MC68334GCFC16

Freescale Semiconductor Order this document by MC68334TS/D REV. 1 MC68334 Technical Summary 32-Bit Modular Microcontroller 1 Introduction The MC68334, a highly-integrated 32-bit microcontroller, combines high-performance data manipulation capabilities with powerful peripheral subsystems. The MCU is built up from standard modules that interface through a common intermodule bus (IMB). Standardization facilitates rapid development of devices tailored for specific applications. The MCU incorporates a 32-bit CPU (CPU32), a system integration module (SIM), an 8/10-bit analogto-digital converter (ADC), a time processor unit (TPU) and a 1-Kbyte static RAM module with TPU emulation capability (TPURAM). The MCU can either synthesize an internal clock signal from an external reference or use an external clock input directly. Operation with a 32.768-kHz reference frequency is standard. The maximum system clock speed is 20.97 MHz. System hardware and software allow changes in clock rate during operation. Because MCU operation is fully static, register and memory contents are not affected by clock rate changes. High-density complementary metal-oxide semiconductor (HCMOS) architecture makes the basic power consumption of the MCU low. Power consumption can be minimized by stopping the system clock. The CPU32 instruction set includes a low-power stop (LPSTOP) command that efficiently implements this capability. This document contains information about a new product. Specifications and information herein are subject to change without notice. Table 1 Ordering Information Package Type 132-Pin PQFP TPU Type Motion Control Temperature –40 to +85 °C –40 to +105 °C –40 to +125 °C SP Prefix 2-Piece Tray Order Quantity No Affix 36-Piece Tray © Freescale Semiconductor, Inc., 2004. All rights reserved. Frequency 16 MHz 20 MHz 16 MHz 20 MHz 16 MHz 20 MHz B1 Suffix 180 (5 Trays) Order Number MC68334GCFC16 MC68334GCFC20 MC68334GVFC16 MC68334GVFC20 MC68334GMFC16 MC68334GMFC20 TABLE OF CONTENTS Section 1 Page 8 Introduction 1 Features ......................................................................................................................................3 Block Diagram .............................................................................................................................3 Pin Assignments ..........................................................................................................................5 Address Map ...............................................................................................................................6 Intermodule Bus ..........................................................................................................................6 Signal Descriptions 7 Pin Characteristics ......................................................................................................................7 MCU Power Connections ............................................................................................................8 MCU Driver Types .......................................................................................................................8 Signal Characteristics ..................................................................................................................9 Signal Function ..........................................................................................................................10 System Integration Module 11 Overview ...................................................................................................................................11 System Configuration and Protection Block ..............................................................................13 System Clock ............................................................................................................................19 External Bus Interface ...............................................................................................................24 Chip Selects ..............................................................................................................................28 General-Purpose Input/Output ..................................................................................................35 Resets .......................................................................................................................................37 Interrupts ...................................................................................................................................40 Factory Test Block .....................................................................................................................42 Central Processor Unit 43 Overview ...................................................................................................................................43 Programming Model ..................................................................................................................43 Status Register ..........................................................................................................................44 Data Types ................................................................................................................................45 Addressing Modes .....................................................................................................................45 Instruction Set Summary ...........................................................................................................46 Background Debugging Mode ...................................................................................................49 Time Processor Unit 51 Overview ...................................................................................................................................51 Programmer's Model .................................................................................................................51 TPU Components ......................................................................................................................52 TPU Operation ..........................................................................................................................54 Emulation Support .....................................................................................................................55 Time Functions ..........................................................................................................................55 TPU Registers ...........................................................................................................................57 Analog-to-Digital Converter Module 63 Analog Subsystem ....................................................................................................................63 Digital Control Subsystem .........................................................................................................63 ADC Address Map .....................................................................................................................64 ADC Registers ...........................................................................................................................66 Standby RAM with TPU Emulation 72 Overview ...................................................................................................................................72 TPURAM Register Block ...........................................................................................................72 TPURAM Registers ...................................................................................................................72 TPURAM Operation ..................................................................................................................73 Summary of Changes 74 2 MC68334 MC68334TS/D REV. 1 2 3 4 5 6 7 1.1 1.2 1.3 1.4 1.5 2.1 2.2 2.3 2.4 2.5 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.1 4.2 4.3 4.4 4.5 4.6 4.7 5.1 5.2 5.3 5.4 5.5 5.6 5.7 6.1 6.2 6.3 6.4 7.1 7.2 7.3 7.4 1.1 Features • Central Processing Unit (CPU32) — 32-Bit Architecture — Virtual Memory Implementation — Table Lookup and Interpolate Instruction — Improved Exception Handling for Controller Applications — High-Level Language Support — Background Debugging Mode — Fully Static Operation • System Integration Module (SIM) — External Bus Support — Programmable Chip-Select Outputs — System Protection Logic — Watchdog Timer, Clock Monitor, and Bus Monitor — Two 8-Bit Dual Function Input/Output Ports — One 7-Bit Dual Function Output Port — Phase-Locked Loop (PLL) Clock System • 8/10-Bit Analog-to-Digital Converter (ADC) — Seven Analog/Digital Input Pins (Eighth Channel Connected to VSSA) — Eight Result Registers — Eight Conversion Modes — Three Result Alignment Modes — One 7-Bit Digital Input Port • Time Processor Unit (TPU) — Dedicated Microengine Operating Independently of CPU32 — 16 Independent, Programmable Channels and Pins — Any Channel can Perform any Microcoded Time Function — Two Timer Count Registers with Programmable Prescalers — Selectable Channel Priority Levels • 1-Kbyte Standby RAM with TPU Emulation (TPURAM) — External Standby Voltage Supply Input — Can be Used as Standby RAM or TPU Microcode Emulation RAM 1.2 Block Diagram MC68334 MC68334TS/D 3 VSTBY CHIP SELECTS TPUCH[15:0] TPUCH[15:0] T2CLK FC2 FC1 FC0 TPURAM 1 KBYTE TPU ADDR[23:19] T2CLK CONTROL PORT C BR BG BGACK CS[10:0] VRH VRL ADDR[18:0] SIZ1 SIZ0 EBI AS DS RMC AVEC DSACK1 DSACK0 PE7/SIZ1 PE6/SIZ0 PE5/AS PE4/DS PE3/RMC PE2/AVEC PE1/DSACK1 PE0/DSACK0 DATA[15:0] PORT AD CONTROL DATA[15:0] IRQ[7:1] ADC CPU 32 CONTROL PORT F AN6/PADA6 AN5/PADA5 AN4/PADA4 AN3/PADA3 AN2/PADA2 AN1/PADA1 AN0/PADA0 ADDR[23:0] CONTROL PORT E IMB MODCLK BKPT IFETCH IPIPE DSI DSO DSCLK FREEZE CLOCK QUOT TSC CONTROL CONTROL R/W RESET HALT BERR PF7/IRQ7 PF6/IRQ6 PF5/IRQ5 PF4/IRQ4 PF3/IRQ3 PF2/IRQ2 PF1/IRQ1 PF0/MODCLK CLKOUT XTAL EXTAL XFC VDDSYN TEST TSC BKPT/DSCLK IFETCH/DSI IPIPE/DSO CSBOOT ECLK/ADDR23/CS10 PC6/ADDR22/CS9 PC5/ADDR21/CS8 PC4/ADDR20/CS7 PC3/ADDR19/CS6 PC2/FC2/CS5 PC1/FC1/CS4 PC0/FC0/CS3 BGACK/CS2 BG/CS1 BR/CS0 FREEZE/QUOT 334 BLOCK Figure 1 MC68334 Block Diagram 4 MC68334 MC68334TS/D PC7/ADDR23/CS10 PC6/ADDR22/CS9 PC5/ADDR21/CS8 PC4/ADDR20/CS7 PC3/ADDR19/CS6 PC2/FC2/CS5 PC1/FC1/CS4 PC0/FC0/CS3 VSS TPUCH12 TPUCH13 TPUCH14 TPUCH15 T2CLK VSS VDD TPUCH8 TPUCH9 TPUCH10 TPUCH11 VSS VDD TPUCH0 TPUCH1 TPUCH2 TPUCH3 TPUCH4 TPUCH5 TPUCH6 TPUCH7 VSS VDD 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 VSS 1.3 Pin Assignments 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 MC68334 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 VDD BGACK/CS2 BG/CS1 BR/CS0 CSBOOT DATA0 DATA1 DATA2 DATA3 VDD VSS DATA4 DATA5 DATA6 DATA7 VSS DATA8 DATA9 DATA10 DATA11 VDD VSS DATA12 DATA13 DATA14 DATA15 ADDR0 PE0/DSACK0 PE1/DSACK1 PE2/AVEC PE3/RMC PE4/DS VDD EXTAL VDD XFC VDD CLKOUT VSS RESET HALT BERR PF7/IRQ7 PF6/IRQ6 PF5/IRQ5 PF4/IRQ4 PF3/IRQ3 PF2/IRQ2 PF1/IRQ1 PF0/MODCLK R/W PE7/SIZ1 PE6/SIZ0 PE5/AS VSS VRL AN5/PADA5 AN6/PADA6 IPIPE/DSO IFETCH/DSI BKPT/DSCLK TSC FREEZE/QUOT VSS XTAL VDDSYN 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 VDD VSTBY ADDR1 ADDR2 ADDR3 ADDR4 ADDR5 ADDR6 ADDR7 ADDR8 VDD VSS ADDR9 ADDR10 ADDR11 ADDR12 VSS ADDR13 ADDR14 ADDR15 ADDR16 VDD VSS ADDR17 ADDR18 VDD VSS AN0/PADA0 AN1/PADA1 AN2/PADA2 AN3/PADA3 AN4/PADA4 VRH 334 132-PIN QFP Figure 2 MC68334 132-Pin QFP Pin Assignments MC68334 MC68334TS/D 5 1.4 Address Map The following figure is a map of the MCU internal addresses. The RAM array is positioned by the base address registers in the associated RAM control block. Unimplemented blocks are mapped externally. $YFF000 TPURAM ARRAY UPPER 1 KBYTES OF 2-KBYTE BLOCK $YFF700 $YFF740 ADC RESERVED $YFFA00 SIM $YFFA80 $YFFB00 RESERVED TPURAM CONTROL $YFFB40 RESERVED $YFFE00 TPU $YFFFFF Y = M111, where M is the signal state of the module mapping (MM) bit in the SIM configuration register (Y = $7 or Y = $F). 334 ADDRESS MAP Figure 3 MC68334 Address Map 1.5 Intermodule Bus The intermodule bus (IMB) is a standardized bus developed to facilitate both design and operation of modular microcontrollers. It contains circuitry to support exception processing, address space partitioning, multiple interrupt levels, and vectored interrupts. The standardized modules in the MCU communicate with one another and with external components through the IMB. The IMB in the MCU uses 24 address lines and 16 data lines. 6 MC68334 MC68334TS/D 2 Signal Descriptions 2.1 Pin Characteristics The following table shows MCU pins and their characteristics. All inputs detect CMOS logic levels. All inputs can be put in a high-impedance state, but the method of doing this differs depending upon pin function. Refer to the table MCU Driver Types for a description of output drivers. An entry in the discrete I/O column of the MCU Pin Characteristics table indicates that a pin has an alternate I/O function. The port designation is given when it applies. Refer to the MCU Block Diagram for information about port organization. Table 2 MCU Pin Characteristics Pin Mnemonic ADDR23/CS10/ECLK ADDR[22:19]/CS[9:6] ADDR[18:0] AN[6:0] Output Driver A A A — Input Hysteresis N N N Y Discrete I/O — O — I Port Designation — PC[6:3] — PADA[6:0] AS AVEC B B B Y1 Y Y Y N N N I/O I/O — PE5 PE2 — B B — B A B Aw — Y Y Y — — Y — N Y N — — N — — — — — — — — — — — — — — B B B A A — Y Y Y Y — — N N N Y — — I/O I/O I/O — — — PE4 PE1 PE0 — — — A A Bo Y — Y — — N O — — PC[2:0] — — B B Y Y Y N I/O I/O PF[7:1] PF0 VRH4 A Bo B B A — A — Y Y Y Y Y Y Y — N Y N N Y Y Y — — — I/O I/O — — — — — — PE3 PE[7:6] — — — — VRL4 — — — — — BERR2 BG/CS1 BGACK/CS2 BKPT/DSCLK BR/CS0 CLKOUT CSBOOT DATA[15:0]1 DS DSACK1 DSACK0 DSI/IFETCH DSO/IPIPE EXTAL3 FC[2:0]/CS[5:3] FREEZE/QUOT HALT2 IRQ[7:1] MODCLK1 R/W RESET RMC SIZ[1:0] TPUCH[15:0] TSC T2CLK Input Synchronized Y Y Y XFC3 — — — — — XTAL3 — — — — — R/W A Y N — — MC68334 MC68334TS/D 7 Table 2 MCU Pin Characteristics Pin Mnemonic RESET RMC SIZ[1:0] TPUCH[15:0] TSC T2CLK VRH4 Output Driver Bo B B A — A — Input Synchronized Y Y Y Y Y Y — Input Hysteresis Y N N Y Y Y — Discrete I/O — I/O I/O — — — — Port Designation — PE3 PE[7:6] — — — — VRL4 — — — — — XFC3 — — — — — XTAL3 — — — — — NOTES 1. DATA[15:0] are synchronized during reset only. MODCLK and ADC pins are synchronized only when used as input port pins. 2. BERR, HALT only synchronized if late BERR or HALT. 3. EXTAL, XFC, and XTAL are clock reference connections. 4. VRH and VRL are ADC reference voltage points. 2.2 MCU Power Connections Table 3 MCU Power Connections Pin VSTBY VDDSYN VDDA/VSSA VRH/VRL VSSE/VDDE VSSI/VDDI Description Standby RAM Power/Clock Synthesizer Power Clock Synthesizer Power A/D Converter Power A/D Reference Voltage External Periphery Power (Source and Drain) Internal Module Power (Source and Drain) 2.3 MCU Driver Types Table 4 MCU Driver Types 8 Type I/O A O Description Output-only signals that are always driven. No external pull-up required. Aw O Type A output with weak P-channel pull-up during reset. B O Three-state output that includes circuitry to pull up asserted output before high impedance is established, to ensure rapid rise time. An external holding resistor is required to maintain logic level while in the high-impedance state. Pins with this type of driver may only go into high-impedance state under certain conditions. The TSC signal can put all pins with this type of driver in high-impedance state. Bo O Type B output that can be operated in an open-drain mode. MC68334 MC68334TS/D 2.4 Signal Characteristics Table 5 MCU Signal Characteristics MC68334 MC68334TS/D Signal Name ADDR[23:0] AN[6:0] AS AVEC BERR BG BGACK BKPT BR CLKOUT CS[10:0] CSBOOT DATA[15:0] DS DSACK[1:0] DSCLK DSI DSO ECLK EXTAL FC[2:0] FREEZE HALT IFETCH IPIPE IRQ[7:1] MODCLK PADA[6:0] PC[6:0] PE[7:0] PF[7:0] QUOT R/W RESET RMC SIZ[1:0] TPUCH[15:0] TSC T2CLK VRH MCU Module SIM ADC SIM SIM SIM SIM SIM CPU32 SIM SIM SIM SIM SIM SIM SIM CPU32 CPU32 CPU32 SIM SIM SIM SIM SIM CPU32 CPU32 SIM SIM ADC SIM SIM SIM SIM SIM SIM SIM SIM TPU SIM TPU ADC Signal Type Bus Input Output Input Input Output Input Input Input Output Output Output Bus Output Input Input Input Output Output Input Output Output Input/Output Output Output Input Input Input Output Input/Output Input/Output Output Output Input/Output Input/Output Output Input/Output Input Input Input Active State 1/0 — 0 0 0 0 0 0 0 — 0 0 1/0 0 0 Serial Clock Serial Data Serial Data — — 1/0 1 0 0 0 0 — (Port) (Port) (Port) (Port) — 1/0 0 0 1 — 1 — — VRL ADC Input — XFC XTAL SIM SIM Input Output — — 9 2.5 Signal Function Table 6 MCU Signal Function Mnemonic ADDR[23:0] AN[6:0] AS AVEC BERR BG BGACK BKPT BR CLKOUT CS[10:0] CSBOOT DATA[15:0] DS Signal Name Address Bus ADC Analog Input Address Strobe Autovector Bus Error Bus Grant Bus Grant Acknowledge Breakpoint Bus Request System Clockout Chip Selects Boot Chip Select Data Bus Data Strobe DSACK[1:0] Data and Size Acknowledge Development Serial In, Out, Clock E-Clock Crystal Oscillator DSI, DSO, DSCLK ECLK EXTAL, XTAL FC[2:0] FREEZE HALT IFETCH IPIPE IRQ[7:1] MODCLK PADA[6:0] PC[6:0] PE[7:0] PF[7:0] QUOT RESET RMC R/W SIZ[1:0] TPUCH[15:0] TSC T2CLK VRH, VRL XFC 10 Function 24-bit address bus used by CPU32 Inputs to ADC multiplexer Indicates that a valid address is on the address bus Requests an automatic vector during interrupt acknowledge Indicates that a bus error has occurred Indicates that the MCU has relinquished the bus Indicates that an external device has assumed bus mastership Signals a hardware breakpoint to the CPU Indicates that an external device requires bus mastership System clock output Select external devices at programmed addresses Chip select for external boot start-up ROM 16-bit data bus During a read cycle, indicates when it is possible for an external device to place data on the data bus. During a write cycle, indicates that valid data is on the data bus. Provide asynchronous data transfers and dynamic bus sizing Serial I/O and clock for background debugging mode External M6800 bus clock output Connections for clock synthesizer circuit reference; a crystal or an external oscillator can be used Function Codes Identify processor state and current address space Freeze Indicates that the CPU has entered background mode Halt Suspend external bus activity Instruction Fetch Identifies bus cycles in which operand is loaded into pipeline Instruction Pipeline Indicates instruction pipeline activity Interrupt Request Level Provide prioritized interrupts to the CPU Clock Mode Select Selects the source and type of system clock Port ADA ADC digital input port signals Port C SIM digital output port signals Port E SIM digital I/O port signals Port F SIM digital I/O port signals Quotient Out Provides the quotient bit of the polynomial divider Reset System reset Read-Modify-Write Cycle Indicates an indivisible read-modify-write instruction Read/Write Indicates the direction of data transfer on the bus Size Indicates the number of bytes to be transferred during a bus cycle TPU I/O Channels Bidirectional TPU channels Three-State Control Places all output drivers in a high-impedance state TCR2 Clock TPU clock input ADC Reference Voltage Provide precise reference for A/D conversion External Filter Capacitor Connection for external phase-locked loop filter capacitor MC68334 MC68334TS/D 3 System Integration Module The MCU system integration module (SIM) consists of five functional blocks that control system startup, initialization, configuration, and external bus. SYSTEM CONFIGURATION AND PROTECTION CLOCK SYNTHESIZER CHIP SELECTS CLKOUT EXTAL MODCLK CHIP SELECTS EXTERNAL BUS EXTERNAL BUS INTERFACE RESET FACTORY TEST TSC FREEZE/QUOT S(C)IM BLOCK Figure 4 SIM Block Diagram 3.1 Overview The system configuration and protection block controls MCU configuration and operating mode. The block also provides bus and software watchdog monitors. The system clock generates clock signals used by the SIM, other IMB modules, and external devices. In addition, a periodic interrupt generator supports execution of time-critical control routines. The external bus interface handles the transfer of information between IMB modules and external address space. The chip-select block provides eleven general-purpose chip-select signals and a boot ROM chip select signal. Both general-purpose and boot ROM chip-select signals have associated base address registers and option registers. The system test block incorporates hardware necessary for testing the MCU. It is used to perform factory tests, and its use in normal applications is not supported. The SIM control register address map occupies 128 bytes. Unused registers within the 128-byte address space return zeros when read. The “Access” column in the SIM address map below indicates which registers are accessible only at the supervisor privilege level and which can be assigned to either the supervisor or user privilege level, according to the value of the SUPV bit in the SIMCR. MC68334 MC68334TS/D REV. 1 11 Table 7 SIM Address Map Access S S S S S S S S S/U S/U S/U S S/U S/U S/U S S Address $YFFA00 $YFFA02 $YFFA04 $YFFA06 $YFFA08 $YFFA0A $YFFA0C $YFFA0E $YFFA10 $YFFA12 $YFFA14 $YFFA16 $YFFA18 $YFFA1A $YFFA1C $YFFA1E $YFFA20 S S S S S S S S S S S S S/U $YFFA22 $YFFA24 $YFFA26 $YFFA28 $YFFA2A $YFFA2C $YFFA2E $YFFA30 $YFFA32 $YFFA34 $YFFA36 $YFFA38 $YFFA3A $YFFA3C $YFFA3E $YFFA40 $YFFA42 $YFFA44 $YFFA46 $YFFA48 $YFFA4A $YFFA4C $YFFA4E $YFFA50 $YFFA52 $YFFA54 $YFFA56 $YFFA58 $YFFA5A $YFFA5C S/U S S S S S S S S S S S S S 12 15 8 7 0 SIM MODULE CONFIGURATION REGISTER (SIMCR) FACTORY TEST REGISTER (SIMTR) CLOCK SYNTHESIZER CONTROL REGISTER (SYNCR) NOT USED RESET STATUS REGISTER (RSR) MODULE TEST E (SIMTRE) NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED PORT E DATA (PORTE0) NOT USED PORT E DATA (PORTE1) NOT USED PORT E DATA DIRECTION (DDRE) NOT USED PORT E PIN ASSIGNMENT (PEPAR) NOT USED PORT F DATA (PORTF0) NOT USED PORT F DATA (PORTF1) NOT USED PORT F DATA DIRECTION (DDRF) NOT USED PORT F PIN ASSIGNMENT (PFPAR) NOT USED SYSTEM PROTECTION CONTROL (SYPCR) PERIODIC INTERRUPT CONTROL REGISTER (PICR) PERIODIC INTERRUPT TIMING REGISTER (PITR) NOT USED SOFTWARE SERVICE (SWSR) NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED TEST MODULE MASTER SHIFT A (TSTMSRA) TEST MODULE MASTER SHIFT B (TSTMSRB) TEST MODULE SHIFT COUNT (TSTSC) TEST MODULE REPETITION COUNTER (TSTRC) TEST MODULE CONTROL (CREG) TEST MODULE DISTRIBUTED REGISTER (DREG) NOT USED NOT USED NOT USED NOT USED NOT USED PORT C DATA (PORTC) NOT USED NOT USED CHIP-SELECT PIN ASSIGNMENT (CSPAR0) CHIP-SELECT PIN ASSIGNMENT (CSPAR1) CHIP-SELECT BASE BOOT (CSBARBT) CHIP-SELECT OPTION BOOT (CSORBT) CHIP-SELECT BASE 0 (CSBAR0) CHIP-SELECT OPTION 0 (CSOR0) CHIP-SELECT BASE 1 (CSBAR1) CHIP-SELECT OPTION 1 (CSOR1) CHIP-SELECT BASE 2 (CSBAR2) CHIP-SELECT OPTION 2 (CSOR2) CHIP-SELECT BASE 3 (CSBAR3) CHIP-SELECT OPTION 3 (CSOR3) CHIP-SELECT BASE 4 (CSBAR4) MC68334 MC68334TS/D REV. 1 Table 7 SIM Address Map Access S S S S S S S S S S S S S Address $YFFA5E $YFFA60 $YFFA62 $YFFA64 $YFFA66 $YFFA68 $YFFA6A $YFFA6C $YFFA6E $YFFA70 $YFFA72 $YFFA74 $YFFA76 15 8 7 CHIP-SELECT OPTION 4 (CSOR4) CHIP-SELECT BASE 5 (CSBAR5) CHIP-SELECT OPTION 5 (CSOR5) CHIP-SELECT BASE 6 (CSBAR6) CHIP-SELECT OPTION 6 (CSOR6) CHIP-SELECT BASE 7 (CSBAR7) CHIP-SELECT OPTION 7 (CSOR7) CHIP-SELECT BASE 8 (CSBAR8) CHIP-SELECT OPTION 8 (CSOR8) CHIP-SELECT BASE 9 (CSBAR9) CHIP-SELECT OPTION 9 (CSOR9) CHIP-SELECT BASE 10 (CSBAR10) CHIP-SELECT OPTION 10 (CSOR10) 0 Y = M111, where M is the logic state of the module mapping (MM) bit in the SIMCR. 3.2 System Configuration and Protection Block This functional block provides configuration control for the entire MCU. It also performs interrupt arbitration, bus monitoring, and system test functions. MCU system protection includes a bus monitor, a HALT monitor, a spurious interrupt monitor, and a software watchdog timer. These functions have been made integral to the microcontroller to reduce the number of external components in a complete control system. MC68334 MC68334TS/D REV. 1 13 MODULE CONFIGURATION AND TEST RESET STATUS HALT MONITOR RESET REQUEST BUS MONITOR BERR SPURIOUS INTERRUPT MONITOR SOFTWARE WATCHDOG TIMER CLOCK RESET REQUEST 29 PRESCALER IRQ [7:1] PERIODIC INTERRUPT TIMER SYS PROTECT BLOCK Figure 5 System Configuration and Protection Block 3.2.1 System Configuration The SIM controls MCU configuration during normal operation and during internal testing. SIMCR — SIM Configuration Register $YFFA00 15 14 13 12 11 10 EXOFF FRZSW FRZBM 0 SLVEN 0 0 0 DATA11 0 9 8 SHEN 7 6 5 4 SUPV MM 0 0 1 1 0 0 3 2 1 0 1 1 IARB RESET: 0 0 0 0 1 1 The SIM configuration register controls system configuration. It can be read or written at any time, except for the module mapping (MM) bit, which can be written only once. 14 MC68334 MC68334TS/D REV. 1 EXOFF — External Clock Off 0 = The CLKOUT pin is driven from an internal clock source. 1 = The CLKOUT pin is placed in a high-impedance state. FRZSW — Freeze Software Enable 0 = When FREEZE is asserted, the software watchdog and periodic interrupt timer counters continue to run. 1 = When FREEZE is asserted, the software watchdog and periodic interrupt timer counters are disabled, preventing interrupts during software debug. FRZBM — Freeze Bus Monitor Enable 0 = When FREEZE is asserted, the bus monitor continues to operate. 1 = When FREEZE is asserted, the bus monitor is disabled. SLVEN — Factory Test Mode Enabled This bit is a read-only status bit that reflects the state of DATA11 during reset. 0 = IMB is not available to an external master. 1 = An external bus master has direct access to the IMB. SHEN[1:0] — Show Cycle Enable This field determines what the EBI does with the external bus during internal transfer operations. A show cycle allows internal transfers to be externally monitored. The table below shows whether show cycle data is driven externally, and whether external bus arbitration can occur. To prevent bus conflict, external peripherals must not be enabled during show cycles. SHEN 00 01 10 11 Action Show cycles disabled, external arbitration enabled Show cycles enabled, external arbitration disabled Show cycles enabled, external arbitration enabled Show cycles enabled, external arbitration enabled, internal activity is halted by a bus grant SUPV — Supervisor/Unrestricted Data Space The SUPV bit places the SIM global registers in either supervisor or user data space. 0 = Registers with access controlled by the SUPV bit are accessible from either the user or supervisor privilege level. 1 = Registers with access controlled by the SUPV bit are restricted to supervisor access only. MM — Module Mapping 0 = Internal modules are addressed from $7FF000 – $7FFFFF. 1 = Internal modules are addressed from $FFF000 – $FFFFFF. IARB[3:0] — Interrupt Arbitration Field Each module that can generate interrupt requests has an interrupt arbitration (IARB) field. Arbitration between interrupt requests of the same priority is performed by serial contention between IARB field bit values. Contention must take place whenever an interrupt request is acknowledged, even when there is only a single pending request. An IARB field must have a nonzero value for contention to take place. If an interrupt request from a module with an IARB field value of %0000 is recognized, the CPU processes a spurious interrupt exception. Because the SIM routes external interrupt requests to the CPU, the SIM IARB field value is used for arbitration between internal and external interrupts of the same priority. The reset value of IARB for the SIM is %1111, and the reset IARB value for all other modules is %0000, which prevents SIM interrupts from being discarded during initialization. MC68334 MC68334TS/D REV. 1 15 3.2.2 System Protection Control Register The system protection control register controls system monitor functions, software watchdog clock prescaling, and bus monitor timing. This register can be written only once following power-on or reset, but can be read at any time. SYPCR — System Protection Control Register 15 14 13 12 11 10 9 $YFFA21 8 NOT USED 7 6 SWE SWP 1 MODCLK 5 4 SWT 3 2 HME BME 0 0 1 0 BMT RESET: 0 0 0 0 SWE — Software Watchdog Enable 0 = Software watchdog disabled 1 = Software watchdog enabled SWP — Software Watchdog Prescale This bit controls the value of the software watchdog prescaler. 0 = Software watchdog clock not prescaled 1 = Software watchdog clock prescaled by 512 SWT[1:0] — Software Watchdog Timing This field selects the divide ratio used to establish software watchdog time-out period. The following table gives the ratio for each combination of SWP and SWT bits. SWP 0 SWT 00 Ratio 0 01 211 0 10 213 0 11 215 1 00 218 1 01 220 1 10 222 1 11 224 29 HME — Halt Monitor Enable 0 = Disable halt monitor function 1 = Enable halt monitor function BME — Bus Monitor External Enable 0 = Disable bus monitor function for an internal to external bus cycle. 1 = Enable bus monitor function for an internal to external bus cycle. BMT[1:0] — Bus Monitor Timing This field selects a bus monitor time-out period as shown in the following table. BMT 00 01 10 11 16 Bus Monitor Time-out Period 64 System Clocks 32 System Clocks 16 System Clocks 8 System Clocks MC68334 MC68334TS/D REV. 1 3.2.3 Bus Monitor The internal bus monitor checks for excessively long DSACK response times during normal bus cycles and for excessively long DSACK or AVEC response times during interrupt acknowledge cycles. The monitor asserts BERR if response time is excessive. DSACK and AVEC response times are measured in clock cycles. The maximum allowable response time can be selected by setting the BMT field. The monitor does not check DSACK response on the external bus unless the CPU initiates the bus cycle. The BME bit in the SYPCR enables the internal bus monitor for internal to external bus cycles. If a system contains external bus masters, an external bus monitor must be implemented and the internal to external bus monitor option must be disabled. 3.2.4 Halt Monitor The halt monitor responds to an assertion of HALT on the internal bus. A flag in the reset status register (RSR) indicates that the last reset was caused by the halt monitor. The halt monitor reset can be inhibited by the HME bit in the SYPCR. 3.2.5 Spurious Interrupt Monitor The spurious interrupt monitor issues BERR if no interrupt arbitration occurs during an interrupt-acknowledge cycle. 3.2.6 Software Watchdog The software watchdog is controlled by SWE in the SYPCR. Once enabled, the watchdog requires that a service sequence be written to SWSR on a periodic basis. If servicing does not take place, the watchdog times out and issues a reset. This register can be written at any time, but returns zeros when read. SWSR — Software Service Register 15 14 13 12 11 $YFFA27 10 9 8 NOT USED 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 RESET: Register shown with read value Perform a software watchdog service sequence as follows: • Write $55 to SWSR. • Write $AA to SWSR. Both writes must occur before time-out in the order listed, but any number of instructions can be executed between the two writes. The watchdog clock rate is affected by SWP and SWT in SYPCR. When SWT[1:0] are modified, a watchdog service sequence must be performed before the new time-out period takes effect. The reset value of SWP is affected by the state of the MODCLK pin on the rising edge of reset, as shown in the following table. MODCLK 0 1 MC68334 MC68334TS/D REV. 1 SWP 1 0 17 3.2.7 Periodic Interrupt Timer The periodic interrupt timer (PIT) generates interrupts of specified priorities at specified intervals. Timing for the PIT is provided by a programmable prescaler driven by the system clock. PICR — Periodic Interrupt Control Register 15 14 13 12 11 0 0 0 0 0 0 0 0 0 10 $YFFA22 9 8 7 6 5 4 PIRQL 3 2 1 0 1 1 1 1 PIV RESET: 0 0 0 0 0 0 0 0 This register contains information concerning periodic interrupt priority and vectoring. Bits [10:0] can be read or written at any time. Bits [15:11] are unimplemented and always return zero. PIRQL[2:0] — Periodic Interrupt Request Level The following table shows what interrupt request level is asserted when a periodic interrupt is generated. If a PIT interrupt and an external IRQ signal of the same priority occur simultaneously, the PIT interrupt is serviced first. The periodic timer continues to run when the interrupt is disabled. PIRQL 000 001 010 011 100 101 110 111 Interrupt Request Level Periodic Interrupt Disabled Interrupt Request Level 1 Interrupt Request Level 2 Interrupt Request Level 3 Interrupt Request Level 4 Interrupt Request Level 5 Interrupt Request Level 6 Interrupt Request Level 7 PIV[7:0] — Periodic Interrupt Vector The bits of this field contain the vector generated in response to an interrupt from the periodic timer. When the SIM responds, the periodic interrupt vector is placed on the bus. PITR — Periodic Interrupt Timer Register $YFFA24 15 14 13 12 11 10 9 8 0 0 0 0 0 0 0 PTP 0 0 0 0 0 0 MODCLK 7 6 5 4 3 2 1 0 0 0 0 0 PITM RESET: 0 0 0 0 0 The PITR contains the count value for the periodic timer. A zero value turns off the periodic timer. This register can be read or written at any time. PTP — Periodic Timer Prescaler Control 0 = Periodic timer clock not prescaled 1 = Periodic timer clock prescaled by a value of 512 The reset state of PTP is the complement of the state of the MODCLK signal during reset. 18 MC68334 MC68334TS/D REV. 1 PITM[7:0] — Periodic Interrupt Timing Modulus Field This is an 8-bit timing modulus. The period of the timer can be calculated as follows: ( PITM ) ( Prescale ) ( 4 ) PIT Period = -------------------------------------------------------EXTAL Frequency where PIT Period = Periodic interrupt timer period PITM = Periodic interrupt timer register modulus (PITR[7:0]) EXTAL Frequency = Crystal frequency Prescale = 512 or 1 depending on the state of the PTP bit in the PITR 3.3 System Clock The system clock in the SIM provides timing signals for the IMB modules and for an external peripheral bus. Because the MCU is a fully static design, register and memory contents are not affected when the clock rate changes. System hardware and software support changes in clock rate during operation. The system clock signal can be generated in one of three ways. An internal phase-locked loop can synthesize the clock from either an internal reference or an external reference, or the clock signal can be input from an external frequency source. Keep these clock sources in mind while reading the rest of this section. The figure below is a block diagram of the system clock. EXTAL XTAL CRYSTAL OSCILLATOR PHASE COMPARATOR XFC VDDSYN LOW-PASS FILTER VCO FEEDBACK DIVIDER SYSTEM CLOCK CONTROL CLKOUT W Y X SYSTEM CLOCK 32 PLL BLOCK Figure 6 System Clock Block Diagram 3.3.1 Clock Sources The state of the clock mode (MODCLK) pin during reset determines clock source. When MODCLK is held high during reset, the clock synthesizer generates a clock signal from either an internal or an external reference frequency — the clock synthesizer control register (SYNCR) determines operating frequency and mode of operation. When MODCLK is held low during reset, the clock synthesizer is disabled and an external system clock signal must be applied — SYNCR control bits have no effect. To generate a reference frequency using the internal oscillator a reference crystal must be connected between the EXTAL and XTAL pins. The figure below shows a recommended circuit. MC68334 MC68334TS/D REV. 1 19 C1 22 pF* R1 330k XTAL VSSI C2 22 pF* EXTAL * RESISTANCE AND CAPACITANCE BASED ON A TEST CIRCUIT CONSTRUCTED WITH A DAISHINKU DMX-38 32.768-kHz CRYSTAL. SPECIFIC COMPONENTS MUST BE BASED ON CRYSTAL TYPE. CONTACT CRYSTAL VENDOR FOR EXACT CIRCUIT. 32 OSCILLATOR Figure 7 System Clock Oscillator Circuit If an external reference signal or an external system clock signal is applied via the EXTAL pin, the XTAL pin must be left floating. External reference signal frequency must be less than or equal to maximum specified reference frequency. External system clock signal frequency must be less than or equal to maximum specified system clock frequency. When an external system clock signal is applied (PLL disabled, MODCLK = 0 during reset), the duty cycle of the input is critical, especially at operating frequencies close to maximum. The relationship between clock signal duty cycle and clock signal period is expressed: Minimum External Clock Period = Minimum External Clock High § Low Time ---------------------------------------------------------------------------------------------------------------------------------------------------------------------50% – Percentage Variation of External Clock Input Duty Cycle 3.3.2 Clock Synthesizer Operation VDDSYN is used to power the clock circuits when either an internal or an external reference frequency is applied. A separate power source increases MCU noise immunity and can be used to run the clock when the MCU is powered down. A quiet power supply must be used as the VDDSYN source. Adequate external bypass capacitors should be placed as close as possible to the VDDSYN pin to assure stable operating frequency. When an external system clock signal is applied and the PLL is disabled, VDDSYN should be connected to the VDD supply. Refer to the SIM Reference Manual (SIMRM/AD) for more information regarding system clock power supply conditioning. A voltage controlled oscillator (VCO) generates the system clock signal. To maintain a 50% clock duty cycle, VCO frequency is either two or four times system clock frequency, depending on the state of the X bit in SYNCR. A portion of the clock signal is fed back to a divider/counter. The divider controls the frequency of one input to a phase comparator. The other phase comparator input is a reference signal, either from the crystal oscillator or from an external source. The comparator generates a control signal proportional to the difference in phase between the two inputs. The signal is low-pass filtered and used to correct VCO output frequency. Filter geometry can vary, depending upon the external environment and required clock stability. The figure below shows two recommended filters. XFC pin leakage must be kept within specified limits to maintain optimum stability and PLL performance. An external filter network connected to the XFC pin is not required when an external system clock signal is applied and the PLL is disabled. The XFC pin must be left floating in this case. 20 MC68334 MC68334TS/D REV. 1 C1 0.1µF C3 0.1µF C3 0.1µF C1 0.1µF R1 18kΩ XFC1 VDDSYN VSSI C4 0.01µF VSSI NORMAL OPERATING ENVIRONMENT XFC1, 2 C2 0.01µF C4 0.01µF VDDSYN HIGH-STABILITY OPERATING ENVIRONMENT 1. MAINTAIN LOW LEAKAGE ON THE XFC NODE. 2. RECOMMENDED LOOP FILTER FOR REDUCED SENSITIVITY TO LOW-FREQUENCY NOISE. 16/32 XFC CONN Figure 8 System Clock Filter Networks The synthesizer locks when VCO frequency is equal to EXTAL frequency. Lock time is affected by the filter time constant and by the amount of difference between the two comparator inputs. Whenever comparator input changes, the synthesizer must relock. Lock status is shown by the SLOCK bit in SYNCR. During power-up, the MCU does not come out of reset state until the synthesizer locks. Crystal type, characteristic frequency, and layout of external oscillator circuitry affect lock time. When the clock synthesizer is used, control register SYNCR determines operating frequency and various modes of operation. The SYNCR W bit controls a three-bit prescaler in the feedback divider. Setting W increases VCO speed by a factor of four. The SYNCR Y field determines the count modulus for a modulo 64 down counter, causing it to divide by a value of Y + 1. When W or Y values change, VCO frequency changes, and there is a VCO relock delay. The SYNCR X bit controls a divide-by-two circuit that is not in the synthesizer feedback loop. When X = 0 (reset state), the divider is enabled, and system clock frequency is one-fourth VCO frequency; setting X disables the divider, doubling clock speed without changing VCO speed. There is no relock delay when clock speed is changed by the X bit. Clock frequency is determined by SYNCR bit settings as follows: F SYSTEM = F REFERENCE [ 4 ( Y + 1 ) ( 2 2W + X )] The reset state of SYNCR ($3F00) produces a modulus-64 count. For the device to perform correctly, system clock and VCO frequencies selected by the W, X, and Y bits must be within the limits specified for the MCU. Do not use a combination of bit values that selects either an operating frequency or a VCO frequency greater than the maximum specified values. 3.3.3 External Bus Clock The state of the external clock division bit (EDIV) in SYNCR determines clock rate for the external bus clock signal (ECLK) available on pin ADDR23. ECLK is a bus clock for MC6800 devices and peripherals. ECLK frequency can be set to system clock frequency divided by eight or system clock frequency divided by sixteen. The clock is enabled by the CS10 field in chip select pin assignment register 1 (CSPAR1). ECLK operation during low-power stop is described in the following paragraph. Refer to 3.5 Chip Selects for more information about the external bus clock. MC68334 MC68334TS/D REV. 1 21 3.3.4 Low-Power Operation Low-power operation is initiated by the CPU32. To reduce power consumption selectively, the CPU can set the STOP bits in each module configuration register. To minimize overall microcontroller power consumption, the CPU can execute the LPSTOP instruction, which causes the SIM to turn off the system clock. When individual module STOP bits are set, clock signals inside each module are turned off, but module registers are still accessible. When the CPU executes LPSTOP, a special CPU space bus cycle writes a copy of the current interrupt mask into the clock control logic. The SIM brings the MCU out of low-power operation when either an interrupt of higher priority than the stored mask or a reset occurs. During a low-power stop, unless the system clock signal is supplied by an external source and that source is removed, the SIM clock control logic and the SIM clock signal (SIMCLK) continue to operate. The periodic interrupt timer and input logic for the RESET and IRQ pins are clocked by SIMCLK. The SIM can also continue to generate the CLKOUT signal while in low-power mode. The stop mode system integration module clock (STSIM) and stop mode external clock (STEXT) bits in SYNCR determine clock operation during low-power stop. The table below summarizes the effects of STSIM and STEXT. MODCLK value is the logic level on the MODCLK pin during the last reset before LPSTOP execution. Any clock in the off state is held low. If the synthesizer VCO is turned off during LPSTOP, there is a PLL relock delay after the VCO is turned back on. Table 8 Clock Control Mode LPSTOP No Pins MODCLK 0 Yes 0 Yes 0 Yes 0 Yes 0 No 1 Yes 1 Yes 1 Yes 1 Yes 1 EXTAL External Clock External Clock External Clock External Clock External Clock Crystal or Reference Crystal or Reference Crystal or Reference Crystal or Reference Crystal or Reference SYNCR Bits STSIM STEXT X X 0 0 0 1 1 0 1 1 X X 0 0 0 1 1 1 SIMCLK External Clock External Clock External Clock External Clock External Clock VCO Clock Status CLKOUT External Clock Off ECLK External Clock Off External Clock Off External Clock Off External Clock VCO External Clock VCO Off Off Crystal/ Reference Off Off 0 Crystal or Reference Crystal or Reference VCO 1 VCO VCO VCO Off 3.3.5 Loss of Reference Signal The state of the reset enable (RSTEN) bit in SYNCR determines what happens when clock logic detects a reference failure. When RSTEN is cleared (default state out of reset), the clock synthesizer is forced into an operating condition referred to as limp mode. Limp mode frequency varies from device to device, but maxi- 22 MC68334 MC68334TS/D REV. 1 mum limp frequency does not exceed one half maximum system clock when X = 0, or maximum system clock frequency when X = 1. When RSTEN is set, the SIM resets the MCU. The limp status bit (SLIMP) in SYNCR indicates whether the synthesizer has a reference signal. It is set when a reference failure is detected. 3.3.6 Clock Control The clock control circuits determine system clock frequency and clock operation under special circumstances, such as following loss of synthesizer reference or during low-power operation. Clock source is determined by the logic state of the MODCLK pin during reset. SYNCR — Clock Synthesizer Control Register 15 14 W X 13 12 11 10 9 $YFFA04 8 Y 7 6 5 4 3 2 1 0 EDIV 0 0 SLIMP SLOCK RSTEN STSIM STEXT 0 0 0 U U 0 0 0 RESET: 0 0 1 1 1 1 1 1 When the on-chip clock synthesizer is used, system clock frequency is controlled by the bits in the upper byte of SYNCR. Bits in the lower byte show status of or control operation of internal and external clocks. The SYNCR can be read or written only when the CPU is operating at the supervisor privilege level. W — Frequency Control (VCO) This bit controls a prescaler tap in the synthesizer feedback loop. Setting the bit increases the VCO speed by a factor of four. VCO relock delay is required. X — Frequency Control Bit (Prescale) This bit controls a divide by two prescaler that is not in the synthesizer feedback loop. Setting the bit doubles clock speed without changing the VCO speed. There is no VCO relock delay. Y[5:0] — Frequency Control (Counter) The Y field controls the modulus down counter in the synthesizer feedback loop, causing it to divide by a value of Y + 1. Values range from 0 to 63. VCO relock delay is required. EDIV — E Clock Divide Rate 0 = ECLK frequency is system clock divided by 8. 1 = ECLK frequency is system clock divided by 16. ECLK is an external M6800 bus clock available on pin ADDR23. Refer to 3.5 Chip Selects for more information. SLIMP — Limp Mode Flag 0 = External crystal is VCO reference. 1 = Loss of crystal reference. When the on-chip synthesizer is used, loss of reference frequency causes SLIMP to be set. The VCO continues to run using the base control voltage. Maximum limp frequency is maximum specified system clock frequency. X-bit state affects limp frequency. SLOCK — Synthesizer Lock Flag 0 = VCO is enabled, but has not locked. 1 = VCO has locked on the desired frequency (or system clock is external). The MCU maintains reset state until the synthesizer locks, but SLOCK does not indicate synthesizer lock status until after the user writes to SYNCR. MC68334 MC68334TS/D REV. 1 23 RSTEN — Reset Enable 0 = Loss of crystal causes the MCU to operate in limp mode. 1 = Loss of crystal causes system reset. STSIM — Stop Mode SIM Clock 0 = When LPSTOP is executed, the SIM clock is driven from the crystal oscillator and the VCO is turned off to conserve power. 1 = When LPSTOP is executed, the SIM clock is driven from the VCO. STEXT — Stop Mode External Clock 0 = When LPSTOP is executed, the CLKOUT signal is held negated to conserve power. 1 = When LPSTOP is executed, the CLKOUT signal is driven from the SIM clock, as determined by the state of the STSIM bit. 3.4 External Bus Interface The external bus interface (EBI) transfers information between the internal MCU bus and external devices. The external bus has 24 address lines and 16 data lines. The EBI provides dynamic sizing between 8-bit and 16-bit data accesses. It supports byte, word, and long-word transfers. Ports are accessed through the use of asynchronous cycles controlled by the data transfer (SIZ1 and SIZ0) and data size acknowledge pins (DSACK1 and DSACK0). Multiple bus cycles may be required for a transfer to or from an 8-bit port. Port width is the maximum number of bits accepted or provided during a bus transfer. External devices must follow the handshake protocol described below. Control signals indicate the beginning of the cycle, the address space, the size of the transfer, and the type of cycle. The selected device controls the length of the cycle. Strobe signals, one for the address bus and another for the data bus, indicate the validity of an address and provide timing information for data. The EBI operates in an asynchronous mode for any port width. To add flexibility and minimize the necessity for external logic, MCU chip-select logic can be synchronized with EBI transfers. Chip-select logic can also provide internally-generated bus control signals for these accesses. Refer to 3.5 Chip Selects for more information. 3.4.1 Bus Control Signals The CPU initiates a bus cycle by driving the address, size, function code, and read/write outputs. At the beginning of the cycle, size signals SIZ0 and SIZ1 are driven along with the function code signals. The size signals indicate the number of bytes remaining to be transferred during an operand cycle. They are valid while the address strobe (AS) is asserted. The following table shows SIZ0 and SIZ1 encoding. The read/write (R/W) signal determines the direction of the transfer during a bus cycle. This signal changes state, when required, at the beginning of a bus cycle, and is valid while AS is asserted. R/W only changes state when a write cycle is preceded by a read cycle or vice versa. The signal can remain low for two consecutive write cycles. Table 9 Size Signal Encoding SIZ1 0 1 1 0 24 SIZ0 1 0 1 0 Transfer Size Byte Word 3 Byte Long Word MC68334 MC68334TS/D REV. 1 3.4.2 Function Codes The CPU32 automatically generates function code signals FC[2:0]. The function codes can be considered address extensions that automatically select one of eight address spaces to which an address applies. These spaces are designated as either user or supervisor, and program or data spaces. Address space seven is designated CPU space. CPU space is used for control information not normally associated with read or write bus cycles. Function codes are valid while AS is asserted. Table 10 CPU32 Address Space Encoding FC2 0 0 0 0 1 1 1 1 FC1 0 0 1 1 0 0 1 1 FC0 0 1 0 1 0 1 0 1 Address Space Reserved User Data Space User Program Space Reserved Reserved Supervisor Data Space Supervisor Program Space CPU Space 3.4.3 Address Bus Address bus signals ADDR[23:0] define the address of the most significant byte to be transferred during a bus cycle. The MCU places the address on the bus at the beginning of a bus cycle. The address is valid while AS is asserted. 3.4.4 Address Strobe AS is a timing signal that indicates the validity of an address on the address bus and the validity of many control signals. It is asserted one-half clock after the beginning of a bus cycle. 3.4.5 Data Bus Data bus signals DATA[15:0] make up a bidirectional, nonmultiplexed parallel bus that transfers data to or from the MCU. A read or write operation can transfer 8 or 16 bits of data in one bus cycle. During a read cycle, the data is latched by the MCU on the last falling edge of the clock for that bus cycle. For a write cycle, all 16 bits of the data bus are driven, regardless of the port width or operand size. The MCU places the data on the data bus one-half clock cycle after AS is asserted in a write cycle. 3.4.6 Data Strobe Data strobe (DS) is a timing signal. For a read cycle, the MCU asserts DS to signal an external device to place data on the bus. DS is asserted at the same time as AS during a read cycle. For a write cycle, DS signals an external device that data on the bus is valid. The MCU asserts DS one full clock cycle after the assertion of AS during a write cycle. 3.4.7 Bus Cycle Termination Signals During bus cycles, external devices assert the data transfer and size acknowledge signals (DSACK1 and DSACK0). During a read cycle, the signals tell the MCU to terminate the bus cycle and to latch data. During a write cycle, the signals indicate that an external device has successfully stored data and that the cycle can end. These signals also indicate to the MCU the size of the port for the bus cycle just completed. (Refer to 3.4.9 Dynamic Bus Sizing). The bus error (BERR) signal is also a bus cycle termination indicator and can be used in the absence of DSACK1 and DSACK0 to indicate a bus error condition. It can also be asserted in conjunction with these signals, provided it meets the appropriate timing requirements. The internal bus monitor can be used to generate the BERR signal for internal and internal-to-external transfers. When BERR and HALT are asserted simultaneously, the CPU takes a bus error exception. MC68334 MC68334TS/D REV. 1 25 Autovector signal (AVEC) can terminate external IRQ pin interrupt acknowledge cycles. AVEC indicates that the MCU will internally generate a vector number to locate an interrupt handler routine. If it is continuously asserted, autovectors will be generated for all external interrupt requests. AVEC is ignored during all other bus cycles. 3.4.8 Data Transfer Mechanism The MCU architecture supports byte, word, and long-word operands, allowing access to 8- and 16-bit data ports through the use of asynchronous cycles controlled by the data transfer and size acknowledge inputs (DSACK1 and DSACK0). 3.4.9 Dynamic Bus Sizing The MCU dynamically interprets the port size of the addressed device during each bus cycle, allowing operand transfers to or from 8- and 16-bit ports. During an operand transfer cycle, the slave device signals its port size and indicates completion of the bus cycle to the MCU through the use of the DSACK0 and DSACK1 inputs, as shown in the following table. Table 11 Effect of DSACK Signals DSACK1 1 1 0 0 DSACK0 1 0 1 0 Result Insert Wait States in Current Bus Cycle Complete Cycle — Data Bus Port Size is 8 Bits Complete Cycle — Data Bus Port Size is 16 Bits Reserved For example, if the MCU is executing an instruction that reads a long-word operand from a 16-bit port, the MCU latches the 16 bits of valid data and then runs another bus cycle to obtain the other 16 bits. The operation for an 8-bit port is similar, but requires four read cycles. The addressed device uses the DSACK0 and DSACK1 signals to indicate the port width. For instance, a 16-bit device always returns DSACK0 = 1 and DSACK1 = 0 for a 16-bit port, regardless of whether the bus cycle is a byte or word operation. Dynamic bus sizing requires that the portion of the data bus used for a transfer to or from a particular port size be fixed. A 16-bit port must reside on data bus bits [15:0] and an 8-bit port must reside on data bus bits [15:8]. This minimizes the number of bus cycles needed to transfer data and ensures that the MCU transfers valid data. The MCU always attempts to transfer the maximum amount of data on all bus cycles. For a word operation, it is assumed that the port is 16 bits wide when the bus cycle begins. Operand bytes are designated as shown in the following figure. OP0 is the most significant byte of a long-word operand, and OP3 is the least significant byte. The two bytes of a word-length operand are OP0 (most significant) and OP1. The single byte of a byte-length operand is OP0. Operand Byte Order 31 Long Word Three Byte Word 24 OP0 23 16 15 8 7 0 OP1 OP2 OP3 OP0 OP1 OP2 OP0 Byte OP1 OP0 Figure 9 Operand Byte Order 26 MC68334 MC68334TS/D REV. 1 3.4.10 Operand Alignment The data multiplexer establishes the necessary connections for different combinations of address and data sizes. The multiplexer takes the two bytes of the 16-bit bus and routes them to their required positions. Positioning of bytes is determined by the size and address outputs. SIZ1 and SIZ0 indicate the remaining number of bytes to be transferred during the current bus cycle. The number of bytes transferred is equal to or less than the size indicated by SIZ1 and SIZ0, depending on port width. ADDR0 also affects the operation of the data multiplexer. During an operand transfer, ADDR[23:1] indicate the word base address of the portion of the operand to be accessed, and ADDR0 indicates the byte offset from the base. 3.4.11 Misaligned Operands CPU32 processor architecture uses a basic operand size of 16 bits. An operand is misaligned when it overlaps a word boundary. This is determined by the value of ADDR0. When ADDR0 = 0 (an even address), the address is on a word and byte boundary. When ADDR0 = 1 (an odd address), the address is on a byte boundary only. A byte operand is aligned at any address; a word or long-word operand is misaligned at an odd address. The MCU does not support misaligned operand transfers. The largest amount of data that can be transferred by a single bus cycle is an aligned word. If the MCU transfers a long-word operand via a 16-bit port, the most significant operand word is transferred on the first bus cycle and the least significant operand word on a following bus cycle. 3.4.12 Operand Transfer Cases The following table summarizes how operands are aligned for various types of transfers. OPn entries are portions of a requested operand that are read or written during a bus cycle and are defined by SIZ1, SIZ0, and ADDR0 for that bus cycle. Table 12 Operand Alignment Transfer Case SIZ1 SIZ0 ADDR0 DSACK1 DSACK0 0 0 0 1 1 1 1 1 0 0 X 0 1 0 1 1 0 0 1 1 Word to 16-Bit Port (Misaligned)2 1 1 0 0 0 1 3 Byte to 8-Bit Port (Aligned)3 1 1 3 Byte to 8-Bit Port (Misaligned)2, 3 1 1 3 Byte to 16-Bit Port (Aligned)3 1 3 Byte to 16-Bit Port (Misaligned)2, 3 1 Long Word to 8-Bit Port (Aligned) Byte to 8-Bit Port (Even/Odd) Byte to 16-Bit Port (Even) Byte to 16-Bit Port (Odd) Word to 8-Bit Port (Aligned) Word to 8-Bit Port (Misaligned)2 Word to 16-Bit Port (Aligned) Long Word to 8-Bit Port (Misaligned)2 Long Word to 16-Bit Port (Aligned) Long Word to 16-Bit Port (Misaligned)2 0 X X 0 0 DATA [15:8] OP0 OP0 (OP0) OP0 OP0 DATA [7:0] (OP0)1 (OP0) OP0 (OP1) (OP0) 0 0 X X OP0 (OP0) OP1 OP0 0 1 0 OP0 (OP1) 1 1 0 OP0 (OP0) 1 0 0 X OP0 OP1 1 1 0 X (OP0) OP0 0 1 0 0 0 1 1 1 0 0 OP0 OP0 (OP1) (OP0) 0 1 0 0 0 1 0 0 X X OP0 (OP0) OP1 OP0 1. Operands in parentheses are ignored by the CPU32 during read cycles. 2. The CPU32 does not support misaligned word or long-word transfers. 3. Three-byte transfer cases occur only as a result of a long word to byte transfer. MC68334 MC68334TS/D REV. 1 27 3.5 Chip Selects Typical microcontrollers require additional hardware to provide external chip-select and address decode signals. The MCU includes 12 programmable chip-select circuits that can provide 2- to 20-clockcycle access to external memory and peripherals. Address block sizes of two Kbytes to one Mbyte can be selected. The figure below is a functional diagram of a chip-select circuit. Chip-select assertion can be synchronized with bus control signals to provide output enable, read/write strobe, or interrupt acknowledge signals. Chip select logic can also generate DSACK and AVEC signals internally. Each signal can also be synchronized with the ECLK signal available on ADDR23. INTERNAL SIGNALS BASE ADDRESS REGISTER ADDRESS ADDRESS COMPARATOR BUS CONTROL OPTION COMPARE TIMING AND CONTROL PIN OPTION REGISTER AVEC AVEC GENERATOR DSACK GENERATOR PIN ASSIGNMENT REGISTER PIN DATA REGISTER DSACK CHIP SEL BLOCK Figure 10 Chip-Select Circuit Block Diagram When a memory access occurs, chip-select logic compares address space type, address, type of access, transfer size, and interrupt priority (in the case of interrupt acknowledge) to parameters stored in chip-select registers. If all parameters match, the appropriate chip-select signal is asserted. Select signals are active low. If a chip-select function is given the same address as a microcontroller module or an internal memory array, an access to that address goes to the module or array, and the chip-select signal is not asserted. The external address and data buses do not reflect the internal access. All chip-select circuits are configured for operation out of reset. However, all chip-select signals except CSBOOT are disabled, and cannot be asserted until the BYTE field in the corresponding option register is programmed to a nonzero value, selecting a transfer size. The chip-select option register must not be written until a base address has been written to a proper base address register. CSBOOT is automatically asserted out of reset. Alternate functions for chip-select pins are enabled if appropriate data bus pins are held low at the release of the reset signal. The following table lists allocation of chip-selects and discrete outputs on the pins of the MCU. 28 MC68334 MC68334TS/D REV. 1 Table 13 Chip Select Allocation Pin CSBOOT BR BG BGACK FC0 FC1 FC2 ADDR19 ADDR20 ADDR21 ADDR22 ADDR23 Chip Select CSBOOT CS0 CS1 CS2 CS3 CS4 CS5 CS6 CS7 CS8 CS9 CS10 Discrete Outputs — — — — PC0 PC1 PC2 PC3 PC4 PC5 PC6 ECLK 3.5.1 Chip-Select Registers Each chip-select pin can have one or more functions. Chip-select pin assignment registers (CSPAR[0:1]) determine functions of the pins. Pin assignment registers also determine port size (8- or 16bit) for dynamic bus allocation. A pin data register (PORTC) latches data for chip-select pins that are used for discrete output. Blocks of addresses are assigned to each chip-select function. Block sizes of two Kbytes to one Mbyte can be selected by writing values to the appropriate base address register (CSBAR[0:10], CSBARBT). Address blocks for separate chip-select functions can overlap. Chip select option registers (CSOR[0:10], CSORBT) determine timing of and conditions for assertion of chip-select signals. Eight parameters, including operating mode, access size, synchronization, and wait state insertion can be specified. Initialization software usually resides in a peripheral memory device controlled by the chip-select circuits. A set of special chip-select functions and registers (CSORBT, CSBARBT) is provided to support bootstrap operation. 3.5.2 Pin Assignment Registers The pin assignment registers contain twelve 2-bit fields (CS[10:0] and CSBOOT) that determine functions of the chip-select pins. Each pin has two or three possible functions, as shown below. Table 14 Chip-Select Pin Functions Assignment Register CSPAR0 CSPAR1 MC68334 MC68334TS/D REV. 1 16-Bit Chip Select CSBOOT CS0 CS1 CS2 CS3 CS4 CS5 CS6 CS7 CS8 CS9 CS10 8-Bit Chip Select CSBOOT CS0 CS1 CS2 CS3 CS4 CS5 CS6 CS7 CS8 CS9 CS10 Alternate Function CSBOOT BR BG BGACK FC0 FC1 FC2 ADDR19 ADDR20 ADDR21 ADDR22 ADDR23 Discrete Output — — — — PC0 PC1 PC2 PC3 PC4 PC5 PC6 ECLK 29 The table below shows pin assignment field encoding. Pins that have no discrete output function do not use the %00 encoding. Table 15 Pin Assignment Encodings Bit Field 00 01 10 11 Description Discrete Output Alternate Function Chip Select (8-Bit Port) Chip Select (16-Bit Port) CSPAR0 — Chip Select Pin Assignment Register 0 15 14 0 0 13 12 CSPA0[6] 11 10 CSPA0[5] 9 8 CSPA0[4] $YFFA44 7 6 CSPA0[3] 5 4 CSPA0[2] 3 2 CSPA0[1] 1 0 CSBOOT RESET: 0 0 DATA2 1 DATA2 1 DATA2 1 DATA1 1 DATA1 1 DATA1 1 1 DATA0 CSPAR0 contains seven 2-bit fields that determine the functions of corresponding chip-select pins. CSPAR0[15:14] are not used. These bits always read zero; writes have no effect. CSPAR0 bit 1 always reads one; writes to CSPAR0 bit 1 have no effect. Table 16 CSPAR0 Pin Assignments CSPAR0 Field CSPA0[6] CSPA0[5] CSPA0[4] CSPA0[3] CSPA0[2] CSPA0[1] CSBOOT Chip Select Signal CS5 CS4 CS3 CS2 CS1 CS0 CSBOOT Alternate Signal FC2 FC1 FC0 BGACK BG BR — Discrete Output PC2 PC1 PC0 — — — — CSPAR1 — Chip Select Pin Assignment Register 1 15 14 13 12 11 10 9 8 0 0 0 0 0 0 CSPA1[4] 0 0 0 0 0 $YFFA46 7 6 CSPA1[3] 5 4 CSPA1[2] 3 2 CSPA1[1] 1 0 CSPA1[0] RESET: 0 DATA7 1 DATA [7:6] 1 DATA [7:5] 1 DATA [7:4] 1 DATA [7:3] 1 CSPAR1 contains five 2-bit fields that determine the functions of corresponding chip-select pins. CSPAR1[15:10] are not used. These bits always read zero; writes have no effect. Table 17 CSPAR1 Pin Assignments CSPAR1 Field CSPA1[4] CSPA1[3] CSPA1[2] CSPA1[1] CSPA1[0] 30 Chip Select Signal CS10 CS9 CS8 CS7 CS6 Alternate Signal ADDR23 ADDR22 ADDR21 ADDR20 ADDR19 Discrete Output ECLK PC6 PC5 PC4 PC3 MC68334 MC68334TS/D REV. 1 Port size determines the way in which bus transfers to an external address are allocated. Port size of eight bits or sixteen bits can be selected when a pin is assigned as a chip select. Port size and transfer size affect how the chip-select signal is asserted. Refer to 3.5.4 Option Registers for more information. Out of reset, chip-select pin function is determined by the logic level on a corresponding data bus pin. These pins have weak internal pull-up drivers, but can be held low by external devices. Either 16-bit chip-select function (%11) or alternate function (%01) can be selected during reset. All pins except the boot ROM select pin (CSBOOT) are disabled out of reset. There are twelve chip-select functions and only eight associated data bus pins. There is not a one-to-one correspondence. The table below shows reset states. Table 18 Reset Pin Function of CS[10:6] DATA7 1 1 1 1 1 0 Data Bus Pins at Reset DATA6 DATA5 DATA4 1 1 1 1 0 X 1 1 1 0 X X 1 1 0 X X X DATA3 1 0 X X X X Chip-Select/Address Bus Pin Function CS10/ CS9/ CS8/ CS7/ CS6/ ADDR23 ADDR22 ADDR21 ADDR20 ADDR19 CS10 CS9 CS8 CS7 CS6 CS10 CS9 CS8 CS7 ADDR19 CS10 CS9 CS8 ADDR20 ADDR19 CS10 CS9 ADDR21 ADDR20 ADDR19 CS10 ADDR22 ADDR21 ADDR20 ADDR19 ADDR23 ADDR22 ADDR21 ADDR20 ADDR19 The CSBOOT signal is normally enabled out of reset. The state of the DATA0 line during reset determines what port width CSBOOT uses. If DATA0 is held high (either by the weak internal pull-up driver or by an external pull-up device), 16-bit width is selected. If DATA0 is held low, 8-bit port size is selected. A pin programmed as a discrete output drives an external signal to the value specified in the pin data register. No discrete output function is available on pins CSBOOT, BR, BG, or BGACK. ADDR23 provides ECLK output rather than a discrete output signal. When a pin is programmed for discrete output or alternate function, internal chip-select logic still functions and can be used to generate DSACK or AVEC internally on an address and control signal match. 3.5.3 Base Address Registers Each chip select has an associated base address register. A base address is the lowest address in the block of addresses enabled by a chip select. Block size is the extent of the address block above the base address. Block size is determined by the value contained in a BLKSZ field. Block addresses for different chip selects can overlap. The BLKSZ field determines which bits in the base address field are compared to corresponding bits on the address bus during an access. Provided other constraints determined by option register fields are also satisfied, when a match occurs, the associated chip-select signal is asserted. The chip-select address compare logic uses only the most significant bits to match an address within a block. The value of the base address must be a multiple of block size. Base address register diagrams show how base register bits correspond to address lines. After reset, the MCU fetches the initialization routine from the address contained in the reset vector, located beginning at address $000000 of program space. To support bootstrap operation from reset, the base address field in chip-select base address register boot (CSBARBT) has a reset value of all zeros. A memory device containing the reset vector and initialization routine can be automatically enabled by CSBOOT after a reset. The block size field in CSBARBT has a reset value of 512 Kbytes. MC68334 MC68334TS/D REV. 1 31 CSBARBT — Chip-Select Base Address Register Boot ROM $YFFA48 15 14 13 12 11 10 9 8 7 6 5 4 3 2 ADDR 23 ADDR 22 ADDR 21 ADDR 20 ADDR 19 ADDR 18 ADDR 17 ADDR 16 ADDR 15 ADDR 14 ADDR 13 ADDR 12 ADDR 11 0 0 0 0 0 0 0 0 0 0 0 0 1 0 BLKSZ RESET: 0 CSBAR[10:0] — Chip-Select Base Address Registers 1 1 1 $YFFA4C–$YFFA74 15 14 13 12 11 10 9 8 7 6 5 4 3 ADDR 23 ADDR 22 ADDR 21 ADDR 20 ADDR 19 ADDR 18 ADDR 17 ADDR 16 ADDR 15 ADDR 14 ADDR 13 ADDR 12 ADDR 11 2 0 0 0 0 0 0 0 0 0 0 0 1 0 BLKSZ RESET: 0 0 0 0 0 BLKSZ — Block Size Field This field determines the size of the block that must be enabled by the chip select. The following table shows bit encoding for the base address registers block size field. Block Size Field 000 001 010 011 100 101 110 111 Block Size 2 Kbytes 8 Kbytes 16 Kbytes 64 Kbytes 128 Kbytes 256 Kbytes 512 Kbytes 1 Mbyte Address Lines Compared ADDR[23:11] ADDR[23:13] ADDR[23:14] ADDR[23:16] ADDR[23:17] ADDR[23:18] ADDR[23:19] ADDR[23:20] ADDR[23:11] — Base Address Field This field sets the starting address of a particular address space. The address compare logic uses only the most significant bits to match an address within a block. The value of the base address must be a multiple of block size. Base address register diagrams show how base register bits correspond to address lines. 3.5.4 Option Registers The option registers contain eight fields that determine timing of and conditions for assertion of chipselect signals. To assert a chip-select signal, and to provide DSACK or autovector support, other constraints set by fields in the option register and in the base address register must also be satisfied. CSORBT — Chip-Select Option Register Boot ROM 15 14 MODE 13 12 BYTE 11 R/W 10 9 8 $YFFA4A 7 6 5 DSACK STRB 4 3 SPACE 2 1 0 AVEC IPL RESET: 0 1 1 1 1 0 1 1 0 1 1 1 0 CSOR[10:0] — Chip-Select Option Registers 15 14 MODE 13 12 BYTE 11 R/W 10 9 0 0 $YFFA4E–$YFFA76 8 7 6 5 DSACK STRB 0 4 3 SPACE 2 1 0 AVEC IPL RESET: 0 32 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 MC68334 MC68334TS/D REV. 1 CSORBT, the option register for CSBOOT, contains special reset values that support bootstrap operations from peripheral memory devices. The following bit descriptions apply to both CSORBT and CSOR[10:0] option registers. MODE — Asynchronous/Synchronous Mode 0 = Asynchronous mode selected (chip-select assertion determined by internal or external bus control signals) 1 = Synchronous mode selected (chip-select assertion synchronized with ECLK signal) In asynchronous mode, the chip select is asserted synchronized with AS or DS. The DSACK field is not used in synchronous mode because a bus cycle is only performed as a synchronous operation. When a match condition occurs on a chip select programmed for synchronous operation, the chip select signals the EBI that an ECLK cycle is pending. BYTE — Upper/Lower Byte Option This field is used only when the chip-select 16-bit port option is selected in the pin assignment register. The following table lists upper/lower byte options. Byte 00 01 10 11 Description Disable Lower Byte Upper Byte Both Bytes R/W — Read/Write This field causes a chip select to be asserted only for a read, only for a write, or for both read and write. Refer to the following table for options available. R/W 00 01 10 11 Description Reserved Read Only Write Only Read/Write STRB — Address Strobe/Data Strobe 0 = Address strobe 1 = Data strobe This bit controls the timing for assertion of a chip select in asynchronous mode. Selecting address strobe causes chip select to be asserted synchronized with address strobe. Selecting data strobe causes chip select to be asserted synchronized with data strobe. DSACK — Data and Size Acknowledge This field specifies the source of DSACK in asynchronous mode. It also allows the user to adjust bus timing with internal DSACK generation by controlling the number of wait states that are inserted to optimize bus speed in a particular application. The following table shows the DSACK field encoding. The fast termination encoding (1110) is used for two-cycle access to external memory. MC68334 MC68334TS/D REV. 1 33 DSACK 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 Description No Wait States 1 Wait State 2 Wait States 3 Wait States 4 Wait States 5 Wait States 6 Wait States 7 Wait States 8 Wait States 9 Wait States 10 Wait States 11 Wait States 12 Wait States 13 Wait States Fast Termination External DSACK SPACE — Address Space Use this option field to select an address space for the chip-select logic. The CPU32 normally operates in supervisor or user space, but interrupt acknowledge cycles must take place in CPU space. Space 00 01 10 11 Address Space CPU Space User Space Supervisor Space Supervisor/User Space IPL — Interrupt Priority Level If the space field is set for CPU space (00), chip-select logic can be used for interrupt acknowledge. During an interrupt acknowledge cycle, the priority level on address lines ADDR[3:1] is compared to the value in the IPL field. If the values are the same, a chip select is asserted, provided that other option register conditions are met. The following table shows IPL field encoding. IPL 000 001 010 011 100 101 110 111 Description Any Level IPL1 IPL2 IPL3 IPL4 IPL5 IPL6 IPL7 This field only affects the response of chip selects and does not affect interrupt recognition by the CPU. Any level means that chip select is asserted regardless of the level of the interrupt acknowledge cycle. AVEC — Autovector Enable 0 = External interrupt vector enabled 1 = Autovector enabled This field selects one of two methods of acquiring an interrupt vector number during an external interrupt acknowledge cycle. 34 MC68334 MC68334TS/D REV. 1 If the chip select is configured to trigger on an interrupt acknowledge cycle (SPACE = 00) and the AVEC field is set to one, the chip select circuit generates an internal AVEC signal in response to an external interrupt cycle, and the SIM supplies an automatic vector number. Otherwise, the vector number must be supplied by the requesting device. An internal autovector is generated only in response to interrupt requests from the SIM IRQ pins — interrupt requests from other IMB modules are ignored. The AVEC bit must not be used in synchronous mode, as autovector response timing can vary because of ECLK synchronization. 3.5.5 Port C Data Register Bit values in port C determine the state of chip-select pins used for discrete output. When a pin is assigned as a discrete output, the value in this register appears at the output. This is a read/write register. Bit 7 is not used. Writing to this bit has no effect, and it always returns zero when read. PORTC — Port C Data Register 15 14 13 12 11 $YFFA41 10 9 8 NOT USED 7 6 5 4 3 2 1 0 0 PC6 PC5 PC4 PC3 PC2 PC1 PC0 0 1 1 1 1 1 1 1 RESET: 3.6 General-Purpose Input/Output SIM pins can be configured as two general-purpose I/O ports, E and F. The following paragraphs describe registers that control the ports. PORTE0, PORTE1 — Port E Data Register 15 14 13 12 11 10 9 $YFFA11, $YFFA13 8 NOT USED 7 6 5 4 3 2 1 0 PE7 PE6 PE5 PE4 PE3 PE2 PE1 PE0 U U U U U U U U RESET: A write to the port E data register is stored in the internal data latch and, if any port E pin is configured as an output, the value stored for that bit is driven on the pin. A read of the port E data register returns the value at the pin only if the pin is configured as a discrete input. Otherwise, the value read is the value stored in the register. The port E data register is a single register that can be accessed in two locations. When accessed at $YFFA11, the register is referred to as PORTE0; when accessed at $YFFA13, the register is referred to as PORTE1. The register can be read or written at any time. It is unaffected by reset. DDRE — Port E Data Direction Register 15 14 13 12 11 NOT USED 10 $YFFA15 9 8 7 6 5 4 3 2 1 0 DDE7 DDE6 DDE5 DDE4 DDE3 DDE2 DDE1 DDE0 0 0 0 0 0 0 0 0 RESET: The bits in this register control the direction of the pin drivers when the pins are configured as I/O. Any bit in this register set to one configures the corresponding pin as an output. Any bit in this register cleared to zero configures the corresponding pin as an input. This register can be read or written at any time. MC68334 MC68334TS/D REV. 1 35 PEPAR — Port E Pin Assignment Register 15 14 13 12 11 10 $YFFA17 9 8 NOT USED 7 6 5 4 3 2 1 0 PEPA7 PEPA6 PEPA5 PEPA4 PEPA3 PEPA2 PEPA1 PEPA0 RESET: DATA8 DATA8 DATA8 DATA8 DATA8 DATA8 DATA8 DATA8 The bits in this register control the function of each port E pin. Any bit set to one configures the corresponding pin as a bus control signal, with the function shown in the following table. Any bit cleared to zero defines the corresponding pin to be an I/O pin, controlled by PORTE and DDRE. Data bus bit 8 controls the state of this register following reset. If DATA8 is set to one during reset, the register is set to $FF, which defines all port E pins as bus control signals. If DATA8 is cleared to zero during reset, this register is set to $00, configuring all port E pins as I/O pins. Any bit cleared to zero defines the corresponding pin to be an I/O pin. Any bit set to one defines the corresponding pin to be a bus control signal. Table 19 Port E Pin Assignments PEPAR Bit PEPA7 PEPA6 PEPA5 PEPA4 PEPA3 PEPA2 PEPA1 PEPA0 Port E Signal PE7 PE6 PE5 PE4 PE3 PE2 PE1 PE0 Bus Control Signal SIZ1 SIZ0 AS DS RMC AVEC DSACK1 DSACK0 PORTF0, PORTF1 — Port F Data Register 15 14 13 12 11 10 $YFFA19, $YFFA1B 9 8 NOT USED 7 6 5 4 3 2 1 0 PF7 PF6 PF5 PF4 PF3 PF2 PF1 PF0 U U U U U U U U RESET: The write to the port F data register is stored in the internal data latch, and if any port F pin is configured as an output, the value stored for that bit is driven onto the pin. A read of the port F data register returns the value at the pin only if the pin is configured as a discrete input. Otherwise, the value read is the value stored in the register. The port F data register is a single register that can be accessed in two locations. When accessed at $YFFA19, the register is referred to as PORTF0; when accessed at $YFFA1B, the register is referred to as PORTF1. The register can be read or written at any time. It is unaffected by reset. DDRF — Port F Data Direction Register 15 14 13 12 11 NOT USED 10 $YFFA1D 9 8 7 6 5 4 3 2 1 0 DDF7 DDF6 DDF5 DDF4 DDF3 DDF2 DDF1 DDF0 0 0 0 0 0 0 0 0 RESET: The bits in this register control the direction of the pin drivers when the pins are configured for I/O. Any bit in this register set to one configures the corresponding pin as an output. Any bit in this register cleared to zero configures the corresponding pin as an input. 36 MC68334 MC68334TS/D REV. 1 PFPAR — Port F Pin Assignment Register 15 14 13 12 11 NOT USED 10 $YFFA1F 9 8 7 6 5 4 3 2 1 0 PFPA7 PFPA6 PFPA5 PFPA4 PFPA3 PFPA2 PFPA1 PFPA0 RESET: DATA9 DATA9 DATA9 DATA9 DATA9 DATA9 DATA9 DATA9 The bits in this register control the function of each port F pin. Any bit cleared to zero defines the corresponding pin to be an I/O pin. Any bit set to one defines the corresponding pin to be an interrupt request signal or MODCLK. The MODCLK signal has no function after reset. Table 20 Port F Pin Assignments PFPAR Field PFPA7 PFPA6 PFPA5 PFPA4 PFPA3 PFPA2 PFPA1 PFPA0 Port F Signal PF7 PF6 PF5 PF4 PF3 PF2 PF1 PF0 Alternate Signal IRQ7 IRQ6 IRQ5 IRQ4 IRQ3 IRQ2 IRQ1 MODCLK Data bus pin 9 controls the state of this register following reset. If DATA9 is set to one during reset, the register is set to $FF, which defines all port F pins as interrupt request inputs. If DATA9 is cleared to zero during reset, this register is set to $00, defining all port F pins as I/O pins. 3.7 Resets Reset procedures handle system initialization and recovery from catastrophic failure. The MCU performs resets with a combination of hardware and software. The system integration module determines whether a reset is valid, asserts control signals, performs basic system configuration based on hardware mode-select inputs, then passes control to the CPU. Reset occurs when an active low logic level on the RESET pin is clocked into the SIM. Resets are gated by the CLKOUT signal. Asynchronous resets are assumed to be catastrophic. An asynchronous reset can occur on any clock edge. Synchronous resets are timed to occur at the end of bus cycles. If there is no clock when RESET is asserted, reset does not occur until the clock starts. Resets are clocked in order to allow completion of write cycles in progress at the time RESET is asserted. Reset is the highest-priority CPU32 exception. Any processing in progress is aborted by the reset exception, and cannot be restarted. Only essential tasks are performed during reset exception processing. Other initialization tasks must be accomplished by the exception handler routine. 3.7.1 SIM Reset Mode Selection The logic states of certain data bus pins during reset determine SIM operating configuration. In addition, the state of the MODCLK pin determines system clock source and the state of the BKPT pin determines what happens during subsequent breakpoint assertions. The following table is a summary of reset mode selection options. MC68334 MC68334TS/D REV. 1 37 Table 21 Reset Mode Selection Mode Select Pin DATA0 DATA1 DATA2 DATA3 DATA4 DATA5 DATA6 DATA7 DATA8 DATA9 DATA11 MODCLK BKPT Default Function (Pin Left High) CSBOOT 16-Bit CS0 CS1 CS2 CS3 CS4 CS5 CS6 CS[7:6] CS[8:6] CS[9:6] CS[10:6] DSACK0, DSACK1, AVEC, DS, AS, SIZ[1:0] IRQ[7:1] MODCLK Test Mode Disabled VCO = System Clock Background Mode Disabled Alternate Function (Pin Pulled Low) CSBOOT 8-Bit BR BG BGACK FC0 FC1 FC2 ADDR19 ADDR[20:19] ADDR[21:19] ADDR[22:19] ADDR[23:19] PORTE PORTF Test Mode Enabled EXTAL = System Clock Background Mode Enabled Data lines have weak internal pull-up drivers. External bus loading can overcome the weak internal pullup drivers on data bus lines, and hold pins low during reset. Use an active device to hold data bus lines low. Data bus configuration logic must release the bus before the first bus cycle after reset to prevent conflict with external memory devices. The first bus cycle occurs ten CLKOUT cycles after RESET is released. If external mode selection logic causes a conflict of this type, an isolation resistor on the driven lines may be required. 3.7.2 Functions of Pins for Other Modules During Reset Generally, pins associated with modules other than the SIM default to port functions, and input/output ports are set to input state. This is accomplished by disabling pin functions in the appropriate control registers, and by clearing the appropriate port data direction registers. Refer to individual module sections in this manual for more information. The following table is a summary of module pin function out of reset. Table 22 Module Pin Functions Module Pin Mnemonic Function CPU32 DSI/IFETCH DSI/IFETCH TPU ADC DSO/IPIPE DSO/IPIPE BKPT/DSCLK BKPT/DSCLK TPUCH[15:0] TPU Input T2CLK TCR2 Clock AN[6:0]/PADA[6:0] Analog Input 3.7.3 Reset Timing The RESET input must be asserted for a specified minimum period in order for reset to occur. External RESET assertion can be delayed internally for a period equal to the longest bus cycle time (or the bus monitor time-out period) in order to protect write cycles from being aborted by reset. While RESET is asserted, SIM pins are either in a disabled high-impedance state or are driven to their inactive states. 38 MC68334 MC68334TS/D REV. 1 When an external device asserts RESET for the proper period, reset control logic clocks the signal into an internal latch. The control logic drives the RESET pin low for an additional 512 CLKOUT cycles after it detects that the RESET signal is no longer being externally driven, to guarantee this length of reset to the entire system. If an internal source asserts a reset signal, the reset control logic asserts RESET for a minimum of 512 cycles. If the reset signal is still asserted at the end of 512 cycles, the control logic continues to assert RESET until the internal reset signal is negated. After 512 cycles have elapsed, the reset input pin goes to an inactive, high-impedance state for 10 cycles. At the end of this 10-cycle period, the reset input is tested. When the input is at logic level one, reset exception processing begins. If, however, the reset input is at logic level zero, the reset control logic drives the pin low for another 512 cycles. At the end of this period, the pin again goes to highimpedance state for ten cycles, then it is tested again. The process repeats until RESET is released. 3.7.4 Power-On Reset When the SIM clock synthesizer is used to generate the system clock, power-on reset involves special circumstances related to application of system and clock synthesizer power. Regardless of clock source, voltage must be applied to clock synthesizer power input pin VDDSYN in order for the MCU to operate. The following discussion assumes that VDDSYN is applied before and during reset. This minimizes crystal start-up time. When VDDSYN is applied at power-on, start-up time is affected by specific crystal parameters and by oscillator circuit design. VDD ramp-up time also affects pin state during reset. During power-on reset, an internal circuit in the SIM drives the internal IMB and external reset lines. The circuit releases the internal reset line as VDD ramps up to the minimum specified value, and SIM pins are initialized. As VDD reaches specified minimum value, the clock synthesizer VCO begins operation and clock frequency ramps up to specified limp mode frequency. The external RESET line remains asserted until the clock synthesizer PLL locks and 512 CLKOUT cycles elapse. The SIM clock synthesizer provides clock signals to the other MCU modules. After the clock is running and the internal reset signal is asserted for four clock cycles, these modules reset. VDD ramp time and VCO frequency ramp time determine how long these four cycles take. Worst case is approximately 15 milliseconds. During this period, module port pins may be in an indeterminate state. While input-only pins can be put in a known state by means of external pull-up resistors, external logic on input/output or output-only pins must condition the lines during this time. Active drivers require high-impedance buffers or isolation resistors to prevent conflict. 3.7.5 Use of Three State Control Pin Asserting the three-state control (TSC) input causes the MCU to put all output drivers in an inactive, high-impedance state. The signal must remain asserted for ten clock cycles in order for drivers to change state. There are certain constraints on use of TSC during power-on reset: When the internal clock synthesizer is used (MODCLK held high during reset), synthesizer ramp-up time affects how long the ten cycles take. Worst case is approximately 20 ms from TSC assertion. When an external clock signal is applied (MODCLK held low during reset), pins go to high-impedance state as soon after TSC assertion as ten clock pulses have been applied to the EXTAL pin. When TSC assertion takes effect, internal signals are forced to values that can cause inadvertent mode selection. Once the output drivers change state, the MCU must be powered down and restarted before normal operation can resume. MC68334 MC68334TS/D REV. 1 39 3.8 Interrupts Interrupt recognition and servicing involve complex interaction between the central processing unit, the system integration module, and a device or module requesting interrupt service. The CPU32 provides eight levels of interrupt priority. All interrupts with priorities less than seven can be masked by the interrupt priority (IP) field in status register. There are seven interrupt request signals (IRQ[7:1]). These signals are used internally on the IMB, and there are corresponding pins for external interrupt service requests. The CPU treats all interrupt requests as though they come from internal modules — external interrupt requests are treated as interrupt service requests from the SIM. Each of the interrupt request signals corresponds to an interrupt priority level. IRQ1 has the lowest priority and IRQ7 the highest. Interrupt recognition is determined by interrupt priority level and interrupt priority mask value. The interrupt priority mask consists of three bits in the CPU32 status register. Binary values %000 to %111 provide eight priority masks. Masks prevent an interrupt request of a priority less than or equal to the mask value from being recognized and processed. IRQ7, however, is always recognized, even if the mask value is %111. IRQ[7:1] are active-low level-sensitive inputs. The low on the pin must remain asserted until an interrupt acknowledge cycle corresponding to that level is detected. IRQ7 is transition-sensitive as well as level-sensitive: a level-7 interrupt is not detected unless a falling edge transition is detected on the IRQ7 line. This prevents redundant servicing and stack overflow. A nonmaskable interrupt is generated each time IRQ7 is asserted as well as each time the priority mask changes from%111 to a lower number while IRQ7 is asserted. Interrupt requests are sampled on consecutive falling edges of the system clock. Interrupt request input circuitry has hysteresis: to be valid, a request signal must be asserted for at least two consecutive clock periods. Valid requests do not cause immediate exception processing, but are left pending. Pending requests are processed at instruction boundaries or when exception processing of higher-priority exceptions is complete. The CPU32 does not latch the priority of a pending interrupt request. If an interrupt source of higher priority makes a service request while a lower priority request is pending, the higher priority request is serviced. If an interrupt request with a priority equal to or lower than the current IP mask value is made, the CPU32 does not recognize the occurrence of the request. If simultaneous interrupt requests of different priorities are made, and both have a priority greater than the mask value, the CPU32 recognizes the higher-level request. 3.8.1 Interrupt Acknowledge and Arbitration When the CPU32 detects one or more interrupt requests of a priority higher than the interrupt priority mask value, it places the interrupt request level on the address bus and initiates a CPU space read cycle. The request level serves two purposes: it is decoded by modules or external devices that have requested interrupt service, to determine whether the current interrupt acknowledge cycle pertains to them, and it is latched into the interrupt priority mask field in the CPU32 status register, to preclude further interrupts of lower priority during interrupt service. Modules or external devices that have requested interrupt service must decode the interrupt priority mask value placed on the address bus during the interrupt acknowledge cycle and respond if the priority of the service request corresponds to the mask value. However, before modules or external devices respond, interrupt arbitration takes place. Arbitration is performed by means of serial contention between values stored in individual module interrupt arbitration (IARB) fields. Each module that can make an interrupt service request, including the SIM, has an IARB field in its configuration register. IARB fields can be assigned values from %0000 to 40 MC68334 MC68334TS/D REV. 1 %1111. In order to implement an arbitration scheme, each module that can initiate an interrupt service request must be assigned a unique, non-zero IARB field value during system initialization. Arbitration priorities range from %0001 (lowest) to %1111 (highest) — if the CPU recognizes an interrupt service request from a source that has an IARB field value of %0000, a spurious interrupt exception is processed. WARNING Do not assign the same arbitration priority to more than one module. When two or more IARB fields have the same nonzero value, the CPU32 interprets multiple vector numbers at the same time, with unpredictable consequences. Because the EBI manages external interrupt requests, the SIM IARB value is used for arbitration between internal and external interrupt requests. The reset value of IARB for the SIM is %1111, and the reset IARB value for all other modules is %0000. Although arbitration is intended to deal with simultaneous requests of the same priority, it always takes place, even when a single source is requesting service. This is important for two reasons: the EBI does not transfer the interrupt acknowledge read cycle to the external bus unless the SIM wins contention, and failure to contend causes the interrupt acknowledge bus cycle to be terminated early, by a bus error. When arbitration is complete, the module with the highest arbitration priority must terminate the bus cycle. Internal modules place an interrupt vector number on the data bus and generate appropriate internal cycle termination signals. In the case of an external interrupt request, after the interrupt acknowledge cycle is transferred to the external bus, the appropriate external device must decode the mask value and respond with a vector number, then generate data and size acknowledge (DSACK) termination signals, or it must assert the autovector (AVEC) request signal. If the device does not respond in time, the EBI bus monitor asserts the bus error signal BERR, and a spurious interrupt exception is taken. Chip-select logic can also be used to generate internal AVEC or DSACK signals in response to interrupt requests from external devices. Chip-select address match logic functions only after the EBI transfers an interrupt acknowledge cycle to the external bus following IARB contention. If a module makes an interrupt request of a certain priority, and the appropriate chip-select registers are programmed to generate AVEC or DSACK signals in response to an interrupt acknowledge cycle for that priority level, chipselect logic does not respond to the interrupt acknowledge cycle, and the internal module supplies a vector number and generates internal cycle termination signals. For periodic timer interrupts, the PIRQ field in the periodic interrupt control register (PICR) determines PIT priority level. A PIRQ value of %000 means that PIT interrupts are inactive. By hardware convention, when the CPU32 receives simultaneous interrupt requests of the same level from more than one SIM source (including external devices), the periodic interrupt timer is given the highest priority, followed by the IRQ pins. Refer to 3.2.7 Periodic Interrupt Timer for more information. 3.8.2 Interrupt Processing Summary A summary of the interrupt processing sequence follows. When the sequence begins, a valid interrupt service request has been detected and is pending. A. The CPU finishes higher priority exception processing or reaches an instruction boundary. B. The processor state is stacked. The S bit in the status register is set, establishing supervisor access level, and bits T1 and T0 are cleared, disabling tracing. C. The interrupt acknowledge cycle begins: 1. FC[2:0] are driven to %111 (CPU space) encoding. 2. The address bus is driven as follows: ADDR[23:20] = %1111; ADDR[19:16] = %1111, which indicates that the cycle is an interrupt acknowledge CPU space cycle; ADDR[15:4] = %111111111111; ADDR[3:1] = the priority of the interrupt request being acknowledged; and ADDR0 = %1. MC68334 MC68334TS/D REV. 1 41 3. D. E. F. G. The request level is latched from the address bus into the interrupt priority mask field in the status or condition code register. Modules that have requested interrupt service decode the priority value in ADDR[3:1]. If request priority is the same as acknowledged priority, arbitration by IARB contention takes place. After arbitration, the interrupt acknowledge cycle is completed in one of the following ways: 1. When there is no contention (IARB = %0000), the spurious interrupt monitor asserts BERR, and the CPU generates the spurious interrupt vector number. 2. The dominant interrupt source supplies a vector number and DSACK signals appropriate to the access. The CPU acquires the vector number. 3. The AVEC signal is asserted (the signal can be asserted by the dominant interrupt source or the pin can be tied low), and the CPU generates an autovector number corresponding to interrupt priority. 4. The bus monitor asserts BERR and the CPU32 generates the spurious interrupt vector number. The vector number is converted to a vector address. The content of the vector address is loaded into the PC, and the processor transfers control to the exception handler routine. 3.9 Factory Test Block The test submodule supports scan-based testing of the various MCU modules. It is integrated into the SIM to support production testing. Test submodule registers are intended for Freescale use. Register names and addresses are provided to indicate that these addresses are occupied. SIMTR — System Integration Test Register $YFFA02 SIMTRE — System Integration Test Register (E Clock) $YFFA08 TSTMSRA — Master Shift Register A $YFFA30 TSTMSRB — Master Shift Register B $YFFA32 TSTSC — Test Module Shift Count $YFFA34 TSTRC — Test Module Repetition Count $YFFA36 CREG — Test Module Control Register $YFFA38 DREG — Test Module Distributed Register $YFFA3A 42 MC68334 MC68334TS/D REV. 1 4 Central Processor Unit Based on the powerful MC68020, the CPU32 processing module provides enhanced system performance and also uses the extensive software base for the Freescale M68000 family. 4.1 Overview The CPU32 is fully object code compatible with the M68000 Family, which excels at processing calculation-intensive algorithms and supporting high-level languages. The CPU32 supports all of the MC68010 and most of the MC68020 enhancements, such as virtual memory support, loop mode operation, instruction pipeline, and 32-bit mathematical operations. Powerful addressing modes provide compatibility with existing software programs and increase the efficiency of high-level language compilers. Special instructions, such as table lookup and interpolate and low-power stop, support the specific requirements of controller applications. Also included is the background debugging mode, an alternate operating mode that suspends normal operation and allows the CPU to accept debugging commands from the development system. Ease of programming is an important consideration in using a microcontroller. The CPU32 instruction set is optimized for high performance. The eight 32-bit general-purpose data registers readily support 8-bit (byte), 16-bit (word), and 32-bit (long word) operations. Ease of program checking and diagnosis is further enhanced by trace and trap capabilities at the instruction level. Use of high-level languages is increasing as controller applications become more complex and control programs become larger. High-level languages aid rapid development of software, with less error, and are readily portable. The CPU32 instruction set supports high-level languages. 4.2 Programming Model The CPU32 has sixteen 32-bit general registers, a 32-bit program counter, one 32-bit supervisor stack pointer, a 16-bit status register, two alternate function code registers, and a 32-bit vector base register. The programming model of the CPU32 consists of a user model and supervisor model, corresponding to the user and supervisor privilege levels. Some instructions available at the supervisor level are not available at the user level, allowing the supervisor to protect system resources from uncontrolled access. Bit S in the status register determines the privilege level. The user programming model remains unchanged from previous M68000 Family microprocessors. Application software written to run at the non-privileged user level migrates without modification to the CPU32 from any M68000 platform. The move from SR instruction, however, is privileged in the CPU32. It is not privileged in the M68000. MC68334 MC68334TS/D REV. 1 43 User Programming Model 31 16 15 8 7 0 D0 D1 D2 D3 Data Registers D4 D5 D6 D7 31 16 15 0 A0 A1 A2 A3 Address Registers A4 A5 A6 31 16 15 0 31 A7 (USP) User Stack Pointer PC Program Counter CCR Condition Code Register 0 7 0 Supervisor Programming Model Supplement 31 16 15 15 0 8 7 A7' (SSP) Supervisor Stack Pointer SR Status Register VBR Vector Base Register SFC Alternate Function DFC Code Registers 0 (CCR) 31 0 2 0 4.3 Status Register The status register contains the condition codes that reflect the results of a previous operation and can be used for conditional instruction execution in a program. The lower byte containing the condition codes is the only portion of the register available at the user privilege level; it is referenced as the condition code register (CCR) in user programs. At the supervisor privilege level, software can access the full status register, including the interrupt priority mask and additional control bits. 44 MC68334 MC68334TS/D REV. 1 SR — Status Register 15 14 13 12 11 T1 T0 S 0 0 0 1 0 0 10 9 8 IP 7 6 5 4 3 2 1 0 0 0 0 X N Z V C 0 0 0 U U U U U RESET: 0 1 1 1 System Byte T[1:0] — Trace Enable S — Supervisor/User State Bits [12:11] — Unimplemented IP[2:0] — Interrupt Priority Mask User Byte (Condition Code Register) Bits [7:5] — Unimplemented X — Extend N — Negative Z — Zero V — Overflow C — Carry 4.4 Data Types Six basic data types are supported: • Bits • Packed Binary Coded Decimal Digits • Byte Integers (8 bits) • Word Integers (16 bits) • Long-Word Integers (32 bits) • Quad-Word Integers (64 bits) 4.5 Addressing Modes Addressing in the CPU32 is register-oriented. Most instructions allow the results of the specified operation to be placed either in a register or directly in memory. This flexibility eliminates the need for extra instructions to store register contents in memory. The CPU32 supports seven basic addressing modes: • Register direct • Register indirect • Register indirect with index • Program counter indirect with displacement • Program counter indirect with index • Absolute • Immediate Included in the register indirect addressing modes are the capabilities to post-increment, predecrement, and offset. The program counter relative mode also has index and offset capabilities. In addition to these addressing modes, many instructions implicitly specify the use of the status register, stack pointer, or program counter. MC68334 MC68334TS/D REV. 1 45 4.6 Instruction Set Summary Table 23 Instruction Set Summary Instruction ABCD Syntax Dn, Dn – (An), – (An) Dn, 〈ea〉 〈ea〉, Dn 〈ea〉, An #〈data〉, 〈ea〉 #〈data〉, 〈ea〉 Dn, Dn – (An), – (An) 〈ea〉, Dn Dn, 〈ea〉 #〈data〉, 〈ea〉 #〈data〉, CCR #〈data〉, SR Operand Size 8 8 8, 16, 32 8, 16, 32 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 8 16 Dn, Dn #〈data〉, Dn 〈ea〉 8, 16, 32 8, 16, 32 16 Dn, Dn #〈data〉, Dn 〈ea〉 8, 16, 32 8, 16, 32 16 BGND 〈label〉 Dn, 〈ea〉 #〈data〉, 〈ea〉 Dn, 〈ea〉 #〈data〉, 〈ea〉 none 8, 16, 32 8, 32 8, 32 8, 32 8, 32 none BKPT #〈data〉 none BRA BSET CHK CHK2 〈label〉 Dn, 〈ea〉 #〈data〉, 〈ea〉 〈label〉 Dn, 〈ea〉 #〈data〉, 〈ea〉 〈ea〉, Dn 〈ea〉, Rn 8, 16, 32 8, 32 8, 32 8, 16, 32 8, 32 8, 32 16, 32 8, 16, 32 CLR CMP CMPA CMPI CMPM CMP2 〈ea〉 〈ea〉, Dn 〈ea〉, An #〈data〉, 〈ea〉 (An) +, (An) + 〈ea〉, Rn 8, 16, 32 8, 16, 32 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 ADD ADDA ADDI ADDQ ADDX AND ANDI ANDI to CCR ANDI to SR1 ASL ASR Bcc BCHG BCLR BSR BTST 46 Operation Source10 + Destination10+ X ⇒ Destination Source + Destination ⇒ Destination Source + Destination ⇒ Destination Immediate data + Destination ⇒ Destination Immediate data + Destination ⇒ Destination Source + Destination + X ⇒ Destination Source ∗ Destination ⇒ Destination Data ∗ Destination ⇒ Destination Source ∗ CCR ⇒ CCR Source ∗ SR ⇒ SR X/C 0 X/C If condition true, then PC + d ⇒ PC (〈bit number〉 of destination) ⇒ Z ⇒ bit of destination (〈bit number〉 of destination) ⇒ Z; 0 ⇒ bit of destination If background mode enabled, then enter background mode, else format/vector offset ⇒ – (SSP); PC ⇒ – (SSP); SR ⇒ – (SSP); (vector) ⇒ PC If breakpoint cycle acknowledged, then execute returned operation word, else trap as illegal instruction. PC + d ⇒ PC (〈bit number〉 of destination) ⇒ Z; 1 ⇒ bit of destination SP – 4 ⇒ SP; PC ⇒ (SP); PC + d ⇒ PC (〈bit number〉 of destination) ⇒ Z If Dn < 0 or Dn < (ea), then CHK exception If Rn < lower bound or Rn > upper bound, then CHK exception 0 ⇒ Destination (Destination – Source), CCR shows results (Destination – Source), CCR shows results (Destination – Data), CCR shows results (Destination – Source), CCR shows results Lower bound ≤ Rn ≤ Upper bound, CCR shows result MC68334 MC68334TS/D REV. 1 Table 23 Instruction Set Summary Instruction DBcc Syntax Dn, 〈label〉 DIVS/DIVU 〈ea〉, Dn DIVSL/DIVUL 〈ea〉, Dr: Dq 〈ea〉, Dq 〈ea〉, Dr : Dq Dn, 〈ea〉 #〈data〉, 〈ea〉 #〈data〉, CCR #〈data〉, SR EOR EORI EORI to CCR EORI to SR1 EXG EXT Operand Size 16 Operation If condition false, then Dn – 1 ⇒ PC; if Dn ≠ (– 1), then PC + d ⇒ PC 32/16 ⇒ 16: 16 Destination / Source ⇒ Destination (signed or unsigned) 64/32 ⇒ 32 : 32 Destination / Source ⇒ Destination (signed or unsigned) 32/32 ⇒ 32 32/32 ⇒ 32 : 32 8, 16, 32 Source ⊕ Destination ⇒ Destination 8, 16, 32 Data ⊕ Destination ⇒ Destination 8 Source ⊕ CCR ⇒ CCR 16 Source ⊕ SR ⇒ SR Rn ⇒ Rn Sign extended Destination ⇒ Destination Rn, Rn Dn Dn Dn none 32 8 ⇒ 16 16 ⇒ 32 8 ⇒ 32 none 〈ea〉 〈ea〉 〈ea〉, An An, #〈d〉 #〈data〉 none none 32 16, 32 none Dn, Dn #〈data〉, Dn 〈ea〉 8, 16, 32 8, 16, 32 16 Dn, Dn #〈data〉, Dn 〈ea〉 8, 16, 32 8, 16, 32 16 〈ea〉, 〈ea〉 〈ea〉, An USP, An An, USP CCR, 〈ea〉 8, 16, 32 16, 32 ⇒ 32 32 32 16 MOVE from SR1 〈ea〉, CCR SR, 〈ea〉 16 16 Source ⇒ CCR SR ⇒ Destination MOVE to SR1 〈εα〉, SR 16 Source ⇒ SR MOVE USP1 USP, An An, USP Rc, Rn Rn, Rc list, 〈ea〉 〈ea〉, list Dn, (d16, An) 32 32 32 32 16, 32 16, 32 ⇒ 32 16, 32 EXTB ILLEGAL JMP JSR LEA LINK LPSTOP1 LSL LSR MOVE MOVEA MOVEA1 MOVE from CCR MOVE to CCR MOVEC1 MOVEM MOVEP (d16, An), Dn MC68334 MC68334TS/D REV. 1 Sign extended Destination ⇒ Destination SSP – 2 ⇒ SSP; vector offset ⇒ (SSP); SSP – 4 ⇒ SSP; PC ⇒ (SSP); SSP – 2 ⇒ SSP; SR ⇒ (SSP); illegal instruction vector address ⇒ PC Destination ⇒ PC SP – 4 ⇒ SP; PC ⇒ (SP); destination ⇒ PC 〈ea〉 ⇒ An SP – 4 ⇒ SP, An ⇒ (SP); SP ⇒ An, SP + d ⇒ SP Data ⇒ SR; interrupt mask ⇒ EBI; STOP X/C 0 0 X/C Source ⇒ Destination Source ⇒ Destination USP ⇒ An An ⇒ USP CCR ⇒ Destination USP ⇒ An An ⇒ USP Rc ⇒ Rn Rn ⇒ Rc Listed registers ⇒ Destination Source ⇒ Listed registers Dn [31:24] ⇒ (An + d); Dn [23:16] ⇒ (An + d + 2); Dn [15:8] ⇒ (An + d + 4); Dn [7:0] ⇒ (An + d + 6) (An + d) ⇒ Dn [31:24]; (An + d + 2) ⇒ Dn [23:16]; (An + d + 4) ⇒ Dn [15:8]; (An + d + 6) ⇒ Dn [7:0] 47 Table 23 Instruction Set Summary Instruction MOVEQ MOVES1 MULS/MULU NBCD NEG NEGX NOP NOT OR ORI ORI to CCR ORI to SR1 PEA RESET1 ROL Syntax #〈data〉, Dn Rn, 〈ea〉 〈ea〉, Rn 〈ea〉, Dn 〈ea〉, Dl 〈ea〉, Dh:Dl 〈ea〉 Operand Size 8 ⇒ 32 8, 16, 32 Operation Immediate data ⇒ Destination Rn ⇒ Destination using DFC Source using SFC ⇒ Rn Source ∗ Destination ⇒ Destination (signed or unsigned) 〈ea〉 〈ea〉 none 〈ea〉 〈ea〉, Dn Dn, 〈ea〉 #〈data〉, 〈ea〉 #〈data〉, CCR #〈data〉, SR 16 ∗ 16 ⇒ 32 32 ∗ 32 ⇒ 32 32 ∗ 32 ⇒ 64 8 8 8, 16, 32 8, 16, 32 none 8, 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 16 16 〈ea〉 none 32 none Dn, Dn #〈data〉, Dn 〈ea〉 8, 16, 32 8, 16, 32 16 0 – Destination10 – X ⇒ Destination 0 – Destination ⇒ Destination 0 – Destination – X ⇒ Destination PC + 2 ⇒ PC Destination ⇒ Destination Source; Destination ⇒ Destination Data; Destination ⇒ Destination Source; CCR ⇒ SR Source; SR ⇒ SR SP – 4 ⇒ SP; 〈ea〉 ⇒ SP Assert RESET line C ROR Dn, Dn #〈data〉, Dn 〈ea〉 8, 16, 32 8, 16, 32 16 C ROXL Dn, Dn #〈data〉, Dn 〈ea〉 8, 16, 32 8, 16, 32 16 C ROXR Dn, Dn #〈data〉, Dn 〈ea〉 X 8, 16, 32 8, 16, 32 16 X RTD RTE1 #〈d〉 none 16 none RTR none none RTS SBCD none Dn, Dn – (An), – (An) 〈ea〉 none 8 8 8 #〈data〉 16 〈ea〉, Dn Dn, 〈ea〉 8, 16, 32 Scc STOP1 SUB 48 C (SP) ⇒ PC; SP + 4 + d ⇒ SP (SP) ⇒ SR; SP + 2 ⇒ SP; (SP) ⇒ PC; SP + 4 ⇒ SP; restore stack according to format (SP) ⇒ CCR; SP + 2 ⇒ SP; (SP) ⇒ PC; SP + 4 ⇒ SP (SP) ⇒ PC; SP + 4 ⇒ SP Destination10 – Source10 – X ⇒ Destination If condition true, then destination bits are set to one; else, destination bits are cleared to zero Data ⇒ SR; STOP Destination – Source ⇒ Destination MC68334 MC68334TS/D REV. 1 Table 23 Instruction Set Summary Instruction SUBA SUBI SUBQ SUBX SWAP Syntax 〈ea〉, An #〈data〉, 〈ea〉 #〈data〉, 〈ea〉 Dn, Dn – (An), – (An) Dn Operand Size 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 8, 16, 32 16 Operation Destination – Source ⇒ Destination Destination – Data ⇒ Destination Destination – Data ⇒ Destination Destination – Source – X ⇒ Destination MSW TBLS/TBLU 〈ea〉, Dn Dym : Dyn, Dn 8, 16, 32 TBLSN/TBLUN 〈ea〉, Dn Dym : Dyn, Dn 8, 16, 32 TRAP #〈data〉 none TRAPcc none #〈data〉 none 〈ea〉 An none 16, 32 none 8, 16, 32 32 TRAPV TST UNLK LSW Dyn – Dym ⇒ Temp (Temp ∗ Dn [7:0]) ⇒ Temp (Dym ∗ 256) + Temp ⇒ Dn Dyn – Dym ⇒ Temp (Temp ∗ Dn [7:0]) / 256 ⇒ Temp Dym + Temp ⇒ Dn SSP – 2 ⇒ SSP; format/vector offset ⇒ (SSP); SSP – 4 ⇒ SSP; PC ⇒ (SSP); SR ⇒ (SSP); vector address ⇒ PC If cc true, then TRAP exception If V set, then overflow TRAP exception Source – 0, to set condition codes An ⇒ SP; (SP) ⇒ An, SP + 4 ⇒ SP NOTE: 1. Privileged instruction 4.7 Background Debugging Mode The background debugger on the CPU32 is implemented in CPU microcode. The background debugging commands are summarized below. MC68334 MC68334TS/D REV. 1 49 Table 24 Background Debugging Command Summary Command Read D/A Register Write D/A Register Read System Register Write System Register Read Memory Location Write Memory Location Dump Memory Block Fill Memory Block Resume Execution Patch User Code Reset Peripherals No Operation 50 Mnemonic RDREG/RAREG Description Read the selected address or data register and return the results through the serial interface. WDREG/WAREG The data operand is written to the specified address or data register. RSREG The specified system control register is read. All registers that can be read in supervisor mode can be read in background mode. WSREG The operand data is written into the specified system control register. READ Read the sized data at the memory location specified by the long-word address. The source function code register (SFC) determines the address space accessed. WRITE Write the operand data to the memory location specified by the long-word address. The destination function code (DFC) register determines the address space accessed. DUMP Used in conjunction with the READ command to dump large blocks of memory. An initial READ is executed to set up the starting address of the block and retrieve the first result. Subsequent operands are retrieved with the DUMP command. FILL Used in conjunction with the WRITE command to fill large blocks of memory. Initially, a WRITE is executed to set up the starting address of the block and supply the first operand. The FILL command writes subsequent operands. GO The pipe is flushed and refilled before resuming instruction execution at the current PC. CALL Current program counter is stacked at the location of the current stack pointer. Instruction execution begins at user patch code. RST Asserts RESET for 512 clock cycles. The CPU is not reset by this command. Synonymous with the CPU RESET instruction. NOP NOP performs no operation and can be used as a null command. MC68334 MC68334TS/D REV. 1 5 Time Processor Unit The time processor unit (TPU) is an intelligent, semi-autonomous microcontroller designed for timing control. The TPU operates simultaneously with the CPU; it processes ROM instructions, schedules tasks, performs input and output, and accesses shared data without CPU intervention. Consequently, setup and service time for each timer event are minimized. The figure below is a simplified block diagram of the TPU. HOST INTERFACE CONTROL SCHEDULER SERVICE REQUESTS TIMER CHANNELS CHANNEL 0 IMB CHANNEL SYSTEM CONFIGURATION TCR1 CHANNEL 1 TCR2 T2CLK DEVELOPMENT SUPPORT AND TEST PINS MICROENGINE CHANNEL CONTROL PARAMETER RAM DATA DATA CONTROL STORE CONTROL AND DATA EXECUTION UNIT CHANNEL 15 TPU BLOCK Figure 11 TPU Block Diagram 5.1 Overview The TPU can be viewed as a special-purpose microcomputer that performs a programmable series of two operations, match and capture. Each occurrence of either operation is called an event. A programmed series of events is called a function. TPU functions replace software functions that would require host CPU interrupt service. Two sets of mask-programmed functions are currently available. Refer to 5.6 Time Functions for more information. 5.2 Programmer's Model The TPU control register address map occupies 512 bytes. The “Access” column in the TPU address map below indicates which registers are accessible only at the supervisor privilege level and which can be assigned to either the supervisor or user privilege level, according to the value of the SUPV bit in the TPUMCR. MC68334 MC68334TS/D REV. 1 51 Table 25 TPU Address Map Access Address 15 8 7 0 S $YFFE00 TPU MODULE CONFIGURATION REGISTER (TPUMCR) S $YFFE02 TEST CONFIGURATION REGISTER (TCR) S $YFFE04 DEVELOPMENT SUPPORT CONTROL REGISTER (DSCR) S $YFFE06 DEVELOPMENT SUPPORT STATUS REGISTER (DSSR) S $YFFE08 TPU INTERRUPT CONFIGURATION REGISTER (TICR) S $YFFE0A CHANNEL INTERRUPT ENABLE REGISTER (CIER) S $YFFE0C CHANNEL FUNCTION SELECTION REGISTER 0 (CFSR0) S $YFFE0E CHANNEL FUNCTION SELECTION REGISTER 1 (CFSR1) S $YFFE10 CHANNEL FUNCTION SELECTION REGISTER 2 (CFSR2) S $YFFE12 CHANNEL FUNCTION SELECTION REGISTER 3 (CFSR3) S/U $YFFE14 HOST SEQUENCE REGISTER 0 (HSQR0) S/U $YFFE16 HOST SEQUENCE REGISTER 1 (HSQR1) S/U $YFFE18 HOST SERVICE REQUEST REGISTER 0 (HSRR0) S/U $YFFE1A HOST SERVICE REQUEST REGISTER 1 (HSRR1) S $YFFE1C CHANNEL PRIORITY REGISTER 0 (CPR0) S $YFFE1E CHANNEL PRIORITY REGISTER 1 (CPR1) S $YFFE20 CHANNEL INTERRUPT STATUS REGISTER (CISR) S $YFFE22 LINK REGISTER (LR) S $YFFE24 SERVICE GRANT LATCH REGISTER (SGLR) S $YFFE26 DECODED CHANNEL NUMBER REGISTER (DCNR) Y = M111, where M represents the logic state of the MM bit in the SIMCR. 5.3 TPU Components The TPU module consists of two 16-bit time bases, sixteen independent timer channels, a task scheduler, a microengine, and a host interface. In addition, a dual-port parameter RAM is used to pass parameters between the module and the host CPU. 5.3.1 Time Bases Two 16-bit counters provide reference time bases for all output compare and input capture events. Prescalers for both time bases are controlled by the host CPU via bit fields in the TPU module configuration register (TPUMCR). Timer count registers TCR1 and TCR2 provide access to current counter values. TCR1 and TCR2 can be read/write accessed in microcode, but are not directly available to the host CPU. The TCR1 clock is derived from the system clock. The TCR2 clock can be derived from the system clock or from an external clock input via the T2CLK pin. 5.3.2 Timer Channels The TPU has 16 independent channels, each connected to an MCU pin. The channels have identical hardware. Each channel consists of an event register and pin control logic. The event register contains a 16-bit capture register, a 16-bit compare/match register, and a 16-bit greater-than-or-equal-to comparator. The direction of each pin, either output or input, is determined by the TPU microengine. Each channel can either use the same time base for match and capture, or can use one time base for match and the other for capture. 52 MC68334 MC68334TS/D REV. 1 5.3.3 Scheduler When a service request is received, the scheduler determines which TPU channel is serviced by the microengine. A channel can request service for one of four reasons: for host service, for a link to another channel, for a match event, or for a capture event. The host system assigns each active channel one of three priorities: high, middle, or low. When multiple service requests are received simultaneously, a priority-scheduling mechanism grants service based on channel number and assigned priority. 5.3.4 Microengine The microengine is composed of a control store and an execution unit. Control-store ROM holds the microcode for each factory-masked time function. When assigned to a channel by the scheduler, the execution unit executes microcode for a function assigned to that channel by the host CPU. Microcode can also be executed from the TPURAM module instead of the control store. The TPURAM module allows emulation and development of custom TPU microcode without the generation of a microcode ROM mask. Refer to 5.5 Emulation Support for more information. 5.3.5 Host Interface Host interface registers allow communication between the host CPU and the TPU, both before and during execution of a time function. The registers are accessible from the IMB through the TPU bus interface unit. 5.3.6 Parameter RAM Parameter RAM occupies 256 bytes at the top of the system address map. Channel parameters are organized as 128 16-bit words. Although all parameter word locations in RAM can be accessed by all channels, only 100 are normally used: channels 0 to 13 use six parameter words, while channels 14 and 15 each use eight parameter words. The parameter RAM address map shows how parameter words are organized in memory. The host CPU specifies function parameters by writing the appropriate RAM address. The TPU reads the RAM to determine channel operation. The TPU can also store information to be read by the CPU in RAM. Detailed descriptions of the parameters required by each time function are beyond the scope of this technical summary. Refer to the TPU Reference Manual (TPURM/AD) for more information. For pre-programmed functions, one of the parameter words associated with each channel contains three channel control fields. These fields perform the following functions: PSC — Forces the output level of the pin. PAC — For input capture, PAC specifies the edge transition to be detected. For output comparison, PAC specifies the logic level to be output when a match occurs. TBS — Specifies channel direction (input or output) and assigns a time base to the input capture and output compare functions of the channel. MC68334 MC68334TS/D REV. 1 53 Table 26 TPU Parameter RAM Address Map Channel Number 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Base Address $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## $YFFFF## 0 00 10 20 30 40 50 60 70 80 90 A0 B0 C0 D0 E0 F0 1 02 12 22 32 42 52 62 72 82 92 A2 B2 C2 D2 E2 F2 2 04 14 24 34 44 54 64 74 84 94 A4 B4 C4 D4 E4 F4 Parameter Address 3 4 06 08 16 18 26 28 36 38 46 48 56 58 66 68 76 78 86 88 96 98 A6 A8 B6 B8 C6 C8 D6 D8 E6 E8 F6 F8 5 0A 1A 2A 3A 4A 5A 6A 7A 8A 9A AA BA CA DA EA FA 6 — — — — — — — — — — — — — — EC FC 7 — — — — — — — — — — — — — — EE FE — = Not Implemented Y = M111, where M represents the logic state of the MM bit in the SIMCR. 5.4 TPU Operation All TPU functions are related to one of the two 16-bit free-running timebases. Functions are synthesized by combining sequences of match events and capture events. Because the primitives are implemented in hardware, the TPU can determine precisely when a match or capture event occurs, and respond rapidly. An event register for each channel provides for simultaneity of match/capture event occurrences on all channels. When a match or input capture event requiring service occurs, the affected channel generates a service request to the scheduler. The scheduler determines the priority of the request and assigns the channel to the microengine at the first available time. The microengine performs the function defined by the content of the control store or emulation RAM, using parameters from the parameter RAM. 5.4.1 Event Timing Match and capture events are handled by independent channel hardware. This provides an event accuracy of one time-base clock period, regardless of the number of channels that are active. An event normally causes a channel to request service. However, before an event can be serviced, any pending previous requests must be serviced. The time needed to respond to and service an event is determined by the number of channels requesting service, the relative priorities of the channels requesting service, and the microcode execution time of the active functions. Worst-case event service time (latency) determines TPU performance in a given application. Latency can be closely estimated — see Freescale TPU Reference Manual (TPURM/AD) for more information. 5.4.2 Channel Orthogonality Most timer systems are limited by the fixed number of functions assigned to each pin. All TPU channels contain identical hardware and are functionally equivalent in operation, so that any channel can be configured to perform any time function. Any function can operate on the calling channel, and, under program control, on another channel determined by the program or by a parameter. The user controls the combination of time functions. 54 MC68334 MC68334TS/D REV. 1 5.4.3 Interchannel Communication The autonomy of the TPU is enhanced by the ability of a channel to affect the operation of one or more other channels without CPU intervention. Interchannel communication can be accomplished by issuing a link service request to another channel, by controlling another channel directly, or by accessing the parameter RAM of another channel. 5.4.4 Programmable Channel Service Priority The TPU provides a programmable service priority level to each channel. Three priority levels are available. When more than one channel of a given priority requests service at the same time, arbitration is accomplished according to channel number. To prevent a single high-priority channel from permanently blocking other functions, other service requests of the same priority are performed in channel order after the lowest-numbered, highest-priority channel is serviced. 5.4.5 Coherency For data to be coherent, all available portions of it must be identical in age, or must be logically related. As an example, consider a 32-bit counter value that is read and written as two 16-bit words. The 32-bit value is read-coherent only if both 16-bit portions are updated at the same time, and write-coherent only if both portions take effect at the same time. Parameter RAM hardware supports coherent access of two adjacent 16-bit parameters. The host CPU must use a long-word operation to guarantee coherency. 5.5 Emulation Support Although factory-programmed time functions can perform a wide variety of control tasks, they may not be ideal for all applications. The TPU provides emulation capability that allows the user to develop new time functions. Emulation mode is entered by setting the EMU bit in the TPUMCR. In emulation mode, an auxiliary bus connection is made between TPURAM and the TPU module, and access to TPURAM via the intermodule bus is disabled. A 9-bit address bus, a 32-bit data bus, and control lines transfer information between the modules. To ensure exact emulation, RAM module access timing remains consistent with access timing of the TPU ROM control store. To support changing TPU application requirements, Freescale has established a TPU function library. The function library is a collection of TPU functions written for easy assembly in combination with each other or with custom functions. Refer to Freescale Programming Note TPUPN00/D,Using the TPU Function Library and TPU Emulation Mode for information about developing custom functions and accessing the TPU function library. Refer to the TPU Reference Manual (TPURM/AD) for more information about specific functions. 5.6 Time Functions The following paragraphs describe factory-programmed time functions implemented in the TPU microcode ROM. A complete description of the functions is beyond the scope of this summary. Refer to the TPU Reference Manual (TPURM/AD) for additional information. 5.6.1 Table Stepper Motor (TSM) The TSM function provides for acceleration and deceleration control of a stepper motor with a programmable number of step rates up to 58. TSM uses a table in parameter RAM, rather than an algorithm, to define the stepper motor acceleration profile, allowing the user to fully define the profile. In addition, a slew rate parameter allows fine control of the terminal running speed of the motor independent of the acceleration table. The CPU need only write a desired position, and the TPU accelerates, slews, and decelerates the motor to the required position. Full and half step support is provided for two-phase motors. In addition, a slew rate parameter allows fine control of the terminal running speed of the motor independent of the acceleration table. MC68334 MC68334TS/D REV. 1 55 5.6.2 Input Capture/Transition Counter (ITC) Any channel of the TPU can capture the value of a specified TCR or any specified location in parameter RAM upon the occurrence of each transition or specified number of transitions, and then generate an interrupt request to notify the bus master. The times of the most recent two transitions are maintained in parameter RAM. A channel can perform input captures continually, or a channel can detect a single transition or specified number of transitions, ceasing channel activity until reinitialization. After each transition or specified number of transitions, the channel can generate a link to other channels. 5.6.3 Queued Output Match (QOM) QOM can generate single or multiple output match events from a table of offsets in parameter RAM. Loop modes allow complex pulse trains to be generated once, a specified number of times, or continuously. The function can be triggered by a link from another TPU channel. In addition, the reference time for the sequence of matches can be obtained from another channel. QOM can generate pulse-width modulated waveforms, including waveforms with high times of 0% or 100%. QOM also allows a TPU channel to be used as a discrete output pin. 5.6.4 Programmable Time Accumulator (PTA) PTA accumulates a 32-bit sum of the total high time, low time, or period of an input signal over a programmable number of periods or pulses. The accumulation can start on a rising or falling edge. After the specified number of periods or pulses, the PTA generates an interrupt request and optionally generates links to other channels. From 1 to 255 period measurements can be made and summed with the previous measurement(s) before the TPU interrupts the CPU, providing instantaneous or average frequency measurement capability, and the latest complete accumulation (over the programmed number of periods). 5.6.5 Multichannel Pulse-Width Modulation (MCPWM) MCPWM generates pulse-width modulated outputs with full 0% to 100% duty cycle range independent of other TPU activity. This capability requires two TPU channels plus an external gate for one PWM channel. (A simple one-channel PWM capability is supported by the QOM function.) Multiple PWMs generated by MCPWM have two types of high time alignment: edge aligned and center aligned. Edge aligned mode uses n + 1 TPU channels for n PWMs; center aligned mode uses 2n + 1 channels. Center aligned mode allows a user defined ‘dead time’ to be specified so that two PWMs can be used to drive an H-bridge without destructive current spikes. This feature is important for motor control applications. 5.6.6 Fast Quadrature Decode (FQD) FQD is a position feedback function for motor control. It decodes the two signals from a slotted encoder to provide the CPU with a 16-bit free running position counter. FQD incorporates a “speed switch” which disables one of the channels at high speed, allowing faster signals to be decoded. A time stamp is provided on every counter update to allow position interpolation and better velocity determination at low speed or when low resolution encoders are used. The third index channel provided by some encoders is handled by the ITC function. 5.6.7 Universal Asynchronous Receiver/Transmitter (UART) The UART function uses one or two TPU channels to provide asynchronous communications. Data word length is programmable from 1 to 14 bits. The function supports detection or generation of even, odd, and no parity. Baud rate is freely programmable and can be higher than 100 Kbaud. Eight bidirectional UART channels running in excess of 9600 baud could be implemented on the TPU. 56 MC68334 MC68334TS/D REV. 1 5.6.8 Brushless Motor Commutation (COMM) This function generates the phase commutation signals for a variety of brushless motors, including three-phase brushless direct current. It derives the commutation state directly from the position decoded in FQD, thus eliminating the need for hall effect sensors. The state sequence is implemented as a user-configurable state machine, thus providing a flexible approach with other general applications. A CPU offset parameter is provided to allow all the switching angles to be advanced or retarded on the fly by the CPU. This feature is useful for torque maintenance at high speeds. 5.6.9 Frequency Measurement (FQM) FQM counts the number of input pulses to a TPU channel during a user-defined window period. The function has single shot and continuous modes. No pulses are lost between sample windows in continuous mode. The user selects whether to detect pulses on the rising or falling edge. This function is intended for high speed measurement; measurement of slow pulses with noise rejection can be made with PTA. 5.6.10 Hall Effect Decode (HALLD) This function decodes the sensor signals from a brushless motor, along with a direction input from the CPU, into a state number. The function supports two- or three-sensor decoding. The decoded state number is written into a COMM channel, which outputs the required commutation drive signals. In addition to brushless motor applications, the function can have more general applications, such as decoding “option” switches. 5.7 TPU Registers The TPU memory map contains three groups of registers: System Configuration Registers Channel Control and Status Registers Development Support and Test Verification Registers 5.7.1 System Configuration Registers TPUMCR — TPU Module Configuration Register 15 14 STOP 13 12 TCR1P 11 TCR2P $YFFE00 10 9 8 7 6 5 4 EMU T2CG STF SUPV PSCK 0 0 0 0 0 1 0 0 0 3 2 1 0 0 0 IARB RESET: 0 0 0 0 0 0 0 STOP — Stop Bit 0 = TPU operating normally 1 = Internal clocks shut down TCR1P — Timer Count Register 1 Prescaler Control TCR1 is clocked from the output of a prescaler. The prescaler's input is the internal TPU system clock divided by either 4 or 32, depending on the value of the PSCK bit. The prescaler divides this input by 1, 2, 4, or 8. Channels using TCR1 have the capability to resolve down to the TPU system clock divided by 4. MC68334 MC68334TS/D REV. 1 57 ÷2 SYSTEM CLOCK ÷4 DIV2 CLOCK DIV4 CLOCK PSCK MUX ÷ 32 DIV32 CLOCK TCR1 PRESCALER 00 ÷ 1 01 ÷ 2 10 ÷ 4 11 ÷ 8 CSEL MUX 0 15 TCR1 0 – TCR1 PRESCALER 1 – DIV2 0 – DIV32 CLOCK 1 – DIV4 CLOCK TPU PRE BLOCK 1 Figure 12 Prescaler Control 1 TCR1 Prescaler Divide By 1 2 4 8 00 01 10 11 PSCK = 0 Number of Rate at Clocks 16 MHz 32 2 ms 64 4 ms 128 8 ms 256 16 ms PSCK = 1 Number of Rate at Clocks 16 MHz 4 250 ns 8 500 ns 16 1 ms 32 2 ms TCR2P — Timer Count Register 2 Prescaler Control TCR2 is clocked from the output of a prescaler. If T2CG = 0, the input to the TCR2 prescaler is the external TCR2 clock source. If T2CG = 1, the input is the TPU system clock divided by eight. The TCR2P field specifies the value of the prescaler: 1, 2, 4, or 8. Channels using TCR2 have the capability to resolve down to the TPU system clock divided by 8. The following table is a summary of prescaler output. TCR2 Prescaler Divide By Internal Clock Divided By External Clock Divided By 00 1 8 1 01 2 16 2 10 4 32 4 11 8 64 8 EMU — Emulation Control In emulation mode, the TPU executes microinstructions from MCU TPURAM exclusively. Access to the TPURAM module through the IMB by a host is blocked, and the TPURAM module is dedicated for use by the TPU. After reset, this bit can be written only once. 0 = TPU and TPURAM not in emulation mode 1 = TPU and TPURAM in emulation mode T2CG — TCR2 Clock/Gate Control When the T2CG bit is set, the external TCR2 pin functions as a gate of the DIV8 clock (the TPU system clock divided by 8). In this case, when the external TCR2 pin is low, the DIV8 clock is blocked, preventing it from incrementing TCR2. When the external TCR2 pin is high, TCR2 is incremented at the frequency of the DIV8 clock. When T2CG is cleared, an external clock from the TCR2 pin, which has been synchronized and fed through a digital filter, increments TCR2. 0 = TCR2 pin used as clock source for TCR2 1 = TCR2 pin used as gate of DIV8 clock for TCR2 58 MC68334 MC68334TS/D REV. 1 0–A 1–B T2C FILTER BIT DIGITAL FILTER 0–A 1–B T2CG CONTROL BIT A A MUX T2CLK PIN TCR2 PRESCALER PROGRAMMABLE B DIGITAL FILTER SYNCHRONIZER 0 15 00 ÷ 1 01 ÷ 2 10 ÷ 4 11 ÷ 8 MUX B INT CLK ÷ 8 TCR2 TPU PRE BLOCK 2 Figure 13 Prescaler Control 2 STF — Stop Flag 0 = TPU operating 1 = TPU stopped (STOP bit has been asserted) SUPV — Supervisor Data Space 0 = Assignable registers are unrestricted (FC2 is ignored) 1 = Assignable registers are restricted (FC2 is decoded) PSCK — Prescaler Clock 0 = System clock/32 is input to TCR1 prescaler 1 = System clock/4 is input to TCR1 prescaler IARB — Interrupt Arbitration Identification Number The IARB field is used to arbitrate between simultaneous interrupt requests of the same priority. Each module that can generate interrupt requests must be assigned a unique, nonzero IARB field value. Refer to 3.8 Interrupts for more information. TICR — TPU Interrupt Configuration Register 15 14 13 12 11 10 NOT USED 9 $YFFE08 8 7 6 CIRL 5 4 CIBV 3 2 1 0 NOT USED RESET: 0 0 0 0 0 0 0 CIRL — Channel Interrupt Request Level The interrupt request level for all channels is specified by this 3-bit encoded field. Level seven for this field indicates a nonmaskable interrupt; level zero indicates that all channel interrupts are disabled. CIBV — Channel Interrupt Base Vector The TPU is assigned 16 unique interrupt vector numbers, one vector number for each channel. The CIBV field specifies the most significant nibble of all 16 TPU channel interrupt vector numbers. The lower nibble of the TPU interrupt vector number is determined by the channel number on which the interrupt occurs. MC68334 MC68334TS/D REV. 1 59 5.7.2 Channel Control Registers CIER — Channel Interrupt Enable Register $YFFE0A 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CH 15 CH 14 CH 13 CH 12 CH 11 CH 10 CH 9 CH 8 CH 7 CH 6 CH 5 CH 4 CH 3 CH 2 CH 1 CH 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 RESET: 0 0 CH[15:0] — Channel Interrupt Enable/Disable 0 = Channel interrupts disabled 1 = Channel interrupts enabled CISR — Channel Interrupt Status Register $YFFE20 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CH 15 CH 14 CH 13 CH 12 CH 11 CH 10 CH 9 CH 8 CH 7 CH 6 CH 5 CH 4 CH 3 CH 2 CH 1 CH 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 RESET: 0 0 CH[15:0] — Channel Interrupt Status Bit 0 = Channel interrupt not asserted 1 = Channel interrupt asserted CFSR0 — Channel Function Select Register 0 15 14 13 12 11 CHANNEL15 10 9 $YFFE0C 8 7 CHANNEL14 6 5 4 3 CHANNEL13 2 1 0 CHANNEL12 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CFSR1 — Channel Function Select Register 1 15 14 13 12 11 CHANNEL11 10 9 0 0 $YFFE0E 8 7 CHANNEL10 6 5 4 3 CHANNEL9 2 1 0 CHANNEL8 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CFSR2 — Channel Function Select Register 2 15 14 13 12 11 CHANNEL7 10 9 0 0 $YFFE10 8 7 CHANNEL6 6 5 4 3 CHANNEL5 2 1 0 CHANNEL4 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CFSR3 — Channel Function Select Register 3 15 14 13 12 11 CHANNEL3 10 9 0 0 $YFFE12 8 7 CHANNEL2 6 5 4 3 CHANNEL1 2 1 0 CHANNEL0 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CHANNEL[15:0] — Encoded Time Function for each Channel Encoded 4-bit fields in the channel function select registers specify one of 16 time functions to be executed on the corresponding channel. 60 MC68334 MC68334TS/D REV. 1 HSQR0 — Host Sequence Register 0 15 14 13 CH 15 12 11 CH 14 10 $YFFE14 9 CH 13 8 7 CH 12 6 5 CH 11 4 3 CH 10 2 1 CH 9 0 CH 8 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 HSQR1 — Host Sequence Register 1 15 14 13 CH 7 12 11 10 CH 6 0 0 $YFFE16 9 CH 5 8 7 CH 4 6 5 CH 3 4 3 CH 2 2 1 CH 1 0 CH 0 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CH[15:0] — Encoded Host Sequence The host sequence field selects the mode of operation for the time function selected on a given channel. The meaning of the host sequence bits depends on the time function specified. HSRR0 — Host Service Request Register 0 15 14 13 CH 15 12 11 CH 14 10 $YFFE18 9 CH 13 8 7 CH 12 6 5 CH 11 4 3 CH 10 2 1 CH 9 0 CH 8 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 HSRR1 — Host Service Request Register 1 15 14 13 CH 7 12 11 CH 6 10 0 $YFFE1A 9 CH 5 0 8 7 CH 4 6 5 CH 3 4 3 CH 2 2 1 CH 1 0 CH 0 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CH[15:0] — Encoded Type of Host Service The host service request field selects the type of host service request for the time function selected on a given channel. The meaning of the host service request bits depends on the time function specified. A host service request field cleared to %00 signals the host that service is completed by the microengine on that channel. The host can request service on a channel by writing the corresponding host service request field to one of three nonzero states. The CPU should monitor the host service request register until the TPU clears the service request to %00 before the CPU changes any parameters or issues a new service request to the channel. CPR0 — Channel Priority Register 0 15 14 13 CH 15 12 $YFFE1C 11 CH 14 10 9 CH 13 8 7 CH 12 6 5 CH 11 4 3 CH 10 2 1 CH 9 0 CH 8 RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CPR1 — Channel Priority Register 1 15 14 13 CH 7 12 11 CH 6 0 0 $YFFE1E 10 9 CH 5 8 7 CH 4 6 5 CH 3 4 3 CH 2 2 1 CH 1 0 CH 0 RESET: 0 0 0 MC68334 MC68334TS/D REV. 1 0 0 0 0 0 0 0 0 0 0 0 0 0 61 CH[15:0] — Encoded One of Three Channel Priority Levels CHX[1:0] 00 01 10 11 Service Disabled Low Middle High Guaranteed Time Slots — 4 out of 7 2 out of 7 1 out of 7 5.7.3 Development Support and Test Registers These registers are used for custom microcode development or for factory test. Describing the use of the registers is beyond the scope of this technical summary. Register names and addresses are given for reference only. Refer to the TPU Reference Manual (TPURM/AD) for more information. DSCR — Development Support Control Register $YFFE04 DSSR — Development Support Status Register $YFFE06 LR — Link Register $YFFE22 SGLR — Service Grant Latch Register $YFFE24 DCNR — Decoded Channel Number Register $YFFE26 TCR — Test Configuration Register $YFFE02 62 MC68334 MC68334TS/D REV. 1 6 Analog-to-Digital Converter Module The analog-to-digital converter (ADC) is a unipolar, successive-approximation converter with eight modes of operation. It has selectable 8- or 10-bit resolution. Accuracy is ±1 count (1 LSB) in 8-bit mode and ±4 counts (2 LSB) in 10-bit mode. Monotonicity is guaranteed in both modes. The ADC can perform an 8-bit single conversion (4-clock sample) in 10 microseconds and a 10-bit single conversion in 11 microseconds. The ADC consists of an analog and a digital subsystem. A block diagram of the converter appears on the following page. 6.1 Analog Subsystem The analog front end consists of a multiplexer, a buffer amplifier, a resistor-capacitor array, and a highgain comparator. The multiplexer selects one of eight internal or seven external signal sources for conversion. The resistor capacitor digital-to-analog converter (RC DAC) array performs two functions: it acts as a sample/hold circuit, and it provides the digital-to-analog comparison output necessary for successive approximation conversion. The comparator indicates whether each successive output of the RC DAC array is higher or lower than the sampled input. 6.2 Digital Control Subsystem The digital control section includes conversion sequence control logic, channel and reference select logic, a successive approximation register, eight result registers, a port data register, and control/status registers. It controls the multiplexer and the output of the RC DAC array during the sample and conversion periods, stores the results of comparison in the successive-approximation register, and transfers the result to a result register. The ADC bus interface unit (ABIU) contains logic necessary to interface the ADC to the intermodule bus. The ADC is designed to act as a slave device on the bus. The interface must respond with appropriate bus cycle termination signals and supply appropriate interface timing to the other submodules. MC68334 MC68334TS/D REV. 1 63 VDDA VSSA SUPPLY RC DAC ARRAY AND COMPARATOR SAR MODE AND TIMING CONTROL RESULT 0 RESULT 1 RESULT 2 RESULT 3 VRH VRL ANALOG MUX AND SAMPLE BUFFER AMP RESERVED RESERVED RESERVED RESERVED V RH V RL (V RH–VRL )/2 RESERVED REFERENCE AN6/PADA6 AN5/PADA5 AN4/PADA4 AN3/PADA3 AN2/PADA2 AN1/PADA1 AN0/PADA0 INTERNAL CONNECTIONS PORT ADA DATA REGISTER RESULT 4 RESULT 5 RESULT 6 RESULT 7 CLK SELECT/ PRESCALE ADC BUS INTERFACE UNIT INTERMODULE BUS (IMB) ADC BLOCK 7CHAN Figure 14 Analog-to-Digital Converter Block Diagram 6.3 ADC Address Map The ADC control register address map occupies 64 bytes. The “Access” column in the ADC address map below indicates which registers are accessible only at the supervisor privilege level and which can be assigned to either the supervisor or user privilege level, according to the value of the SUPV bit in the ADCMCR. 64 MC68334 MC68334TS/D REV. 1 Table 27 ADC Module Address Map Access S S S S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U S/U Address $YFF700 $YFF702 $YFF704 $YFF706 $YFF708 $YFF70A $YFF70C $YFF70E $YFF710 $YFF712 $YFF714 $YFF716 $YFF718 $YFF71A $YFF71C $YFF71E $YFF720 $YFF722 $YFF724 $YFF726 $YFF728 $YFF72A $YFF72C $YFF72E $YFF730 $YFF732 $YFF734 $YFF736 $YFF738 $YFF73A $YFF73C $YFF73E 15 8 7 ADC MODULE CONFIGURATION REGISTER (ADCMCR) ADC FACTORY TEST REGISTER (ADTEST) (RESERVED) PORT ADA DATA (PORTADA) (RESERVED) ADC CONTROL 0 (ADCTL0) ADC CONTROL 1 (ADCTL1) ADC STATUS (ADSTAT) RIGHT-JUSTIFIED UNSIGNED RESULT 0 (RJURR0) RIGHT-JUSTIFIED UNSIGNED RESULT 1 (RJURR1) RIGHT-JUSTIFIED UNSIGNED RESULT 2 (RJURR2) RIGHT-JUSTIFIED UNSIGNED RESULT 3 (RJURR3) RIGHT-JUSTIFIED UNSIGNED RESULT 4 (RJURR4) RIGHT-JUSTIFIED UNSIGNED RESULT 5 (RJURR5) RIGHT-JUSTIFIED UNSIGNED RESULT 6 (RJURR6) RIGHT-JUSTIFIED UNSIGNED RESULT 7 (RJURR7) LEFT-JUSTIFIED SIGNED RESULT 0 (LJSRR0) LEFT-JUSTIFIED SIGNED RESULT 1 (LJSRR1) LEFT-JUSTIFIED SIGNED RESULT 2 (LJSRR2) LEFT-JUSTIFIED SIGNED RESULT 3 (LJSRR3) LEFT-JUSTIFIED SIGNED RESULT 4 (LJSRR4) LEFT-JUSTIFIED SIGNED RESULT 5 (LJSRR5) LEFT-JUSTIFIED SIGNED RESULT 6 (LJSRR6) LEFT-JUSTIFIED SIGNED RESULT 7 (LJSRR7) LEFT-JUSTIFIED UNSIGNED RESULT 0 (LJURR0) LEFT-JUSTIFIED UNSIGNED RESULT 1 (LJURR1) LEFT-JUSTIFIED UNSIGNED RESULT 2 (LJURR2) LEFT-JUSTIFIED UNSIGNED RESULT 3 (LJURR3) LEFT-JUSTIFIED UNSIGNED RESULT 4 (LJURR4) LEFT-JUSTIFIED UNSIGNED RESULT 5 (LJURR5) LEFT-JUSTIFIED UNSIGNED RESULT 6 (LJURR6) LEFT-JUSTIFIED UNSIGNED RESULT 7 (LJURR7) 0 Y = M111, where M is the logic state of the MM bit in the SIMCR MC68334 MC68334TS/D REV. 1 65 6.4 ADC Registers ADCMCR — ADC Module Configuration Register 15 14 STOP 13 12 11 FRZ 10 9 $YFF700 8 NOT USED 7 6 5 4 SUPV 3 2 1 0 NOT USED RESET: 1 0 0 0 The ADCMCR is used to initialize the ADC. STOP — STOP Mode 0 = Normal operation 1 = Low-power operation STOP places the ADC in low-power state by disabling the ADC clock and powering down the analog circuitry. Setting STOP aborts any conversion in progress. STOP is set to logic level one at reset, and may be cleared to logic level zero by the CPU. Clearing STOP enables normal ADC operation. However, because analog circuitry bias current has been turned off, there is a period of recovery before output stabilization. FRZ[1:0] — Freeze 1 The FRZ field is used to determine ADC response to assertion of the FREEZE signal. The following table shows possible responses. FRZ 00 01 10 11 Response Ignore FREEZE Reserved Finish conversion, then freeze Freeze immediately SUPV — Supervisor/Unrestricted 0 = Unrestricted access 1 = Supervisor access SUPV defines access to assignable ADC registers. ADTEST — ADC Test Register $YFF702 ADTEST is used during factory test of the ADC. PORTADA — Port ADA Data Register 15 14 13 12 11 NOT USED 10 $YFF706 9 8 7 6 5 4 3 2 1 0 PORT ADA DATA RESET: Reflects state of the input pins Port ADA is an input port that shares pins with the A/D converter inputs. The port ADA data register resides in the lower half of the PDR. Bit 7 always returns zero when read. PDR[6:0] — Port ADA Data A read of PDR[6:0] will return the logic level of the port A pins. If the input is outside the defined voltage range, the result of the read will be indeterminate. Use of a port A pin for digital input does not preclude use as an analog input. 66 MC68334 MC68334TS/D REV. 1 ADCTL0 — A/D Control Register 0 15 14 13 12 11 $YFF70A 10 9 NOT USED 8 7 6 RES10 5 4 3 STS 2 1 0 1 1 PRS RESET: 0 0 0 0 0 0 ADCTL0 is used to select ADC clock source and to set up prescaling. Writes to it have immediate effect. RES10 — 10-Bit Resolution 0 = 8-bit resolution 1 = 10-bit resolution Conversion results are appropriately aligned in result registers to reflect conversion status. STS[1:0] — Sample Time Select Total conversion time depends on initial sample time, transfer time, final sample time, and resolution time. Initial sample time is fixed at two clocks. Transfer time is fixed at two clocks. Resolution time is fixed at ten ADC clock cycles for an 8-bit conversion and twelve ADC clock cycles for a 10-bit conversion. Final sample time depends on the STS field, as shown below. STS[1:0] 00 01 10 11 Sample Time 2 A/D Clock Periods 4 A/D Clock Periods 8 A/D Clock Periods 16 A/D Clock Periods PRS[4:0] — Prescaler Rate Selection Field ADC clock is generated from system clock using a modulo counter and a divide-by-two circuit. The binary value of this field is the counter modulus. System clock is divided by the PRS value plus one, then sent to the divide-by-two circuit, as shown in the following table. Maximum ADC clock rate is 2 MHz. Reset value of PRS is a divisor value of eight, resulting in a nominal 2-MHz ADC clock. PRS[4:0] 00000 00001 00010 ... 11101 11110 11111 MC68334 MC68334TS/D REV. 1 Divisor Value 4 4 6 ... 60 62 64 67 ADCTL1 — A/D Control Register 1 15 14 13 12 11 NOT USED $YFF70C 10 9 8 7 6 5 4 3 2 1 0 SCAN MULT S8CM CD CC CB CA 0 0 0 0 0 0 0 RESET: ADCTL1 is used to initiate an A/D conversion and to select conversion modes and a conversion channel. It can be written or read at any time. A write to ADCTL1 initiates a conversion sequence. If a conversion sequence is already in progress, a write to ADCTL1 aborts it and resets the SCF and CCF flags in the ADC status register. SCAN — Scan Mode Selection Bit 0 = Single conversion sequence 1 = Continuous conversion Length of conversion sequence(s) is determined by S8CM. MULT — Multichannel Conversion Bit 0 = Conversion sequence(s) run on single channel (channel selected via [CD:CA]) 1 = Sequential conversion of a block of four or eight channels (block selected via [CD:CA]) Length of conversion sequence(s) is determined by S8CM. S8CM — Select Eight-Conversion Sequence Mode 0 = Four-conversion sequence 1 = Eight-conversion sequence This bit determines the number of conversions in a conversion sequence. CD:CA — Channel Selection Field The bits in this field are used to select an input or block of inputs for A/D conversion. The following table summarizes the operation of S8CM and CD:CA when MULT is cleared (single channel mode). Number of conversions per channel is determined by SCAN. 68 MC68334 MC68334TS/D REV. 1 S8CM 0 0 0 0 0 0 0 0 0 0 0 0 0 CD 0 0 0 0 0 0 0 0 1 1 1 1 1 CC 0 0 0 0 1 1 1 1 0 0 0 0 1 CB 0 0 1 1 0 0 1 1 0 0 1 1 0 CA 0 1 0 1 0 1 0 1 0 1 0 1 0 Input AN0 AN1 AN2 AN3 AN4 AN5 AN6 AN7* Reserved Reserved Reserved Reserved VRH Result Register RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 RSLT0 – RSLT3 0 1 1 0 1 VRL RSLT0 – RSLT3 0 1 1 1 0 (VRH – VRL) / 2 RSLT0 – RSLT3 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 Test/Reserved AN0 AN1 AN2 AN3 AN4 AN5 AN6 AN7* Reserved Reserved Reserved Reserved VRH RSLT0 – RSLT3 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 RSLT0 – RSLT7 1 1 1 0 1 VRL RSLT0 – RSLT7 1 1 1 1 0 (VRH – VRL) / 2 RSLT0 – RSLT7 1 1 1 1 1 Test/Reserved RSLT0 – RSLT7 * Since the ADC in the MCU has only seven external analog inputs, AN7 is connected to VSSA. MC68334 MC68334TS/D REV. 1 69 The following table summarizes the operation of S8CM and CD:CA when MULT is set (multichannel mode). Number of conversions per channel is determined by SCAN. Channel numbers are given in order of conversion. S8CM 0 CD 0 CC 0 CB X CA X 0 0 1 X X 0 1 0 X X 0 1 1 X X 1 0 X X X 1 1 X X X Input AN0 AN1 AN2 AN3 AN4 AN5 AN6 AN7* Reserved Reserved Reserved Reserved VRH Result Register RSLT0 RSLT1 RSLT2 RSLT3 RSLT0 RSLT1 RSLT2 RSLT3 RSLT0 RSLT1 RSLT2 RSLT3 RSLT0 VRL RSLT1 (VRH – VRL) / 2 RSLT2 Test/Reserved AN0 AN1 AN2 AN3 AN4 AN5 AN6 AN7* Reserved Reserved Reserved Reserved VRH RSLT3 RSLT0 RSLT1 RSLT2 RSLT3 RSLT4 RSLT5 RSLT6 RSLT7 RSLT0 RSLT1 RSLT2 RSLT3 RSLT4 VRL RSLT5 (VRH – VRL) / 2 RSLT6 Test/Reserved RSLT7 * Since the ADC in the MCU has only seven external analog inputs, AN7 is connected to VSSA. 70 MC68334 MC68334TS/D REV. 1 ADSTAT — ADC Status Register 15 SCF 14 13 12 11 $YFF70E 10 NOT USED 9 8 7 6 5 4 CCTR 3 2 1 0 0 0 0 0 CCF RESET: 0 0 0 0 0 0 0 0 ADSTAT contains information related to the status of a conversion sequence. SCF — Sequence Complete Flag 0 = Sequence not complete 1 = Sequence complete SCF is set at the end of the conversion sequence when SCAN is cleared, and at the end of the first conversion sequence when SCAN is set. SCF is cleared when ADCTL1 is written and a new conversion sequence begins. CCTR[2:0] — Conversion Counter Field This field reflects the contents of the conversion counter pointer in either four or eight count conversion sequence. The value corresponds to the number of the next result register to be written, and thus indicates which channel is being converted. CCF[7:0] — Conversion Complete Field Each bit in this field corresponds to an A/D result register (CCF7 to RSLT7, etc.). A bit is set when conversion for the corresponding channel is complete, and remains set until the result register is read. RSLT[7:0] — A/D Result Registers $YFF710–$YFF73E The result registers store data after conversion is complete. Each register can be read from three different addresses in the register block. Data format depends on the address from which the result register is read. RJURR — Unsigned Right-Justified Format $YFF710–$YFF71F Conversion result is unsigned right-justified data. Bits [9:0] are used for 10-bit resolution, bits [7:0] are used for 8-bit resolution (bits [9:8] are zero). Bits [15:10] always return zero when read. LJSRR — Signed Left-Justified Format $YFF720–$YFF72F Conversion result is signed left-justified data. Bits [15:6] are used for 10-bit resolution, bits [15:8] are used for 8-bit resolution (bits [7:6] are zero). Although the ADC is unipolar, it is assumed that the zero point is halfway between low and high reference when this format is used. For positive input, bit 15 = 0, for negative input, bit 15 = 1. Bits [5:0] always return zero when read. LJURR — Unsigned Left-Justified Format $YFF730–$YFF73F Conversion result is unsigned left-justified data. Bits [15:6] are used for 10-bit resolution, bits [15:8] are used for 8-bit resolution (bits [7:6] are zero). Bits [5:0] always return zero when read. MC68334 MC68334TS/D REV. 1 71 7 Standby RAM with TPU Emulation The TPURAM module contains a 1-Kbyte array of fast (two bus cycle) static RAM, which is especially useful for system stacks and variable storage. Alternately, it can be used by the TPU as emulation RAM for new timer algorithms. 7.1 Overview The 1-Kbyte TPURAM array occupies the top 1024 bytes of a 2-Kbyte block (addresses $400 to $7FF when the ADDR11 bit in TRAMBAR = 0; addresses $0C00 to $0FFF when the ADDR11 bit in TRAMBAR = 1). The block can be mapped to any 2-Kbyte boundary in the address map, but must not overlap the module control registers (overlap makes the registers inaccessible). Data can be read or written in bytes, word, or long words. TPURAM responds to both program and data space accesses. Data can be read or written in bytes, word, or long words. The TPURAM is powered by VDD in normal operation. During power-down, the TPURAM contents are maintained by power on standby voltage pin VSTBY. Power switching between sources is automatic. Access to the TPURAM array is controlled by the RASP field in TRAMMCR. This field can be encoded so that TPURAM responds to both program and data space accesses. This allows code to be executed from TPURAM, and permits the use of program counter relative addressing mode for operand fetches from the array. An address map of the TPURAM control registers follows. All TPURAM control registers are located in supervisor data space. Table 28 TPURAM Control Register Address Map Access S S S Address $YFFB00 $YFFB02 $YFFB04 $YFFB06– $YFFB3F 15 8 7 TPURAM MODULE CONFIGURATION REGISTER (TRAMMCR) TPURAM TEST REGISTER (TRAMTST) TPURAM BASE ADDRESS REGISTER (TRAMBAR) NOT USED 0 Y = M111, where M is the logic state of the MM bit in the SIMCR. 7.2 TPURAM Register Block There are three TPURAM control registers: the TPURAM module configuration register (TRAMMCR), the TPURAM test register (TRAMTST), and the TPURAM array base address registers (TRAMBAR). There is an 8-byte minimum register block size for the module. Unimplemented register addresses are read as zeros, and writes have no effect. 7.3 TPURAM Registers TRAMMCR — TPURAM Module Configuration Register 15 14 13 12 11 10 9 8 STOP 0 0 0 0 0 0 RASP 0 0 0 0 0 0 1 $YFFB00 7 6 5 4 3 2 1 0 NOT USED RESET: 0 72 MC68334 MC68334TS/D REV. 1 STOP — Stop Control 0 = TPURAM array operates normally. 1 = TPURAM array enters low-power stop mode. This bit controls whether the TPURAM array is in stop mode or normal operation. Reset state is zero, for normal operation. In stop mode, the array retains its contents, but cannot be read or written by the CPU. RASP — RAM Array Space Field 0 = TPURAM array is placed in unrestricted space 1 = TPURAM array is placed in supervisor space TRAMTST — TPURAM Test Register $YFFB02 TRAMTST is used for factory testing of the TPURAM module. TRAMBAR — TPURAM Base Address and Status Register $YFFB04 15 14 13 12 11 10 9 8 7 6 5 4 3 ADDR 23 ADDR 22 ADDR 21 ADDR 20 ADDR 19 ADDR 18 ADDR 17 ADDR 16 ADDR 15 ADDR 14 ADDR 13 ADDR 12 ADDR 11 0 0 0 0 0 0 0 0 0 0 0 2 1 NOT USED 0 RAMD S RESET: 0 0 0 ADDR[23:11] — RAM Array Base Address This field specifies ADDR[23:11] of the TPURAM array base address when the array is enabled. ADDR11 determines the 2-Kbyte boundary that the block of addresses containing the array is mapped to. The array occupies only the upper 1024 bytes of the 2-Kbyte block of addresses. When ADDR11 bit is set, valid array addresses range from $0C00 to%0FFFF; when the ADDR11 bit is cleared, valid array addresses range from $0400 to $07FF. RAMDS — RAM Array Disable 0 = TPURAM array is enabled 1 = TPURAM array is disabled The TPURAM array is disabled by internal logic after a master reset. Writing a valid base address to the TPURAM array base address field (bits [15:3]) automatically clears RAMDS, enabling the TPURAM array. 7.4 TPURAM Operation There are six TPURAM operating modes, as follows: • The TPURAM module is in normal mode when powered by VDD. The array can be accessed by byte, word, or long word. A byte or aligned word (high-order byte is at an even address) access only takes one bus cycle or two system clocks. A long word or misaligned word access requires two bus cycles. • Standby mode is intended to preserve TPURAM contents when VDD is removed. TPURAM contents are maintained by VSTBY. Circuitry within the TPURAM module switches to the higher of VDD or VSTBY with no loss of data. When TPURAM is powered by VSTBY, access to the array is not guaranteed. • Reset mode allows the CPU to complete the current bus cycle before resetting. When a synchronous reset occurs while a byte or word TPURAM access is in progress, the access will be completed. If reset occurs during the first word access of a long-word operation, only the first word access will be completed. If reset occurs during the second word access of a long word operation, the entire access will be completed. Data being read from or written to the RAM may be corrupted by asynchronous reset. MC68334 MC68334TS/D REV. 1 73 • Test mode functions in conjunction with the SIM test functions. Test mode is used during factory test of the MCU. • Writing the STOP bit of TRAMMCR causes the TPURAM module to enter stop mode. The TPURAM array is disabled (which allows external logic to decode TPURAM addresses, if necessary), but all data is retained. If VDD falls below VSTBY during stop mode, internal circuitry switches to VSTBY, as in standby mode. Stop mode is exited by clearing the STOP bit. • The TPURAM array may be used to emulate the microcode ROM in the TPU module. This provides a means of developing custom TPU code. The TPU selects TPU emulation mode. While in TPU emulation mode, the access timing of the TPURAM module matches the timing of the TPU microinstruction ROM to ensure accurate emulation. Normal accesses via the IMB are inhibited and the control registers have no effect, allowing external RAM to emulate the TPURAM at the same addresses. 8 Summary of Changes This is a partial revision. Most of the publication remains the same, but the following changes were made to improve it. Typographical errors that do not affect content are not annotated. 74 Page 2 Ordering Information revised to reflect new quantities, TPU mask options. Page 7 Address map revised to reflect TPURAM array mapping. Pages 11-42 Expanded and revised SIM section. Added new information to 3.3 System Clock, 3.5 Chip Selects, 3.7 Resets, and 3.8 Interrupts. Page 72-74 Revised Standby RAM with TPU Emulation section to include details of array mapping to upper half of 2-Kbyte address block. MC68334 MC68334TS/D REV. 1 MC68334 MC68334TS/D REV. 1 75 How to Reach Us: Home Page: www.freescale.com E-mail: support@freescale.com RoHS-compliant and/or Pb- free versions of Freescale products have the functionality and electrical characteristics of their non-RoHS-compliant and/or non-Pb- free counterparts. For further information, see http://www.freescale.com or contact your Freescale sales representative. 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