator match value is greater than the counter load value, then that comparator never outputs a High pulse. Figure 23-3 on page 1674 shows the behavior of the counter and the relationship of these pulses when the counter is in Count-Down mode. Figure 23-4 on page 1674 shows the behavior of the counter and the relationship of these pulses when the counter is in Count-Up/Down mode. In these figures, the following definitions apply: ■ LOAD is the value in the PWMnLOAD register ■ COMPA is the value in the PWMnCMPA register ■ COMPB is the value in the PWMnCMPB register ■ 0 is the value zero ■ load is the internal signal that has a single-clock-cycle-width High pulse when the counter is equal to the load value ■ zero is the internal signal that has a single-clock-cycle-width High pulse when the counter is zero ■ cmpA is the internal signal that has a single-clock-cycle-width High pulse when the counter is equal to COMPA ■ cmpB is the internal signal that has a single-clock-cycle-width High pulse when the counter is equal to COMPB ■ dir is the internal signal that indicates the count direction June 18, 2014 1673 Texas Instruments-Production Data Pulse Width Modulator (PWM) Figure 23-3. PWM Count-Down Mode LOAD COMPA COMPB 0 load zero cmpA cmpB dir BDown ADown Figure 23-4. PWM Count-Up/Down Mode LOAD COMPA COMPB 0 load zero cmpA cmpB dir BUp AUp 23.3.4 BDown ADown PWM Signal Generator Each PWM generator takes the load, zero, cmpA, and cmpB pulses (qualified by the dir signal) and generates two internal PWM signals, pwmA and pwmB. In Count-Down mode, there are four events that can affect these signals: zero, load, match A down, and match B down. In Count-Up/Down mode, there are six events that can affect these signals: zero, load, match A down, match A up, match B down, and match B up. The match A or match B events are ignored when they coincide with the zero or load events. If the match A and match B events coincide, the first signal, pwmA, is generated based only on the match A event, and the second signal, pwmB, is generated based only on the match B event. For each event, the effect on each output PWM signal is programmable: it can be left alone (ignoring the event), it can be toggled, it can be driven Low, or it can be driven High. These actions can be used to generate a pair of PWM signals of various positions and duty cycles, which do or do not overlap. Figure 23-5 on page 1675 shows the use of Count-Up/Down mode to generate a pair of center-aligned, overlapped PWM signals that have different duty cycles. This figure shows the pwmA and pwmB signals before they have passed through the dead-band generator. 1674 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 23-5. PWM Generation Example In Count-Up/Down Mode LOAD COMPA COMPB 0 pwmA pwmB In this example, the first generator is set to drive High on match A up, drive Low on match A down, and ignore the other four events. The second generator is set to drive High on match B up, drive Low on match B down, and ignore the other four events. Changing the value of comparator A changes the duty cycle of the pwmA signal, and changing the value of comparator B changes the duty cycle of the pwmB signal. 23.3.5 Dead-Band Generator The pwmA and pwmB signals produced by each PWM generator are passed to the dead-band generator. If the dead-band generator is disabled, the PWM signals simply pass through to the pwmA' and pwmB' signals unmodified. If the dead-band generator is enabled, the pwmB signal is lost and two PWM signals are generated based on the pwmA signal. The first output PWM signal, pwmA' is the pwmA signal with the rising edge delayed by a programmable amount. The second output PWM signal, pwmB', is the inversion of the pwmA signal with a programmable delay added between the falling edge of the pwmA signal and the rising edge of the pwmB' signal. The resulting signals are a pair of active High signals where one is always High, except for a programmable amount of time at transitions where both are Low. These signals are therefore suitable for driving a half-H bridge, with the dead-band delays preventing shoot-through current from damaging the power electronics. Figure 23-6 on page 1675 shows the effect of the dead-band generator on the pwmA signal and the resulting pwmA' and pwmB' signals that are transmitted to the output control block. Figure 23-6. PWM Dead-Band Generator pwmA pwmA’ pwmB’ Rising Edge Delay 23.3.6 Falling Edge Delay Interrupt/ADC-Trigger Selector Each PWM generator also takes the same four (or six) counter events and uses them to generate an interrupt or an ADC trigger. Any of these events or a set of these events can be selected as a source for an interrupt; when any of the selected events occur, an interrupt is generated. Additionally, the same event, a different event, the same set of events, or a different set of events can be selected as a source for an ADC trigger; when any of these selected events occur, an ADC trigger pulse is generated. The selection of events allows the interrupt or ADC trigger to occur at a specific position June 18, 2014 1675 Texas Instruments-Production Data Pulse Width Modulator (PWM) within the pwmA or pwmB signal. Note that interrupts and ADC triggers are based on the raw events; delays in the PWM signal edges caused by the dead-band generator are not taken into account. 23.3.7 Synchronization Methods The PWM module provides four PWM generators, each providing two PWM outputs that may be used in a wide variety of applications. Generally speaking, the PWM is used in one of two categories of operation: ■ Unsynchronized. The PWM generator and its two output signals are used alone, independent of other PWM generators. ■ Synchronized. The PWM generator and its two outputs signals are used in conjunction with other PWM generators using a common, unified time base. If multiple PWM generators are configured with the same counter load value, synchronization can be used to guarantee that they also have the same count value (the PWM generators must be configured before they are synchronized). With this feature, more than two MnPWMn signals can be produced with a known relationship between the edges of those signals because the counters always have the same values. Other states in the module provide mechanisms to maintain the common time base and mutual synchronization. The counter in a PWM generator can be reset to zero by writing the PWM Time Base Sync (PWMSYNC) register and setting the SYNCn bit associated with the generator. Multiple PWM generators can be synchronized together by setting all necessary SYNCn bits in one access. For example, setting the SYNC0 and SYNC1 bits in the PWMSYNC register causes the counters in PWM generators 0 and 1 to reset together. Additional synchronization can occur between multiple PWM generators by updating register contents in one of the following three ways: ■ Immediately. The write value has immediate effect, and the hardware reacts immediately. ■ Locally Synchronized. The write value does not affect the logic until the counter reaches the value zero at the end of the PWM cycle. In this case, the effect of the write is deferred, providing a guaranteed defined behavior and preventing overly short or overly long output PWM pulses. ■ Globally Synchronized. The write value does not affect the logic until two sequential events have occurred: (1) the Update mode for the generator function is programmed for global synchronization in the PWMnCTL register, and (2) the counter reaches zero at the end of the PWM cycle. In this case, the effect of the write is deferred until the end of the PWM cycle following the end of all updates. This mode allows multiple items in multiple PWM generators to be updated simultaneously without odd effects during the update; everything runs from the old values until a point at which they all run from the new values. The Update mode of the load and comparator match values can be individually configured in each PWM generator block. It typically makes sense to use the synchronous update mechanism across PWM generator blocks when the timers in those blocks are synchronized, although this is not required in order for this mechanism to function properly. The following registers provide either local or global synchronization based on the state of various Update mode bits and fields in the PWMnCTL register (LOADUPD; CMPAUPD; CMPBUPD): ■ Generator Registers: PWMnLOAD, PWMnCMPA, and PWMnCMPB The following registers default to immediate update, but are provided with the optional functionality of synchronously updating rather than having all updates take immediate effect: 1676 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Module-Level Register: PWMENABLE (based on the state of the ENUPDn bits in the PWMENUPD register). ■ Generator Register: PWMnGENA, PWMnGENB, PWMnDBCTL, PWMnDBRISE, and PWMnDBFALL (based on the state of various Update mode bits and fields in the PWMnCTL register (GENAUPD; GENBUPD; DBCTLUPD; DBRISEUPD; DBFALLUPD)). All other registers are considered statically provisioned for the execution of an application or are used dynamically for purposes unrelated to maintaining synchronization and therefore do not need synchronous update functionality. 23.3.8 Fault Conditions A fault condition is one in which the controller must be signaled to stop normal PWM function and then set the MnPWMn signals to a safe state. Two basic situations cause fault conditions: ■ The microcontroller is stalled and cannot perform the necessary computation in the time required for motion control ■ An external error or event is detected The PWM generator can use the following inputs to generate a fault condition, including: ■ MnFAULTn pin assertion ■ A stall of the controller generated by the debugger ■ The trigger of an ADC digital comparator Fault conditions are calculated on a per-PWM generator basis. Each PWM generator configures the necessary conditions to indicate a fault condition exists. This method allows the development of applications with dependent and independent control. Four fault input pins (MnFAULTn) are available. These inputs may be used with circuits that generate an active High or active Low signal to indicate an error condition. A MnFAULTn pins may be individually programmed for the appropriate logic sense using the PWMnFLTSEN register. The PWM generator's mode control, including fault condition handling, is provided in the PWMnCTL register. This register determines whether the input or a combination of MnFAULTn input signals and/or digital comparator triggers (as configured by the PWMnFLTSRC0 and PWMnFLTSRC1 registers) is used to generate a fault condition. The PWMnCTL register also selects whether the fault condition is maintained as long as the external condition lasts or if it is latched until the fault condition until cleared by software. Finally, this register also enables a counter that may be used to extend the period of a fault condition for external events to assure that the duration is a minimum length. The minimum fault period count is specified in the PWMnMINFLTPER register. Note: When using an ADC digital comparator as a fault source, the LATCH and MINFLTPER bits in the PWMnCTL register should be set to 1 to ensure trigger assertions are captured. Status regarding the specific fault cause is provided in the PWMnFLTSTAT0 and PWMnFLTSTAT1 registers. Note that the fault status registers, PWMnFLTSTAT0 and PWMnFLTSTAT1, reflect the status of all fault sources, regardless of what fault sources are enabled for that particular generator. PWM generator fault conditions may be promoted to a controller interrupt using the PWMINTEN register. June 18, 2014 1677 Texas Instruments-Production Data Pulse Width Modulator (PWM) 23.3.9 Output Control Block The output control block takes care of the final conditioning of the pwmA' and pwmB' signals before they go to the pins as the MnPWMn signals. Via a single register, the PWM Output Enable (PWNENABLE) register, the set of PWM signals that are actually enabled to the pins can be modified. This function can be used, for example, to perform commutation of a brushless DC motor with a single register write (and without modifying the individual PWM generators, which are modified by the feedback control loop). In addition, the updating of the bits in the PWMENABLE register can be configured to be immediate or locally or globally synchronized to the next synchronous update using the PWM Enable Update (PWMENUPD) register. During fault conditions, the PWM output signals, MnPWMn, usually must be driven to safe values so that external equipment may be safely controlled. The PWMFAULT register specifies whether during a fault condition, the generated signal continues to be passed driven or to an encoding specified in the PWMFAULTVAL register. A final inversion can be applied to any of the MnPWMn signals, making them active Low instead of the default active High using the PWM Output Inversion (PWMINVERT). The inversion is applied even if a value has been enabled in the PWMFAULT register and specified in the PWMFAULTVAL register. In other words, if a bit is set in the PWMFAULT, PWMFAULTVAL, and PWMINVERT registers, the output on the MnPWMn signal is 0, not 1 as specified in the PWMFAULTVAL register. 23.4 Initialization and Configuration The following example shows how to initialize PWM Generator 0 with a 25-kHz frequency, a 25% duty cycle on the MnPWM0 pin, and a 75% duty cycle on the MnPWM1 pin. This example assumes the system clock is 20 MHz. 1. Enable the PWM clock by setting its corresponding bit in the RCGCPWM register in the System Control module (see page 398). 2. Enable the clock to the appropriate GPIO module via the RCGCGPIO register in the System Control module (see page 382). 3. In the GPIO module, enable the appropriate pins for their alternate function using the GPIOAFSEL register. To determine which GPIOs to configure, see Table 26-4 on page 1797. 4. Configure the PMCn fields in the GPIOPCTL register to assign the PWM signals to the appropriate pins (see page 787 and Table 26-5 on page 1808). 5. Configure the PWM Clock Configuration (PWMCC) register to use the PWM divide (USEPWMDIV) and set the divider (PWMDIV) to divide by 2 (0x0). 6. Configure the PWM generator for countdown mode with immediate updates to the parameters. ■ Write the PWM0CTL register with a value of 0x0000.0000. ■ Write the PWM0GENA register with a value of 0x0000.008C. ■ Write the PWM0GENB register with a value of 0x0000.080C. 7. Set the period. For a 25-KHz frequency, the period = 1/25,000, or 40 microseconds. The PWM clock source is 10 MHz; the system clock divided by 2. Thus there are 400 clock ticks per period. Use this value to set the PWM0LOAD register. In Count-Down mode, set the LOAD field in the PWM0LOAD register to the requested period minus one. 1678 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ Write the PWM0LOAD register with a value of 0x0000.018F. 8. Set the pulse width of the MnPWM0 pin for a 25% duty cycle. ■ Write the PWM0CMPA register with a value of 0x0000.012B. 9. Set the pulse width of the MnPWM1 pin for a 75% duty cycle. ■ Write the PWM0CMPB register with a value of 0x0000.0063. 10. Start the timers in PWM generator 0. ■ Write the PWM0CTL register with a value of 0x0000.0001. 11. Enable PWM outputs. ■ Write the PWMENABLE register with a value of 0x0000.0003. 23.5 Register Map Table 23-2 on page 1679 lists the PWM registers. The offset listed is a hexadecimal increment to the register's address, relative to the PWM module's base address: ■ PWM0: 0x4002.8000 Note that the PWM module clock must be enabled before the registers can be programmed. There must be a delay of 3 system clocks after the PWM module clock is enabled before any PWM module registers are accessed. Table 23-2. PWM Register Map Description See page 0x0000.0000 PWM Master Control 1683 RW 0x0000.0000 PWM Time Base Sync 1685 PWMENABLE RW 0x0000.0000 PWM Output Enable 1686 0x00C PWMINVERT RW 0x0000.0000 PWM Output Inversion 1688 0x010 PWMFAULT RW 0x0000.0000 PWM Output Fault 1690 0x014 PWMINTEN RW 0x0000.0000 PWM Interrupt Enable 1692 0x018 PWMRIS RO 0x0000.0000 PWM Raw Interrupt Status 1694 0x01C PWMISC RW1C 0x0000.0000 PWM Interrupt Status and Clear 1697 0x020 PWMSTATUS RO 0x0000.0000 PWM Status 1700 0x024 PWMFAULTVAL RW 0x0000.0000 PWM Fault Condition Value 1702 0x028 PWMENUPD RW 0x0000.0000 PWM Enable Update 1704 0x040 PWM0CTL RW 0x0000.0000 PWM0 Control 1708 0x044 PWM0INTEN RW 0x0000.0000 PWM0 Interrupt and Trigger Enable 1713 0x048 PWM0RIS RO 0x0000.0000 PWM0 Raw Interrupt Status 1716 Offset Name Type Reset 0x000 PWMCTL RW 0x004 PWMSYNC 0x008 June 18, 2014 1679 Texas Instruments-Production Data Pulse Width Modulator (PWM) Table 23-2. PWM Register Map (continued) Description See page 0x0000.0000 PWM0 Interrupt Status and Clear 1718 RW 0x0000.0000 PWM0 Load 1720 PWM0COUNT RO 0x0000.0000 PWM0 Counter 1721 0x058 PWM0CMPA RW 0x0000.0000 PWM0 Compare A 1722 0x05C PWM0CMPB RW 0x0000.0000 PWM0 Compare B 1723 0x060 PWM0GENA RW 0x0000.0000 PWM0 Generator A Control 1724 0x064 PWM0GENB RW 0x0000.0000 PWM0 Generator B Control 1727 0x068 PWM0DBCTL RW 0x0000.0000 PWM0 Dead-Band Control 1730 0x06C PWM0DBRISE RW 0x0000.0000 PWM0 Dead-Band Rising-Edge Delay 1731 0x070 PWM0DBFALL RW 0x0000.0000 PWM0 Dead-Band Falling-Edge-Delay 1732 0x074 PWM0FLTSRC0 RW 0x0000.0000 PWM0 Fault Source 0 1733 0x078 PWM0FLTSRC1 RW 0x0000.0000 PWM0 Fault Source 1 1735 0x07C PWM0MINFLTPER RW 0x0000.0000 PWM0 Minimum Fault Period 1738 0x080 PWM1CTL RW 0x0000.0000 PWM1 Control 1708 0x084 PWM1INTEN RW 0x0000.0000 PWM1 Interrupt and Trigger Enable 1713 0x088 PWM1RIS RO 0x0000.0000 PWM1 Raw Interrupt Status 1716 0x08C PWM1ISC RW1C 0x0000.0000 PWM1 Interrupt Status and Clear 1718 0x090 PWM1LOAD RW 0x0000.0000 PWM1 Load 1720 0x094 PWM1COUNT RO 0x0000.0000 PWM1 Counter 1721 0x098 PWM1CMPA RW 0x0000.0000 PWM1 Compare A 1722 0x09C PWM1CMPB RW 0x0000.0000 PWM1 Compare B 1723 0x0A0 PWM1GENA RW 0x0000.0000 PWM1 Generator A Control 1724 0x0A4 PWM1GENB RW 0x0000.0000 PWM1 Generator B Control 1727 0x0A8 PWM1DBCTL RW 0x0000.0000 PWM1 Dead-Band Control 1730 0x0AC PWM1DBRISE RW 0x0000.0000 PWM1 Dead-Band Rising-Edge Delay 1731 0x0B0 PWM1DBFALL RW 0x0000.0000 PWM1 Dead-Band Falling-Edge-Delay 1732 0x0B4 PWM1FLTSRC0 RW 0x0000.0000 PWM1 Fault Source 0 1733 0x0B8 PWM1FLTSRC1 RW 0x0000.0000 PWM1 Fault Source 1 1735 0x0BC PWM1MINFLTPER RW 0x0000.0000 PWM1 Minimum Fault Period 1738 0x0C0 PWM2CTL RW 0x0000.0000 PWM2 Control 1708 0x0C4 PWM2INTEN RW 0x0000.0000 PWM2 Interrupt and Trigger Enable 1713 0x0C8 PWM2RIS RO 0x0000.0000 PWM2 Raw Interrupt Status 1716 Offset Name Type Reset 0x04C PWM0ISC RW1C 0x050 PWM0LOAD 0x054 1680 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 23-2. PWM Register Map (continued) Description See page 0x0000.0000 PWM2 Interrupt Status and Clear 1718 RW 0x0000.0000 PWM2 Load 1720 PWM2COUNT RO 0x0000.0000 PWM2 Counter 1721 0x0D8 PWM2CMPA RW 0x0000.0000 PWM2 Compare A 1722 0x0DC PWM2CMPB RW 0x0000.0000 PWM2 Compare B 1723 0x0E0 PWM2GENA RW 0x0000.0000 PWM2 Generator A Control 1724 0x0E4 PWM2GENB RW 0x0000.0000 PWM2 Generator B Control 1727 0x0E8 PWM2DBCTL RW 0x0000.0000 PWM2 Dead-Band Control 1730 0x0EC PWM2DBRISE RW 0x0000.0000 PWM2 Dead-Band Rising-Edge Delay 1731 0x0F0 PWM2DBFALL RW 0x0000.0000 PWM2 Dead-Band Falling-Edge-Delay 1732 0x0F4 PWM2FLTSRC0 RW 0x0000.0000 PWM2 Fault Source 0 1733 0x0F8 PWM2FLTSRC1 RW 0x0000.0000 PWM2 Fault Source 1 1735 0x0FC PWM2MINFLTPER RW 0x0000.0000 PWM2 Minimum Fault Period 1738 0x100 PWM3CTL RW 0x0000.0000 PWM3 Control 1708 0x104 PWM3INTEN RW 0x0000.0000 PWM3 Interrupt and Trigger Enable 1713 0x108 PWM3RIS RO 0x0000.0000 PWM3 Raw Interrupt Status 1716 0x10C PWM3ISC RW1C 0x0000.0000 PWM3 Interrupt Status and Clear 1718 0x110 PWM3LOAD RW 0x0000.0000 PWM3 Load 1720 0x114 PWM3COUNT RO 0x0000.0000 PWM3 Counter 1721 0x118 PWM3CMPA RW 0x0000.0000 PWM3 Compare A 1722 0x11C PWM3CMPB RW 0x0000.0000 PWM3 Compare B 1723 0x120 PWM3GENA RW 0x0000.0000 PWM3 Generator A Control 1724 0x124 PWM3GENB RW 0x0000.0000 PWM3 Generator B Control 1727 0x128 PWM3DBCTL RW 0x0000.0000 PWM3 Dead-Band Control 1730 0x12C PWM3DBRISE RW 0x0000.0000 PWM3 Dead-Band Rising-Edge Delay 1731 0x130 PWM3DBFALL RW 0x0000.0000 PWM3 Dead-Band Falling-Edge-Delay 1732 0x134 PWM3FLTSRC0 RW 0x0000.0000 PWM3 Fault Source 0 1733 0x138 PWM3FLTSRC1 RW 0x0000.0000 PWM3 Fault Source 1 1735 0x13C PWM3MINFLTPER RW 0x0000.0000 PWM3 Minimum Fault Period 1738 0x800 PWM0FLTSEN RW 0x0000.0000 PWM0 Fault Pin Logic Sense 1739 0x804 PWM0FLTSTAT0 - 0x0000.0000 PWM0 Fault Status 0 1740 0x808 PWM0FLTSTAT1 - 0x0000.0000 PWM0 Fault Status 1 1742 Offset Name Type Reset 0x0CC PWM2ISC RW1C 0x0D0 PWM2LOAD 0x0D4 June 18, 2014 1681 Texas Instruments-Production Data Pulse Width Modulator (PWM) Table 23-2. PWM Register Map (continued) Description See page 0x0000.0000 PWM1 Fault Pin Logic Sense 1739 - 0x0000.0000 PWM1 Fault Status 0 1740 - 0x0000.0000 PWM1 Fault Status 1 1742 RW 0x0000.0000 PWM2 Fault Pin Logic Sense 1739 PWM2FLTSTAT0 - 0x0000.0000 PWM2 Fault Status 0 1740 0x908 PWM2FLTSTAT1 - 0x0000.0000 PWM2 Fault Status 1 1742 0x980 PWM3FLTSEN RW 0x0000.0000 PWM3 Fault Pin Logic Sense 1739 0x984 PWM3FLTSTAT0 - 0x0000.0000 PWM3 Fault Status 0 1740 0x988 PWM3FLTSTAT1 - 0x0000.0000 PWM3 Fault Status 1 1742 0xFC0 PWMPP RO 0x0000.0344 PWM Peripheral Properties 1745 0xFC8 PWMCC RW 0x0000.0005 PWM Clock Configuration 1747 Offset Name Type Reset 0x880 PWM1FLTSEN RW 0x884 PWM1FLTSTAT0 0x888 PWM1FLTSTAT1 0x900 PWM2FLTSEN 0x904 23.6 Register Descriptions The remainder of this section lists and describes the PWM registers, in numerical order by address offset. 1682 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: PWM Master Control (PWMCTL), offset 0x000 This register provides master control over the PWM generation blocks. PWM Master Control (PWMCTL) 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 GLOBALSYNC3 GLOBALSYNC2 GLOBALSYNC1 GLOBALSYNC0 PWM0 base: 0x4002.8000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 23 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:4 reserved RO 0x0000 3 GLOBALSYNC3 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Update PWM Generator 3 Value Description 0 No effect. 1 Any queued update to a load or comparator register in PWM generator 3 is applied the next time the corresponding counter becomes zero. This bit automatically clears when the updates have completed; it cannot be cleared by software. 2 GLOBALSYNC2 RW 0 Update PWM Generator 2 Value Description 0 No effect. 1 Any queued update to a load or comparator register in PWM generator 2 is applied the next time the corresponding counter becomes zero. This bit automatically clears when the updates have completed; it cannot be cleared by software. June 18, 2014 1683 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 1 GLOBALSYNC1 RW 0 Description Update PWM Generator 1 Value Description 0 No effect. 1 Any queued update to a load or comparator register in PWM generator 1 is applied the next time the corresponding counter becomes zero. This bit automatically clears when the updates have completed; it cannot be cleared by software. 0 GLOBALSYNC0 RW 0 Update PWM Generator 0 Value Description 0 No effect. 1 Any queued update to a load or comparator register in PWM generator 0 is applied the next time the corresponding counter becomes zero. This bit automatically clears when the updates have completed; it cannot be cleared by software. 1684 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 2: PWM Time Base Sync (PWMSYNC), offset 0x004 This register provides a method to perform synchronization of the counters in the PWM generation blocks. Setting a bit in this register causes the specified counter to reset back to 0; setting multiple bits resets multiple counters simultaneously. The bits auto-clear after the reset has occurred; reading them back as zero indicates that the synchronization has completed. PWM Time Base Sync (PWMSYNC) PWM0 base: 0x4002.8000 Offset 0x004 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 SYNC3 SYNC2 SYNC1 SYNC0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 SYNC3 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Reset Generator 3 Counter Value Description 2 SYNC2 RW 0 0 No effect. 1 Resets the PWM generator 3 counter. Reset Generator 2 Counter Value Description 1 SYNC1 RW 0 0 No effect. 1 Resets the PWM generator 2 counter. Reset Generator 1 Counter Value Description 0 SYNC0 RW 0 0 No effect. 1 Resets the PWM generator 1 counter. Reset Generator 0 Counter Value Description 0 No effect. 1 Resets the PWM generator 0 counter. June 18, 2014 1685 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 3: PWM Output Enable (PWMENABLE), offset 0x008 This register provides a master control of which generated pwmA' and pwmB' signals are output to the MnPWMn pins. By disabling a PWM output, the generation process can continue (for example, when the time bases are synchronized) without driving PWM signals to the pins. When bits in this register are set, the corresponding pwmA' or pwmB' signal is passed through to the output stage. When bits are clear, the pwmA' or pwmB' signal is replaced by a zero value which is also passed to the output stage. The PWMINVERT register controls the output stage, so if the corresponding bit is set in that register, the value seen on the MnPWMn signal is inverted from what is configured by the bits in this register. Updates to the bits in this register can be immediate or locally or globally synchronized to the next synchronous update as controlled by the ENUPDn fields in the PWMENUPD register. PWM Output Enable (PWMENABLE) PWM0 base: 0x4002.8000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 reserved Type Reset reserved Type Reset PWM7EN PWM6EN PWM5EN PWM4EN PWM3EN PWM2EN PWM1EN PWM0EN RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 PWM7EN RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. MnPWM7 Output Enable Value Description 6 PWM6EN RW 0 0 The MnPWM7 signal has a zero value. 1 The generated pwm3B' signal is passed to the MnPWM7 pin. MnPWM6 Output Enable Value Description 5 PWM5EN RW 0 0 The MnPWM6 signal has a zero value. 1 The generated pwm3A' signal is passed to the MnPWM6 pin. MnPWM5 Output Enable Value Description 0 The MnPWM5 signal has a zero value. 1 The generated pwm2B' signal is passed to the MnPWM5 pin. 1686 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 PWM4EN RW 0 Description MnPWM4 Output Enable Value Description 3 PWM3EN RW 0 0 The MnPWM4 signal has a zero value. 1 The generated pwm2A' signal is passed to the MnPWM4 pin. MnPWM3 Output Enable Value Description 2 PWM2EN RW 0 0 The MnPWM3 signal has a zero value. 1 The generated pwm1B' signal is passed to the MnPWM3 pin. MnPWM2 Output Enable Value Description 1 PWM1EN RW 0 0 The MnPWM2 signal has a zero value. 1 The generated pwm1A' signal is passed to the MnPWM2 pin. MnPWM1 Output Enable Value Description 0 PWM0EN RW 0 0 The MnPWM1 signal has a zero value. 1 The generated pwm0B' signal is passed to the MnPWM1 pin. MnPWM0 Output Enable Value Description 0 The MnPWM0 signal has a zero value. 1 The generated pwm0A' signal is passed to the MnPWM0 pin. June 18, 2014 1687 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 4: PWM Output Inversion (PWMINVERT), offset 0x00C This register provides a master control of the polarity of the MnPWMn signals on the device pins. The pwmA' and pwmB' signals generated by the PWM generator are active High; but can be made active Low via this register. Disabled PWM channels are also passed through the output inverter (if so configured) so that inactive signals can be High. In addition, if the PWMFAULT register enables a specific value to be placed on the MnPWMn signals during a fault condition, that value is inverted if the corresponding bit in this register is set. PWM Output Inversion (PWMINVERT) PWM0 base: 0x4002.8000 Offset 0x00C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 reserved Type Reset reserved Type Reset PWM7INV PWM6INV PWM5INV PWM4INV PWM3INV PWM2INV PWM1INV PWM0INV RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 PWM7INV RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Invert MnPWM7 Signal Value Description 6 PWM6INV RW 0 0 The MnPWM7 signal is not inverted. 1 The MnPWM7 signal is inverted. Invert MnPWM6 Signal Value Description 5 PWM5INV RW 0 0 The MnPWM6 signal is not inverted. 1 The MnPWM6 signal is inverted. Invert MnPWM5 Signal Value Description 4 PWM4INV RW 0 0 The MnPWM5 signal is not inverted. 1 The MnPWM5 signal is inverted. Invert MnPWM4 Signal Value Description 0 The MnPWM4 signal is not inverted. 1 The MnPWM4 signal is inverted. 1688 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 PWM3INV RW 0 Description Invert MnPWM3 Signal Value Description 2 PWM2INV RW 0 0 The MnPWM3 signal is not inverted. 1 The MnPWM3 signal is inverted. Invert MnPWM2 Signal Value Description 1 PWM1INV RW 0 0 The MnPWM2 signal is not inverted. 1 The MnPWM2 signal is inverted. Invert MnPWM1 Signal Value Description 0 PWM0INV RW 0 0 The MnPWM1 signal is not inverted. 1 The MnPWM1 signal is inverted. Invert MnPWM0 Signal Value Description 0 The MnPWM0 signal is not inverted. 1 The MnPWM0 signal is inverted. June 18, 2014 1689 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 5: PWM Output Fault (PWMFAULT), offset 0x010 This register controls the behavior of the MnPWMn outputs in the presence of fault conditions. Both the fault inputs (MnFAULTn pins and digital comparator outputs) and debug events are considered fault conditions. On a fault condition, each pwmA' or pwmB' signal can be passed through unmodified or driven to the value specified by the corresponding bit in the PWMFAULTVAL register. For outputs that are configured for pass-through, the debug event handling on the corresponding PWM generator also determines if the pwmA' or pwmB' signal continues to be generated. Fault condition control occurs before the output inverter, so PWM signals driven to a specified value on fault are inverted if the channel is configured for inversion (therefore, the pin is driven to the logical complement of the specified value on a fault condition). PWM Output Fault (PWMFAULT) PWM0 base: 0x4002.8000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 FAULT7 RW 0 RO 0 RO 0 7 6 5 4 3 2 1 0 FAULT7 FAULT6 FAULT5 FAULT4 FAULT3 FAULT2 FAULT1 FAULT0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. MnPWM7 Fault Value Description 6 FAULT6 RW 0 0 The generated pwm3B' signal is passed to the MnPWM7 pin. 1 The MnPWM7 output signal is driven to the value specified by the PWM7 bit in the PWMFAULTVAL register. MnPWM6 Fault Value Description 5 FAULT5 RW 0 0 The generated pwm3A' signal is passed to the MnPWM6 pin. 1 The MnPWM6 output signal is driven to the value specified by the PWM6 bit in the PWMFAULTVAL register. MnPWM5 Fault Value Description 0 The generated pwm2B' signal is passed to the MnPWM5 pin. 1 The MnPWM5 output signal is driven to the value specified by the PWM5 bit in the PWMFAULTVAL register. 1690 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 FAULT4 RW 0 Description MnPWM4 Fault Value Description 3 FAULT3 RW 0 0 The generated pwm2A' signal is passed to the MnPWM4 pin. 1 The MnPWM4 output signal is driven to the value specified by the PWM4 bit in the PWMFAULTVAL register. MnPWM3 Fault Value Description 2 FAULT2 RW 0 0 The generated pwm1B' signal is passed to the MnPWM3 pin. 1 The MnPWM3 output signal is driven to the value specified by the PWM3 bit in the PWMFAULTVAL register. MnPWM2 Fault Value Description 1 FAULT1 RW 0 0 The generated pwm1A' signal is passed to the MnPWM2 pin. 1 The MnPWM2 output signal is driven to the value specified by the PWM2 bit in the PWMFAULTVAL register. MnPWM1 Fault Value Description 0 FAULT0 RW 0 0 The generated pwm0B' signal is passed to the MnPWM1 pin. 1 The MnPWM1 output signal is driven to the value specified by the PWM1 bit in the PWMFAULTVAL register. MnPWM0 Fault Value Description 0 The generated pwm0A' signal is passed to the MnPWM0 pin. 1 The MnPWM0 output signal is driven to the value specified by the PWM0 bit in the PWMFAULTVAL register. June 18, 2014 1691 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 6: PWM Interrupt Enable (PWMINTEN), offset 0x014 This register controls the global interrupt generation capabilities of the PWM module. The events that can cause an interrupt are the fault input and the individual interrupts from the PWM generators. Note: The "n" in the INTFAULTn and INTPWMn bits in this register correspond to the PWM generators, not to the FAULTn signals. PWM Interrupt Enable (PWMINTEN) PWM0 base: 0x4002.8000 Offset 0x014 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 19 18 17 16 INTFAULT3 INTFAULT2 INTFAULT1 INTFAULT0 RW 0 RW 0 RW 0 RW 0 3 2 1 0 INTPWM3 INTPWM2 INTPWM1 INTPWM0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:20 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 INTFAULT3 RW 0 Interrupt Fault 3 Value Description 18 INTFAULT2 RW 0 0 The fault condition for PWM generator 3 is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the fault condition for PWM generator 3 is asserted. Interrupt Fault 2 Value Description 17 INTFAULT1 RW 0 0 The fault condition for PWM generator 2 is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the fault condition for PWM generator 2 is asserted. Interrupt Fault 1 Value Description 0 The fault condition for PWM generator 1 is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the fault condition for PWM generator 1 is asserted. 1692 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 16 INTFAULT0 RW 0 Description Interrupt Fault 0 Value Description 15:4 reserved RO 0x000 3 INTPWM3 RW 0 0 The fault condition for PWM generator 0 is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the fault condition for PWM generator 0 is asserted. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PWM3 Interrupt Enable Value Description 2 INTPWM2 RW 0 0 The PWM generator 3 interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PWM generator 3 block asserts an interrupt. PWM2 Interrupt Enable Value Description 1 INTPWM1 RW 0 0 The PWM generator 2 interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PWM generator 2 block asserts an interrupt. PWM1 Interrupt Enable Value Description 0 INTPWM0 RW 0 0 The PWM generator 1 interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PWM generator 1 block asserts an interrupt. PWM0 Interrupt Enable Value Description 0 The PWM generator 0 interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the PWM generator 0 block asserts an interrupt. June 18, 2014 1693 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 7: PWM Raw Interrupt Status (PWMRIS), offset 0x018 This register provides the current set of interrupt sources that are asserted, regardless of whether they are enabled to cause an interrupt to be asserted to the interrupt controller. The fault interrupt is asserted based on the fault condition source that is specified by the PWMnCTL, PWMnFLTSRC0 and PWMnFLTSRC1 registers. The fault interrupt is latched on detection and must be cleared through the PWM Interrupt Status and Clear (PWMISC) register. The actual value of the MnFAULTn signals can be observed using the PWMSTATUS register. The PWM generator interrupts simply reflect the status of the PWM generators and are cleared via the interrupt status register in the PWM generator blocks. If a bit is set, the event is active; if a bit is clear the event is not active. PWM Raw Interrupt Status (PWMRIS) PWM0 base: 0x4002.8000 Offset 0x018 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 19 18 17 16 INTFAULT3 INTFAULT2 INTFAULT1 INTFAULT0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 INTPWM3 INTPWM2 INTPWM1 INTPWM0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:20 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 INTFAULT3 RO 0 Interrupt Fault PWM 3 Value Description 0 The fault condition for PWM generator 3 has not been asserted. 1 The fault condition for PWM generator 3 is asserted. Note: 18 INTFAULT2 RO 0 If the LATCH bit is set in the PWM3CTL register, the INTFAULT3 bit in this register can be cleared by writing a 1 to the INTFAULT3 bit in the PWMISC register. If the LATCH bit is 0 in the PWM3CTL register, writing a 1 to the INTFAULT3 bit in the PWMISC register has no effect. Interrupt Fault PWM 2 Value Description 0 The fault condition for PWM generator 2 has not been asserted. 1 The fault condition for PWM generator 2 is asserted. Note: If the LATCH bit is set in the PWM2CTL register, the INTFAULT2 bit in this register can be cleared by writing a 1 to the INTFAULT2 bit in the PWMISC register. If the LATCH bit is 0 in the PWM2CTL register, writing a 1 to the INTFAULT2 bit in the PWMISC register has no effect. 1694 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 17 INTFAULT1 RO 0 Description Interrupt Fault PWM 1 Value Description 0 The fault condition for PWM generator 1 has not been asserted. 1 The fault condition for PWM generator 1 is asserted. Note: 16 INTFAULT0 RO 0 If the LATCH bit is set in the PWM1CTL register, the INTFAULT1 bit in this register can be cleared by writing a 1 to the INTFAULT1 bit in the PWMISC register. If the LATCH bit is 0 in the PWM1CTL register, writing a 1 to the INTFAULT1 bit in the PWMISC register has no effect. Interrupt Fault PWM 0 Value Description 0 The fault condition for PWM generator 0 has not been asserted. 1 The fault condition for PWM generator 0 is asserted. Note: 15:4 reserved RO 0x000 3 INTPWM3 RO 0 If the LATCH bit is set in the PWM0CTL register, the INTFAULT0 bit in this register can be cleared by writing a 1 to the INTFAULT0 bit in the PWMISC register. If the LATCH bit is 0 in the PWM0CTL register, writing a 1 to the INTFAULT0 bit in the PWMISC register has no effect. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PWM3 Interrupt Asserted Value Description 0 The PWM generator 3 block interrupt has not been asserted. 1 The PWM generator 3 block interrupt is asserted. The PWM3RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM3ISC register. 2 INTPWM2 RO 0 PWM2 Interrupt Asserted Value Description 0 The PWM generator 2 block interrupt has not been asserted. 1 The PWM generator 2 block interrupt is asserted. The PWM2RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM2ISC register. 1 INTPWM1 RO 0 PWM1 Interrupt Asserted Value Description 0 The PWM generator 1 block interrupt has not been asserted. 1 The PWM generator 1 block interrupt is asserted. The PWM1RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM1ISC register. June 18, 2014 1695 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 0 INTPWM0 RO 0 Description PWM0 Interrupt Asserted Value Description 0 The PWM generator 0 block interrupt has not been asserted. 1 The PWM generator 0 block interrupt is asserted. The PWM0RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM0ISC register. 1696 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 8: PWM Interrupt Status and Clear (PWMISC), offset 0x01C This register provides a summary of the interrupt status of the individual PWM generator blocks. If a fault interrupt is set, the corresponding MnFAULTn input has caused an interrupt. For the fault interrupt, a write of 1 to that bit position clears the latched interrupt status. If an block interrupt bit is set, the corresponding generator block is asserting an interrupt. The individual interrupt status registers, PWMnISC, in each block must be consulted to determine the reason for the interrupt and used to clear the interrupt. PWM Interrupt Status and Clear (PWMISC) PWM0 base: 0x4002.8000 Offset 0x01C Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 25 24 23 22 21 20 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 9 8 7 6 5 4 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset 19 18 17 16 INTFAULT3 INTFAULT2 INTFAULT1 INTFAULT0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 3 2 1 0 INTPWM3 INTPWM2 INTPWM1 INTPWM0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:20 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19 INTFAULT3 RW1C 0 FAULT3 Interrupt Asserted Value Description 0 The fault condition for PWM generator 3 has not been asserted or is not enabled. 1 An enabled interrupt for the fault condition for PWM generator 3 is asserted or is latched. Writing a 1 to this bit clears it and the INTFAULT3 bit in the PWMRIS register. 18 INTFAULT2 RW1C 0 FAULT2 Interrupt Asserted Value Description 0 The fault condition for PWM generator 2 has not been asserted or is not enabled. 1 An enabled interrupt for the fault condition for PWM generator 2 is asserted or is latched. Writing a 1 to this bit clears it and the INTFAULT2 bit in the PWMRIS register. June 18, 2014 1697 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 17 INTFAULT1 RW1C 0 Description FAULT1 Interrupt Asserted Value Description 0 The fault condition for PWM generator 1 has not been asserted or is not enabled. 1 An enabled interrupt for the fault condition for PWM generator 1 is asserted or is latched. Writing a 1 to this bit clears it and the INTFAULT1 bit in the PWMRIS register. 16 INTFAULT0 RW1C 0 FAULT0 Interrupt Asserted Value Description 0 The fault condition for PWM generator 0 has not been asserted or is not enabled. 1 An enabled interrupt for the fault condition for PWM generator 0 is asserted or is latched. Writing a 1 to this bit clears it and the INTFAULT0 bit in the PWMRIS register. 15:4 reserved RO 0x000 3 INTPWM3 RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PWM3 Interrupt Status Value Description 0 The PWM generator 3 block interrupt is not asserted or is not enabled. 1 An enabled interrupt for the PWM generator 3 block is asserted. The PWM3RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM3ISC register. 2 INTPWM2 RO 0 PWM2 Interrupt Status Value Description 0 The PWM generator 2 block interrupt is not asserted or is not enabled. 1 An enabled interrupt for the PWM generator 2 block is asserted. The PWM2RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM2ISC register. 1 INTPWM1 RO 0 PWM1 Interrupt Status Value Description 0 The PWM generator 1 block interrupt is not asserted or is not enabled. 1 An enabled interrupt for the PWM generator 1 block is asserted. The PWM1RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM1ISC register. 1698 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 INTPWM0 RO 0 Description PWM0 Interrupt Status Value Description 0 The PWM generator 0 block interrupt is not asserted or is not enabled. 1 An enabled interrupt for the PWM generator 0 block is asserted. The PWM0RIS register shows the source of this interrupt. This bit is cleared by writing a 1 to the corresponding bit in the PWM0ISC register. June 18, 2014 1699 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 9: PWM Status (PWMSTATUS), offset 0x020 This register provides the unlatched status of the PWM generator fault condition. PWM Status (PWMSTATUS) PWM0 base: 0x4002.8000 Offset 0x020 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 FAULT3 FAULT2 FAULT1 FAULT0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 FAULT3 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Generator 3 Fault Status Value Description 0 The fault condition for PWM generator 3 is not asserted. 1 The fault condition for PWM generator 3 is asserted. If the FLTSRC bit in the PWM3CTL register is clear, the input is the source of the fault condition, and is therefore asserted. 2 FAULT2 RO 0 Generator 2 Fault Status Value Description 0 The fault condition for PWM generator 2 is not asserted. 1 The fault condition for PWM generator 2 is asserted. If the FLTSRC bit in the PWM2CTL register is clear, the input is the source of the fault condition, and is therefore asserted. 1 FAULT1 RO 0 Generator 1 Fault Status Value Description 0 The fault condition for PWM generator 1 is not asserted. 1 The fault condition for PWM generator 1 is asserted. If the FLTSRC bit in the PWM1CTL register is clear, the input is the source of the fault condition, and is therefore asserted. 1700 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 0 FAULT0 RO 0 Description Generator 0 Fault Status Value Description 0 The fault condition for PWM generator 0 is not asserted. 1 The fault condition for PWM generator 0 is asserted. If the FLTSRC bit in the PWM0CTL register is clear, the input is the source of the fault condition, and is therefore asserted. June 18, 2014 1701 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 10: PWM Fault Condition Value (PWMFAULTVAL), offset 0x024 This register specifies the output value driven on the MnPWMn signals during a fault condition if enabled by the corresponding bit in the PWMFAULT register. Note that if the corresponding bit in the PWMINVERT register is set, the output value is driven to the logical NOT of the bit value in this register. PWM Fault Condition Value (PWMFAULTVAL) PWM0 base: 0x4002.8000 Offset 0x024 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 PWM7 PWM6 PWM5 PWM4 PWM3 PWM2 PWM1 PWM0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 PWM7 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. MnPWM7 Fault Value Value Description 6 PWM6 RW 0 0 The MnPWM7 output signal is driven Low during fault conditions if the FAULT7 bit in the PWMFAULT register is set. 1 The MnPWM7 output signal is driven High during fault conditions if the FAULT7 bit in the PWMFAULT register is set. MnPWM6 Fault Value Value Description 5 PWM5 RW 0 0 The MnPWM6 output signal is driven Low during fault conditions if the FAULT6 bit in the PWMFAULT register is set. 1 The MnPWM6 output signal is driven High during fault conditions if the FAULT6 bit in the PWMFAULT register is set. MnPWM5 Fault Value Value Description 0 The MnPWM5 output signal is driven Low during fault conditions if the FAULT5 bit in the PWMFAULT register is set. 1 The MnPWM5 output signal is driven High during fault conditions if the FAULT5 bit in the PWMFAULT register is set. 1702 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 PWM4 RW 0 Description MnPWM4 Fault Value Value Description 3 PWM3 RW 0 0 The MnPWM4 output signal is driven Low during fault conditions if the FAULT4 bit in the PWMFAULT register is set. 1 The MnPWM4 output signal is driven High during fault conditions if the FAULT4 bit in the PWMFAULT register is set. MnPWM3 Fault Value Value Description 2 PWM2 RW 0 0 The MnPWM3 output signal is driven Low during fault conditions if the FAULT3 bit in the PWMFAULT register is set. 1 The MnPWM3 output signal is driven High during fault conditions if the FAULT3 bit in the PWMFAULT register is set. MnPWM2 Fault Value Value Description 1 PWM1 RW 0 0 The MnPWM2 output signal is driven Low during fault conditions if the FAULT2 bit in the PWMFAULT register is set. 1 The MnPWM2 output signal is driven High during fault conditions if the FAULT2 bit in the PWMFAULT register is set. MnPWM1 Fault Value Value Description 0 PWM0 RW 0 0 The MnPWM1 output signal is driven Low during fault conditions if the FAULT1 bit in the PWMFAULT register is set. 1 The MnPWM1 output signal is driven High during fault conditions if the FAULT1 bit in the PWMFAULT register is set. MnPWM0 Fault Value Value Description 0 The MnPWM0 output signal is driven Low during fault conditions if the FAULT0 bit in the PWMFAULT register is set. 1 The MnPWM0 output signal is driven High during fault conditions if the FAULT0 bit in the PWMFAULT register is set. June 18, 2014 1703 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 11: PWM Enable Update (PWMENUPD), offset 0x028 This register specifies when updates to the PWMnEN bit in the PWMENABLE register are performed. The PWMnEN bit enables the pwmA' or pwmB' output to be passed to the microcontroller's pin. Updates can be immediate or locally or globally synchronized to the next synchronous update. PWM Enable Update (PWMENUPD) PWM0 base: 0x4002.8000 Offset 0x028 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset ENUPD7 Type Reset RW 0 RW 0 ENUPD6 RW 0 RW 0 ENUPD5 RW 0 RW 0 ENUPD4 RW 0 ENUPD3 ENUPD2 ENUPD1 ENUPD0 RW 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:14 ENUPD7 RW 0 MnPWM7 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM7EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM7EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM7EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. 1704 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 13:12 ENUPD6 RW 0 Description MnPWM6 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM6EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM6EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM6EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. 11:10 ENUPD5 RW 0 MnPWM5 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM5EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM5EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM5EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. 9:8 ENUPD4 RW 0 MnPWM4 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM4EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM4EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM4EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. June 18, 2014 1705 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 7:6 ENUPD3 RW 0 Description MnPWM3 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM3EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM3EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM3EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. 5:4 ENUPD2 RW 0 MnPWM2 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM2EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM2EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM2EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. 3:2 ENUPD1 RW 0 MnPWM1 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM1EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM1EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM1EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. 1706 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 1:0 ENUPD0 RW 0 Description MnPWM0 Enable Update Mode Value Description 0x0 Immediate Writes to the PWM0EN bit in the PWMENABLE register are used by the PWM generator immediately. 0x1 Reserved 0x2 Locally Synchronized Writes to the PWM0EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0. 0x3 Globally Synchronized Writes to the PWM0EN bit in the PWMENABLE register are used by the PWM generator the next time the counter is 0 after a synchronous update has been requested through the PWM Master Control (PWMCTL) register. June 18, 2014 1707 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 12: PWM0 Control (PWM0CTL), offset 0x040 Register 13: PWM1 Control (PWM1CTL), offset 0x080 Register 14: PWM2 Control (PWM2CTL), offset 0x0C0 Register 15: PWM3 Control (PWM3CTL), offset 0x100 These registers configure the PWM signal generation blocks (PWM0CTL controls the PWM generator 0 block, and so on). The Register Update mode, Debug mode, Counting mode, and Block Enable mode are all controlled via these registers. The blocks produce the PWM signals, which can be either two independent PWM signals (from the same counter), or a paired set of PWM signals with dead-band delays added. The PWM0 block produces the MnPWM0 and MnPWM1 outputs, the PWM1 block produces the MnPWM2 and MnPWM3 outputs, the PWM2 block produces the MnPWM4 and MnPWM5 outputs, and the PWM3 block produces the MnPWM6 and MnPWM7 outputs. PWMn Control (PWMnCTL) PWM0 base: 0x4002.8000 Offset 0x040 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 DBFALLUPD Type Reset RW 0 RW 0 DBRISEUPD RW 0 RW 0 DBCTLUPD RW 0 RW 0 GENBUPD RW 0 GENAUPD RW 0 RW 0 18 17 16 LATCH MINFLTPER FLTSRC RW 0 RW 0 RO 0 RO 0 RO 0 RW 0 5 4 3 2 CMPBUPD CMPAUPD LOADUPD DEBUG RW 0 RW 0 RW 0 RW 0 RW 0 1 0 MODE ENABLE RW 0 RW 0 Bit/Field Name Type Reset Description 31:19 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 18 LATCH RW 0 Latch Fault Input Value Description 0 Fault Condition Not Latched A fault condition is in effect for as long as the generating source is asserting. 1 Fault Condition Latched A fault condition is set as the result of the assertion of the faulting source and is held (latched) while the PWMISC INTFAULTn bit is set. Clearing the INTFAULTn bit clears the fault condition. Note: When using an ADC digital comparator as a fault source, the LATCH and MINFLTPER bits in the PWMnCTL register should be set to 1 to ensure trigger assertions are captured. 1708 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 17 MINFLTPER RW 0 Description Minimum Fault Period This bit specifies that the PWM generator enables a one-shot counter to provide a minimum fault condition period. The timer begins counting on the rising edge of the fault condition to extend the condition for a minimum duration of the count value. The timer ignores the state of the fault condition while counting. The minimum fault delay is in effect only when the MINFLTPER bit is set. If a detected fault is in the process of being extended when the MINFLTPER bit is cleared, the fault condition extension is aborted. The delay time is specified by the PWMnMINFLTPER register MFP field value. The effect of this is to pulse stretch the fault condition input. The delay value is defined by the PWM clock period. Because the fault input is not synchronized to the PWM clock, the period of the time is PWMClock * (MFP value + 1) or PWMClock * (MFP value + 2). The delay function makes sense only if the fault source is unlatched. A latched fault source makes the fault condition appear asserted until cleared by software and negates the utility of the extend feature. It applies to all fault condition sources as specified in the FLTSRC field. Value Description 0 The FAULT input deassertion is unaffected. 1 The PWMnMINFLTPER one-shot counter is active and extends the period of the fault condition to a minimum period. Note: 16 FLTSRC RW 0 When using an ADC digital comparator as a fault source, the LATCH and MINFLTPER bits in the PWMnCTL register should be set to 1 to ensure trigger assertions are captured. Fault Condition Source Value Description 15:14 DBFALLUPD RW 0x0 0 The Fault condition is determined by the Fault0 input. 1 The Fault condition is determined by the configuration of the PWMnFLTSRC0 and PWMnFLTSRC1 registers. PWMnDBFALL Update Mode Value Description 0x0 Immediate The PWMnDBFALL register value is immediately updated on a write. 0x1 Reserved 0x2 Locally Synchronized Updates to the register are reflected to the generator the next time the counter is 0. 0x3 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. June 18, 2014 1709 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 13:12 DBRISEUPD RW 0x0 Description PWMnDBRISE Update Mode Value Description 0x0 Immediate The PWMnDBRISE register value is immediately updated on a write. 0x1 Reserved 0x2 Locally Synchronized Updates to the register are reflected to the generator the next time the counter is 0. 0x3 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. 11:10 DBCTLUPD RW 0x0 PWMnDBCTL Update Mode Value Description 0x0 Immediate The PWMnDBCTL register value is immediately updated on a write. 0x1 Reserved 0x2 Locally Synchronized Updates to the register are reflected to the generator the next time the counter is 0. 0x3 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. 9:8 GENBUPD RW 0x0 PWMnGENB Update Mode Value Description 0x0 Immediate The PWMnGENB register value is immediately updated on a write. 0x1 Reserved 0x2 Locally Synchronized Updates to the register are reflected to the generator the next time the counter is 0. 0x3 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. 1710 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 7:6 GENAUPD RW 0x0 Description PWMnGENA Update Mode Value Description 0x0 Immediate The PWMnGENA register value is immediately updated on a write. 0x1 Reserved 0x2 Locally Synchronized Updates to the register are reflected to the generator the next time the counter is 0. 0x3 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. 5 CMPBUPD RW 0 Comparator B Update Mode Value Description 0 Locally Synchronized Updates to the PWMnCMPB register are reflected to the generator the next time the counter is 0. 1 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. 4 CMPAUPD RW 0 Comparator A Update Mode Value Description 0 Locally Synchronized Updates to the PWMnCMPA register are reflected to the generator the next time the counter is 0. 1 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. 3 LOADUPD RW 0 Load Register Update Mode Value Description 0 Locally Synchronized Updates to the PWMnLOAD register are reflected to the generator the next time the counter is 0. 1 Globally Synchronized Updates to the register are delayed until the next time the counter is 0 after a synchronous update has been requested through the PWMCTL register. June 18, 2014 1711 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 2 DEBUG RW 0 Description Debug Mode Value Description 1 MODE RW 0 0 The counter stops running when it next reaches 0 and continues running again when no longer in Debug mode. 1 The counter always runs when in Debug mode. Counter Mode Value Description 0 ENABLE RW 0 0 The counter counts down from the load value to 0 and then wraps back to the load value (Count-Down mode). 1 The counter counts up from 0 to the load value, back down to 0, and then repeats (Count-Up/Down mode). PWM Block Enable Note: Disabling the PWM by clearing the ENABLE bit does not clear the COUNT field of the PWMnCOUNT register. Before re-enabling the PWM (ENABLE = 0x1), the COUNT field should be cleared by resetting the PWM registers through the SRPWM register in the System Control Module. Value Description 0 The entire PWM generation block is disabled and not clocked. 1 The PWM generation block is enabled and produces PWM signals. 1712 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 16: PWM0 Interrupt and Trigger Enable (PWM0INTEN), offset 0x044 Register 17: PWM1 Interrupt and Trigger Enable (PWM1INTEN), offset 0x084 Register 18: PWM2 Interrupt and Trigger Enable (PWM2INTEN), offset 0x0C4 Register 19: PWM3 Interrupt and Trigger Enable (PWM3INTEN), offset 0x104 These registers control the interrupt and ADC trigger generation capabilities of the PWM generators (PWM0INTEN controls the PWM generator 0 block, and so on). The events that can cause an interrupt,or an ADC trigger are: ■ The counter being equal to the load register ■ The counter being equal to zero ■ The counter being equal to the PWMnCMPA register while counting up ■ The counter being equal to the PWMnCMPA register while counting down ■ The counter being equal to the PWMnCMPB register while counting up ■ The counter being equal to the PWMnCMPB register while counting down Any combination of these events can generate either an interrupt or an ADC trigger, though no determination can be made as to the actual event that caused an ADC trigger if more than one is specified. The PWMnRIS register provides information about which events have caused raw interrupts. PWMn Interrupt and Trigger Enable (PWMnINTEN) PWM0 base: 0x4002.8000 Offset 0x044 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 15 14 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 13 12 11 10 9 TRCMPBD TRCMPBU TRCMPAD TRCMPAU TRCNTLOAD RW 0 RW 0 RW 0 RW 0 RW 0 RO 0 RO 0 RO 0 8 7 6 TRCNTZERO RW 0 reserved RO 0 INTCMPBD INTCMPBU INTCMPAD INTCMPAU INTCNTLOAD INTCNTZERO RO 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:14 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 13 TRCMPBD RW 0 Trigger for Counter=PWMnCMPB Down Value Description 0 No ADC trigger is output. 1 An ADC trigger pulse is output when the counter matches the value in the PWMnCMPB register value while counting down. June 18, 2014 1713 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 12 TRCMPBU RW 0 Description Trigger for Counter=PWMnCMPB Up Value Description 11 TRCMPAD RW 0 0 No ADC trigger is output. 1 An ADC trigger pulse is output when the counter matches the value in the PWMnCMPB register value while counting up. Trigger for Counter=PWMnCMPA Down Value Description 10 TRCMPAU RW 0 0 No ADC trigger is output. 1 An ADC trigger pulse is output when the counter matches the value in the PWMnCMPA register value while counting down. Trigger for Counter=PWMnCMPA Up Value Description 9 TRCNTLOAD RW 0 0 No ADC trigger is output. 1 An ADC trigger pulse is output when the counter matches the value in the PWMnCMPA register value while counting up. Trigger for Counter=PWMnLOAD Value Description 8 TRCNTZERO RW 0 0 No ADC trigger is output. 1 An ADC trigger pulse is output when the counter matches the PWMnLOAD register. Trigger for Counter=0 Value Description 7:6 reserved RO 0x0 5 INTCMPBD RW 0 0 No ADC trigger is output. 1 An ADC trigger pulse is output when the counter is 0. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Interrupt for Counter=PWMnCMPB Down Value Description 0 No interrupt. 1 A raw interrupt occurs when the counter matches the value in the PWMnCMPB register value while counting down. 1714 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 4 INTCMPBU RW 0 Description Interrupt for Counter=PWMnCMPB Up Value Description 3 INTCMPAD RW 0 0 No interrupt. 1 A raw interrupt occurs when the counter matches the value in the PWMnCMPB register value while counting up. Interrupt for Counter=PWMnCMPA Down Value Description 2 INTCMPAU RW 0 0 No interrupt. 1 A raw interrupt occurs when the counter matches the value in the PWMnCMPA register value while counting down. Interrupt for Counter=PWMnCMPA Up Value Description 1 INTCNTLOAD RW 0 0 No interrupt. 1 A raw interrupt occurs when the counter matches the value in the PWMnCMPA register value while counting up. Interrupt for Counter=PWMnLOAD Value Description 0 INTCNTZERO RW 0 0 No interrupt. 1 A raw interrupt occurs when the counter matches the value in the PWMnLOAD register value. Interrupt for Counter=0 Value Description 0 No interrupt. 1 A raw interrupt occurs when the counter is zero. June 18, 2014 1715 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 20: PWM0 Raw Interrupt Status (PWM0RIS), offset 0x048 Register 21: PWM1 Raw Interrupt Status (PWM1RIS), offset 0x088 Register 22: PWM2 Raw Interrupt Status (PWM2RIS), offset 0x0C8 Register 23: PWM3 Raw Interrupt Status (PWM3RIS), offset 0x108 These registers provide the current set of interrupt sources that are asserted, regardless of whether they cause an interrupt to be asserted to the controller (PWM0RIS controls the PWM generator 0 block, and so on). If a bit is set, the event has occurred; if a bit is clear, the event has not occurred. Bits in this register are cleared by writing a 1 to the corresponding bit in the PWMnISC register. PWMn Raw Interrupt Status (PWMnRIS) PWM0 base: 0x4002.8000 Offset 0x048 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 INTCMPBD INTCMPBU INTCMPAD INTCMPAU INTCNTLOAD INTCNTZERO RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5 INTCMPBD RO 0 Comparator B Down Interrupt Status Value Description 0 An interrupt has not occurred. 1 The counter has matched the value in the PWMnCMPB register while counting down. This bit is cleared by writing a 1 to the INTCMPBD bit in the PWMnISC register. 4 INTCMPBU RO 0 Comparator B Up Interrupt Status Value Description 0 An interrupt has not occurred. 1 The counter has matched the value in the PWMnCMPB register while counting up. This bit is cleared by writing a 1 to the INTCMPBU bit in the PWMnISC register. 1716 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 INTCMPAD RO 0 Description Comparator A Down Interrupt Status Value Description 0 An interrupt has not occurred. 1 The counter has matched the value in the PWMnCMPA register while counting down. This bit is cleared by writing a 1 to the INTCMPAD bit in the PWMnISC register. 2 INTCMPAU RO 0 Comparator A Up Interrupt Status Value Description 0 An interrupt has not occurred. 1 The counter has matched the value in the PWMnCMPA register while counting up. This bit is cleared by writing a 1 to the INTCMPAU bit in the PWMnISC register. 1 INTCNTLOAD RO 0 Counter=Load Interrupt Status Value Description 0 An interrupt has not occurred. 1 The counter has matched the value in the PWMnLOAD register. This bit is cleared by writing a 1 to the INTCNTLOAD bit in the PWMnISC register. 0 INTCNTZERO RO 0 Counter=0 Interrupt Status Value Description 0 An interrupt has not occurred. 1 The counter has matched zero. This bit is cleared by writing a 1 to the INTCNTZERO bit in the PWMnISC register. June 18, 2014 1717 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 24: PWM0 Interrupt Status and Clear (PWM0ISC), offset 0x04C Register 25: PWM1 Interrupt Status and Clear (PWM1ISC), offset 0x08C Register 26: PWM2 Interrupt Status and Clear (PWM2ISC), offset 0x0CC Register 27: PWM3 Interrupt Status and Clear (PWM3ISC), offset 0x10C These registers provide the current set of interrupt sources that are asserted to the interrupt controller (PWM0ISC controls the PWM generator 0 block, and so on). A bit is set if the event has occurred and is enabled in the PWMnINTEN register; if a bit is clear, the event has not occurred or is not enabled. These are RW1C registers; writing a 1 to a bit position clears the corresponding interrupt reason. Note: The interrupt status can only be cleared one PWM Clock cycle after the interrupt occurs. The larger the PWM Clock Divider (PWMDIV) value in PWMCC register, the longer the system delay is to clear the interrupt. PWMn Interrupt Status and Clear (PWMnISC) PWM0 base: 0x4002.8000 Offset 0x04C Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 INTCMPBD INTCMPBU INTCMPAD INTCMPAU INTCNTLOAD INTCNTZERO RO 0 RO 0 RO 0 RO 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 Bit/Field Name Type Reset Description 31:6 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 5 INTCMPBD RW1C 0 Comparator B Down Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTCMPBD bits in the PWMnRIS and PWMnINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTCMPBD bit in the PWMnRIS register. 4 INTCMPBU RW1C 0 Comparator B Up Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTCMPBU bits in the PWMnRIS and PWMnINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTCMPBU bit in the PWMnRIS register. 1718 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 INTCMPAD RW1C 0 Description Comparator A Down Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTCMPAD bits in the PWMnRIS and PWMnINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTCMPAD bit in the PWMnRIS register. 2 INTCMPAU RW1C 0 Comparator A Up Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTCMPAU bits in the PWMnRIS and PWMnINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTCMPAU bit in the PWMnRIS register. 1 INTCNTLOAD RW1C 0 Counter=Load Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTCNTLOAD bits in the PWMnRIS and PWMnINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTCNTLOAD bit in the PWMnRIS register. 0 INTCNTZERO RW1C 0 Counter=0 Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTCNTZERO bits in the PWMnRIS and PWMnINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTCNTZERO bit in the PWMnRIS register. June 18, 2014 1719 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 28: PWM0 Load (PWM0LOAD), offset 0x050 Register 29: PWM1 Load (PWM1LOAD), offset 0x090 Register 30: PWM2 Load (PWM2LOAD), offset 0x0D0 Register 31: PWM3 Load (PWM3LOAD), offset 0x110 These registers contain the load value for the PWM counter (PWM0LOAD controls the PWM generator 0 block, and so on). Based on the counter mode configured by the MODE bit in the PWMnCTL register, this value is either loaded into the counter after it reaches zero or is the limit of up-counting after which the counter decrements back to zero. When this value matches the counter, a pulse is output which can be configured to drive the generation of the pwmA and/or pwmB signal (via the PWMnGENA/PWMnGENB register) or drive an interruptor ADC trigger (via the PWMnINTEN register). If the Load Value Update mode is locally synchronized (based on the LOADUPD field encoding in the PWMnCTL register), the 16-bit LOAD value is used the next time the counter reaches zero. If the update mode is globally synchronized, it is used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is re-written before the actual update occurs, the previous value is never used and is lost. PWMn Load (PWMnLOAD) PWM0 base: 0x4002.8000 Offset 0x050 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 LOAD Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 LOAD RW 0x0000 Counter Load Value The counter load value. 1720 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 32: PWM0 Counter (PWM0COUNT), offset 0x054 Register 33: PWM1 Counter (PWM1COUNT), offset 0x094 Register 34: PWM2 Counter (PWM2COUNT), offset 0x0D4 Register 35: PWM3 Counter (PWM3COUNT), offset 0x114 These registers contain the current value of the PWM counter (PWM0COUNT is the value of the PWM generator 0 block, and so on). When this value matches zero or the value in the PWMnLOAD, PWMnCMPA, or PWMnCMPB registers, a pulse is output which can be configured to drive the generation of a PWM signal or drive an interrupt or ADC trigger. Note: Disabling the PWM by clearing the ENABLE bit does not clear the COUNT field of the PWMnCOUNT register. Before re-enabling the PWM (ENABLE = 0x1), the COUNT field should be cleared by resetting the PWM registers through the SRPWM register in the System Control Module. PWMn Counter (PWMnCOUNT) PWM0 base: 0x4002.8000 Offset 0x054 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 COUNT Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 COUNT RO 0x0000 Counter Value The current value of the counter. June 18, 2014 1721 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 36: PWM0 Compare A (PWM0CMPA), offset 0x058 Register 37: PWM1 Compare A (PWM1CMPA), offset 0x098 Register 38: PWM2 Compare A (PWM2CMPA), offset 0x0D8 Register 39: PWM3 Compare A (PWM3CMPA), offset 0x118 These registers contain a value to be compared against the counter (PWM0CMPA controls the PWM generator 0 block, and so on). When this value matches the counter, a pulse is output which can be configured to drive the generation of the pwmA and pwmB signals (via the PWMnGENA and PWMnGENB registers) or drive an interrupt or ADC trigger (via the PWMnINTEN register). If the value of this register is greater than the PWMnLOAD register (see page 1720), then no pulse is ever output. If the comparator A update mode is locally synchronized (based on the CMPAUPD bit in the PWMnCTL register), the 16-bit COMPA value is used the next time the counter reaches zero. If the update mode is globally synchronized, it is used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is rewritten before the actual update occurs, the previous value is never used and is lost. PWMn Compare A (PWMnCMPA) PWM0 base: 0x4002.8000 Offset 0x058 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 COMPA Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x00 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 COMPA RW 0x00 Comparator A Value The value to be compared against the counter. 1722 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 40: PWM0 Compare B (PWM0CMPB), offset 0x05C Register 41: PWM1 Compare B (PWM1CMPB), offset 0x09C Register 42: PWM2 Compare B (PWM2CMPB), offset 0x0DC Register 43: PWM3 Compare B (PWM3CMPB), offset 0x11C These registers contain a value to be compared against the counter (PWM0CMPB controls the PWM generator 0 block, and so on). When this value matches the counter, a pulse is output which can be configured to drive the generation of the pwmA and pwmB signals (via the PWMnGENA and PWMnGENB registers) or drive an interrupt or ADC trigger (via the PWMnINTEN register). If the value of this register is greater than the PWMnLOAD register, no pulse is ever output. If the comparator B update mode is locally synchronized (based on the CMPBUPD bit in the PWMnCTL register), the 16-bit COMPB value is used the next time the counter reaches zero. If the update mode is globally synchronized, it is used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is rewritten before the actual update occurs, the previous value is never used and is lost. PWMn Compare B (PWMnCMPB) PWM0 base: 0x4002.8000 Offset 0x05C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 COMPB Type Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 COMPB RW 0x0000 Comparator B Value The value to be compared against the counter. June 18, 2014 1723 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 44: PWM0 Generator A Control (PWM0GENA), offset 0x060 Register 45: PWM1 Generator A Control (PWM1GENA), offset 0x0A0 Register 46: PWM2 Generator A Control (PWM2GENA), offset 0x0E0 Register 47: PWM3 Generator A Control (PWM3GENA), offset 0x120 These registers control the generation of the pwmA signal based on the load and zero output pulses from the counter, as well as the compare A and compare B pulses from the comparators (PWM0GENA controls the PWM generator 0 block, and so on). When the counter is running in Count-Down mode, only four of these events occur; when running in Count-Up/Down mode, all six occur. These events provide great flexibility in the positioning and duty cycle of the resulting PWM signal. The PWM0GENA register controls generation of the pwm0A signal; PWM1GENA, the pwm1A signal; PWM2GENA, the pwm2A signal; and PWM3GENA, the pwm3A signal. If a zero or load event coincides with a compare A or compare B event, the zero or load action is taken and the compare A or compare B action is ignored. If a compare A event coincides with a compare B event, the compare A action is taken and the compare B action is ignored. If the Generator A update mode is immediate (based on the GENAUPD field encoding in the PWMnCTL register), the ACTCMPBD, ACTCMPBU, ACTCMPAD, ACTCMPAU, ACTLOAD, and ACTZERO values are used immediately. If the update mode is locally synchronized, these values are used the next time the counter reaches zero. If the update mode is globally synchronized, these values are used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is rewritten before the actual update occurs, the previous value is never used and is lost. PWMn Generator A Control (PWMnGENA) PWM0 base: 0x4002.8000 Offset 0x060 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 reserved Type Reset RO 0 RO 0 ACTCMPBD RO 0 RO 0 RW 0 RW 0 RO 0 RO 0 9 8 ACTCMPBU RW 0 Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 RW 0 ACTCMPAD RW 0 RW 0 ACTCMPAU RW 0 RW 0 ACTLOAD RW 0 RW 0 ACTZERO RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1724 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 11:10 ACTCMPBD RW 0x0 Description Action for Comparator B Down This field specifies the action to be taken when the counter matches comparator B while counting down. Value Description 9:8 ACTCMPBU RW 0x0 0x0 Do nothing. 0x1 Invert pwmA. 0x2 Drive pwmA Low. 0x3 Drive pwmA High. Action for Comparator B Up This field specifies the action to be taken when the counter matches comparator B while counting up. This action can only occur when the MODE bit in the PWMnCTL register is set. Value Description 7:6 ACTCMPAD RW 0x0 0x0 Do nothing. 0x1 Invert pwmA. 0x2 Drive pwmA Low. 0x3 Drive pwmA High. Action for Comparator A Down This field specifies the action to be taken when the counter matches comparator A while counting down. Value Description 5:4 ACTCMPAU RW 0x0 0x0 Do nothing. 0x1 Invert pwmA. 0x2 Drive pwmA Low. 0x3 Drive pwmA High. Action for Comparator A Up This field specifies the action to be taken when the counter matches comparator A while counting up. This action can only occur when the MODE bit in the PWMnCTL register is set. Value Description 0x0 Do nothing. 0x1 Invert pwmA. 0x2 Drive pwmA Low. 0x3 Drive pwmA High. June 18, 2014 1725 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 3:2 ACTLOAD RW 0x0 Description Action for Counter=LOAD This field specifies the action to be taken when the counter matches the value in the PWMnLOAD register. Value Description 1:0 ACTZERO RW 0x0 0x0 Do nothing. 0x1 Invert pwmA. 0x2 Drive pwmA Low. 0x3 Drive pwmA High. Action for Counter=0 This field specifies the action to be taken when the counter is zero. Value Description 0x0 Do nothing. 0x1 Invert pwmA. 0x2 Drive pwmA Low. 0x3 Drive pwmA High. 1726 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 48: PWM0 Generator B Control (PWM0GENB), offset 0x064 Register 49: PWM1 Generator B Control (PWM1GENB), offset 0x0A4 Register 50: PWM2 Generator B Control (PWM2GENB), offset 0x0E4 Register 51: PWM3 Generator B Control (PWM3GENB), offset 0x124 These registers control the generation of the pwmB signal based on the load and zero output pulses from the counter, as well as the compare A and compare B pulses from the comparators (PWM0GENB controls the PWM generator 0 block, and so on). When the counter is running in Count-Down mode, only four of these events occur; when running in Count-Up/Down mode, all six occur. These events provide great flexibility in the positioning and duty cycle of the resulting PWM signal. The PWM0GENB register controls generation of the pwm0B signal; PWM1GENB, the pwm1B signal; PWM2GENB, the pwm2B signal; and PWM3GENB, the pwm3B signal. If a zero or load event coincides with a compare A or compare B event, the zero or load action is taken and the compare A or compare B action is ignored. If a compare A event coincides with a compare B event, the compare B action is taken and the compare A action is ignored. If the Generator B update mode is immediate (based on the GENBUPD field encoding in the PWMnCTL register), the ACTCMPBD, ACTCMPBU, ACTCMPAD, ACTCMPAU, ACTLOAD, and ACTZERO values are used immediately. If the update mode is locally synchronized, these values are used the next time the counter reaches zero. If the update mode is globally synchronized, these values are used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is rewritten before the actual update occurs, the previous value is never used and is lost. PWMn Generator B Control (PWMnGENB), offset 0x064 PWM0 base: 0x4002.8000 Offset 0x064 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 reserved Type Reset RO 0 RO 0 ACTCMPBD RO 0 RO 0 RW 0 RW 0 RO 0 RO 0 9 8 ACTCMPBU RW 0 Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 RW 0 ACTCMPAD RW 0 RW 0 ACTCMPAU RW 0 RW 0 ACTLOAD RW 0 RW 0 ACTZERO RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. June 18, 2014 1727 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 11:10 ACTCMPBD RW 0x0 Description Action for Comparator B Down This field specifies the action to be taken when the counter matches comparator B while counting down. Value Description 9:8 ACTCMPBU RW 0x0 0x0 Do nothing. 0x1 Invert pwmB. 0x2 Drive pwmB Low. 0x3 Drive pwmB High. Action for Comparator B Up This field specifies the action to be taken when the counter matches comparator B while counting up. This action can only occur when the MODE bit in the PWMnCTL register is set. Value Description 7:6 ACTCMPAD RW 0x0 0x0 Do nothing. 0x1 Invert pwmB. 0x2 Drive pwmB Low. 0x3 Drive pwmB High. Action for Comparator A Down This field specifies the action to be taken when the counter matches comparator A while counting down. Value Description 5:4 ACTCMPAU RW 0x0 0x0 Do nothing. 0x1 Invert pwmB. 0x2 Drive pwmB Low. 0x3 Drive pwmB High. Action for Comparator A Up This field specifies the action to be taken when the counter matches comparator A while counting up. This action can only occur when the MODE bit in the PWMnCTL register is set. Value Description 0x0 Do nothing. 0x1 Invert pwmB. 0x2 Drive pwmB Low. 0x3 Drive pwmB High. 1728 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3:2 ACTLOAD RW 0x0 Description Action for Counter=LOAD This field specifies the action to be taken when the counter matches the load value. Value Description 1:0 ACTZERO RW 0x0 0x0 Do nothing. 0x1 Invert pwmB. 0x2 Drive pwmB Low. 0x3 Drive pwmB High. Action for Counter=0 This field specifies the action to be taken when the counter is 0. Value Description 0x0 Do nothing. 0x1 Invert pwmB. 0x2 Drive pwmB Low. 0x3 Drive pwmB High. June 18, 2014 1729 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 52: PWM0 Dead-Band Control (PWM0DBCTL), offset 0x068 Register 53: PWM1 Dead-Band Control (PWM1DBCTL), offset 0x0A8 Register 54: PWM2 Dead-Band Control (PWM2DBCTL), offset 0x0E8 Register 55: PWM3 Dead-Band Control (PWM3DBCTL), offset 0x128 The PWMnDBCTL register controls the dead-band generator, which produces the MnPWMn signals based on the pwmA and pwmB signals. When disabled, the pwmA signal passes through to the pwmA' signal and the pwmB signal passes through to the pwmB' signal. When dead-band control is enabled, the pwmB signal is ignored, the pwmA' signal is generated by delaying the rising edge(s) of the pwmA signal by the value in the PWMnDBRISE register (see page 1731), and the pwmB' signal is generated by inverting the pwmA signal and delaying the falling edge(s) of the pwmA signal by the value in the PWMnDBFALL register (see page 1732). The Output Control block outputs the pwm0A' signal on the MnPWM0 signal and the pwm0B' signal on the MnPWM1 signal. In a similar manner, MnPWM2 and MnPWM3 are produced from the pwm1A' and pwm1B' signals, MnPWM4 and MnPWM5 are produced from the pwm2A' and pwm2B' signals, and MnPWM6 and MnPWM7 are produced from the pwm3A' and pwm3B' signals. If the Dead-Band Control mode is immediate (based on the DBCTLUPD field encoding in the PWMnCTL register), the ENABLE bit value is used immediately. If the update mode is locally synchronized, this value is used the next time the counter reaches zero. If the update mode is globally synchronized, this value is used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is rewritten before the actual update occurs, the previous value is never used and is lost. PWMn Dead-Band Control (PWMnDBCTL) PWM0 base: 0x4002.8000 Offset 0x068 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:1 reserved RO 0x0000.000 0 ENABLE RW 0 RO 0 ENABLE RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Dead-Band Generator Enable Value Description 0 The pwmA and pwmB signals pass through to the pwmA' and pwmB' signals unmodified. 1 The dead-band generator modifies the pwmA signal by inserting dead bands into the pwmA' and pwmB' signals. 1730 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 56: PWM0 Dead-Band Rising-Edge Delay (PWM0DBRISE), offset 0x06C Register 57: PWM1 Dead-Band Rising-Edge Delay (PWM1DBRISE), offset 0x0AC Register 58: PWM2 Dead-Band Rising-Edge Delay (PWM2DBRISE), offset 0x0EC Register 59: PWM3 Dead-Band Rising-Edge Delay (PWM3DBRISE), offset 0x12C The PWMnDBRISE register contains the number of clock cycles to delay the rising edge of the pwmA signal when generating the pwmA' signal. If the dead-band generator is disabled through the PWMnDBCTL register, this register is ignored. If the value of this register is larger than the width of a High pulse on the pwmA signal, the rising-edge delay consumes the entire High time of the signal, resulting in no High time on the output. Care must be taken to ensure that the pwmA High time always exceeds the rising-edge delay. If the Dead-Band Rising-Edge Delay mode is immediate (based on the DBRISEUPD field encoding in the PWMnCTL register), the 12-bit RISEDELAY value is used immediately. If the update mode is locally synchronized, this value is used the next time the counter reaches zero. If the update mode is globally synchronized, this value is used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is rewritten before the actual update occurs, the previous value is never used and is lost. PWMn Dead-Band Rising-Edge Delay (PWMnDBRISE) PWM0 base: 0x4002.8000 Offset 0x06C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 reserved Type Reset RO 0 RO 0 RISEDELAY RO 0 RO 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 11:0 RISEDELAY RW 0x000 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Dead-Band Rise Delay The number of clock cycles to delay the rising edge of pwmA' after the rising edge of pwmA. June 18, 2014 1731 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 60: PWM0 Dead-Band Falling-Edge-Delay (PWM0DBFALL), offset 0x070 Register 61: PWM1 Dead-Band Falling-Edge-Delay (PWM1DBFALL), offset 0x0B0 Register 62: PWM2 Dead-Band Falling-Edge-Delay (PWM2DBFALL), offset 0x0F0 Register 63: PWM3 Dead-Band Falling-Edge-Delay (PWM3DBFALL), offset 0x130 The PWMnDBFALL register contains the number of clock cycles to delay the rising edge of the pwmB' signal from the falling edge of the pwmA signal. If the dead-band generator is disabled through the PWMnDBCTL register, this register is ignored. If the value of this register is larger than the width of a Low pulse on the pwmA signal, the falling-edge delay consumes the entire Low time of the signal, resulting in no Low time on the output. Care must be taken to ensure that the pwmA Low time always exceeds the falling-edge delay. If the Dead-Band Falling-Edge-Delay mode is immediate (based on the DBFALLUP field encoding in the PWMnCTL register), the 12-bit FALLDELAY value is used immediately. If the update mode is locally synchronized, this value is used the next time the counter reaches zero. If the update mode is globally synchronized, this value is used the next time the counter reaches zero after a synchronous update has been requested through the PWM Master Control (PWMCTL) register (see page 1683). If this register is rewritten before the actual update occurs, the previous value is never used and is lost. PWMn Dead-Band Falling-Edge-Delay (PWMnDBFALL) PWM0 base: 0x4002.8000 Offset 0x070 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 reserved Type Reset RO 0 RO 0 FALLDELAY RO 0 RO 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset 31:12 reserved RO 0x0000.0 11:0 FALLDELAY RW 0x000 RW 0 RW 0 RW 0 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Dead-Band Fall Delay The number of clock cycles to delay the falling edge of pwmB' from the rising edge of pwmA. 1732 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 64: PWM0 Fault Source 0 (PWM0FLTSRC0), offset 0x074 Register 65: PWM1 Fault Source 0 (PWM1FLTSRC0), offset 0x0B4 Register 66: PWM2 Fault Source 0 (PWM2FLTSRC0), offset 0x0F4 Register 67: PWM3 Fault Source 0 (PWM3FLTSRC0), offset 0x134 This register specifies which fault pin inputs are used to generate a fault condition. Each bit in the following register indicates whether the corresponding fault pin is included in the fault condition. All enabled fault pins are ORed together to form the PWMnFLTSRC0 portion of the fault condition. The PWMnFLTSRC0 fault condition is then ORed with the PWMnFLTSRC1 fault condition to generate the final fault condition for the PWM generator. If the FLTSRC bit in the PWMnCTL register (see page 1708) is clear, only the Fault0 signal affects the fault condition generated. Otherwise, sources defined in PWMnFLTSRC0 and PWMnFLTSRC1 affect the fault condition generated. PWMn Fault Source 0 (PWMnFLTSRC0) PWM0 base: 0x4002.8000 Offset 0x074 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 FAULT3 FAULT2 FAULT1 FAULT0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 FAULT3 RW 0 Fault3 Input Value Description 0 The Fault3 signal is suppressed and cannot generate a fault condition. 1 The Fault3 signal value is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. June 18, 2014 1733 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 2 FAULT2 RW 0 Description Fault2 Input Value Description 0 The Fault2 signal is suppressed and cannot generate a fault condition. 1 The Fault2 signal value is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: 1 FAULT1 RW 0 The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. Fault1 Input Value Description 0 The Fault1 signal is suppressed and cannot generate a fault condition. 1 The Fault1 signal value is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: 0 FAULT0 RW 0 The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. Fault0 Input Value Description 0 The Fault0 signal is suppressed and cannot generate a fault condition. 1 The Fault0 signal value is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. 1734 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 68: PWM0 Fault Source 1 (PWM0FLTSRC1), offset 0x078 Register 69: PWM1 Fault Source 1 (PWM1FLTSRC1), offset 0x0B8 Register 70: PWM2 Fault Source 1 (PWM2FLTSRC1), offset 0x0F8 Register 71: PWM3 Fault Source 1 (PWM3FLTSRC1), offset 0x138 This register specifies which digital comparator triggers from the ADC are used to generate a fault condition. Each bit in the following register indicates whether the corresponding digital comparator trigger is included in the fault condition. All enabled digital comparator triggers are ORed together to form the PWMnFLTSRC1 portion of the fault condition. The PWMnFLTSRC1 fault condition is then ORed with the PWMnFLTSRC0 fault condition to generate the final fault condition for the PWM generator. If the FLTSRC bit in the PWMnCTL register (see page 1708) is clear, only the PWM Fault0 pin affects the fault condition generated. Otherwise, sources defined in PWMnFLTSRC0 and PWMnFLTSRC1 affect the fault condition generated. PWMn Fault Source 1 (PWMnFLTSRC1) PWM0 base: 0x4002.8000 Offset 0x078 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 DCMP7 RW 0 RO 0 7 6 5 4 3 2 1 0 DCMP7 DCMP6 DCMP5 DCMP4 DCMP3 DCMP2 DCMP1 DCMP0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Digital Comparator 7 Value Description 0 The trigger from digital comparator 7 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 7 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. June 18, 2014 1735 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 6 DCMP6 RW 0 Description Digital Comparator 6 Value Description 0 The trigger from digital comparator 6 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 6 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: 5 DCMP5 RW 0 The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. Digital Comparator 5 Value Description 0 The trigger from digital comparator 5 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 5 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: 4 DCMP4 RW 0 The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. Digital Comparator 4 Value Description 0 The trigger from digital comparator 4 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 4 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: 3 DCMP3 RW 0 The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. Digital Comparator 3 Value Description 0 The trigger from digital comparator 3 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 3 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. 1736 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 2 DCMP2 RW 0 Description Digital Comparator 2 Value Description 0 The trigger from digital comparator 2 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 2 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: 1 DCMP1 RW 0 The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. Digital Comparator 1 Value Description 0 The trigger from digital comparator 1 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 1 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: 0 DCMP0 RW 0 The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. Digital Comparator 0 Value Description 0 The trigger from digital comparator 0 is suppressed and cannot generate a fault condition. 1 The trigger from digital comparator 0 is ORed with all other fault condition generation inputs (Faultn signals and digital comparators). Note: The FLTSRC bit in the PWMnCTL register must be set for this bit to affect fault condition generation. June 18, 2014 1737 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 72: PWM0 Minimum Fault Period (PWM0MINFLTPER), offset 0x07C Register 73: PWM1 Minimum Fault Period (PWM1MINFLTPER), offset 0x0BC Register 74: PWM2 Minimum Fault Period (PWM2MINFLTPER), offset 0x0FC Register 75: PWM3 Minimum Fault Period (PWM3MINFLTPER), offset 0x13C If the MINFLTPER bit in the PWMnCTL register is set, this register specifies the 16-bit time-extension value to be used in extending the fault condition. The value is loaded into a 16-bit down counter, and the counter value is used to extend the fault condition. The fault condition is released in the clock immediately after the counter value reaches 0. The fault condition is asynchronous to the PWM clock; and the delay value is the product of the PWM clock period and the (MFP field value + 1) or (MFP field value + 2) depending on when the fault condition asserts with respect to the PWM clock. The counter decrements at the PWM clock rate, without pause or condition. PWMn Minimum Fault Period (PWMnMINFLTPER) PWM0 base: 0x4002.8000 Offset 0x07C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset MFP Type Reset Bit/Field Name Type Reset Description 31:16 reserved RO 0x0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 15:0 MFP RW 0x0000 Minimum Fault Period The number of PWM clocks by which a fault condition is extended when the delay is enabled by PWMnCTL MINFLTPER. 1738 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 76: PWM0 Fault Pin Logic Sense (PWM0FLTSEN), offset 0x800 Register 77: PWM1 Fault Pin Logic Sense (PWM1FLTSEN), offset 0x880 Register 78: PWM2 Fault Pin Logic Sense (PWM2FLTSEN), offset 0x900 Register 79: PWM3 Fault Pin Logic Sense (PWM3FLTSEN), offset 0x980 This register defines the PWM fault pin logic sense. PWMn Fault Pin Logic Sense (PWMnFLTSEN) PWM0 base: 0x4002.8000 Offset 0x800 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 FAULT3 FAULT2 FAULT1 FAULT0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 FAULT3 RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Fault3 Sense Value Description 2 FAULT2 RW 0 0 An error is indicated if the Fault3 signal is High. 1 An error is indicated if the Fault3 signal is Low. Fault2 Sense Value Description 1 FAULT1 RW 0 0 An error is indicated if the Fault2 signal is High. 1 An error is indicated if the Fault2 signal is Low. Fault1 Sense Value Description 0 FAULT0 RW 0 0 An error is indicated if the Fault1 signal is High. 1 An error is indicated if the Fault1 signal is Low. Fault0 Sense Value Description 0 An error is indicated if the Fault0 signal is High. 1 An error is indicated if the Fault0 signal is Low. June 18, 2014 1739 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 80: PWM0 Fault Status 0 (PWM0FLTSTAT0), offset 0x804 Register 81: PWM1 Fault Status 0 (PWM1FLTSTAT0), offset 0x884 Register 82: PWM2 Fault Status 0 (PWM2FLTSTAT0), offset 0x904 Register 83: PWM3 Fault Status 0 (PWM3FLTSTAT0), offset 0x984 Along with the PWMnFLTSTAT1 register, this register provides status regarding the fault condition inputs. If the LATCH bit in the PWMnCTL register is clear, the contents of the PWMnFLTSTAT0 register are read-only (RO) and provide the current state of the MnFAULTn inputs. If the LATCH bit in the PWMnCTL register is set, the contents of the PWMnFLTSTAT0 register are read / write 1 to clear (RW1C) and provide a latched version of the MnFAULTn inputs. In this mode, the register bits are cleared by writing a 1 to a set bit. The MnFAULTn inputs are recorded after their sense is adjusted in the generator. The contents of this register can only be written if the fault source extensions are enabled (the FLTSRC bit in the PWMnCTL register is set). Note: The fault status registers, PWMnFLTSTAT0 and PWMnFLTSTAT1, reflect the status of all fault sources, regardless of what fault sources are enabled for that particular generator. PWMn Fault Status 0 (PWMnFLTSTAT0) PWM0 base: 0x4002.8000 Offset 0x804 Type -, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 3 2 1 0 FAULT3 FAULT2 FAULT1 FAULT0 0 0 0 0 Bit/Field Name Type Reset Description 31:4 reserved RO 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 3 FAULT3 - 0 Fault Input 3 If the PWMnCTL register LATCH bit is clear, this bit is RO and represents the current state of the MnFAULT3 input signal after the logic sense adjustment. If the PWMnCTL register LATCH bit is set, this bit is RW1C and represents a sticky version of the MnFAULT3 input signal after the logic sense adjustment. ■ If FAULT3 is set, the input transitioned to the active state previously. ■ If FAULT3 is clear, the input has not transitioned to the active state since the last time it was cleared. ■ The FAULT3 bit is cleared by writing it with the value 1. 1740 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset Description 2 FAULT2 - 0 Fault Input 2 If the PWMnCTL register LATCH bit is clear, this bit is RO and represents the current state of the MnFAULT2 input signal after the logic sense adjustment. If the PWMnCTL register LATCH bit is set, this bit is RW1C and represents a sticky version of the MnFAULT2 input signal after the logic sense adjustment. 1 FAULT1 - 0 ■ If FAULT2 is set, the input transitioned to the active state previously. ■ If FAULT2 is clear, the input has not transitioned to the active state since the last time it was cleared. ■ The FAULT2 bit is cleared by writing it with the value 1. Fault Input 1 If the PWMnCTL register LATCH bit is clear, this bit is RO and represents the current state of the MnFAULT1 input signal after the logic sense adjustment. If the PWMnCTL register LATCH bit is set, this bit is RW1C and represents a sticky version of the MnFAULT1 input signal after the logic sense adjustment. 0 FAULT0 - 0 ■ If FAULT1 is set, the input transitioned to the active state previously. ■ If FAULT1 is clear, the input has not transitioned to the active state since the last time it was cleared. ■ The FAULT1 bit is cleared by writing it with the value 1. Fault Input 0 If the PWMnCTL register LATCH bit is clear, this bit is RO and represents the current state of the input signal after the logic sense adjustment. If the PWMnCTL register LATCH bit is set, this bit is RW1C and represents a sticky version of the input signal after the logic sense adjustment. ■ If FAULT0 is set, the input transitioned to the active state previously. ■ If FAULT0 is clear, the input has not transitioned to the active state since the last time it was cleared. ■ The FAULT0 bit is cleared by writing it with the value 1. June 18, 2014 1741 Texas Instruments-Production Data Pulse Width Modulator (PWM) Register 84: PWM0 Fault Status 1 (PWM0FLTSTAT1), offset 0x808 Register 85: PWM1 Fault Status 1 (PWM1FLTSTAT1), offset 0x888 Register 86: PWM2 Fault Status 1 (PWM2FLTSTAT1), offset 0x908 Register 87: PWM3 Fault Status 1 (PWM3FLTSTAT1), offset 0x988 Along with the PWMnFLTSTAT0 register, this register provides status regarding the fault condition inputs. If the LATCH bit in the PWMnCTL register is clear, the contents of the PWMnFLTSTAT1 register are read-only (RO) and provide the current state of the digital comparator triggers. If the LATCH bit in the PWMnCTL register is set, the contents of the PWMnFLTSTAT1 register are read / write 1 to clear (RW1C) and provide a latched version of the digital comparator triggers. In this mode, the register bits are cleared by writing a 1 to a set bit. The contents of this register can only be written if the fault source extensions are enabled (the FLTSRC bit in the PWMnCTL register is set). Note: The fault status registers, PWMnFLTSTAT0 and PWMnFLTSTAT1, reflect the status of all fault sources, regardless of what fault sources are enabled for that particular generator. PWMn Fault Status 1 (PWMnFLTSTAT1) PWM0 base: 0x4002.8000 Offset 0x808 Type -, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 reserved Type Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 Bit/Field Name Type Reset 31:8 reserved RO 0x0000.00 7 DCMP7 - 0 RO 0 RO 0 7 6 5 4 3 2 1 0 DCMP7 DCMP6 DCMP5 DCMP4 DCMP3 DCMP2 DCMP1 DCMP0 0 0 0 0 0 0 0 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Digital Comparator 7 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 7 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. ■ If DCMP7 is set, the trigger transitioned to the active state previously. ■ If DCMP7 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP7 bit is cleared by writing it with the value 1. 1742 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 6 DCMP6 - 0 Description Digital Comparator 6 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 6 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. 5 DCMP5 - 0 ■ If DCMP6 is set, the trigger transitioned to the active state previously. ■ If DCMP6 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP6 bit is cleared by writing it with the value 1. Digital Comparator 5 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 5 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. 4 DCMP4 - 0 ■ If DCMP5 is set, the trigger transitioned to the active state previously. ■ If DCMP5 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP5 bit is cleared by writing it with the value 1. Digital Comparator 4 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 4 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. 3 DCMP3 - 0 ■ If DCMP4 is set, the trigger transitioned to the active state previously. ■ If DCMP4 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP4 bit is cleared by writing it with the value 1. Digital Comparator 3 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 3 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. ■ If DCMP3 is set, the trigger transitioned to the active state previously. ■ If DCMP3 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP3 bit is cleared by writing it with the value 1. June 18, 2014 1743 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset 2 DCMP2 - 0 Description Digital Comparator 2 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 2 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. 1 DCMP1 - 0 ■ If DCMP2 is set, the trigger transitioned to the active state previously. ■ If DCMP2 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP2 bit is cleared by writing it with the value 1. Digital Comparator 1 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 1 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. 0 DCMP0 - 0 ■ If DCMP1 is set, the trigger transitioned to the active state previously. ■ If DCMP1 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP1 bit is cleared by writing it with the value 1. Digital Comparator 0 Trigger If the PWMnCTL register LATCH bit is clear, this bit represents the current state of the Digital Comparator 0 trigger input. If the PWMnCTL register LATCH bit is set, this bit represents a sticky version of the trigger. ■ If DCMP0 is set, the trigger transitioned to the active state previously. ■ If DCMP0 is clear, the trigger has not transitioned to the active state since the last time it was cleared. ■ The DCMP0 bit is cleared by writing it with the value 1. 1744 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 88: PWM Peripheral Properties (PWMPP), offset 0xFC0 The PWMPP register provides information regarding the properties of the PWM module. PWM Peripheral Properties (PWMPP) PWM0 base: 0x4002.8000 Offset 0xFC0 Type RO, reset 0x0000.0344 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 ONE EFAULT ESYNC RO 0 RO 0 RO 0 RO 0 RO 0 RO 1 RO 1 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 1 RO 0 RO 0 RO 0 RO 1 RO 0 RO 0 reserved Type Reset reserved Type Reset RO 0 FCNT GCNT Bit/Field Name Type Reset Description 31:11 reserved RO 0x0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 10 ONE RO 0x0 One-Shot Mode Value Description 9 EFAULT RO 0x1 0 One-shot modes are not available. 1 One-shot modes are available. Extended Fault Value Description 8 ESYNC RO 0x1 0 Extended fault capabilities are not available. 1 Extended fault capabilities are available. Extended Synchronization Value Description 7:4 FCNT RO 0x4 0 Extended synchronization is not available. 1 Extended synchronization is available. Fault Inputs Value Description 0x0 No fault inputs. 0x1 1 fault input. 0x2 2 fault input. 0x3 3 fault input. 0x4 4 fault input. 0x5 - 0xF reserved June 18, 2014 1745 Texas Instruments-Production Data Pulse Width Modulator (PWM) Bit/Field Name Type Reset Description 3:0 GCNT RO 0x4 Generators Value Description 0x0 No generators. 0x1 1 generator 0x2 2 generators 0x3 3 generators 0x4 4 generators 0x5 - 0xF reserved The number of PWM outputs is 2 times the number of PWM generators. 1746 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 89: PWM Clock Configuration (PWMCC), offset 0xFC8 The PWMCC register controls the clock source for the PWM module. PWM Clock Configuration (PWMCC) PWM0 base: 0x4002.8000 Offset 0xFC8 Type RW, reset 0x0000.0005 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RW 1 reserved Type Reset reserved Type Reset RO 0 USEPWM Bit/Field Name Type 31:9 reserved RO 8 USEPWM RW Reset RW 0 reserved RO 0 PWMDIV RW 0 RW 1 Description 0x0000.0000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 Use PWM Clock Divisor Value Description 7:3 reserved RO 0 2:0 PWMDIV RW 0x5 0 The system clock is the source of PWM unit clock. 1 The PWM clock divider is the source of PWM unit clock. Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. PWM Clock Divider This field specifies the PWM clock frequency as a division of the system clock. Value Description 0x0 /2 0x1 /4 0x2 /8 0x3 /16 0x4 /32 0x5 /64 0x6 - 0x7 reserved June 18, 2014 1747 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) 24 Quadrature Encoder Interface (QEI) A quadrature encoder, also known as a 2-channel incremental encoder, converts linear displacement into a pulse signal. By monitoring both the number of pulses and the relative phase of the two signals, you can track the position, direction of rotation, and speed. In addition, a third channel, or index signal, can be used to reset the position counter. The TM4C1294NCPDT quadrature encoder interface (QEI) module interprets the code produced by a quadrature encoder wheel to integrate position over time and determine direction of rotation. In addition, it can capture a running estimate of the velocity of the encoder wheel. The TM4C1294NCPDT microcontroller includes one QEI module with the following features: ■ Position integrator that tracks the encoder position ■ Programmable noise filter on the inputs ■ Velocity capture using built-in timer ■ The input frequency of the QEI inputs may be as high as 1/4 of the processor frequency (for example, 12.5 MHz for a 50-MHz system) ■ Interrupt generation on: – Index pulse – Velocity-timer expiration – Direction change – Quadrature error detection 24.1 Block Diagram Figure 24-1 on page 1749 provides an internal block diagram of a TM4C1294NCPDT QEI module. The PhA and PhB inputs shown in this diagram are the internal signals that enter the Quadrature Encoder after the external signals, PhAn and PhBn, have passed through inversion and swapping logic shown in Figure 24-2 on page 1750. The QEI module has the option of inverting and/or swapping the incoming signals. Note: Any references in this chapter to PhA and PhB refer to the internal PhA and PhB inputs that enter the Quadrature Encoder after the external signals, PhAn and PhBn, have passed through inversion and swapping logic that is enabled through the QEI Control (QEICTL) register. 1748 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 24-1. QEI Block Diagram QEILOAD Velocity Timer Control & Status QEITIME QEICTL QEISTAT Velocity Accumulator Velocity Predivider PhA PhB QEICOUNT QEISPEED clk Quadrature Encoder dir QEIMAXPOS Position Integrator QEIPOS IDX QEIINTEN Interrupt Control Interrupt QEIRIS QEIISC Figure 24-2 on page 1750 shows the logic that is provided to allow the PhAn and PhBn signals to be inverted and/or swapped. June 18, 2014 1749 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Figure 24-2. QEI Input Signal Logic PhAn QEICTL.INVA 1 0 QEICTL.INVB QEICTL.SWAP PhA PhBn 1 PhB clk Quadrature Encoder dir 0 QEICTL.SWAP 24.2 Signal Description The following table lists the external signals of the QEI module and describes the function of each. The QEI signals are alternate functions for some GPIO signals and default to be GPIO signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible GPIO pin placements for these QEI signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 770) should be set to choose the QEI function. The number in parentheses is the encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL) register (page 787) to assign the QEI signal to the specified GPIO port pin. For more information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742. Table 24-1. QEI Signals (128TQFP) Pin Name 24.3 Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description IDX0 84 PL3 (6) I TTL QEI module 0 index. PhA0 82 PL1 (6) I TTL QEI module 0 phase A. PhB0 83 PL2 (6) I TTL QEI module 0 phase B. Functional Description The QEI module interprets the two-bit gray code produced by a quadrature encoder wheel to integrate position over time and determine direction of rotation. In addition, it can capture a running estimate of the velocity of the encoder wheel. The position integrator and velocity capture can be independently enabled, though the position integrator must be enabled before the velocity capture can be enabled. The two phase signals, PhAn and PhBn, can be swapped before being interpreted by the QEI module to change the meaning 1750 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller of forward and backward and to correct for miswiring of the system. Alternatively, the phase signals can be interpreted as a clock and direction signal as output by some encoders. The QEI module input signals have a digital noise filter on them that can be enabled to prevent spurious operation. The noise filter requires that the inputs be stable for a specified number of consecutive clock cycles before updating the edge detector. The filter is enabled by the FILTEN bit in the QEI Control (QEICTL) register. The frequency of the input update is programmable using the FILTCNT bit field in the QEICTL register. The QEI module supports two modes of signal operation: quadrature phase mode and clock/direction mode. In quadrature phase mode, the encoder produces two clocks that are 90 degrees out of phase; the edge relationship is used to determine the direction of rotation. In clock/direction mode, the encoder produces a clock signal to indicate steps and a direction signal to indicate the direction of rotation. This mode is determined by the SIGMODE bit of the QEICTL register (see page 1755). When the QEI module is set to use the quadrature phase mode (SIGMODE bit is clear), the capture mode for the position integrator can be set to update the position counter on every edge of the PhA signal or to update on every edge of both PhA and PhB. Updating the position counter on every PhA and PhB edge provides more positional resolution at the cost of less range in the positional counter. When edges on PhA lead edges on PhB, the position counter is incremented. When edges on PhB lead edges on PhA, the position counter is decremented. When a rising and falling edge pair is seen on one of the phases without any edges on the other, the direction of rotation has changed. The positional counter is automatically reset on one of two conditions: sensing the index pulse or reaching the maximum position value. The reset mode is determined by the RESMODE bit of the QEICTL register. When RESMODE is set, the positional counter is reset when the index pulse is sensed. This mode limits the positional counter to the values [0:N-1], where N is the number of phase edges in a full revolution of the encoder wheel. The QEI Maximum Position (QEIMAXPOS) register must be programmed with N-1 so that the reverse direction from position 0 can move the position counter to N-1. In this mode, the position register contains the absolute position of the encoder relative to the index (or home) position once an index pulse has been seen. When RESMODE is clear, the positional counter is constrained to the range [0:M], where M is the programmable maximum value. The index pulse is ignored by the positional counter in this mode. Velocity capture uses a configurable timer and a count register. The timer counts the number of phase edges (using the same configuration as for the position integrator) in a given time period. The edge count from the previous time period is available to the controller via the QEI Velocity (QEISPEED) register, while the edge count for the current time period is being accumulated in the QEI Velocity Counter (QEICOUNT) register. As soon as the current time period is complete, the total number of edges counted in that time period is made available in the QEISPEED register (overwriting the previous value), the QEICOUNT register is cleared, and counting commences on a new time period. The number of edges counted in a given time period is directly proportional to the velocity of the encoder. Figure 24-3 on page 1752 shows how the TM4C1294NCPDT quadrature encoder converts the phase input signals into clock pulses, the direction signal, and how the velocity predivider operates (in Divide by 4 mode). June 18, 2014 1751 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Figure 24-3. Quadrature Encoder and Velocity Predivider Operation PhA PhB clk clkdiv dir pos -1 -1 -1 -1 -1 -1 -1 -1 -1 rel +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 +1 +1 +1 The period of the timer is configurable by specifying the load value for the timer in the QEI Timer Load (QEILOAD) register. When the timer reaches zero, an interrupt can be triggered, and the hardware reloads the timer with the QEILOAD value and continues to count down. At lower encoder speeds, a longer timer period is required to be able to capture enough edges to have a meaningful result. At higher encoder speeds, both a shorter timer period and/or the velocity predivider can be used. The following equation converts the velocity counter value into an rpm value: rpm = (clock * (2 ^ VELDIV) * SPEED * 60) ÷ (LOAD * ppr * edges) where: clock is the controller clock rate ppr is the number of pulses per revolution of the physical encoder edges is 2 or 4, based on the capture mode set in the QEICTL register (2 for CAPMODE clear and 4 for CAPMODE set) For example, consider a motor running at 600 rpm. A 2048 pulse per revolution quadrature encoder is attached to the motor, producing 8192 phase edges per revolution. With a velocity predivider of ÷1 (VELDIV is clear) and clocking on both PhA and PhB edges, this results in 81,920 pulses per second (the motor turns 10 times per second). If the timer were clocked at 10,000 Hz, and the load value was 2,500 (¼ of a second), it would count 20,480 pulses per update. Using the above equation: rpm = (10000 * 1 * 20480 * 60) ÷ (2500 * 2048 * 4) = 600 rpm Now, consider that the motor is sped up to 3000 rpm. This results in 409,600 pulses per second, or 102,400 every ¼ of a second. Again, the above equation gives: rpm = (10000 * 1 * 102400 * 60) ÷ (2500 * 2048 * 4) = 3000 rpm Care must be taken when evaluating this equation because intermediate values may exceed the capacity of a 32-bit integer. In the above examples, the clock is 10,000 and the divider is 2,500; both could be predivided by 100 (at compile time if they are constants) and therefore be 100 and 25. In fact, if they were compile-time constants, they could also be reduced to a simple multiply by 4, cancelled by the ÷4 for the edge-count factor. Important: Reducing constant factors at compile time is the best way to control the intermediate values of this equation and reduce the processing requirement of computing this equation. The division can be avoided by selecting a timer load value such that the divisor is a power of 2; a simple shift can therefore be done in place of the division. For encoders with a power of 2 pulses per revolution, the load value can be a power of 2. For other encoders, a load value must be selected such that the product is very close to a power of 2. For example, a 100 pulse-per-revolution encoder 1752 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller could use a load value of 82, resulting in 32,800 as the divisor, which is 0.09% above 214. In this case a shift by 15 would be an adequate approximation of the divide in most cases. If absolute accuracy were required, the microcontroller's divide instruction could be used. The QEI module can produce a controller interrupt on several events: phase error, direction change, reception of the index pulse, and expiration of the velocity timer. Standard masking, raw interrupt status, interrupt status, and interrupt clear capabilities are provided. 24.4 Initialization and Configuration The following example shows how to configure the Quadrature Encoder module to read back an absolute position: 1. Enable the QEI clock using the RCGCQEI register in the System Control module (see page 399). 2. Enable the clock to the appropriate GPIO module via the RCGCGPIO register in the System Control module (see page 382). 3. In the GPIO module, enable the appropriate pins for their alternate function using the GPIOAFSEL register. To determine which GPIOs to configure, see Table 26-4 on page 1797. 4. Configure the PMCn fields in the GPIOPCTL register to assign the QEI signals to the appropriate pins (see page 787 and Table 26-5 on page 1808). 5. Configure the quadrature encoder to capture edges on both signals and maintain an absolute position by resetting on index pulses. A 1000-line encoder with four edges per line, results in 4000 pulses per revolution; therefore, set the maximum position to 3999 (0xF9F) as the count is zero-based. ■ Write the QEICTL register with the value of 0x0000.0018. ■ Write the QEIMAXPOS register with the value of 0x0000.0F9F. 6. Enable the quadrature encoder by setting bit 0 of the QEICTL register. Note: Once the QEI module has been enabled by setting the ENABLE bit in the QEICTL register, it cannot be disabled. The only way to clear the ENABLE bit is to reset the module using the Quadrature Encoder Interface Software Reset (SRQEI) register. 7. Delay until the encoder position is required. 8. Read the encoder position by reading the QEI Position (QEIPOS) register value. Note: 24.5 If the application requires the quadrature encoder to have a specific initial position, this value must be programmed in the QEIPOS register after the quadrature encoder has been enabled by setting the ENABLE bit in the QEICTL register. Register Map Table 24-2 on page 1754 lists the QEI registers. The offset listed is a hexadecimal increment to the register's address, relative to the module's base address: ■ QEI0: 0x4002.C000 June 18, 2014 1753 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Note that the QEI module clock must be enabled before the registers can be programmed (see page 399). There must be a delay of 3 system clocks after the QEI module clock is enabled before any QEI module registers are accessed. Table 24-2. QEI Register Map Type Reset Description See page QEICTL RW 0x0000.0000 QEI Control 1755 0x004 QEISTAT RO 0x0000.0000 QEI Status 1758 0x008 QEIPOS RW 0x0000.0000 QEI Position 1759 0x00C QEIMAXPOS RW 0x0000.0000 QEI Maximum Position 1760 0x010 QEILOAD RW 0x0000.0000 QEI Timer Load 1761 0x014 QEITIME RO 0x0000.0000 QEI Timer 1762 0x018 QEICOUNT RO 0x0000.0000 QEI Velocity Counter 1763 0x01C QEISPEED RO 0x0000.0000 QEI Velocity 1764 0x020 QEIINTEN RW 0x0000.0000 QEI Interrupt Enable 1765 0x024 QEIRIS RO 0x0000.0000 QEI Raw Interrupt Status 1767 0x028 QEIISC RW1C 0x0000.0000 QEI Interrupt Status and Clear 1769 Offset Name 0x000 24.6 Register Descriptions The remainder of this section lists and describes the QEI registers, in numerical order by address offset. 1754 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 1: QEI Control (QEICTL), offset 0x000 This register contains the configuration of the QEI module. Separate enables are provided for the quadrature encoder and the velocity capture blocks; the quadrature encoder must be enabled in order to capture the velocity, but the velocity does not need to be captured in applications that do not need it. The phase signal interpretation, phase swap, Position Update mode, Position Reset mode, and velocity predivider are all set via this register. QEI Control (QEICTL) QEI0 base: 0x4002.C000 Offset 0x000 Type RW, reset 0x0000.0000 31 30 29 28 27 26 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 FILTEN STALLEN RW 0 RW 0 25 24 23 22 21 20 19 18 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 10 9 8 7 6 5 4 3 2 1 0 INVI INVB INVA SWAP ENABLE RW 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset RO 0 RO 0 17 16 FILTCNT VELDIV RW 0 RW 0 VELEN RESMODE CAPMODE SIGMODE RW 0 RW 0 RW 0 RW 0 RW 0 Bit/Field Name Type Reset Description 31:20 reserved RO 0x000 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 19:16 FILTCNT RW 0x0 Input Filter Prescale Count This field controls the frequency of the input update. When this field is clear, the input is sampled after 2 system clocks. When this field ix 0x1, the input is sampled after 3 system clocks. Similarly, when this field is 0xF, the input is sampled after 17 clocks. 15:14 reserved RO 0x0 13 FILTEN RW 0 Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Enable Input Filter Value Description 12 STALLEN RW 0 0 The QEI inputs are not filtered. 1 Enables the digital noise filter on the QEI input signals. Inputs must be stable for 3 consecutive clock edges before the edge detector is updated. Stall QEI Value Description 0 The QEI module does not stall when the microcontroller is stopped by a debugger. 1 The QEI module stalls when the microcontroller is stopped by a debugger. June 18, 2014 1755 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Bit/Field Name Type Reset 11 INVI RW 0 Description Invert Index Pulse Value Description 10 INVB RW 0 0 No effect. 1 Inverts the IDX input. Invert PhB Value Description 9 INVA RW 0 0 No effect. 1 Inverts the PhBn input. Invert PhA Value Description 8:6 VELDIV RW 0x0 0 No effect. 1 Inverts the PhAn input. Predivide Velocity This field defines the predivider of the input quadrature pulses before being applied to the QEICOUNT accumulator. Value Predivider 5 VELEN RW 0 0x0 ÷1 0x1 ÷2 0x2 ÷4 0x3 ÷8 0x4 ÷16 0x5 ÷32 0x6 ÷64 0x7 ÷128 Capture Velocity Value Description 4 RESMODE RW 0 0 No effect. 1 Enables capture of the velocity of the quadrature encoder. Reset Mode Value Description 0 The position counter is reset when it reaches the maximum as defined by the MAXPOS field in the QEIMAXPOS register. 1 The position counter is reset when the index pulse is captured. 1756 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Bit/Field Name Type Reset 3 CAPMODE RW 0 Description Capture Mode Note: When SIGMODE=1, the CAPMODE setting is not applicable and is reserved. Value Description 2 SIGMODE RW 0 0 Only the PhA edges are counted. 1 The PhA and PhB edges are counted, providing twice the positional resolution but half the range. Signal Mode Value Description 1 SWAP RW 0 0 The internal PhA and PhB signals operate as quadrature phase signals. 1 The internal PhA input operates as the clock (CLK) signal and the internal PhB input operates as the direction (DIR) signal. Swap Signals Note if the INVA or INVB bit are set, the inversion of the signals occur prior to the swap. Value Description 0 ENABLE RW 0 0 No effect. 1 Swaps the PhAn and PhBn signals. Enable QEI Value Description 0 No effect. 1 Enables the quadrature encoder module. Note: Once the QEI module has been enabled by setting the ENABLE bit, it cannot be disabled. The only way to clear the ENABLE bit is to reset the module using the Quadrature Encoder Interface Software Reset (SRQEI) register. June 18, 2014 1757 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Register 2: QEI Status (QEISTAT), offset 0x004 This register provides status about the operation of the QEI module. QEI Status (QEISTAT) QEI0 base: 0x4002.C000 Offset 0x004 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 DIRECTION ERROR RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:2 reserved RO 0x0000.000 1 DIRECTION RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Direction of Rotation Indicates the direction the encoder is rotating. Value Description 0 ERROR RO 0 0 The encoder is rotating forward. 1 The encoder is rotating in reverse. Error Detected Value Description 0 No error. 1 An error was detected in the gray code sequence (that is, both signals changing at the same time). 1758 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 3: QEI Position (QEIPOS), offset 0x008 This register contains the current value of the position integrator. The value is updated by the status of the QEI phase inputs and can be set to a specific value by writing to it. QEI Position (QEIPOS) QEI0 base: 0x4002.C000 Offset 0x008 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 POSITION Type Reset POSITION Type Reset Bit/Field Name Type 31:0 POSITION RW Reset RW 0 Description 0x0000.0000 Current Position Integrator Value The current value of the position integrator. June 18, 2014 1759 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Register 4: QEI Maximum Position (QEIMAXPOS), offset 0x00C This register contains the maximum value of the position integrator. When moving forward, the position register resets to zero when it increments past this value. When moving in reverse, the position register resets to this value when it decrements from zero. QEI Maximum Position (QEIMAXPOS) QEI0 base: 0x4002.C000 Offset 0x00C Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 MAXPOS Type Reset MAXPOS Type Reset Bit/Field Name Type 31:0 MAXPOS RW Reset Description 0x0000.0000 Maximum Position Integrator Value The maximum value of the position integrator. 1760 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 5: QEI Timer Load (QEILOAD), offset 0x010 This register contains the load value for the velocity timer. Because this value is loaded into the timer on the clock cycle after the timer is zero, this value should be one less than the number of clocks in the desired period. So, for example, to have 2000 decimal clocks per timer period, this register should contain 1999 decimal. QEI Timer Load (QEILOAD) QEI0 base: 0x4002.C000 Offset 0x010 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 LOAD Type Reset LOAD Type Reset Bit/Field Name Type 31:0 LOAD RW Reset Description 0x0000.0000 Velocity Timer Load Value The load value for the velocity timer. June 18, 2014 1761 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Register 6: QEI Timer (QEITIME), offset 0x014 This register contains the current value of the velocity timer. This counter does not increment when the VELEN bit in the QEICTL register is clear. QEI Timer (QEITIME) QEI0 base: 0x4002.C000 Offset 0x014 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 TIME Type Reset TIME Type Reset Bit/Field Name Type 31:0 TIME RO Reset Description 0x0000.0000 Velocity Timer Current Value The current value of the velocity timer. 1762 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 7: QEI Velocity Counter (QEICOUNT), offset 0x018 This register contains the running count of velocity pulses for the current time period. Because this count is a running total, the time period to which it applies cannot be known with precision (that is, a read of this register does not necessarily correspond to the time returned by the QEITIME register because there is a small window of time between the two reads, during which either value may have changed). The QEISPEED register should be used to determine the actual encoder velocity; this register is provided for information purposes only. This counter does not increment when the VELEN bit in the QEICTL register is clear. QEI Velocity Counter (QEICOUNT) QEI0 base: 0x4002.C000 Offset 0x018 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 COUNT Type Reset COUNT Type Reset Bit/Field Name Type 31:0 COUNT RO Reset Description 0x0000.0000 Velocity Pulse Count The running total of encoder pulses during this velocity timer period. June 18, 2014 1763 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Register 8: QEI Velocity (QEISPEED), offset 0x01C This register contains the most recently measured velocity of the quadrature encoder. This value corresponds to the number of velocity pulses counted in the previous velocity timer period. This register does not update when the VELEN bit in the QEICTL register is clear. QEI Velocity (QEISPEED) QEI0 base: 0x4002.C000 Offset 0x01C Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 SPEED Type Reset SPEED Type Reset Bit/Field Name Type 31:0 SPEED RO Reset Description 0x0000.0000 Velocity The measured speed of the quadrature encoder in pulses per period. 1764 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 9: QEI Interrupt Enable (QEIINTEN), offset 0x020 This register contains enables for each of the QEI module interrupts. An interrupt is asserted to the interrupt controller if the corresponding bit in this register is set. QEI Interrupt Enable (QEIINTEN) QEI0 base: 0x4002.C000 Offset 0x020 Type RW, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 INTERROR INTDIR INTTIMER INTINDEX RO 0 RO 0 RO 0 RO 0 RO 0 RW 0 RW 0 RW 0 RW 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 INTERROR RW 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Phase Error Interrupt Enable Note: The INTERROR bit is only applicable when the QEI is operating in quadrature phase mode (SIGMODE=0) and should be masked when SIGMODE =1. Value Description 2 INTDIR RW 0 0 The INTERROR interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the INTERROR bit in the QEIRIS register is set. Direction Change Interrupt Enable Value Description 1 INTTIMER RW 0 0 The INTDIR interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the INTDIR bit in the QEIRIS register is set. Timer Expires Interrupt Enable Value Description 0 The INTTIMER interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the INTTIMER bit in the QEIRIS register is set. June 18, 2014 1765 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Bit/Field Name Type Reset 0 INTINDEX RW 0 Description Index Pulse Detected Interrupt Enable Value Description 0 The INTINDEX interrupt is suppressed and not sent to the interrupt controller. 1 An interrupt is sent to the interrupt controller when the INTINDEX bit in the QEIRIS register is set. 1766 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 10: QEI Raw Interrupt Status (QEIRIS), offset 0x024 This register provides the current set of interrupt sources that are asserted, regardless of whether they cause an interrupt to be asserted to the controller (configured through the QEIINTEN register). If a bit is set, the latched event has occurred; if a bit is clear, the event in question has not occurred. QEI Raw Interrupt Status (QEIRIS) QEI0 base: 0x4002.C000 Offset 0x024 Type RO, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 INTERROR INTDIR INTTIMER INTINDEX RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 INTERROR RO 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Phase Error Detected Note: The INTERROR bit is only applicable when the QEI is operating in quadrature phase mode (SIGMODE=0). Value Description 0 An interrupt has not occurred. 1 A phase error has been detected. This bit is cleared by writing a 1 to the INTERROR bit in the QEIISC register. 2 INTDIR RO 0 Direction Change Detected Value Description 0 An interrupt has not occurred. 1 The rotation direction has changed This bit is cleared by writing a 1 to the INTDIR bit in the QEIISC register. 1 INTTIMER RO 0 Velocity Timer Expired Value Description 0 An interrupt has not occurred. 1 The velocity timer has expired. This bit is cleared by writing a 1 to the INTTIMER bit in the QEIISC register. June 18, 2014 1767 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Bit/Field Name Type Reset 0 INTINDEX RO 0 Description Index Pulse Asserted Value Description 0 An interrupt has not occurred. 1 The index pulse has occurred. This bit is cleared by writing a 1 to the INTINDEX bit in the QEIISC register. 1768 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Register 11: QEI Interrupt Status and Clear (QEIISC), offset 0x028 This register provides the current set of interrupt sources that are asserted to the controller. If a bit is set, the latched event has occurred and is enabled to generate an interrupt; if a bit is clear the event in question has not occurred or is not enabled to generate an interrupt. This register is RW1C; writing a 1 to a bit position clears the bit and the corresponding interrupt reason. QEI Interrupt Status and Clear (QEIISC) QEI0 base: 0x4002.C000 Offset 0x028 Type RW1C, reset 0x0000.0000 31 30 29 28 27 26 25 24 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 15 14 13 12 11 10 9 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 23 22 21 20 19 18 17 16 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 8 7 6 5 4 3 2 1 0 INTERROR INTDIR INTTIMER INTINDEX RO 0 RO 0 RO 0 RO 0 RO 0 RW1C 0 RW1C 0 RW1C 0 RW1C 0 reserved Type Reset reserved Type Reset Bit/Field Name Type Reset 31:4 reserved RO 0x0000.000 3 INTERROR RW1C 0 Description Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. Phase Error Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTERROR bits in the QEIRIS register and the QEIINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTERROR bit in the QEIRIS register. 2 INTDIR RW1C 0 Direction Change Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTDIR bits in the QEIRIS register and the QEIINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTDIR bit in the QEIRIS register. 1 INTTIMER RW1C 0 Velocity Timer Expired Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTTIMER bits in the QEIRIS register and the QEIINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTTIMER bit in the QEIRIS register. June 18, 2014 1769 Texas Instruments-Production Data Quadrature Encoder Interface (QEI) Bit/Field Name Type Reset 0 INTINDEX RW1C 0 Description Index Pulse Interrupt Value Description 0 No interrupt has occurred or the interrupt is masked. 1 The INTINDEX bits in the QEIRIS register and the QEIINTEN registers are set, providing an interrupt to the interrupt controller. This bit is cleared by writing a 1. Clearing this bit also clears the INTINDEX bit in the QEIRIS register. 1770 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 25 Pin Diagram The TM4C1294NCPDT microcontroller pin diagram is shown below. Each GPIO signal is identified by its GPIO port unless it defaults to an alternate function on reset. In this case, the GPIO port name is followed by the default alternate function. To see a complete list of possible functions for each pin, see Table 26-5 on page 1808. Figure 25-1. 128-Pin TQFP Package Pin Diagram June 18, 2014 1771 Texas Instruments-Production Data Signal Tables 26 Signal Tables The following tables list the signals available for each pin. Signals are configured as GPIOs on reset, except for those noted below. Use the GPIOAMSEL register (see page 786) to select analog mode. For a GPIO pin to be used for an alternate digital function, the corresponding bit in the GPIOAFSEL register (see page 770) must be set. Further pin muxing options are provided through the PMCx bit field in the GPIOPCTL register (see page 787), which selects one of several available peripheral functions for that GPIO. Important: Table 10-1 on page 743 shows special consideration GPIO pins. Most GPIO pins are configured as GPIOs and tri-stated by default (GPIOAFSEL=0, GPIODEN=0, GPIOPDR=0, GPIOPUR=0, and GPIOPCTL=0). Special consideration pins may be programed to a non-GPIO function or may have special commit controls out of reset. In addition, a Power-On-Reset (POR) returns these GPIO to their original special consideration state. Table 26-1. GPIO Pins With Special Considerations GPIO Pins Default Reset State PC[3:0] JTAG/SWD GPIOAFSEL GPIODEN GPIOPDR GPIOPUR GPIOPCTL GPIOCR 1 1 0 1 0x1 0 a 0 0 0 0 0x0 0 a 0 0 0 0 0x0 0 PD[7] GPIO PE[7] GPIO a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the pin in the GPIOLOCK register and uncommitting it by setting the GPIOCR register. Table 26-2 on page 1773 shows the pin-to-signal-name mapping, including functional characteristics of the signals. Each possible alternate analog and digital function is listed for each pin. Table 26-3 on page 1785 lists the signals in alphabetical order by signal name. If it is possible for a signal to be on multiple pins, each possible pin assignment is listed. The "Pin Mux" column indicates the GPIO and the encoding needed in the PMCx bit field in the GPIOPCTL register. Table 26-4 on page 1797 groups the signals by functionality, except for GPIOs. If it is possible for a signal to be on multiple pins, each possible pin assignment is listed. Table 26-5 on page 1808 lists the GPIO pins and their analog and digital alternate functions. The AINx analog signals go through an isolation circuit before reaching their circuitry. These signals are configured by clearing the corresponding DEN bit in the GPIO Digital Enable (GPIODEN) register and setting the corresponding AMSEL bit in the GPIO Analog Mode Select (GPIOAMSEL) register. Other analog signals are 3.3-V tolerant and are connected directly to their circuitry (C0-, C0+, C1-, C1+, C2-, C2+, USB0VBUS, USB0ID). These signals are configured by clearing the DEN bit in the GPIO Digital Enable (GPIODEN) register. The digital signals are enabled by setting the appropriate bit in the GPIO Alternate Function Select (GPIOAFSEL) and GPIODEN registers and configuring the PMCx bit field in the GPIO Port Control (GPIOPCTL) register to the numeric enoding shown in the table below. Table entries that are shaded gray are the default values for the corresponding GPIO pin. Table 26-6 on page 1811 lists the signals based on number of possible pin assignments. This table can be used to plan how to configure the pins for a particular functionality. Application Note AN01274 Configuring Tiva™ C Series Microcontrollers with Pin Multiplexing provides an overview of the pin muxing implementation, an explanation of how a system designer defines a pin configuration, and examples of the pin configuration process. 1772 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Note: 26.1 All digital inputs are Schmitt triggered. Signals by Pin Number Table 26-2. Signals by Pin Number Pin Number 1 2 3 4 5 6 7 8 Pin Name Pin Type PD0 I/O Buffer Type Description TTL AIN15 I Analog GPIO port D bit 0. Analog-to-digital converter input 15. C0o O TTL Analog comparator 0 output. I2C7SCL I/O OD I2C module 7 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. SSI2XDAT1 I/O TTL SSI Module 2 Bi-directional Data Pin 1 (SSI2RX in Legacy SSI Mode). T0CCP0 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 0. PD1 I/O TTL GPIO port D bit 1. AIN14 I Analog C1o O TTL Analog comparator 1 output. I2C7SDA I/O OD I2C module 7 data. SSI2XDAT0 I/O TTL SSI Module 2 Bi-directional Data Pin 0 (SSI2TX in Legacy SSI Mode). T0CCP1 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 1. PD2 I/O TTL GPIO port D bit 2. AIN13 I Analog Analog-to-digital converter input 14. Analog-to-digital converter input 13. C2o O TTL Analog comparator 2 output. I2C8SCL I/O OD I2C module 8 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. SSI2Fss I/O TTL SSI module 2 frame signal. T1CCP0 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 0. GPIO port D bit 3. PD3 I/O TTL AIN12 I Analog I2C8SDA I/O OD I2C module 8 data. SSI2Clk I/O TTL SSI module 2 clock. T1CCP1 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 1. Analog-to-digital converter input 12. PQ0 I/O TTL GPIO port Q bit 0. EPI0S20 I/O TTL EPI module 0 signal 20. SSI3Clk I/O TTL SSI module 3 clock. PQ1 I/O TTL GPIO port Q bit 1. EPI0S21 I/O TTL EPI module 0 signal 21. SSI3Fss I/O TTL SSI module 3 frame signal. VDD - Power Positive supply for I/O and some logic. VDDA - Power The positive supply for the analog circuits (ADC, Analog Comparators, etc.). These are separated from VDD to minimize the electrical noise contained on VDD from affecting the analog functions. VDDA pins must be supplied with a voltage that meets the specification in , regardless of system implementation. June 18, 2014 1773 Texas Instruments-Production Data Signal Tables Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type Buffer Type Description VREFA+ - Analog A reference voltage used to specify the voltage at which the ADC converts to a maximum value. This pin is used in conjunction with GNDA. The voltage that is applied to VREFA+ is the voltage with which an AINn signal is converted to 4095. The VREFA+ voltage is limited to the range specified in Table 27-44 on page 1861. GNDA - Power The ground reference for the analog circuits (ADC, Analog Comparators, etc.). These are separated from GND to minimize the electrical noise contained on VDD from affecting the analog functions. PQ2 I/O TTL GPIO port Q bit 2. EPI0S22 I/O TTL EPI module 0 signal 22. SSI3XDAT0 I/O TTL SSI Module 3 Bi-directional Data Pin 0 (SSI3TX in Legacy SSI Mode). GPIO port E bit 3. 9 10 11 12 13 14 PE3 I/O TTL AIN0 I Analog U1DTR O TTL UART module 1 Data Terminal Ready modem status input signal. PE2 I/O TTL GPIO port E bit 2. AIN1 I Analog U1DCD I TTL UART module 1 Data Carrier Detect modem status input signal. PE1 I/O TTL GPIO port E bit 1. AIN2 I Analog U1DSR I TTL UART module 1 Data Set Ready modem output control line. PE0 I/O TTL GPIO port E bit 0. Analog-to-digital converter input 0. Analog-to-digital converter input 1. Analog-to-digital converter input 2. AIN3 I Analog U1RTS O TTL 16 VDD - Power Positive supply for I/O and some logic. 17 GND - Power Ground reference for logic and I/O pins. PK0 I/O TTL 15 Analog-to-digital converter input 3. UART module 1 Request to Send modem flow control output line. GPIO port K bit 0. AIN16 I Analog EPI0S0 I/O TTL EPI module 0 signal 0. U4Rx I TTL UART module 4 receive. GPIO port K bit 1. 18 Analog-to-digital converter input 16. PK1 I/O TTL AIN17 I Analog EPI0S1 I/O TTL EPI module 0 signal 1. U4Tx O TTL UART module 4 transmit. PK2 I/O TTL GPIO port K bit 2. 19 Analog-to-digital converter input 17. AIN18 I Analog EPI0S2 I/O TTL EPI module 0 signal 2. U4RTS O TTL UART module 4 Request to Send modem flow control output line. GPIO port K bit 3. 20 Analog-to-digital converter input 18. PK3 I/O TTL AIN19 I Analog EPI0S3 I/O TTL EPI module 0 signal 3. U4CTS I TTL UART module 4 Clear To Send modem flow control input signal. 21 Analog-to-digital converter input 19. 1774 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type PC7 I/O TTL C0- I Analog EPI0S4 I/O TTL EPI module 0 signal 4. U5Tx O TTL UART module 5 transmit. PC6 I/O TTL GPIO port C bit 6. 22 27 28 29 30 31 32 Analog comparator 0 negative input. C0+ I Analog I/O TTL EPI module 0 signal 5. U5Rx I TTL UART module 5 receive. PC5 I/O TTL GPIO port C bit 5. C1+ I Analog EPI0S6 I/O TTL EPI module 0 signal 6. RTCCLK O TTL Buffered version of the Hibernation module's 32.768-kHz clock. This signal is not output when the part is in Hibernate mode and before being configured after power-on reset. U7Tx O TTL UART module 7 transmit. PC4 I/O TTL GPIO port C bit 4. C1- I Analog EPI0S7 I/O TTL EPI module 0 signal 7. U7Rx I TTL UART module 7 receive. VDD - Power 25 26 GPIO port C bit 7. EPI0S5 23 24 Buffer Type Description Analog comparator 0 positive input. Analog comparator 1 positive input. Analog comparator 1 negative input. Positive supply for I/O and some logic. PQ3 I/O TTL GPIO port Q bit 3. EPI0S23 I/O TTL EPI module 0 signal 23. SSI3XDAT1 I/O TTL SSI Module 3 Bi-directional Data Pin 1 (SSI3RX in Legacy SSI Mode). VDD - Power PH0 I/O TTL GPIO port H bit 0. EPI0S0 I/O TTL EPI module 0 signal 0. U0RTS O TTL UART module 0 Request to Send modem flow control output signal. PH1 I/O TTL GPIO port H bit 1. EPI0S1 I/O TTL EPI module 0 signal 1. U0CTS I TTL UART module 0 Clear To Send modem flow control input signal. PH2 I/O TTL GPIO port H bit 2. EPI0S2 I/O TTL EPI module 0 signal 2. U0DCD I TTL UART module 0 Data Carrier Detect modem status input signal. PH3 I/O TTL GPIO port H bit 3. EPI0S3 I/O TTL EPI module 0 signal 3. U0DSR I TTL UART module 0 Data Set Ready modem output control line. Positive supply for I/O and some logic. June 18, 2014 1775 Texas Instruments-Production Data Signal Tables Table 26-2. Signals by Pin Number (continued) Pin Number 33 34 35 36 37 38 39 Pin Name Pin Type Buffer Type Description PA0 I/O TTL GPIO port A bit 0. CAN0Rx I TTL CAN module 0 receive. I2C9SCL I/O OD I2C module 9 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. T0CCP0 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 0. U0Rx I TTL UART module 0 receive. PA1 I/O TTL GPIO port A bit 1. CAN0Tx O TTL CAN module 0 transmit. I2C9SDA I/O OD I2C module 9 data. T0CCP1 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 1. U0Tx O TTL UART module 0 transmit. PA2 I/O TTL GPIO port A bit 2. I2C8SCL I/O OD I2C module 8 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. SSI0Clk I/O TTL SSI module 0 clock T1CCP0 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 0. U4Rx I TTL UART module 4 receive. PA3 I/O TTL GPIO port A bit 3. I2C8SDA I/O OD I2C module 8 data. SSI0Fss I/O TTL SSI module 0 frame signal T1CCP1 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 1. U4Tx O TTL UART module 4 transmit. PA4 I/O TTL GPIO port A bit 4. I2C7SCL I/O OD I2C module 7 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. SSI0XDAT0 I/O TTL SSI Module 0 Bi-directional Data Pin 0 (SSI0TX in Legacy SSI Mode). T2CCP0 I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 0. U3Rx I TTL UART module 3 receive. PA5 I/O TTL GPIO port A bit 5. I2C7SDA I/O OD I2C module 7 data. SSI0XDAT1 I/O TTL SSI Module 0 Bi-directional Data Pin 1 (SSI0RX in Legacy SSI Mode). T2CCP1 I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 1. U3Tx O TTL UART module 3 transmit. VDD - Power Positive supply for I/O and some logic. 1776 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-2. Signals by Pin Number (continued) Pin Number 40 41 Pin Name Pin Type Buffer Type Description PA6 I/O TTL GPIO port A bit 6. EPI0S8 I/O TTL EPI module 0 signal 8. I2C6SCL I/O OD I2C module 6 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. SSI0XDAT2 I/O TTL SSI Module 0 Bi-directional Data Pin 2. T3CCP0 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 0. U2Rx I TTL UART module 2 receive. USB0EPEN O TTL Optionally used in Host mode to control an external power source to supply power to the USB bus. PA7 I/O TTL GPIO port A bit 7. EPI0S9 I/O TTL EPI module 0 signal 9. I2C6SDA I/O OD I2C module 6 data. SSI0XDAT3 I/O TTL SSI Module 0 Bi-directional Data Pin 3. T3CCP1 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 1. U2Tx O TTL UART module 2 transmit. USB0EPEN O TTL Optionally used in Host mode to control an external power source to supply power to the USB bus. USB0PFLT I TTL Optionally used in Host mode by an external power source to indicate an error state by that power source. PF0 I/O TTL GPIO port F bit 0. EN0LED0 O TTL Ethernet 0 LED 0. M0PWM0 O TTL Motion Control Module 0 PWM 0. This signal is controlled by Module 0 PWM Generator 0. SSI3XDAT1 I/O TTL SSI Module 3 Bi-directional Data Pin 1 (SSI3RX in Legacy SSI Mode). TRD2 O TTL Trace data 2. 42 PF1 I/O TTL GPIO port F bit 1. EN0LED2 O TTL Ethernet 0 LED 2. M0PWM1 O TTL Motion Control Module 0 PWM 1. This signal is controlled by Module 0 PWM Generator 0. SSI3XDAT0 I/O TTL SSI Module 3 Bi-directional Data Pin 0 (SSI3TX in Legacy SSI Mode). TRD1 O TTL Trace data 1. 43 PF2 I/O TTL GPIO port F bit 2. M0PWM2 O TTL Motion Control Module 0 PWM 2. This signal is controlled by Module 0 PWM Generator 1. SSI3Fss I/O TTL SSI module 3 frame signal. TRD0 O TTL Trace data 0. 44 PF3 I/O TTL GPIO port F bit 3. M0PWM3 O TTL Motion Control Module 0 PWM 3. This signal is controlled by Module 0 PWM Generator 1. SSI3Clk I/O TTL SSI module 3 clock. TRCLK O TTL Trace clock. 45 June 18, 2014 1777 Texas Instruments-Production Data Signal Tables Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type Buffer Type Description PF4 I/O TTL GPIO port F bit 4. EN0LED1 O TTL Ethernet 0 LED 1. M0FAULT0 I TTL Motion Control Module 0 PWM Fault 0. SSI3XDAT2 I/O TTL SSI Module 3 Bi-directional Data Pin 2. TRD3 O TTL Trace data 3. 47 VDD - Power Positive supply for I/O and some logic. 48 GND - Power Ground reference for logic and I/O pins. PG0 I/O TTL GPIO port G bit 0. 46 49 50 51 EN0PPS O TTL Ethernet 0 Pulse-Per-Second (PPS) Output. EPI0S11 I/O TTL EPI module 0 signal 11. I2C1SCL I/O OD I2C module 1 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. M0PWM4 O TTL Motion Control Module 0 PWM 4. This signal is controlled by Module 0 PWM Generator 2. PG1 I/O TTL GPIO port G bit 1. EPI0S10 I/O TTL EPI module 0 signal 10. I2C1SDA I/O OD I2C module 1 data. M0PWM5 O TTL Motion Control Module 0 PWM 5. This signal is controlled by Module 0 PWM Generator 2. VDD - Power Positive supply for I/O and some logic. Positive supply for I/O and some logic. 52 VDD - Power 53 EN0RXIN I/O TTL Ethernet PHY negative receive differential input. Ethernet PHY positive receive differential input. 54 EN0RXIP I/O TTL 55 GND - Power 56 EN0TXON I/O TTL Ethernet PHY negative transmit differential output. Ethernet PHY positive transmit differential output. Ground reference for logic and I/O pins. 57 EN0TXOP I/O TTL 58 GND - Power Ground reference for logic and I/O pins. 59 RBIAS O Analog 4.87-kΩ resistor (1% precision) for Ethernet PHY. PK7 I/O TTL GPIO port K bit 7. EPI0S24 I/O TTL EPI module 0 signal 24. I2C4SDA I/O OD I2C module 4 data. M0FAULT2 I TTL Motion Control Module 0 PWM Fault 2. RTCCLK O TTL Buffered version of the Hibernation module's 32.768-kHz clock. This signal is not output when the part is in Hibernate mode and before being configured after power-on reset. U0RI I TTL UART module 0 Ring Indicator modem status input signal. PK6 I/O TTL GPIO port K bit 6. EN0LED1 O TTL Ethernet 0 LED 1. EPI0S25 I/O TTL EPI module 0 signal 25. I2C4SCL I/O OD I2C module 4 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. M0FAULT1 I TTL Motion Control Module 0 PWM Fault 1. 60 61 1778 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type Buffer Type Description PK5 I/O TTL GPIO port K bit 5. EN0LED2 O TTL Ethernet 0 LED 2. EPI0S31 I/O TTL EPI module 0 signal 31. I2C3SDA I/O OD I2C module 3 data. M0PWM7 O TTL Motion Control Module 0 PWM 7. This signal is controlled by Module 0 PWM Generator 3. PK4 I/O TTL GPIO port K bit 4. EN0LED0 O TTL Ethernet 0 LED 0. EPI0S32 I/O TTL EPI module 0 signal 32. I2C3SCL I/O OD I2C module 3 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. M0PWM6 O TTL Motion Control Module 0 PWM 6. This signal is controlled by Module 0 PWM Generator 3. WAKE I TTL An external input that brings the processor out of Hibernate mode when asserted. HIB O TTL An output that indicates the processor is in Hibernate mode. XOSC0 I Analog Hibernation module oscillator crystal input or an external clock reference input. Note that this is either a crystal or a 32.768-kHz oscillator for the Hibernation module RTC. XOSC1 O Analog Hibernation module oscillator crystal output. Leave unconnected when using a single-ended clock source. VBAT - Power Power source for the Hibernation module. It is normally connected to the positive terminal of a battery and serves as the battery backup/Hibernation module power-source supply. 69 VDD - Power Positive supply for I/O and some logic. 70 RST I TTL System reset input. PM7 I/O TTL GPIO port M bit 7. T5CCP1 I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 1. TMPR0 I/O TTL Tamper signal 0. U0RI I TTL UART module 0 Ring Indicator modem status input signal. 62 63 64 65 66 67 68 71 PM6 I/O TTL GPIO port M bit 6. T5CCP0 I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 0. TMPR1 I/O TTL Tamper signal 1. U0DSR I TTL UART module 0 Data Set Ready modem output control line. PM5 I/O TTL GPIO port M bit 5. T4CCP1 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 1. TMPR2 I/O TTL Tamper signal 2. U0DCD I TTL UART module 0 Data Carrier Detect modem status input signal. 72 73 PM4 I/O TTL GPIO port M bit 4. T4CCP0 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 0. TMPR3 I/O TTL Tamper signal 3. U0CTS I TTL UART module 0 Clear To Send modem flow control input signal. 74 June 18, 2014 1779 Texas Instruments-Production Data Signal Tables Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type PM3 I/O TTL GPIO port M bit 3. 75 EPI0S12 I/O TTL EPI module 0 signal 12. T3CCP1 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 1. PM2 I/O TTL GPIO port M bit 2. EPI0S13 I/O TTL EPI module 0 signal 13. T3CCP0 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 0. PM1 I/O TTL GPIO port M bit 1. EPI0S14 I/O TTL EPI module 0 signal 14. T2CCP1 I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 1. PM0 I/O TTL GPIO port M bit 0. EPI0S15 I/O TTL EPI module 0 signal 15. T2CCP0 I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 0. 79 VDD - Power Positive supply for I/O and some logic. 80 GND - Power Ground reference for logic and I/O pins. PL0 I/O TTL GPIO port L bit 0. EPI0S16 I/O TTL EPI module 0 signal 16. I2C2SDA I/O OD I2C module 2 data. M0FAULT3 I TTL Motion Control Module 0 PWM Fault 3. USB0D0 I/O TTL USB data 0. PL1 I/O TTL GPIO port L bit 1. EPI0S17 I/O TTL EPI module 0 signal 17. I2C2SCL I/O OD I2C module 2 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. 76 77 78 81 82 83 84 Buffer Type Description PhA0 I TTL QEI module 0 phase A. USB0D1 I/O TTL USB data 1. PL2 I/O TTL GPIO port L bit 2. C0o O TTL Analog comparator 0 output. EPI0S18 I/O TTL EPI module 0 signal 18. PhB0 I TTL QEI module 0 phase B. USB0D2 I/O TTL USB data 2. PL3 I/O TTL GPIO port L bit 3. C1o O TTL Analog comparator 1 output. EPI0S19 I/O TTL EPI module 0 signal 19. IDX0 I TTL QEI module 0 index. USB0D3 I/O TTL USB data 3. PL4 I/O TTL GPIO port L bit 4. EPI0S26 I/O TTL EPI module 0 signal 26. T0CCP0 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 0. USB0D4 I/O TTL USB data 4. 85 1780 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type Buffer Type Description PL5 I/O TTL GPIO port L bit 5. EPI0S33 I/O TTL EPI module 0 signal 33. T0CCP1 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 1. USB0D5 I/O TTL USB data 5. VDDC - Power Positive supply for most of the logic function, including the processor core and most peripherals. The voltage on this pin is 1.2 V and is supplied by the on-chip LDO. The VDDC pins should only be connected to each other and an external capacitor as specified in Table 27-15 on page 1834 . OSC0 I Analog Main oscillator crystal input or an external clock reference input. OSC1 O Analog Main oscillator crystal output. Leave unconnected when using a single-ended clock source. VDD - Power Positive supply for I/O and some logic. PB2 I/O TTL GPIO port B bit 2. EPI0S27 I/O TTL EPI module 0 signal 27. I2C0SCL I/O OD I2C module 0 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. T5CCP0 I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 0. USB0STP O TTL Asserted by the USB controller to signal the end of a USB transmit packet or register write operation. PB3 I/O TTL GPIO port B bit 3. EPI0S28 I/O TTL EPI module 0 signal 28. I2C0SDA I/O OD I2C module 0 data. T5CCP1 I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 1. USB0CLK O TTL 60-MHz clock to the external PHY. PL7 I/O TTL GPIO port L bit 7. T1CCP1 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 1. USB0DM I/O Analog PL6 I/O TTL GPIO port L bit 6. T1CCP0 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 0. USB0DP I/O Analog 86 87 88 89 90 91 92 93 94 95 Bidirectional differential data pin (D- per USB specification) for USB0. Bidirectional differential data pin (D+ per USB specification) for USB0. PB0 I/O TTL GPIO port B bit 0. CAN1Rx I TTL CAN module 1 receive. I2C5SCL I/O OD I2C module 5 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. T4CCP0 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 0. U1Rx I TTL UART module 1 receive. USB0ID I Analog This signal senses the state of the USB ID signal. The USB PHY enables an integrated pull-up, and an external element (USB connector) indicates the initial state of the USB controller (pulled down is the A side of the cable and pulled up is the B side). June 18, 2014 1781 Texas Instruments-Production Data Signal Tables Table 26-2. Signals by Pin Number (continued) Pin Number 96 97 Pin Name Pin Type PB1 I/O TTL GPIO port B bit 1. CAN1Tx O TTL CAN module 1 transmit. I2C5SDA I/O OD I2C module 5 data. T4CCP1 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 1. U1Tx O TTL UART module 1 transmit. USB0VBUS I/O Analog PC3 I/O TTL GPIO port C bit 3. SWO O TTL JTAG TDO and SWO. TDO O TTL JTAG TDO and SWO. PC2 I/O TTL GPIO port C bit 2. TDI I TTL JTAG TDI. PC1 I/O TTL GPIO port C bit 1. SWDIO I/O TTL JTAG TMS and SWDIO. TMS I TTL JTAG TMS and SWDIO. PC0 I/O TTL GPIO port C bit 0. SWCLK I TTL JTAG/SWD CLK. TCK I TTL JTAG/SWD CLK. VDD - Power PQ4 I/O TTL GPIO port Q bit 4. DIVSCLK O TTL An optionally divided reference clock output based on a selected clock source. Note that this signal is not synchronized to the System Clock. U1Rx I TTL UART module 1 receive. PP2 I/O TTL GPIO port P bit 2. EPI0S29 I/O TTL EPI module 0 signal 29. 98 99 100 101 Buffer Type Description 102 103 This signal is used during the session request protocol. This signal allows the USB PHY to both sense the voltage level of VBUS, and pull up VBUS momentarily during VBUS pulsing. Positive supply for I/O and some logic. U0DTR O TTL UART module 0 Data Terminal Ready modem status input signal. USB0NXT O TTL Asserted by the external PHY to throttle all data types. PP3 I/O TTL GPIO port P bit 3. EPI0S30 I/O TTL EPI module 0 signal 30. RTCCLK O TTL Buffered version of the Hibernation module's 32.768-kHz clock. This signal is not output when the part is in Hibernate mode and before being configured after power-on reset. U0DCD I TTL UART module 0 Data Carrier Detect modem status input signal. U1CTS I TTL UART module 1 Clear To Send modem flow control input signal. USB0DIR O TTL Indicates that the external PHY is able to accept data from the USB controller. PP4 I/O TTL GPIO port P bit 4. U0DSR I TTL UART module 0 Data Set Ready modem output control line. U3RTS O TTL UART module 3 Request to Send modem flow control output line. USB0D7 I/O TTL USB data 7. 104 105 1782 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type Buffer Type Description PP5 I/O TTL GPIO port P bit 5. I2C2SCL I/O OD I2C module 2 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. U3CTS I TTL UART module 3 Clear To Send modem flow control input signal. USB0D6 I/O TTL USB data 6. 106 PN0 I/O TTL GPIO port N bit 0. U1RTS O TTL UART module 1 Request to Send modem flow control output line. 107 PN1 I/O TTL GPIO port N bit 1. U1CTS I TTL UART module 1 Clear To Send modem flow control input signal. PN2 I/O TTL GPIO port N bit 2. EPI0S29 I/O TTL EPI module 0 signal 29. U1DCD I TTL UART module 1 Data Carrier Detect modem status input signal. U2RTS O TTL UART module 2 Request to Send modem flow control output line. 108 109 PN3 I/O TTL GPIO port N bit 3. EPI0S30 I/O TTL EPI module 0 signal 30. U1DSR I TTL UART module 1 Data Set Ready modem output control line. U2CTS I TTL UART module 2 Clear To Send modem flow control input signal. PN4 I/O TTL GPIO port N bit 4. EPI0S34 I/O TTL EPI module 0 signal 34. I2C2SDA I/O OD I2C module 2 data. U1DTR O TTL UART module 1 Data Terminal Ready modem status input signal. U3RTS O TTL UART module 3 Request to Send modem flow control output line. PN5 I/O TTL GPIO port N bit 5. EPI0S35 I/O TTL EPI module 0 signal 35. I2C2SCL I/O OD I2C module 2 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. U1RI I TTL UART module 1 Ring Indicator modem status input signal. U3CTS I TTL UART module 3 Clear To Send modem flow control input signal. 113 VDD - Power Positive supply for I/O and some logic. 114 GND - Power Ground reference for logic and I/O pins. VDDC - Power Positive supply for most of the logic function, including the processor core and most peripherals. The voltage on this pin is 1.2 V and is supplied by the on-chip LDO. The VDDC pins should only be connected to each other and an external capacitor as specified in Table 27-15 on page 1834 . PJ0 I/O TTL GPIO port J bit 0. EN0PPS O TTL Ethernet 0 Pulse-Per-Second (PPS) Output. U3Rx I TTL UART module 3 receive. PJ1 I/O TTL GPIO port J bit 1. U3Tx O TTL UART module 3 transmit. 110 111 112 115 116 117 June 18, 2014 1783 Texas Instruments-Production Data Signal Tables Table 26-2. Signals by Pin Number (continued) Pin Number Pin Name Pin Type PP0 I/O TTL C2+ I Analog SSI3XDAT2 I/O TTL SSI Module 3 Bi-directional Data Pin 2. U6Rx I TTL UART module 6 receive. PP1 I/O TTL GPIO port P bit 1. 118 121 122 123 124 125 126 GPIO port P bit 0. Analog comparator 2 positive input. C2- I Analog SSI3XDAT3 I/O TTL SSI Module 3 Bi-directional Data Pin 3. U6Tx O TTL UART module 6 transmit. GPIO port B bit 5. 119 120 Buffer Type Description Analog comparator 2 negative input. PB5 I/O TTL AIN11 I Analog I2C5SDA I/O OD I2C module 5 data. SSI1Clk I/O TTL SSI module 1 clock. U0RTS O TTL UART module 0 Request to Send modem flow control output signal. GPIO port B bit 4. Analog-to-digital converter input 11. PB4 I/O TTL AIN10 I Analog I2C5SCL I/O OD I2C module 5 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. SSI1Fss I/O TTL SSI module 1 frame signal. UART module 0 Clear To Send modem flow control input signal. U0CTS I TTL VDD - Power Analog-to-digital converter input 10. Positive supply for I/O and some logic. PE4 I/O TTL AIN9 I Analog GPIO port E bit 4. SSI1XDAT0 I/O TTL SSI Module 1 Bi-directional Data Pin 0 (SSI1TX in Legacy SSI Mode). U1RI I TTL UART module 1 Ring Indicator modem status input signal. GPIO port E bit 5. Analog-to-digital converter input 9. PE5 I/O TTL AIN8 I Analog SSI1XDAT1 I/O TTL SSI Module 1 Bi-directional Data Pin 1 (SSI1RX in Legacy SSI Mode). PD4 I/O TTL GPIO port D bit 4. Analog-to-digital converter input 8. AIN7 I Analog SSI1XDAT2 I/O TTL Analog-to-digital converter input 7. SSI Module 1 Bi-directional Data Pin 2. T3CCP0 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 0. U2Rx I TTL UART module 2 receive. PD5 I/O TTL GPIO port D bit 5. AIN6 I Analog SSI1XDAT3 I/O TTL Analog-to-digital converter input 6. SSI Module 1 Bi-directional Data Pin 3. T3CCP1 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 1. U2Tx O TTL UART module 2 transmit. 1784 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-2. Signals by Pin Number (continued) Pin Number 127 128 26.2 Pin Name Pin Type Buffer Type Description PD6 I/O TTL AIN5 I Analog GPIO port D bit 6. SSI2XDAT3 I/O TTL SSI Module 2 Bi-directional Data Pin 3. T4CCP0 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 0. U2RTS O TTL UART module 2 Request to Send modem flow control output line. USB0EPEN O TTL Optionally used in Host mode to control an external power source to supply power to the USB bus. GPIO port D bit 7. Analog-to-digital converter input 5. PD7 I/O TTL AIN4 I Analog NMI I TTL Non-maskable interrupt. SSI2XDAT2 I/O TTL SSI Module 2 Bi-directional Data Pin 2. T4CCP1 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 1. U2CTS I TTL UART module 2 Clear To Send modem flow control input signal. USB0PFLT I TTL Optionally used in Host mode by an external power source to indicate an error state by that power source. Analog-to-digital converter input 4. Signals by Signal Name Table 26-3. Signals by Signal Name Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description AIN0 12 PE3 I Analog Analog-to-digital converter input 0. AIN1 13 PE2 I Analog Analog-to-digital converter input 1. AIN2 14 PE1 I Analog Analog-to-digital converter input 2. AIN3 15 PE0 I Analog Analog-to-digital converter input 3. AIN4 128 PD7 I Analog Analog-to-digital converter input 4. AIN5 127 PD6 I Analog Analog-to-digital converter input 5. AIN6 126 PD5 I Analog Analog-to-digital converter input 6. AIN7 125 PD4 I Analog Analog-to-digital converter input 7. AIN8 124 PE5 I Analog Analog-to-digital converter input 8. AIN9 123 PE4 I Analog Analog-to-digital converter input 9. AIN10 121 PB4 I Analog Analog-to-digital converter input 10. AIN11 120 PB5 I Analog Analog-to-digital converter input 11. AIN12 4 PD3 I Analog Analog-to-digital converter input 12. AIN13 3 PD2 I Analog Analog-to-digital converter input 13. AIN14 2 PD1 I Analog Analog-to-digital converter input 14. AIN15 1 PD0 I Analog Analog-to-digital converter input 15. AIN16 18 PK0 I Analog Analog-to-digital converter input 16. AIN17 19 PK1 I Analog Analog-to-digital converter input 17. AIN18 20 PK2 I Analog Analog-to-digital converter input 18. AIN19 21 PK3 I Analog Analog-to-digital converter input 19. C0+ 23 PC6 I Analog Analog comparator 0 positive input. June 18, 2014 1785 Texas Instruments-Production Data Signal Tables Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description C0- 22 PC7 I Analog Analog comparator 0 negative input. C0o 1 83 PD0 (5) PL2 (5) O TTL C1+ 24 PC5 I Analog Analog comparator 1 positive input. C1- 25 PC4 I Analog Analog comparator 1 negative input. C1o 2 84 PD1 (5) PL3 (5) O TTL C2+ 118 PP0 I Analog Analog comparator 2 positive input. Analog comparator 2 negative input. Analog comparator 0 output. Analog comparator 1 output. C2- 119 PP1 I Analog C2o 3 PD2 (5) O TTL Analog comparator 2 output. CAN0Rx 33 PA0 (7) I TTL CAN module 0 receive. CAN0Tx 34 PA1 (7) O TTL CAN module 0 transmit. CAN1Rx 95 PB0 (7) I TTL CAN module 1 receive. CAN1Tx 96 PB1 (7) O TTL CAN module 1 transmit. DIVSCLK 102 PQ4 (7) O TTL An optionally divided reference clock output based on a selected clock source. Note that this signal is not synchronized to the System Clock. EN0LED0 42 63 PF0 (5) PK4 (5) O TTL Ethernet 0 LED 0. EN0LED1 46 61 PF4 (5) PK6 (5) O TTL Ethernet 0 LED 1. EN0LED2 43 62 PF1 (5) PK5 (5) O TTL Ethernet 0 LED 2. EN0PPS 49 116 PG0 (5) PJ0 (5) O TTL Ethernet 0 Pulse-Per-Second (PPS) Output. EN0RXIN 53 fixed I/O TTL Ethernet PHY negative receive differential input. EN0RXIP 54 fixed I/O TTL Ethernet PHY positive receive differential input. EN0TXON 56 fixed I/O TTL Ethernet PHY negative transmit differential output. EN0TXOP 57 fixed I/O TTL Ethernet PHY positive transmit differential output. EPI0S0 18 29 PK0 (15) PH0 (15) I/O TTL EPI module 0 signal 0. EPI0S1 19 30 PK1 (15) PH1 (15) I/O TTL EPI module 0 signal 1. EPI0S2 20 31 PK2 (15) PH2 (15) I/O TTL EPI module 0 signal 2. EPI0S3 21 32 PK3 (15) PH3 (15) I/O TTL EPI module 0 signal 3. EPI0S4 22 PC7 (15) I/O TTL EPI module 0 signal 4. EPI0S5 23 PC6 (15) I/O TTL EPI module 0 signal 5. EPI0S6 24 PC5 (15) I/O TTL EPI module 0 signal 6. EPI0S7 25 PC4 (15) I/O TTL EPI module 0 signal 7. EPI0S8 40 PA6 (15) I/O TTL EPI module 0 signal 8. EPI0S9 41 PA7 (15) I/O TTL EPI module 0 signal 9. EPI0S10 50 PG1 (15) I/O TTL EPI module 0 signal 10. 1786 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-3. Signals by Signal Name (continued) Pin Name EPI0S11 Pin Number Pin Mux / Pin Assignment 49 PG0 (15) Pin Type I/O Buffer Type Description TTL EPI module 0 signal 11. EPI0S12 75 PM3 (15) I/O TTL EPI module 0 signal 12. EPI0S13 76 PM2 (15) I/O TTL EPI module 0 signal 13. EPI0S14 77 PM1 (15) I/O TTL EPI module 0 signal 14. EPI0S15 78 PM0 (15) I/O TTL EPI module 0 signal 15. EPI0S16 81 PL0 (15) I/O TTL EPI module 0 signal 16. EPI0S17 82 PL1 (15) I/O TTL EPI module 0 signal 17. EPI0S18 83 PL2 (15) I/O TTL EPI module 0 signal 18. EPI0S19 84 PL3 (15) I/O TTL EPI module 0 signal 19. EPI0S20 5 PQ0 (15) I/O TTL EPI module 0 signal 20. EPI0S21 6 PQ1 (15) I/O TTL EPI module 0 signal 21. EPI0S22 11 PQ2 (15) I/O TTL EPI module 0 signal 22. EPI0S23 27 PQ3 (15) I/O TTL EPI module 0 signal 23. EPI0S24 60 PK7 (15) I/O TTL EPI module 0 signal 24. EPI0S25 61 PK6 (15) I/O TTL EPI module 0 signal 25. EPI0S26 85 PL4 (15) I/O TTL EPI module 0 signal 26. EPI0S27 91 PB2 (15) I/O TTL EPI module 0 signal 27. EPI0S28 92 PB3 (15) I/O TTL EPI module 0 signal 28. EPI0S29 103 109 PP2 (15) PN2 (15) I/O TTL EPI module 0 signal 29. EPI0S30 104 110 PP3 (15) PN3 (15) I/O TTL EPI module 0 signal 30. EPI0S31 62 PK5 (15) I/O TTL EPI module 0 signal 31. EPI0S32 63 PK4 (15) I/O TTL EPI module 0 signal 32. EPI0S33 86 PL5 (15) I/O TTL EPI module 0 signal 33. EPI0S34 111 PN4 (15) I/O TTL EPI module 0 signal 34. EPI0S35 112 PN5 (15) I/O TTL EPI module 0 signal 35. GND 17 48 55 58 80 114 fixed - Power Ground reference for logic and I/O pins. GNDA 10 fixed - Power The ground reference for the analog circuits (ADC, Analog Comparators, etc.). These are separated from GND to minimize the electrical noise contained on VDD from affecting the analog functions. HIB 65 fixed O TTL An output that indicates the processor is in Hibernate mode. I2C0SCL 91 PB2 (2) I/O OD I2C module 0 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C0SDA 92 PB3 (2) I/O OD I2C module 0 data. June 18, 2014 1787 Texas Instruments-Production Data Signal Tables Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description I2C1SCL 49 PG0 (2) I/O OD I2C module 1 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C1SDA 50 PG1 (2) I/O OD I2C module 1 data. I2C2SCL 82 106 112 PL1 (2) PP5 (2) PN5 (3) I/O OD I2C module 2 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C2SDA 81 111 PL0 (2) PN4 (3) I/O OD I2C module 2 data. I2C3SCL 63 PK4 (2) I/O OD I2C module 3 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C3SDA 62 PK5 (2) I/O OD I2C module 3 data. I2C4SCL 61 PK6 (2) I/O OD I2C module 4 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C4SDA 60 PK7 (2) I/O OD I2C module 4 data. I2C5SCL 95 121 PB0 (2) PB4 (2) I/O OD I2C module 5 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C5SDA 96 120 PB1 (2) PB5 (2) I/O OD I2C module 5 data. I2C6SCL 40 PA6 (2) I/O OD I2C module 6 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C6SDA 41 PA7 (2) I/O OD I2C module 6 data. I2C7SCL 1 37 PD0 (2) PA4 (2) I/O OD I2C module 7 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C7SDA 2 38 PD1 (2) PA5 (2) I/O OD I2C module 7 data. I2C8SCL 3 35 PD2 (2) PA2 (2) I/O OD I2C module 8 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C8SDA 4 36 PD3 (2) PA3 (2) I/O OD I2C module 8 data. I2C9SCL 33 PA0 (2) I/O OD I2C module 9 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C9SDA 34 PA1 (2) I/O OD I2C module 9 data. IDX0 84 PL3 (6) I TTL QEI module 0 index. M0FAULT0 46 PF4 (6) I TTL Motion Control Module 0 PWM Fault 0. M0FAULT1 61 PK6 (6) I TTL Motion Control Module 0 PWM Fault 1. M0FAULT2 60 PK7 (6) I TTL Motion Control Module 0 PWM Fault 2. M0FAULT3 81 PL0 (6) I TTL Motion Control Module 0 PWM Fault 3. M0PWM0 42 PF0 (6) O TTL Motion Control Module 0 PWM 0. This signal is controlled by Module 0 PWM Generator 0. 1788 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description M0PWM1 43 PF1 (6) O TTL Motion Control Module 0 PWM 1. This signal is controlled by Module 0 PWM Generator 0. M0PWM2 44 PF2 (6) O TTL Motion Control Module 0 PWM 2. This signal is controlled by Module 0 PWM Generator 1. M0PWM3 45 PF3 (6) O TTL Motion Control Module 0 PWM 3. This signal is controlled by Module 0 PWM Generator 1. M0PWM4 49 PG0 (6) O TTL Motion Control Module 0 PWM 4. This signal is controlled by Module 0 PWM Generator 2. M0PWM5 50 PG1 (6) O TTL Motion Control Module 0 PWM 5. This signal is controlled by Module 0 PWM Generator 2. M0PWM6 63 PK4 (6) O TTL Motion Control Module 0 PWM 6. This signal is controlled by Module 0 PWM Generator 3. M0PWM7 62 PK5 (6) O TTL Motion Control Module 0 PWM 7. This signal is controlled by Module 0 PWM Generator 3. Non-maskable interrupt. NMI 128 PD7 (8) I TTL OSC0 88 fixed I Analog Main oscillator crystal input or an external clock reference input. OSC1 89 fixed O Analog Main oscillator crystal output. Leave unconnected when using a single-ended clock source. PA0 33 - I/O TTL GPIO port A bit 0. PA1 34 - I/O TTL GPIO port A bit 1. PA2 35 - I/O TTL GPIO port A bit 2. PA3 36 - I/O TTL GPIO port A bit 3. PA4 37 - I/O TTL GPIO port A bit 4. PA5 38 - I/O TTL GPIO port A bit 5. PA6 40 - I/O TTL GPIO port A bit 6. PA7 41 - I/O TTL GPIO port A bit 7. PB0 95 - I/O TTL GPIO port B bit 0. PB1 96 - I/O TTL GPIO port B bit 1. PB2 91 - I/O TTL GPIO port B bit 2. PB3 92 - I/O TTL GPIO port B bit 3. PB4 121 - I/O TTL GPIO port B bit 4. PB5 120 - I/O TTL GPIO port B bit 5. PC0 100 - I/O TTL GPIO port C bit 0. PC1 99 - I/O TTL GPIO port C bit 1. PC2 98 - I/O TTL GPIO port C bit 2. PC3 97 - I/O TTL GPIO port C bit 3. PC4 25 - I/O TTL GPIO port C bit 4. PC5 24 - I/O TTL GPIO port C bit 5. PC6 23 - I/O TTL GPIO port C bit 6. PC7 22 - I/O TTL GPIO port C bit 7. PD0 1 - I/O TTL GPIO port D bit 0. PD1 2 - I/O TTL GPIO port D bit 1. June 18, 2014 1789 Texas Instruments-Production Data Signal Tables Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description 3 - I/O TTL GPIO port D bit 2. PD3 4 - I/O TTL GPIO port D bit 3. PD4 125 - I/O TTL GPIO port D bit 4. PD5 126 - I/O TTL GPIO port D bit 5. PD6 127 - I/O TTL GPIO port D bit 6. PD7 128 - I/O TTL GPIO port D bit 7. PD2 PE0 15 - I/O TTL GPIO port E bit 0. PE1 14 - I/O TTL GPIO port E bit 1. PE2 13 - I/O TTL GPIO port E bit 2. PE3 12 - I/O TTL GPIO port E bit 3. PE4 123 - I/O TTL GPIO port E bit 4. PE5 124 - I/O TTL GPIO port E bit 5. PF0 42 - I/O TTL GPIO port F bit 0. PF1 43 - I/O TTL GPIO port F bit 1. PF2 44 - I/O TTL GPIO port F bit 2. PF3 45 - I/O TTL GPIO port F bit 3. PF4 46 - I/O TTL GPIO port F bit 4. PG0 49 - I/O TTL GPIO port G bit 0. PG1 50 - I/O TTL GPIO port G bit 1. PH0 29 - I/O TTL GPIO port H bit 0. PH1 30 - I/O TTL GPIO port H bit 1. PH2 31 - I/O TTL GPIO port H bit 2. PH3 32 - I/O TTL GPIO port H bit 3. PhA0 82 PL1 (6) I TTL QEI module 0 phase A. PhB0 83 PL2 (6) I TTL QEI module 0 phase B. PJ0 116 - I/O TTL GPIO port J bit 0. PJ1 117 - I/O TTL GPIO port J bit 1. PK0 18 - I/O TTL GPIO port K bit 0. PK1 19 - I/O TTL GPIO port K bit 1. PK2 20 - I/O TTL GPIO port K bit 2. PK3 21 - I/O TTL GPIO port K bit 3. PK4 63 - I/O TTL GPIO port K bit 4. PK5 62 - I/O TTL GPIO port K bit 5. PK6 61 - I/O TTL GPIO port K bit 6. PK7 60 - I/O TTL GPIO port K bit 7. PL0 81 - I/O TTL GPIO port L bit 0. PL1 82 - I/O TTL GPIO port L bit 1. PL2 83 - I/O TTL GPIO port L bit 2. PL3 84 - I/O TTL GPIO port L bit 3. PL4 85 - I/O TTL GPIO port L bit 4. PL5 86 - I/O TTL GPIO port L bit 5. 1790 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-3. Signals by Signal Name (continued) Pin Name PL6 Pin Number Pin Mux / Pin Assignment 94 - Pin Type I/O Buffer Type Description TTL GPIO port L bit 6. PL7 93 - I/O TTL GPIO port L bit 7. PM0 78 - I/O TTL GPIO port M bit 0. PM1 77 - I/O TTL GPIO port M bit 1. PM2 76 - I/O TTL GPIO port M bit 2. PM3 75 - I/O TTL GPIO port M bit 3. PM4 74 - I/O TTL GPIO port M bit 4. PM5 73 - I/O TTL GPIO port M bit 5. PM6 72 - I/O TTL GPIO port M bit 6. PM7 71 - I/O TTL GPIO port M bit 7. PN0 107 - I/O TTL GPIO port N bit 0. PN1 108 - I/O TTL GPIO port N bit 1. PN2 109 - I/O TTL GPIO port N bit 2. PN3 110 - I/O TTL GPIO port N bit 3. PN4 111 - I/O TTL GPIO port N bit 4. PN5 112 - I/O TTL GPIO port N bit 5. PP0 118 - I/O TTL GPIO port P bit 0. PP1 119 - I/O TTL GPIO port P bit 1. PP2 103 - I/O TTL GPIO port P bit 2. PP3 104 - I/O TTL GPIO port P bit 3. PP4 105 - I/O TTL GPIO port P bit 4. PP5 106 - I/O TTL GPIO port P bit 5. PQ0 5 - I/O TTL GPIO port Q bit 0. PQ1 6 - I/O TTL GPIO port Q bit 1. PQ2 11 - I/O TTL GPIO port Q bit 2. PQ3 27 - I/O TTL GPIO port Q bit 3. PQ4 102 - I/O TTL GPIO port Q bit 4. RBIAS 59 fixed O Analog RST 70 fixed I TTL System reset input. RTCCLK 24 60 104 PC5 (7) PK7 (5) PP3 (7) O TTL Buffered version of the Hibernation module's 32.768-kHz clock. This signal is not output when the part is in Hibernate mode and before being configured after power-on reset. 4.87-kΩ resistor (1% precision) for Ethernet PHY. SSI0Clk 35 PA2 (15) I/O TTL SSI module 0 clock SSI0Fss 36 PA3 (15) I/O TTL SSI module 0 frame signal SSI0XDAT0 37 PA4 (15) I/O TTL SSI Module 0 Bi-directional Data Pin 0 (SSI0TX in Legacy SSI Mode). SSI0XDAT1 38 PA5 (15) I/O TTL SSI Module 0 Bi-directional Data Pin 1 (SSI0RX in Legacy SSI Mode). SSI0XDAT2 40 PA6 (13) I/O TTL SSI Module 0 Bi-directional Data Pin 2. SSI0XDAT3 41 PA7 (13) I/O TTL SSI Module 0 Bi-directional Data Pin 3. SSI1Clk 120 PB5 (15) I/O TTL SSI module 1 clock. June 18, 2014 1791 Texas Instruments-Production Data Signal Tables Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description SSI1Fss 121 PB4 (15) I/O TTL SSI module 1 frame signal. SSI1XDAT0 123 PE4 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 0 (SSI1TX in Legacy SSI Mode). SSI1XDAT1 124 PE5 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 1 (SSI1RX in Legacy SSI Mode). SSI1XDAT2 125 PD4 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 2. SSI1XDAT3 126 PD5 (15) I/O TTL SSI Module 1 Bi-directional Data Pin 3. SSI2Clk 4 PD3 (15) I/O TTL SSI module 2 clock. SSI2Fss 3 PD2 (15) I/O TTL SSI module 2 frame signal. SSI2XDAT0 2 PD1 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 0 (SSI2TX in Legacy SSI Mode). SSI2XDAT1 1 PD0 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 1 (SSI2RX in Legacy SSI Mode). SSI2XDAT2 128 PD7 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 2. SSI2XDAT3 127 PD6 (15) I/O TTL SSI Module 2 Bi-directional Data Pin 3. SSI3Clk 5 45 PQ0 (14) PF3 (14) I/O TTL SSI module 3 clock. SSI3Fss 6 44 PQ1 (14) PF2 (14) I/O TTL SSI module 3 frame signal. SSI3XDAT0 11 43 PQ2 (14) PF1 (14) I/O TTL SSI Module 3 Bi-directional Data Pin 0 (SSI3TX in Legacy SSI Mode). SSI3XDAT1 27 42 PQ3 (14) PF0 (14) I/O TTL SSI Module 3 Bi-directional Data Pin 1 (SSI3RX in Legacy SSI Mode). SSI3XDAT2 46 118 PF4 (14) PP0 (15) I/O TTL SSI Module 3 Bi-directional Data Pin 2. SSI3XDAT3 119 PP1 (15) I/O TTL SSI Module 3 Bi-directional Data Pin 3. SWCLK 100 PC0 (1) I TTL JTAG/SWD CLK. SWDIO 99 PC1 (1) I/O TTL JTAG TMS and SWDIO. SWO 97 PC3 (1) O TTL JTAG TDO and SWO. T0CCP0 1 33 85 PD0 (3) PA0 (3) PL4 (3) I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 0. T0CCP1 2 34 86 PD1 (3) PA1 (3) PL5 (3) I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 1. T1CCP0 3 35 94 PD2 (3) PA2 (3) PL6 (3) I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 0. T1CCP1 4 36 93 PD3 (3) PA3 (3) PL7 (3) I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 1. T2CCP0 37 78 PA4 (3) PM0 (3) I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 0. T2CCP1 38 77 PA5 (3) PM1 (3) I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 1. 1792 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description T3CCP0 40 76 125 PA6 (3) PM2 (3) PD4 (3) I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 0. T3CCP1 41 75 126 PA7 (3) PM3 (3) PD5 (3) I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 1. T4CCP0 74 95 127 PM4 (3) PB0 (3) PD6 (3) I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 0. T4CCP1 73 96 128 PM5 (3) PB1 (3) PD7 (3) I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 1. T5CCP0 72 91 PM6 (3) PB2 (3) I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 0. T5CCP1 71 92 PM7 (3) PB3 (3) I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 1. TCK 100 PC0 (1) I TTL JTAG/SWD CLK. TDI 98 PC2 (1) I TTL JTAG TDI. TDO 97 PC3 (1) O TTL JTAG TDO and SWO. TMPR0 71 PM7 I/O TTL Tamper signal 0. TMPR1 72 PM6 I/O TTL Tamper signal 1. TMPR2 73 PM5 I/O TTL Tamper signal 2. TMPR3 74 PM4 I/O TTL Tamper signal 3. TMS 99 PC1 (1) I TTL JTAG TMS and SWDIO. TRCLK 45 PF3 (15) O TTL Trace clock. TRD0 44 PF2 (15) O TTL Trace data 0. TRD1 43 PF1 (15) O TTL Trace data 1. TRD2 42 PF0 (15) O TTL Trace data 2. TRD3 46 PF4 (15) O TTL Trace data 3. U0CTS 30 74 121 PH1 (1) PM4 (1) PB4 (1) I TTL UART module 0 Clear To Send modem flow control input signal. U0DCD 31 73 104 PH2 (1) PM5 (1) PP3 (2) I TTL UART module 0 Data Carrier Detect modem status input signal. U0DSR 32 72 105 PH3 (1) PM6 (1) PP4 (2) I TTL UART module 0 Data Set Ready modem output control line. U0DTR 103 PP2 (1) O TTL UART module 0 Data Terminal Ready modem status input signal. U0RI 60 71 PK7 (1) PM7 (1) I TTL UART module 0 Ring Indicator modem status input signal. U0RTS 29 120 PH0 (1) PB5 (1) O TTL UART module 0 Request to Send modem flow control output signal. U0Rx 33 PA0 (1) I TTL UART module 0 receive. U0Tx 34 PA1 (1) O TTL UART module 0 transmit. June 18, 2014 1793 Texas Instruments-Production Data Signal Tables Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description U1CTS 104 108 PP3 (1) PN1 (1) I TTL UART module 1 Clear To Send modem flow control input signal. U1DCD 13 109 PE2 (1) PN2 (1) I TTL UART module 1 Data Carrier Detect modem status input signal. U1DSR 14 110 PE1 (1) PN3 (1) I TTL UART module 1 Data Set Ready modem output control line. U1DTR 12 111 PE3 (1) PN4 (1) O TTL UART module 1 Data Terminal Ready modem status input signal. U1RI 112 123 PN5 (1) PE4 (1) I TTL UART module 1 Ring Indicator modem status input signal. U1RTS 15 107 PE0 (1) PN0 (1) O TTL UART module 1 Request to Send modem flow control output line. U1Rx 95 102 PB0 (1) PQ4 (1) I TTL UART module 1 receive. U1Tx 96 PB1 (1) O TTL UART module 1 transmit. U2CTS 110 128 PN3 (2) PD7 (1) I TTL UART module 2 Clear To Send modem flow control input signal. U2RTS 109 127 PN2 (2) PD6 (1) O TTL UART module 2 Request to Send modem flow control output line. U2Rx 40 125 PA6 (1) PD4 (1) I TTL UART module 2 receive. U2Tx 41 126 PA7 (1) PD5 (1) O TTL UART module 2 transmit. U3CTS 106 112 PP5 (1) PN5 (2) I TTL UART module 3 Clear To Send modem flow control input signal. U3RTS 105 111 PP4 (1) PN4 (2) O TTL UART module 3 Request to Send modem flow control output line. U3Rx 37 116 PA4 (1) PJ0 (1) I TTL UART module 3 receive. U3Tx 38 117 PA5 (1) PJ1 (1) O TTL UART module 3 transmit. U4CTS 21 PK3 (1) I TTL UART module 4 Clear To Send modem flow control input signal. U4RTS 20 PK2 (1) O TTL UART module 4 Request to Send modem flow control output line. U4Rx 18 35 PK0 (1) PA2 (1) I TTL UART module 4 receive. U4Tx 19 36 PK1 (1) PA3 (1) O TTL UART module 4 transmit. U5Rx 23 PC6 (1) I TTL UART module 5 receive. U5Tx 22 PC7 (1) O TTL UART module 5 transmit. U6Rx 118 PP0 (1) I TTL UART module 6 receive. U6Tx 119 PP1 (1) O TTL UART module 6 transmit. U7Rx 25 PC4 (1) I TTL UART module 7 receive. U7Tx 24 PC5 (1) O TTL UART module 7 transmit. USB0CLK 92 PB3 (14) O TTL 60-MHz clock to the external PHY. USB0D0 81 PL0 (14) I/O TTL USB data 0. 1794 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description USB0D1 82 PL1 (14) I/O TTL USB data 1. USB0D2 83 PL2 (14) I/O TTL USB data 2. USB0D3 84 PL3 (14) I/O TTL USB data 3. USB0D4 85 PL4 (14) I/O TTL USB data 4. USB0D5 86 PL5 (14) I/O TTL USB data 5. USB0D6 106 PP5 (14) I/O TTL USB data 6. USB0D7 105 PP4 (14) I/O TTL USB data 7. USB0DIR 104 PP3 (14) O TTL Indicates that the external PHY is able to accept data from the USB controller. USB0DM 93 PL7 I/O Analog Bidirectional differential data pin (D- per USB specification) for USB0. USB0DP 94 PL6 I/O Analog Bidirectional differential data pin (D+ per USB specification) for USB0. USB0EPEN 40 41 127 PA6 (5) PA7 (11) PD6 (5) O TTL Optionally used in Host mode to control an external power source to supply power to the USB bus. USB0ID 95 PB0 I Analog This signal senses the state of the USB ID signal. The USB PHY enables an integrated pull-up, and an external element (USB connector) indicates the initial state of the USB controller (pulled down is the A side of the cable and pulled up is the B side). USB0NXT 103 PP2 (14) O TTL Asserted by the external PHY to throttle all data types. USB0PFLT 41 128 PA7 (5) PD7 (5) I TTL Optionally used in Host mode by an external power source to indicate an error state by that power source. USB0STP 91 PB2 (14) O TTL Asserted by the USB controller to signal the end of a USB transmit packet or register write operation. USB0VBUS 96 PB1 I/O Analog This signal is used during the session request protocol. This signal allows the USB PHY to both sense the voltage level of VBUS, and pull up VBUS momentarily during VBUS pulsing. VBAT 68 fixed - Power Power source for the Hibernation module. It is normally connected to the positive terminal of a battery and serves as the battery backup/Hibernation module power-source supply. VDD 7 16 26 28 39 47 51 52 69 79 90 101 113 122 fixed - Power Positive supply for I/O and some logic. June 18, 2014 1795 Texas Instruments-Production Data Signal Tables Table 26-3. Signals by Signal Name (continued) Pin Name Pin Number Pin Mux / Pin Assignment Pin Type Buffer Type Description VDDA 8 fixed - Power The positive supply for the analog circuits (ADC, Analog Comparators, etc.). These are separated from VDD to minimize the electrical noise contained on VDD from affecting the analog functions. VDDA pins must be supplied with a voltage that meets the specification in , regardless of system implementation. VDDC 87 115 fixed - Power Positive supply for most of the logic function, including the processor core and most peripherals. The voltage on this pin is 1.2 V and is supplied by the on-chip LDO. The VDDC pins should only be connected to each other and an external capacitor as specified in Table 27-15 on page 1834 . VREFA+ 9 fixed - Analog A reference voltage used to specify the voltage at which the ADC converts to a maximum value. This pin is used in conjunction with GNDA. The voltage that is applied to VREFA+ is the voltage with which an AINn signal is converted to 4095. The VREFA+ voltage is limited to the range specified in Table 27-44 on page 1861. WAKE 64 fixed I TTL An external input that brings the processor out of Hibernate mode when asserted. XOSC0 66 fixed I Analog Hibernation module oscillator crystal input or an external clock reference input. Note that this is either a crystal or a 32.768-kHz oscillator for the Hibernation module RTC. XOSC1 67 fixed O Analog Hibernation module oscillator crystal output. Leave unconnected when using a single-ended clock source. 1796 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 26.3 Signals by Function, Except for GPIO Table 26-4. Signals by Function, Except for GPIO Function ADC Analog Comparators Controller Area Network Pin Name Pin Number Pin Type Buffer Type Description AIN0 12 I Analog Analog-to-digital converter input 0. AIN1 13 I Analog Analog-to-digital converter input 1. AIN2 14 I Analog Analog-to-digital converter input 2. AIN3 15 I Analog Analog-to-digital converter input 3. AIN4 128 I Analog Analog-to-digital converter input 4. AIN5 127 I Analog Analog-to-digital converter input 5. AIN6 126 I Analog Analog-to-digital converter input 6. AIN7 125 I Analog Analog-to-digital converter input 7. AIN8 124 I Analog Analog-to-digital converter input 8. AIN9 123 I Analog Analog-to-digital converter input 9. AIN10 121 I Analog Analog-to-digital converter input 10. AIN11 120 I Analog Analog-to-digital converter input 11. AIN12 4 I Analog Analog-to-digital converter input 12. AIN13 3 I Analog Analog-to-digital converter input 13. AIN14 2 I Analog Analog-to-digital converter input 14. AIN15 1 I Analog Analog-to-digital converter input 15. AIN16 18 I Analog Analog-to-digital converter input 16. AIN17 19 I Analog Analog-to-digital converter input 17. AIN18 20 I Analog Analog-to-digital converter input 18. AIN19 21 I Analog Analog-to-digital converter input 19. VREFA+ 9 - Analog A reference voltage used to specify the voltage at which the ADC converts to a maximum value. This pin is used in conjunction with GNDA. The voltage that is applied to VREFA+ is the voltage with which an AINn signal is converted to 4095. The VREFA+ voltage is limited to the range specified in Table 27-44 on page 1861. C0+ 23 I Analog Analog comparator 0 positive input. C0- 22 I Analog Analog comparator 0 negative input. C0o 1 83 O TTL C1+ 24 I Analog Analog comparator 1 positive input. C1- 25 I Analog Analog comparator 1 negative input. C1o 2 84 O TTL C2+ 118 I Analog Analog comparator 2 positive input. C2- 119 I Analog Analog comparator 2 negative input. C2o 3 O TTL Analog comparator 2 output. CAN0Rx 33 I TTL CAN module 0 receive. CAN0Tx 34 O TTL CAN module 0 transmit. CAN1Rx 95 I TTL CAN module 1 receive. CAN1Tx 96 O TTL CAN module 1 transmit. Analog comparator 0 output. Analog comparator 1 output. June 18, 2014 1797 Texas Instruments-Production Data Signal Tables Table 26-4. Signals by Function, Except for GPIO (continued) Function Core Ethernet Pin Name Pin Number Pin Type Buffer Type Description TRCLK 45 O TTL Trace clock. TRD0 44 O TTL Trace data 0. TRD1 43 O TTL Trace data 1. TRD2 42 O TTL Trace data 2. TRD3 46 O TTL Trace data 3. EN0LED0 42 63 O TTL Ethernet 0 LED 0. EN0LED1 46 61 O TTL Ethernet 0 LED 1. EN0LED2 43 62 O TTL Ethernet 0 LED 2. EN0PPS 49 116 O TTL Ethernet 0 Pulse-Per-Second (PPS) Output. EN0RXIN 53 I/O TTL Ethernet PHY negative receive differential input. EN0RXIP 54 I/O TTL Ethernet PHY positive receive differential input. EN0TXON 56 I/O TTL Ethernet PHY negative transmit differential output. EN0TXOP 57 I/O TTL Ethernet PHY positive transmit differential output. RBIAS 59 O Analog 4.87-kΩ resistor (1% precision) for Ethernet PHY. 1798 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-4. Signals by Function, Except for GPIO (continued) Function External Peripheral Interface Pin Name Pin Number Pin Type Buffer Type Description EPI0S0 18 29 I/O TTL EPI module 0 signal 0. EPI0S1 19 30 I/O TTL EPI module 0 signal 1. EPI0S2 20 31 I/O TTL EPI module 0 signal 2. EPI0S3 21 32 I/O TTL EPI module 0 signal 3. EPI0S4 22 I/O TTL EPI module 0 signal 4. EPI0S5 23 I/O TTL EPI module 0 signal 5. EPI0S6 24 I/O TTL EPI module 0 signal 6. EPI0S7 25 I/O TTL EPI module 0 signal 7. EPI0S8 40 I/O TTL EPI module 0 signal 8. EPI0S9 41 I/O TTL EPI module 0 signal 9. EPI0S10 50 I/O TTL EPI module 0 signal 10. EPI0S11 49 I/O TTL EPI module 0 signal 11. EPI0S12 75 I/O TTL EPI module 0 signal 12. EPI0S13 76 I/O TTL EPI module 0 signal 13. EPI0S14 77 I/O TTL EPI module 0 signal 14. EPI0S15 78 I/O TTL EPI module 0 signal 15. EPI0S16 81 I/O TTL EPI module 0 signal 16. EPI0S17 82 I/O TTL EPI module 0 signal 17. EPI0S18 83 I/O TTL EPI module 0 signal 18. EPI0S19 84 I/O TTL EPI module 0 signal 19. EPI0S20 5 I/O TTL EPI module 0 signal 20. EPI0S21 6 I/O TTL EPI module 0 signal 21. EPI0S22 11 I/O TTL EPI module 0 signal 22. EPI0S23 27 I/O TTL EPI module 0 signal 23. EPI0S24 60 I/O TTL EPI module 0 signal 24. EPI0S25 61 I/O TTL EPI module 0 signal 25. EPI0S26 85 I/O TTL EPI module 0 signal 26. EPI0S27 91 I/O TTL EPI module 0 signal 27. EPI0S28 92 I/O TTL EPI module 0 signal 28. EPI0S29 103 109 I/O TTL EPI module 0 signal 29. EPI0S30 104 110 I/O TTL EPI module 0 signal 30. EPI0S31 62 I/O TTL EPI module 0 signal 31. EPI0S32 63 I/O TTL EPI module 0 signal 32. EPI0S33 86 I/O TTL EPI module 0 signal 33. EPI0S34 111 I/O TTL EPI module 0 signal 34. EPI0S35 112 I/O TTL EPI module 0 signal 35. June 18, 2014 1799 Texas Instruments-Production Data Signal Tables Table 26-4. Signals by Function, Except for GPIO (continued) Function General-Purpose Timers Pin Name Pin Number Pin Type Buffer Type Description T0CCP0 1 33 85 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 0. T0CCP1 2 34 86 I/O TTL 16/32-Bit Timer 0 Capture/Compare/PWM 1. T1CCP0 3 35 94 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 0. T1CCP1 4 36 93 I/O TTL 16/32-Bit Timer 1 Capture/Compare/PWM 1. T2CCP0 37 78 I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 0. T2CCP1 38 77 I/O TTL 16/32-Bit Timer 2 Capture/Compare/PWM 1. T3CCP0 40 76 125 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 0. T3CCP1 41 75 126 I/O TTL 16/32-Bit Timer 3 Capture/Compare/PWM 1. T4CCP0 74 95 127 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 0. T4CCP1 73 96 128 I/O TTL 16/32-Bit Timer 4 Capture/Compare/PWM 1. T5CCP0 72 91 I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 0. T5CCP1 71 92 I/O TTL 16/32-Bit Timer 5 Capture/Compare/PWM 1. 1800 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-4. Signals by Function, Except for GPIO (continued) Function Hibernate Pin Name Pin Number Pin Type Buffer Type Description HIB 65 O TTL An output that indicates the processor is in Hibernate mode. RTCCLK 24 60 104 O TTL Buffered version of the Hibernation module's 32.768-kHz clock. This signal is not output when the part is in Hibernate mode and before being configured after power-on reset. TMPR0 71 I/O TTL Tamper signal 0. TMPR1 72 I/O TTL Tamper signal 1. TMPR2 73 I/O TTL Tamper signal 2. Tamper signal 3. TMPR3 74 I/O TTL VBAT 68 - Power Power source for the Hibernation module. It is normally connected to the positive terminal of a battery and serves as the battery backup/Hibernation module power-source supply. WAKE 64 I TTL An external input that brings the processor out of Hibernate mode when asserted. XOSC0 66 I Analog Hibernation module oscillator crystal input or an external clock reference input. Note that this is either a crystal or a 32.768-kHz oscillator for the Hibernation module RTC. XOSC1 67 O Analog Hibernation module oscillator crystal output. Leave unconnected when using a single-ended clock source. June 18, 2014 1801 Texas Instruments-Production Data Signal Tables Table 26-4. Signals by Function, Except for GPIO (continued) Function I2C Pin Name Pin Number Pin Type Buffer Type Description I2C0SCL 91 I/O OD I2C I2C0SDA 92 I/O OD I2C module 0 data. I2C1SCL 49 I/O OD I2C module 1 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C1SDA 50 I/O OD I2C module 1 data. I2C2SCL 82 106 112 I/O OD I2C module 2 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C2SDA 81 111 I/O OD I2C module 2 data. I2C3SCL 63 I/O OD I2C module 3 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C3SDA 62 I/O OD I2C module 3 data. I2C4SCL 61 I/O OD I2C module 4 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C4SDA 60 I/O OD I2C module 4 data. I2C5SCL 95 121 I/O OD I2C module 5 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C5SDA 96 120 I/O OD I2C module 5 data. I2C6SCL 40 I/O OD I2C module 6 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C6SDA 41 I/O OD I2C module 6 data. I2C7SCL 1 37 I/O OD I2C module 7 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C7SDA 2 38 I/O OD I2C module 7 data. I2C8SCL 3 35 I/O OD I2C module 8 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C8SDA 4 36 I/O OD I2C module 8 data. I2C9SCL 33 I/O OD I2C module 9 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. I2C9SDA 34 I/O OD I2C module 9 data. module 0 clock. Note that this signal has an active pull-up. The corresponding port pin should not be configured as open drain. 1802 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-4. Signals by Function, Except for GPIO (continued) Function JTAG/SWD/SWO Pin Name Pin Number Pin Type Buffer Type Description SWCLK 100 I TTL JTAG/SWD CLK. SWDIO 99 I/O TTL JTAG TMS and SWDIO. SWO 97 O TTL JTAG TDO and SWO. TCK 100 I TTL JTAG/SWD CLK. TDI 98 I TTL JTAG TDI. TDO 97 O TTL JTAG TDO and SWO. TMS 99 I TTL JTAG TMS and SWDIO. M0FAULT0 46 I TTL Motion Control Module 0 PWM Fault 0. M0FAULT1 61 I TTL Motion Control Module 0 PWM Fault 1. M0FAULT2 60 I TTL Motion Control Module 0 PWM Fault 2. M0FAULT3 81 I TTL Motion Control Module 0 PWM Fault 3. M0PWM0 42 O TTL Motion Control Module 0 PWM 0. This signal is controlled by Module 0 PWM Generator 0. M0PWM1 43 O TTL Motion Control Module 0 PWM 1. This signal is controlled by Module 0 PWM Generator 0. M0PWM2 44 O TTL Motion Control Module 0 PWM 2. This signal is controlled by Module 0 PWM Generator 1. M0PWM3 45 O TTL Motion Control Module 0 PWM 3. This signal is controlled by Module 0 PWM Generator 1. M0PWM4 49 O TTL Motion Control Module 0 PWM 4. This signal is controlled by Module 0 PWM Generator 2. M0PWM5 50 O TTL Motion Control Module 0 PWM 5. This signal is controlled by Module 0 PWM Generator 2. M0PWM6 63 O TTL Motion Control Module 0 PWM 6. This signal is controlled by Module 0 PWM Generator 3. M0PWM7 62 O TTL Motion Control Module 0 PWM 7. This signal is controlled by Module 0 PWM Generator 3. PWM June 18, 2014 1803 Texas Instruments-Production Data Signal Tables Table 26-4. Signals by Function, Except for GPIO (continued) Function Pin Name Pin Number Pin Type Buffer Type GND 17 48 55 58 80 114 - Power Ground reference for logic and I/O pins. GNDA 10 - Power The ground reference for the analog circuits (ADC, Analog Comparators, etc.). These are separated from GND to minimize the electrical noise contained on VDD from affecting the analog functions. VDD 7 16 26 28 39 47 51 52 69 79 90 101 113 122 - Power Positive supply for I/O and some logic. VDDA 8 - Power The positive supply for the analog circuits (ADC, Analog Comparators, etc.). These are separated from VDD to minimize the electrical noise contained on VDD from affecting the analog functions. VDDA pins must be supplied with a voltage that meets the specification in , regardless of system implementation. VDDC 87 115 - Power Positive supply for most of the logic function, including the processor core and most peripherals. The voltage on this pin is 1.2 V and is supplied by the on-chip LDO. The VDDC pins should only be connected to each other and an external capacitor as specified in Table 27-15 on page 1834 . IDX0 84 I TTL QEI module 0 index. PhA0 82 I TTL QEI module 0 phase A. PhB0 83 I TTL QEI module 0 phase B. Power QEI Description 1804 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-4. Signals by Function, Except for GPIO (continued) Function Pin Name Pin Number Pin Type Buffer Type SSI0Clk 35 I/O TTL SSI module 0 clock SSI0Fss 36 I/O TTL SSI module 0 frame signal SSI0XDAT0 37 I/O TTL SSI Module 0 Bi-directional Data Pin 0 (SSI0TX in Legacy SSI Mode). SSI0XDAT1 38 I/O TTL SSI Module 0 Bi-directional Data Pin 1 (SSI0RX in Legacy SSI Mode). SSI0XDAT2 40 I/O TTL SSI Module 0 Bi-directional Data Pin 2. SSI0XDAT3 41 I/O TTL SSI Module 0 Bi-directional Data Pin 3. SSI1Clk 120 I/O TTL SSI module 1 clock. SSI1Fss 121 I/O TTL SSI module 1 frame signal. SSI1XDAT0 123 I/O TTL SSI Module 1 Bi-directional Data Pin 0 (SSI1TX in Legacy SSI Mode). SSI1XDAT1 124 I/O TTL SSI Module 1 Bi-directional Data Pin 1 (SSI1RX in Legacy SSI Mode). SSI1XDAT2 125 I/O TTL SSI Module 1 Bi-directional Data Pin 2. SSI1XDAT3 126 I/O TTL SSI Module 1 Bi-directional Data Pin 3. SSI2Clk 4 I/O TTL SSI module 2 clock. SSI2Fss 3 I/O TTL SSI module 2 frame signal. SSI2XDAT0 2 I/O TTL SSI Module 2 Bi-directional Data Pin 0 (SSI2TX in Legacy SSI Mode). SSI2XDAT1 1 I/O TTL SSI Module 2 Bi-directional Data Pin 1 (SSI2RX in Legacy SSI Mode). SSI2XDAT2 128 I/O TTL SSI Module 2 Bi-directional Data Pin 2. SSI2XDAT3 127 I/O TTL SSI Module 2 Bi-directional Data Pin 3. SSI3Clk 5 45 I/O TTL SSI module 3 clock. SSI3Fss 6 44 I/O TTL SSI module 3 frame signal. SSI3XDAT0 11 43 I/O TTL SSI Module 3 Bi-directional Data Pin 0 (SSI3TX in Legacy SSI Mode). SSI3XDAT1 27 42 I/O TTL SSI Module 3 Bi-directional Data Pin 1 (SSI3RX in Legacy SSI Mode). SSI3XDAT2 46 118 I/O TTL SSI Module 3 Bi-directional Data Pin 2. SSI3XDAT3 119 I/O TTL SSI Module 3 Bi-directional Data Pin 3. DIVSCLK 102 O TTL An optionally divided reference clock output based on a selected clock source. Note that this signal is not synchronized to the System Clock. NMI 128 I TTL Non-maskable interrupt. OSC0 88 I Analog Main oscillator crystal input or an external clock reference input. OSC1 89 O Analog Main oscillator crystal output. Leave unconnected when using a single-ended clock source. RST 70 I TTL SSI System Control & Clocks Description System reset input. June 18, 2014 1805 Texas Instruments-Production Data Signal Tables Table 26-4. Signals by Function, Except for GPIO (continued) Function Pin Name Pin Number Pin Type Buffer Type Description U0CTS 30 74 121 I TTL UART module 0 Clear To Send modem flow control input signal. U0DCD 31 73 104 I TTL UART module 0 Data Carrier Detect modem status input signal. U0DSR 32 72 105 I TTL UART module 0 Data Set Ready modem output control line. U0DTR 103 O TTL UART module 0 Data Terminal Ready modem status input signal. U0RI 60 71 I TTL UART module 0 Ring Indicator modem status input signal. U0RTS 29 120 O TTL UART module 0 Request to Send modem flow control output signal. U0Rx 33 I TTL UART module 0 receive. U0Tx 34 O TTL UART module 0 transmit. U1CTS 104 108 I TTL UART module 1 Clear To Send modem flow control input signal. U1DCD 13 109 I TTL UART module 1 Data Carrier Detect modem status input signal. U1DSR 14 110 I TTL UART module 1 Data Set Ready modem output control line. U1DTR 12 111 O TTL UART module 1 Data Terminal Ready modem status input signal. U1RI 112 123 I TTL UART module 1 Ring Indicator modem status input signal. U1RTS 15 107 O TTL UART module 1 Request to Send modem flow control output line. U1Rx 95 102 I TTL UART module 1 receive. U1Tx 96 O TTL UART module 1 transmit. U2CTS 110 128 I TTL UART module 2 Clear To Send modem flow control input signal. U2RTS 109 127 O TTL UART module 2 Request to Send modem flow control output line. U2Rx 40 125 I TTL UART module 2 receive. U2Tx 41 126 O TTL UART module 2 transmit. U3CTS 106 112 I TTL UART module 3 Clear To Send modem flow control input signal. U3RTS 105 111 O TTL UART module 3 Request to Send modem flow control output line. U3Rx 37 116 I TTL UART module 3 receive. U3Tx 38 117 O TTL UART module 3 transmit. U4CTS 21 I TTL UART 1806 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-4. Signals by Function, Except for GPIO (continued) Function Pin Name Pin Number Pin Type Buffer Type Description UART module 4 Clear To Send modem flow control input signal. USB U4RTS 20 O TTL UART module 4 Request to Send modem flow control output line. U4Rx 18 35 I TTL UART module 4 receive. U4Tx 19 36 O TTL UART module 4 transmit. U5Rx 23 I TTL UART module 5 receive. U5Tx 22 O TTL UART module 5 transmit. U6Rx 118 I TTL UART module 6 receive. U6Tx 119 O TTL UART module 6 transmit. U7Rx 25 I TTL UART module 7 receive. U7Tx 24 O TTL UART module 7 transmit. USB0CLK 92 O TTL 60-MHz clock to the external PHY. USB0D0 81 I/O TTL USB data 0. USB0D1 82 I/O TTL USB data 1. USB0D2 83 I/O TTL USB data 2. USB0D3 84 I/O TTL USB data 3. USB0D4 85 I/O TTL USB data 4. USB0D5 86 I/O TTL USB data 5. USB0D6 106 I/O TTL USB data 6. USB0D7 105 I/O TTL USB data 7. USB0DIR 104 O TTL Indicates that the external PHY is able to accept data from the USB controller. USB0DM 93 I/O Analog Bidirectional differential data pin (D- per USB specification) for USB0. USB0DP 94 I/O Analog Bidirectional differential data pin (D+ per USB specification) for USB0. USB0EPEN 40 41 127 O TTL Optionally used in Host mode to control an external power source to supply power to the USB bus. USB0ID 95 I Analog This signal senses the state of the USB ID signal. The USB PHY enables an integrated pull-up, and an external element (USB connector) indicates the initial state of the USB controller (pulled down is the A side of the cable and pulled up is the B side). USB0NXT 103 O TTL Asserted by the external PHY to throttle all data types. USB0PFLT 41 128 I TTL Optionally used in Host mode by an external power source to indicate an error state by that power source. USB0STP 91 O TTL Asserted by the USB controller to signal the end of a USB transmit packet or register write operation. USB0VBUS 96 I/O Analog This signal is used during the session request protocol. This signal allows the USB PHY to both sense the voltage level of VBUS, and pull up VBUS momentarily during VBUS pulsing. June 18, 2014 1807 Texas Instruments-Production Data Signal Tables 26.4 GPIO Pins and Alternate Functions Table 26-5. GPIO Pins and Alternate Functions b IO Pin Analog or Special a Function Digital Function (GPIOPCTL PMCx Bit Field Encoding) PA0 33 - U0Rx PA1 34 - U0Tx PA2 35 - PA3 36 - PA4 37 PA5 1 2 3 4 5 6 7 8 11 13 14 15 I2C9SCL T0CCP0 - - - CAN0Rx - - - - - I2C9SDA T0CCP1 - - - CAN0Tx - - - - - U4Rx I2C8SCL T1CCP0 - - - - - - - - SSI0Clk U4Tx I2C8SDA T1CCP1 - - - - - - - - SSI0Fss - U3Rx I2C7SCL T2CCP0 - - - - - - - - SSI0XDAT0 38 - U3Tx I2C7SDA T2CCP1 - - - - - - - - SSI0XDAT1 PA6 40 - U2Rx I2C6SCL T3CCP0 - USB0EPEN - - - - SSI0XDAT2 - EPI0S8 PA7 41 - U2Tx I2C6SDA T3CCP1 - USB0PFLT - - - USB0EPEN SSI0XDAT3 - EPI0S9 PB0 95 USB0ID U1Rx I2C5SCL T4CCP0 - - - CAN1Rx - - - - - PB1 96 USB0VBUS U1Tx I2C5SDA T4CCP1 - - - CAN1Tx - - - - - PB2 91 - - I2C0SCL T5CCP0 - - - - - - - USB0STP EPI0S27 PB3 92 - - I2C0SDA T5CCP1 - - - - - - - USB0CLK EPI0S28 PB4 121 AIN10 U0CTS I2C5SCL - - - - - - - - - SSI1Fss PB5 120 AIN11 U0RTS I2C5SDA - - - - - - - - - SSI1Clk PC0 100 - TCK SWCLK - - - - - - - - - - - PC1 99 - TMS SWDIO - - - - - - - - - - - PC2 98 - TDI - - - - - - - - - - - PC3 97 - TDO SWO - - - - - - - - - - - PC4 25 C1- U7Rx - - - - - - - - - - EPI0S7 PC5 24 C1+ U7Tx - - - - - RTCCLK - - - - EPI0S6 PC6 23 C0+ U5Rx - - - - - - - - - - EPI0S5 PC7 22 C0- U5Tx - - - - - - - - - - EPI0S4 PD0 1 AIN15 - I2C7SCL T0CCP0 - C0o - - - - - - SSI2XDAT1 PD1 2 AIN14 - I2C7SDA T0CCP1 - C1o - - - - - - SSI2XDAT0 PD2 3 AIN13 - I2C8SCL T1CCP0 - C2o - - - - - - SSI2Fss PD3 4 AIN12 - I2C8SDA T1CCP1 - - - - - - - - SSI2Clk PD4 125 AIN7 U2Rx - T3CCP0 - - - - - - - - SSI1XDAT2 PD5 126 AIN6 U2Tx - T3CCP1 - - - - - - - - SSI1XDAT3 PD6 127 AIN5 U2RTS - T4CCP0 - USB0EPEN - - - - - - SSI2XDAT3 PD7 128 AIN4 U2CTS - T4CCP1 - USB0PFLT - - NMI - - - SSI2XDAT2 PE0 15 AIN3 U1RTS - - - - - - - - - - - PE1 14 AIN2 U1DSR - - - - - - - - - - - PE2 13 AIN1 U1DCD - - - - - - - - - - - PE3 12 AIN0 U1DTR - - - - - - - - - - - PE4 123 AIN9 U1RI - - - - - - - - - - SSI1XDAT0 1808 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-5. GPIO Pins and Alternate Functions (continued) b IO Pin Analog or Special a Function Digital Function (GPIOPCTL PMCx Bit Field Encoding) PE5 124 AIN8 - - - - PF0 42 - - - - - EN0LED0 M0PWM0 - - - - SSI3XDAT1 TRD2 PF1 43 - - - - - EN0LED2 M0PWM1 - - - - SSI3XDAT0 TRD1 PF2 44 - - - - - TRD0 1 2 3 4 5 6 7 8 11 13 14 15 - - - - - - - SSI1XDAT1 - M0PWM2 - - - - SSI3Fss - PF3 45 - - - - - M0PWM3 - - - - SSI3Clk TRCLK PF4 46 - - - - - EN0LED1 M0FAULT0 - - - - SSI3XDAT2 TRD3 PG0 49 - - I2C1SCL - - EN0PPS M0PWM4 - - - - - EPI0S11 PG1 50 - - I2C1SDA - - - M0PWM5 - - - - - EPI0S10 PH0 29 - U0RTS - - - - - - - - - - EPI0S0 PH1 30 - U0CTS - - - - - - - - - - EPI0S1 PH2 31 - U0DCD - - - - - - - - - - EPI0S2 PH3 32 - U0DSR - - - - - - - - - - EPI0S3 PJ0 116 - U3Rx - - - EN0PPS - - - - - - - PJ1 117 - U3Tx - - - - - - - - - - - PK0 18 AIN16 U4Rx - - - - - - - - - - EPI0S0 PK1 19 AIN17 U4Tx - - - - - - - - - - EPI0S1 PK2 20 AIN18 U4RTS - - - - - - - - - - EPI0S2 PK3 21 AIN19 U4CTS - - - - - - - - - - EPI0S3 PK4 63 - - I2C3SCL - - EN0LED0 M0PWM6 - - - - - EPI0S32 PK5 62 - - I2C3SDA - - EN0LED2 M0PWM7 - - - - - EPI0S31 PK6 61 - - I2C4SCL - - EN0LED1 M0FAULT1 - - - - - EPI0S25 PK7 60 - U0RI I2C4SDA - - RTCCLK M0FAULT2 - - - - - EPI0S24 PL0 81 - - I2C2SDA - - - M0FAULT3 - - - - USB0D0 EPI0S16 PL1 82 - - I2C2SCL - - - PhA0 - - - - USB0D1 EPI0S17 PL2 83 - - - - - C0o PhB0 - - - - USB0D2 EPI0S18 PL3 84 - - - - - C1o IDX0 - - - - USB0D3 EPI0S19 PL4 85 - - - T0CCP0 - - - - - - - USB0D4 EPI0S26 USB0D5 EPI0S33 PL5 86 - - - T0CCP1 - - - - - - - PL6 94 USB0DP - - T1CCP0 - - - - - - - - - PL7 93 USB0DM - - T1CCP1 - - - - - - - - - PM0 78 - - - T2CCP0 - - - - - - - - EPI0S15 PM1 77 - - - T2CCP1 - - - - - - - - EPI0S14 PM2 76 - - - T3CCP0 - - - - - - - - EPI0S13 PM3 75 - - - T3CCP1 - - - - - - - - EPI0S12 PM4 74 TMPR3 U0CTS - T4CCP0 - - - - - - - - - PM5 73 TMPR2 U0DCD - T4CCP1 - - - - - - - - - PM6 72 TMPR1 U0DSR - T5CCP0 - - - - - - - - - PM7 71 TMPR0 U0RI - T5CCP1 - - - - - - - - - PN0 107 - U1RTS - - - - - - - - - - - June 18, 2014 1809 Texas Instruments-Production Data Signal Tables Table 26-5. GPIO Pins and Alternate Functions (continued) b IO Pin Analog or Special a Function Digital Function (GPIOPCTL PMCx Bit Field Encoding) PN1 108 - U1CTS - - - - - - - - - - - PN2 109 - U1DCD U2RTS - - - - - - - - - EPI0S29 PN3 110 - U1DSR U2CTS - - - - - - - - - EPI0S30 PN4 111 - U1DTR U3RTS I2C2SDA - - - - - - - - EPI0S34 PN5 112 - U1RI U3CTS I2C2SCL - - - - - - - - EPI0S35 PP0 118 C2+ U6Rx - - - - - - - - - - SSI3XDAT2 PP1 119 C2- U6Tx - - - - - - - - - - SSI3XDAT3 PP2 103 - U0DTR - - - - - - - - - USB0NXT EPI0S29 PP3 104 - U1CTS U0DCD - - - - RTCCLK - - - USB0DIR EPI0S30 U0DSR - - - - - - - - USB0D7 - - - - - - - - - USB0D6 - 1 2 3 4 5 6 7 8 11 13 14 15 PP4 105 - U3RTS PP5 106 - U3CTS I2C2SCL PQ0 5 - - - - - - - - - - - SSI3Clk EPI0S20 PQ1 6 - - - - - - - - - - - SSI3Fss EPI0S21 PQ2 11 - - - - - - - - - - - SSI3XDAT0 EPI0S22 SSI3XDAT1 EPI0S23 PQ3 27 - - - - - - - - - - - PQ4 102 - U1Rx - - - - - DIVSCLK - - - - - a. The TMPRn signals are digital signals enabled and configured by the Hibernation module. All other signals listed in this column are analog signals. b. The digital signals that are shaded gray are the power-on default values for the corresponding GPIO pin. Encodings 9, 10, and 12 are not used on this device. 1810 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 26.5 Possible Pin Assignments for Alternate Functions Table 26-6. Possible Pin Assignments for Alternate Functions # of Possible Assignments one Alternate Function GPIO Function AIN0 PE3 AIN1 PE2 AIN10 PB4 AIN11 PB5 AIN12 PD3 AIN13 PD2 AIN14 PD1 AIN15 PD0 AIN16 PK0 AIN17 PK1 AIN18 PK2 AIN19 PK3 AIN2 PE1 AIN3 PE0 AIN4 PD7 AIN5 PD6 AIN6 PD5 AIN7 PD4 AIN8 PE5 AIN9 PE4 C0+ PC6 C0- PC7 C1+ PC5 C1- PC4 C2+ PP0 C2- PP1 C2o PD2 CAN0Rx PA0 CAN0Tx PA1 CAN1Rx PB0 CAN1Tx PB1 DIVSCLK PQ4 EPI0S10 PG1 EPI0S11 PG0 EPI0S12 PM3 EPI0S13 PM2 EPI0S14 PM1 EPI0S15 PM0 EPI0S16 PL0 June 18, 2014 1811 Texas Instruments-Production Data Signal Tables Table 26-6. Possible Pin Assignments for Alternate Functions (continued) # of Possible Assignments Alternate Function GPIO Function EPI0S17 PL1 EPI0S18 PL2 EPI0S19 PL3 EPI0S20 PQ0 EPI0S21 PQ1 EPI0S22 PQ2 EPI0S23 PQ3 EPI0S24 PK7 EPI0S25 PK6 EPI0S26 PL4 EPI0S27 PB2 EPI0S28 PB3 EPI0S31 PK5 EPI0S32 PK4 EPI0S33 PL5 EPI0S34 PN4 EPI0S35 PN5 EPI0S4 PC7 EPI0S5 PC6 EPI0S6 PC5 EPI0S7 PC4 EPI0S8 PA6 EPI0S9 PA7 I2C0SCL PB2 I2C0SDA PB3 I2C1SCL PG0 I2C1SDA PG1 I2C3SCL PK4 I2C3SDA PK5 I2C4SCL PK6 I2C4SDA PK7 I2C6SCL PA6 I2C6SDA PA7 I2C9SCL PA0 I2C9SDA PA1 IDX0 PL3 M0FAULT0 PF4 M0FAULT1 PK6 M0FAULT2 PK7 M0FAULT3 PL0 M0PWM0 PF0 1812 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-6. Possible Pin Assignments for Alternate Functions (continued) # of Possible Assignments Alternate Function GPIO Function M0PWM1 PF1 M0PWM2 PF2 M0PWM3 PF3 M0PWM4 PG0 M0PWM5 PG1 M0PWM6 PK4 M0PWM7 PK5 NMI PD7 PhA0 PL1 PhB0 PL2 SSI0Clk PA2 SSI0Fss PA3 SSI0XDAT0 PA4 SSI0XDAT1 PA5 SSI0XDAT2 PA6 SSI0XDAT3 PA7 SSI1Clk PB5 SSI1Fss PB4 SSI1XDAT0 PE4 SSI1XDAT1 PE5 SSI1XDAT2 PD4 SSI1XDAT3 PD5 SSI2Clk PD3 SSI2Fss PD2 SSI2XDAT0 PD1 SSI2XDAT1 PD0 SSI2XDAT2 PD7 SSI2XDAT3 PD6 SSI3XDAT3 PP1 SWCLK PC0 SWDIO PC1 SWO PC3 TCK PC0 TDI PC2 TDO PC3 TMPR0 PM7 TMPR1 PM6 TMPR2 PM5 TMPR3 PM4 TMS PC1 TRCLK PF3 June 18, 2014 1813 Texas Instruments-Production Data Signal Tables Table 26-6. Possible Pin Assignments for Alternate Functions (continued) # of Possible Assignments Alternate Function GPIO Function TRD0 PF2 TRD1 PF1 TRD2 PF0 TRD3 PF4 U0DTR PP2 U0Rx PA0 U0Tx PA1 U1Tx PB1 U4CTS PK3 U4RTS PK2 U5Rx PC6 U5Tx PC7 U6Rx PP0 U6Tx PP1 U7Rx PC4 U7Tx PC5 USB0CLK PB3 USB0D0 PL0 USB0D1 PL1 USB0D2 PL2 USB0D3 PL3 USB0D4 PL4 USB0D5 PL5 USB0D6 PP5 USB0D7 PP4 USB0DIR PP3 USB0DM PL7 USB0DP PL6 USB0ID PB0 USB0NXT PP2 USB0STP PB2 USB0VBUS PB1 1814 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-6. Possible Pin Assignments for Alternate Functions (continued) # of Possible Assignments two Alternate Function GPIO Function C0o PD0 PL2 C1o PD1 PL3 EN0LED0 PF0 PK4 EN0LED1 PF4 PK6 EN0LED2 PF1 PK5 EN0PPS PG0 PJ0 EPI0S0 PH0 PK0 EPI0S1 PH1 PK1 EPI0S2 PH2 PK2 EPI0S29 PN2 PP2 EPI0S3 PH3 PK3 EPI0S30 PN3 PP3 I2C2SDA PL0 PN4 I2C5SCL PB0 PB4 I2C5SDA PB1 PB5 I2C7SCL PA4 PD0 I2C7SDA PA5 PD1 I2C8SCL PA2 PD2 I2C8SDA PA3 PD3 SSI3Clk PF3 PQ0 SSI3Fss PF2 PQ1 SSI3XDAT0 PF1 PQ2 SSI3XDAT1 PF0 PQ3 SSI3XDAT2 PF4 PP0 T2CCP0 PA4 PM0 T2CCP1 PA5 PM1 T5CCP0 PB2 PM6 T5CCP1 PB3 PM7 U0RI PK7 PM7 U0RTS PB5 PH0 U1CTS PN1 PP3 U1DCD PE2 PN2 U1DSR PE1 PN3 U1DTR PE3 PN4 U1RI PE4 PN5 U1RTS PE0 PN0 U1Rx PB0 PQ4 U2CTS PD7 PN3 U2RTS PD6 PN2 U2Rx PA6 PD4 U2Tx PA7 PD5 June 18, 2014 1815 Texas Instruments-Production Data Signal Tables Table 26-6. Possible Pin Assignments for Alternate Functions (continued) # of Possible Assignments Alternate Function GPIO Function U3CTS PN5 PP5 U3RTS PN4 PP4 U3Rx PA4 PJ0 U3Tx PA5 PJ1 U4Rx PA2 PK0 U4Tx PA3 PK1 USB0PFLT PA7 PD7 I2C2SCL PL1 PN5 PP5 RTCCLK PC5 PK7 PP3 T0CCP0 PA0 PD0 PL4 T0CCP1 PA1 PD1 PL5 T1CCP0 PA2 PD2 PL6 T1CCP1 PA3 PD3 PL7 T3CCP0 PA6 PD4 PM2 T3CCP1 PA7 PD5 PM3 T4CCP0 PB0 PD6 PM4 T4CCP1 PB1 PD7 PM5 U0CTS PB4 PH1 PM4 U0DCD PH2 PM5 PP3 U0DSR PH3 PM6 PP4 USB0EPEN PA6 PA7 PD6 three 26.6 Connections for Unused Signals Table 26-7 on page 1816 shows how to handle signals for functions that are not used in a particular system implementation for devices that are in a 128-pin TQFP package. Two options are shown in the table: an acceptable practice and a preferred practice for reduced power consumption and improved EMC characteristics. If a module is not used in a system, and its inputs are grounded, it is important that the clock to the module is never enabled by setting the corresponding bit in the RCGCx register. Table 26-7. Connections for Unused Signals (128-Pin TQFP) Function ADC Ethernet GPIO Signal Name Pin Number Acceptable Practice Preferred Practice VREFA+ 9 VDDA VDDA EN0RXIN 53 NC NC EN0RXIP 54 NC NC EN0TXON 56 NC NC EN0TXOP 57 NC NC RBIAS 59 Connect to ground through 4.87K resistor NC PA1(UART0TX) 34 NC GND PA4 (SSI0XDAT0) 37 NC GND All unused GPIOs - NC GND 1816 a b c June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 26-7. Connections for Unused Signals (128-Pin TQFP) (continued) Function Hibernate No Connects System Control Signal Name Pin Number Acceptable Practice Preferred Practice HIB 65 NC NC VBAT 68 NC VDD WAKE 64 NC GND XOSC0 66 NC GND XOSC1 67 NC NC NC See NC pin numbers in Table 26-3 on page 1785 NC NC OSC0 88 NC GND OSC1 89 NC NC RST 70 VDD Pull up as shown in Figure 5-1 on page 224 USB0DM / PL7 93 NC Pull-down to GND with 1K d resistor USB0DP / PL6 94 NC Pull-down to GND with 1K d resistor USB a. The internal Ethernet PHY should not be enabled when RBIAS is not connected. The ROM boot loader will enable the internal Ethernet Phy if no code is present in the flash and a 24-25Mhz crystal is attached to the OSC0/1 pins. b. PA1 (UART0TX) may be enabled as an output by the ROM boot loader if no code is present in the flash and PA0 (UART0RX) receives a valid boot signature. Ensure that this condition will not occur if PA1 is to be connected directly to GND. c. PA4 (SSI0XDAT0) may be enabled as an output by the ROM boot loader if no code is present in the flash and the SSI0x (PA2, PA3, PA5) receives a valid boot signature. Ensure that this condition will not occur if PA4 is to be connected directly to GND. d. The ROM boot loader may configure these pins as USB pins if no code is present in the flash therefore they should not be directly connected to ground. June 18, 2014 1817 Texas Instruments-Production Data Electrical Characteristics 27 Electrical Characteristics 27.1 Maximum Ratings The maximum ratings are the limits to which the device can be subjected without permanently damaging the device. Device reliability may be adversely affected by exposure to absolute-maximum ratings for extended periods. Note: The device is not guaranteed to operate properly at the maximum ratings. Table 27-1. Absolute Maximum Ratings Value a Parameter Parameter Name VDD Unit Min Max VDD supply voltage 0 4 V VDDA VDDA supply voltage 0 4 V VBAT VBAT battery supply voltage 0 4 V VBAT battery supply voltage ramp time 0 0.7 V/µs VBATRMP b VIN_GPIO Input voltage IGPIOMAX Maximum current per output pin TS TJMAX Unpowered storage temperature range Maximum junction temperature -0.3 4 V - 64 mA -65 150 °C - 125 °C a. Voltages are measured with respect to GND. b. Applies to static and dynamic signals including overshoot. Important: This device contains circuitry to protect the I/Os against damage due to high-static voltages; however, it is advised that normal precautions be taken to avoid application of any voltage higher than maximum-rated voltages to this high-impedance circuit. Reliability of operation is enhanced if unused inputs are connected to an appropriate logic voltage level (see “Connections for Unused Signals” on page 1816). Table 27-2. ESD Absolute Maximum Ratings Parameter Parameter Name Component-Level ESD Stress a Voltage b VESDHBM c VESDCDM Min Nom Max Unit - - 2.0 kV - 500 V a. Electrostatic discharge (ESD) is used to measure device sensitivity/immunity to damage caused by electrostatic discharges in device. b. All pins are HBM compliant to 2 kV for all combinations as per JESD22-A114F, except for the following stress combinations: ■ The Ethernet EN0RXIN, EN0TX0N, EN0RXIP, and EN0TXOP pins to each other. ■ The GPIO pins PM4, PM5, PM6, and PM7 to other pins. These exceptions are compliant to 500 V and do not require any special handling beyond typical ESD control procedures during assembly operations per JEDEC publication JEP155. Note that these pins do meet the 500 V CDM specification. c. Level listed is the passing level per EIA-JEDEC JESD22-C101E. JEDEC document JEP157 states that 250 V CDM allows safe manufacturing with a standard ESD control process. 1818 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.2 Operating Characteristics Table 27-3. Temperature Characteristics Characteristic Symbol Value Unit Ambient operating temperature range TA -40 to 85 (industrial temperature part) °C -40 to 105 (extended temperature part) Junction operating temperature range TJ -40 to 105 (industrial temperature part) °C -40 to 125 (extended temperature part) ab Table 27-4. 128-pin TQFP Power Dissipation Parameter Parameter Name TA TJ Min Max Unit PDI Industrial temperature device power dissipation 85 °C (industrial temperature part) 125 °C (industrial temperature part) - 904 mW PDE Extended temperature device 105 °C (extended power dissipation temperature part) 125 °C (extended temperature part) - 452 mW a. If the device exceeds the power dissipation value shown, then modifications such as heat sinks or fans must be used to conform to the limits shown. b. A larger power dissipation allowance can be achieved by lowering TA as long as TJMAX shown in Table 27-1 on page 1818 is not exceeded. a Table 27-5. Thermal Characteristics Characteristic Symbol b Thermal resistance (junction to ambient) ΘJA b Value Unit 44.2 °C/W Thermal resistance (junction to board) ΘJB 22.4 °C/W Thermal resistance (junction to case) b ΘJC 6.8 °C/W Thermal metric (junction to top of package) ΨJT 0.2 °C/W Thermal metric (junction to board) ΨJB 22.1 Junction temperature formula TJ °C/W c TC + (P • ΨJT) °C d TPCB + (P • ΨJB) e TA + (P • ΘJA) fg TB + (P • ΘJB) a. For more details about thermal metrics and definitions, see the Semiconductor and IC Package Thermal Metrics Application Report (literature number SPRA953). b. Junction to ambient thermal resistance (ΘJA), junction to board thermal resistance (ΘJB), and junction to case thermal resistance (ΘJC) numbers are determined by a package simulator. c. TC is the case temperature and P is the device power consumption. d. TPCB is the temperature of the board acquired by following the steps listed in the EAI/JESD 51-8 standard summarized in the Semiconductor and IC Package Thermal Metrics Application Report (literature number SPRA953). P is the device power consumption. e. Because ΘJA is highly variable and based on factors such as board design, chip/pad size, altitude, and external ambient temperature, it is recommended that equations containing ΨJT and ΨJB be used for best results. f. TB is temperature of the board. g. ΘJB is not a pure reflection of the internal resistance of the package because it includes the resistance of the testing board and environment. It is recommended that equations containing ΨJT and ΨJB be used for best results. June 18, 2014 1819 Texas Instruments-Production Data Electrical Characteristics 27.3 Recommended Operating Conditions The following sections describe the recommended DC operating conditions and GPIO operating characteristics for the device. 27.3.1 DC Operating Conditions Table 27-6. Recommended DC Operating Conditions Parameter Parameter Name Min Nom Max Unit VDD VDD supply voltage 2.97 3.3 3.63 V a VDDA VDDA supply voltage 2.97 3.3 3.63 V VDDC VDDC supply voltage, Run mode 1.14 1.2 1.32 V VDDC supply voltage, Deep-Sleep mode 0.85 - 0.95 V VDDCDS a. To ensure proper operation, VDDA must be powered up before VDD if sourced from different supplies, or connected to the same supply as VDD. There is not a restriction on order for powering off. 27.3.2 Recommended GPIO Operating Characteristics Two types of pads are provided on the device: ■ Fast GPIO pads: These pads provide variable, programmable drive strength and optimized voltage output levels. ■ Slow GPIO pads: These pads provide 2-mA drive strength and are designed to be sensitive to voltage inputs. The following GPIOs port pins are designed with Slow GPIO Pads: – PJ1 All other GPIOs have a fast GPIO pad-type. Note: Port pins PL6 and PL7 operate as Fast GPIO pads, but have 4-mA drive capability only. GPIO register controls for drive strength, slew rate and open drain have no effect on these pins. The registers which have no effect are as follows: GPIODR2R, GPIODR4R, GPIODR8R, GPIODR12R, GPIOSLR, and GPIOODR. Note: Port pins PM[7:4] operate as Fast GPIO pads but support only 2-, 4-, 6-, and 8-mA drive capability. 10- and 12-mA drive are not supported. All standard GPIO register controls, except for the GPIODR12R register, apply to these port pins. Table 27-7 on page 1820 detail the GPIO operating conditions for these two different pad types. Table 27-7. Recommended FAST GPIO Pad Operating Conditions Parameter Parameter Name VIH Fast GPIO high-level input voltage I IH Fast GPIO high-level input current VIL Fast GPIO low-level input voltage I IL Fast GPIO low-level input current a a Min Nom Max Unit 0.65 * VDD - 4 V - - 300 nA 0 - 0.35 * VDD V - - -200 nA VHYS Fast GPIO Input Hysteresis 0.49 - - V VOH Fast GPIO High-level output voltage 2.4 - - V VOL Fast GPIO Low-level output voltage - - 0.40 V 1820 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-7. Recommended FAST GPIO Pad Operating Conditions (continued) Parameter Parameter Name Min Nom Max Unit 2-mA Drive 2.0 - - mA 4-mA Drive 4.0 - - mA 8-mA Drive 8.0 - - mA 10-mA Drive 10.0 - - mA 12.0 - - mA 2-mA Drive 2.0 - - mA 4-mA Drive 4.0 - - mA 8-mA Drive 8.0 - - mA 10-mA Drive 10.0 - - mA 12-mA Drive 12.0 - - mA 12-mA Drive overdriven to 18-mA 18.0 - - mA b Fast GPIO High-level source current, VOH=2.4 V IOH 12-mA Drive b Fast GPIO Low-level sink current, VOL=0.4 V IOL a. Output/pull-up/pull-down disabled; only input enabled b. IO specifications reflect the maximum current where the corresponding output voltage meets the VOH/VOL thresholds. IO current can exceed these limits (subject to absolute maximum ratings). Table 27-8. Recommended Slow GPIO Pad Operating Conditions Parameter Parameter Name Min VIH Slow GPIO high-level input voltage I IH Slow GPIO high-level input current VIL Slow GPIO low-level input voltage I IL Nom Max Unit 0.65 * VDD - 4 V - - 4.1 nA 0 - 0.35 * VDD V a a - - -1 nA VHYS Slow GPIO low-level input current Slow GPIO Input Hysteresis 0.49 - - V VOH Slow GPIO High-level output voltage 2.4 - - V VOL Slow GPIO Low-level output voltage - - 0.4 V 2.0 - - mA 2.0 - - mA b IOH High-level source current, VOH=2.4 V 2-mA Drive b IOL Low-level sink current, VOL=0.4 V 2-mA Drive a. Output/pull-up/pull-down disabled; only input enabled. b. IO specifications reflect the maximum current where the corresponding output voltage meets the VOH/VOL thresholds. IO current can exceed these limits (subject to absolute maximum ratings). 27.3.2.1 GPIO Current Restrictions a Table 27-9. GPIO Current Restrictions Parameter Min Nom Max Unit IMAXL Parameter Name Cumulative maximum GPIO current per side, left - - 112 mA IMAXB Cumulative maximum GPIO current per side, b bottom - - 97.6 mA IMAXR Cumulative maximum GPIO current per side, right - - 112 mA b b June 18, 2014 1821 Texas Instruments-Production Data Electrical Characteristics Table 27-9. GPIO Current Restrictions (continued) Parameter Parameter Name Min Nom Max Unit - - 80 mA b IMAXT Cumulative maximum GPIO current per side, top a. Based on design simulations, not tested in production. b. Sum of sink and source current for GPIOs as shown in Table 27-10 on page 1822. Table 27-10. Maximum GPIO Package Side Assignments Side GPIOs Left PC[4-7], PD[0-3], PQ[0-3], PE[0-3], PK[0-3], PN[4-5], PH[0-3] Bottom Right Top PA[0-7], PF[0-4],PG[0-1], PK[4-7] PM[0-7], PL[0-7], PB[0-3] PC[0-3], PQ[4], PP[0-5], PN[0-5], PJ[0-1], PB[4-5], PE[4-5], PD[4-7] I/O Reliability For typical continuous drive applications, I/O pins configured between 2 mA and 12 mA and operating at -40 to 85°C, meet the standard 10-year lifetime reliability. If a continuous current sink of 18 mA is required, then operation is limited to 0 to 75°C in order to meet the standard 10-year reliability. At 105°C, I/O configured for continuous drive meet the standard 2.5 year lifetime reliability. In typical switching applications (40% switch rate) operating at -40 to 85°C, all I/O configurations except 2 mA meet the standard 10-year lifetime reliability with 50-pF loading. By limiting the capacitive loading to 20 pF for an I/O configured to 2 mA, the 10-year lifetime reliability can be met at -40 to 85°C. In typical switching applications (40% switch rate) operating at 105°C, all I/O configurations except 2 mA meet the standard 2.5-year lifetime reliability. By reducing the capacitive loading to 20 pF with a typical switching rate at 105°C, a 2-mA I/O configuration meets a 2.5 year lifetime reliability. 1822 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.4 Load Conditions Table 27-11 on page 1823 contains the load conditions used for timing measurements. Figure 27-1. Load Conditions pin CL GND Table 27-11. Load Conditions Signals Load Value (CL) EPI0S[35:0] SDRAM interface EPI0S[35:0] General-Purpose interface 30 pF EPI0S[35:0] Host-Bus interface EPI0S[35:0] PSRAM interface 40 pF All other digital I/O signals 50 pF June 18, 2014 1823 Texas Instruments-Production Data Electrical Characteristics 27.5 JTAG and Boundary Scan Table 27-12. JTAG Characteristics Parameter Parameter Parameter Name No. a J1 FTCK TCK operational clock frequency J2 TTCK TCK operational clock period Min Nom Max Unit 0 - 10 MHz 100 - - ns J3 TTCK_LOW TCK clock Low time - tTCK/2 - ns J4 TTCK_HIGH TCK clock High time - tTCK/2 - ns J5 TTCK_R TCK rise time 0 - 10 ns J6 TTCK_F TCK fall time 0 - 10 ns J7 TTMS_SU TMS setup time to TCK rise 8 - - ns J8 TTMS_HLD TMS hold time from TCK rise 4 - - ns J9 TTDI_SU TDI setup time to TCK rise 18 - - ns J10 TTDI_HLD TDI hold time from TCK rise 4 - - ns TCK fall to Data Valid from High-Z, 2-mA drive 13 35 ns TCK fall to Data Valid from High-Z, 4-mA drive 9 26 ns TCK fall to Data Valid from High-Z, 8-mA drive J11 TTDO_ZDV 8 26 ns 10 29 ns 11 13 ns TCK fall to Data Valid from High-Z, 12-mA drive 11 14 ns TCK fall to Data Valid from Data Valid, 2-mA drive 14 20 ns TCK fall to Data Valid from Data Valid, 4-mA drive 10 26 ns TCK fall to Data Valid from High-Z, 8-mA drive with slew rate control - TCK fall to Data Valid from High-Z, 10-mA drive TCK fall to Data Valid from Data Valid, 8-mA drive J12 TTDO_DV 8 21 ns 10 26 ns TCK fall to Data Valid from Data Valid, 10-mA drive 12 14 ns TCK fall to Data Valid from Data Valid, 12-mA drive 12 15 ns TCK fall to High-Z from Data Valid, 2-mA drive 7 16 ns TCK fall to High-Z from Data Valid, 4-mA drive 7 16 ns 7 16 ns 8 19 ns TCK fall to High-Z from Data Valid, 10-mA drive 20 22 ns TCK fall to High-Z from Data Valid, 12-mA drive 20 25 ns TCK fall to Data Valid from Data Valid, 8-mA drive with slew rate control - TCK fall to High-Z from Data Valid, 8-mA drive J13 TTDO_DVZ TCK fall to High-Z from Data Valid, 8-mA drive with slew rate control - a. A ratio of at least 8:1 must be kept between the system clock and TCK. 1824 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 27-2. JTAG Test Clock Input Timing J2 J3 J4 TCK J6 J5 Figure 27-3. JTAG Test Access Port (TAP) Timing TCK J7 TMS TDI J8 J8 TMS Input Valid TMS Input Valid J9 J9 J10 TDI Input Valid J11 TDO J7 J10 TDI Input Valid J12 TDO Output Valid June 18, 2014 J13 TDO Output Valid 1825 Texas Instruments-Production Data Electrical Characteristics 27.6 Power and Brown-Out Table 27-13. Power and Brown-Out Levels Parameter No. Parameter Parameter Name Min Nom Max Unit P1 TVDDA_RISE Analog Supply voltage (VDDA) rise time - - ∞ µs P2 TVDD_RISE P3 a TVDDC_RISE I/O Supply voltage (VDD) rise time - - ∞ µs Core Supply Voltage (VDDC) rise time 10 - 150 µs Power-On Reset Threshold (Rising Edge) 1.98 2.35 2.72 V Power-On Reset Threshold (Falling Edge) 1.84 2.20 2.56 V P4 VPOR Power-On Reset Hysteresis 0.06 0.15 0.24 V P5 VDDA_POK VDDA Power-OK Threshold (Rising Edge) 2.67 2.82 2.97 V P6 VDDA_BOR0 VDDA Brown-Out Reset Threshold 2.71 2.80 2.89 V VDD_POK VDD Power-OK Threshold (Rising Edge) 2.65 2.80 2.90 V P7 VDD Power-OK Threshold (Falling Edge) 2.67 2.76 2.85 V P8 VDD_BOR0 VDD Brown-Out Reset Threshold 2.77 2.86 2.95 V VDDC_POK VDDC Power-OK Threshold (Rising Edge) 0.85 0.95 1.10 V P9 VDDC Power-OK Threshold (Falling Edge) 0.71 0.80 0.85 V a. The MIN and MAX values are based on an external filter capacitor load within the range of CLDO. Please refer to “On-Chip Low Drop-Out (LDO) Regulator” on page 1834 for the CLDO value. 27.6.1 VDDA Levels The VDDA supply has three monitors: ■ Power-On Reset (POR) ■ Power-OK (POK) ■ Brown Out Reset (BOR) The POR monitor is used to keep the analog circuitry in reset until the VDDA supply has reached the correct range for the analog circuitry to begin operating. The POK monitor is used to keep the digital circuitry in reset until the VDDA power supply is at an acceptable operational level. The digital reset is only released when the Power-On Reset has deasserted and all of the Power-OK monitors for each of the supplies indicate that power levels are in operational ranges. The BOR monitor is used to generate a reset to the device or assert an interrupt if the VDDA supply drops below its operational range. Note: VDDA BOR and VDD BOR events are a combined BOR to the system logic, such that if either BOR event occurs, the following bits are affected: ■ BORRIS bit in the Raw Interrupt Status (RIS) register, System Control offset 0x050. See page 261. ■ BORMIS bit in the Masked Interrupt Status and Clear (MISC) register, System Control offset 0x058. This bit is set only if the BORIM bit in the Interrupt Mask Control (IMC) register has been set. See page 263 and page 265. 1826 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller ■ BOR bit in the Reset Cause (RESC) register, System Control offset 0x05C. This bit is set only if either of the BOR events have been configured to initiate a reset. See page 267. In addition, the following bits control both BOR events: ■ BORIM bit in the Interrupt Mask Control (IMC) register, System Control offset 0x054. ■ VDDA_UBOR0 and VDD_UBOR0 bits in the Power-Temperature Cause (PWRTC) register. Please refer to “System Control” on page 220 for more information on how to configure these registers. Figure 27-4 on page 1827 shows the relationship between VDDA, POK, POR and a BOR event. Figure 27-4. Power and Brown-Out Assertions vs VDDA Levels P1 VDDAMIN VDDA P5RISE 27.6.2 POR 1 POK 1 BOR P4 1 P6 P4 0 0 0 VDD Levels The VDD supply has two monitors: ■ Power-OK (POK) ■ Brown Out Reset (BOR) The POK monitor is used to keep the digital circuitry in reset until the VDD power supply is at an acceptable operational level. The digital reset is only released when the Power-On Reset has deasserted and all of the Power-OK monitors for each of the supplies indicate that power levels are June 18, 2014 1827 Texas Instruments-Production Data Electrical Characteristics in operational ranges. The BOR monitor is used to generate a reset to the device or assert an interrupt if the VDD supply drops below its operational range. Note: VDDA BOR and VDD BOR events are a combined BOR to the system logic, such that if either BOR event occurs, the following bits are affected: ■ BORRIS bit in the Raw Interrupt Status (RIS) register, System Control offset 0x050. See page 261. ■ BORMIS bit in the Masked Interrupt Status and Clear (MISC) register, System Control offset 0x058. This bit is set only if the BORIM bit in the Interrupt Mask Control (IMC) register has been set. See page 263 and page 265. ■ BOR bit in the Reset Cause (RESC) register, System Control offset 0x05C. This bit is set only if either of the BOR events have been configured to initiate a reset. See page 267. In addition, the following bits control both BOR events: ■ BORIM bit in the Interrupt Mask Control (IMC) register, System Control offset 0x054. ■ VDDA_UBOR0 and VDD_UBOR0 bits in the Power-Temperature Cause (PWRTC) register. Please refer to “System Control” on page 220 for more information on how to configure these registers. Figure 27-5 on page 1828 shows the relationship between VDD, POK, POR and a BOR event. Figure 27-5. Power and Brown-Out Assertions vs VDD Levels P2 VDDMIN P8 27.6.3 POK 1 BOR VDD P7RISE 1 P7FALL 0 0 VDDC Levels The VDDC supply has one monitor, the Power-OK (POK). The POK monitor is used to keep the digital circuitry in reset until the VDDC power supply is at an acceptable operational level. The digital reset is only released when the Power-On Reset has deasserted and all of the Power-OK monitors for each of the supplies indicate that power levels are in operational ranges. Figure 27-6 on page 1829 shows the relationship between POK and VDDC. 1828 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 27-6. POK Assertion vs VDDC POK VDDC P3 1.2V P9RISE P9FALL 1 0 27.6.4 Response 27.6.4.1 VDD Glitch Response Figure 27-7 on page 1829 shows the response of the BOR and the POR circuit to glitches on the VDD supply. Figure 27-7. POR-BOR VDD Glitch Response 27.6.4.2 VDD Droop Response Figure 27-8 on page 1830 shows the response of the BOR and the POR monitors to a drop on the VDD supply. June 18, 2014 1829 Texas Instruments-Production Data Electrical Characteristics Figure 27-8. POR-BOR VDD Droop Response 1830 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.7 Reset a Table 27-14. Reset Characteristics Parameter No. Parameter R1 TDPORDLY R2 TIRTOUT R3 TBOR0DLY 0.44 - R4 TRSTMIN Minimum RST pulse width - 0.25 /100 R5 TIRHWDLY RST to Internal Reset assertion delay - R6 b TIRSWR Internal reset timeout after software-initiated system reset - R7 TIRWDR Internal reset timeout after Watchdog reset - 2.44 - µs R8 b TIRMFR Internal reset timeout after MOSC failure reset - 2.44 - µs b Parameter Name Min Nom Max Unit Digital POR to Internal Reset assertion c delay 0.44 - 126 µs - 14 16 24.4 - 6400 ms 125 µs - µs 0.85 - µs 2.44 - µs Standard Internal Reset time bd b b Internal Reset time with recovery code repair e (program or erase) c BOR0 to Internal Reset assertion delay g ms f h a. Minimum timings are for reset assertion using PIOSC as a clock source. Maximum timings are for reset assertion using LFIOSC in Deep-Sleep Operation. b. These values are based on simulation. c. Timing values are dependent on the VDD power-down ramp rate. d. This is the delay from the time POR is released until the reset vector is fetched. e. This parameter applies only in situations where a power-loss or brown-out event occurs during an EEPROM program or erase operation, and EEPROM needs to be repaired (which is a rare case). For all other sequences, there is no impact to normal Power-On Reset (POR) timing. This delay is in addition to other POR delays. f. This value represents the maximum internal reset time when the EEPROM reaches its endurance limit. g. Standard operation. h. Deep-Sleep operation with PIOSC powered down. Figure 27-9. Digital Power-On Reset Timing Digital POR R1 R2 Reset (Internal) The digital Power-On Reset is only released when the analog Power-On Reset has deasserted and all of the Power-OK monitors for each of the supplies indicate that power levels are in operational ranges. June 18, 2014 1831 Texas Instruments-Production Data Electrical Characteristics Figure 27-10. Brown-Out Reset Timing BOR R3 R2 Reset (Internal) Figure 27-11. External Reset Timing (RST) R4 RST (Package Pin) R5 R2 Reset (Internal) Figure 27-12. Software Reset Timing Software Reset R6 Reset (Internal) Figure 27-13. Watchdog Reset Timing Watchdog Reset R7 Reset (Internal) 1832 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 27-14. MOSC Failure Reset Timing MOSC Fail Reset R8 Reset (Internal) June 18, 2014 1833 Texas Instruments-Production Data Electrical Characteristics 27.8 On-Chip Low Drop-Out (LDO) Regulator Table 27-15. LDO Regulator Characteristics Parameter Parameter Name Min Nom Max Unit CLDO External filter capacitor size for internal power a supply 2.5 - 4.0 µF ESR Filter capacitor equivalent series resistance 0 - 100 mΩ ESL Filter capacitor equivalent series inductance VLDO LDO output voltage, Run mode IINRUSH Inrush current - - 0.5 nH 1.13 1.2 1.27 V 50 - 250 mA a. The capacitor should be connected as close as possible to pin 115. 1834 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.9 Clocks The following sections provide specifications on the various clock sources and mode. 27.9.1 PLL Specifications The following tables provide specifications for using the PLL. Note: If the integrated Ethernet PHY is used in this device, then FREF_XTAL and FREF_EXT are required to be 25 MHz. Table 27-16. Phase Locked Loop (PLL) Characteristics Parameter Parameter Name Min Nom Max Unit FREF_XTAL Crystal reference 5 - 25 MHz FREF_EXT External clock reference 5 - 25 MHz - - 480 MHz FPLLR FPLLS TREADY a PLL VCO frequency at 1.2V b PLL VCO frequency at 0.9V - - 480 MHz PLL lock time (enabling the PLL) when PLL is transitioning from power down to power up - - 512 * (reference clock period) µs PLL lock time when the PLL VCO frequency is changed (PLL is already enabled) - - 128 * (reference clock period) µs PLL lock time, changing the OSCSRC between MOSC and PIOSC - - 128 * (reference clock period) µs a. PLL frequency is manually calculated using the values in the PLLFREQ0 and PLLFREQ1 registers. b. If the LDO is dropped to 0.9V, the system must be run 1/4 of the maximum frequency at most. The Q value in the PLLFREQ1 register must be set to 0x3 rather than using the PSYSDIV field in the RSCLKCFG register for the divisor. 27.9.1.1 PLL Configuration The PLL is disabled by default during power-on reset and is enabled later by software if required. Software specifies the output divisor to set the system clock frequency and enables the PLL to drive the output. The PLL is controlled using the PLLFREQ0, PLLFREQ1 and PLLSTAT registers. Changes made to these registers do not become active until after the NEWFREQ bit in the RSCLKCFG register is enabled. The clock source for the main PLL is selected by configuring the PLLSRC field in the Run and Sleep Clock Configuration (RSCLKCFG) register. The PLL allows for the generation of system clock frequencies in excess of the reference clock provided. The reference clocks for the PLL are the PIOSC and the MOSC. The PLL is controlled by two registers, PLLFREQ0 and PLLFREQ1. The PLL VCO frequency (fVCO) is determined through the following calculation: fVCO = fIN * MDIV where fIN = fXTAL/(Q+1)(N+1) or fPIOSC/(Q+1)(N+1) MDIV = MINT + (MFRAC / 1024) The Q and N values are programmed in the PLLFREQ1 register. Note that to reduce jitter, MFRAC should be programmed to 0x0. June 18, 2014 1835 Texas Instruments-Production Data Electrical Characteristics When the PLL is active, the system clock frequency (SysClk) is calculated using the following equation: SysClk = fVCO/ (PSYSDIV + 1) The PLL system divisor factor (PSYSDIV) determines the value of the system clock. Table 5-6 on page 237 shows how the system divisor encodings affect the system clock frequency when the fVCO = 480 MHz. Table 27-17. System Divisor Factors for fvco=480 MHz fVCO (MHz)= 480 MHz System Clock (SYSCLK) (MHz) a System Divisors (PSYSDIV +1) 120 4 60 8 48 10 30 16 24 20 12 40 6 80 a. The use of non-integer divisors introduce additional jitter which may affect interface performance. If the main oscillator provides the clock reference to the PLL, the translation provided by hardware and used to program the PLL is available for software in the PLL Frequency n (PLLFREQn) registers (see page 292). The internal translation provides a translation within ± 1% of the targeted PLL VCO frequency. Table 5-7 on page 238 shows the actual PLL frequency and error for a given crystal choice. Table 5-7 on page 238 provides examples of the programming expected for the PLLFREQ0 and PLLFREQ1 registers. The first column specifies the input crystal frequency and the last column displays the PLL frequency given the values of MINT and N, when Q=0. a Table 27-18. Actual PLL Frequency Crystal Frequency (MHz) MINT (Decimal Value) MINT (Hexadecimal Value) N Reference Frequency b (MHz) PLL Frequency (MHz) 5 64 0x40 0x0 5 320 6 160 0x35 0x2 2 320 8 40 0x28 0x0 8 320 10 32 0x20 0x0 10 320 12 80 0x50 0x2 4 320 16 20 0x14 0x0 16 320 18 160 0xA0 0x8 2 320 20 16 0x10 0x0 20 320 24 40 0x28 0x2 8 320 25 64 0x40 0x4 5 320 5 96 0x60 0x0 5 480 6 80 0x50 0x0 6 480 8 60 0x3C 0x0 8 480 1836 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-18. Actual PLL Frequency (continued) Crystal Frequency (MHz) MINT (Decimal Value) MINT (Hexadecimal Value) N Reference Frequency b (MHz) PLL Frequency (MHz) 10 48 0x30 0x0 10 480 12 40 0x28 0x0 12 480 16 30 0x1E 0x0 16 480 18 80 0x50 0x2 6 480 20 24 0x18 0x0 20 480 24 20 0x14 0x0 24 480 25 96 0x60 0x4 5 480 a. For all examples listed, Q=0 b. For a given crystal frequency, N should be chosen such that the reference frequency is within 4 to 30 MHz. 27.9.2 PIOSC Specifications Table 27-19. PIOSC Clock Characteristics Parameter Parameter Name Min Nom Max Unit - - ±4.5% - Factory calibration, -40°C to 3.3 V 2.64 - - V CMOS input high level, when using an external oscillator with 1.8 V ≤ Supply ≤ 3.3 V 0.8 * Supply - - V CMOS input low level, when using an external oscillator with 1.8 V ≤ Supply ≤ 3.63 V - - 0.2 * Supply V CMOS input buffer hysteresis, when using an external oscillator with 1.8 V ≤ Supply ≤ 3.63 V 360 960 1390 mV 30 - 70 % b Total shunt capacitance Crystal effective series resistance, OSCDRV = 0 ESR Min d Oscillator startup time, when using a crystal DCHIBOSC_EXT External single-Ended (Bypass) reference duty cycle e a. The HIB XOSC pins are non-failsafe and must follow the limits detailed in “Non-Power I/O Pins” on page 1851. b. See information below table. c. Crystal ESR specified by crystal manufacturer. d. Oscillator startup time is specified from the time the oscillator is enabled to when it reaches a stable point of oscillation such that the internal clock is valid. e. Only valid for recommended supply conditions. Measured with OSCDRV bit set (high drive strength enabled, 24 pF). f. Specification is relative to the larger of VDD or VBAT. The load capacitors added on the board, C1 and C2, should be chosen such that the following equation is satisfied (see Table 27-22 on page 1837 for typical values). ■ CL = load capacitance specified by crystal manufacturer ■ CL = (C1*C2)/(C1+C2) + CPKG + CPCB ■ CSHUNT = CPKG + CPCB + C0 (total shunt capacitance seen across XOSC0, XOSC1) ■ CPKG, CPCB as measured across the XOSC0, XOSC1 pins excluding the crystal ■ Clear the OSCDRV bit in the Hibernation Control (HIBCTL) register for C1,2 ≤ 18 pF; set the OSCDRV bit for C1,2 > 18 pF. ■ C0 = Shunt capacitance of crystal specified by the crystal manufacturer 27.9.5 Main Oscillator Specifications a Table 27-23. Main Oscillator Input Characteristics Parameter FMOSC Parameter Name Min Parallel resonance frequency FREF_XTAL_BYPASS External clock reference (PLL in BYPASS mode) C1, C2 CPKG c External load capacitance on OSC0, OSC1 pins c Device package stray shunt capacitance 1838 Nom Max Unit 4 b - 25 MHz 0 - 120 MHz 12 - 24 pF - 0.5 - pF June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-23. Main Oscillator Input Characteristics (continued) Parameter CPCB CSHUNT Parameter Name Min Nom Max Unit - 0.5 - pF - 4 de pF de - - 300 Ω de - - 200 Ω - - 130 Ω de - - 120 Ω de - - 100 Ω de - - 50 Ω - OSCPWR - mW - - 18 ms c PCB stray shunt capacitance c Total shunt capacitance Crystal effective series resistance, 4 MHz Crystal effective series resistance, 6 MHz Crystal effective series resistance, 8 MHz ESR Crystal effective series resistance, 12 MHz Crystal effective series resistance, 16 MHz Crystal effective series resistance, 25 MHz DL TSTART f Oscillator output drive level g Oscillator startup time, when using a crystal VIH CMOS input high level, when using an external oscillator 0.65 * VDD - VDD V VIL CMOS input low level, when using an external oscillator GND - 0.35 * VDD V CMOS input buffer hysteresis, when using an external oscillator 150 - - mV External clock reference duty cycle 45 - 55 % VHYS DCOSC_EXT a. Refer to Table 27-50 on page 1871 and Table 27-51 on page 1871 for additional Ethernet crystal requirements. b. 5 MHz is the minimum when using the PLL. c. See information below table. d. Crystal ESR specified by crystal manufacturer. e. Crystal vendors can be contacted to confirm these specifications are met for a specific crystal part number if the vendors generic crystal datasheet show limits outside of these specifications. f. OSCPWR = (2 * pi * FP * CL * 2.5)2 * ESR / 2. An estimation of the typical power delivered to the crystal is based on the CL, FP and ESR parameters of the crystal in the circuit as calculated by the OSCPWR equation. Ensure that the value calculated for OSCPWR does not exceed the crystal's drive-level maximum. g. Oscillator startup time is specified from the time the oscillator is enabled to when it reaches a stable point of oscillation such that the internal clock is valid. The load capacitors added on the board, C1 and C2, should be chosen such that the following equation is satisfied (see Table 27-23 on page 1838 for typical values and Table 27-24 on page 1840 for detailed crystal parameter information). ■ CL = load capacitance specified by crystal manufacturer ■ CL = (C1*C2)/(C1+C2) + CSHUNT ■ CSHUNT = C0 + CPKG + CPCB (total shunt capacitance seen across OSC0, OSC1 crystal inputs) ■ CPKG, CPCB = the mutual caps as measured across the OSC0,OSC1 pins excluding the crystal. ■ C0 = Shunt capacitance of crystal specified by the crystal manufacturer Table 27-24 on page 1840 lists part numbers of crystals that have been simulated and confirmed to operate within the specifications in Table 27-23 on page 1838. Other crystals that have nearly identical crystal parameters can be expected to work as well. In the table below, the crystal parameters labeled C0, C1 and L1 are values that are obtained from the crystal manufacturer. These numbers are usually a result of testing a relevant batch of crystals June 18, 2014 1839 Texas Instruments-Production Data Electrical Characteristics on a network analyzer. The parameters labeled ESR, DL and CL are maximum numbers usually available in the data sheet for a crystal. The table also includes three columns of Recommended Component Values. These values apply to system board components. C1 and C2 are the values in pico Farads of the load capacitors that should be put on each leg of the crystal pins to ensure oscillation at the correct frequency. Rs is the value in kΩ of a resistor that is placed in series with the crystal between the OSC1 pin and the crystal pin. Rs dissipates some of the power so the Max Dl crystal parameter is not exceeded. Only use the recommended C1, C2, and Rs values with the associated crystal part. The values in the table were used in the simulation to ensure crystal startup and to determine the worst case drive level (WC Dl). The value in the WC Dl column should not be greater than the Max Dl Crystal parameter. The WC Dl value can be used to determine if a crystal with similar parameter values but a lower Max Dl value is acceptable. Crystal Spec (Tolerance / Stability) Max Values 0 132 Rs (kΩ) 12 C2 (pF) 12 C1 (pF) 8 CL (pf) 500 Max Dl (µW) 1.00 2.70 598.10 300 ESR (Ω) 30/50 ppm L1 (mH) 4 C1 (fF) 8 x 4.5 C0 (pF) NX8045GB PKG Size Freq (MHz) NX8045GB- Typical Values Recommended Component Values (mm x mm) NDK Holder MFG MFG Part# Crystal Parameters WC Dl (μW) Table 27-24. Crystal Parameters 4.000M-STDCJL-5 FOX FQ1045A-4 2-SMD 10 x 4.5 4 30/30 ppm 1.18 4.05 396.00 150 500 10 14 14 0 103 NDK NX8045GB- NX8045GB 8 x 4.5 5 30/50 ppm 1.00 2.80 356.50 250 500 8 12 12 0 164 NX8045GB 8 x 4.5 6 30/50 ppm 1.30 4.10 173.20 250 500 8 12 12 0 214 5.000M-STDCSF-4 NDK NX8045GB6.000M-STDCSF-4 FOX FQ1045A-6 2-SMD 10 x 4.5 6 30/30 ppm 1.37 6.26 112.30 150 500 10 14 14 0 209 NDK NX8045GB- NX8045GB 8 x 4.5 8 30/50 ppm 1.00 2.80 139.30 200 500 8 12 12 0 277 4-SMD 7x5 8 30/30 ppm 1.95 6.69 59.10 80 500 10 14 14 0 217 8 50/30 ppm 1.82 4.90 85.70 80 500 16 24 24 0 298 7.2 x 5.2 12 10/20 ppm 2.37 8.85 50 500 10 12 12 2.0 a 124 NX3225GA 3.2 x 2.5 12 20/30 ppm 0.70 2.20 81.00 100 200 8 12 12 2.5 147 NX5032GA 12 30/50 ppm 0.93 3.12 56.40 120 500 8 12 12 0 362 8.000M-STDCSF-6 FOX FQ7050B-8 ECS ECS-80-16- HC49/US 12.5 x 4.85 28A-TR Abracon AABMM- ABMM 20.5 12.0000MHz10-D-1-X-T NDK NX3225GA12.000MHZSTD-CRG-2 NDK NX5032GA- 5 x 3.2 12.000MHZLN-CD-1 1840 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-24. Crystal Parameters (continued) Abracon AABMM- 4-SMD ABMM 7.2 x 5.2 30/30 ppm 1.16 4.16 42.30 80 500 10 14 14 WC Dl (μW) Rs (kΩ) C2 (pF) Recommended Component Values C1 (pF) CL (pf) Max Dl (µW) Max Values ESR (Ω) L1 (mH) C1 (fF) Typical Values C0 (pF) 12 Crystal Spec (Tolerance / Stability) 5 x 3.2 PKG Size Freq (MHz) FQ5032B-12 (mm x mm) FOX Holder MFG MFG Part# Crystal Parameters 0 370 a 143 a 16 10/20 ppm 3.00 11.00 9.30 50 500 10 12 12 2.0 HC-49/UP 13.3 x 4.85 16 15/30 ppm 3.00 12.7 50 1000 10 12 12 2.0 139 NX3225GA 3.2 x 2.5 16 20/30 ppm 1.00 2.90 33.90 80 200 8 12 12 2 188 NX5032GA 5 x 3.2 16 30/50ppm 1.02 3.82 25.90 120 500 8 10 10 0 437 ECX-42 4 x 2.5 16 10/10 ppm 1.47 3.90 25.84 60 300 9 12 12 0.5 289 ABMM 7.2 x 5.2 25 10/20 ppm 3.00 11.00 3.70 50 500 10 12 12 2.0 a 158 HC-49/UP 13.3 x 4.85 25 15/30 ppm 3.00 12.8 3.2 40 1000 10 12 12 1.5 a 159 NX3225GA 3.2 x 2.5 25 20/30 ppm 1.10 4.70 8.70 50 200 8 12 12 2 181 10 10 1.0 16.0000MHz10-D-1-X-T Ecliptek ECX-6595- 8.1 16.000M NDK NX3225GA16.000MHZSTD-CRG-2 NDK NX5032GA- b 16.000MHZLN-CD-1 ECS ECS-160-9-42CKM-TR Abracon AABMM25.0000MHz10-D-1-X-T Ecliptek ECX-659325.000M NDK NX3225GA25.000MHZSTD-CRG-2 NX5032GA- NDK 25.000MHZ- a c 216 NX5032GA 5 x 3.2 25 30/50 ppm 1.3 5.1 7.1 70 500 8 12 12 0.75 269 HC3225/4 3.2 x 2.5 25 30/30 ppm 1.58 5.01 8.34 50 500 12 16 16 1 331 4-SMD 5 x 3.2 25 30/30 ppm 1.69 7.92 5.13 50 500 10 14 14 0.5 433 NX5032GA 5 x 3.2 25 20/25 ppm 2.0 6.1 30 350 10 12 12 2.0 c 124 LD-CD-1 AURIS Q-25.000MHC3225/4F-30-30-E-12-TR FOX FQ5032B-25 TXC 7A2570018 6.7 a. RS values as low as 0 Ohms can be used. Using a lower RS value will result in the WC DL to increase towards the Max DL of the crystal. b. Although this ESR value is outside of the recommended crystal ESR maximum for this frequency, this crystal has been simulated to confirm proper operation and is valid for use with this device. c. RS values as low as 500 Ohms can be used. Using a lower RS value will result in the WC DL to increase towards the Max DL of the crystal. June 18, 2014 1841 Texas Instruments-Production Data Electrical Characteristics 27.9.6 System Clock Specification with ADC Operation Table 27-25. System Clock Characteristics with ADC Operation Parameter Fsysadc 27.9.7 Parameter Name Min Nom Max Unit - 16 - MHz System clock frequency when the ADC module is operating (when PLL is bypassed). System Clock Specification with USB Operation Table 27-26. System Clock Characteristics with USB Operation Parameter Fsysusb Parameter Name System clock frequency when the USB module is operating (note that MOSC must be the clock source, either with or without using the PLL) 1842 Min Nom Max Unit 30 - - MHz June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.10 Sleep Modes The following tables can be used to calculate the maximum wake time from Sleep or Deep Sleep depending on the specific application. Depending on the application configuration, each of the parameters, except for TFLASH, add sequential latency to the wake time. Flash restoration happens in parallel to the other wake processes and its wake time is normally absorbed by the other latencies. As an example, the wake time for a device in Deep Sleep, with the PIOSC and PLL turned off and the Flash and SRAM in low power mode is calculated as follows: Wake Time = TPIOSCDS + TPLLDS + TSRAMLPDS TFLASH does not contribute to this equation since all other parameters are greater in value. Note that in Sleep mode the wake time due to a clock source is zero because the device uses the same clock configuration in Run mode; thus, there is no latency involved with respect to the clocks. Table 27-27. Wake from Sleep Characteristics Parameter No Parameter Parameter Name Min Nom Max D1 TPIOSC Time to restore PIOSC as System Clock in Sleep mode - - N/A D2 TMOSC Time to restore MOSC as System Clock in Sleep mode - - N/A D3 TPLL Time to restore PLL as System Clock in Sleep mode - - D4 TLDO D5 TFLASH D6 TSRAMLP D7 TSRAMSTBY Unit a µs b µs N/A c µs Time to restore LDO to 1.2 V in Sleep mode - - 39 µs Time to restore Flash to active state from low power state in Sleep mode - - 5 µs Time to restore SRAM to active state from low power state in Sleep mode - - 15 µs Time to restore SRAM to active state from standby state in Sleep mode - - 15 µs a. Because the PIOSC is enabled in both Run and Sleep Mode for this configuration, no restoration time is required. b. Because the MOSC is enabled in both Run and Sleep Mode for this configuration, no restoration time is required. c. Because the PLL is enabled in both Run and Sleep Mode for this configuration, no restoration time is required. Table 27-28. Wake from Deep Sleep Characteristics Parameter No Parameter Parameter Name Max Unit D8 TPIOSCDS Time to restore PIOSC as System Clock in Deep Sleep Mode - - 14 Deep Sleep a Clock Cycles D9 TMOSCDS Time to restore MOSC as System Clock in Deep Sleep Mode - - 18 ms D10 TPLLDS Time to restore PLL as System Clock in Deep Sleep Mode - - 1 cycle of Deep Sleep Clock + 512 cycles of PLL a reference Clock clocks D11 TLDODS Time to restore LDO to 1.2 V in Deep Sleep Mode - - 39 µs D12 TFLASHLPDS Time to restore Flash to active state from low power state - - 5 µs D13 TSRAMLPDS Time to restore SRAM to active state from low power state - - 15 µs June 18, 2014 Min Nom 1843 Texas Instruments-Production Data Electrical Characteristics Table 27-28. Wake from Deep Sleep Characteristics (continued) Parameter No Parameter Parameter Name D14 TSRAMSTBYDS Time to restore SRAM to active state from standby state Min Nom - - Max Unit 15 µs a. Deep Sleep Clock can vary. See page 281 for the Deep Sleep Clock options. 1844 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.11 Hibernation Module The Hibernation module requires special system implementation considerations because it is intended to power down all other sections of its host device, refer to “Hibernation Module” on page 531. Table 27-29. Hibernation Module Battery Characteristics Parameter VBAT b VBATRMP Parameter Name Min Nominal Max Battery supply voltage 1.8 3.0 3.6 V 0 - 0.7 V/µs Low battery detect voltage, VBATSEL=0x0 1.8 1.9 2.0 V Low battery detect voltage, VBATSEL=0x1 2.0 2.1 2.2 V Low battery detect voltage, VBATSEL=0x2 2.2 2.3 2.4 V Low battery detect voltage, VBATSEL=0x3 2.4 2.5 2.6 V VBAT battery supply voltage ramp time VLOWBAT Unit a a. To ensure proper functionality, any voltage input higher than VBAT Max, must be connected through a diode. b. For recommended VBAT RC circuit values, refer to the diagrams located in“Hibernation Clock Source” on page 535. Table 27-30. Hibernation Module Characteristics Parameter No Parameter H1 TWAKE H2 Parameter Name WAKE assertion time Min Nom Max Unit 100 - - ns - - 1 Hibernation clock period TWAKE_TO_HIB WAKE assert to HIB desassert (wake up time) H3 TVDD_RAMP VDD ramp to 3.0 V - Depends on characteristics of power supply - μs H4 TVDD_CODE VDD at 3.0 V to internal POR deassert; first instruction executes - - 500 μs Duty cycle for RTCCLK output signal, when using a 32.768-kHz crystal 40 - 60 % Duty cycle for RTCCLK output signal, when using a 32.768-kHz external single-ended (bypass) clock source 30 - 70 % H5 DCRTCCLK Table 27-31. Hibernation Module Tamper I/O Characteristics Parameter RTPU Parameter Name Min Nominal Max Unit TMPRn pull-up resistor 3.5 4.4 5.2 MΩ - - TSP TMPRn pulse width with short glitch filter 62 - - µs TLP TMPRn pulse width with long glitch filter 94 - - ms TNMIS TMPRn assertion to NMI (short glitch filter) - - 95 µs TNMIL TMPRn assertion to NMI (long glitch filter) - - 94 ms VBAT*0.8 - - V VIH TMPRn high-level input voltage when operating from VBAT June 18, 2014 1845 Texas Instruments-Production Data Electrical Characteristics Figure 27-15. Hibernation Module Timing H1 WAKE H2 HIB H3 VDD H4 POR 1846 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.12 Flash Memory Table 27-32. Flash Memory Characteristics Parameter PECYC TRET Parameter Name Min Nom Max Unit 100,000 - - cycles 20 - - years 11 - - years 30 100 300 µs Page erase time, 1. b. If programming fewer than 64 bits of data, the programming time is the same. For example, if only 32 bits of data need to be programmed, the other 32 bits are masked off. June 18, 2014 1847 Texas Instruments-Production Data Electrical Characteristics 27.13 EEPROM a Table 27-33. EEPROM Characteristics Parameter b EPECYC ETRET Parameter Name c Number of mass program/erase cycles of a single word Data retention with 100% power-on hours at TJ=85˚C ETRET_EXTEMP Data retention with 10% power-on hours at TJ=125˚C and 90% power-on hours at TJ=100˚C ETPROG ETREAD ETME Min Nom Max Unit 500,000 - - cycles 20 - - years 11 - - years Program time for 32 bits of data with memory space available - 110 600 μs Program time for 32 bits of data in which a copy to the copy buffer is required, the copy buffer has space and less than 10% of EEPROM endurance used - 30 - ms Program time for 32 bits of data in which a copy to the copy buffer is required, the copy buffer has space and greater than 90% of EEPROM endurance used - - 900 ms Program time for 32 bits of data in which a copy of the copy buffer is required, the copy buffer requires an erase and less than 10% of EEPROM endurance used - 60 - ms Program time for 32 bits of data a copy to the copy buffer is required, the copy buffer requires an erase and greater than 90% of EEPROM endurance used - - 1800 ms - 7+ 2*(EWS) d Read access time 9+4*(EWS) system clocks Mass erase time, 0 -> 1. d. The EWS field is programmed in the MEMTIM0 register at Sysctl Offset 0x0C0. 1848 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.14 Input/Output Pin Characteristics Note: All GPIO signals are 3.3-V tolerant, except for PB1 (USB0VBUS) which is 5-V tolerant. See “Signal Description” on page 743 for more information on GPIO configuration. Two types of pads are provided on the device: ■ Fast GPIO pads: These pads provide variable, programmable drive strength and optimized voltage output levels. ■ Slow GPIO pads: These pads provide 2-mA drive strength and are designed to be sensitive to voltage inputs. The following GPIOs port pins are designed with Slow GPIO Pads: – PJ1 Note: Port pins PL6 and PL7 operate as Fast GPIO pads, but have 4-mA drive capability only. GPIO register controls for drive strength, slew rate and open drain have no effect on these pins. The registers which have no effect are as follows: GPIODR2R, GPIODR4R, GPIODR8R, GPIODR12R, GPIOSLR, and GPIOODR. Note: Port pins PM[7:4] operate as Fast GPIO pads but support only 2-, 4-, 6-, and 8-mA drive capability. 10- and 12-mA drive are not supported. All standard GPIO register controls, except for the GPIODR12R register, apply to these port pins. abcd Table 27-34. Fast GPIO Module Characteristics Parameter Parameter Name Min Nom Max Unit - - 50 pF 12.1 16.0 20.2 kΩ 25 - 40 kΩ 13.0 20.5 35.5 kΩ 10 14.3 17 kΩ Fast GPIO input leakage current, 0 V ≤ VIN ≤ VDDGPIO g pins - - 400 nA ILKG+ Fast GPIO input leakage current, 0 V < VIN ≤ VDD, Fast GPIO pins configured as ADC or analog comparator inputs - - 400 nA IINJ- DC injection current, VIN ≤ 0 V - - 60 µA - CLGPIO RGPIOPU Capacitive loading for measurements given in this e table f Fast GPIO internal pull-up resistor RGPIOPU4MA Fast GPIO PL6 and PL7 (4-mA only) pull-up resistor RGPIOPD f Fast GPIO internal pull-down resistor RGPIOPD4MA Fast GPIO PL6 and PL7 (4-mA only) pull-down resistor IMAXINJ- d Max negative injection if not voltage protected - -0.5 mA h 7.85 11.73 ns h 4.15 6.35 ns 2.33 3.73 ns Fast GPIO rise time, 2-mA drive Fast GPIO rise time, 4-mA drive h TGPIOR Fast GPIO rise time, 8-mA drive h Fast GPIO rise time, 8-mA drive with slew rate control - 3.77 5.76 ns h 1.98 3.22 ns h 1.75 2.9 ns Fast GPIO rise time, 10-mA drive Fast GPIO rise time, 12-mA drive June 18, 2014 1849 Texas Instruments-Production Data Electrical Characteristics Table 27-34. Fast GPIO Module Characteristics (continued) Parameter Parameter Name Nom Max Unit i Min Fast GPIO fall time, 2-mA drive 10.3 16.5 ns i 5.15 8.29 ns 2.58 4.16 ns Fast GPIO fall time, 4-mA drive i TGPIOF Fast GPIO fall time, 8-mA drive Fast GPIO fall time, 8-mA drive with slew rate control i - 3.54 5.55 ns Fast GPIO fall time, 10-mA drive i 2.07 3.34 ns i 1.73 2.78 ns Fast GPIO fall time, 12-mA drive a. VDD must be within the range specified in Table 27-6 on page 1820. b. Leakage and Injection current characteristics specified in this table also apply to XOSC0 and XOSC1 inputs. c. Note that for the ADC's external reference inputs, care must be taken to avoid a current limiting resistor (refer to IVREF spec in Table 27-44 on page 1861) d. I/O pads should be protected if at any point the IO voltage has a possibility of going outside the limits shown in the table. If the part is unpowered, the IO pad Voltage or Current must be limited (as shown in this table) to avoid powering the part through the IO pad, causing potential irreversible damage. e. Refer to individual peripheral sections for specific loading information. f. This value includes all GPIO except for port pins PL6 and PL7. g. The leakage current is measured with VIN applied to the corresponding pin(s). The leakage of digital port pins is measured individually. The port pin is configured as an input and the pull-up/pull-down resistor is disabled. h. Time measured from 20% to 80% of VDD. i. Time measured from 80% to 20% of VDD. abc Table 27-35. Slow GPIO Module Characteristics Parameter CLGPIO Parameter Name Capacitive loading for measurements given in this d table Min Nom Max Unit - - 50 pF RGPIOPU Slow GPIO internal pull-up resistor 13.8 20.0 31.4 kΩ RGPIOPD Slow GPIO internal pull-down resistor 13.0 20.5 35.5 kΩ Slow GPIO input leakage current, 0 V ≤ VIN ≤ VDD e GPIO pins - - 3.25 nA ILKG+ Slow GPIO input leakage current, 0 V < VIN ≤ VDD, GPIO pins configured as ADC or analog comparator inputs - - 3.25 nA IINJ- DC injection current, VIN ≤ 0 V - - 3.42 µA f TGPIOR Slow GPIO rise time, 2-mA drive - 19.3 29.8 ns TGPIOF Slow GPIO fall time, 2-mA drive g - 12.8 21.1 ns a. VDD must be within the range specified in Table 27-6 on page 1820. b. VIN must be within the range specified in Table 27-1 on page 1818. Leakage current outside of this maximum voltage is not guaranteed and can result in permanent damage of the device. c. To avoid potential damage to the part, either the voltage or current on the non-Power, non-WAKE input/outputs should be limited externally as shown in this table. d. Refer to individual peripheral sections for specific loading information. e. The leakage current is measured with VIN applied to the corresponding pin(s). The leakage of digital port pins is measured individually. The port pin is configured as an input and the pull-up/pull-down resistor is disabled. f. Time measured from 20% to 80% of VDD. g. Time measured from 80% to 20% of VDD. 1850 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.14.1 Types of I/O Pins and ESD Protection Caution – All device I/Os pins, except for PB1, are NOT 5V tolerant; voltages in excess of the limits shown in Table 27-6 on page 1820 can permanently damage the device. PB1 is used for the USB's USB0VBUS signal, which requires a 5-V input. 27.14.1.1 Hibernate WAKE pin The Hibernate WAKE pin uses ESD protection, similar to the one shown in Figure 27-16 on page 1851. This ESD protection prevents a direct path between this pad and any power supply rails in the device. The WAKE pad input voltage should be kept inside the maximum ratings specified in Table 27-1 on page 1818 to ensure current leakage and current injections are within acceptable range. Current leakages and current injection for these pins are specified in Table 27-36 on page 1851. Figure 27-16. ESD Protection ab Table 27-36. Pad Voltage/Current Characteristics for Hibernate WAKE Pin Parameter ILKG+ ILKG- Parameter Name Min Nom Max Unit - - 300 nA - - 43.3 µA - - 2 mA - - -0.5 mA Positive IO leakage for VDD ≤ VIN ≤VBAT + 0.3V c Negative IO leakage for-0.3V ≤ VIN ≤0V d IINJ+ Max positive injection if not voltage protected IINJ- Max negative injection if not voltage protected d a. VIN must be within the range specified in Table 27-1 on page 1818. Leakage current outside of this maximum voltage is not guaranteed and can result in permanent damage of the device. b. VDD must be within the range specified in Table 27-6 on page 1820. c. Leakage outside the minimum range (-0.3V) is unbounded and must be limited to IINJ- using an external resistor. d. If the I/O pad is not voltage limited, it should be current limited (to IINJ+ and IINJ-) if there is any possibility of the pad voltage exceeding the VIO limits (including transient behavior during supply ramp up, or at any time when the part is unpowered). 27.14.1.2 Non-Power I/O Pins Most non-power I/Os (with the exception of the I/O pad for Hibernate WAKE input) have ESD protection as shown in Figure 27-17 on page 1852. These I/Os have an ESD clamp to ground and a diode connection to the corresponding power supply rail. The voltage and current of these I/Os should follow the specifications in Table 27-37 on page 1852 to prevent potential damage to the device. In addition, it is recommended that the ADC external reference specifications in Table 27-44 on page 1861 be adhered to prevent any gain error. June 18, 2014 1851 Texas Instruments-Production Data Electrical Characteristics Figure 27-17. ESD Protection for Non-Power Pins (Except WAKE Signal) Table 27-37. Non-Power I/O Pad Voltage/Current Characteristics Parameter d VIO Parameter Name IO pad voltage limits if voltage protected Min Nom Max Unit -0.3 VDD VDD+0.3 V e - - 400 nA e - - 60 µA - - 2 mA - - -0.5 mA ILKG+ Positive IO leakage for VDD ≤ VIN ≤VIO MAX ILKG- Negative IO leakage for VIO MIN ≤ VIN ≤ 0V IINJ+ Max positive injection if not voltage protected IINJ- abc f f Max negative injection if not voltage protected a. To avoid potential damage to the part, either the voltage or current on the non-Power, non-WAKE input/outputs should be limited externally as shown in this table. b. Note that for the ADC's external reference inputs, care must be taken to avoid a current limiting resistor (refer to IVREF spec in Table 27-44 on page 1861) c. I/O pads should be protected if at any point the IO voltage has a possibility of going outside the limits shown in the table. If the part is unpowered, the IO pad Voltage or Current must be limited (as shown in this table) to avoid powering the part through the IO pad, causing potential irreversible damage. d. The Hibernate XOSC pins are non-failsafe and should follow the limits for VIO with respect to both VDD and VBAT. Thus VIO for the HIB XOSC pins should also fall within a MIN of -0.3 and a MAX of VBAT + 0.3. e. MIN and MAX leakage current for the case when the I/O is voltage protected to VIO Min or VIO Max. f. If the I/O pad is not voltage limited, it should be current limited (to IINJ+ and IINJ-) if there is any possibility of the pad voltage exceeding the VIO limits (including transient behavior during supply ramp up, or at any time when the part is unpowered). 1852 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.15 External Peripheral Interface (EPI) Table 27-38. EPI Interface Load Conditions Signals Load Value (CL) EPI0S[35:0] SDRAM interface EPI0S[35:0] General-Purpose interface 30 pF EPI0S[35:0] Host-Bus interface EPI0S[35:0] PSRAM interface 40 pF When the EPI module is in SDRAM mode, EPI CLK must be configured to 12 mA. The EPI data bus can be configured to 8 mA. Table 27-39 on page 1853 shows the rise and fall times in SDRAM mode. When the EPI module is in Host-Bus or General-Purpose mode, the values in “Input/Output Pin Characteristics” on page 1849 should be used. Table 27-39. EPI SDRAM Characteristics Parameter Parameter Name Condition Min Nom Max Unit TSDRAMR EPI Rise Time (from 20% to 80% of VDD) 12-mA drive, CL = 30 pF - 2 3 ns TSDRAMF EPI Fall Time (from 80% to 20% of VDD) 12-mA drive, CL = 30 pF - 2 3 ns a Table 27-40. EPI SDRAM Interface Characteristics Parameter No Parameter Min Nom Max Unit E1 TCK SDRAM Clock period Parameter Name 16.67 - - ns E2 TCH SDRAM Clock high time 8.33 - - ns E3 TCL SDRAM Clock low time 8.33 - - ns E4 TCOV CLK to output valid - - 4 ns E5 TCOI CLK to output invalid - - 4 ns E6 TCOT CLK to output tristate E7 TS Input set up to CLK E8 TH CLK to input hold - - 4 ns 8.5 - - ns 0 - - ns E9 TPU Power-up time 100 - - µs E10 TRP Precharge all banks 20 - - ns E11 TRFC Auto refresh 66 - - ns E12 TMRD Program mode register 2 - - EPI CLK a. The EPI SDRAM interface must use 12-mA drive. June 18, 2014 1853 Texas Instruments-Production Data Electrical Characteristics Figure 27-18. SDRAM Initialization and Load Mode Register Timing CLK (EPI0S31) E1 CKE (EPI0S30) E2 E3 NOP Command (EPI0S[29:28,19:18]) NOP NOP NOP AREF PRE NOP NOP PRE LOAD AREF NOP AREF Active DQMH, DQML (EPI0S[17:16]) AD11, AD[9:0] (EPI0S[11,9:0] Code Row All Banks AD10 (EPI0S[10]) Code Row Single Bank BAD[1:0] (EPI0S[14:13]) Bank AD [15,12] (EPI0S [15,12]) E9 E10 E11 E12 Notes: 1. If CS is high at clock high time, all applied commands are NOP. 2. The Mode register may be loaded prior to the auto refresh cycles if desired. 3. JEDEC and PC100 specify three clocks. 4. Outputs are guaranteed High-Z after command is issued. Figure 27-19. SDRAM Read Timing CLK (EPI0S31) CKE (EPI0S30) E4 E5 E6 CSn (EPI0S29) WEn (EPI0S28) RASn (EPI0S19) CASn (EPI0S18) E7 DQMH, DQML (EPI0S [17:16]) AD [15:0] (EPI0S [15:0]) Row Activate Column NOP Read E8 Data 0 Data 1 ... Data n Burst Term NOP AD [15:0] driven in AD [15:0] driven out AD [15:0] driven out 1854 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 27-20. SDRAM Write Timing CLK (EPI0S31) CKE (EPI0S30) E4 E5 E6 CSn (EPI0S29) WEn (EPI0S28) RASn (EPI0S19) CASn (EPI0S18) DQMH, DQML (EPI0S [17:16]) AD [15:0] (EPI0S [15:0]) Row Column-1 Activate NOP Data 0 Data 1 ... Data n Burst Term Write AD [15:0] driven out AD [15:0] driven out Table 27-41. EPI Host-Bus 8 and Host-Bus 16 Interface Characteristics Parameter No Parameter E14 TISU Parameter Name Min Nom Max Unit Read data set up time 10 - - ns E15 TIH Read data hold time 0 - - ns E16 TDV WRn to write data valid - - 3.6 ns E17 TDI Data hold from WRn invalid 1 - - EPI Clocks E18 TOV ALE/CSn to output valid - - 4 ns CSn to output invalid - - 4 ns WRn / RDn strobe width low 1 - - EPI Clocks E19 TOINV E20 TSTLOW E21 TALEHIGH ALE width high - 1 - EPI Clocks E22 TCSLOW CSn width low 2 - - EPI Clocks E23 TALEST ALE rising to WRn / RDn strobe falling 2 - - EPI Clocks E24 TALEADD ALE falling to Address tristate 1 - - EPI Clocks June 18, 2014 1855 Texas Instruments-Production Data Electrical Characteristics Figure 27-21. Host-Bus 8/16 Asynchronous Mode Read Timing E21 ALE (EPI0S30) CSn (EPI0S30) E18 E22 WRn (EPI0S29) E19 E23 E20 RDn/OEn (EPI0S28) BSEL0n/ BSEL1na Address E15 E14 Data a Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. Figure 27-22. Host-Bus 8/16 Asynchronous Mode Write Timing E21 ALE (EPI0S30) E18 E22 CSn (EPI0S30) E18 E19 E20 WRn (EPI0S29) E23 RDn/Oen (EPI0S28) BSEL0n BSEL1na Address E16 Data a E17 Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. 1856 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 27-23. Host-Bus 8/16 Mode Asynchronous Muxed Read Timing E21 ALE (EPI0S30) E18 CSn (EPI0S30) E22 WRn (EPI0S29) E19 E18 E23 E20 RDn/OEn (EPI0S28) E24 BSEL0n/ BSEL1na a E15 E14 Muxed Address/Data Address Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. Figure 27-24. Host-Bus 8/16 Mode Asynchronous Muxed Write Timing E21 ALE (EPI0S30) E18 E22 CSn (EPI0S30) E18 E19 E20 WRn (EPI0S29) E23 RDn/Oen (EPI0S28) BSEL0n BSEL1na E16 Muxed Address/Data a Address Data BSEL0n and BSEL1n are available in Host-Bus 16 mode only. Table 27-42. EPI General-Purpose Interface Characteristics Parameter No Parameter Parameter Name Min Nom Max Unit E25 TCK General-Purpose Clock period 16.67 - - ns E26 TCH General-Purpose Clock high time 8.33 - - ns E27 TCL General-Purpose Clock low time 8.33 - - ns E28 TISU Input signal set up time to rising clock edge 8.50 - - ns E29 TIH Input signal hold time from rising clock edge 0 - - ns E30 TDV Falling clock edge to output valid - - 4 ns - - 4 ns 8.5 - - ns E31 TDI E32 TRDYSU Falling clock edge to output invalid iRDY assertion or deassertion set up time to falling clock edge June 18, 2014 1857 Texas Instruments-Production Data Electrical Characteristics Figure 27-25. General-Purpose Mode Read and Write Timing E26 E25 E27 Clock (EPI0S31) E30 Frame (EPI0S30) RD (EPI0S29) WR (EPI0S28) Address E30 E28 Data Data E31 Data E29 Read Note: Write This figure illustrates accesses where the FRM50 bit is clear, the FRMCNT field is 0x0 and the WR2CYC bit is clear. Table 27-43. EPI PSRAM Interface Characteristics Parameter No Parameter E33 TEPICLK E34 TRTFT E35 TOV E36 E37 Parameter Name Min Nom Max Unit 20 - - ns - - 1.8 ns Falling EPI_CLK to Address/Write Data or a Control output valid 4.5 - 20 ns THT Falling EPI_CLK to Address/Write Data or a Control hold time 2 - - ns TSUP Read data setup time from EPI_CLK rising - - 9 ns EPI_CLK period EPI_CLK rise or fall time E38 TDH Read data output hold from EPI_CLK rising 0 - - ns E39 TIRV iRDY setup time - - 9 ns E40 TIRH iRDY hold time - - 9 ns a. Control output includes WRn, RDn, OEn, BSELn, ALE, and CSn. 1858 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 27-26. PSRAM Single Burst Read E34 E33 EPICLK EPI0S31 E35 EPI0S[19:0] E36 ADDRESS ALE E36 CSn E36 WRn EPI0S29 BSELn E39 E40 iRDY EPI0S32 EPI0S[15:0] DATA E37 E38 June 18, 2014 1859 Texas Instruments-Production Data Electrical Characteristics Figure 27-27. PSRAM Single Burst Write E33 E34 EPICLK EPI0S31 E35 EPI0S[19:0] E36 ADDRESS ALE E35 BSELn E36 CSn WRn EPI0S29 E39 E40 iRDY EPI0S32 E35 EPI0S[15:0] E36 DATA DATA 1860 DATA DATA June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.16 Analog-to-Digital Converter (ADC) ab Table 27-44. ADC Electrical Characteristics for ADC at 1 Msps Parameter Parameter Name Min Nom Max Unit POWER SUPPLY REQUIREMENTS VDDA ADC supply voltage 2.97 3.3 3.63 V GNDA ADC ground voltage - 0 - V - 1.0 // 0.01 - μF VDDA / GNDA VOLTAGE REFERENCE CREF Voltage reference decoupling capacitance c EXTERNAL VOLTAGE REFERENCE INPUT VREFA+ Positive external voltage reference for ADC, when VREF field in the ADCCTL register is 0x1- 2.4 VDDA VDDA V IVREF Current on VREF+ input, using external VREF+ = 3.3 V - 330.5 440 µA ILVREF DC leakage current on VREF+ input when external VREF disabled - - 2.0 µA CREF External reference decoupling capacitance - 1.0 // 0.01 - μF 0 - VDDA V Differential, full-scale analog input voltage, df internal reference -VDDA - VVDDA V Single-ended, full-scale analog input voltage, e external reference GNDA - VREFA+ V - (VREFA+ GNDA) - VREFA+ GNDA V - - [(VREFA+ + VREFA-) / 2] ± 0.025 V - - 2.0 µA - - 2.5 kΩ - - 10 pF - - 500 Ω - 16 - MHz c ANALOG INPUT Single-ended, full- scale analog input voltage, de internal reference VADCIN Differential, full-scale analog input voltage, g external reference VINCM IL h Input common mode voltage, differential mode i ADC input leakage current i RADC ADC equivalent input resistance CADC ADC equivalent input capacitance RS i i Analog source resistance SAMPLING DYNAMICS j FADC ADC conversion clock frequency FCONV ADC conversion rate 1 TS ADC sample time TC ADC conversion time TLT Latency from trigger to start of conversion k Msps - 250 - ns - 1 - µs - 2 - ADC clocks lm SYSTEM PERFORMANCE when using external reference N INL DNL Resolution 12 Integral nonlinearity error, over full input range - ±1.5 bits ±3.0 LSB n Differential nonlinearity error, over full input range - ±0.8 +2.0/-1.0 LSB EO Offset error - ±1.0 ±3.0 LSB EG Gain error o - ±2.0 ±3.0 LSB June 18, 2014 1861 Texas Instruments-Production Data Electrical Characteristics Table 27-44. ADC Electrical Characteristics for ADC at 1 Msps (continued) Parameter ET Parameter Name p Total unadjusted error, over full input range Min Nom Max Unit - ±2.5 ±4.0 LSB LSB SYSTEM PERFORMANCE when using internal reference N Resolution 12 bits INL Integral nonlinearity error, over full input range - ±1.5 ±3.0 DNL Differential nonlinearity error, over full input range - ±0.8 +2.0/-1.0 LSB EO Offset error - ±5.0 ±15.0 LSB EG o Gain error - ±10.0 ±30.0 LSB ET Total unadjusted error, over full input range - ±10.0 ±30.0 LSB p n qr DYNAMIC CHARACTERISTICS SNRD Signal-to-noise-ratio, Differential input, VADCIN: s -20dB FS, 1KHz 70 72 - dB SDRD Signal-to-distortion ratio, Differential input, stu VADCIN: -3dB FS, 1KHz 72 75 - dB SNDRD Signal-to-Noise+Distortion ratio, Differential svw input, VADCIN: -3dB FS, 1KHz 68 70 - dB Signal-to-noise-ratio, Single-ended input, VADCIN: -20dB FS, 1KHz 60 65 - dB SDRS Signal-to-distortion ratio, Single-ended input, tu VADCIN: -3dB FS, 1KHz 70 72 - dB SNDRS Signal-to-Noise+Distortion ratio, Single-ended xvw input, VADCIN: -3dB FS, 1KHz 60 63 - dB SNRS x TEMPERATURE SENSOR VTSENS Temperature sensor voltage, junction temperature 25 °C - 1.633 - V STSENS Temperature sensor slope at: - -13.3 - mV/°C - - ±5 °C -40°C to 85 °C ambient (industrial temperature part) -40°C to 105 °C ambient (extended temperature part) ETSENS y Temperature sensor accuracy at: -40°C to 85 °C ambient (industrial temperature part) -40°C to 105 °C ambient (extended temperature part) a. Values are at VREF+= 3.3V, FADC=16 MHz unless otherwise noted. b. Best design practices suggest that static or quiet digital I/O signals be configured adjacent to sensitive analog inputs to reduce capacitive coupling and cross talk. Unexpected results can occur if a switching digital I/O is placed adjacent to an ADC input channel or voltage reference input. In addition, analog signals configured adjacent to ADC input channels or reference inputs must meet the RADC equivalent input resistance given in this table and must be band-limited to 100 kHz or lower. c. Two capacitors in parallel. Note that these capacitors should be as close to the die as possible. d. Internal reference is connected directly between VDDA and GNDA (VREFi = VDDA - GNDA). In this mode, EO, EG, ET, and dynamic specifications are adversely affected due to internal voltage drop and noise on VDDA and GNDA. Internal reference voltage is selected when VREF field in the ADCCTL register is 0x0. e. VADCIN = VINP - VINN f. With signal common mode as VDDA/2. 1862 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller g. With signal common mode as (VREF+ + GNDA). h. This parameter is defined as the average of the differential inputs. i. As shown in Figure 27-29 on page 1866, RADC is the total equivalent resistance in the input line all the way up to the sampling node at the input of the ADC. j. See “System Clock Specification with ADC Operation” on page 1842 for full ADC clock frequency specification. k. ADC conversion time (Tc) includes the ADC sample time (Ts). l. Low noise environment is assumed in order to obtain values close to spec. Board must have good ground isolation between analog and digital grounds, a clean reference voltage is assumed, and input signal must be bandlimited to Nyquist bandwidth. No anti-aliasing filter is provided internally. m. ADC static measurements taken by averaging over several samples. At least 20-sample averaging is assumed to obtain expected typical or maximum spec values. n. 12-bit DNL o. Gain error is measured at max code after compensating for offset. Gain error is equivalent to "Full Scale Error." It can be given in % of slope error, or in LSB, as done here. p. Total Unadjusted Error is the maximum error at any one code versus the ideal ADC curve. It includes all other errors (offset error, gain error and INL) at any given ADC code. q. A low noise environment is assumed in order to obtain values close to spec. The board must have good ground isolation between analog and digital grounds and a clean reference voltage. The input signal must be band-limited to Nyquist bandwidth. No anti-aliasing filter is provided internally. r. ADC dynamic characteristics are measured using low-noise board design, with low-noise reference voltage ( < -74dB noise level in signal BW) and low-noise analog supply voltage. Board noise and ground bouncing couple into the ADC and affect dynamic characteristics. Clean external reference must be used to achieve shown specs. s. Differential signal with correct common mode, applied between two ADC inputs. t. SDR = -THD in dB. u. For higher frequency inputs, degradation in SDR should be expected. v. SNDR = S/(N+D) = SINAD (in dB) w. Effective number of bits (ENOB) can be calculated from SNDR: ENOB = (SNDR - 1.76) / 6.02. x. Single ended inputs are more sensitive to board and trace noise than differential inputs; SNR and SNDR measurements on single-ended inputs are highly dependent on how clean the test set-up is. If the input signal is not well-isolated on the board, higher noise than specified could potentially be seen at the ADC output. y. Note that this parameter does not include ADC error. ab Table 27-45. ADC Electrical Characteristics for ADC at 2 Msps Parameter Parameter Name Min Nom Max Unit POWER SUPPLY REQUIREMENTS VDDA ADC supply voltage 2.97 3.3 3.63 V GNDA ADC ground voltage - 0 - V - 1.0 // 0.01 - μF 2.4 VDDA VDDA V VDDA / GNDA VOLTAGE REFERENCE CREF Voltage reference decoupling capacitance c EXTERNAL VOLTAGE REFERENCE INPUT VREFA+ Positive external voltage reference for ADC, when VREF field in the ADCCTL register is d 0x1 - IVREF Current on VREF+ input, using external VREF+ = 3.3 V - 330.5 440 µA ILVREF DC leakage current on VREF+ input when external VREF disabled - - 2.0 µA CREF External reference decoupling capacitance - 1.0 // 0.01 - μF d c ANALOG INPUT June 18, 2014 1863 Texas Instruments-Production Data Electrical Characteristics Table 27-45. ADC Electrical Characteristics for ADC at 2 Msps (continued) Parameter Parameter Name Min Nom Max Unit 0 - VDDA V Differential, full-scale analog input voltage, eg internal reference -VDDA - VVDDA V Single-ended, full-scale analog input voltage, df external reference VREFA- - VREFA+ V - (VREFA+ VREFA-) - VREFA+ - VREFA- V - - [(VREFA+ + VREFA-) / 2] ± 0.025 V - - 2.0 µA - - 2.5 kΩ Single-ended, full- scale analog input voltage, ef internal reference VADCIN Differential, full-scale analog input voltage, dh external reference VINCM IL RADC CADC RS i Input common mode voltage, differential mode j ADC input leakage current j ADC equivalent input resistance j ADC equivalent input capacitance j Analog source resistance - - 10 pF - - 250 Ω - 32 SAMPLING DYNAMICS k FADC ADC conversion clock frequency FCONV ADC conversion rate TS - MHz 2 ADC sample time l Msps - 125 - ns TC ADC conversion time - 0.5 - µs TLT Latency from trigger to start of conversion - 2 - ADC clocks LSB mn SYSTEM PERFORMANCE when using external reference N Resolution 12 bits INL Integral nonlinearity error, over full input range - ±1.5 ±3.0 DNL Differential nonlinearity error, over full input range - ±0.8 +2.0/-1.0 LSB EO Offset error - ±1.0 ±3.0 LSB EG p Gain error - ±2.0 ±3.0 LSB ET Total unadjusted error, over full input range - ±2.5 ±4.0 LSB LSB q o SYSTEM PERFORMANCE when using internal reference N Resolution 12 bits INL Integral nonlinearity error, over full input range - ±1.5 ±3.0 DNL Differential nonlinearity error, over full input range - ±0.8 +2.0/-1.0 LSB EO Offset error - ±5.0 ±15.0 LSB EG p Gain error - ±10.0 ±30.0 LSB ET Total unadjusted error, over full input range - ±10.0 ±30.0 LSB q o rs DYNAMIC CHARACTERISTICS SNRD Signal-to-noise-ratio, Differential input, VADCIN: t -20dB FS, 1KHz 68 72 - dB SDRD Signal-to-distortion ratio, Differential input, tuv VADCIN: -3dB FS, 1KHz 70 75 - dB SNDRD Signal-to-Noise+Distortion ratio, Differential twx input, VADCIN: -3dB FS, 1KHz 65 70 - dB 1864 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-45. ADC Electrical Characteristics for ADC at 2 Msps (continued) Parameter Min Nom Max Unit Signal-to-noise-ratio, Single-ended input, VADCIN: -20dB FS, 1KHz 58 65 - dB SDRS Signal-to-distortion ratio, Single-ended input, uv VADCIN: -3dB FS, 1KHz 68 72 - dB SNDRS Signal-to-Noise+Distortion ratio, Single-ended ywx input, VADCIN: -3dB FS, 1KHz 58 63 - dB SNRS Parameter Name y a. Values are at VREF+= 3.3V, FADC=32 MHz unless otherwise noted. b. Best design practices suggest that static or quiet digital I/O signals be configured adjacent to sensitive analog inputs to reduce capacitive coupling and cross talk. Unexpected results can occur if a switching digital I/O is placed adjacent to an ADC input channel or voltage reference input. In addition, analog signals configured adjacent to ADC input channels or reference inputs must meet the RADC equivalent input resistance given in this table and must be band-limited to 100 kHz or lower. c. Two capacitors in parallel. Note that these capacitors should be as close to the die as possible. d. Assumes external filtering network between VREFA+ and VREFA- as shown in Figure 27-28 on page 1866. External reference noise level must be under 12bit (-74 dB) of Full Scale input, over input bandwidth, measured at VREFA+ - VREFA-. e. Internal reference is connected directly between VDDA and GNDA (VREFi = VDDA - GNDA). In this mode, EO, EG, ET, and dynamic specifications are adversely affected due to internal voltage drop and noise on VDDA and GNDA. Internal reference voltage is selected when VREF field in the ADCCTL register is 0x0. f. VADCIN = VINP - VINN g. With signal common mode as VDDA/2. h. With signal common mode as (VREF+ + VREF-)/2. i. This parameter is defined as the average of the differential inputs. j. As shown in Figure 27-29 on page 1866, RADC is the total equivalent resistance in the input line all the way up to the sampling node at the input of the ADC. k. See “System Clock Specification with ADC Operation” on page 1842 for full ADC clock frequency specification. l. ADC conversion time (Tc) includes the ADC sample time (Ts). m. Low noise environment is assumed in order to obtain values close to spec. Board must have good ground isolation between analog and digital grounds, a clean reference voltage is assumed, and input signal must be bandlimited to Nyquist bandwidth. No anti-aliasing filter is provided internally. n. ADC static measurements taken by averaging over several samples. At least 20-sample averaging is assumed to obtain expected typical or maximum spec values. o. 12-bit DNL p. Gain error is measured at max code after compensating for offset. Gain error is equivalent to "Full Scale Error." It can be given in % of slope error, or in LSB, as done here. q. Total Unadjusted Error is the maximum error at any one code versus the ideal ADC curve. It includes all other errors (offset error, gain error and INL) at any given ADC code. r. A low noise environment is assumed in order to obtain values close to spec. The board must have good ground isolation between analog and digital grounds and a clean reference voltage. The input signal must be band-limited to Nyquist bandwidth. No anti-aliasing filter is provided internally. s. ADC dynamic characteristics are measured using low-noise board design, with low-noise reference voltage ( < -74dB noise level in signal BW) and low-noise analog supply voltage. Board noise and ground bouncing couple into the ADC and affect dynamic characteristics. Clean external reference must be used to achieve shown specs. t. Differential signal with correct common mode, applied between two ADC inputs. u. SDR = -THD in dB. v. For higher frequency inputs, degradation in SDR should be expected. w. SNDR = S/(N+D) = SINAD (in dB) x. Effective number of bits (ENOB) can be calculated from SNDR: ENOB = (SNDR - 1.76) / 6.02. y. Single ended inputs are more sensitive to board and trace noise than differential inputs; SNR and SNDR measurements on single-ended inputs are highly dependent on how clean the test set-up is. If the input signal is not well-isolated on the board, higher noise than specified could potentially be seen at the ADC output. June 18, 2014 1865 Texas Instruments-Production Data Electrical Characteristics Figure 27-28. ADC External Reference Filtering Tiva™ Microcontroller IVREF VREF+ VREF+ CREF GNDA VREF GNDA Figure 27-29. ADC Input Equivalency Tiva™ Microcontroller VDD Zs Rs VS Input PAD Equivalent Circuit ZADC RADC Pin Cs VADCIN ESD Clamp 12-bit SAR ADC Converter 12-bit Word IL Pin Input PAD Equivalent Circuit Pin Input PAD Equivalent Circuit RADC RADC CADC 1866 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.17 Synchronous Serial Interface (SSI) Table 27-46. SSI Characteristics Parameter No. Parameter Parameter Name S1 TCLK_PER S2 TCLK_HIGH S3 TCLK_LOW S4 TCLKR SSIClk rise time S5 TCLKF c S6 TTXDMOV S7 a SSIClk cycle time, as master Min Nom Max Unit 16.67 - - ns b SSIClk cycle time, as slave 100 - - ns SSIClk high time, as master 8.33 - - ns SSIClk high time, as slave 50 - - ns SSIClk low time, as master 8.33 - - ns 50 - - ns 1.25 - - ns 1.25 - - ns Master Mode: Master Tx Data Output (to slave) Valid Time from edge of SSIClk - - 4.00 ns TTXDMOH Master Mode: Master Tx Data Output (to slave) Hold Time after next SSIClk 0.60 - - ns S8 TRXDMS Master Mode: Master Rx Data In (from slave) setup time 7.89 - - ns S9 TRXDMH Master Mode: Master Rx Data In (from slave) hold time 0 - - ns S10 TTXDSOV Slave Mode: Master Tx Data Output (to Master) Valid Time from edge of SSIClk - - 47.60 ns S11 TTXDSOH Slave Mode: Slave Tx Data Output (to Master) Hold Time from next SSIClk 37.4 - - ns S13 TRXDSSU Slave Mode: Rx Data In (from master) setup time - - ns - - ns S14 TRXDSH SSIClk low time, as slave c SSIClk fall time Slave Mode: Rx Data In (from master) hold time e 0 f 37.03 d a. In master mode, the system clock must be at least twice as fast as the SSIClk. b. In slave mode, the system clock must be at least 12 times faster than the SSIClk. c. Note that the delays shown are using 12-mA drive strength. d. This MAX value is for the minimum slave mode TSYSCLK period (8.33 ns). To find the MAX TTXDSOV value for a larger TSYSCLK, use the equation: 4*TSYSCLK+14.25. e. This MIN value is for the minimum slave mode TSYSCLK (8.33 ns). To find the MIN TTXDSOH value for a larger TSYSCLK, use the equation: 4*TSYSCLK+4.08. f. This MIN value is for the minimum slave mode TSYSCLK (8.33 ns). To find the MIN TTXDSH value for a larger TSYSCLK, use the equation: 4*TSYSCLK+3.70. June 18, 2014 1867 Texas Instruments-Production Data Electrical Characteristics Figure 27-30. SSI Timing for TI Frame Format (FRF=01), Single Transfer Timing Measurement S1 S2 S4 S5 SSIClk S3 SSIFss SSITx SSIRx MSB LSB 4 to 16 bits Figure 27-31. Master Mode SSI Timing for SPI Frame Format (FRF=00), with SPH=1 S1 S5 S2 S4 SSIClk (SPO=1) S3 SSIClk (SPO=0) S7 S6 SSITx (to slave) MSB S8 SSIRx ( from slave) LSB S9 MSB LSB SSIFss 1868 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Figure 27-32. Slave Mode SSI Timing for SPI Frame Format (FRF=00), with SPH=1 S1 S5 S2 S4 SSIClk (SPO=1) S3 S3 SSIClk (SPO=0) S10 SSITx S11 MSB (to master) LSB S12 S13 SSIRx MSB ( from master) LSB SSIFss a Table 27-47. Bi- and Quad-SSI Characteristics Parameter No. Parameter Parameter Name b Min Nom Max Unit S15 TCLK_PER SSIClk cycle time, as master 16.67 - - ns S16 TCLK_HIGH SSIClk high time, as master 8.33 - - ns S17 TCLK_LOW SSIClk low time, as master 8.33 - - ns c S18 TCLKR SSIClk rise time 1.25 - - ns S19 TCLKF SSIClk fall time c 1.25 - - ns S20 TTXDMOV Master Mode: Master SSInXDATn Data Output (to slave) Valid Time from edge of SSIClk - - 4.04 ns S21 TTXDMOH Master Mode: Master SSInXDATn Data Output (to slave) Hold Time after next SSIClk 0.60 - - ns S22 TRXDMS Master Mode: Master SSInXDATn Data In (from slave) setup time 5.78 - - ns S23 TRXDMH Master Mode: Master SSInXDATn Data In (from slave) hold time 0 - - ns a. Parameters S15 through S23 correspond to parameters S1 through S9 in Figure 27-30 and Figure 27-31. b. In master mode, the system clock must be at least twice as fast as the SSIClk. c. Note that the delays shown are using 12-mA drive strength. June 18, 2014 1869 Texas Instruments-Production Data Electrical Characteristics 27.18 Inter-Integrated Circuit (I2C) Interface Table 27-48. I2C Characteristics Parameter No. Parameter Parameter Name Min Nom Max Unit a TSCH Start condition hold time 36 - - system clocks a TLP Clock Low period 36 - - system clocks b I3 TSRT I2CSCL/I2CSDA rise time (VIL =0.5 V to V IH =2.4 V) - - (see note b) ns I4 TDH Data hold time (slave) - 2 - system clocks Data hold time (master) - 7 - system clocks c TSFT I2CSCL/I2CSDA fall time (VIH =2.4 V to V IL =0.5 V) - 9 10 ns a THT Clock High time 24 - - system clocks TDS I1 I2 I5 I6 I7 Data setup time 18 - - system clocks a TSCSR Start condition setup time (for repeated start condition only) 36 - - system clocks I9 a TSCS Stop condition setup time 24 - - system clocks Data Valid (slave) - 2 - system clocks I10 TDV Data Valid (master) - (6 * (1 + TPR)) + 1 - system clocks I8 a. Values depend on the value programmed into the TPR bit in the I2C Master Timer Period (I2CMTPR) register; a TPR programmed for the maximum I2CSCL frequency (TPR=0x2) results in a minimum output timing as shown in the table above. The I 2C interface is designed to scale the actual data transition time to move it to the middle of the I2CSCL Low period. The actual position is affected by the value programmed into the TPR; however, the numbers given in the above values are minimum values. b. Because I2CSCL and I2CSDA operate as open-drain-type signals, which the controller can only actively drive low, the time I2CSCL or I2CSDA takes to reach a high level depends on external signal capacitance and pull-up resistor values. c. Specified at a nominal 50 pF load. Figure 27-33. I2C Timing I2 I10 I6 I5 I2CSCL I1 I4 I7 I8 I3 I9 I2CSDA 1870 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.19 Ethernet Controller 27.19.1 DC Characteristics The parameters listed in Table 27-49 on page 1871, with the exception of RBIAS, apply to transmit pins of the Ethernet PHY, which are generally the EN0TXOP and EN0TX0N signals during standard operation but can also be the EN0RXIN EN0RXIP signals if Auto-MDIX is enabled. Table 27-49. Ethernet PHY DC Characteristics 27.19.2 Parameter Parameter Name Min Nom Max Unit RBIAS Value of the pull-down resistor on the RBIAS pin 4.82 4.87 4.92 kΩ VTPTD_100 100M transmit voltage 0.95 1 1.05 V VTPTDSYM 100M transmit voltage symmetry -2 - 2 % VOVRSHT Output overshoot - - 5 % VTPTD_10 10M transmit voltage 2.2 2.5 2.8 V VTH1 10Base-T Receive threshold - 200 - mV Clock Characteristics a Table 27-50. MOSC 25-MHz Crystal Specification Parameter No. Parameter N1 FMOSC25 - Parameter Name Min Nom Max Unit Frequency - 25 - MHz FTOL Frequency tolerance at operational temperature 0 - ±50 ppm TSTA Frequency stability at 1-year aging - - ±5 ppm Min Nom Max Unit a. Refer to Table 27-23 on page 1838 for additional MOSC requirements. Figure 27-34. MOSC Crystal Characteristics for Ethernet N1 OSC0 a Table 27-51. MOSC Single-Ended 25-MHz Oscillator Specification Parameter No. Parameter Parameter Name N4 FOSC Frequency - 25 - MHz - FTOL Frequency tolerance at operational temperature 0 - ±50 ppm - TSTA Frequency stability at 1-year aging - - ±50 ppm N5 TRF Frequency rise and fall time - - 1 ns June 18, 2014 1871 Texas Instruments-Production Data Electrical Characteristics a Table 27-51. MOSC Single-Ended 25-MHz Oscillator Specification (continued) Parameter No. Parameter - TJ - DC Parameter Name Min Nom Max Unit - 50 - ps - - 1 ns 40 - 60 % Jitter (cycle-to-cycle) Jitter (over 10 ms) Duty cycle Figure 27-35. Single-Ended MOSC Characteristics for Ethernet N4 N5 N5 OSC0 27.19.3 AC Characteristics Table 27-52. Ethernet Controller Enable and Software Reset Timing Parameter No. Parameter N16 TEN N17 TSWRST Parameter Name Min Nom Max Unit Time from the System Control enable of the ab PHY to energy on the PMD output pin 45 - - µs Time from software reset of the PHY to energy on the PMD output pin 110 - - ns a. The PHY is enabled through System Control by setting the P0 bit in the PCEPHY register and the R0 bit in the RCGCPHY register. b. This minimum timing assumes the PHYHOLD bit in the EMACPC register is not set. Figure 27-36. Reset Timing CLK PHY Enable N16 PHY SW Reset N17 PMD Output Pair Table 27-53. 100Base-TX Transmit Timing (tR/F and Jitter) Parameter No. N38 Parameter TRF TRF_MM Parameter Name 100 Mb/s PMD output pair tR and a tF bc 100 Mb/s tR and tF symmetry 1872 Min Nom Max Unit 3 - 4 5 ns - 500 ps June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-53. 100Base-TX Transmit Timing (tR/F and Jitter) (continued) Parameter No. Parameter N39 TRF_JTTR Parameter Name Min Nom Max Unit - - 1.4 ns 100 Mb/s PMD Output Pair Transmit Jitter a. Rise and fall times taken at 10% and 90% of the +1 or -1 amplitude. b. Normal mismatch is the difference between the maximum and minimum of all rise and fall times c. Choice of Ethernet transformer magnetics can affect this parameter. Figure 27-37. 100 Base-TX Transmit Timing 90% 90% 10% PMD Output Pair 10% 90% +1 rise 90% +1 fall N38 N38 10% -1 fall -1 rise N38 N39 10% N38 PMD Output Pair Eye Pattern N39 Table 27-54. 10Base-T Normal Link Pulse Timing Parameter No. Parameter Parameter Name Min Nom Max Unit N69 TLP_PER Link pulse period - 76 - ms N70 TLP_WID Link pulse width - 100 - µs Figure 27-38. 10Base-TX Normal Link Pulse Timing N69 N70 Normal Link Pulse(s) June 18, 2014 1873 Texas Instruments-Production Data Electrical Characteristics Table 27-55. Auto-Negotiation Fast Link Pulse (FLP) Timing Parameter No. Parameter Parameter Name Min Nom Max Unit N72 TCLKP Clock pulse to clock pulse period - 125 - µs N73 TCLKDP Clock Pulse to Data Pulse Period - 62 - µs N74 TPUL Clock, Data Pulse Width - 110 - ns N75 TBRSTP FLP Burst to FLP Burst Period - 16 - ms N76 TBRSTW Burst Width - 2 - ms Figure 27-39. Auto-Negotiation Fast Link Pulse Timing N76 N72 N73 N74 N74 Fast Link Pulse(s) Clock Pulse Data Pulse Clock Pulse N75 N76 FLP Burst FLP Burst Table 27-56. 100Base-TX Signal Detect Timing Parameter No. Parameter Parameter Name Min Nom Max Unit N79 TON SD Internal Turn-on Time - - 100 µs N80 TOFF Internal Turn-off Time - - 200 µs Figure 27-40. 100Base-TX Signal Detect Timing PMD Input Pair N79 N80 Signal Detect (Internal) 1874 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.20 Universal Serial Bus (USB) Controller The Tiva™ C Series USB controller electrical specifications are compliant with the Universal Serial Bus Specification Rev. 2.0 (full-speed and low-speed support) and the On-The-Go Supplement to the USB 2.0 Specification Rev. 1.0. Some components of the USB system are integrated within the TM4C1294NCPDT microcontroller and specific to the Tiva™ C Series microcontroller design. Note: GPIO pin, PB1, which can be configured as the USB0VBUS signal, is the only pin which is 5-V tolerant on the device. Table 27-57. ULPI Interface Timing Parameter No. Parameter Parameter Name Min Nom Max Unit Timings with respect to external clock source input to USB0CLK U1 TSUC Setup time (control in) USB0DIR, USB0NXT 4.8 - - ns U2 TSUD Setup Time (data in) USB0Dn 3.5 - - ns U3 THTC Hold Time (control in) USB0DIR, USB0NXT 0 - - ns U4 THTD Hold Time (data in) USB0Dn 0 - - ns U5 TODC Output Delay (control out) USB0STP 3.7 - 9.5 ns U6 TODD Output Delay (data out) USB0Dn 3.7 - 9.5 ns Timings with USB0CLK as clock output U1 TSUC Setup time (control in) USB0DIR, USB0NXT 6.0 - - ns U2 TSUD Setup Time (data in) USB0Dn 4.6 - - ns U3 THTC Hold Time (control in) USB0DIR, USB0NXT 0 - - ns U4 THTD Hold Time (data in) USB0Dn 0 - - ns U5 TODC Output Delay (control out) USB0STP 4.0 - 10.6 ns U6 TODD Output Delay (data out) USB0Dn 4.0 - 10.6 ns June 18, 2014 1875 Texas Instruments-Production Data Electrical Characteristics Figure 27-41. ULPI Interface Timing Diagram USB0CLK U5 USB0STP U6 USB0Dn Write U1 U3 U2 U4 USB0DIR/ USB0NXT USB0Dn Read 1876 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.21 Analog Comparator ab Table 27-58. Analog Comparator Characteristics Parameter Parameter Name c VINP,VINN VCM VOS IINP,IINN CMRR Min Nom Max Unit Input voltage range GNDA - VDDA V Input common mode voltage range GNDA - VDDA V d Input offset voltage - ±10 ±50 mV Input leakage current over full voltage range - - 2.0 µA Common mode rejection ratio - 50 - dB e TRT Response time - - 1.0 µs TMC Comparator mode change to Output Valid - - 10 µs a. Best design practices suggest that static or quiet digital I/O signals be configured adjacent to sensitive analog inputs to reduce capacitive coupling and cross talk. b. To achieve best analog results, the source resistance driving the analog inputs, VINP and VINN, should be kept low. c. The external voltage inputs to the Analog Comparator are designed to be highly sensitive and can be affected by external noise on the board. For this reason, VINP and VINN must be set to different voltage levels during idle states to ensure the analog comparator triggers are not enabled. If an internal voltage reference is used, it should be set to a mid-supply level. When operating in Sleep/Deep-Sleep modes, the Analog Comparator module should be disabled or the external voltage inputs set to different levels (greater than the input offset voltage) to achieve minimum current draw. d. Measured at VREF=100 mV. e. Measured at external VREF=100 mV, input signal switching from 75 mV to 125 mV. Table 27-59. Analog Comparator Voltage Reference Characteristics Parameter Parameter Name Min Nom Max Unit RHR Resolution in high range - VDDA/29.4 - V RLR Resolution in low range - VDDA/22.12 - V AHR Absolute accuracy high range - - ±RHR/2 V ALR Absolute accuracy low range - - ±RLR/2 V Table 27-60. Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 0 VREF Value VIREF Min Ideal VIREF VIREF Max Unit 0x0 0.731 0.786 0.841 V 0x1 0.843 0.898 0.953 V 0x2 0.955 1.010 1.065 V 0x3 1.067 1.122 1.178 V 0x4 1.180 1.235 1.290 V 0x5 1.292 1.347 1.402 V 0x6 1.404 1.459 1.514 V 0x7 1.516 1.571 1.627 V 0x8 1.629 1.684 1.739 V 0x9 1.741 1.796 1.851 V 0xA 1.853 1.908 1.963 V 0xB 1.965 2.020 2.076 V 0xC 2.078 2.133 2.188 V June 18, 2014 1877 Texas Instruments-Production Data Electrical Characteristics Table 27-60. Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 0 (continued) VREF Value VIREF Min Ideal VIREF VIREF Max Unit 0xD 2.190 2.245 2.300 V 0xE 2.302 2.357 2.412 V 0xF 2.414 2.469 2.525 V Table 27-61. Analog Comparator Voltage Reference Characteristics, VDDA = 3.3V, EN= 1, and RNG = 1 VREF Value VIREF Min Ideal VIREF VIREF Max Unit 0x0 0.000 0.000 0.074 V 0x1 0.076 0.149 0.223 V 0x2 0.225 0.298 0.372 V 0x3 0.374 0.448 0.521 V 0x4 0.523 0.597 0.670 V 0x5 0.672 0.746 0.820 V 0x6 0.822 0.895 0.969 V 0x7 0.971 1.044 1.118 V 0x8 1.120 1.193 1.267 V 0x9 1.269 1.343 1.416 V 0xA 1.418 1.492 1.565 V 0xB 1.567 1.641 1.715 V 0xC 1.717 1.790 1.864 V 0xD 1.866 1.939 2.013 V 0xE 2.015 2.089 2.162 V 0xF 2.164 2.238 2.311 V 1878 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller 27.22 Pulse-Width Modulator (PWM) Table 27-62. PWM Timing Characteristics Parameter TFLTW Parameter Name Minimum Fault Pulse Width a TFLTMAX MnFAULTn Assertion to PWM Inactive TFLTMIN MnFAULTn De-Assertion to PWM Active b Min Nom Max Unit 2 - - PWM clock periods - - 24 + (1 PWM clock) ns 5 - - ns a. This parameter value can vary depending on the PWM clock frequency which is controlled by the System Clock and a programmable divider field in the PWMCC register. b. The latch and minimum fault period functions that can be enabled in the PWMnCTL register can change the timing of this parameter. June 18, 2014 1879 Texas Instruments-Production Data Electrical Characteristics 27.23 Current Consumption Table 27-64 on page 1884 shows the amount of current consumption that specific peripherals contribute to the Run mode current consumption numbers shown in Table 27-63 on page 1880. If these peripherals are not powered, then the peripheral current consumption values can be subtracted from the Run mode numbers displayed in Table 27-63 on page 1880. ab Table 27-63. Current Consumption System Clock Parameter Nom Max 85°C 105°C c Unit 96.4 105.3 107.2 108.7 129.9 140.0 mA 67.4 76.6 78.6 79.9 100.3 112.5 mA PIOSC 11.9 24.4 25.5 26.7 45.0 56.4 mA PIOSC 5.75 10.9 12.1 13.3 31.3 42.6 mA 120 MHz MOSC with PLL 69.9 77.8 79.6 80.8 98.8 108.4 mA VDDA = 3.3 V 60 MHz MOSC with PLL 40.9 49.2 50.9 52.1 69.2 80.8 mA Peripherals = All ON including MAC but not PHY 16 MHz PIOSC 11.3 23.6 25.0 26.2 43.1 54.3 mA Parameter Name Conditions Frequency Clock Source 120 MHz MOSC with PLL VDDA = 3.3 V 60 MHz Peripherals = All ON including MAC and PHY MOSC with PLL 16 MHz 1 MHz VDD = 3.3 V VDD = 3.3 V -40°C 25°C 85°C c 105°C 1 MHz PIOSC 5.10 10.1 11.5 12.7 29.3 40.5 mA 120 MHz MOSC with PLL 68.1 76.0 77.6 78.6 96.6 106.0 mA VDDA = 3.3 V 60 MHz 40.0 48.2 49.8 50.8 67.9 79.2 mA Peripherals = All ON except MAC/PHY MOSC with PLL 16 MHz PIOSC 11.1 23.3 24.6 25.6 42.5 53.3 mA Run mode (Flash loop) VDD = 3.3 V 1 MHz PIOSC 5.07 10.1 11.3 12.3 29.0 39.8 mA 120 MHz MOSC with PLL 35.2 39.1 40.4 41.5 55.8 65.3 mA 60 MHz MOSC with PLL 23.2 29.4 30.7 31.7 45.8 55.5 mA 16 MHz PIOSC 7.38 17.9 19.0 20.0 34.5 44.1 mA 1 MHz PIOSC 4.12 9.13 10.3 11.4 25.7 35.5 mA 120 MHz MOSC with PLL 93.8 103.6 111.6 113.2 133.4 144.6 mA VDDA = 3.3 V 60 MHz MOSC with PLL 66.9 76.7 78.7 80.0 100.0 111.9 mA Peripherals = All ON including MAC and PHY 16 MHz PIOSC 12.6 19.0 20.1 21.3 39.1 50.3 mA 1 MHz PIOSC 5.73 10.6 11.7 12.8 30.9 42.2 mA 120 MHz MOSC with PLL 67.2 76.1 84.0 85.4 102.3 113.0 mA IDD_RUN VDD = 3.3 V VDDA = 3.3 V Peripherals = All OFF VDD = 3.3 V Run mode (SRAM VDD = 3.3 V loop) VDDA = 3.3 V 60 MHz MOSC with PLL 40.3 49.2 50.9 52.2 68.9 80.2 mA Peripherals = All ON including MAC but not PHY 16 MHz PIOSC 11.9 18.2 19.6 20.8 37.2 48.2 mA 1 MHz PIOSC 5.08 9.79 11.2 12.3 28.9 40.1 mA VDD = 3.3 V 120 MHz MOSC with PLL 65.4 74.3 82.0 83.2 100.1 110.6 mA VDDA = 3.3 V 1880 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-63. Current Consumption (continued) System Clock Parameter Parameter Name Conditions Clock Source 60 MHz MOSC with PLL 16 MHz 1 MHz -40°C 25°C 85°C 105°C c 85°C 105°C Unit 48.2 49.8 50.9 67.6 78.6 mA PIOSC 11.7 17.9 19.2 20.2 36.6 47.2 mA PIOSC 5.05 9.75 11.0 11.9 28.6 39.4 mA 120 MHz MOSC with PLL 35.4 43.3 44.7 45.8 59.8 69.0 mA 60 MHz MOSC with PLL 23.4 29.4 30.7 31.7 45.5 54.9 mA Peripherals = All OFF 16 MHz PIOSC 7.08 12.4 13.6 14.6 28.7 38.0 mA 1 MHz PIOSC 4.60 8.78 10.0 11.0 25.3 34.9 mA VDD = 3.3 V 120 MHz MOSC with PLL 82.8 94.8 96.8 98.1 117.9 129.1 mA 60 MHz MOSC with PLL 60.8 69.2 71.2 72.3 91.8 102.9 mA 16 MHz PIOSC d 11.2 16.8 18.1 19.1 35.4 45.9 mA d VDD = 3.3 V VDDA = 3.3 V VDDA = 3.3 V Peripherals = All ON including MAC and PHY LDO = 1.2 V 1 MHz PIOSC 5.10 10.3 11.5 12.6 28.9 39.6 mA VDD = 3.3 V 120 MHz MOSC with PLL 56.2 67.4 69.1 70.3 87.1 97.8 mA VDDA = 3.3 V Peripherals = All ON including MAC but not PHY 60 MHz MOSC with PLL 34.4 41.9 43.4 44.5 60.7 71.6 mA 16 MHz PIOSC d 10.6 16.2 17.5 18.5 34.5 45.1 mA LDO = 1.2 V 1 MHz PIOSC d 4.47 9.60 10.9 12.0 28.0 38.7 mA 120 MHz MOSC with PLL 54.4 65.6 67.1 68.1 84.9 95.4 mA 60 MHz MOSC with PLL 33.5 40.9 42.3 43.2 59.4 70.0 mA 16 MHz PIOSC d 10.4 15.9 17.1 17.9 33.9 44.1 mA 1 MHz d PIOSC 4.44 9.56 10.7 11.6 27.7 38.0 mA 120 MHz MOSC with PLL 22.0 28.6 29.8 30.7 44.1 53.1 mA 60 MHz MOSC with PLL 16.3 22.0 23.2 24.1 37.5 46.6 mA 16 MHz PIOSC d 5.37 10.4 11.5 12.4 26.1 35.1 mA 1 MHz PIOSC d 4.37 8.60 9.71 10.6 24.6 33.9 mA 120 MHz MOSC with PLL 86.5 89.0 91.2 92.5 112.1 123.5 mA 60 MHz MOSC with PLL 61.6 63.4 65.6 66.7 86.0 97.2 mA 16 MHz PIOSC d 10.4 11.1 12.4 13.5 29.8 40.4 mA 1 MHz d PIOSC 4.45 4.49 5.83 6.98 23.4 34.2 mA 120 MHz MOSC with PLL 59.9 61.7 63.4 64.7 81.3 92.1 mA 60 MHz MOSC with PLL 35.1 36.1 37.8 38.9 54.9 66.0 mA VDD = 3.3 V VDDA = 3.3 V Peripherals = All ON except MAC/PHY IDD_SLEEP Frequency Max c 39.4 Peripherals =All ON except MAC/PHY Sleep mode (FLASHPM = 0x0) Nom LDO = 1.2 V VDD = 3.3 V VDDA = 3.3 V Peripherals = All OFF LDO = 1.2 V VDD = 3.3 V VDDA = 3.3 V Peripherals = All ON including MAC and PHY Sleep mode (FLASHPM = 0x2) LDO = 1.2 V VDD = 3.3 V VDDA = 3.3 V June 18, 2014 1881 Texas Instruments-Production Data Electrical Characteristics Table 27-63. Current Consumption (continued) System Clock Parameter Parameter Name Conditions Peripherals = All ON including MAC but not PHY Nom Frequency Clock Source 16 MHz PIOSC 1 MHz -40°C 25°C Max c 85°C 105°C c 85°C 105°C Unit d 9.75 10.4 11.8 12.9 28.9 39.6 mA PIOSC d 3.82 3.82 5.25 6.38 22.5 33.4 mA 120 MHz MOSC with PLL 58.1 59.9 61.4 62.5 79.1 89.7 mA 60 MHz MOSC with PLL 34.2 35.1 36.7 37.6 53.6 64.4 mA 16 MHz PIOSC d 9.50 10.1 11.4 12.3 28.3 38.6 mA 1 MHz PIOSC d 3.79 3.78 5.06 5.96 22.2 32.7 mA 120 MHz MOSC with PLL 22.0 22.8 24.1 25.1 38.2 47.4 mA 60 MHz MOSC with PLL 15.7 16.2 17.5 18.5 31.7 40.9 mA 16 MHz PIOSC d 4.50 4.60 5.80 6.80 20.5 29.8 mA d PIOSC 3.00 2.80 4.10 5.20 19.1 28.7 mA LDO = 1.2 V VDD = 3.3 V VDDA = 3.3 V Peripherals = All ON except MAC/PHY LDO = 1.2 V VDD = 3.3 V VDDA = 3.3 V Peripherals = All OFF LDO = 1.2 V 1 MHz VDD = 3.3 V 16 MHz PIOSC 9.74 9.78 10.8 11.6 24.1 32.1 mA VDDA = 3.3 V 30 kHz LFIOSC 2.60 2.83 3.83 4.60 17.1 25.3 mA VDD = 3.3 V 16 MHz PIOSC 4.53 4.05 4.88 5.53 15.9 22.7 mA VDDA = 3.3 V 30 kHz LFIOSC 0.614 0.762 1.69 2.46 13.3 20.7 mA Peripherals = All ON LDO = 1.2 V Peripherals = All OFF e IDD_DEEPSLEEP Deep-Sleep mode LDO = 1.2 V (FLASHPM = 0x2) VDD = 3.3 V 16 MHz PIOSC 5.21 7.33 7.97 8.48 15.3 20.1 mA VDDA = 3.3 V 30 kHz LFIOSC 2.02 2.16 2.79 3.29 10.0 14.9 mA VDD = 3.3 V 16 MHz PIOSC 1.08 3.10 3.61 4.01 9.50 13.4 mA VDDA = 3.3 V 30 kHz LFIOSC 0.367 0.454 0.954 1.36 6.86 10.8 mA 120 MHz MOSC with PLL 2.61 2.66 2.68 2.66 3.03 3.35 mA 60 MHz MOSC with PLL 2.61 2.66 2.68 2.66 3.04 3.10 mA 16 MHz PIOSC 2.45 2.49 2.50 2.48 2.85 2.95 mA 2.45 2.48 2.50 2.48 2.84 Peripherals = All ON f LDO = 0.9 V Peripherals = All OFF f LDO = 0.9 V VDD = 3.3 V VDDA = 3.3 V Peripherals = All ON IDDA_RUN, IDDA_SLEEP All Run modes All Sleep modes VDD = 3.3 V VDDA = 3.3 V Peripherals = All OFF 1 MHz PIOSC 2.90 mA 120 MHz MOSC with PLL 0.227 0.229 0.270 0.250 0.559 0.650 mA 60 MHz MOSC with PLL 0.229 0.232 0.267 0.250 0.579 0.600 mA 16 MHz PIOSC 0.228 0.229 0.265 0.251 0.545 0.575 mA 1 MHz PIOSC 0.227 0.227 0.267 0.247 0.549 0.555 mA 1882 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller Table 27-63. Current Consumption (continued) System Clock Parameter Parameter Name Conditions Frequency Clock Source Nom -40°C 25°C Max c 85°C 105°C c 85°C 105°C Unit VDD = 3.3 V 16 MHz PIOSC 2.45 2.48 2.50 2.48 2.84 2.90 mA VDDA = 3.3 V 30 kHz LFIOSC 2.45 2.48 2.50 2.48 2.85 2.90 mA Peripherals = All ON LDO = 1.2 V VDD = 3.3 V 16 MHz PIOSC 0.226 0.227 0.265 0.249 0.558 0.635 mA VDDA = 3.3 V 30 kHz LFIOSC 0.228 0.227 0.272 0.247 0.558 0.600 mA 16 MHz PIOSC 2.14 2.42 2.44 2.42 2.78 2.88 mA 30 kHz LFIOSC 2.44 2.42 2.44 2.42 2.86 2.88 mA VDD = 3.3 V 16 MHz PIOSC 0.216 0.166 0.209 0.193 0.563 0.580 mA VDDA = 3.3 V 30 kHz LFIOSC 0.223 0.167 0.209 0.189 0.508 0.580 mA - - 1.04 1.20 1.44 1.69 1.62 2.14 µA - - 1.12 1.29 1.54 1.82 1.75 2.33 µA - - 6.78 7.99 17.0 22.1 31.0 46.2 µA - - 5.42 6.39 15.4 17.8 28.9 32.0 µA Peripherals = All OFF LDO = 1.2 V IDDA_DEEPSLEEP Deep-Sleep mode (FLASHPM = 0x2) VDD = 3.3 V VDDA = 3.3 V Peripherals = All ON f LDO = 0.9 V Peripherals = All OFF f LDO = 0.9 V IHIB_NORTC Hibernate mode (external wake, RTC disabled) VBAT = 3.0 V VDD = 0 V VDDA = 0 V System Clock = OFF Hibernate Module = 32.768 kHz IHIB_RTC Hibernate mode (RTC enabled) VBAT = 3.0 V VDD = 0 V VDDA = 0 V System Clock = OFF Hibernate Module = 32.768 kHz Hibernate mode VBAT = 3.0 V (VDD3ON mode, V = 3.3 V DD Tamper enabled) VDDA = 3.3 V System Clock = OFF IHIB_VDD3ON Hibernate Module = 32.768 kHz Hibernate mode VBAT = 3.0 V (VDD3ON mode, V = 3.3 V DD Tamper disabled) VDDA = 3.3 V System Clock = OFF Hibernate Module = 32.768 kHz a. Total current in RUN, SLEEP and DEEPSLEEP modes is the sum of IDDand IDDA. b. For Peripherals = All OFF, the clocks to all peripherals are turned off and the peripherals are powered down, if capable (see the section called “Peripheral Power Control” on page 243). c. Applicable to extended temperature devices only. June 18, 2014 1883 Texas Instruments-Production Data Electrical Characteristics d. Note that if the MOSC is the source of the Run-mode system clock and is powered down in Sleep mode, wake time is increased by TMOSC_SETTLE. e. To achieve the lowest possible Deep-Sleep current, one or more wait states must be configured in the MEMTIM0 register. If there are no wait states applied in Run mode, then lowest possible Deep-Sleep current is not achieved. f. See the section called “LDO Power Control” on page 244 for information on lowering the LDO voltage to 0.9 V. Table 27-64. Peripheral Current Consumption Parameter Parameter Name IDDUSB USB (including USB PHY) run mode current IDDEMACPHY Ethernet MAC and PHY run mode current Conditions VDD = 3.3 V VDDA = 3.3 V VDD = 3.3 V VDDA = 3.3 V System Clock Nom Units 120 MHz (MOSC with PLL) 4.0 mA 120 MHz (MOSC with PLL) 30 mA 1884 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller A Package Information A.1 Orderable Devices The figure below defines the full set of orderable part numbers for the TM4C129x Series. See the Package Option Addendum for the complete list of valid orderable part numbers for the TM4C1294NCPDT microcontroller. Figure A-1. Key to Part Numbers T M4 C 1 SSS M Y PPP T XX Z R Shipping Medium R = Tape-and-reel Omitted = Default shipping (tray or tube) Prefix T = Qualified Device X = Experimental Device Revision Core M4 = ARM® Cortex™-M4 Special Codes Optional Tiva Series C = Connected MCUs Temperature I = –40°C to +85°C T = –40°C to +105°C Package PDT = 128-pin TQFP ZAD = 212-ball BGA Data Memory C = 256 KB Family Part Number SSS = Series identifier Program Memory K = 512 KB N = 1024 KB A.2 Device Nomenclature To designate the stages in the product development cycle, TI assigns prefixes to the part numbers of all microcontroller (MCU) devices. Each Tiva™ C Series family member has one of two prefixes: XM4C or TM4C. These prefixes represent evolutionary stages of product development from engineering prototypes (XM4C) through fully qualified production devices (TM4C). Device development evolutionary flow: ■ XM4C — Experimental device that is not necessarily representative of the final device's electrical specifications and may not use production assembly flow. ■ TM4C — Production version of the silicon die that is fully qualified. XM4C devices are shipped against the following disclaimer: "Developmental product is intended for internal evaluation purposes." TM4C devices have been characterized fully, and the quality and reliability of the device have been demonstrated fully. TI's standard warranty applies. Predictions show that prototype devices (XM4C) have a greater failure rate than the standard production devices. Texas Instruments recommends that these devices not be used in any production system because their expected end-use failure rate still is undefined. Only qualified production devices are to be used. A.3 Device Markings The figure below shows an example of the Tiva™ microcontroller package symbolization. June 18, 2014 1885 Texas Instruments-Production Data Package Information $$ TM4C129X NCZADI3 YMLLLLS G1 This identifying number contains the following information: ■ Lines 1 and 5: Internal tracking numbers ■ Lines 2 and 3: Part number For example, TM4C129X on the second line followed by NCZADI3 on the third line indicates orderable part number TM4C129XNCZADI3. Note that the first letter in the part number indicates the product status. A T indicates the part is fully qualified and released to production; an X indicates the part is experimental (pre-production) and requires a waiver. The silicon revision number is the last number in the part number, in this example, 3. The DID0 register identifies the version of the microcontroller, as shown in the table below. Combined, the MAJOR and MINOR bit fields indicate the die revision and part revision numbers. MAJOR Bitfield Value MINOR Bitfield Value Die Revision Part Revision 0x0 0x0 A0 1 0x0 0x1 A1 2 0x0 0x2 A2 3 ■ Line 4: Date code The first two characters on the fourth line indicate the date code, followed by internal tracking numbers. The two-digit date code YM indicates the last digit of the year, then the month. For example, a 34 for the first two digits of the fourth line indicates a date code of April 2013. 1886 June 18, 2014 Texas Instruments-Production Data Tiva™ TM4C1294NCPDT Microcontroller A.4 Packaging Diagram Figure A-2. TM4C1294NCPDT 128-Pin TQFP Package Diagram MECHANICAL DATA MPQF013 – NOVEMBER 1995 PDT (S-PQFP-G128) PLASTIC QUAD FLATPACK 0,23 0,13 0,40 96 0,05 M 65 97 64 128 33 1 0,13 NOM 32 12,40 TYP Gage Plane 14,05 SQ 13,95 16,10 SQ 15,90 0,25 0,05 MIN 0°– 5° 0,75 0,45 1,05 0,95 Seating Plane 0,08 1,20 MAX 4087726/A 11/95 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. June 18, 2014 1887 Texas Instruments-Production Data POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) TM4C1294NCPDTI3 ACTIVE TQFP PDT 128 90 RoHS & Green NIPDAU Level-3-260C-168 HR -40 to 85 TM4C129 4NCPDTI3 TM4C1294NCPDTI3R ACTIVE TQFP PDT 128 1000 RoHS & Green NIPDAU Level-3-260C-168 HR -40 to 85 TM4C129 4NCPDTI3 TM4C1294NCPDTT3 ACTIVE TQFP PDT 128 90 RoHS & Green NIPDAU Level-3-260C-168 HR -40 to 105 TM4C129 4NCPDTT3 TM4C1294NCPDTT3R ACTIVE TQFP PDT 128 1000 RoHS & Green NIPDAU Level-3-260C-168 HR -40 to 105 TM4C129 4NCPDTT3 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of