C8051F060-GQ

C8051F060/1/2/3/4/5/6/7 8K ISP FLASH MCU Family Analog Peripherals - Two 16-Bit SAR ADCs • 16-bit resolution • ±0.75 LSB INL, guaranteed no missing codes • Programmable throughput up to 1 Msps • Operate as two single-ended or one differential con• - - • verter Direct memory access; data stored in RAM without software overhead Data-dependent windowed interrupt generator 10-bit SAR ADC (C8051F060/1/2/3) • • • Programmable throughput up to 200 ksps 8 external inputs, single-ended or differential Built-in temperature sensor • Can synchronize outputs to timers for jitter-free waveform generation Two 12-bit DACs (C8051F060/1/2/3) Three Analog Comparators • Programmable hysteresis/response time - Voltage Reference - Precision VDD Monitor/Brown-Out Detector On-Chip JTAG Debug & Boundary Scan - On-chip debug circuitry facilitates full-speed, non- intrusive in-circuit/in-system debugging Provides breakpoints, single-stepping, watchpoints, stack monitor; inspect/modify memory and registers Superior performance to emulation systems using ICE-chips, target pods, and sockets IEEE1149.1 compliant boundary scan Complete development kit Rev. 1.3 10/22 High Speed 8051 C Core - Pipelined instruction architecture; executes 70% of instruction set in 1 or 2 system clocks - Up to 25 MIPS throughput with 25 MHz clock - Flexible Interrupt sources Memory - 4352 Bytes internal data RAM (4 k + 256) - 64 kB (C8051F060/1/2/3/4/5), 32 kB (C8051F066/7) - Flash; In-system programmable in 512-byte sectors External 64 kB data memory interface with multiplexed and non-multiplexed modes (C8051F060/2/ 4/6) Digital Peripherals - 59 general purpose I/O pins (C8051F060/2/4/6) - 24 general purpose I/O pins (C8051F061/3/5/7) - Bosch Controller Area Network (CAN 2.0B - C8051F060/1/2/3) Hardware SMBus™ (I2C™ Compatible), SPI™, and two UART serial ports available concurrently Programmable 16-bit counter/timer array with 6 capture/compare modules 5 general purpose 16-bit counter/timers Dedicated watchdog timer; bi-directional reset pin Clock Sources - Internal calibrated precision oscillator: 24.5 MHz - External oscillator: Crystal, RC, C, or clock Supply Voltage .......................... 2.7 to 3.6 V - Multiple power saving sleep and shutdown modes 100-Pin and 64-Pin TQFP Packages Available Temperature Range: -40 to +85 °C Copyright © 2022 by Silicon Laboratories C8051F060/1/2/3/4/5/6/7 C8051F060/1/2/3/4/5/6/7 2 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Table of Contents 1. System Overview.................................................................................................... 19 1.1. CIP-51™ Microcontroller Core.......................................................................... 25 1.1.1. Fully 8051 Compatible.............................................................................. 25 1.1.2. Improved Throughput ............................................................................... 25 1.1.3. Additional Features .................................................................................. 26 1.2. On-Chip Memory............................................................................................... 27 1.3. JTAG Debug and Boundary Scan..................................................................... 28 1.4. Programmable Digital I/O and Crossbar ........................................................... 29 1.5. Programmable Counter Array ........................................................................... 30 1.6. Controller Area Network.................................................................................... 31 1.7. Serial Ports ....................................................................................................... 32 1.8. 16-Bit Analog to Digital Converters................................................................... 33 1.9. 10-Bit Analog to Digital Converter..................................................................... 34 1.10.12-bit Digital to Analog Converters................................................................... 35 1.11.Analog Comparators......................................................................................... 36 2. Absolute Maximum Ratings .................................................................................. 37 3. Global DC Electrical Characteristics .................................................................... 38 4. Pinout and Package Definitions............................................................................ 39 5. 16-Bit ADCs (ADC0 and ADC1) ............................................................................. 51 5.1. Single-Ended or Differential Operation ............................................................. 52 5.1.1. Pseudo-Differential Inputs ........................................................................ 52 5.2. Voltage Reference ............................................................................................ 53 5.3. ADC Modes of Operation.................................................................................. 54 5.3.1. Starting a Conversion............................................................................... 54 5.3.2. Tracking Modes........................................................................................ 54 5.3.3. Settling Time Requirements ..................................................................... 56 5.4. Calibration......................................................................................................... 66 5.5. ADC0 Programmable Window Detector ........................................................... 69 6. Direct Memory Access Interface (DMA0) ............................................................. 75 6.1. Writing to the Instruction Buffer......................................................................... 75 6.2. DMA0 Instruction Format .................................................................................. 76 6.3. XRAM Addressing and Setup ........................................................................... 76 6.4. Instruction Execution in Mode 0........................................................................ 77 6.5. Instruction Execution in Mode 1........................................................................ 78 6.6. Interrupt Sources .............................................................................................. 79 6.7. Data Buffer Overflow Warnings and Errors....................................................... 79 7. 10-Bit ADC (ADC2, C8051F060/1/2/3).................................................................... 87 7.1. Analog Multiplexer ............................................................................................ 88 7.2. Modes of Operation .......................................................................................... 89 7.2.1. Starting a Conversion............................................................................... 89 7.2.2. Tracking Modes........................................................................................ 90 7.2.3. Settling Time Requirements ..................................................................... 91 Rev. 1.3 3 C8051F060/1/2/3/4/5/6/7 7.3. Programmable Window Detector ...................................................................... 97 7.3.1. Window Detector In Single-Ended Mode ................................................. 99 7.3.2. Window Detector In Differential Mode.................................................... 100 8. DACs, 12-Bit Voltage Mode (DAC0 and DAC1, C8051F060/1/2/3) .................... 103 8.1. DAC Output Scheduling.................................................................................. 104 8.1.1. Update Output On-Demand ................................................................... 104 8.1.2. Update Output Based on Timer Overflow .............................................. 104 8.2. DAC Output Scaling/Justification .................................................................... 104 9. Voltage Reference 2 (C8051F060/2) .................................................................... 111 10. Voltage Reference 2 (C8051F061/3) ................................................................... 113 11. Voltage Reference 2 (C8051F064/5/6/7) .............................................................. 115 12. Comparators ......................................................................................................... 117 12.1.Comparator Inputs.......................................................................................... 119 13. CIP-51 Microcontroller ......................................................................................... 123 13.1.Instruction Set................................................................................................. 125 13.1.1.Instruction and CPU Timing ................................................................... 125 13.1.2.MOVX Instruction and Program Memory ............................................... 125 13.2.Memory Organization ..................................................................................... 130 13.2.1.Program Memory ................................................................................... 130 13.2.2.Data Memory.......................................................................................... 131 13.2.3.General Purpose Registers.................................................................... 131 13.2.4.Bit Addressable Locations...................................................................... 131 13.2.5.Stack ..................................................................................................... 131 13.2.6.Special Function Registers .................................................................... 132 13.2.6.1.SFR Paging ................................................................................... 132 13.2.6.2.Interrupts and SFR Paging ............................................................ 132 13.2.6.3.SFR Page Stack Example ............................................................. 134 13.2.7.Register Descriptions ............................................................................. 148 13.3.Interrupt Handler............................................................................................. 151 13.3.1.MCU Interrupt Sources and Vectors ...................................................... 151 13.3.2.External Interrupts.................................................................................. 151 13.3.3.Interrupt Priorities................................................................................... 153 13.3.4.Interrupt Latency .................................................................................... 153 13.3.5.Interrupt Register Descriptions............................................................... 154 13.4.Power Management Modes............................................................................ 160 13.4.1.Idle Mode ............................................................................................... 160 13.4.2.Stop Mode.............................................................................................. 161 14. Reset Sources....................................................................................................... 163 14.1.Power-on Reset.............................................................................................. 164 14.2.Power-fail Reset ............................................................................................. 164 14.3.External Reset ................................................................................................ 164 14.4.Missing Clock Detector Reset ........................................................................ 165 14.5.Comparator0 Reset ........................................................................................ 165 14.6.External CNVSTR2 Pin Reset ........................................................................ 165 14.7.Watchdog Timer Reset................................................................................... 165 4 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 14.7.1.Enable/Reset WDT ................................................................................ 166 14.7.2.Disable WDT .......................................................................................... 166 14.7.3.Disable WDT Lockout ............................................................................ 166 14.7.4.Setting WDT Interval .............................................................................. 166 15. Oscillators ............................................................................................................. 171 15.1.Programmable Internal Oscillator ................................................................... 171 15.2.External Oscillator Drive Circuit...................................................................... 173 15.3.System Clock Selection.................................................................................. 173 15.4.External Crystal Example ............................................................................... 175 15.5.External RC Example ..................................................................................... 175 15.6.External Capacitor Example ........................................................................... 175 16. Flash Memory ....................................................................................................... 177 16.1.Programming The Flash Memory ................................................................... 177 16.2.Non-volatile Data Storage .............................................................................. 178 16.3.Security Options ............................................................................................. 179 16.3.1.Summary of Flash Security Options....................................................... 183 17. External Data Memory Interface and On-Chip XRAM........................................ 187 17.1.Accessing XRAM............................................................................................ 187 17.1.1.16-Bit MOVX Example ........................................................................... 187 17.1.2.8-Bit MOVX Example ............................................................................. 187 17.2.Configuring the External Memory Interface .................................................... 188 17.3.Port Selection and Configuration.................................................................... 188 17.4.Multiplexed and Non-multiplexed Selection.................................................... 190 17.4.1.Multiplexed Configuration....................................................................... 190 17.4.2.Non-multiplexed Configuration............................................................... 191 17.5.Memory Mode Selection................................................................................. 192 17.5.1.Internal XRAM Only ............................................................................... 192 17.5.2.Split Mode without Bank Select.............................................................. 192 17.5.3.Split Mode with Bank Select................................................................... 193 17.5.4.External Only.......................................................................................... 193 17.6.Timing .......................................................................................................... 194 17.6.1.Non-multiplexed Mode ........................................................................... 196 17.6.1.1.16-bit MOVX: EMI0CF[4:2] = ‘101’, ‘110’, or ‘111’......................... 196 17.6.1.2.8-bit MOVX without Bank Select: EMI0CF[4:2] = ‘101’ or ‘111’. .... 197 17.6.1.3.8-bit MOVX with Bank Select: EMI0CF[4:2] = ‘110’....................... 198 17.6.2.Multiplexed Mode ................................................................................... 199 17.6.2.1.16-bit MOVX: EMI0CF[4:2] = ‘001’, ‘010’, or ‘011’......................... 199 17.6.2.2.8-bit MOVX without Bank Select: EMI0CF[4:2] = ‘001’ or ‘011’. .... 200 17.6.2.3.8-bit MOVX with Bank Select: EMI0CF[4:2] = ‘010’....................... 201 18. Port Input/Output.................................................................................................. 203 18.1.Ports 0 through 3 and the Priority Crossbar Decoder..................................... 205 18.1.1.Crossbar Pin Assignment and Allocation ............................................... 205 18.1.2.Configuring the Output Modes of the Port Pins...................................... 206 18.1.3.Configuring Port Pins as Digital Inputs................................................... 207 18.1.4.Weak Pull-ups ........................................................................................ 207 Rev. 1.3 5 C8051F060/1/2/3/4/5/6/7 18.1.5.Configuring Port 1 and 2 pins as Analog Inputs..................................... 207 18.1.6.Crossbar Pin Assignment Example........................................................ 208 18.2.Ports 4 through 7 (C8051F060/2/4/6 only) ..................................................... 219 18.2.1.Configuring Ports which are not Pinned Out .......................................... 219 18.2.2.Configuring the Output Modes of the Port Pins...................................... 219 18.2.3.Configuring Port Pins as Digital Inputs................................................... 219 18.2.4.Weak Pull-ups ........................................................................................ 219 18.2.5.External Memory Interface ..................................................................... 220 19. Controller Area Network (CAN0, C8051F060/1/2/3) ........................................... 225 19.1.Bosch CAN Controller Operation.................................................................... 227 19.2.CAN Registers................................................................................................ 228 19.2.1.CAN Controller Protocol Registers......................................................... 228 19.2.2.Message Object Interface Registers ...................................................... 228 19.2.3.Message Handler Registers................................................................... 228 19.2.4.CIP-51 MCU Special Function Registers ............................................... 229 19.2.5.Using CAN0ADR, CAN0DATH, and CANDATL To Access CAN Registers 229 19.2.6.CAN0ADR Autoincrement Feature ........................................................ 229 20. System Management BUS / I2C BUS (SMBUS0)................................................ 235 20.1.Supporting Documents ................................................................................... 236 20.2.SMBus Protocol.............................................................................................. 236 20.2.1.Arbitration............................................................................................... 237 20.2.2.Clock Low Extension.............................................................................. 237 20.2.3.SCL Low Timeout................................................................................... 237 20.2.4.SCL High (SMBus Free) Timeout .......................................................... 237 20.3.SMBus Transfer Modes.................................................................................. 238 20.3.1.Master Transmitter Mode ....................................................................... 238 20.3.2.Master Receiver Mode ........................................................................... 238 20.3.3.Slave Transmitter Mode ......................................................................... 239 20.3.4.Slave Receiver Mode ............................................................................. 239 20.4.SMBus Special Function Registers ................................................................ 241 20.4.1.Control Register ..................................................................................... 241 20.4.2.Clock Rate Register ............................................................................... 244 20.4.3.Data Register ......................................................................................... 245 20.4.4.Address Register.................................................................................... 245 20.4.5.Status Register....................................................................................... 246 21. Enhanced Serial Peripheral Interface (SPI0)...................................................... 251 21.1.Signal Descriptions......................................................................................... 252 21.1.1.Master Out, Slave In (MOSI).................................................................. 252 21.1.2.Master In, Slave Out (MISO).................................................................. 252 21.1.3.Serial Clock (SCK) ................................................................................. 252 21.1.4.Slave Select (NSS) ................................................................................ 252 21.2.SPI0 Master Mode Operation ......................................................................... 253 21.3.SPI0 Slave Mode Operation ........................................................................... 255 21.4.SPI0 Interrupt Sources ................................................................................... 255 6 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 21.5.Serial Clock Timing......................................................................................... 256 21.6.SPI Special Function Registers ...................................................................... 258 22. UART0.................................................................................................................... 265 22.1.UART0 Operational Modes ............................................................................ 266 22.1.1.Mode 0: Synchronous Mode .................................................................. 266 22.1.2.Mode 1: 8-Bit UART, Variable Baud Rate.............................................. 267 22.1.3.Mode 2: 9-Bit UART, Fixed Baud Rate .................................................. 269 22.1.4.Mode 3: 9-Bit UART, Variable Baud Rate.............................................. 270 22.2.Multiprocessor Communications .................................................................... 271 22.2.1.Configuration of a Masked Address ....................................................... 271 22.2.2.Broadcast Addressing ............................................................................ 271 22.3.Frame and Transmission Error Detection....................................................... 272 23. UART1.................................................................................................................... 277 23.1.Enhanced Baud Rate Generation................................................................... 278 23.2.Operational Modes ......................................................................................... 279 23.2.1.8-Bit UART ............................................................................................. 279 23.2.2.9-Bit UART ............................................................................................. 280 23.3.Multiprocessor Communications .................................................................... 281 24. Timers.................................................................................................................... 287 24.1.Timer 0 and Timer 1 ....................................................................................... 287 24.1.1.Mode 0: 13-bit Counter/Timer ................................................................ 287 24.1.2.Mode 1: 16-bit Counter/Timer ................................................................ 289 24.1.3.Mode 2: 8-bit Counter/Timer with Auto-Reload...................................... 289 24.1.4.Mode 3: Two 8-bit Counter/Timers (Timer 0 Only)................................. 290 24.2.Timer 2, Timer 3, and Timer 4 ........................................................................ 295 24.2.1.Configuring Timer 2, 3, and 4 to Count Down........................................ 295 24.2.2.Capture Mode ........................................................................................ 296 24.2.3.Auto-Reload Mode ................................................................................. 297 24.2.4.Toggle Output Mode .............................................................................. 298 25. Programmable Counter Array ............................................................................. 303 25.1.PCA Counter/Timer ........................................................................................ 304 25.2.Capture/Compare Modules ............................................................................ 305 25.2.1.Edge-triggered Capture Mode................................................................ 306 25.2.2.Software Timer (Compare) Mode........................................................... 307 25.2.3.High Speed Output Mode....................................................................... 308 25.2.4.Frequency Output Mode ........................................................................ 309 25.2.5.8-Bit Pulse Width Modulator Mode......................................................... 310 25.2.6.16-Bit Pulse Width Modulator Mode....................................................... 311 25.3.Register Descriptions for PCA0...................................................................... 312 26. JTAG (IEEE 1149.1) .............................................................................................. 317 26.1.Boundary Scan ............................................................................................... 318 26.1.1.EXTEST Instruction................................................................................ 321 26.1.2.SAMPLE Instruction ............................................................................... 321 26.1.3.BYPASS Instruction ............................................................................... 321 26.1.4.IDCODE Instruction................................................................................ 321 Rev. 1.3 7 C8051F060/1/2/3/4/5/6/7 26.2.Flash Programming Commands..................................................................... 322 26.3.Debug Support ............................................................................................... 325 27. Document Change List ........................................................................................ 327 27.1.Revision 1.1 to Revision 1.2 ........................................................................... 327 8 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 List of Figures 1. System Overview.................................................................................................... 19 Figure 1.1. C8051F060 / C8051F062 Block Diagram .............................................. 21 Figure 1.2. C8051F061 / C8051F063 Block Diagram .............................................. 22 Figure 1.3. C8051F064 / C8051F066 Block Diagram .............................................. 23 Figure 1.4. C8051F065 / C8051F067 Block Diagram .............................................. 24 Figure 1.5. Comparison of Peak MCU Execution Speeds ....................................... 25 Figure 1.6. On-Board Clock and Reset .................................................................... 26 Figure 1.7. On-Chip Memory Map............................................................................ 27 Figure 1.8. Development/In-System Debug Diagram............................................... 28 Figure 1.9. Digital Crossbar Diagram ....................................................................... 29 Figure 1.10. PCA Block Diagram.............................................................................. 30 Figure 1.11. CAN Controller Overview ..................................................................... 31 Figure 1.12. 16-Bit ADC Block Diagram ................................................................... 33 Figure 1.13. 10-Bit ADC Diagram............................................................................. 34 Figure 1.14. DAC System Block Diagram ................................................................ 35 Figure 1.15. Comparator Block Diagram .................................................................. 36 2. Absolute Maximum Ratings .................................................................................. 37 3. Global DC Electrical Characteristics .................................................................... 38 4. Pinout and Package Definitions............................................................................ 39 Figure 4.1. C8051F060 / C8051F062 Pinout Diagram (TQFP-100)......................... 45 Figure 4.2. C8051F064 / C8051F066 Pinout Diagram (TQFP-100)......................... 46 Figure 4.3. TQFP-100 Package Drawing ................................................................. 47 Figure 4.4. C8051F061 / C8051F063 Pinout Diagram (TQFP-64)........................... 48 Figure 4.5. C8051F065 / C8051F067 Pinout Diagram (TQFP-64)........................... 49 Figure 4.6. TQFP-64 Package Drawing ................................................................... 50 5. 16-Bit ADCs (ADC0 and ADC1) ............................................................................. 51 Figure 5.1. 16-Bit ADC0 and ADC1 Control Path Diagram ...................................... 51 Figure 5.2. 16-bit ADC0 and ADC1 Data Path Diagram .......................................... 52 Figure 5.3. Voltage Reference Block Diagram ......................................................... 53 Figure 5.4. ADC Track and Conversion Example Timing......................................... 55 Figure 5.5. ADC0 and ADC1 Equivalent Input Circuits ............................................ 56 Figure 5.6. AMX0SL: AMUX Configuration Register................................................ 57 Figure 5.7. ADC0CF: ADC0 Configuration Register ................................................ 58 Figure 5.8. ADC1CF: ADC1 Configuration Register ................................................ 59 Figure 5.9. ADC0CN: ADC0 Control Register.......................................................... 60 Figure 5.10. ADC1CN: ADC1 Control Register ........................................................ 61 Figure 5.11. REF0CN: Reference Control Register 0 .............................................. 62 Figure 5.12. REF1CN: Reference Control Register 1 .............................................. 62 Figure 5.13. ADC0H: ADC0 Data Word MSB Register ............................................ 63 Figure 5.14. ADC0L: ADC0 Data Word LSB Register.............................................. 63 Figure 5.15. ADC0 Data Word Example................................................................... 64 Figure 5.16. ADC1H: ADC1 Data Word MSB Register ............................................ 65 Rev. 1.3 9 C8051F060/1/2/3/4/5/6/7 Figure 5.17. ADC1L: ADC1 Data Word LSB Register.............................................. 65 Figure 5.18. ADC1 Data Word Example................................................................... 65 Figure 5.19. Calibration Coefficient Locations.......................................................... 66 Figure 5.20. Offset and Gain Register Mapping ....................................................... 67 Figure 5.21. Offset and Gain Calibration Block Diagram.......................................... 67 Figure 5.22. ADC0CPT: ADC Calibration Pointer Register ...................................... 68 Figure 5.23. ADC0CCF: ADC Calibration Coefficient Register ................................ 68 Figure 5.24. ADC0GTH: ADC0 Greater-Than Data High Byte Register .................. 69 Figure 5.25. ADC0GTL: ADC0 Greater-Than Data Low Byte Register.................... 69 Figure 5.26. ADC0LTH: ADC0 Less-Than Data High Byte Register........................ 70 Figure 5.27. ADC0LTL: ADC0 Less-Than Data Low Byte Register ......................... 70 Figure 5.28. 16-Bit ADC0 Window Interrupt Example: Single-Ended Data .............. 71 Figure 5.29. 16-Bit ADC0 Window Interrupt Example: Differential Data .................. 72 6. Direct Memory Access Interface (DMA0) ............................................................. 75 Figure 6.1. DMA0 Block Diagram............................................................................. 75 Figure 6.2. DMA Mode 0 Operation ......................................................................... 77 Figure 6.3. DMA Mode 1 Operation ......................................................................... 78 Figure 6.4. DMA0CN: DMA0 Control Register ......................................................... 80 Figure 6.5. DMA0CF: DMA0 Configuration Register................................................ 81 Figure 6.6. DMA0IPT: DMA0 Instruction Write Address Register ............................ 82 Figure 6.7. DMA0IDT: DMA0 Instruction Write Data Register ................................. 82 Figure 6.8. DMA0BND: DMA0 Instruction Boundary Register ................................. 83 Figure 6.9. DMA0ISW: DMA0 Instruction Status Register ....................................... 83 Figure 6.10. DMA0DAH: DMA0 Data Address Beginning MSB Register................. 84 Figure 6.11. DMA0DAL: DMA0 Data Address Beginning LSB Register .................. 84 Figure 6.12. DMA0DSH: DMA0 Data Address Pointer MSB Register ..................... 84 Figure 6.13. DMA0DSL: DMA0 Data Address Pointer LSB Register ....................... 84 Figure 6.14. DMA0CTH: DMA0 Repeat Counter Limit MSB Register...................... 85 Figure 6.15. DMA0CTL: DMA0 Repeat Counter Limit LSB Register ....................... 85 Figure 6.16. DMA0CSH: DMA0 Repeat Counter MSB Register .............................. 85 Figure 6.17. DMA0CSL: DMA0 Repeat Counter LSB Register................................ 85 7. 10-Bit ADC (ADC2, C8051F060/1/2/3).................................................................... 87 Figure 7.1. ADC2 Functional Block Diagram............................................................ 87 Figure 7.2. Temperature Sensor Transfer Function ................................................. 89 Figure 7.3. 10-Bit ADC Track and Conversion Example Timing .............................. 90 Figure 7.4. ADC2 Equivalent Input Circuits.............................................................. 91 Figure 7.5. AMX2CF: AMUX2 Configuration Register ............................................. 92 Figure 7.6. AMX2SL: AMUX2 Channel Select Register........................................... 93 Figure 7.7. ADC2CF: ADC2 Configuration Register ................................................ 94 Figure 7.8. ADC2H: ADC2 Data Word MSB Register .............................................. 95 Figure 7.9. ADC2L: ADC2 Data Word LSB Register................................................ 95 Figure 7.10. ADC2CN: ADC2 Control Register ........................................................ 96 Figure 7.11. ADC2GTH: ADC2 Greater-Than Data High Byte Register .................. 97 Figure 7.12. ADC2GTL: ADC2 Greater-Than Data Low Byte Register.................... 97 Figure 7.13. ADC2LTH: ADC2 Less-Than Data High Byte Register........................ 98 10 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 7.14. ADC2LTL: ADC2 Less-Than Data Low Byte Register ......................... 98 Figure 7.15. ADC Window Compare Example: Right-Justified Single-Ended Data . 99 Figure 7.16. ADC Window Compare Example: Left-Justified Single-Ended Data.... 99 Figure 7.17. ADC Window Compare Example: Right-Justified Differential Data.... 100 Figure 7.18. ADC Window Compare Example: Left-Justified Differential Data ...... 100 8. DACs, 12-Bit Voltage Mode (DAC0 and DAC1, C8051F060/1/2/3) .................... 103 Figure 8.1. DAC Functional Block Diagram............................................................ 103 Figure 8.2. DAC0H: DAC0 High Byte Register ...................................................... 105 Figure 8.3. DAC0L: DAC0 Low Byte Register........................................................ 105 Figure 8.4. DAC0CN: DAC0 Control Register........................................................ 106 Figure 8.5. DAC1H: DAC1 High Byte Register ...................................................... 107 Figure 8.6. DAC1L: DAC1 Low Byte Register........................................................ 107 Figure 8.7. DAC1CN: DAC1 Control Register........................................................ 108 9. Voltage Reference 2 (C8051F060/2) .................................................................... 111 Figure 9.1. Voltage Reference Functional Block Diagram ..................................... 111 Figure 9.2. REF2CN: Reference Control Register 2 .............................................. 112 10. Voltage Reference 2 (C8051F061/3) ................................................................... 113 Figure 10.1. Voltage Reference Functional Block Diagram.................................... 113 Figure 10.2. REF2CN: Reference Control Register 2 ............................................ 114 11. Voltage Reference 2 (C8051F064/5/6/7) .............................................................. 115 Figure 11.1. Voltage Reference Functional Block Diagram.................................... 115 Figure 11.2. REF2CN: Reference Control Register 2 ............................................ 116 12. Comparators ......................................................................................................... 117 Figure 12.1. Comparator Functional Block Diagram .............................................. 117 Figure 12.2. Comparator Hysteresis Plot ............................................................... 118 Figure 12.3. CPTnCN: Comparator 0, 1, and 2 Control Register ........................... 120 Figure 12.4. CPTnMD: Comparator Mode Selection Register ............................... 121 13. CIP-51 Microcontroller ......................................................................................... 123 Figure 13.1. CIP-51 Block Diagram....................................................................... 124 Figure 13.2. Memory Map ...................................................................................... 130 Figure 13.3. SFR Page Stack................................................................................. 133 Figure 13.4. SFR Page Stack While Using SFR Page 0x0F To Access Port 5...... 134 Figure 13.5. SFR Page Stack After ADC2 Window Comparator Interrupt Occurs . 135 Figure 13.6. SFR Page Stack Upon PCA Interrupt Occurring During an ADC2 ISR.... 136 Figure 13.7. SFR Page Stack Upon Return From PCA Interrupt ........................... 137 Figure 13.8. SFR Page Stack Upon Return From ADC2 Window Interrupt ........... 138 Figure 13.9. SFRPGCN: SFR Page Control Register ............................................ 139 Figure 13.10. SFRPAGE: SFR Page Register ....................................................... 139 Figure 13.11. SFRNEXT: SFR Next Register......................................................... 140 Figure 13.12. SFRLAST: SFR Last Register.......................................................... 140 Figure 13.13. SP: Stack Pointer ............................................................................. 148 Figure 13.14. DPL: Data Pointer Low Byte............................................................. 148 Figure 13.15. DPH: Data Pointer High Byte ........................................................... 148 Figure 13.16. PSW: Program Status Word............................................................. 149 Rev. 1.3 11 C8051F060/1/2/3/4/5/6/7 Figure 13.17. ACC: Accumulator............................................................................ 150 Figure 13.18. B: B Register .................................................................................... 150 Figure 13.19. IE: Interrupt Enable .......................................................................... 154 Figure 13.20. IP: Interrupt Priority .......................................................................... 155 Figure 13.21. EIE1: Extended Interrupt Enable 1................................................... 156 Figure 13.22. EIE2: Extended Interrupt Enable 2................................................... 157 Figure 13.23. EIP1: Extended Interrupt Priority 1................................................... 158 Figure 13.24. EIP2: Extended Interrupt Priority 2................................................... 159 Figure 13.25. PCON: Power Control ...................................................................... 161 14. Reset Sources....................................................................................................... 163 Figure 14.1. Reset Sources.................................................................................... 163 Figure 14.2. Reset Timing ...................................................................................... 164 Figure 14.3. WDTCN: Watchdog Timer Control Register....................................... 167 Figure 14.4. RSTSRC: Reset Source Register ...................................................... 168 15. Oscillators ............................................................................................................. 171 Figure 15.1. Oscillator Diagram.............................................................................. 171 Figure 15.2. OSCICL: Internal Oscillator Calibration Register ............................... 172 Figure 15.3. OSCICN: Internal Oscillator Control Register .................................... 172 Figure 15.4. CLKSEL: Oscillator Clock Selection Register .................................... 173 Figure 15.5. OSCXCN: External Oscillator Control Register.................................. 174 16. Flash Memory ....................................................................................................... 177 Figure 16.1. C8051F060/1/2/3/4/5 Flash Program Memory Map and Security Bytes .. 180 Figure 16.2. C8051F066/7 Flash Program Memory Map and Security Bytes ........ 181 Figure 16.3. FLACL: Flash Access Limit ................................................................ 182 Figure 16.4. FLSCL: Flash Memory Control........................................................... 184 Figure 16.5. PSCTL: Program Store Read/Write Control....................................... 185 17. External Data Memory Interface and On-Chip XRAM........................................ 187 Figure 17.1. EMI0CN: External Memory Interface Control ..................................... 189 Figure 17.2. EMI0CF: External Memory Configuration........................................... 189 Figure 17.3. Multiplexed Configuration Example.................................................... 190 Figure 17.4. Non-multiplexed Configuration Example ............................................ 191 Figure 17.5. EMIF Operating Modes ...................................................................... 192 Figure 17.6. EMI0TC: External Memory Timing Control......................................... 194 Figure 17.7. Non-multiplexed 16-bit MOVX Timing ................................................ 196 Figure 17.8. Non-multiplexed 8-bit MOVX without Bank Select Timing ................. 197 Figure 17.9. Non-multiplexed 8-bit MOVX with Bank Select Timing ...................... 198 Figure 17.10. Multiplexed 16-bit MOVX Timing...................................................... 199 Figure 17.11. Multiplexed 8-bit MOVX without Bank Select Timing ....................... 200 Figure 17.12. Multiplexed 8-bit MOVX with Bank Select Timing ............................ 201 18. Port Input/Output.................................................................................................. 203 Figure 18.1. Port I/O Cell Block Diagram ............................................................... 203 Figure 18.2. Port I/O Functional Block Diagram ..................................................... 204 Figure 18.3. Priority Crossbar Decode Table ......................................................... 205 Figure 18.4. Crossbar Example:............................................................................. 209 12 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 18.5. XBR0: Port I/O Crossbar Register 0................................................... 210 Figure 18.6. XBR1: Port I/O Crossbar Register 1................................................... 211 Figure 18.7. XBR2: Port I/O Crossbar Register 2................................................... 212 Figure 18.8. XBR3: Port I/O Crossbar Register 3................................................... 213 Figure 18.9. P0: Port0 Data Register ..................................................................... 214 Figure 18.10. P0MDOUT: Port0 Output Mode Register ......................................... 214 Figure 18.11. P1: Port1 Data Register ................................................................... 215 Figure 18.12. P1MDIN: Port1 Input Mode Register................................................ 215 Figure 18.13. P1MDOUT: Port1 Output Mode Register ......................................... 216 Figure 18.14. P2: Port2 Data Register ................................................................... 216 Figure 18.15. P2MDIN: Port2 Input Mode Register................................................ 217 Figure 18.16. P2MDOUT: Port2 Output Mode Register ......................................... 217 Figure 18.17. P3: Port3 Data Register ................................................................... 218 Figure 18.18. P3MDOUT: Port3 Output Mode Register ......................................... 218 Figure 18.19. P4: Port4 Data Register ................................................................... 221 Figure 18.20. P4MDOUT: Port4 Output Mode Register ......................................... 221 Figure 18.21. P5: Port5 Data Register ................................................................... 222 Figure 18.22. P5MDOUT: Port5 Output Mode Register ......................................... 222 Figure 18.23. P6: Port6 Data Register ................................................................... 223 Figure 18.24. P6MDOUT: Port6 Output Mode Register ......................................... 223 Figure 18.25. P7: Port7 Data Register ................................................................... 224 Figure 18.26. P7MDOUT: Port7 Output Mode Register ......................................... 224 19. Controller Area Network (CAN0, C8051F060/1/2/3) ........................................... 225 Figure 19.1. CAN Controller Diagram..................................................................... 226 Figure 19.2. Typical CAN Bus Configuration.......................................................... 226 Figure 19.3. CAN0DATH: CAN Data Access Register High Byte .......................... 231 Figure 19.4. CAN0DATL: CAN Data Access Register Low Byte............................ 231 Figure 19.5. CAN0ADR: CAN Address Index Register .......................................... 232 Figure 19.6. CAN0CN: CAN Control Register ........................................................ 232 Figure 19.7. CAN0TST: CAN Test Register ........................................................... 233 Figure 19.8. CAN0STA: CAN Status Register........................................................ 233 20. System Management BUS / I2C BUS (SMBUS0)................................................ 235 Figure 20.1. SMBus0 Block Diagram ..................................................................... 235 Figure 20.2. Typical SMBus Configuration ............................................................. 236 Figure 20.3. SMBus Transaction ............................................................................ 237 Figure 20.4. Typical Master Transmitter Sequence................................................ 238 Figure 20.5. Typical Master Receiver Sequence.................................................... 238 Figure 20.6. Typical Slave Transmitter Sequence.................................................. 239 Figure 20.7. Typical Slave Receiver Sequence...................................................... 240 Figure 20.8. SMB0CN: SMBus0 Control Register.................................................. 243 Figure 20.9. SMB0CR: SMBus0 Clock Rate Register............................................ 244 Figure 20.10. SMB0DAT: SMBus0 Data Register.................................................. 245 Figure 20.11. SMB0ADR: SMBus0 Address Register............................................ 246 Figure 20.12. SMB0STA: SMBus0 Status Register ............................................... 247 21. Enhanced Serial Peripheral Interface (SPI0)...................................................... 251 Rev. 1.3 13 C8051F060/1/2/3/4/5/6/7 Figure 21.1. SPI Block Diagram ............................................................................. 251 Figure 21.2. Multiple-Master Mode Connection Diagram ....................................... 254 Figure 21.3. 3-Wire Single Master and 3-Wire Single Slave Mode Connection Diagram 254 Figure 21.4. 4-Wire Single Master Mode and 4-Wire Slave Mode Connection Diagram 254 Figure 21.5. Master Mode Data/Clock Timing ........................................................ 256 Figure 21.6. Slave Mode Data/Clock Timing (CKPHA = 0) .................................... 257 Figure 21.7. Slave Mode Data/Clock Timing (CKPHA = 1) .................................... 257 Figure 21.8. SPI0CFG: SPI0 Configuration Register ............................................. 258 Figure 21.9. SPI0CN: SPI0 Control Register.......................................................... 259 Figure 21.10. SPI0CKR: SPI0 Clock Rate Register ............................................... 260 Figure 21.11. SPI0DAT: SPI0 Data Register.......................................................... 261 Figure 21.12. SPI Master Timing (CKPHA = 0)...................................................... 262 Figure 21.13. SPI Master Timing (CKPHA = 1)...................................................... 262 Figure 21.14. SPI Slave Timing (CKPHA = 0)........................................................ 263 Figure 21.15. SPI Slave Timing (CKPHA = 1)........................................................ 263 22. UART0.................................................................................................................... 265 Figure 22.1. UART0 Block Diagram ....................................................................... 265 Figure 22.2. UART0 Mode 0 Timing Diagram ........................................................ 267 Figure 22.3. UART0 Mode 0 Interconnect.............................................................. 267 Figure 22.4. UART0 Mode 1 Timing Diagram ........................................................ 267 Figure 22.5. UART0 Modes 2 and 3 Timing Diagram ............................................ 269 Figure 22.6. UART0 Modes 1, 2, and 3 Interconnect Diagram .............................. 270 Figure 22.7. UART Multi-Processor Mode Interconnect Diagram .......................... 272 Figure 22.8. SCON0: UART0 Control Register ...................................................... 274 Figure 22.9. SSTA0: UART0 Status and Clock Selection Register........................ 275 Figure 22.10. SBUF0: UART0 Data Buffer Register .............................................. 276 Figure 22.11. SADDR0: UART0 Slave Address Register ...................................... 276 Figure 22.12. SADEN0: UART0 Slave Address Enable Register .......................... 276 23. UART1.................................................................................................................... 277 Figure 23.1. UART1 Block Diagram ....................................................................... 277 Figure 23.2. UART1 Baud Rate Logic .................................................................... 278 Figure 23.3. UART Interconnect Diagram .............................................................. 279 Figure 23.4. 8-Bit UART Timing Diagram............................................................... 279 Figure 23.5. 9-Bit UART Timing Diagram............................................................... 280 Figure 23.6. UART Multi-Processor Mode Interconnect Diagram .......................... 281 Figure 23.7. SCON1: Serial Port 1 Control Register .............................................. 282 Figure 23.8. SBUF1: Serial (UART1) Port Data Buffer Register ............................ 283 24. Timers.................................................................................................................... 287 Figure 24.1. T0 Mode 0 Block Diagram.................................................................. 288 Figure 24.2. T0 Mode 2 Block Diagram.................................................................. 289 Figure 24.3. T0 Mode 3 Block Diagram.................................................................. 290 Figure 24.4. TCON: Timer Control Register ........................................................... 291 Figure 24.5. TMOD: Timer Mode Register ............................................................. 292 14 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 24.6. CKCON: Clock Control Register ........................................................ 293 Figure 24.7. TL0: Timer 0 Low Byte ....................................................................... 294 Figure 24.8. TL1: Timer 1 Low Byte ....................................................................... 294 Figure 24.9. TH0: Timer 0 High Byte...................................................................... 294 Figure 24.10. TH1: Timer 1 High Byte.................................................................... 294 Figure 24.11. T2, 3, and 4 Capture Mode Block Diagram ...................................... 296 Figure 24.12. T2, 3, and 4 Auto-reload Mode Block Diagram ................................ 297 Figure 24.13. TMRnCN: Timer 2, 3, and 4 Control Registers ................................ 299 Figure 24.14. TMRnCF: Timer 2, 3, and 4 Configuration Registers ....................... 300 Figure 24.15. RCAPnL: Timer 2, 3, and 4 Capture Register Low Byte .................. 301 Figure 24.16. RCAPnH: Timer 2, 3, and 4 Capture Register High Byte................. 301 Figure 24.17. TMRnL: Timer 2, 3, and 4 Low Byte................................................. 301 Figure 24.18. TMRnH: Timer 2, 3, and 4 High Byte ............................................... 302 25. Programmable Counter Array ............................................................................. 303 Figure 25.1. PCA Block Diagram............................................................................ 303 Figure 25.2. PCA Counter/Timer Block Diagram.................................................... 304 Figure 25.3. PCA Interrupt Block Diagram ............................................................. 305 Figure 25.4. PCA Capture Mode Diagram.............................................................. 306 Figure 25.5. PCA Software Timer Mode Diagram .................................................. 307 Figure 25.6. PCA High Speed Output Mode Diagram............................................ 308 Figure 25.7. PCA Frequency Output Mode ............................................................ 309 Figure 25.8. PCA 8-Bit PWM Mode Diagram ......................................................... 310 Figure 25.9. PCA 16-Bit PWM Mode...................................................................... 311 Figure 25.10. PCA0CN: PCA Control Register ...................................................... 312 Figure 25.11. PCA0MD: PCA0 Mode Register....................................................... 313 Figure 25.12. PCA0CPMn: PCA0 Capture/Compare Mode Registers................... 314 Figure 25.13. PCA0L: PCA0 Counter/Timer Low Byte........................................... 315 Figure 25.14. PCA0H: PCA0 Counter/Timer High Byte ......................................... 315 Figure 25.15. PCA0CPLn: PCA0 Capture Module Low Byte ................................. 316 Figure 25.16. PCA0CPHn: PCA0 Capture Module High Byte................................ 316 26. JTAG (IEEE 1149.1) .............................................................................................. 317 Figure 26.1. IR: JTAG Instruction Register............................................................. 317 Figure 26.2. DEVICEID: JTAG Device ID Register ................................................ 321 Figure 26.3. FLASHCON: JTAG Flash Control Register........................................ 323 Figure 26.4. FLASHDAT: JTAG Flash Data Register............................................. 324 Figure 26.5. FLASHADR: JTAG Flash Address Register....................................... 324 27. Document Change List ........................................................................................ 327 Rev. 1.3 15 C8051F060/1/2/3/4/5/6/7 16 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 List of Tables 1. System Overview ................................................................................................... 19 Table 1.1.Product Selection Guide .......................................................................... 20 2. Absolute Maximum Ratings ................................................................................. 37 Table 2.1.Absolute Maximum Ratings* ................................................................... 37 3. Global DC Electrical Characteristics ................................................................... 38 Table 3.1.Global DC Electrical Characteristics ....................................................... 38 4. Pinout and Package Definitions ........................................................................... 39 Table 4.1.Pin Definitions ......................................................................................... 39 5. 16-Bit ADCs (ADC0 and ADC1) ............................................................................ 51 Table 5.1.Conversion Timing (tConv) ...................................................................... 55 Table 5.2.16-Bit ADC0 and ADC1 Electrical Characteristics .................................. 73 Table 5.3.Voltage Reference 0 and 1 Electrical Characteristics ............................. 74 6. Direct Memory Access Interface (DMA0) ............................................................ 75 Table 6.1.DMA0 Instruction Set .............................................................................. 76 7. 10-Bit ADC (ADC2, C8051F060/1/2/3) ................................................................... 87 Table 7.1.ADC2 Electrical Characteristics ............................................................ 101 8. DACs, 12-Bit Voltage Mode (DAC0 and DAC1, C8051F060/1/2/3) ................... 103 Table 8.1.DAC Electrical Characteristics .............................................................. 109 9. Voltage Reference 2 (C8051F060/2) ................................................................... 111 Table 9.1.Voltage Reference Electrical Characteristics ........................................ 112 10. Voltage Reference 2 (C8051F061/3) .................................................................. 113 Table 10.1.Voltage Reference Electrical Characteristics ...................................... 114 11. Voltage Reference 2 (C8051F064/5/6/7) ............................................................. 115 Table 11.1.Voltage Reference Electrical Characteristics ...................................... 116 12. Comparators ........................................................................................................ 117 Table 12.1.Comparator Electrical Characteristics ................................................. 122 13. CIP-51 Microcontroller ........................................................................................ 123 Table 13.1.CIP-51 Instruction Set Summary ......................................................... 126 Table 13.2.Special Function Register (SFR) Memory Map ................................... 141 Table 13.3.Special Function Registers .................................................................. 143 Table 13.4.Interrupt Summary ............................................................................... 152 14. Reset Sources ...................................................................................................... 163 Table 14.1.Reset Electrical Characteristics ........................................................... 169 15. Oscillators ............................................................................................................ 171 Table 15.1.Internal Oscillator Electrical Characteristics ........................................ 173 16. Flash Memory ...................................................................................................... 177 Table 16.1.Flash Electrical Characteristics ........................................................... 178 17. External Data Memory Interface and On-Chip XRAM ....................................... 187 Table 17.1.AC Parameters for External Memory Interface .................................... 202 18. Port Input/Output ................................................................................................. 203 Table 18.1.Port I/O DC Electrical Characteristics .................................................. 203 19. Controller Area Network (CAN0, C8051F060/1/2/3) .......................................... 225 Rev. 1.3 17 C8051F060/1/2/3/4/5/6/7 Table 19.1.CAN Register Index and Reset Values ............................................... 229 20. System Management BUS / I2C BUS (SMBUS0) ............................................... 235 Table 20.1.SMB0STA Status Codes and States ................................................... 248 21. Enhanced Serial Peripheral Interface (SPI0) ..................................................... 251 Table 21.1.SPI Slave Timing Parameters ............................................................. 264 22. UART0 ................................................................................................................... 265 Table 22.1.UART0 Modes ..................................................................................... 266 Table 22.2.Oscillator Frequencies for Standard Baud Rates ................................ 273 23. UART1 ................................................................................................................... 277 Table 23.1.Timer Settings for Standard Baud Rates Using the Internal Oscillator 284 Table 23.2.Timer Settings for Standard Baud Rates Using an External Oscillator 284 Table 23.3.Timer Settings for Standard Baud Rates Using an External Oscillator 285 Table 23.4.Timer Settings for Standard Baud Rates Using an External Oscillator 285 Table 23.5.Timer Settings for Standard Baud Rates Using an External Oscillator 286 Table 23.6.Timer Settings for Standard Baud Rates Using an External Oscillator 286 24. Timers ................................................................................................................... 287 25. Programmable Counter Array ............................................................................ 303 Table 25.1.PCA Timebase Input Options .............................................................. 304 Table 25.2.PCA0CPM Register Settings for PCA Capture/Compare Modules ..... 305 26. JTAG (IEEE 1149.1) ............................................................................................. 317 Table 26.1.Boundary Data Register Bit Definitions (C8051F060/2/4/6) ................ 318 Table 26.2.Boundary Data Register Bit Definitions (C8051F061/3/5/7) ................ 320 27. Document Change List ....................................................................................... 327 18 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1. System Overview The C8051F06x family of devices are fully integrated mixed-signal System-on-a-Chip MCUs with 59 digital I/O pins (C8051F060/2/4/6) or 24 digital I/O pins (C8051F061/3/5/7), and two integrated 16-bit 1 Msps ADCs. Highlighted features are listed below; refer to Table 1.1 for specific product feature selection. • • • • • • • • • • • • • High-Speed pipelined 8051-compatible CIP-51 microcontroller core (up to 25 MIPS) Two 16-bit 1 Msps ADCs with a Direct Memory Access controller Controller Area Network (CAN 2.0B) Controller with 32 message objects, each with its own indentifier mask (C8051F060/1/2/3) In-system, full-speed, non-intrusive debug interface on-chip 10-bit 200 ksps ADC with PGA and 8-channel analog multiplexer (C8051F060/1/2/3) Two 12-bit DACs with programmable update scheduling (C8051F060/1/2/3) 64 kB (C8051F060/1/2/3/4/5) or 32 kB (C8051F066/7) of in-system programmable Flash memory 4352 (4096 + 256) bytes of on-chip RAM External Data Memory Interface with 64 kB direct address space (C8051F060/2/4/6) SPI, SMBus/I2C, and (2) UART serial interfaces implemented in hardware Five general purpose 16-bit Timers Programmable Counter/Timer Array with six capture/compare modules On-chip Watchdog Timer, VDD Monitor, and Temperature Sensor With on-chip VDD monitor, Watchdog Timer, and clock oscillator, the C8051F06x family of devices are truly stand-alone System-on-a-Chip solutions. All analog and digital peripherals are enabled/disabled and configured by user firmware. The Flash memory can be reprogrammed even in-circuit, providing non-volatile data storage, and also allowing field upgrades of the 8051 firmware. On-board JTAG debug circuitry allows non-intrusive (uses no on-chip resources), full speed, in-circuit debugging using the production MCU installed in the final application. This debug system supports inspection and modification of memory and registers, setting breakpoints, watchpoints, single stepping, Run and Halt commands. All analog and digital peripherals are fully functional while debugging using JTAG. Each MCU is specified for 2.7 to 3.6 V operation over the industrial temperature range (-45 to +85 °C). The C8051F060/2/4/6 are available in a 100-pin TQFP package and the C8051F061/3/5/7 are available in a 64-pin TQFP package (see block diagrams in Figure 1.1, Figure 1.2, Figure 1.3 and Figure 1.4). Rev. 1.319 C8051F060/1/2/3/4/5/6/7 Timers (16-bit) Programmable Counter Array Voltage Reference Temperature Sensor DAC Resolution (bits) DAC Outputs Analog Comparators  59 ±0.75 8   12 2 3 100 TQFP C8051F061-GQ 25 64 k 4352 -   2 5  24 ±0.75 8   12 2 3 C8051F062-GQ* 25 64 k 4352    2 5  59 ±1.5 8   12 2 3 100 TQFP C8051F063-GQ* 25 64 k 4352 -   2 5  24 ±1.5 8   12 2 3 C8051F064-GQ* 25 64 k 4352   - 2 5  59 ±0.75 -  - - - 3 100 TQFP C8051F065-GQ* 25 64 k 4352 -  - 2 5  24 ±0.75 -  - - - 3 C8051F066-GQ* 25 32 k 4352   - 2 5  59 ±0.75 -  - - - 3 100 TQFP C8051F067-GQ* 25 32 k 4352 -  - 2 5  24 ±0.75 -  - - - 3 *Note: Not recommended for new designs. 20 Rev. 1.3 Package UARTS 5 10-bit 200 ksps ADC Inputs CAN 2 Digital Port I/O’s SMBus/I2C and SPI  RAM  Flash Memory C8051F060-GQ 25 64 k 4352  MIPS (Peak) External Memory Interface 16-bit 1 Msps ADC Typical INL (LSBs) Table 1.1. Product Selection Guide 64 TQFP 64 TQFP 64 TQFP 64 TQFP C8051F060/1/2/3/4/5/6/7 Figure 1.1. C8051F060 / C8051F062 Block Diagram Rev. 1.321 C8051F060/1/2/3/4/5/6/7 Figure 1.2. C8051F061 / C8051F063 Block Diagram 22 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 1.3. C8051F064 / C8051F066 Block Diagram Rev. 1.323 C8051F060/1/2/3/4/5/6/7 Figure 1.4. C8051F065 / C8051F067 Block Diagram 24 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1.1. CIP-51™ Microcontroller Core 1.1.1. Fully 8051 Compatible The C8051F06x family of devices utilizes Silicon Labs' proprietary CIP-51 microcontroller core. The CIP51 is fully compatible with the MCS-51™ instruction set; standard 803x/805x assemblers and compilers can be used to develop software. The core has all the peripherals included with a standard 8052, including five 16-bit counter/timers, two full-duplex UARTs, 256 bytes of internal RAM, 128 byte Special Function Register (SFR) address space, and bit-addressable I/O Ports. 1.1.2. Improved Throughput The CIP-51 employs a pipelined architecture that greatly increases its instruction throughput over the standard 8051 architecture. In a standard 8051, all instructions except for MUL and DIV take 12 or 24 system clock cycles to execute with a maximum system clock of 12-to-24 MHz. By contrast, the CIP-51 core executes 70% of its instructions in one or two system clock cycles, with only four instructions taking more than four system clock cycles. The CIP-51 has a total of 109 instructions. The table below shows the total number of instructions that require each execution time. Clocks to Execute 1 2 2/3 3 3/4 4 4/5 5 8 Number of Instructions 26 50 5 14 7 3 1 2 1 With the CIP-51's maximum system clock at 25 MHz, it has a peak throughput of 25 MIPS. Figure 1.5 shows a comparison of peak throughputs of various 8-bit microcontroller cores with their maximum system clocks. Figure 1.5. Comparison of Peak MCU Execution Speeds Rev. 1.325 C8051F060/1/2/3/4/5/6/7 1.1.3. Additional Features The C8051F06x MCU family includes several key enhancements to the CIP-51 core and peripherals to improve overall performance and ease of use in end applications. The extended interrupt handler provides 22 interrupt sources into the CIP-51, allowing the numerous analog and digital peripherals to interrupt the controller. An interrupt driven system requires less intervention by the MCU, giving it more effective throughput. The extra interrupt sources are very useful when building multi-tasking, real-time systems. There are up to seven reset sources for the MCU: an on-board VDD monitor, a Watchdog Timer, a missing clock detector, a voltage level detection from Comparator0, a forced software reset, the CNVSTR2 input pin, and the /RST pin. The /RST pin is bi-directional, accommodating an external reset, or allowing the internally generated POR to be output on the /RST pin. Each reset source except for the VDD monitor and Reset Input pin may be disabled by the user in software; the VDD monitor is enabled/disabled via the MONEN pin. The Watchdog Timer may be permanently enabled in software after a power-on reset during MCU initialization. The MCU has an internal, stand alone clock generator which is used by default as the system clock after any reset. If desired, the clock source may be switched on the fly to the external oscillator, which can use a crystal, ceramic resonator, capacitor, RC, or external clock source to generate the system clock. This can be extremely useful in low power applications, allowing the MCU to run from a slow (power saving) external crystal source, while periodically switching to the fast (up to 25 MHz) internal oscillator as needed. Figure 1.6. On-Board Clock and Reset 26 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1.2. On-Chip Memory The CIP-51 has a standard 8051 program and data address configuration. It includes 256 bytes of data RAM, with the upper 128 bytes dual-mapped. Indirect addressing accesses the upper 128 bytes of general purpose RAM, and direct addressing accesses the 128 byte SFR address space. The CIP-51 SFR address space contains up to 256 SFR Pages. In this way, the CIP-51 MCU can accommodate the many SFRs required to control and configure the various peripherals featured on the device. The lower 128 bytes of RAM are accessible via direct and indirect addressing. The first 32 bytes are addressable as four banks of general purpose registers, and the next 16 bytes can be byte addressable or bit addressable. The CIP-51 in the C8051F060/1/2/3/4/5/6/7 MCUs additionally has an on-chip 4 kB RAM block. The onchip 4 kB block can be addressed over the entire 64 k external data memory address range (overlapping 4 k boundaries). The C8051F060/2/4/6 also have an external memory interface (EMIF) for accessing offchip data memory or memory-mapped peripherals. External data memory address space can be mapped to on-chip memory only, off-chip memory only, or a combination of the two (addresses up to 4 k directed to on-chip, above 4 k directed to EMIF). The EMIF is also configurable for multiplexed or non-multiplexed address/data lines. The MCU’s program memory consists of 64 k (C8051F060/1/2/3/4/5) or 32 k (C8051F066/7) of Flash. This memory may be reprogrammed in-system in 512 byte sectors, and requires no special off-chip programming voltage. On the C8051F060/1/2/3/4/5, the 1024 bytes from addresses 0xFC00 to 0xFFFF are reserved. There is also a single 128 byte Scratchpad Memory sector on all devices which may be used by firmware for non-volatile data storage. See Figure 1.7 for the MCU system memory map. Figure 1.7. On-Chip Memory Map Rev. 1.327 C8051F060/1/2/3/4/5/6/7 1.3. JTAG Debug and Boundary Scan The C8051F06x family has on-chip JTAG boundary scan and debug circuitry that provides non-intrusive, full speed, in-circuit debugging using the production part installed in the end application, via the four-pin JTAG interface. The JTAG port is fully compliant to IEEE 1149.1, providing full boundary scan for test and manufacturing purposes. Silicon Laboratories' debugging system supports inspection and modification of memory and registers, breakpoints, watchpoints, a stack monitor, and single stepping. No additional target RAM, program memory, timers, or communications channels are required. All the digital and analog peripherals are functional and work correctly while debugging. All the peripherals (except for the ADCs and SMBus) are stalled when the MCU is halted, during single stepping, or at a breakpoint in order to keep them synchronized with instruction execution. The C8051F060DK development kit provides all the hardware and software necessary to develop application code and perform in-circuit debugging with the C8051F06x MCUs. The kit includes a Windows (95 or later) development environment, a serial adapter for connecting to the JTAG port, and a target application board with a C8051F060 MCU installed. All of the necessary communication cables and a wall-mount power supply are also supplied with the development kit. Silicon Labs’ debug environment is a vastly superior configuration for developing and debugging embedded applications compared to standard MCU emulators, which use on-board "ICE Chips" and target cables and require the MCU in the application board to be socketed. Silicon Labs' debug environment both increases ease of use and preserves the performance of the precision, on-chip analog peripherals. Figure 1.8. Development/In-System Debug Diagram 28 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1.4. Programmable Digital I/O and Crossbar Three standard 8051 Ports (0, 1, and 2) are available on the MCUs. The C8051F060/2/4/6 have 4 additional 8-bit ports (3, 5, 6, and 7), and a 3-bit port (port 4) for a total of 59 general-purpose I/O Pins. The Ports behave like the standard 8051 with a few enhancements. Each port pin can be configured as either a push-pull or open-drain output. Also, the "weak pull-ups" which are normally fixed on an 8051 can be globally disabled, providing additional power saving capabilities for low-power applications. Perhaps the most unique enhancement is the Digital Crossbar. This is a large digital switching network that allows mapping of internal digital system resources to Port I/O pins on P0, P1, P2, and P3. (See Figure 1.9) Unlike microcontrollers with standard multiplexed digital I/O ports, all combinations of functions are supported with all package options offered. The on-chip counter/timers, serial buses, HW interrupts, comparator outputs, and other digital signals in the controller can be configured to appear on the Port I/O pins specified in the Crossbar Control registers. This allows the user to select the exact mix of general purpose Port I/O and digital resources needed for the particular application. Figure 1.9. Digital Crossbar Diagram Rev. 1.329 C8051F060/1/2/3/4/5/6/7 1.5. Programmable Counter Array The C8051F06x MCU family includes an on-board Programmable Counter/Timer Array (PCA) in addition to the five 16-bit general purpose counter/timers. The PCA consists of a dedicated 16-bit counter/timer time base with 6 programmable capture/compare modules. The timebase is clocked from one of six sources: the system clock divided by 12, the system clock divided by 4, Timer 0 overflow, an External Clock Input (ECI pin), the system clock, or the external oscillator source divided by 8. Each capture/compare module can be configured to operate in one of six modes: Edge-Triggered Capture, Software Timer, High Speed Output, Frequency Output, 8-Bit Pulse Width Modulator, or 16-Bit Pulse Width Modulator. The PCA Capture/Compare Module I/O and External Clock Input are routed to the MCU Port I/ O via the Digital Crossbar. Figure 1.10. PCA Block Diagram 30 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1.6. Controller Area Network The C8051F060/1/2/3 devices feature a Controller Area Network (CAN) controller that implements serial communication using the CAN protocol. The CAN controller facilitates communication on a CAN network in accordance with the Bosch specification 2.0A (basic CAN) and 2.0B (full CAN). The CAN controller consists of a CAN Core, Message RAM (separate from the C8051 RAM), a message handler state machine, and control registers. The CAN controller can operate at bit rates up to 1 Mbit/second. Silicon Labs CAN has 32 message objects each having its own identifier mask used for acceptance filtering of received messages. Incoming data, message objects and identifier masks are stored in the CAN message RAM. All protocol functions for transmission of data and acceptance filtering is performed by the CAN controller and not by the C8051 MCU. In this way, minimal CPU bandwidth is used for CAN communication. The C8051 configures the CAN controller, accesses received data, and passes data for transmission via Special Function Registers (SFR) in the C8051. Figure 1.11. CAN Controller Overview Rev. 1.331 C8051F060/1/2/3/4/5/6/7 1.7. Serial Ports The C8051F06x MCU Family includes two Enhanced Full-Duplex UARTs, an enhanced SPI Bus, and SMBus/I2C. Each of the serial buses is fully implemented in hardware and makes extensive use of the CIP-51's interrupts, thus requiring very little intervention by the CPU. The serial buses do not "share" resources such as timers, interrupts, or Port I/O, so any or all of the serial buses may be used together with any other. 32 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1.8. 16-Bit Analog to Digital Converters The C8051F060/1/2/3/4/5/6/7 devices have two on-chip 16-bit SAR ADCs (ADC0 and ADC1), which can be used independently in single-ended mode, or together in differential mode. ADC0 and ADC1 can directly access on-chip or external RAM, using the DMA interface. With a maximum throughput of 1 Msps, the ADCs offer 16 bit performance with two available linearity grades. ADC0 and ADC1 each have the capability to use dedicated, on-chip voltage reference circuitry or an external voltage reference source. The ADCs are under full control of the CIP-51 microcontroller via the associated Special Function Registers. The system controller can also put the ADCs into shutdown mode to save power. Conversions can be started in four ways; a software command, an overflow of Timer 2, an overflow of Timer 3, or an external signal input. This flexibility allows the start of conversion to be triggered by software events, external HW signals, or a periodic timer overflow signal. The two ADCs can operate independently, or be synchronized to perform conversions at the same time. Conversion completions are indicated by status bits, and can generate interrupts. The resulting 16-bit data words are latched into SFRs upon completion of a conversion. A DMA interface is also provided, which can gather conversions from the ADCs, and directly store them to on-chip or external RAM. ADC0 also contains Window Compare registers, which can be configured to interrupt the controller when ADC0 data is within or outside of a specified range. ADC0 can monitor a key voltage continuously in background mode, and not interrupt the controller unless the converted data is within the specified window. Rev. 1.333 C8051F060/1/2/3/4/5/6/7 Figure 1.12. 16-Bit ADC Block Diagram 34 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1.9. 10-Bit Analog to Digital Converter The C8051F060/1/2/3 devices have an on-board 10-bit SAR ADC (ADC2) with a 9-channel input multiplexer and programmable gain amplifier. This ADC features a 200 ksps maximum throughput and true 10bit performance with an INL of ±1LSB. Eight input pins are available for measurement and can be programmed as single-ended or differential inputs. Additionally, the on-chip temperature sensor can be used as an input to the ADC. The ADC is under full control of the CIP-51 microcontroller via the Special Function Registers. The ADC2 voltage reference is selected between the analog power supply (AV+) and the external VREF2 pin. User software may put ADC2 into shutdown mode to save power. A flexible conversion scheduling system allows ADC2 conversions to be initiated by software commands, timer overflows, or an external input signal. Conversion completions are indicated by a status bit and an interrupt (if enabled), and the resulting 10-bit data word is latched into two SFR locations upon completion. ADC2 also contains Window Compare registers, which can be configured to interrupt the controller when ADC2 data is within or outside of a specified range. ADC2 can monitor a key voltage continuously in background mode, and not interrupt the controller unless the converted data is within the specified window. Figure 1.13. 10-Bit ADC Diagram Rev. 1.335 C8051F060/1/2/3/4/5/6/7 1.10. 12-bit Digital to Analog Converters The C8051F060/1/2/3 MCUs have two integrated 12-bit Digital to Analog Converters (DACs). The MCU data and control interface to each DAC is via the Special Function Registers. The MCU can place either or both of the DACs in a low power shutdown mode. The DACs are voltage output mode and include a flexible output scheduling mechanism. This scheduling mechanism allows DAC output updates to be forced by a software write or scheduled on a Timer 2, 3, or 4 overflow. The DAC voltage reference is supplied from the dedicated VREFD input pin on C8051F060/2 devices or via the VREF2 pin on C8051F061/3 devices, which is shared with ADC2. The DACs are especially useful as references for the comparators or offsets for the differential inputs of the ADCs. Figure 1.14. DAC System Block Diagram 36 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 1.11. Analog Comparators The C8051F060/1/2/3/4/5/6/7 MCUs include three analog comparators on-chip. The comparators have software programmable hysteresis and response time. Each comparator can generate an interrupt on its rising edge, falling edge, or both. The interrupts are capable of waking up the MCU from sleep mode, and Comparator 0 can be used as a reset source. The output state of the comparators can be polled in software or routed to Port I/O pins via the Crossbar. Outputs from the comparator can be routed through the crossbar. The comparators can be programmed to a low power shutdown mode when not in use. Figure 1.15. Comparator Block Diagram Rev. 1.337 C8051F060/1/2/3/4/5/6/7 2. Absolute Maximum Ratings Table 2.1. Absolute Maximum Ratings* Parameter Conditions Min Typ Max Units Ambient temperature under bias -55 125 °C Storage Temperature -65 150 °C Voltage on any pin (except VDD, AV+, AVDD, and Port 0) with respect to DGND -0.3 VDD + 0.3 V Voltage on any Port 0 Pin with respect to DGND. -0.3 5.8 V Voltage on VDD, AV+, or AVDD with respect to DGND -0.3 4.2 V Maximum Total current through VDD, AV+, AVDD, DGND, and AGND 800 mA Maximum output current sunk by any Port pin 100 mA Maximum output current sunk by any other I/O pin 50 mA Maximum output current sourced by any Port pin 100 mA Maximum output current sourced by any other I/O pin 50 mA * Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the devices at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. 38 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 3. Global DC Electrical Characteristics Table 3.1. Global DC Electrical Characteristics -40 to +85 °C, 25 MHz System Clock unless otherwise specified. Parameter Analog Supply Voltage (AV+, AVDD) Conditions (Note 1) Digital Supply Voltage (VDD) Min Typ Max Units 2.7 3.0 3.6 V 2.7 3.0 3.6 V 0.5 V Analog-to-Digital Supply Delta (|VDD - AV+| or |VDD - AVDD|) Supply Current from Analog Peripherals (active) Internal REF, ADC, DAC, Comparators all enabled. (Note 2) 14 mA Supply Current from Analog Peripherals (inactive) Internal REF, ADC, DAC, Comparators all disabled, oscillator disabled. 0.2 μA Supply Current from CPU and VDD=2.7 V, Clock=25 MHz Digital Peripherals (CPU active) VDD=2.7 V, Clock=1 MHz (Note 3) VDD=2.7 V, Clock=32 kHz VDD=3.0 V, Clock=25 MHz VDD=3.0 V, Clock=1 MHz VDD=3.0 V, Clock=32 kHz 18 0.7 30 20 1.0 35 mA mA μA mA mA μA VDD=2.7 V, Clock=25 MHz VDD=2.7 V, Clock=1 MHz VDD=2.7 V, Clock=32 kHz VDD=3.0 V, Clock=25 MHz VDD=3.0 V, Clock=1 MHz VDD=3.0 V, Clock=32 kHz 13 0.5 20 16 0.8 23 mA mA μA mA mA μA Supply Current with all systems Oscillator not running shut down 0.2 μA VDD Supply RAM Data Retention Voltage 1.5 V Supply Current from CPU and Digital Peripherals (CPU inactive, not accessing Flash) (Note 3) SYSCLK (System Clock) (Note 4) Specified Operating Temperature Range 0 25 MHz -40 +85 °C Note 1: Analog Supply AV+ must be greater than 1 V for VDD monitor to operate. Note 2: Internal Oscillator and VDD Monitor current not included. Individual supply current contributions for each peripheral are listed in the chapter. Note 3: Current increases linearly with supply Voltage. Note 4: SYSCLK must be at least 32 kHz to enable debugging. Rev. 1.339 C8051F060/1/2/3/4/5/6/7 4. Pinout and Package Definitions Table 4.1. Pin Definitions Pin Numbers Name F061 F064 F065 F062 F063 F066 F067 Type Description VDD 37, 64, 26, 40, 37, 64, 26, 40, 90 55 90 55 Digital Supply Voltage. Must be tied to +2.7 to +3.6 V. DGND 38, 63, 27, 39, 38, 63, 27, 39, 89 54 89 54 Digital Ground. Must be tied to Ground. AV+ 11, 16, 7, 10, 11, 16, 7, 10, 24 18 24 18 Analog Supply Voltage. Must be tied to +2.7 to +3.6 V. AVDD AGND 40 F060 13 23 13 23 Analog Supply Voltage. Must be tied to +2.7 to +3.6 V. 10, 14, 6, 11, 10, 14, 6, 11, 17, 23 19, 22 17, 23 19, 22 Analog Ground. Must be tied to Ground. TMS 96 52 96 52 D In JTAG Test Mode Select with internal pull-up. TCK 97 53 97 53 D In JTAG Test Clock with internal pull-up. TDI 98 56 98 56 D In JTAG Test Data Input with internal pull-up. TDI is latched on the rising edge of TCK. TDO 99 57 99 57 D Out JTAG Test Data Output with internal pull-up. Data is shifted out on TDO on the falling edge of TCK. TDO output is a tri-state driver. /RST 100 58 100 58 D I/O Device Reset. Open-drain output of internal VDD monitor. Is driven low when VDD is 0x1000. Given: AMX0SL = 0x00, ADC0LTH:ADC0LTL = 0x1000, ADC0GTH:ADC0GTL = 0x2000. An ADC0 End of Conversion will cause an ADC0 Window Compare Interrupt (AD0WINT = ‘1’) if the resulting ADC0 Data Word is > 0x2000 or < 0x1000. Rev. 1.3 71 C8051F060/1/2/3/4/5/6/7 Figure 5.29. 16-Bit ADC0 Window Interrupt Example: Differential Data Given: AMX0SL = 0x40, ADC0LTH:ADC0LTL = 0x1000, ADC0GTH:ADC0GTL = 0xFFFF. An ADC0 End of Conversion will cause an ADC0 Window Compare Interrupt (AD0WINT = ‘1’) if the resulting ADC0 Data Word is < 0x1000 and > 0xFFFF. (In two’s-complement math, 0xFFFF = -1.) 72 Given: AMX0SL = 0x40, ADC0LTH:ADC0LTL = 0xFFFF, ADC0GTH:ADC0GTL = 0x1000. An ADC0 End of Conversion will cause an ADC0 Window Compare Interrupt (AD0WINT = ‘1’) if the resulting ADC0 Data Word is < 0xFFFF or > 0x1000. (In two’s-complement math, 0xFFFF = -1.) Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Table 5.2. 16-Bit ADC0 and ADC1 Electrical Characteristics VDD = 3.0 V, AV+ = 3.0 V, AVDD = 3.0 V, VREF = 2.50 V (REFBE=0), -40 to +85 °C unless otherwise specified Parameter Conditions Min Typ Max Units DC Accuracy Resolution 16 bits Integral Nonlinearity (C8051F060/1/4/5/6/7) Single-Ended Differential ±0.75 ±0.5 ±2 ±1 LSB Integral Nonlinearity (C8051F062/3) Single-Ended Differential ±1.5 ±1 ±4 ±2 LSB Differential Nonlinearity Guaranteed Monotonic ±0.5 LSB 0.1 mV 0.008 %F.S. 0.5 ppm/°C Signal-to-Noise Plus Distortion Fin = 10 kHz, Single-Ended Fin = 100 kHz, Single-Ended Fin = 10 kHz, Differential Fin = 100 kHz, Differential 86 84 89 88 dB dB dB dB Total Harmonic Distortion Fin = 10 kHz, Single-Ended Fin = 100 kHz, Single-Ended Fin = 10 kHz, Differential Fin = 100 kHz, Differential 96 84 103 93 dB dB dB dB Spurious-Free Dynamic Range Fin = 10 kHz, Single-Ended Fin = 100 kHz, Single-Ended Fin = 10 kHz, Differential Fin = 100 kHz, Differential 97 88 104 99 dB dB dB dB CMRR 86 dB 100 dB Offset Error Full Scale Error Gain Temperature Coefficient Dynamic Performance (Sampling Rate = 1 Msps, AVDD, AV+ = 3.3V) Fin = 10 kHz Channel Isolation Timing SAR Clock Frequency 25 MHz Conversion Time in SAR Clocks 18 clocks Track/Hold Acquisition Time 280 ns Throughput Rate 1 Msps Aperture Delay External CNVST Signal 1.5 ns RMS Aperture Jitter External CNVST Signal 5 ps Analog Inputs Input Voltage Range Single-Ended (AINn - AINnG) Differential (AIN0 - AIN1) Input Capacitance 0 -VREF VREF VREF 80 Rev. 1.3 V V pF 73 C8051F060/1/2/3/4/5/6/7 Table 5.2. 16-Bit ADC0 and ADC1 Electrical Characteristics (Continued) VDD = 3.0 V, AV+ = 3.0 V, AVDD = 3.0 V, VREF = 2.50 V (REFBE=0), -40 to +85 °C unless otherwise specified Parameter Conditions Min Operating Input Range AIN0 or AIN1 AIN0G or AIN1G (DC Only) Typ Max -0.2 -0.2 AV+ 0.6 Units V V Power Specifications Power Supply Current (each ADC) Operating Mode, 1 Msps AV+ AVDD Shutdown Mode 4.0 2.0 0x0080). Figure 7.16 shows an example using left-justified data with the same comparison values. Figure 7.15. ADC Window Compare Example: Right-Justified Single-Ended Data Figure 7.16. ADC Window Compare Example: Left-Justified Single-Ended Data Rev. 1.3 99 C8051F060/1/2/3/4/5/6/7 7.3.2. Window Detector In Differential Mode Figure 7.17 shows two example window comparisons for right-justified, differential data, with ADC2LTH:ADC2LTL = 0x0040 (+64d) and ADC2GTH:ADC2GTH = 0xFFFF (-1d). In differential mode, the measurable voltage between the input pins is between -VREF and VREF*(511/512). Output codes are represented as 10-bit 2’s complement signed integers. In the left example, an AD2WINT interrupt will be generated if the ADC2 conversion word (ADC2H:ADC2L) is within the range defined by ADC2GTH:ADC2GTL and ADC2LTH:ADC2LTL (if 0xFFFF (-1d) < ADC2H:ADC2L < 0x0040 (64d)). In the right example, an AD2WINT interrupt will be generated if the ADC2 conversion word is outside of the range defined by the ADC2GT and ADC2LT registers (if ADC2H:ADC2L < 0xFFFF (-1d) or ADC2H:ADC2L > 0x0040 (+64d)). Figure 7.18 shows an example using left-justified data with the same comparison values. Figure 7.17. ADC Window Compare Example: Right-Justified Differential Data Figure 7.18. ADC Window Compare Example: Left-Justified Differential Data 100 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Table 7.1. ADC2 Electrical Characteristics VDD = 3.0 V, VREF = 2.40 V (REFSL=0), PGA Gain = 1, -40°C to +85°C unless otherwise specified Parameter Conditions Min Typ Max Units DC Accuracy Resolution 10 Integral Nonlinearity Differential Nonlinearity Full Scale Error ±0.5 ±1 LSB ±0.5 ±1 LSB -12 1 12 LSB -15 -5 5 LSB Guaranteed Monotonic Offset Error Differential mode bits Offset Temperature Coefficient 3.6 ppm/°C DYNAMIC PERFORMANCE (10 kHz sine-wave Differential input, 1 dB below Full Scale, 200 ksps) Signal-to-Noise Plus Distortion Total Harmonic Distortion 53 Up to the 5th harmonic Spurious-Free Dynamic Range 55.5 dB -67 dB 78 dB Conversion Rate SAR Conversion Clock 3 MHz Conversion Time in SAR Clocks 10 clocks Track/Hold Acquisition Time 300 ns Throughput Rate 200 ksps 0 -VREF VREF VREF V V 0 AV+ V Analog Inputs ADC Input Voltage Range Single Ended (AIN+ - AGND) Differential (AIN+ - AIN-) Absolute Pin Voltage with respect Single Ended or Differential to AGND Input Capacitance 5 pF ±0.2 °C Temperature Sensor Linearity Offset Temp = 0 °C 776 mV Offset Error (Note 1) Temp = 0 °C ±8.9 mV Slope 2.89 mV/°C Slope Error (Note 1) ±63 μV/°C Power Specifications Power Supply Current (VDD sup- Operating Mode, 200 ksps plied to ADC2) 400 Power Supply Rejection ±0.3 900 μA mV/V Note 1: Represents one standard deviation from the mean value. Rev. 1.3 101 C8051F060/1/2/3/4/5/6/7 102 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 8. DACs, 12-Bit Voltage Mode (DAC0 and DAC1, C8051F060/1/2/3) The C8051F060/1/2/3 devices include two on-chip 12-bit voltage-mode Digital-to-Analog Converters (DACs). Each DAC has an output swing of 0 V to (VREF-1LSB) for a corresponding input code range of 0x000 to 0xFFF. The DACs may be enabled/disabled via their corresponding control registers, DAC0CN and DAC1CN. While disabled, the DAC output is maintained in a high-impedance state, and the DAC supply current falls to 1 μA or less. The voltage reference for each DAC is supplied at the VREFD pin (C8051F060/2 devices) or the VREF2 pin (C8051F061/3 devices). See Section “9. Voltage Reference 2 (C8051F060/2)” on page 111 or Section “10. Voltage Reference 2 (C8051F061/3)” on page 113 for more information on configuring the voltage reference for the DACs. Note that the BIASE bit described in the voltage reference sections must be set to ‘1’ to use the DACs. Figure 8.1. DAC Functional Block Diagram Rev. 1.3 103 C8051F060/1/2/3/4/5/6/7 8.1. DAC Output Scheduling Each DAC features a flexible output update mechanism which allows for seamless full-scale changes and supports jitter-free updates for waveform generation. The following examples are written in terms of DAC0, but DAC1 operation is identical. 8.1.1. Update Output On-Demand In its default mode (DAC0CN.[4:3] = ‘00’) the DAC0 output is updated “on-demand” on a write to the highbyte of the DAC0 data register (DAC0H). It is important to note that writes to DAC0L are held, and have no effect on the DAC0 output until a write to DAC0H takes place. If writing a full 12-bit word to the DAC data registers, the 12-bit data word is written to the low byte (DAC0L) and high byte (DAC0H) data registers. Data is latched into DAC0 after a write to the corresponding DAC0H register, so the write sequence should be DAC0L followed by DAC0H if the full 12-bit resolution is required. The DAC can be used in 8bit mode by initializing DAC0L to the desired value (typically 0x00), and writing data to only DAC0H (also see Section 8.2 for information on formatting the 12-bit DAC data word within the 16-bit SFR space). 8.1.2. Update Output Based on Timer Overflow Similar to the ADC operation, in which an ADC conversion can be initiated by a timer overflow independently of the processor, the DAC outputs can use a Timer overflow to schedule an output update event. This feature is useful in systems where the DAC is used to generate a waveform of a defined sampling rate by eliminating the effects of variable interrupt latency and instruction execution on the timing of the DAC output. When the DAC0MD bits (DAC0CN.[4:3]) are set to ‘01’, ‘10’, or ‘11’, writes to both DAC data registers (DAC0L and DAC0H) are held until an associated Timer overflow event (Timer 3, Timer 4, or Timer 2, respectively) occurs, at which time the DAC0H:DAC0L contents are copied to the DAC input latches allowing the DAC output to change to the new value. 8.2. DAC Output Scaling/Justification In some instances, input data should be shifted prior to a DAC0 write operation to properly justify data within the DAC input registers. This action would typically require one or more load and shift operations, adding software overhead and slowing DAC throughput. To alleviate this problem, the data-formatting feature provides a means for the user to program the orientation of the DAC0 data word within data registers DAC0H and DAC0L. The three DAC0DF bits (DAC0CN.[2:0]) allow the user to specify one of five data word orientations as shown in the DAC0CN register definition. DAC1 is functionally the same as DAC0 described above. The electrical specifications for both DAC0 and DAC1 are given in Table 8.1. 104 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 8.2. DAC0H: DAC0 High Byte Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0xD3 SFR Page: 0 DAC0 Data Word Most Significant Byte. Figure 8.3. DAC0L: DAC0 Low Byte Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0xD2 SFR Page: 0 DAC0 Data Word Least Significant Byte. Rev. 1.3 105 C8051F060/1/2/3/4/5/6/7 Figure 8.4. DAC0CN: DAC0 Control Register R/W R/W R/W DAC0EN - - Bit7 Bit6 Bit5 Bit7: Bits6-5: Bits4-3: Bits2-0: R/W R/W R/W R/W DAC0MD1 DAC0MD0 DAC0DF2 DAC0DF1 Bit4 Bit3 Bit2 Bit1 R/W Reset Value DAC0DF0 00000000 Bit0 SFR Address: 0xD4 SFR Page: 0 DAC0EN: DAC0 Enable Bit. 0: DAC0 Disabled. DAC0 Output pin is disabled; DAC0 is in low-power shutdown mode. 1: DAC0 Enabled. DAC0 Output pin is active; DAC0 is operational. UNUSED. Read = 00b; Write = don’t care. DAC0MD1-0: DAC0 Mode Bits. 00: DAC output updates occur on a write to DAC0H. 01: DAC output updates occur on Timer 3 overflow. 10: DAC output updates occur on Timer 4 overflow. 11: DAC output updates occur on Timer 2 overflow. DAC0DF2-0: DAC0 Data Format Bits: 000: The most significant nibble of the DAC0 Data Word is in DAC0H[3:0], while the least significant byte is in DAC0L. DAC0H DAC0L MSB 001: LSB The most significant 5-bits of the DAC0 Data Word is in DAC0H[4:0], while the least significant 7-bits are in DAC0L[7:1]. DAC0H DAC0L MSB 010: LSB The most significant 6-bits of the DAC0 Data Word is in DAC0H[5:0], while the least significant 6-bits are in DAC0L[7:2]. DAC0H DAC0L MSB 011: LSB The most significant 7-bits of the DAC0 Data Word is in DAC0H[6:0], while the least significant 5-bits are in DAC0L[7:3]. DAC0H DAC0L MSB 1xx: LSB The most significant 8-bits of the DAC0 Data Word is in DAC0H[7:0], while the least significant 4-bits are in DAC0L[7:4]. DAC0H DAC0L MSB 106 LSB Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 8.5. DAC1H: DAC1 High Byte Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0xD3 SFR Page: 1 DAC1 Data Word Most Significant Byte. Figure 8.6. DAC1L: DAC1 Low Byte Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0xD2 SFR Page: 1 DAC1 Data Word Least Significant Byte. Rev. 1.3 107 C8051F060/1/2/3/4/5/6/7 Figure 8.7. DAC1CN: DAC1 Control Register R/W R/W R/W DAC1EN - - Bit7 Bit6 Bit5 Bit7: Bits6-5: Bits4-3: Bits2-0: R/W R/W R/W R/W DAC1MD1 DAC1MD0 DAC1DF2 DAC1DF1 Bit4 Bit3 Bit2 Bit1 R/W Reset Value DAC1DF0 00000000 Bit0 SFR Address: 0xD4 SFR Page: 1 DAC1EN: DAC1 Enable Bit. 0: DAC1 Disabled. DAC1 Output pin is disabled; DAC1 is in low-power shutdown mode. 1: DAC1 Enabled. DAC1 Output pin is active; DAC1 is operational. UNUSED. Read = 00b; Write = don’t care. DAC1MD1-0: DAC1 Mode Bits: 00: DAC output updates occur on a write to DAC1H. 01: DAC output updates occur on Timer 3 overflow. 10: DAC output updates occur on Timer 4 overflow. 11: DAC output updates occur on Timer 2 overflow. DAC1DF2: DAC1 Data Format Bits: 000: The most significant nibble of the DAC1 Data Word is in DAC1H[3:0], while the least significant byte is in DAC1L. DAC1H DAC1L MSB 001: LSB The most significant 5-bits of the DAC1 Data Word is in DAC1H[4:0], while the least significant 7-bits are in DAC1L[7:1]. DAC1H DAC1L MSB 010: LSB The most significant 6-bits of the DAC1 Data Word is in DAC1H[5:0], while the least significant 6-bits are in DAC1L[7:2]. DAC1H DAC1L MSB 011: LSB The most significant 7-bits of the DAC1 Data Word is in DAC1H[6:0], while the least significant 5-bits are in DAC1L[7:3]. DAC1H DAC1L MSB 1xx: LSB The most significant 8-bits of the DAC1 Data Word is in DAC1H[7:0], while the least significant 4-bits are in DAC1L[7:4]. DAC1H DAC1L MSB 108 LSB Rev. 1.3 C8051F060/1/2/3/4/5/6/7 . Table 8.1. DAC Electrical Characteristics VDD = 3.0 V, AV+ = 3.0 V, VREF = 2.40 V (REFBE = 0), No Output Load unless otherwise specified Parameter Conditions Min Typ Max Units Static Performance Resolution Integral Nonlinearity 12 bits ±1.5 LSB Differential Nonlinearity ±1 Output Noise No Output Filter 100 kHz Output Filter 10 kHz Output Filter 250 128 41 Offset Error Data Word = 0x014 ±3 LSB μVrms ±30 mV Offset Tempco 6 Full-Scale Error ±20 Full-Scale Error Tempco 10 ppm/°C VDD Power Supply Rejection Ratio -60 dB Output Impedance in Shutdown DACnEN = 0 Mode 100 k Output Sink Current 300 μA 15 mA 0.44 V/μs 10 μs Output Short-Circuit Current Data Word = 0xFFF ppm/°C ±60 mV Dynamic Performance Voltage Output Slew Rate Load = 40pF Output Settling Time to 1/2 LSB Load = 40pF, Output swing from code 0xFFF to 0x014 Output Voltage Swing 0 Startup Time VREF1LSB V 10 μs 60 ppm Analog Outputs Load Regulation IL = 0.01mA to 0.3mA at code 0xFFF Power Consumption (each DAC) Power Supply Current (AV+ supplied to DAC) Data Word = 0x7FF 300 Rev. 1.3 500 μA 109 C8051F060/1/2/3/4/5/6/7 110 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 9. Voltage Reference 2 (C8051F060/2) The voltage reference circuitry offers full flexibility in operating the ADC2 and DAC modules. Two voltage reference input pins allow ADC2 and the two DACs to reference an external voltage reference or the onchip voltage reference output. ADC2 may also reference the analog power supply voltage, via the VREF multiplexer shown in Figure 9.1. The internal voltage reference circuit consists of a 1.2 V, temperature stable bandgap voltage reference generator and a gain-of-two output buffer amplifier. The internal reference may be routed via the VREF pin to external system components or to the voltage reference input pins shown in Figure 9.1. The maximum load seen by the VREF pin must be less than 200 μA to AGND. Bypass capacitors of 0.1 μF and 4.7 μF are recommended from the VREF pin to AGND, as shown in Figure 9.1. The Reference Control Register 2, REF2CN (defined in Figure 9.2) enables/disables the internal reference generator and selects the reference input for ADC2. The BIASE bit in REF2CN enables the on-board reference generator while the REFBE bit enables the gain-of-two buffer amplifier which drives the VREF pin. When disabled, the supply current drawn by the bandgap and buffer amplifier falls to less than 1 μA (typical) and the output of the buffer amplifier enters a high impedance state. If the internal bandgap is used as the reference voltage generator, BIASE and REFBE must both be set to logic 1. If the internal reference is not used, REFBE may be set to logic 0. Note that the BIASE bit must be set to logic 1 if ADC2 or either DAC is used, regardless of the voltage reference used. If neither ADC2 nor the DACs are being used, both of these bits can be set to logic 0 to conserve power. Bit AD2VRS selects between VREF2 and AV+ for the ADC2 voltage reference source. The electrical specifications for the Voltage Reference are given in Table 9.1. Figure 9.1. Voltage Reference Functional Block Diagram Rev. 1.3 111 C8051F060/1/2/3/4/5/6/7 The temperature sensor connects to the highest order input of the ADC2 input multiplexer (see Section “7. 10-Bit ADC (ADC2, C8051F060/1/2/3)” on page 87). The TEMPE bit within REF2CN enables and disables the temperature sensor. While disabled, the temperature sensor defaults to a high impedance state, and any A/D measurements performed on the sensor while disabled result in meaningless data. Figure 9.2. REF2CN: Reference Control Register 2 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - - - AD2VRS TEMPE BIASE REFBE 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-4: Bit3: Bit2: Bit1: Bit0: Bit0 SFR Address: 0xD1 SFR Page: 2 UNUSED. Read = 0000b; Write = don’t care. AD2VRS: ADC2 Voltage Reference Select. 0: ADC2 voltage reference from VREF2 pin. 1: ADC2 voltage reference from AV+. TEMPE: Temperature Sensor Enable Bit. 0: Internal Temperature Sensor Off. 1: Internal Temperature Sensor On. BIASE: ADC/DAC Bias Generator Enable Bit. (Must be ‘1’ if using ADC2 or DACs). 0: Internal Bias Generator Off. 1: Internal Bias Generator On. REFBE: Internal Reference Buffer Enable Bit. 0: Internal Reference Buffer Off. 1: Internal Reference Buffer On. Internal voltage reference is driven on the VREF pin. Table 9.1. Voltage Reference Electrical Characteristics VDD = 3.0 V, AV+ = 3.0 V, -40 to +85 °C unless otherwise specified Parameter Conditions Min Typ Max Units 2.36 2.43 2.48 V Internal Reference (REFBE = 1) Output Voltage 25 °C ambient VREF Power Supply Current 50 VREF Short-Circuit Current μA 30 VREF Temperature Coefficient mA 15 ppm/°C 0.5 ppm/μA Load Regulation Load = 0 to 200 μA to AGND VREF Turn-on Time 1 4.7 μF tantalum, 0.1 μF ceramic bypass 2 ms VREF Turn-on Time 2 0.1 μF ceramic bypass 20 μs VREF Turn-on Time 3 no bypass cap 10 μs External Reference (REFBE = 0) Input Voltage Range 1.00 Input Current 112 0 Rev. 1.3 (AV+) 0.3 V 1 μA C8051F060/1/2/3/4/5/6/7 10. Voltage Reference 2 (C8051F061/3) The internal voltage reference circuit consists of a 1.2 V, temperature stable bandgap voltage reference generator and a gain-of-two output buffer amplifier. The internal reference may be routed via the VREF pin to external system components or to the VREF2 input pin shown in Figure 10.1. The maximum load seen by the VREF pin must be less than 200 μA to AGND. Bypass capacitors of 0.1 μF and 4.7 μF are recommended from the VREF pin to AGND, as shown in Figure 10.1. The VREF2 pin provides a voltage reference input for ADC2 and the DACs. ADC2 may also reference the analog power supply voltage, via the VREF multiplexers shown in Figure 10.1. The Reference Control Register 2, REF2CN (defined in Figure 10.2) enables/disables the internal reference generator and selects the reference input for ADC2. The BIASE bit in REF2CN enables the on-board reference generator while the REFBE bit enables the gain-of-two buffer amplifier which drives the VREF pin. When disabled, the supply current drawn by the bandgap and buffer amplifier falls to less than 1 μA (typical) and the output of the buffer amplifier enters a high impedance state. If the internal bandgap is used as the reference voltage generator, BIASE and REFBE must both be set to logic 1. If the internal reference is not used, REFBE may be set to logic 0. Note that the BIASE bit must be set to logic 1 if ADC2 or either DAC is used, regardless of the voltage reference used. If neither ADC2 nor the DACs are being used, both of these bits can be set to logic 0 to conserve power. Bit AD2VRS selects between VREF2 and AV+ for the ADC2 voltage reference source. The electrical specifications for the Voltage Reference are given in Table 10.1. Figure 10.1. Voltage Reference Functional Block Diagram Rev. 1.3 113 C8051F060/1/2/3/4/5/6/7 The temperature sensor connects to the highest order input of the ADC2 input multiplexer (see Section “7. 10-Bit ADC (ADC2, C8051F060/1/2/3)” on page 87). The TEMPE bit within REF2CN enables and disables the temperature sensor. While disabled, the temperature sensor defaults to a high impedance state, and any A/D measurements performed on the sensor while disabled result in meaningless data. Figure 10.2. REF2CN: Reference Control Register 2 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - - - AD2VRS TEMPE BIASE REFBE 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-4: Bit3: Bit2: Bit1: Bit0: Bit0 SFR Address: 0xD1 SFR Page: 2 UNUSED. Read = 0000b; Write = don’t care. AD2VRS: ADC2 Voltage Reference Select. 0: ADC2 voltage reference from VREF2 pin. 1: ADC2 voltage reference from AV+. TEMPE: Temperature Sensor Enable Bit. 0: Internal Temperature Sensor Off. 1: Internal Temperature Sensor On. BIASE: ADC/DAC Bias Generator Enable Bit. (Must be ‘1’ if using ADC2 or DACs). 0: Internal Bias Generator Off. 1: Internal Bias Generator On. REFBE: Internal Reference Buffer Enable Bit. 0: Internal Reference Buffer Off. 1: Internal Reference Buffer On. Internal voltage reference is driven on the VREF pin. Table 10.1. Voltage Reference Electrical Characteristics VDD = 3.0 V, AV+ = 3.0 V, -40 to +85 °C unless otherwise specified Parameter Conditions Min Typ Max Units 2.36 2.43 2.48 V Internal Reference (REFBE = 1) Output Voltage 25 °C ambient VREF Power Supply Current 50 VREF Short-Circuit Current μA 30 VREF Temperature Coefficient mA 15 ppm/°C 0.5 ppm/μA Load Regulation Load = 0 to 200 μA to AGND VREF Turn-on Time 1 4.7 μF tantalum, 0.1 μF ceramic bypass 2 ms VREF Turn-on Time 2 0.1 μF ceramic bypass 20 μs VREF Turn-on Time 3 no bypass cap 10 μs External Reference (REFBE = 0) Input Voltage Range 1.00 Input Current 114 0 Rev. 1.3 (AV+) 0.3 V 1 μA C8051F060/1/2/3/4/5/6/7 11. Voltage Reference 2 (C8051F064/5/6/7) The internal voltage reference circuit consists of a 1.2 V, temperature stable bandgap voltage reference generator and a gain-of-two output buffer amplifier. The internal reference may be routed to the VREF pin as shown in Figure 11.1. The maximum load seen by the VREF pin must be less than 200 μA to AGND. Bypass capacitors of 0.1 μF and 4.7 μF are recommended from the VREF pin to AGND, as shown in Figure 11.1. The Reference Control Register 2, REF2CN (defined in Figure 11.2) enables/disables the internal reference generator. The BIASE bit in REF2CN enables the on-board reference generator while the REFBE bit enables the gain-of-two buffer amplifier which drives the VREF pin. When disabled, the supply current drawn by the bandgap and buffer amplifier falls to less than 1 μA (typical) and the output of the buffer amplifier enters a high impedance state. If the internal bandgap is used as the reference voltage generator, BIASE and REFBE must both be set to logic 1. If the internal reference is not used, REFBE may be set to logic 0. The electrical specifications for the Voltage Reference are given in Table 11.1. Figure 11.1. Voltage Reference Functional Block Diagram Rev. 1.3 115 C8051F060/1/2/3/4/5/6/7 Figure 11.2. REF2CN: Reference Control Register 2 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - - - 0 0 BIASE REFBE 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-4: Bits2-3: Bit1: Bit0: Bit0 SFR Address: 0xD1 SFR Page: 2 UNUSED. Read = 0000b; Write = don’t care. RESERVED. Must Write to 00b. BIASE: ADC/DAC Bias Generator Enable Bit. (Must be ‘1’ if using ADC2 or DACs). 0: Internal Bias Generator Off. 1: Internal Bias Generator On. REFBE: Internal Reference Buffer Enable Bit. 0: Internal Reference Buffer Off. 1: Internal Reference Buffer On. Internal voltage reference is driven on the VREF pin. Table 11.1. Voltage Reference Electrical Characteristics VDD = 3.0 V, AV+ = 3.0 V, -40 to +85 °C unless otherwise specified Parameter Conditions Min Typ Max Units 2.36 2.43 2.48 V Internal Reference (REFBE = 1) Output Voltage 25 °C ambient VREF Power Supply Current 50 VREF Short-Circuit Current μA 30 VREF Temperature Coefficient mA 15 ppm/°C 0.5 ppm/μA Load Regulation Load = 0 to 200 μA to AGND VREF Turn-on Time 1 4.7 μF tantalum, 0.1 μF ceramic bypass 2 ms VREF Turn-on Time 2 0.1 μF ceramic bypass 20 μs VREF Turn-on Time 3 no bypass cap 10 μs 116 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 12. Comparators C8051F06x family of devices include three on-chip programmable voltage comparators, shown in Figure 12.1. Each comparator offers programmable response time and hysteresis. When assigned to a Port pin, the Comparator output may be configured as open drain or push-pull, and Comparator inputs should be configured as analog inputs (see Section “18.1.5. Configuring Port 1 and 2 pins as Analog Inputs” on page 207). The Comparator may also be used as a reset source (see Section “14.5. Comparator0 Reset” on page 165). The output of a Comparator can be polled by software, used as an interrupt source, used as a reset source, and/or routed to a Port pin. Each comparator can be individually enabled and disabled (shutdown). When disabled, the Comparator output (if assigned to a Port I/O pin via the Crossbar) defaults to the logic low state, and its supply current falls to less than 1 μA. See Section “18.1.1. Crossbar Pin Assignment and Allocation” on page 205 for details on configuring the Comparator output via the digital Crossbar. The Figure 12.1. Comparator Functional Block Diagram Rev. 1.3 117 C8051F060/1/2/3/4/5/6/7 Comparator inputs can be externally driven from -0.25 V to (VDD) + 0.25 V without damage or upset. The complete electrical specifications for the Comparator are given in Table 12.1. The Comparator response time may be configured in software using the CPnMD1-0 bits in register CPTnMD (see Figure 12.4). Selecting a longer response time reduces the amount of power consumed by the comparator. See Table 12.1 for complete timing and current consumption specifications. Figure 12.2. Comparator Hysteresis Plot The hysteresis of the Comparator is software-programmable via its Comparator Control register (CPTnCN). The user can program both the amount of hysteresis voltage (referred to the input voltage) and the positive and negative-going symmetry of this hysteresis around the threshold voltage. The Comparator hysteresis is programmed using Bits3-0 in the Comparator Control Register CPTnCN (shown in Figure 12.3). The amount of negative hysteresis voltage is determined by the settings of the CPnHYN bits. As shown in Figure 12.2, the negative hysteresis can be programmed to three different settings, or negative hysteresis can be disabled. In a similar way, the amount of positive hysteresis is determined by the setting the CPnHYP bits. 118 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Comparator interrupts can be generated on either rising-edge and falling-edge output transitions. (For Interrupt enable and priority control, see Section “13.3. Interrupt Handler” on page 151). The rising and/or falling -edge interrupts are enabled using the comparator’s Rising/Falling Edge Interrupt Enable Bits (CPnRIE and CPnFIE) in their respective Comparator Mode Selection Register (CPTnMD), shown in Figure 12.4. These bits allow the user to control which edge (or both) will cause a comparator interrupt. However, the comparator interrupt must also be enabled in the Extended Interrupt Enable Register (EIE1). The CPnFIF flag is set to logic 1 upon a Comparator falling-edge interrupt, and the CPnRIF flag is set to logic 1 upon the Comparator rising-edge interrupt. Once set, these bits remain set until cleared by software. The output state of a Comparator can be obtained at any time by reading the CPnOUT bit. A Comparator is enabled by setting its respective CPnEN bit to logic 1, and is disabled by clearing this bit to logic 0.Upon enabling a comparator, the output of the comparator is not immediately valid. Before using a comparator as an interrupt or reset source, software should wait for a minimum of the specified “Power-up time” as specified in Table 12.1, “Comparator Electrical Characteristics,” on page 122. 12.1. Comparator Inputs The Port pins selected as comparator inputs should be configured as analog inputs in the Port 2 Input Configuration Register (for details on Port configuration, see Section “18.1.3. Configuring Port Pins as Digital Inputs” on page 207). The inputs for Comparator are on Port 2 as follows: Comparator Input Port PIN CP0 + P2.6 CP0 - P2.7 CP1 + P2.2 CP1 - P2.3 CP2 + P2.4 CP2 - P2.5 Rev. 1.3 119 C8051F060/1/2/3/4/5/6/7 Figure 12.3. CPTnCN: Comparator 0, 1, and 2 Control Register R/W R/W R/W R/W CPnEN CPnOUT CPnRIF CPnFIF Bit7 Bit6 Bit5 Bit4 R/W R/W R/W R/W CPnHYP1 CPnHYP0 CPnHYN1 CPnHYN0 Bit3 Bit2 Bit1 Bit0 Reset Value 00000000 Bit Addressable SFR Address: CPT0CN: 0x88; CPT1CN: 0x88; CPT2CN: 0x88 SFR Pages: CPT0CN: page 1; CPT1CN: page 2; CPT2CN: page 3 Bit7: Bit6: Bit5: Bit4: Bits3-2: Bits1-0: NOTE: 120 CPnEN: Comparator Enable Bit. (Please see note below.) 0: Comparator Disabled. 1: Comparator Enabled. CPnOUT: Comparator Output State Flag. 0: Voltage on CPn+ < CPn-. 1: Voltage on CPn+ > CPn-. CPnRIF: Comparator Rising-Edge Interrupt Flag. 0: No Comparator Rising Edge Interrupt has occurred since this flag was last cleared. 1: Comparator Rising Edge Interrupt has occurred. Must be cleared by software. CPnFIF: Comparator Falling-Edge Interrupt Flag. 0: No Comparator Falling-Edge Interrupt has occurred since this flag was last cleared. 1: Comparator Falling-Edge Interrupt has occurred. Must be cleared by software. CPnHYP1-0: Comparator Positive Hysteresis Control Bits. 00: Positive Hysteresis Disabled. 01: Positive Hysteresis = 5 mV. 10: Positive Hysteresis = 10 mV. 11: Positive Hysteresis = 20 mV. CPnHYN1-0: Comparator Negative Hysteresis Control Bits. 00: Negative Hysteresis Disabled. 01: Negative Hysteresis = 5 mV. 10: Negative Hysteresis = 10 mV. 11: Negative Hysteresis = 20 mV. Upon enabling a comparator, the output of the comparator is not immediately valid. Before using a comparator as an interrupt or reset source, software should wait for a minimum of the specified “Power-up time” as specified in Table 12.1, “Comparator Electrical Characteristics,” on page 122. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 12.4. CPTnMD: Comparator Mode Selection Register R/W R/W R/W R/W R R R/W R/W Reset Value - - CPnRIE CPnFIE - - CPnMD1 CPnMD0 00000010 Bit2 Bit1 Bit0 Bit7 Bit6 Bit5 Bit4 Bit3 SFR Address: CPT0MD: 0x89; CPT1MD: 0x89; CPT2MD: 0x89 SFR Page: CPT0MD: page 1; CPT1MD: page 2; CPT2MD: page 3 Bits7-6: Bit 5: Bit 4: Bits3-2: Bits1-0: UNUSED. Read = 00b, Write = don’t care. CPnRIE: Comparator Rising-Edge Interrupt Enable Bit. 0: Comparator rising-edge interrupt disabled. 1: Comparator rising-edge interrupt enabled. CPnFIE: Comparator Falling-Edge Interrupt Enable Bit. 0: Comparator falling-edge interrupt disabled. 1: Comparator falling-edge interrupt enabled. UNUSED. Read = 00b, Write = don’t care. CPnMD1-CPnMD0: Comparator Mode Select These bits select the response time for the Comparator. Mode 0 1 2 3 CPnMD1 CPnMD0 0 0 0 1 1 0 1 1 Notes Fastest Response Time Lowest Power Consumption Rev. 1.3 121 C8051F060/1/2/3/4/5/6/7 Table 12.1. Comparator Electrical Characteristics VDD = 3.0 V, -40 to +85 °C unless otherwise specified. Parameter Conditions Min Response Time, Mode 0 CPn+ - CPn- = 100 mV 100 ns CPn+ - CPn- = 10 mV 250 ns Response Time, Mode 1 CPn+ - CPn- = 100 mV 175 ns CPn+ - CPn- = 10 mV 500 ns Response Time, Mode 2 CPn+ - CPn- = 100 mV 320 ns CPn+ - CPn- = 10 mV 1100 ns Response Time, Mode 3 CPn+ - CPn- = 100 mV 1050 ns CPn+ - CPn- = 10 mV 5200 ns Common-Mode Rejection Ratio Typ Max Units 1.5 4 mV/V 0 1 mV Positive Hysteresis 1 CPnHYP1-0 = 00 Positive Hysteresis 2 CPnHYP1-0 = 01 3 5 7 mV Positive Hysteresis 3 CPnHYP1-0 = 10 7 10 15 mV Positive Hysteresis 4 CPnHYP1-0 = 11 15 20 25 mV Negative Hysteresis 1 CPnHYN1-0 = 00 0 1 mV Negative Hysteresis 2 CPnHYN1-0 = 01 3 5 7 mV Negative Hysteresis 3 CPnHYN1-0 = 10 7 10 15 mV Negative Hysteresis 4 CPnHYN1-0 = 11 15 20 25 mV VDD + 0.25 V Inverting or Non-Inverting Input Voltage Range -0.25 Input Capacitance 7 Input Bias Current -5 Input Offset Voltage -5 0.001 pF +5 nA +5 mV 1 mV/V Power Supply Power Supply Rejection 0.1 Power-up Time 10 μs Mode 0 7.6 μA Mode 1 3.2 μA Mode 2 1.3 μA Mode 3 0.4 μA Supply Current at DC 122 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 13. CIP-51 Microcontroller The MCU system controller core is the CIP-51 microcontroller. The CIP-51 is fully compatible with the MCS-51™ instruction set; standard 803x/805x assemblers and compilers can be used to develop software. The MCU family has a superset of all the peripherals included with a standard 8051. Included are five 16-bit counter/timers (see description in Section 24), two full-duplex UARTs (see description in Section 22 and Section 23), 256 bytes of internal RAM, 128 byte Special Function Register (SFR) address space (see Section 13.2.6), and 59/24 General-Purpose I/O Pins (see description in Section 18). The CIP-51 also includes on-chip debug hardware (see description in Section 26), and interfaces directly with the MCU’s analog and digital subsystems providing a complete data acquisition or control-system solution in a single integrated circuit. - Fully Compatible with MCS-51 Instruction Set 25 MIPS Peak Throughput with 25 MHz Clock 0 to 25 MHz Clock Frequency 256 Bytes of Internal RAM 59/24 General-Purpose I/O Pins - Extended Interrupt Handler Reset Input Power Management Modes On-chip Debug Logic Program and Data Memory Security Rev. 1.3 123 C8051F060/1/2/3/4/5/6/7 The CIP-51 Microcontroller core implements the standard 8051 organization and peripherals as well as additional custom peripherals and functions to extend its capability (see Figure 13.1 for a block diagram). The CIP-51 includes the following features: Performance The CIP-51 employs a pipelined architecture that greatly increases its instruction throughput over the standard 8051 architecture. In a standard 8051, all instructions except for MUL and DIV take 12 or 24 system clock cycles to execute, and usually have a maximum system clock of 12 MHz. By contrast, the CIP-51 core executes 70% of its instructions in one or two system clock cycles, with no instructions taking more than eight system clock cycles. With the CIP-51's maximum system clock at 25 MHz, it has a peak throughput of 25 MIPS. The CIP-51 has a total of 109 instructions. The table below shows the total number of instructions that require each execution time. Clocks to Execute 1 2 2/3 3 3/4 4 4/5 5 8 Number of Instructions 26 50 5 14 7 3 1 2 1 Figure 13.1. CIP-51 Block Diagram 124 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Programming and Debugging Support A JTAG-based serial interface is provided for in-system programming of the Flash program memory and communication with on-chip debug support logic. The re-programmable Flash can also be read and changed a single byte at a time by the application software using the MOVC and MOVX instructions. This feature allows program memory to be used for non-volatile data storage as well as updating program code under software control. The on-chip debug support logic facilitates full speed in-circuit debugging, allowing the setting of hardware breakpoints and watch points, starting, stopping and single stepping through program execution (including interrupt service routines), examination of the program's call stack, and reading/writing the contents of registers and memory. This method of on-chip debug is completely non-intrusive and non-invasive, requiring no RAM, Stack, timers, or other on-chip resources. The CIP-51 is supported by development tools from Silicon Labs and third party vendors. Silicon Labs provides an integrated development environment (IDE) which interfaces to the CIP-51 via its JTAG port to provide fast and efficient in-system device programming and debugging. Third party macro assemblers and C compilers are also available. 13.1. Instruction Set The instruction set of the CIP-51 System Controller is fully compatible with the standard MCS-51™ instruction set; standard 8051 development tools can be used to develop software for the CIP-51. All CIP-51 instructions are the binary and functional equivalent of their MCS-51™ counterparts, including opcodes, addressing modes and effect on PSW flags. However, instruction timing is different than that of the standard 8051. 13.1.1. Instruction and CPU Timing In many 8051 implementations, a distinction is made between machine cycles and clock cycles, with machine cycles varying from 2 to 12 clock cycles in length. However, the CIP-51 implementation is based solely on clock cycle timing. All instruction timings are specified in terms of clock cycles. Due to the pipelined architecture of the CIP-51, most instructions execute in the same number of clock cycles as there are program bytes in the instruction. Conditional branch instructions take one less clock cycle to complete when the branch is not taken as opposed to when the branch is taken. Table 13.1 is the CIP-51 Instruction Set Summary, which includes the mnemonic, number of bytes, and number of clock cycles for each instruction. 13.1.2. MOVX Instruction and Program Memory In the CIP-51, the MOVX instruction serves three purposes: accessing on-chip XRAM, accessing off-chip XRAM, and writing to on-chip program Flash memory. The Flash access feature provides a mechanism for user software to update program code and use the program memory space for non-volatile data storage (see Section “16. Flash Memory” on page 177). The External Memory Interface provides a fast access to off-chip XRAM (or memory-mapped peripherals) via the MOVX instruction. Refer to Section “17. External Data Memory Interface and On-Chip XRAM” on page 187 for details. Rev. 1.3 125 C8051F060/1/2/3/4/5/6/7 Table 13.1. CIP-51 Instruction Set Summary Mnemonic ADD A, Rn ADD A, direct ADD A, @Ri ADD A, #data ADDC A, Rn ADDC A, direct ADDC A, @Ri ADDC A, #data SUBB A, Rn SUBB A, direct SUBB A, @Ri SUBB A, #data INC A INC Rn INC direct INC @Ri DEC A DEC Rn DEC direct DEC @Ri INC DPTR MUL AB DIV AB DA A ANL A, Rn ANL A, direct ANL A, @Ri ANL A, #data ANL direct, A ANL direct, #data ORL A, Rn ORL A, direct ORL A, @Ri ORL A, #data ORL direct, A ORL direct, #data XRL A, Rn XRL A, direct XRL A, @Ri XRL A, #data XRL direct, A 126 Description Arithmetic Operations Add register to A Add direct byte to A Add indirect RAM to A Add immediate to A Add register to A with carry Add direct byte to A with carry Add indirect RAM to A with carry Add immediate to A with carry Subtract register from A with borrow Subtract direct byte from A with borrow Subtract indirect RAM from A with borrow Subtract immediate from A with borrow Increment A Increment register Increment direct byte Increment indirect RAM Decrement A Decrement register Decrement direct byte Decrement indirect RAM Increment Data Pointer Multiply A and B Divide A by B Decimal adjust A Logical Operations AND Register to A AND direct byte to A AND indirect RAM to A AND immediate to A AND A to direct byte AND immediate to direct byte OR Register to A OR direct byte to A OR indirect RAM to A OR immediate to A OR A to direct byte OR immediate to direct byte Exclusive-OR Register to A Exclusive-OR direct byte to A Exclusive-OR indirect RAM to A Exclusive-OR immediate to A Exclusive-OR A to direct byte Rev. 1.3 Bytes Clock Cycles 1 2 1 2 1 2 1 2 1 2 1 2 1 1 2 1 1 1 2 1 1 1 1 1 1 2 2 2 1 2 2 2 1 2 2 2 1 1 2 2 1 1 2 2 1 4 8 1 1 2 1 2 2 3 1 2 1 2 2 3 1 2 1 2 2 1 2 2 2 2 3 1 2 2 2 2 3 1 2 2 2 2 C8051F060/1/2/3/4/5/6/7 Table 13.1. CIP-51 Instruction Set Summary (Continued) Mnemonic Description XRL direct, #data CLR A CPL A RL A RLC A RR A RRC A SWAP A Exclusive-OR immediate to direct byte Clear A Complement A Rotate A left Rotate A left through Carry Rotate A right Rotate A right through Carry Swap nibbles of A Data Transfer Move Register to A Move direct byte to A Move indirect RAM to A Move immediate to A Move A to Register Move direct byte to Register Move immediate to Register Move A to direct byte Move Register to direct byte Move direct byte to direct byte Move indirect RAM to direct byte Move immediate to direct byte Move A to indirect RAM Move direct byte to indirect RAM Move immediate to indirect RAM Load DPTR with 16-bit constant Move code byte relative DPTR to A Move code byte relative PC to A Move external data (8-bit address) to A Move A to external data (8-bit address) Move external data (16-bit address) to A Move A to external data (16-bit address) Push direct byte onto stack Pop direct byte from stack Exchange Register with A Exchange direct byte with A Exchange indirect RAM with A Exchange low nibble of indirect RAM with A Boolean Manipulation Clear Carry Clear direct bit Set Carry Set direct bit Complement Carry Complement direct bit AND direct bit to Carry MOV A, Rn MOV A, direct MOV A, @Ri MOV A, #data MOV Rn, A MOV Rn, direct MOV Rn, #data MOV direct, A MOV direct, Rn MOV direct, direct MOV direct, @Ri MOV direct, #data MOV @Ri, A MOV @Ri, direct MOV @Ri, #data MOV DPTR, #data16 MOVC A, @A+DPTR MOVC A, @A+PC MOVX A, @Ri MOVX @Ri, A MOVX A, @DPTR MOVX @DPTR, A PUSH direct POP direct XCH A, Rn XCH A, direct XCH A, @Ri XCHD A, @Ri CLR C CLR bit SETB C SETB bit CPL C CPL bit ANL C, bit 3 1 1 1 1 1 1 1 Clock Cycles 3 1 1 1 1 1 1 1 1 2 1 2 1 2 2 2 2 3 2 3 1 2 2 3 1 1 1 1 1 1 2 2 1 2 1 1 1 2 2 2 1 2 2 2 2 3 2 3 2 2 2 3 3 3 3 3 3 3 2 2 1 2 2 2 1 2 1 2 1 2 2 1 2 1 2 1 2 2 Bytes Rev. 1.3 127 C8051F060/1/2/3/4/5/6/7 Table 13.1. CIP-51 Instruction Set Summary (Continued) Mnemonic Description ANL C, /bit ORL C, bit ORL C, /bit MOV C, bit MOV bit, C JC rel JNC rel JB bit, rel JNB bit, rel JBC bit, rel AND complement of direct bit to Carry OR direct bit to carry OR complement of direct bit to Carry Move direct bit to Carry Move Carry to direct bit Jump if Carry is set Jump if Carry is not set Jump if direct bit is set Jump if direct bit is not set Jump if direct bit is set and clear bit Program Branching Absolute subroutine call Long subroutine call Return from subroutine Return from interrupt Absolute jump Long jump Short jump (relative address) Jump indirect relative to DPTR Jump if A equals zero Jump if A does not equal zero Compare direct byte to A and jump if not equal Compare immediate to A and jump if not equal Compare immediate to Register and jump if not equal Compare immediate to indirect and jump if not equal Decrement Register and jump if not zero Decrement direct byte and jump if not zero No operation ACALL addr11 LCALL addr16 RET RETI AJMP addr11 LJMP addr16 SJMP rel JMP @A+DPTR JZ rel JNZ rel CJNE A, direct, rel CJNE A, #data, rel CJNE Rn, #data, rel CJNE @Ri, #data, rel DJNZ Rn, rel DJNZ direct, rel NOP 128 2 2 2 2 2 2 2 3 3 3 Clock Cycles 2 2 2 2 2 2/3 2/3 3/4 3/4 3/4 2 3 1 1 2 3 2 1 2 2 3 3 3 4 5 5 3 4 3 3 2/3 2/3 3/4 3/4 3 3/4 3 4/5 2 3 1 2/3 3/4 1 Bytes Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Notes on Registers, Operands and Addressing Modes: Rn - Register R0-R7 of the currently selected register bank. @Ri - Data RAM location addressed indirectly through R0 or R1. rel - 8-bit, signed (two’s complement) offset relative to the first byte of the following instruction. Used by SJMP and all conditional jumps. direct - 8-bit internal data location’s address. This could be a direct-access Data RAM location (0x000x7F) or an SFR (0x80-0xFF). #data - 8-bit constant #data16 - 16-bit constant bit - Direct-accessed bit in Data RAM or SFR addr11 - 11-bit destination address used by ACALL and AJMP. The destination must be within the same 2K-byte page of program memory as the first byte of the following instruction. addr16 - 16-bit destination address used by LCALL and LJMP. The destination may be anywhere within the 64K-byte program memory space. There is one unused opcode (0xA5) that performs the same function as NOP. All mnemonics copyrighted © Intel Corporation 1980. Rev. 1.3 129 C8051F060/1/2/3/4/5/6/7 13.2. Memory Organization The memory organization of the CIP-51 System Controller is similar to that of a standard 8051. There are two separate memory spaces: program memory and data memory. Program and data memory share the same address space but are accessed via different instruction types. There are 256 bytes of internal data memory and 64 k bytes (C8051F060/1/2/3/4/5) or 32 k bytes (C8051F066/7) of internal program memory address space implemented within the CIP-51. The CIP-51 memory organization is shown in Figure 13.2. Figure 13.2. Memory Map 13.2.1. Program Memory The CIP-51 has a 64 k byte program memory space. The C8051F060/1/2/3/4/5 devices implement 64 k bytes of this program memory space as in-system re-programmable Flash memory, organized in a contiguous block from addresses 0x0000 to 0xFFFF. Note: 1024 bytes (0xFC00 to 0xFFFF) of this memory are reserved, and are not available for user program storage. The C8051F066/7 implement 32 k bytes of this program memory space as in-system re-programmable Flash memory, organized in a contiguous block from addresses 0x0000 to 0x7FFF. Program memory is normally assumed to be read-only (using the MOVC instruction). However, the CIP-51 can write to program memory by enabling Flash writes, and using the MOVX instruction. This feature provides a mechanism for the CIP-51 to update program code and use the program memory space for nonvolatile data storage. Refer to Section “16. Flash Memory” on page 177 for further details. 130 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 13.2.2. Data Memory The CIP-51 implements 256 bytes of internal RAM mapped into the data memory space from 0x00 through 0xFF. The lower 128 bytes of data memory are used for general purpose registers and scratch pad memory. Either direct or indirect addressing may be used to access the lower 128 bytes of data memory. Locations 0x00 through 0x1F are addressable as four banks of general purpose registers, each bank consisting of eight byte-wide registers. The next 16 bytes, locations 0x20 through 0x2F, may either be addressed as bytes or as 128 bit locations accessible with the direct addressing mode. The upper 128 bytes of data memory are accessible only by indirect addressing. This region occupies the same address space as the Special Function Registers (SFRs) but is physically separate from the SFR space. The addressing mode used by an instruction when accessing locations above 0x7F determines whether the CPU accesses the upper 128 bytes of data memory space or the SFRs. Instructions that use direct addressing above 0x7F will access the SFR space. Instructions using indirect addressing above 0x7F access the upper 128 bytes of data memory. Figure 13.2 illustrates the data memory organization of the CIP-51. 13.2.3. General Purpose Registers The lower 32 bytes of data memory, locations 0x00 through 0x1F, may be addressed as four banks of general-purpose registers. Each bank consists of eight byte-wide registers designated R0 through R7. Only one of these banks may be enabled at a time. Two bits in the program status word, RS0 (PSW.3) and RS1 (PSW.4), select the active register bank (see description of the PSW in Figure 13.16). This allows fast context switching when entering subroutines and interrupt service routines. Indirect addressing modes use registers R0 and R1 as index registers. 13.2.4. Bit Addressable Locations In addition to direct access to data memory organized as bytes, the sixteen data memory locations at 0x20 through 0x2F are also accessible as 128 individually addressable bits. Each bit has a bit address from 0x00 to 0x7F. Bit 0 of the byte at 0x20 has bit address 0x00 while bit 7 of the byte at 0x20 has bit address 0x07. Bit 7 of the byte at 0x2F has bit address 0x7F. A bit access is distinguished from a full byte access by the type of instruction used (a bit source or destination operand as opposed to a byte source or destination). The MCS-51™ assembly language allows an alternate notation for bit addressing of the form XX.B where XX is the byte address and B is the bit position within the byte. For example, the instruction: MOV C, 22.3h moves the Boolean value at 0x13 (bit 3 of the byte at location 0x22) into the Carry flag. 13.2.5. Stack A programmer's stack can be located anywhere in the 256 byte data memory. The stack area is designated using the Stack Pointer (SP, address 0x81) SFR. The SP will point to the last location used. The next value pushed on the stack is placed at SP+1 and then SP is incremented. A reset initializes the stack pointer to location 0x07; therefore, the first value pushed on the stack is placed at location 0x08, which is also the first register (R0) of register bank 1. Thus, if more than one register bank is to be used, the SP should be initialized to a location in the data memory not being used for data storage. The stack depth can extend up to 256 bytes. The MCUs also have built-in hardware for a stack record which is accessed by the debug logic. The stack record is a 32-bit shift register, where each PUSH or increment SP pushes one record bit onto the register, Rev. 1.3 131 C8051F060/1/2/3/4/5/6/7 and each CALL pushes two record bits onto the register. (A POP or decrement SP pops one record bit, and a RET pops two record bits, also.) The stack record circuitry can also detect an overflow or underflow on the 32-bit shift register, and can notify the debug software even with the MCU running at speed. 13.2.6. Special Function Registers The direct-access data memory locations from 0x80 to 0xFF constitute the Special Function Registers (SFRs). The SFRs provide control and data exchange with the CIP-51's resources and peripherals. The CIP-51 duplicates the SFRs found in a typical 8051 implementation as well as implementing additional SFRs used to configure and access the sub-systems unique to the MCU. This allows the addition of new functionality while retaining compatibility with the MCS-51™ instruction set. Table 13.2 lists the SFRs implemented in the CIP-51 System Controller. The SFRs are accessed whenever the direct addressing mode is used to access memory locations from 0x80 to 0xFF. SFRs with addresses ending in 0x0 or 0x8 (e.g. P0, TCON, P1, SCON, IE, etc.) are bitaddressable as well as byte-addressable. All other SFRs are byte-addressable only. Unoccupied addresses in the SFR space are reserved for future use. Accessing these areas will have an indeterminate effect and should be avoided. Refer to the corresponding pages of the datasheet, as indicated in Table 13.3, for a detailed description of each register. 13.2.6.1.SFR Paging The CIP-51 features SFR paging, allowing the device to map many SFRs into the 0x80 to 0xFF memory address space. The SFR memory space has 256 pages. In this way, each memory location from 0x80 to 0xFF can access up to 256 SFRs. The C8051F06x family of devices utilizes five SFR pages: 0, 1, 2, 3, and F. SFR pages are selected using the Special Function Register Page Selection register, SFRPAGE (see Figure 13.10). The procedure for reading and writing an SFR is as follows: 1. Select the appropriate SFR page number using the SFRPAGE register. 2. Use direct accessing mode to read or write the special function register (MOV instruction). 13.2.6.2.Interrupts and SFR Paging When an interrupt occurs, the SFR Page Register will automatically switch to the SFR page containing the flag bit that caused the interrupt. The automatic SFR Page switch function conveniently removes the burden of switching SFR pages from the interrupt service routine. Upon execution of the RETI instruction, the SFR page is automatically restored to the SFR Page in use prior to the interrupt. This is accomplished via a three-byte SFR Page Stack. The top byte of the stack is SFRPAGE, the current SFR Page. The second byte of the SFR Page Stack is SFRNEXT. The third, or bottom byte of the SFR Page Stack is SFRLAST. On interrupt, the current SFRPAGE value is pushed to the SFRNEXT byte, and the value of SFRNEXT is pushed to SFRLAST. Hardware then loads SFRPAGE with the SFR Page containing the flag bit associated with the interrupt. On a return from interrupt, the SFR Page Stack is popped resulting in the value of SFRNEXT returning to the SFRPAGE register, thereby restoring the SFR page context without software intervention. The value in SFRLAST (0x00 if there is no SFR Page value in the bottom of the stack) of the stack is placed in SFRNEXT register. If desired, the values stored in SFRNEXT and SFRLAST may be modified during an interrupt, enabling the CPU to return to a different SFR Page upon execution of the RETI instruction (on interrupt exit). Modifying registers in the SFR Page Stack does not cause a push or pop of the stack. Only interrupt calls and returns will cause push/pop operations on the SFR Page Stack. 132 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 13.3. SFR Page Stack Automatic hardware switching of the SFR Page on interrupts may be enabled or disabled as desired using the SFR Automatic Page Control Enable Bit located in the SFR Page Control Register (SFRPGCN). This function defaults to ‘enabled’ upon reset. In this way, the autoswitching function will be enabled unless disabled in software. A summary of the SFR locations (address and SFR page) is provided in Table 13.2. in the form of an SFR memory map. Each memory location in the map has an SFR page row, denoting the page in which that SFR resides. Note that certain SFRs are accessible from ALL SFR pages, and are denoted by the “(ALL PAGES)” designation. For example, the Port I/O registers P0, P1, P2, and P3 all have the “(ALL PAGES)” designation, indicating these SFRs are accessible from all SFR pages regardless of the SFRPAGE register value. Rev. 1.3 133 C8051F060/1/2/3/4/5/6/7 13.2.6.3.SFR Page Stack Example The following is an example that shows the operation of the SFR Page Stack during interrupts. In this example, the SFR Page Control is left in the default enabled state (i.e., SFRPGEN = 1), and the CIP-51 is executing in-line code that is writing values to Port 5 (SFR “P5”, located at address 0xD8 on SFR Page 0x0F). The device is also using the Programmable Counter Array (PCA) and the 10-bit ADC (ADC2) window comparator to monitor a voltage. The PCA is timing a critical control function in its interrupt service routine (ISR), so its interrupt is enabled and is set to high priority. The ADC2 is monitoring a voltage that is less important, but to minimize the software overhead its window comparator is being used with an associated ISR that is set to low priority. At this point, the SFR page is set to access the Port 5 SFR (SFRPAGE = 0x0F). See Figure 13.4 below. Figure 13.4. SFR Page Stack While Using SFR Page 0x0F To Access Port 5 134 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 While CIP-51 executes in-line code (writing values to Port 5 in this example), ADC2 Window Comparator Interrupt occurs. The CIP-51 vectors to the ADC2 Window Comparator ISR and pushes the current SFR Page value (SFR Page 0x0F) into SFRNEXT in the SFR Page Stack. The SFR page needed to access ADC2’s SFRs is then automatically placed in the SFRPAGE register (SFR Page 0x02). SFRPAGE is considered the “top” of the SFR Page Stack. Software can now access the ADC2 SFRs. Software may switch to any SFR Page by writing a new value to the SFRPAGE register at any time during the ADC2 ISR to access SFRs that are not on SFR Page 0x02. See Figure 13.5 below. Figure 13.5. SFR Page Stack After ADC2 Window Comparator Interrupt Occurs Rev. 1.3 135 C8051F060/1/2/3/4/5/6/7 While in the ADC2 ISR, a PCA interrupt occurs. Recall the PCA interrupt is configured as a high priority interrupt, while the ADC2 interrupt is configured as a low priority interrupt. Thus, the CIP-51 will now vector to the high priority PCA ISR. Upon doing so, the CIP-51 will automatically place the SFR page needed to access the PCA’s special function registers into the SFRPAGE register, SFR Page 0x00. The value that was in the SFRPAGE register before the PCA interrupt (SFR Page 2 for ADC2) is pushed down the stack into SFRNEXT. Likewise, the value that was in the SFRNEXT register before the PCA interrupt (in this case SFR Page 0x0F for Port 5) is pushed down to the SFRLAST register, the “bottom” of the stack. Note that a value stored in SFRLAST (via a previous software write to the SFRLAST register) will be overwritten. See Figure 13.6 below. Figure 13.6. SFR Page Stack Upon PCA Interrupt Occurring During an ADC2 ISR 136 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 On exit from the PCA interrupt service routine, the CIP-51 will return to the ADC2 Window Comparator ISR. On execution of the RETI instruction, SFR Page 0x00 used to access the PCA registers will be automatically popped off of the SFR Page Stack, and the contents of the SFRNEXT register will be moved to the SFRPAGE register. Software in the ADC2 ISR can continue to access SFRs as it did prior to the PCA interrupt. Likewise, the contents of SFRLAST are moved to the SFRNEXT register. Recall this was the SFR Page value 0x0F being used to access Port 5 before the ADC2 interrupt occurred. See Figure 13.7 below. Figure 13.7. SFR Page Stack Upon Return From PCA Interrupt Rev. 1.3 137 C8051F060/1/2/3/4/5/6/7 On the execution of the RETI instruction in the ADC2 Window Comparator ISR, the value in SFRPAGE register is overwritten with the contents of SFRNEXT. The CIP-51 may now access the Port 5 SFR bits as it did prior to the interrupts occurring. See Figure 13.8 below. Figure 13.8. SFR Page Stack Upon Return From ADC2 Window Interrupt Note that in the above example, all three bytes in the SFR Page Stack are accessible via the SFRPAGE, SFRNEXT, and SFRLAST special function registers. If the stack is altered while servicing an interrupt, it is possible to return to a different SFR Page upon interrupt exit than selected prior to the interrupt call. Direct access to the SFR Page stack can be useful to enable real-time operating systems to control and manage context switching between multiple tasks. Push operations on the SFR Page Stack only occur on interrupt service, and pop operations only occur on interrupt exit (execution on the RETI instruction). The automatic switching of the SFRPAGE and operation of the SFR Page Stack as described above can be disabled in software by clearing the SFR Automatic Page Enable Bit (SFRPGEN) in the SFR Page Control Register (SFRPGCN). See Figure 13.9. 138 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 13.9. SFRPGCN: SFR Page Control Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value SFRPGEN 00000001 - - - - - - - Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-1: Bit0: Bit0 SFR Address: 0x96 SFR Page: F Reserved. SFRPGEN: SFR Automatic Page Control Enable. Upon interrupt, the C8051 Core will vector to the specified interrupt service routine and automatically switch the SFR page to the corresponding peripheral or function’s SFR page. This bit is used to control this autopaging function. 0: SFR Automatic Paging disabled. C8051 core will not automatically change to the appropriate SFR page (i.e., the SFR page that contains the SFRs for the peripheral/function that was the source of the interrupt). 1: SFR Automatic Paging enabled. Upon interrupt, the C8051 will switch the SFR page to the page that contains the SFRs for the peripheral or function that is the source of the interrupt. Figure 13.10. SFRPAGE: SFR Page Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0x84 SFR Page: All Pages SFR Page Bits: Byte Represents the SFR Page the C8051 MCU uses when reading or modifying SFRs. Write: Sets the SFR Page. Read: Byte is the SFR page the C8051 MCU is using. When enabled in the SFR Page Control Register (SFRPGCN), the C8051 will automatically switch to the SFR Page that contains the SFRs of the corresponding peripheral/function that caused the interrupt, and return to the previous SFR page upon return from interrupt (unless SFR Stack was altered before a returning from the interrupt). SFRPAGE is the top byte of the SFR Page Stack, and push/pop events of this stack are caused by interrupts (and not by reading/writing to the SFRPAGE register) Rev. 1.3 139 C8051F060/1/2/3/4/5/6/7 Figure 13.11. SFRNEXT: SFR Next Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0x85 SFR Page: All Pages SFR Page Stack Bits: SFR page context is retained upon interrupts/return from interrupts in a 3 byte SFR Page Stack: SFRPAGE is the first entry, SFRNEXT is the second, and SFRLAST is the third entry. The SFR stack bytes may be used to alter the context in the SFR Page Stack, and will not cause the stack to ‘push’ or ‘pop’. Only interrupts and return from interrupt cause push and pop the SFR Page Stack. Write: Sets the SFR Page contained in the second byte of the SFR Stack. This will cause the SFRPAGE SFR to have this SFR page value upon a return from interrupt. Read: Returns the value of the SFR page contained in the second byte of the SFR stack. This is the value that will go to the SFR Page register upon a return from interrupt. Figure 13.12. SFRLAST: SFR Last Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: 140 Bit0 SFR Address: 0x86 SFR Page: All Pages SFR Page Stack Bits: SFR page context is retained upon interrupts/return from interrupts in a 3 byte SFR Page Stack: SFRPAGE is the first entry, SFRNEXT is the second, and SFRLAST is the third entry. The SFR stack bytes may be used to alter the context in the SFR Page Stack, and will not cause the stack to ‘push’ or ‘pop’. Only interrupts and return from interrupt cause push and pop the SFR Page Stack. Write: Sets the SFR Page in the last entry of the SFR Stack. This will cause the SFRNEXT SFR to have this SFR page value upon a return from interrupt. Read: Returns the value of the SFR page contained in the last entry of the SFR stack. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Table 13.2. Special Function Register (SFR) Memory Map A D D R E S S SFR P A G E 0 F8 1 2 3 F 0(8) 1(9) 2(A) SPI0CN CAN0CN PCA0L PCA0H DMA0CF P7 DMA0CTL 3(B) 4(C) 5(D) 6(E) 7(F) PCA0CPL0 PCA0CPH0 PCA0CPL1 PCA0CPH1 WDTCN (ALL PAGES) DMA0CTH DMA0CSL DMA0CSH DMA0BND DMA0ISW 0 F0 E8 E0 D8 D0 C8 C0 1 B 2 (ALL PAGES) 3 F 0 ADC0CN PCA0CPL2 1 ADC1CN 2 ADC2CN 3 F P6 0 PCA0CPL5 1 ACC 2 (ALL PAGES) 3 F XBR0 0 PCA0MD PCA0CN 1 CAN0DATL CAN0DATH 2 3 DMA0DAL DMA0CN F P5 0 REF0CN 1 REF1CN PSW 2 REF2CN (ALL PAGES) 3 F 0 TMR2CF TMR2CN 1 TMR3CF TMR3CN 2 TMR4CF TMR4CN 3 F P4 0 SMB0CN SMB0STA 1 CAN0STA 2 3 F PCA0CPH2 PCA0CPL3 PCA0CPH3 PCA0CPL4 PCA0CPH4 1 IP 2 (ALL PAGES) 3 F 0(8) 1(9) RSTSRC PCA0CPH5 EIE1 EIE2 (ALL PAGES) (ALL PAGES) XBR1 XBR2 XBR3 PCA0CPM0 PCA0CPM1 PCA0CPM2 PCA0CPM3 PCA0CPM4 PCA0CPM5 CAN0ADR CAN0TST DMA0DAH DMA0DSL DMA0DSH DAC0L DAC1L DAC0H DAC1H DAC0CN DAC1CN RCAP2L RCAP3L RCAP4L RCAP2H RCAP3H RCAP4H TMR2L TMR3L TMR4L TMR2H TMR3H TMR4H SMB0DAT SMB0ADR ADC0GTL ADC0GTH ADC0LTL ADC0LTH ADC2GTL ADC2GTH ADC2LTL ADC2LTH ADC0L ADC1L ADC2L ADC0H ADC1H ADC2H 6(E) 7(F) AMX2CF AMX2SL ADC0CF ADC1CF ADC2CF ADC0CPT 2(A) ADC0CCF 3(B) 4(C) AMX0SL SADEN0 0 B8 EIP1 EIP2 (ALL PAGES) (ALL PAGES) Rev. 1.3 DMA0IPT 5(D) DMA0IDT SMB0CR 141 C8051F060/1/2/3/4/5/6/7 Table 13.2. Special Function Register (SFR) Memory Map B0 0 FLSCL 1 P3 2 (ALL PAGES) 3 F FLACL SADDR0 0 A8 1 IE 2 (ALL PAGES) 3 F 0 A0 1 2 3 F SCON0 SCON1 88 EMI0CF SBUF0 SBUF1 SPI0CFG SPI0DAT P1MDIN P2MDIN P0MDOUT P1MDOUT SPI0CKR P2MDOUT P3MDOUT P4MDOUT P5MDOUT P6MDOUT P7MDOUT TH1 SFRPGCN CKCON CLKSEL PSCTL SSTA0 0 90 EMI0CN 1 P2 2 (ALL PAGES) 3 F 0 98 EMI0TC 1 P1 2 (ALL PAGES) 3 F 0 1 2 3 F TCON CPT0CN CPT1CN CPT2CN TMOD CPT0MD CPT1MD CPT2MD TL0 TL1 TH0 OSCICN OSCICL OSCXCN 0 80 142 1 P0 SP DPL DPH SFRPAGE SFRNEXT SFRLAST PCON 2 (ALL PAGES) (ALL PAGES) (ALL PAGES) (ALL PAGES) (ALL PAGES) (ALL PAGES) (ALL PAGES) (ALL PAGES) 3 F 0(8) 1(9) 2(A) 3(B) 4(C) 5(D) 6(E) 7(F) Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Table 13.3. Special Function Registers SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address SFR Page Description B 0xF0 All Pages B Register ACC 0xE0 All Pages Accumulator ADC0CCF 0xBB F ADC0 Calibration Coefficient ADC0CF 0xBC 0 ADC0 Configuration ADC0CN 0xE8 0 ADC0 Control ADC0CPT 0xBA F ADC0 Calibration Pointer ADC0GTH 0xC5 0 ADC0 Greater-Than High ADC0GTL 0xC4 0 ADC0 Greater-Than Low ADC0H 0xBF 0 ADC0 Data Word High ADC0L 0xBE 0 ADC0 Data Word Low ADC0LTH 0xC7 0 ADC0 Less-Than High ADC0LTL 0xC6 0 ADC0 Less-Than Low ADC1CF 0xBC 1 ADC1 Configuration ADC1CN 0xE8 1 ADC1 Control ADC1H 0xBF 1 ADC1 Data Word High ADC1L 0xBE 1 ADC1 Data Word Low ADC2CF 0xBC 2 ADC2 Configuration page 94*5 ADC2CN 0xE8 2 ADC2 Control page 96*5 ADC2GTH 0xC5 2 ADC2 Greater-Than High page 97*5 ADC2GTL 0xC4 2 ADC2 Greater-Than Low page 97*5 ADC2H 0xBF 2 ADC2 Data Word High page 95*5 ADC2L 0xBE 2 ADC2 Data Word Low page 95*5 ADC2LTH 0xC7 2 ADC2 Less-Than High page 98*5 ADC2LTL AMX0SL AMX2CF 0xC6 0xBB 0xBA 2 0 2 ADC2 Less-Than Low ADC0 Multiplexer Channel Select ADC2 Analog Multiplexer Configuration page 98*5 page 57 AMX2SL 0xBB 2 ADC2 Analog Multiplexer Channel Select page 93*5 CAN0ADR 0xDA 1 CAN0 Address page 232*5 CAN0CN 0xF8 1 CAN0 Control page 232*5 CAN0DATH 0xD9 1 CAN0 Data High page 231*5 CAN0DATL 0xD8 1 CAN0 Data Low page 231*5 CAN0STA 0xC0 1 CAN0 Status page 233*5 CAN0TST CKCON CLKSEL CPT0CN CPT0MD CPT1CN CPT1MD CPT2CN 0xDB 0x8E 0x97 0x88 0x89 0x88 0x89 0x88 1 0 F 1 1 2 2 3 CAN0 Test Clock Control Oscillator Clock Selection Register Comparator 0 Control Comparator 0 Configuration Comparator 1 Control Comparator 1 Configuration Comparator 2 Control page 233*5 page 293 page 173 page 120 page 121 page 120 page 121 page 120 Rev. 1.3 Page No. page 150 page 150 page 68 page 58 page 60 page 68 page 69 page 69 page 63 page 63 page 70 page 70 page 59 page 61 page 65 page 65 page 94*5 143 C8051F060/1/2/3/4/5/6/7 Table 13.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address SFR Page Description CPT2MD 0x89 3 Comparator 2 Configuration DAC0CN 0xD4 0 DAC0 Control page 106*5 DAC0H 0xD3 0 DAC0 High page 105*5 DAC0L 0xD2 0 DAC0 Low page 105*5 DAC1CN 0xD4 1 DAC1 Control page 108*5 DAC1H 0xD3 1 DAC1 High page 107*5 DAC1L DMA0BND DMA0CF DMA0CN DMA0CSH DMA0CSL DMA0CTH DMA0CTL DMA0DAH DMA0DAL DMA0DSH DMA0DSL DMA0IDT DMA0IPT DMA0ISW DPH DPL EIE1 EIE2 EIP1 EIP2 EMI0CF 0xD2 0xFD 0xF8 0xD8 0xFC 0xFB 0xFA 0xF9 0xDA 0xD9 0xDC 0xDB 0xDE 0xDD 0xFE 0x83 0x82 0xE6 0xE7 0xF6 0xF7 0xA3 1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 All Pages All Pages All Pages All Pages All Pages All Pages 0 DAC1 Low DMA0 Instruction Boundary DMA0 Configuration DMA0 Control DMA0 Repeat Counter Status High Byte DMA0 Repeat Counter Status Low Byte DMA0 Repeat Counter Limit High Byte DMA0 Repeat Counter Limit Low Byte DMA0 Data Address Beginning High Byte DMA0 Data Address Beginning Low Byte DMA0 Data Address Pointer High Byte DMA0 Data Address Pointer Low Byte DMA0 Instruction Write Data DMA0 Instruction Write Address DMA0 Instruction Status Data Pointer High Data Pointer Low Extended Interrupt Enable 1 Extended Interrupt Enable 2 Extended Interrupt Priority 1 Extended Interrupt Priority 2 EMIF Configuration page 107*5 page 83 page 81 page 80 page 85 page 85 page 85 page 85 page 84 page 84 page 84 page 84 page 82 page 82 page 83 page 148 page 148 page 156 page 157 page 158 page 159 EMI0CN 0xA2 0 EMIF Control page 189*1 EMI0TC FLACL FLSCL IE IP OSCICL OSCICN OSCXCN P0 P0MDOUT P1 P1MDIN P1MDOUT P2 0xA1 0xB7 0xB7 0xA8 0xB8 0x8B 0x8A 0x8C 0x80 0xA4 0x90 0xAD 0xA5 0xA0 0 F 0 All Pages All Pages F F F All Pages F All Pages F F All Pages EMIF Timing Control Flash Access Limit Flash Scale Interrupt Enable Interrupt Priority Internal Oscillator Calibration Internal Oscillator Control External Oscillator Control Port 0 Latch Port 0 Output Mode Configuration Port 1 Latch Port 1 Input Mode Port 1 Output Mode Configuration Port 2 Latch page 194*1 page 182 page 184 page 154 page 155 page 172 page 172 page 174 page 214 page 214 page 215 page 215 page 216 page 216 144 Rev. 1.3 Page No. page 121 page 189*1 C8051F060/1/2/3/4/5/6/7 Table 13.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address SFR Page Description P2MDIN 0xAE F Port 2 Input Mode P2MDOUT 0xA6 F Port 2 Output Mode Configuration P3 0xB0 All Pages Port 3 Latch page 218*1 P3MDOUT 0xA7 F Port 3 Output Mode Configuration page 218*1 P4 0xC8 F Port 4 Latch page 221*1 P4MDOUT 0x9C F Port 4 Output Mode Configuration page 221*1 P5 0xD8 F Port 5 Latch page 222*1 P5MDOUT 0x9D F Port 5 Output Mode Configuration page 222*1 P6 0xE8 F Port 6 Latch page 223*1 P6MDOUT 0x9E F Port 6 Output Mode Configuration page 223*1 P7 0xF8 F Port 7 Latch page 224*1 P7MDOUT PCA0CN PCA0CPH0 PCA0CPH1 PCA0CPH2 PCA0CPH3 PCA0CPH4 PCA0CPH5 PCA0CPL0 PCA0CPL1 PCA0CPL2 PCA0CPL3 PCA0CPL4 PCA0CPL5 PCA0CPM0 PCA0CPM1 PCA0CPM2 PCA0CPM3 PCA0CPM4 PCA0CPM5 PCA0H PCA0L PCA0MD PCON PSCTL PSW RCAP2H RCAP2L RCAP3H RCAP3L RCAP4H RCAP4L 0x9F 0xD8 0xFC 0xFE 0xEA 0xEC 0xEE 0xE2 0xFB 0xFD 0xE9 0xEB 0xED 0xE1 0xDA 0xDB 0xDC 0xDD 0xDE 0xDF 0xFA 0xF9 0xD9 0x87 0x8F 0xD0 0xCB 0xCA 0xCB 0xCA 0xCB 0xCA F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 All Pages 0 All Pages 0 0 1 1 2 2 Port 7 Output Mode Configuration PCA Control PCA Capture 0 High PCA Capture 1 High PCA Capture 2 High PCA Capture 3 High PCA Capture 4 High PCA Capture 5 High PCA Capture 0 Low PCA Capture 1 Low PCA Capture 2 Low PCA Capture 3 Low PCA Capture 4 Low PCA Capture 5 Low PCA Module 0 Mode Register PCA Module 1 Mode Register PCA Module 2 Mode Register PCA Module 3 Mode Register PCA Module 4 Mode Register PCA Module 5 Mode Register PCA Counter High PCA Counter Low PCA Mode Power Control Program Store R/W Control Program Status Word Timer/Counter 2 Capture/Reload High Timer/Counter 2 Capture/Reload Low Timer/Counter 3 Capture/Reload High Timer/Counter 3 Capture/Reload Low Timer/Counter 4 Capture/Reload High Timer/Counter 4 Capture/Reload Low page 224*1 page 312 page 316 page 316 page 316 page 316 page 316 page 316 page 316 page 316 page 316 page 316 page 316 page 316 page 314 page 314 page 314 page 314 page 314 page 314 page 315 page 315 page 313 page 161 page 185 page 149 page 301 page 301 page 301 page 301 page 301 page 301 Rev. 1.3 Page No. page 217 page 217 145 C8051F060/1/2/3/4/5/6/7 Table 13.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address SFR Page Description REF0CN 0xD1 0 Voltage Reference Control 0 REF1CN 0xD1 1 Voltage Reference Control 1 REF2CN 0xD1 2 RSTSRC SADDR0 SADEN0 SBUF0 SBUF1 SCON0 SCON1 SFRLAST SFRNEXT SFRPAGE SFRPGCN SMB0ADR SMB0CN SMB0CR SMB0DAT SMB0STA SP SPI0CFG SPI0CKR SPI0CN SPI0DAT SSTA0 TCON TH0 TH1 TL0 TL1 TMOD TMR2CF TMR2CN TMR2H TMR2L TMR3CF TMR3CN TMR3H TMR3L TMR4CF TMR4CN TMR4H 0xEF 0xA9 0xB9 0x99 0x99 0x98 0x98 0x86 0x85 0x84 0x96 0xC3 0xC0 0xCF 0xC2 0xC1 0x81 0x9A 0x9D 0xF8 0x9B 0x91 0x88 0x8C 0x8D 0x8A 0x8B 0x89 0xC9 0xC8 0xCD 0xCC 0xC9 0xC8 0xCD 0xCC 0xC9 0xC8 0xCD 0 0 0 0 1 0 1 All Pages All Pages All Pages F 0 0 0 0 0 All Pages 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 2 2 2 146 Voltage Reference Control 2 Reset Source UART 0 Slave Address UART 0 Slave Address Enable UART 0 Data Buffer UART 1 Data Buffer UART 0 Control UART 1 Control SFR Page Stack Access Register SFR Page Register SFR Page Register SFR Page Control Register SMBus Slave Address SMBus Control SMBus Clock Rate SMBus Data SMBus Status Stack Pointer SPI Configuration SPI Clock Rate Control SPI Control SPI Data UART 0 Status Timer/Counter Control Timer/Counter 0 High Timer/Counter 1 High Timer/Counter 0 Low Timer/Counter 1 Low Timer/Counter Mode Timer/Counter 2 Configuration Timer/Counter 2 Control Timer/Counter 2 High Timer/Counter 2 Low Timer/Counter 3 Configuration Timer/Counter 3 Control Timer/Counter 3 High Timer/Counter 3 Low Timer/Counter 4 Configuration Timer/Counter 4 Control Timer/Counter 4 High Rev. 1.3 Page No. page 62 page 62 page 112*2, page 114*3, page 116*5 page 168 page 276 page 276 page 276 page 283 page 274 page 282 page 140 page 140 page 139 page 139 page 246 page 243 page 244 page 245 page 247 page 148 page 258 page 260 page 259 page 261 page 275 page 291 page 294 page 294 page 294 page 294 page 292 page 300 page 299 page 302 page 301 page 300 page 299 page 302 page 301 page 300 page 299 page 302 C8051F060/1/2/3/4/5/6/7 Table 13.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address SFR Page Description TMR4L 0xCC 2 Timer/Counter 4 Low WDTCN 0xFF All Pages Watchdog Timer Control XBR0 0xE1 F Port I/O Crossbar Control 0 XBR1 0xE2 F Port I/O Crossbar Control 1 XBR2 0xE3 F Port I/O Crossbar Control 2 XBR3 0xE4 F Port I/O Crossbar Control 3 Page No. page 301 page 167 page 210 page 211 page 212 page 213 *1 Refers to a register in the C8051F060/2/4/6 only. Refers to a register in the C8051F060/2 only. *3 Refers to a register in the C8051F061/3 only. *4 Refers to a register in the C8051F060/1/2/3 only. *5 Refers to a register in the C8051F064/5/6/7 only. *2 Rev. 1.3 147 C8051F060/1/2/3/4/5/6/7 13.2.7. Register Descriptions Following are descriptions of SFRs related to the operation of the CIP-51 System Controller. Reserved bits should not be set to logic l. Future product versions may use these bits to implement new features in which case the reset value of the bit will be logic 0, selecting the feature's default state. Detailed descriptions of the remaining SFRs are included in the sections of the datasheet associated with their corresponding system function. Figure 13.13. SP: Stack Pointer R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000111 Bits7-0: Bit0 SFR Address: 0x81 SFR Page: All Pages SP: Stack Pointer. The Stack Pointer holds the location of the top of the stack. The stack pointer is incremented before every PUSH operation. The SP register defaults to 0x07 after reset. Figure 13.14. DPL: Data Pointer Low Byte R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0x82 SFR Page: All Pages DPL: Data Pointer Low. The DPL register is the low byte of the 16-bit DPTR. DPTR is used to access indirectly addressed XRAM and Flash memory. Figure 13.15. DPH: Data Pointer High Byte R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: 148 Bit0 SFR Address: 0x83 SFR Page: All Pages DPH: Data Pointer High. The DPH register is the high byte of the 16-bit DPTR. DPTR is used to access indirectly addressed XRAM and Flash memory. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 13.16. PSW: Program Status Word R/W R/W R/W R/W R/W R/W R/W R/W Reset Value CY AC F0 RS1 RS0 OV F1 PARITY 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bits4-3: Bit2: Bit1: Bit0: Bit Addressable SFR Address: 0xD0 SFR Page: All Pages Bit0 CY: Carry Flag. This bit is set when the last arithmetic operation resulted in a carry (addition) or a borrow (subtraction). It is cleared to 0 by all other arithmetic operations. AC: Auxiliary Carry Flag. This bit is set when the last arithmetic operation resulted in a carry into (addition) or a borrow from (subtraction) the high order nibble. It is cleared to 0 by all other arithmetic operations. F0: User Flag 0. This is a bit-addressable, general purpose flag for use under software control. RS1-RS0: Register Bank Select. These bits select which register bank is used during register accesses. RS1 RS0 Register Bank Address 0 0 1 1 0 1 0 1 0 1 2 3 0x00 - 0x07 0x08 - 0x0F 0x10 - 0x17 0x18 - 0x1F OV: Overflow Flag. This bit is set to 1 under the following circumstances: • An ADD, ADDC, or SUBB instruction causes a sign-change overflow. • A MUL instruction results in an overflow (result is greater than 255). • A DIV instruction causes a divide-by-zero condition. The OV bit is cleared to 0 by the ADD, ADDC, SUBB, MUL, and DIV instructions in all other cases. F1: User Flag 1. This is a bit-addressable, general purpose flag for use under software control. PARITY: Parity Flag. This bit is set to 1 if the sum of the eight bits in the accumulator is odd and cleared if the sum is even. Rev. 1.3 149 C8051F060/1/2/3/4/5/6/7 Figure 13.17. ACC: Accumulator R/W R/W R/W R/W R/W R/W R/W R/W Reset Value ACC.7 ACC.6 ACC.5 ACC.4 ACC.3 ACC.2 ACC.1 ACC.0 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-0: Bit Addressable SFR Address: 0xE0 SFR Page: All Pages Bit0 ACC: Accumulator. This register is the accumulator for arithmetic operations. Figure 13.18. B: B Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value B.7 B.6 B.5 B.4 B.3 B.2 B.1 B.0 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-0: 150 Bit Addressable SFR Address: 0xF0 SFR Page: All Pages Bit0 B: B Register. This register serves as a second accumulator for certain arithmetic operations. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 13.3. Interrupt Handler The CIP-51 includes an extended interrupt system supporting a total of 22 interrupt sources with two priority levels. The allocation of interrupt sources between on-chip peripherals and external inputs pins varies according to the specific version of the device. Each interrupt source has one or more associated interruptpending flag(s) located in an SFR. When a peripheral or external source meets a valid interrupt condition, the associated interrupt-pending flag is set to logic 1. If interrupts are enabled for the source, an interrupt request is generated when the interrupt-pending flag is set. As soon as execution of the current instruction is complete, the CPU generates an LCALL to a predetermined address to begin execution of an interrupt service routine (ISR). Each ISR must end with an RETI instruction, which returns program execution to the next instruction that would have been executed if the interrupt request had not occurred. If interrupts are not enabled, the interrupt-pending flag is ignored by the hardware and program execution continues as normal. (The interrupt-pending flag is set to logic 1 regardless of the interrupt's enable/disable state.) Each interrupt source can be individually enabled or disabled through the use of an associated interrupt enable bit in an SFR (IE-EIE2). However, interrupts must first be globally enabled by setting the EA bit (IE.7) to logic 1 before the individual interrupt enables are recognized. Setting the EA bit to logic 0 disables all interrupt sources regardless of the individual interrupt-enable settings. Some interrupt-pending flags are automatically cleared by the hardware when the CPU vectors to the ISR. However, most are not cleared by the hardware and must be cleared by software before returning from the ISR. If an interrupt-pending flag remains set after the CPU completes the return-from-interrupt (RETI) instruction, a new interrupt request will be generated immediately and the CPU will re-enter the ISR after the completion of the next instruction. 13.3.1. MCU Interrupt Sources and Vectors The MCUs support 22 interrupt sources. Software can simulate an interrupt event by setting any interruptpending flag to logic 1. If interrupts are enabled for the flag, an interrupt request will be generated and the CPU will vector to the ISR address associated with the interrupt-pending flag. MCU interrupt sources, associated vector addresses, priority order and control bits are summarized in Table 13.4. Refer to the datasheet section associated with a particular on-chip peripheral for information regarding valid interrupt conditions for the peripheral and the behavior of its interrupt-pending flag(s). 13.3.2. External Interrupts The external interrupt sources (/INT0 and /INT1) are configurable as active-low level-sensitive or activelow edge-sensitive inputs depending on the setting of bits IT0 (TCON.0) and IT1 (TCON.2). IE0 (TCON.1) and IE1 (TCON.3) serve as the interrupt-pending flag for the /INT0 and /INT1 external interrupts, respectively. If an /INT0 or /INT1 external interrupt is configured as edge-sensitive, the corresponding interruptpending flag is automatically cleared by the hardware when the CPU vectors to the ISR. When configured as level sensitive, the interrupt-pending flag follows the state of the external interrupt's input pin. The external interrupt source must hold the input active until the interrupt request is recognized. It must then deactivate the interrupt request before execution of the ISR completes or another interrupt request will be generated. Rev. 1.3 151 C8051F060/1/2/3/4/5/6/7 Interrupt Priority Pending Flag Vector Order Reset 0x0000 Top External Interrupt 0 (/INT0) Timer 0 Overflow External Interrupt 1 (/INT1) Timer 1 Overflow 0x0003 0x000B 0x0013 0x001B 0 1 2 3 UART0 0x0023 4 Timer 2 0x002B 5 Serial Peripheral Interface 0x0033 6 SMBus Interface 0x003B 7 SI (SMB0CN.3) Y 0x0043 8 AD0WINT (ADC0CN.1) Y 0x004B 9 Comparator 0 0x0053 10 Comparator 1 0x005B 11 Comparator 2 0x0063 12 ADC0 End of Conversion 0x006B 13 ADC0INT (ADC0CN.5) Y Timer 3 0x0073 14 TF3 (TMR3CN.7) Y ADC1 End of Conversion 0x007B 15 ADC1INT (ADC1CN.5) Y Timer 4 0x0083 16 TF4 (TMR4CN.7) Y ADC2 Window Comparator 0x008B 17 AD2WINT (ADC2CN.1) Y ADC2 End of Conversion 0x0093 18 AD2INT (ADC2CN.5) Y CAN Interrupt 0x009B 19 CAN0CN.7 Y UART1 0x00A3 20 RI1 (SCON1.0) TI1 (SCON1.1) Y DMA0 Interrupt 0x00AB 21 DMA0INT (DMA0CN.6) Y ADC0 Window Comparator Programmable Counter Array 152 None IE0 (TCON.1) TF0 (TCON.5) IE1 (TCON.3) TF1 (TCON.7) RI0 (SCON0.0) TI0 (SCON0.1) TF2 (TMR2CN.7) SPIF (SPI0CN.7) WCOL (SPI0CN.6) MODF (SPI0CN.5) RXOVRN (SPI0CN.4) CF (PCA0CN.7) CCFn (PCA0CN.n) CP0FIF/CP0RIF (CPT0CN.4/.5) CP1FIF/CP1RIF (CPT1CN.4/.5) CP2FIF/CP2RIF (CPT2CN.4/.5) Rev. 1.3 Cleared by HW Interrupt Source Bit addressable Table 13.4. Interrupt Summary N/A N/A Y Y Y Y Y Y Y Y Enable Flag Priority Control Always Always Enabled Highest EX0 (IE.0) PX0 (IP.0) ET0 (IE.1) PT0 (IP.1) EX1 (IE.2) PX1 (IP.2) ET1 (IE.3) PT1 (IP.3) Y ES0 (IE.4) PS0 (IP.4) Y ET2 (IE.5) PT2 (IP.5) Y ESPI0 (EIE1.0) PSPI0 (EIP1.0) Y Y Y Y ESMB0 (EIE1.1) EWADC0 (EIE1.2) EPCA0 (EIE1.3) CP0IE (EIE1.4) CP1IE (EIE1.5) CP2IE (EIE1.6) EADC0 (EIE1.7) ET3 (EIE2.0) EADC1 (EIE2.1) ET4 (EIE2.2) EWADC2 (EIE2.3) EADC2 (EIE2.4) ECAN0 Y (EIE2.5) ES1 (EIP2.6) EDMA0 (EIE2.7) PSMB0 (EIP1.1) PWADC0 (EIP1.2) PPCA0 (EIP1.3) PCP0 (EIP1.4) PCP1 (EIP1.5) PCP2 (EIP1.6) PADC0 (EIP1.7) PT3 (EIP2.0) PADC1 (EIP2.1) PT4 (EIP2.2) PWADC2 (EIP2.3) PADC2 (EIP2.4) PCAN0 (EIP2.5) PS1 (EIP2.6) PDMA0 (EIP2.7) C8051F060/1/2/3/4/5/6/7 13.3.3. Interrupt Priorities Each interrupt source can be individually programmed to one of two priority levels: low or high. A low priority interrupt service routine can be preempted by a high priority interrupt. A high priority interrupt cannot be preempted. Each interrupt has an associated interrupt priority bit in an SFR (IP-EIP2) used to configure its priority level. Low priority is the default. If two interrupts are recognized simultaneously, the interrupt with the higher priority is serviced first. If both interrupts have the same priority level, a fixed priority order is used to arbitrate, given in Table 13.4. 13.3.4. Interrupt Latency Interrupt response time depends on the state of the CPU when the interrupt occurs. Pending interrupts are sampled and priority decoded each system clock cycle. Therefore, the fastest possible response time is 5 system clock cycles: 1 clock cycle to detect the interrupt and 4 clock cycles to complete the LCALL to the ISR. If an interrupt is pending when a RETI is executed, a single instruction is executed before an LCALL is made to service the pending interrupt. Therefore, the maximum response time for an interrupt (when no other interrupt is currently being serviced or the new interrupt is of greater priority) occurs when the CPU is performing an RETI instruction followed by a DIV as the next instruction. In this case, the response time is 18 system clock cycles: 1 clock cycle to detect the interrupt, 5 clock cycles to execute the RETI, 8 clock cycles to complete the DIV instruction and 4 clock cycles to execute the LCALL to the ISR. If the CPU is executing an ISR for an interrupt with equal or higher priority, the new interrupt will not be serviced until the current ISR completes, including the RETI and following instruction. Rev. 1.3 153 C8051F060/1/2/3/4/5/6/7 13.3.5. Interrupt Register Descriptions The SFRs used to enable the interrupt sources and set their priority level are described below. Refer to the datasheet section associated with a particular on-chip peripheral for information regarding valid interrupt conditions for the peripheral and the behavior of its interrupt-pending flag(s). Figure 13.19. IE: Interrupt Enable R/W R/W R/W R/W R/W R/W R/W R/W Reset Value EA IEGF0 ET2 ES0 ET1 EX1 ET0 EX0 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: 154 Bit Addressable SFR Address: 0xA8 SFR Page: All Pages Bit0 EA: Enable All Interrupts. This bit globally enables/disables all interrupts. It overrides the individual interrupt mask settings. 0: Disable all interrupt sources. 1: Enable each interrupt according to its individual mask setting. IEGF0: General Purpose Flag 0. This is a general purpose flag for use under software control. ET2: Enabler Timer 2 Interrupt. This bit sets the masking of the Timer 2 interrupt. 0: Disable Timer 2 interrupt. 1: Enable interrupt requests generated by the TF2 flag. ES0: Enable UART0 Interrupt. This bit sets the masking of the UART0 interrupt. 0: Disable UART0 interrupt. 1: Enable UART0 interrupt. ET1: Enable Timer 1 Interrupt. This bit sets the masking of the Timer 1 interrupt. 0: Disable all Timer 1 interrupt. 1: Enable interrupt requests generated by the TF1 flag. EX1: Enable External Interrupt 1. This bit sets the masking of external interrupt 1. 0: Disable external interrupt 1. 1: Enable interrupt requests generated by the /INT1 pin. ET0: Enable Timer 0 Interrupt. This bit sets the masking of the Timer 0 interrupt. 0: Disable all Timer 0 interrupt. 1: Enable interrupt requests generated by the TF0 flag. EX0: Enable External Interrupt 0. This bit sets the masking of external interrupt 0. 0: Disable external interrupt 0. 1: Enable interrupt requests generated by the /INT0 pin. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 13.20. IP: Interrupt Priority R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - PT2 PS0 PT1 PX1 PT0 PX0 11000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Bit Addressable SFR Address: 0xB8 SFR Page: All Pages Bit0 UNUSED. Read = 11b, Write = don't care. PT2: Timer 2 Interrupt Priority Control. This bit sets the priority of the Timer 2 interrupt. 0: Timer 2 interrupt set to low priority level. 1: Timer 2 interrupt set to high priority level. PS0: UART0 Interrupt Priority Control. This bit sets the priority of the UART0 interrupt. 0: UART0 interrupt set to low priority level. 1: UART0 interrupt set to high priority level. PT1: Timer 1 Interrupt Priority Control. This bit sets the priority of the Timer 1 interrupt. 0: Timer 1 interrupt set to low priority level. 1: Timer 1 interrupt set to high priority level. PX1: External Interrupt 1 Priority Control. This bit sets the priority of the External Interrupt 1 interrupt. 0: External Interrupt 1 set to low priority level. 1: External Interrupt 1 set to high priority level. PT0: Timer 0 Interrupt Priority Control. This bit sets the priority of the Timer 0 interrupt. 0: Timer 0 interrupt set to low priority level. 1: Timer 0 interrupt set to high priority level. PX0: External Interrupt 0 Priority Control. This bit sets the priority of the External Interrupt 0 interrupt. 0: External Interrupt 0 set to low priority level. 1: External Interrupt 0 set to high priority level. Rev. 1.3 155 C8051F060/1/2/3/4/5/6/7 Figure 13.21. EIE1: Extended Interrupt Enable 1 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value EADC0 CP2IE CP1IE CP0IE EPCA0 EWADC0 ESMB0 ESPI0 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit6: Bit6: Bit3: Bit2: Bit1: Bit0: 156 Bit0 SFR Address: 0xE6 SFR Page: All Pages EADC0: Enable ADC0 End of Conversion Interrupt. This bit sets the masking of the ADC0 End of Conversion Interrupt. 0: Disable ADC0 Conversion Interrupt. 1: Enable interrupt requests generated by the ADC1 Conversion Interrupt. CP2IE: Enable Comparator (CP2) Interrupt. This bit sets the masking of the CP2 interrupt. 0: Disable CP2 interrupts. 1: Enable interrupt requests generated by the CP2IF flag. CP1IE: Enable Comparator (CP1) Interrupt. This bit sets the masking of the CP1 interrupt. 0: Disable CP1 interrupts. 1: Enable interrupt requests generated by the CP1IF flag. CP0IE: Enable Comparator (CP0) Interrupt. This bit sets the masking of the CP0 interrupt. 0: Disable CP0 interrupts. 1: Enable interrupt requests generated by the CP0IF flag. EPCA0: Enable Programmable Counter Array (PCA0) Interrupt. This bit sets the masking of the PCA0 interrupts. 0: Disable all PCA0 interrupts. 1: Enable interrupt requests generated by PCA0. EWADC0: Enable Window Comparison ADC0 Interrupt. This bit sets the masking of ADC0 Window Comparison interrupt. 0: Disable ADC0 Window Comparison Interrupt. 1: Enable Interrupt requests generated by ADC0 Window Comparisons. ESMB0: Enable System Management Bus (SMBus0) Interrupt. This bit sets the masking of the SMBus interrupt. 0: Disable all SMBus interrupts. 1: Enable interrupt requests generated by the SI flag. ESPI0: Enable Serial Peripheral Interface (SPI0) Interrupt. This bit sets the masking of SPI0 interrupt. 0: Disable all SPI0 interrupts. 1: Enable Interrupt requests generated by the SPI0 flag. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 13.22. EIE2: Extended Interrupt Enable 2 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value EDMA0 ES1 ECAN0 EADC2 EWADC2 ET4 EADC1 ET3 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Bit0 SFR Address: 0xE7 SFR Page: All Pages EDMA0: Enable DMA0 Interrupt. This bit sets the masking of the DMA0 Interrupt. 0: Disable DMA0 interrupt. 1: Enable DMA0 interrupt. ES1: Enable UART1 Interrupt. This bit sets the masking of the UART1 Interrupt. 0: Disable UART1 interrupt. 1: Enable UART1 interrupt. ECAN0: Enable CAN Controller Interrupt. This bit sets the masking of the CAN Controller Interrupt. 0: Disable CAN Controller Interrupt. 1: Enable interrupt requests generated by the CAN Controller. EADC2: Enable ADC2 End Of Conversion Interrupt. This bit sets the masking of the ADC2 End of Conversion interrupt. 0: Disable ADC2 End of Conversion interrupt. 1: Enable interrupt requests generated by the ADC2 End of Conversion Interrupt. EWADC2: Enable Window Comparison ADC1 Interrupt. This bit sets the masking of ADC2 Window Comparison interrupt. 0: Disable ADC2 Window Comparison Interrupt. 1: Enable Interrupt requests generated by ADC2 Window Comparisons. ET4: Enable Timer 4 Interrupt This bit sets the masking of the Timer 4 interrupt. 0: Disable Timer 4 interrupt. 1: Enable interrupt requests generated by the TF4 flag. EADC1: Enable ADC1 End of Conversion Interrupt. This bit sets the masking of the ADC1 End of Conversion Interrupt. 0: Disable ADC1 Conversion Interrupt. 1: Enable interrupt requests generated by the ADC1 Conversion Interrupt. ET3: Enable Timer 3 Interrupt. This bit sets the masking of the Timer 3 interrupt. 0: Disable all Timer 3 interrupts. 1: Enable interrupt requests generated by the TF3 flag. Rev. 1.3 157 C8051F060/1/2/3/4/5/6/7 Figure 13.23. EIP1: Extended Interrupt Priority 1 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value PADC0 PCP2 PCP1 PCP0 PPCA0 PWADC0 PSMB0 PSPI0 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: 158 Bit0 SFR Address: 0xF6 SFR Page: All Pages PADC0: ADC End of Conversion Interrupt Priority Control. This bit sets the priority of the ADC0 End of Conversion Interrupt. 0: ADC0 End of Conversion interrupt set to low priority level. 1: ADC0 End of Conversion interrupt set to high priority level. PCP2: Comparator2 (CP2) Interrupt Priority Control. This bit sets the priority of the CP2 interrupt. 0: CP2 interrupt set to low priority level. 1: CP2 interrupt set to high priority level. PCP1: Comparator1 (CP1) Interrupt Priority Control. This bit sets the priority of the CP1 interrupt. 0: CP1 interrupt set to low priority level. 1: CP1 interrupt set to high priority level. PCP0: Comparator0 (CP0) Interrupt Priority Control. This bit sets the priority of the CP0 interrupt. 0: CP0 interrupt set to low priority level. 1: CP0 interrupt set to high priority level. PPCA0: Programmable Counter Array (PCA0) Interrupt Priority Control. This bit sets the priority of the PCA0 interrupt. 0: PCA0 interrupt set to low priority level. 1: PCA0 interrupt set to high priority level. PWADC0: ADC0 Window Comparator Interrupt Priority Control. This bit sets the priority of the ADC0 Window interrupt. 0: ADC0 Window interrupt set to low priority level. 1: ADC0 Window interrupt set to high priority level. PSMB0: System Management Bus (SMBus0) Interrupt Priority Control. This bit sets the priority of the SMBus0 interrupt. 0: SMBus interrupt set to low priority level. 1: SMBus interrupt set to high priority level. PSPI0: Serial Peripheral Interface (SPI0) Interrupt Priority Control. This bit sets the priority of the SPI0 interrupt. 0: SPI0 interrupt set to low priority level. 1: SPI0 interrupt set to high priority level. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 13.24. EIP2: Extended Interrupt Priority 2 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value PDMA0 PS1 PCAN0 PADC2 PWADC2 PT4 PADC1 PT3 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Bit0 SFR Address: 0xF7 SFR Page: All Pages PDMA0: DMA0 Interrupt Priority Control. This bit sets the priority of the DMA0 interrupt. 0: DMA0 interrupt set to low priority. 1: DMA0 interrupt set to high priority. PS1: UART1 Interrupt Priority Control. This bit sets the priority of the UART1 interrupt. 0: UART1 interrupt set to low priority. 1: UART1 interrupt set to high priority. PCAN0: CAN Interrupt Priority Control. This bit sets the priority of the CAN Interrupt. 0: CAN Interrupt set to low priority level. 1: CAN Interrupt set to high priority level. PADC2: ADC2 End Of Conversion Interrupt Priority Control. This bit sets the priority of the ADC2 End of Conversion interrupt. 0: ADC2 End of Conversion interrupt set to low priority. 1: ADC2 End of Conversion interrupt set to high priority. PWADC2: ADC2 Window Comparator Interrupt Priority Control. 0: ADC2 Window interrupt set to low priority. 1: ADC2 Window interrupt set to high priority. PT4: Timer 4 Interrupt Priority Control. This bit sets the priority of the Timer 4 interrupt. 0: Timer 4 interrupt set to low priority. 1: Timer 4 interrupt set to high priority. PADC1: ADC End of Conversion Interrupt Priority Control. This bit sets the priority of the ADC1 End of Conversion Interrupt. 0: ADC1 End of Conversion interrupt set to low priority level. 1: ADC1 End of Conversion interrupt set to high priority level. PT3: Timer 3 Interrupt Priority Control. This bit sets the priority of the Timer 3 interrupts. 0: Timer 3 interrupt set to low priority level. 1: Timer 3 interrupt set to high priority level. Rev. 1.3 159 C8051F060/1/2/3/4/5/6/7 13.4. Power Management Modes The CIP-51 core has two software programmable power management modes: Idle and Stop. Idle mode halts the CPU while leaving the external peripherals and internal clocks active. In Stop mode, the CPU is halted, all interrupts and timers (except the Missing Clock Detector) are inactive, and the internal oscillator is stopped. Since clocks are running in Idle mode, power consumption is dependent upon the system clock frequency and the number of peripherals left in active mode before entering Idle. Stop mode consumes the least power. Figure 13.25 describes the Power Control Register (PCON) used to control the CIP-51's power management modes. Although the CIP-51 has Idle and Stop modes built in (as with any standard 8051 architecture), power management of the entire MCU is better accomplished by enabling/disabling individual peripherals as needed. Each analog peripheral can be disabled when not in use and put into low power mode. Digital peripherals, such as timers or serial buses, draw little power whenever they are not in use. Turning off the oscillator saves even more power, but requires a reset to restart the MCU. 13.4.1. Idle Mode Setting the Idle Mode Select bit (PCON.0) causes the CIP-51 to halt the CPU and enter Idle mode as soon as the instruction that sets the bit completes. All internal registers and memory maintain their original data. All analog and digital peripherals can remain active during Idle mode. Idle mode is terminated when an enabled interrupt or /RST is asserted. The assertion of an enabled interrupt will cause the Idle Mode Selection bit (PCON.0) to be cleared and the CPU to resume operation. The pending interrupt will be serviced and the next instruction to be executed after the return from interrupt (RETI) will be the instruction immediately following the one that set the Idle Mode Select bit. If Idle mode is terminated by an internal or external reset, the CIP-51 performs a normal reset sequence and begins program execution at address 0x0000. If enabled, the WDT will eventually cause an internal watchdog reset and thereby terminate the Idle mode. This feature protects the system from an unintended permanent shutdown in the event of an inadvertent write to the PCON register. If this behavior is not desired, the WDT may be disabled by software prior to entering the Idle mode if the WDT was initially configured to allow this operation. This provides the opportunity for additional power savings, allowing the system to remain in the Idle mode indefinitely, waiting for an external stimulus to wake up the system. Refer to Section 14.7 for more information on the use and configuration of the WDT. Note: Any instruction which sets the IDLE bit should be immediately followed by an instruction which has two or more opcode bytes.For example: // in ‘C’: PCON |= 0x01; PCON = PCON; // Set IDLE bit // ... Followed by a 3-cycle Dummy Instruction ; in assembly: ORL PCON, #01h MOV PCON, PCON ; Set IDLE bit ; ... Followed by a 3-cycle Dummy Instruction If the instruction following the write to the IDLE bit is a single-byte instruction and an interrupt occurs during the execution of the instruction of the instruction which sets the IDLE bit, the CPU may not wake from IDLE mode when a future interrupt occurs. 160 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 13.4.2. Stop Mode Setting the Stop Mode Select bit (PCON.1) causes the CIP-51 to enter Stop mode as soon as the instruction that sets the bit completes. In Stop mode, the CPU and internal oscillators are stopped, effectively shutting down all digital peripherals. Each analog peripheral must be shut down individually prior to entering Stop Mode. Stop mode can only be terminated by an internal or external reset. On reset, the CIP-51 performs the normal reset sequence and begins program execution at address 0x0000. If enabled, the Missing Clock Detector will cause an internal reset and thereby terminate the Stop mode. The Missing Clock Detector should be disabled if the CPU is to be put to sleep for longer than the MCD timeout of 100 μs. Figure 13.25. PCON: Power Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - - - - - STOP IDLE 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-2: Bit1: Bit0: Bit0 SFR Address: 0x87 SFR Page: All Pages Reserved. STOP: STOP Mode Select. Writing a ‘1’ to this bit will place the CIP-51 into STOP mode. This bit will always read ‘0’. 1: CIP-51 forced into power-down mode. (Turns off internal oscillator). IDLE: IDLE Mode Select. Writing a ‘1’ to this bit will place the CIP-51 into IDLE mode. This bit will always read ‘0’. 1: CIP-51 forced into IDLE mode. (Shuts off clock to CPU, but clock to Timers, Interrupts, and all peripherals remain active.) See Note in Section “13.4.1. Idle Mode” on page 160. Rev. 1.3 161 C8051F060/1/2/3/4/5/6/7 162 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 14. Reset Sources Reset circuitry allows the controller to be easily placed in a predefined default condition. On entry to this reset state, the following occur: • • • • CIP-51 halts program execution Special Function Registers (SFRs) are initialized to their defined reset values External port pins are forced to a known configuration Interrupts and timers are disabled. All SFRs are reset to the predefined values noted in the SFR detailed descriptions. The contents of internal data memory are unaffected during a reset; any previously stored data is preserved. However, since the stack pointer SFR is reset, the stack is effectively lost even though the data on the stack are not altered. The I/O port latches are reset to 0xFF (all logic 1’s), activating internal weak pull-ups which take the external I/O pins to a high state. The external I/O pins do not go high immediately, but will go high within four system clock cycles after entering the reset state. This allows power to be conserved while the part is held in reset. For VDD Monitor resets, the /RST pin is driven low until the end of the VDD reset timeout. On exit from the reset state, the program counter (PC) is reset, and the system clock defaults to the internal oscillator running at its lowest frequency. Refer to Section “15. Oscillators” on page 171 for information on selecting and configuring the system clock source. The Watchdog Timer is enabled using its longest timeout interval (see Section “14.7. Watchdog Timer Reset” on page 165). Once the system clock source is stable, program execution begins at location 0x0000. There are seven sources for putting the MCU into the reset state: power-on, power-fail, external /RST pin, external CNVSTR2 signal, software command, Comparator0, Missing Clock Detector, and Watchdog Timer. Each reset source is described in the following sections. Figure 14.1. Reset Sources Rev. 1.3 163 C8051F060/1/2/3/4/5/6/7 14.1. Power-on Reset The C8051F060/1/2/3/4/5/6/7 family incorporates a power supply monitor that holds the MCU in the reset state until VDD rises above the VRST level during power-up. See Figure 14.2 for timing diagram, and refer to Table 14.1 for the Electrical Characteristics of the power supply monitor circuit. The /RST pin is asserted low until the end of the 100 ms VDD Monitor timeout in order to allow the VDD supply to stabilize. The VDD Monitor reset is enabled and disabled using the external VDD monitor enable pin (MONEN). On exit from a power-on reset, the PORSF flag (RSTSRC.1) is set by hardware to logic 1. All of the other reset flags in the RSTSRC Register are indeterminate. PORSF is cleared by all other resets. Since all resets cause program execution to begin at the same location (0x0000) software can read the PORSF flag to determine if a power-up was the cause of reset. The contents of internal data memory should be assumed to be undefined after a power-on reset. Figure 14.2. Reset Timing 14.2. Power-fail Reset When a power-down transition or power irregularity causes VDD to drop below VRST, the power supply monitor will drive the /RST pin low and return the CIP-51 to the reset state. When VDD returns to a level above VRST, the CIP-51 will leave the reset state in the same manner as that for the power-on reset (see Figure 14.2). Note that even though internal data memory contents are not altered by the power-fail reset, it is impossible to determine if VDD dropped below the level required for data retention. If the PORSF flag is set to logic 1, the data may no longer be valid. 14.3. External Reset The external /RST pin provides a means for external circuitry to force the MCU into a reset state. Asserting the /RST pin low will cause the MCU to enter the reset state. It may be desirable to provide an external pull-up and/or decoupling of the /RST pin to avoid erroneous noise-induced resets. The MCU will remain in 164 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 reset until at least 12 clock cycles after the active-low /RST signal is removed. The PINRSF flag (RSTSRC.0) is set on exit from an external reset. 14.4. Missing Clock Detector Reset The Missing Clock Detector is essentially a one-shot circuit that is triggered by the MCU system clock. If the system clock goes away for more than 100 μs, the one-shot will time out and generate a reset. After a Missing Clock Detector reset, the MCDRSF flag (RSTSRC.2) will be set, signifying the MSD as the reset source; otherwise, this bit reads ‘0’. The state of the /RST pin is unaffected by this reset. Setting the MCDRSF bit, RSTSRC.2 (see Section “15. Oscillators” on page 171) enables the Missing Clock Detector. 14.5. Comparator0 Reset Comparator0 can be configured as a reset input by writing a ‘1’ to the C0RSEF flag (RSTSRC.5). Comparator0 should be enabled using CPT0CN.7 (see Section “12. Comparators” on page 117) prior to writing to C0RSEF to prevent any turn-on chatter on the output from generating an unwanted reset. The Comparator0 reset is active-low: if the non-inverting input voltage (CP0+ pin) is less than the inverting input voltage (CP0- pin), the MCU is put into the reset state. After a Comparator0 Reset, the C0RSEF flag (RSTSRC.5) will read ‘1’ signifying Comparator0 as the reset source; otherwise, this bit reads ‘0’. The state of the /RST pin is unaffected by this reset. 14.6. External CNVSTR2 Pin Reset The external CNVSTR2 signal can be configured as a reset input by writing a ‘1’ to the CNVRSEF flag (RSTSRC.6). The CNVSTR2 signal can appear on any of the P0, P1, P2 or P3 I/O pins as described in Section “18.1. Ports 0 through 3 and the Priority Crossbar Decoder” on page 205. Note that the Crossbar must be configured for the CNVSTR2 signal to be routed to the appropriate Port I/O. The Crossbar should be configured and enabled before the CNVRSEF is set. CNVSTR2 cannot be used to start ADC2 conversions when it is configured as a reset source. When configured as a reset, CNVSTR2 is active-low and level sensitive. After a CNVSTR2 reset, the CNVRSEF flag (RSTSRC.6) will read ‘1’ signifying CNVSTR2 as the reset source; otherwise, this bit reads ‘0’. The state of the /RST pin is unaffected by this reset. 14.7. Watchdog Timer Reset The MCU includes a programmable Watchdog Timer (WDT) running off the system clock. A WDT overflow will force the MCU into the reset state. To prevent the reset, the WDT must be restarted by application software before overflow. If the system experiences a software or hardware malfunction preventing the software from restarting the WDT, the WDT will overflow and cause a reset. This should prevent the system from running out of control. Following a reset the WDT is automatically enabled and running with the default maximum time interval. If desired the WDT can be disabled by system software or locked on to prevent accidental disabling. Once locked, the WDT cannot be disabled until the next system reset. The state of the /RST pin is unaffected by this reset. The WDT consists of a 21-bit timer running from the programmed system clock. The timer measures the period between specific writes to its control register. If this period exceeds the programmed limit, a WDT reset is generated. The WDT can be enabled and disabled as needed in software, or can be permanently enabled if desired. Watchdog features are controlled via the Watchdog Timer Control Register (WDTCN) shown in Figure 14.3. Rev. 1.3 165 C8051F060/1/2/3/4/5/6/7 14.7.1. Enable/Reset WDT The watchdog timer is both enabled and reset by writing 0xA5 to the WDTCN register. The user's application software should include periodic writes of 0xA5 to WDTCN as needed to prevent a watchdog timer overflow. The WDT is enabled and reset as a result of any system reset. 14.7.2. Disable WDT Writing 0xDE followed by 0xAD to the WDTCN register disables the WDT. The following code segment illustrates disabling the WDT: CLR MOV MOV SETB EA WDTCN,#0DEh WDTCN,#0ADh EA ; disable all interrupts ; disable software watchdog timer ; re-enable interrupts The writes of 0xDE and 0xAD must occur within 4 clock cycles of each other, or the disable operation is ignored. Interrupts should be disabled during this procedure to avoid delay between the two writes. 14.7.3. Disable WDT Lockout Writing 0xFF to WDTCN locks out the disable feature. Once locked out, the disable operation is ignored until the next system reset. Writing 0xFF does not enable or reset the watchdog timer. Applications always intending to use the watchdog should write 0xFF to WDTCN in the initialization code. 14.7.4. Setting WDT Interval WDTCN.[2:0] control the watchdog timeout interval. The interval is given by the following equation: 4 3 + WDTCN  2 – 0  166  T sysclk ; where Tsysclk is the system clock period. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 For a 3 MHz system clock, this provides an interval range of 0.021 ms to 349.5 ms. WDTCN.7 must be logic 0 when setting this interval. Reading WDTCN returns the programmed interval. WDTCN.[2:0] reads 111b after a system reset. Figure 14.3. WDTCN: Watchdog Timer Control Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value xxxxx111 Bits7-0: Bit4: Bits2-0: Bit0 SFR Address: 0xFF SFR Page: All Pages WDT Control. Writing 0xA5 both enables and reloads the WDT. Writing 0xDE followed within 4 system clocks by 0xAD disables the WDT. Writing 0xFF locks out the disable feature. Watchdog Status Bit (when Read). Reading the WDTCN.[4] bit indicates the Watchdog Timer Status. 0: WDT is inactive. 1: WDT is active. Watchdog Timeout Interval Bits. The WDTCN.[2:0] bits set the Watchdog Timeout Interval. When writing these bits, WDTCN.7 must be set to 0. Rev. 1.3 167 C8051F060/1/2/3/4/5/6/7 Figure 14.4. RSTSRC: Reset Source Register R R/W R/W R/W R R/W R/W R/W Reset Value - CNVRSEF C0RSEF SWRSEF WDTRSF MCDRSF PORSF PINRSF 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: 168 Bit0 SFR Address: 0xEF SFR Page: 0 Reserved. CNVRSEF: Convert Start Reset Source Enable and Flag Write: 0: CNVSTR2 is not a reset source. 1: CNVSTR2 is a reset source (active low). Read: 0: Source of prior reset was not CNVSTR2. 1: Source of prior reset was CNVSTR2. C0RSEF: Comparator0 Reset Enable and Flag. Write: 0: Comparator0 is not a reset source. 1: Comparator0 is a reset source (active low). Read: 0: Source of last reset was not Comparator0. 1: Source of last reset was Comparator0. SWRSF: Software Reset Force and Flag. Write: 0: No effect. 1: Forces an internal reset. /RST pin is not effected. Read: 0: Source of last reset was not a write to the SWRSF bit. 1: Source of last reset was a write to the SWRSF bit. WDTRSF: Watchdog Timer Reset Flag. 0: Source of last reset was not WDT timeout. 1: Source of last reset was WDT timeout. MCDRSF: Missing Clock Detector Flag. Write: 0: Missing Clock Detector disabled. 1: Missing Clock Detector enabled; triggers a reset if a missing clock condition is detected. Read: 0: Source of last reset was not a Missing Clock Detector timeout. 1: Source of last reset was a Missing Clock Detector timeout. PORSF: Power-On Reset Flag. Write: If the VDD monitor circuitry is enabled (by tying the MONEN pin to a logic high state), this bit can be written to select or de-select the VDD monitor as a reset source. 0: De-select the VDD monitor as a reset source. 1: Select the VDD monitor as a reset source. Important: At power-on, the VDD monitor is enabled/disabled using the external VDD monitor enable pin (MONEN). The PORSF bit does not disable or enable the VDD monitor circuit. It simply selects the VDD monitor as a reset source. Read: This bit is set whenever a power-on reset occurs. This may be due to a true power-on reset or a VDD monitor reset. In either case, data memory should be considered indeterminate following the reset. 0: Source of last reset was not a power-on or VDD monitor reset. 1: Source of last reset was a power-on or VDD monitor reset. Note: When this flag is read as '1', all other reset flags are indeterminate. PINRSF: HW Pin Reset Flag. Write: 0: No effect. 1: Forces a Power-On Reset. /RST is driven low. Read: 0: Source of prior reset was not /RST pin. 1: Source of prior reset was /RST pin. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Table 14.1. Reset Electrical Characteristics -40 to +85 °C unless otherwise specified. Parameter Conditions IOL = 8.5 mA, VDD = 2.7 V to 3.6 V /RST Output Low Voltage Min /RST Input High Voltage 0.7 x VDD Typ Reset Time Delay Missing Clock Detector Timeout Units V V 0.3 x VDD /RST Input Low Voltage /RST Input Leakage Current VDD for /RST Output Valid AV+ for /RST Output Valid VDD POR Threshold (VRST) Minimum /RST Low Time to Generate a System Reset Max 0.6 /RST = 0.0 V 50 1.0 1.0 2.40 2.55 2.70 10 /RST rising edge after VDD crosses VRST threshold Time from last system clock to reset initiation Rev. 1.3 μA V V V ns 80 100 120 ms 100 220 500 μs 169 C8051F060/1/2/3/4/5/6/7 170 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 15. Oscillators C8051F060/1/2/3/4/5/6/7 devices include a programmable internal oscillator and an external oscillator drive circuit. The internal oscillator can be enabled, disabled and calibrated using the OSCICN and OSCICL registers, as shown in Figure 15.1. The system clock can be sourced by the external oscillator circuit, the internal oscillator, or a scaled version of the internal oscillator. The internal oscillator's electrical specifications are given in Table 15.1. Figure 15.1. Oscillator Diagram 15.1. Programmable Internal Oscillator All C8051F060/1/2/3/4/5/6/7 devices include a programmable internal oscillator that defaults as the system clock after a system reset. The internal oscillator period can be adjusted via the OSCICL register as defined by Figure 15.2. OSCICL is factory calibrated to obtain a 24.5 MHz base frequency (fBASE). Electrical specifications for the precision internal oscillator are given in Table 15.1. The programmed internal oscillator frequency must not exceed 25 MHz. Note that the system clock may be derived from the programmed internal oscillator divided by 1, 2, 4, or 8, as defined by the IFCN bits in register OSCICN. Rev. 1.3 171 C8051F060/1/2/3/4/5/6/7 . Figure 15.2. OSCICL: Internal Oscillator Calibration Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value Variable Bit0 SFR Address: 0x8B SFR Page: F Bits 7-0: OSCICL: Internal Oscillator Calibration Register This register calibrates the internal oscillator period. The reset value for OSCICL defines the internal oscillator base frequency. The reset value is factory calibrated to generate an internal oscillator frequency of 24.5 MHz. Figure 15.3. OSCICN: Internal Oscillator Control Register R/W R R/W R R/W R/W R/W R/W Reset Value IOSCEN IFRDY - - - - IFCN1 IFCN0 11000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bits5-2: Bits1-0: 172 IOSCEN: Internal Oscillator Enable Bit 0: Internal Oscillator Disabled 1: Internal Oscillator Enabled IFRDY: Internal Oscillator Frequency Ready Flag 0: Internal Oscillator not running at programmed frequency. 1: Internal Oscillator running at programmed frequency. Reserved. IFCN1-0: Internal Oscillator Frequency Control Bits 00: SYSCLK derived from Internal Oscillator divided by 8. 01: SYSCLK derived from Internal Oscillator divided by 4. 10: SYSCLK derived from Internal Oscillator divided by 2. 11: SYSCLK derived from Internal Oscillator divided by 1. Rev. 1.3 Bit0 SFR Address: 0x8A SFR Page: F C8051F060/1/2/3/4/5/6/7 Table 15.1. Internal Oscillator Electrical Characteristics -40°C to +85°C unles otherwise specified. Parameter Conditions Calibrated Internal Oscillator Frequency Internal Oscillator Supply OSCICN.7 = 1 Current (3.0V Supply) Min Typ Max Units 24 24.5 25 MHz 550 μA 15.2. External Oscillator Drive Circuit The external oscillator circuit may drive an external crystal, ceramic resonator, capacitor, or RC network. A CMOS clock may also provide a clock input. For a crystal or ceramic resonator configuration, the crystal/ resonator must be wired across the XTAL1 and XTAL2 pins as shown in Option 1 of Figure 15.1. In RC, capacitor, or CMOS clock configuration, the clock source should be wired to the XTAL2 and/or XTAL1 pin(s) as shown in Option 2, 3, or 4 of Figure 15.1. The type of external oscillator must be selected in the OSCXCN register, and the frequency control bits (XFCN) must be selected appropriately (see Figure 15.5). 15.3. System Clock Selection The CLKSL bit in register CLKSEL selects which oscillator generates the system clock. CLKSL must be set to ‘1’ for the system clock to run from the external oscillator; however the external oscillator may still clock peripherals (timers, PCA) when the internal oscillator is selected as the system clock. The system clock may be switched on-the-fly between the internal and external oscillator, so long as the selected oscillator is enabled and settled. The internal oscillator requires little start-up time, and may be enabled and selected as the system clock in the same write to OSCICN. External crystals and ceramic resonators typically require a start-up time before they are settled and ready for use as the system clock. The Crystal Valid Flag (XTLVLD in register OSCXCN) is set to ‘1’ by hardware when the external oscillator is settled. To avoid reading a false XTLVLD, in crystal mode software should delay at least 1 ms between enabling the external oscillator and checking XTLVLD. RC and C modes typically require no startup time. Figure 15.4. CLKSEL: Oscillator Clock Selection Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - - - - - - CLKSL 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-1: Bit0: Bit0 SFR Address: 0x97 SFR Page: F Reserved. CLKSL: System Clock Source Select Bit. 0: SYSCLK derived from the Internal Oscillator, and scaled as per the IFCN bits in OSCICN. 1: SYSCLK derived from the External Oscillator circuit. Rev. 1.3 173 C8051F060/1/2/3/4/5/6/7 Figure 15.5. OSCXCN: External Oscillator Control Register R XTLVLD Bit7 Bit7: Bits6-4: Bit3: Bits2-0: R/W R/W R/W XOSCMD2 XOSCMD1 XOSCMD0 Bit6 Bit5 Bit4 R R/W R/W R/W Reset Value - XFCN2 XFCN1 XFCN0 00000000 Bit3 Bit2 Bit1 XTLVLD: Crystal Oscillator Valid Flag. (Valid only when XOSCMD = 11x.). 0: Crystal Oscillator is unused or not yet stable. 1: Crystal Oscillator is running and stable. XOSCMD2-0: External Oscillator Mode Bits. 00x: External Oscillator circuit off. 010: External CMOS Clock Mode (External CMOS Clock input on XTAL1 pin). 011: External CMOS Clock Mode with divide by 2 stage (External CMOS Clock input on XTAL1 pin). 10x: RC/C Oscillator Mode with divide by 2 stage. 110: Crystal Oscillator Mode. 111: Crystal Oscillator Mode with divide by 2 stage. Unused. Read = 0, Write = don't care. XFCN2-0: External Oscillator Frequency Control Bits. 000-111: see table below: XFCN 000 001 010 011 100 101 110 111 Crystal (XOSCMD = 11x) f  32 kHz 32 kHz f 84 kHz 84 kHz  f 225 kHz 225 kHz  f 590 kHz 590 kHz  f 1.5 MHz 1.5 MHz  f 4 MHz 4 MHz  f 10 MHz 10 MHz  f 30 MHz RC (XOSCMD = 10x) f 25 kHz 25 kHz f 50 kHz 50 kHz f 100 kHz 100 kHz f 200 kHz 200 kHz f 400 kHz 400 kHz f 800 kHz 800 kHz f 1.6 MHz 1.6 MHz f 3.2 MHz CRYSTAL MODE (Circuit from Figure 15.1, Option 1; XOSCMD = 11x). Choose XFCN value to match crystal frequency. RC MODE (Circuit from Figure 15.1, Option 2; XOSCMD = 10x). Choose XFCN value to match frequency range: f = 1.23(103) / (R * C), where f = frequency of oscillation in MHz C = capacitor value in pF R = Pull-up resistor value in k C MODE (Circuit from Figure 15.1, Option 3; XOSCMD = 10x). Choose K Factor (KF) for the oscillation frequency desired: f = KF / (C * VDD), where f = frequency of oscillation in MHz C = capacitor value on XTAL1, XTAL2 pins in pF VDD = Power Supply on MCU in volts 174 Bit0 SFR Address: 0x8C SFR Page: F Rev. 1.3 C (XOSCMD = 10x) K Factor = 0.87 K Factor = 2.6 K Factor = 7.7 K Factor = 22 K Factor = 65 K Factor = 180 K Factor = 664 K Factor = 1590 C8051F060/1/2/3/4/5/6/7 15.4. External Crystal Example If a crystal or ceramic resonator is used as an external oscillator source for the MCU, the circuit should be configured as shown in Figure 15.1, Option 1. The External Oscillator Frequency Control value (XFCN) should be chosen from the Crystal column of the table in Figure 15.5 (OSCXCN register). For example, an 11.0592 MHz crystal requires an XFCN setting of 111b. When the crystal oscillator is enabled, the oscillator amplitude detection circuit requires a settle time to achieve proper bias. Introducing a blanking interval of at least 1 ms between enabling the oscillator and checking the XTLVLD bit will prevent a premature switch to the external oscillator as the system clock. Switching to the external oscillator before the crystal oscillator has stabilized can result in unpredictable behavior. The recommended procedure is: Step 1. Step 2. Step 3. Step 4. Enable the external oscillator. Wait at least1 ms. Poll for XTLVLD => ‘1’. Switch the system clock to the external oscillator. Important Note on External Crystals: Crystal oscillator circuits are quite sensitive to PCB layout and external noise. The crystal should be placed as close as possible to the XTAL pins on the device. The traces should be as short as possible and shielded with ground plane from any other traces which could introduce noise or interference. Crystal loading capacitors should be referenced to AGND. 15.5. External RC Example If an RC network is used as an external oscillator source for the MCU, the circuit should be configured as shown in Figure 15.1, Option 2. The capacitor should be no greater than 100 pF; however for very small capacitors, the total capacitance may be dominated by parasitic capacitance in the PCB layout. To determine the required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register, first select the RC network value to produce the desired frequency of oscillation. If the frequency desired is 100 kHz, let R = 246 k and C = 50 pF: f = 1.23( 103 ) / RC = 1.23 ( 103 ) / [ 246 * 50 ] = 0.1 MHz = 100 kHz Referring to the table in Figure 15.5, the required XFCN setting is 010. 15.6. External Capacitor Example If a capacitor is used as an external oscillator for the MCU, the circuit should be configured as shown in Figure 15.1, Option 3. The capacitor should be no greater than 100 pF; however for very small capacitors, the total capacitance may be dominated by parasitic capacitance in the PCB layout. To determine the required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register, select the capacitor to be used and find the frequency of oscillation from the equations below. Assume VDD = 3.0 V and C = 50 pF: f = KF / ( C * VDD ) = KF / ( 50 * 3 ) f = KF / 150 If a frequency of roughly 50 kHz is desired, select the K Factor from the table in Figure 15.5 as KF = 7.7: f = 7.7 / 150 = 0.051 MHz, or 51 kHz Therefore, the XFCN value to use in this example is 010. Rev. 1.3 175 C8051F060/1/2/3/4/5/6/7 176 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 16. Flash Memory The C8051F060/1/2/3/4/5/6/7 devices include on-chip, reprogrammable Flash memory for program code and non-volatile data storage. The C8051F060/1/2/3/4/5 include 64 k + 128 bytes of Flash, and the C8051F066/7 include 32 k + 128 bytes of Flash. The Flash memory can be programmed in-system, a single byte at a time, through the JTAG interface or by software using the MOVX write instructions. Once cleared to logic 0, a Flash bit must be erased to set it back to logic 1. The bytes would typically be erased (set to 0xFF) before being reprogrammed. Flash write and erase operations are automatically timed by hardware for proper execution; data polling to determine the end of the write/erase operation is not required. The CPU is stalled during write/erase operations while the device peripherals remain active. Interrupts that occur during Flash write/erase operations are held, and are then serviced in their priority order once the Flash operation has completed. Refer to Table 16.1 for the electrical characteristics of the Flash memory. 16.1. Programming The Flash Memory The simplest means of programming the Flash memory is through the JTAG interface using programming tools provided by Silicon Labs or a third party vendor. This is the only means for programming a non-initialized device. For details on the JTAG commands to program Flash memory, see Section “26. JTAG (IEEE 1149.1)” on page 317. The Flash memory can be programmed from software using the MOVX write instruction with the address and data byte to be programmed provided as normal operands. Before writing to Flash memory using MOVX, Flash write operations must be enabled by setting the PSWE Program Store Write Enable bit (PSCTL.0) to logic 1. This directs the MOVX writes to Flash memory instead of to XRAM, which is the default target. The PSWE bit remains set until cleared by software. To avoid errant Flash writes, it is recommended that interrupts be disabled while the PSWE bit is logic 1. Flash memory is read using the MOVC instruction. MOVX reads are always directed to XRAM, regardless of the state of PSWE. NOTE: To ensure the integrity of Flash memory contents, it is strongly recommended that the onchip VDD monitor be enabled by connecting the VDD monitor enable pin (MONEN) to VDD and setting the PORSF bit in the RSTSRC register to ‘1’ in any system that writes and/or erases Flash memory from software. See “Reset Sources” on page 163 for more information. A write to Flash memory can clear bits but cannot set them; only an erase operation can set bits in Flash. A byte location to be programmed must be erased before a new value can be written. The Flash memory is organized in 512-byte pages. The erase operation applies to an entire page (setting all bytes in the page to 0xFF). The following steps illustrate the algorithm for programming Flash from user software. Step 1. Disable interrupts. Step 2. Set FLWE (FLSCL.0) to enable Flash writes/erases via user software. Step 3. Set PSEE (PSCTL.1) to enable Flash erases. Step 4. Set PSWE (PSCTL.0) to redirect MOVX commands to write to Flash. Step 5. Use the MOVX command to write a data byte to any location within the 512-byte page to be erased. Step 6. Clear PSEE to disable Flash erases Step 7. Use the MOVX command to write a data byte to the desired byte location within the erased 512-byte page. Repeat this step until all desired bytes are written (within the target page). Rev. 1.3 177 C8051F060/1/2/3/4/5/6/7 Step 8. Clear the PSWE bit to redirect MOVX write commands to the XRAM data space. Step 9. Re-enable interrupts. Write/Erase timing is automatically controlled by hardware. Note that code execution in the 8051 is stalled while the Flash is being programmed or erased. Table 16.1. Flash Electrical Characteristics Parameter Conditions Flash Size * C8051F060/1/2/3/4/5 Flash Size * C8051F066/7 Endurance Erase Cycle Time Write Cycle Time * Includes 128-byte Scratch Pad Area Min 20 k 10 40 Typ 65664 † 32896 100 k 12 50 Max 14 60 Units Bytes Bytes Erase/Write ms μs † 1024 Bytes at location 0xFC00 to 0xFFFF are reserved. 16.2. Non-volatile Data Storage The Flash memory can be used for non-volatile data storage as well as program code. This allows data such as calibration coefficients to be calculated and stored at run time. Data is written using the MOVX write instruction (as described in the previous section) and read using the MOVC instruction. An additional 128-byte sector of Flash memory is included for non-volatile data storage. Its smaller sector size makes it particularly well suited as general purpose, non-volatile scratchpad memory. Even though Flash memory can be written a single byte at a time, an entire sector must be erased first. In order to change a single byte of a multi-byte data set, the data must be moved to temporary storage. The 128-byte sector size facilitates updating data without wasting program memory or RAM space. The 128-byte sector is double-mapped over the normal Flash memory area; its address ranges from 0x00 to 0x7F (see Figure 16.1 and Figure 16.2). To access this 128-byte sector, the SFLE bit in PSCTL must be set to logic 1. Code execution from this 128-byte scratchpad sector is not supported. 178 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 16.3. Security Options The CIP-51 provides security options to protect the Flash memory from inadvertent modification by software as well as prevent the viewing of proprietary program code and constants. The Program Store Write Enable (PSCTL.0) and the Program Store Erase Enable (PSCTL.1) bits protect the Flash memory from accidental modification by software. These bits must be explicitly set to logic 1 before software can write or erase the Flash memory. Additional security features prevent proprietary program code and data constants from being read or altered across the JTAG interface or by software running on the system controller. A set of security lock bytes protect the Flash program memory from being read or altered across the JTAG interface. Each bit in a security lock-byte protects one 8k-byte block of memory. Clearing a bit to logic 0 in a Read Lock Byte prevents the corresponding block of Flash memory from being read across the JTAG interface. Clearing a bit in the Write/Erase Lock Byte protects the block from JTAG erasures and/or writes. The Scratchpad area is read or write/erase locked when all bits in the corresponding security byte are cleared to logic 0. On the C8051F060/1/2/3/4/5, the security lock bytes are located at 0xFBFE (Write/Erase Lock) and 0xFBFF (Read Lock), as shown in Figure 16.1. On the C8051F066/7, the security lock bytes are located at 0x7FFE (Write/Erase Lock) and 0x7FFF (Read Lock), as shown in Figure 16.2. The 512-byte sector containing the lock bytes can be written to, but not erased, by software. An attempted read of a read-locked byte returns undefined data. Debugging code in a read-locked sector is not possible through the JTAG interface. The lock bits can always be read from and written to logic 0 regardless of the security setting applied to the block containing the security bytes. This allows additional blocks to be protected after the block containing the security bytes has been locked. Important Note: To ensure protection from external access, the block containing the lock bytes must be Write/Erase locked. On the 64 k byte devices (C8051F060/1/2/3/4/5), the page containing the security bytes is 0xFA00-0xFBFF, and is locked by clearing bit 7 of the Write/Erase Lock Byte. On the 32 k byte devices (C8051F066/7), the page containing the security bytes is 0x7E00-0x7FFF, and is locked by clearing bit 3 of the Write/Erase Lock Byte. If the page containing the security bytes is not Write/Erase locked, it is still possible to erase this page of Flash memory through the JTAG port and reset the security bytes. When the page containing the security bytes has been Write/Erase locked, a JTAG full device erase must be performed to unlock any areas of Flash protected by the security bytes. A JTAG full device erase is initiated by performing a normal JTAG erase operation on either of the security byte locations. This operation must be initiated through the JTAG port, and cannot be performed from firmware running on the device. Rev. 1.3 179 C8051F060/1/2/3/4/5/6/7 Figure 16.1. C8051F060/1/2/3/4/5 Flash Program Memory Map and Security Bytes Flash Read Lock Byte Bits7-0: Each bit locks a corresponding block of memory. (Bit7 is MSB). 0: Read operations are locked (disabled) for corresponding block across the JTAG interface. 1: Read operations are unlocked (enabled) for corresponding block across the JTAG interface. Flash Write/Erase Lock Byte Bits7-0: Each bit locks a corresponding block of memory. 0: Write/Erase operations are locked (disabled) for corresponding block across the JTAG interface. 1: Write/Erase operations are unlocked (enabled) for corresponding block across the JTAG interface. NOTE: When the block containing the security bytes is locked, the security bytes may be written but not erased. Flash Access Limit The Flash Access Limit is defined by the setting of the FLACL register, as described in Figure 16.3. Firmware running at or above this address is prohibited from using the MOVX and MOVC instructions to read, write, or erase Flash locations below this address. 180 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 16.2. C8051F066/7 Flash Program Memory Map and Security Bytes Flash Read Lock Byte Bits7-0: Each bit locks a corresponding block of memory. 0: Read operations are locked (disabled) for corresponding block across the JTAG interface. 1: Read operations are unlocked (enabled) for corresponding block across the JTAG interface. Flash Write/Erase Lock Byte Bits7-0: Each bit locks a corresponding block of memory. 0: Write/Erase operations are locked (disabled) for corresponding block across the JTAG interface. 1: Write/Erase operations are unlocked (enabled) for corresponding block across the JTAG interface. NOTE: When the block containing the security bytes is locked, the security bytes may be written but not erased. Flash Access Limit Register (FLACL) The Flash Access Limit is defined by the setting of the FLACL register, as described in Figure 16.3. Firmware running at or above this address is prohibited from using the MOVX and MOVC instructions to read, write, or erase Flash locations below this address. The Flash Access Limit security feature (see Figure 16.3) protects proprietary program code and data from being read by software running on the C8051F060/1/2/3/4/5/6/7. This feature provides support for OEMs that wish to program the MCU with proprietary value-added firmware before distribution. The value-added firmware can be protected while allowing additional code to be programmed in remaining program memory space later. The Flash Access Limit (FAL) is a 16-bit address that establishes two logical partitions in the program memory space. The first is an upper partition consisting of all the program memory locations at or above the FAL address, and the second is a lower partition consisting of all the program memory locations start- Rev. 1.3 181 C8051F060/1/2/3/4/5/6/7 ing at 0x0000 up to (but excluding) the FAL address. Software in the upper partition can execute code in the lower partition, but is prohibited from reading locations in the lower partition using the MOVC instruction. (Executing a MOVC instruction from the upper partition with a source address in the lower partition will always return a data value of 0x00.) Software running in the lower partition can access locations in both the upper and lower partition without restriction. The Value-added firmware should be placed in the lower partition. On reset, control is passed to the valueadded firmware via the reset vector. Once the value-added firmware completes its initial execution, it branches to a predetermined location in the upper partition. If entry points are published, software running in the upper partition may execute program code in the lower partition, but it cannot read the contents of the lower partition. Parameters may be passed to the program code running in the lower partition either through the typical method of placing them on the stack or in registers before the call or by placing them in prescribed memory locations in the upper partition. The FAL address is specified using the contents of the Flash Access Limit Register. The 16-bit FAL address is calculated as 0xNN00, where NN is the contents of the FAL Security Register. Thus, the FAL can be located on 256-byte boundaries anywhere in program memory space. However, the 512-byte erase sector size essentially requires that a 512 boundary be used. The contents of a non-initialized FAL security byte is 0x00, thereby setting the FAL address to 0x0000 and allowing read access to all locations in program memory space by default. Figure 16.3. FLACL: Flash Access Limit R/W R/W R/W R/W R/W R/W R/W R/W Reset Value 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 SFR Address: SFR Address: 0xB7 SFR Page: F Bit0 Bits 7-0: FLACL: Flash Access Limit. This register holds the high byte of the 16-bit program memory read/write/erase limit address. The entire 16-bit access limit address value is calculated as 0xNN00 where NN is replaced by contents of FLACL. A write to this register sets the Flash Access Limit. This register can only be written once after any reset. Any subsequent writes are ignored until the next reset. To fully protect all addresses below this limit, bit 0 of FLACL should be set to ‘0’ to align the FAL on a 512-byte Flash page boundary. 182 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 16.3.1. Summary of Flash Security Options There are three Flash access methods supported on the C8051F060/1/2/3/4/5/6/7; 1) Accessing Flash through the JTAG debug interface, 2) Accessing Flash from firmware residing below the Flash Access Limit, and 3) Accessing Flash from firmware residing at or above the Flash Access Limit. Accessing Flash through the JTAG debug interface: 1. The Read and Write/Erase Lock bytes (security bytes) provide security for Flash access through the JTAG interface. 2. Any unlocked page may be read from, written to, or erased. 3. Locked pages cannot be read from, written to, or erased. 4. Reading the security bytes is always permitted. 5. Locking additional pages by writing to the security bytes is always permitted. 6. If the page containing the security bytes is unlocked, it can be directly erased. Doing so will reset the security bytes and unlock all pages of Flash. 7. If the page containing the security bytes is locked, it cannot be directly erased. To unlock the page containing the security bytes, a full JTAG device erase is required. A full JTAG device erase will erase all Flash pages, including the page containing the security bytes and the security bytes themselves. 8. The Reserved Area cannot be read from, written to, or erased at any time. Accessing Flash from firmware residing below the Flash Access Limit: 1. The Read and Write/Erase Lock bytes (security bytes) do not restrict Flash access from user firmware. 2. Any page of Flash except the page containing the security bytes may be read from, written to, or erased. 3. The page containing the security bytes cannot be erased. Unlocking pages of Flash can only be performed via the JTAG interface. 4. The page containing the security bytes may be read from or written to. Pages of Flash can be locked from JTAG access by writing to the security bytes. 5. The Reserved Area cannot be read from, written to, or erased at any time. Accessing Flash from firmware residing at or above the Flash Access Limit: 1. The Read and Write/Erase Lock bytes (security bytes) do not restrict Flash access from user firmware. 2. Any page of Flash at or above the Flash Access Limit except the page containing the security bytes may be read from, written to, or erased. 3. Any page of Flash below the Flash Access Limit cannot be read from, written to, or erased. 4. Code branches to locations below the Flash Access Limit are permitted. 5. The page containing the security bytes cannot be erased. Unlocking pages of Flash can only be performed via the JTAG interface. 6. The page containing the security bytes may be read from or written to. Pages of Flash can be locked from JTAG access by writing to the security bytes. 7. The Reserved Area cannot be read from, written to, or erased at any time. Rev. 1.3 183 C8051F060/1/2/3/4/5/6/7 Figure 16.4. FLSCL: Flash Memory Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value FOSE FRAE Reserved Reserved Reserved Reserved Reserved FLWE 10000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit 7: FOSE: Flash One-Shot Timer Enable This is the timer that turns off the sense amps after a Flash read. 0: Flash One-Shot Timer disabled. 1: Flash One-Shot Timer enabled (recommended setting.) Bit 6: FRAE: Flash Read Always Enable 0: Flash reads occur as necessary (recommended setting.). 1: Flash reads occur every system clock cycle. Bits 5-1: RESERVED. Read = 00000b. Must Write 00000b. Bit 0: FLWE: Flash Write/Erase Enable This bit must be set to allow Flash writes/erases from user software. 0: Flash writes/erases disabled. 1: Flash writes/erases enabled. 184 Rev. 1.3 SFR Address: SFR Address: 0xB7 SFR Page: 0 Bit0 C8051F060/1/2/3/4/5/6/7 Figure 16.5. PSCTL: Program Store Read/Write Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - - - - SFLE PSEE PSWE 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 SFR Address: SFR Address: 0x8F SFR Page: 0 Bit0 Bits 7-3: UNUSED. Read = 00000b, Write = don't care. Bit 2: SFLE: Scratchpad Flash Memory Access Enable When this bit is set, Flash MOVC reads and writes from user software are directed to the 128-byte Scratchpad Flash sector. When SFLE is set to logic 1, Flash accesses out of the address range 0x00-0x7F should not be attempted. Reads/Writes out of this range will yield undefined results. 0: Flash access from user software directed to the Program/Data Flash sector. 1: Flash access from user software directed to the Scratchpad sector. Bit 1: PSEE: Program Store Erase Enable. Setting this bit allows an entire page of the Flash program memory to be erased provided the PSWE bit is also set. After setting this bit, a write to Flash memory using the MOVX instruction will erase the entire page that contains the location addressed by the MOVX instruction. The value of the data byte written does not matter. Note: The Flash page containing the Read Lock Byte and Write/Erase Lock Byte cannot be erased by software. 0: Flash program memory erasure disabled. 1: Flash program memory erasure enabled. Bit 0: PSWE: Program Store Write Enable. Setting this bit allows writing a byte of data to the Flash program memory using the MOVX write instruction. The location must be erased prior to writing data. 0: Write to Flash program memory disabled. MOVX write operations target External RAM. 1: Write to Flash program memory enabled. MOVX write operations target Flash memory. Rev. 1.3 185 C8051F060/1/2/3/4/5/6/7 186 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 17. External Data Memory Interface and On-Chip XRAM The C8051F060/1/2/3/4/5/6/7 MCUs include 4 k bytes of on-chip RAM mapped into the external data memory space (XRAM). In addition, the C8051F060/2/4/6 include an External Data Memory Interface which can be used to access off-chip memories and memory-mapped devices connected to the GPIO ports. The external memory space may be accessed using the external move instruction (MOVX) and the data pointer (DPTR), or using the MOVX indirect addressing mode using R0 or R1. If the MOVX instruction is used with an 8-bit address operand (such as @R1), then the high byte of the 16-bit address is provided by the External Memory Interface Control Register (EMI0CN, shown in Figure 17.1). Note: the MOVX instruction can also be used for writing to the Flash memory. See Section “16. Flash Memory” on page 177 for details. The MOVX instruction accesses XRAM by default. 17.1. Accessing XRAM The XRAM memory space (both internal and external) is accessed using the MOVX instruction. The MOVX instruction has two forms, both of which use an indirect addressing method. The first method uses the Data Pointer, DPTR, a 16-bit register which contains the effective address of the XRAM location to be read or written. The second method uses R0 or R1 in combination with the EMI0CN register to generate the effective XRAM address. Examples of both of these methods are given below. 17.1.1. 16-Bit MOVX Example The 16-bit form of the MOVX instruction accesses the memory location pointed to by the contents of the DPTR register. The following series of instructions reads the value of the byte at address 0x1234 into the accumulator A: MOV MOVX DPTR, #1234h A, @DPTR ; load DPTR with 16-bit address to read (0x1234) ; load contents of 0x1234 into accumulator A The above example uses the 16-bit immediate MOV instruction to set the contents of DPTR. Alternately, the DPTR can be accessed through the SFR registers DPH, which contains the upper 8-bits of DPTR, and DPL, which contains the lower 8-bits of DPTR. 17.1.2. 8-Bit MOVX Example The 8-bit form of the MOVX instruction uses the contents of the EMI0CN SFR to determine the upper 8-bits of the effective address to be accessed and the contents of R0 or R1 to determine the lower 8-bits of the effective address to be accessed. The following series of instructions read the contents of the byte at address 0x1234 into the accumulator A. MOV MOV MOVX EMI0CN, #12h R0, #34h a, @R0 ; load high byte of address into EMI0CN ; load low byte of address into R0 (or R1) ; load contents of 0x1234 into accumulator A Rev. 1.3 187 C8051F060/1/2/3/4/5/6/7 17.2. Configuring the External Memory Interface Configuring the External Memory Interface consists of four steps: 1. Enable the EMIF on the High Ports (P7, P6, P5, and P4). 2. Configure the Output Modes of the port pins as either push-pull or open-drain (push-pull is most common). 3. Configure Port latches to “park” the EMIF pins in a dormant state (usually by setting them to logic ‘1’). 4. Select Multiplexed mode or Non-multiplexed mode. 5. Select the memory mode (on-chip only, split mode without bank select, split mode with bank select, or off-chip only). 6. Set up timing to interface with off-chip memory or peripherals. Each of these four steps is explained in detail in the following sections. The Port enable bit, Multiplexed mode selection, and Mode bits are located in the EMI0CF register shown in Figure 17.2. 17.3. Port Selection and Configuration When enabled, the External Memory Interface appears on Ports 7, 6, 5, and 4 in non-multiplexed mode, or Ports 7, 6, and 4 in multiplexed mode. The External Memory Interface claims the associated Port pins for memory operations ONLY during the execution of an off-chip MOVX instruction. Once the MOVX instruction has completed, control of the Port pins reverts to the Port latches. See Section “18. Port Input/Output” on page 203 for more information about the Port operation and configuration. The Port latches should be explicitly configured to ‘park’ the External Memory Interface pins in a dormant state when not in use, most commonly by setting them to a logic 1. During the execution of the MOVX instruction, the External Memory Interface will explicitly disable the drivers on all Port pins that are acting as Inputs (Data[7:0] during a READ operation, for example). The Output mode of the Port pins (whether the pin is configured as Open-Drain or Push-Pull) is unaffected by the External Memory Interface operation, and remains controlled by the PnMDOUT registers. See Section “18. Port Input/Output” on page 203 for more information about Port output mode configuration. 188 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 17.1. EMI0CN: External Memory Interface Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value PGSEL7 PGSEL6 PGSEL5 PGSEL4 PGSEL3 PGSEL2 PGSEL1 PGSEL0 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-0: Bit0 SFR Address: 0xA2 SFR Page: 0 PGSEL[7:0]: XRAM Page Select Bits. The XRAM Page Select Bits provide the high byte of the 16-bit external data memory address when using an 8-bit MOVX command, effectively selecting a 256-byte page of RAM. 0x00: 0x0000 to 0x00FF 0x01: 0x0100 to 0x01FF ... 0xFE: 0xFE00 to 0xFEFF 0xFF: 0xFF00 to 0xFFFF Figure 17.2. EMI0CF: External Memory Configuration R/W R/W R/W R/W R/W R/W R/W R/W Reset Value - - PRTSEL EMD2 EMD1 EMD0 EALE1 EALE0 00000011 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-6: Bit5: Bit4: Bits3-2: Bits1-0: Bit0 SFR Address: 0xA3 SFR Page: 0 Unused. Read = 00b. Write = don’t care. PRTSEL: EMIF Port Select. 0: EMIF not mapped to port pins. 1: EMIF active on P4-P7. EMD2: EMIF Multiplex Mode Select. 0: EMIF operates in multiplexed address/data mode. 1: EMIF operates in non-multiplexed mode (separate address and data pins). EMD1-0: EMIF Operating Mode Select. These bits control the operating mode of the External Memory Interface. 00: Internal Only: MOVX accesses on-chip XRAM only. All effective addresses alias to on-chip memory space. 01: Split Mode without Bank Select: Accesses below the 4 kB boundary are directed on-chip. Accesses above the 4 kB boundary are directed off-chip. 8-bit off-chip MOVX operations use the current contents of the Address High port latches to resolve upper address byte. Note that in order to access off-chip space, EMI0CN must be set to a page that is not contained in the on-chip address space. 10: Split Mode with Bank Select: Accesses below the 4 kB boundary are directed on-chip. Accesses above the 4 kB boundary are directed off-chip. 8-bit off-chip MOVX operations use the contents of EMI0CN to determine the high-byte of the address. 11: External Only: MOVX accesses off-chip XRAM only. On-chip XRAM is not visible to the CPU. EALE1-0: ALE Pulse-Width Select Bits (only has effect when EMD2 = 0). 00: ALE high and ALE low pulse width = 1 SYSCLK cycle. 01: ALE high and ALE low pulse width = 2 SYSCLK cycles. 10: ALE high and ALE low pulse width = 3 SYSCLK cycles. 11: ALE high and ALE low pulse width = 4 SYSCLK cycles. Rev. 1.3 189 C8051F060/1/2/3/4/5/6/7 17.4. Multiplexed and Non-multiplexed Selection The External Memory Interface is capable of acting in a Multiplexed mode or a Non-multiplexed mode, depending on the state of the EMD2 (EMI0CF.4) bit. 17.4.1. Multiplexed Configuration In Multiplexed mode, the Data Bus and the lower 8-bits of the Address Bus share the same Port pins: AD[7:0]. In this mode, an external latch (74HC373 or equivalent logic gate) is used to hold the lower 8-bits of the RAM address. The external latch is controlled by the ALE (Address Latch Enable) signal, which is driven by the External Memory Interface logic. An example of a Multiplexed Configuration is shown in Figure 17.3. In Multiplexed mode, the external MOVX operation can be broken into two phases delineated by the state of the ALE signal. During the first phase, ALE is high and the lower 8-bits of the Address Bus are presented to AD[7:0]. During this phase, the address latch is configured such that the ‘Q’ outputs reflect the states of the ‘D’ inputs. When ALE falls, signaling the beginning of the second phase, the address latch outputs remain fixed and are no longer dependent on the latch inputs. Later in the second phase, the Data Bus controls the state of the AD[7:0] port at the time /RD or /WR is asserted. See Section “17.6.2. Multiplexed Mode” on page 199 for more information. Figure 17.3. Multiplexed Configuration Example 190 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 17.4.2. Non-multiplexed Configuration In Non-multiplexed mode, the Data Bus and the Address Bus pins are not shared. An example of a Nonmultiplexed Configuration is shown in Figure 17.4. See Section “17.6.1. Non-multiplexed Mode” on page 196 for more information about Non-multiplexed operation. Figure 17.4. Non-multiplexed Configuration Example Rev. 1.3 191 C8051F060/1/2/3/4/5/6/7 17.5. Memory Mode Selection The external data memory space can be configured in one of four modes, shown in Figure 17.5, based on the EMIF Mode bits in the EMI0CF register (Figure 17.2). These modes are summarized below. More information about the different modes can be found in Section “17.6. Timing” on page 194. 17.5.1. Internal XRAM Only When EMI0CF.[3:2] are set to ‘00’, all MOVX instructions will target the internal XRAM space on the device. Memory accesses to addresses beyond the populated space will wrap on 4 k byte boundaries. As an example, the addresses 0x1000 and 0x2000 both evaluate to address 0x0000 in on-chip XRAM space. • • 8-bit MOVX operations use the contents of EMI0CN to determine the high-byte of the effective address and R0 or R1 to determine the low-byte of the effective address. 16-bit MOVX operations use the contents of the 16-bit DPTR to determine the effective address. 17.5.2. Split Mode without Bank Select When EMI0CF.[3:2] are set to ‘01’, the XRAM memory map is split into two areas, on-chip space and offchip space. • • • • Effective addresses below the 4 kB boundary will access on-chip XRAM space. Effective addresses beyond the 4 kB boundary will access off-chip space. 8-bit MOVX operations use the contents of EMI0CN to determine whether the memory access is onchip or off-chip. However, in the “No Bank Select” mode, an 8-bit MOVX operation will not drive the upper 8-bits A[15:8] of the Address Bus during an off-chip access. This allows the user to manipulate the upper address bits at will by setting the Port state directly. This behavior is in contrast with “Split Mode with Bank Select” described below. The lower 8-bits of the Address Bus A[7:0] are driven, determined by R0 or R1. 16-bit MOVX operations use the contents of DPTR to determine whether the memory access is onchip or off-chip, and unlike 8-bit MOVX operations, the full 16-bits of the Address Bus A[15:0] are driven during the off-chip transaction. Figure 17.5. EMIF Operating Modes 192 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 17.5.3. Split Mode with Bank Select When EMI0CF.[3:2] are set to ‘10’, the XRAM memory map is split into two areas, on-chip space and offchip space. • • • • Effective addresses below the 4 kB boundary will access on-chip XRAM space. Effective addresses beyond the 4 kB boundary will access off-chip space. 8-bit MOVX operations use the contents of EMI0CN to determine whether the memory access is onchip or off-chip. The upper 8-bits of the Address Bus A[15:8] are determined by EMI0CN, and the lower 8-bits of the Address Bus A[7:0] are determined by R0 or R1. All 16-bits of the Address Bus A[15:0] are driven in “Bank Select” mode. 16-bit MOVX operations use the contents of DPTR to determine whether the memory access is onchip or off-chip, and the full 16-bits of the Address Bus A[15:0] are driven during the off-chip transaction. 17.5.4. External Only When EMI0CF[3:2] are set to ‘11’, all MOVX operations are directed to off-chip space. On-chip XRAM is not visible to the CPU. This mode is useful for accessing off-chip memory located between 0x0000 and the 4 kB boundary. • • 8-bit MOVX operations ignore the contents of EMI0CN. The upper Address bits A[15:8] are not driven (identical behavior to an off-chip access in “Split Mode without Bank Select” described above). This allows the user to manipulate the upper address bits at will by setting the Port state directly. The lower 8-bits of the effective address A[7:0] are determined by the contents of R0 or R1. 16-bit MOVX operations use the contents of DPTR to determine the effective address A[15:0]. The full 16-bits of the Address Bus A[15:0] are driven during the off-chip transaction. Rev. 1.3 193 C8051F060/1/2/3/4/5/6/7 17.6. Timing The timing parameters of the External Memory Interface can be configured to enable connection to devices having different setup and hold time requirements. The Address Setup time, Address Hold time, / RD and /WR strobe widths, and in multiplexed mode, the width of the ALE pulse are all programmable in units of SYSCLK periods through EMI0TC, shown in Figure 17.6, and EMI0CF[1:0]. The timing for an off-chip MOVX instruction can be calculated by adding 4 SYSCLK cycles to the timing parameters defined by the EMI0TC register. Assuming non-multiplexed operation, the minimum execution time for an off-chip XRAM operation is 5 SYSCLK cycles (1 SYSCLK for /RD or /WR pulse + 4 SYSCLKs). For multiplexed operations, the Address Latch Enable signal will require a minimum of 2 additional SYSCLK cycles. Therefore, the minimum execution time for an off-chip XRAM operation in multiplexed mode is 7 SYSCLK cycles (2 for /ALE + 1 for /RD or /WR + 4). The programmable setup and hold times default to the maximum delay settings after a reset. Figure 17.6. EMI0TC: External Memory Timing Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value EAS1 EAS0 ERW3 EWR2 EWR1 EWR0 EAH1 EAH0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-6: Bits5-2: Bits1-0: 194 EAS1-0: EMIF Address Setup Time Bits. 00: Address setup time = 0 SYSCLK cycles. 01: Address setup time = 1 SYSCLK cycle. 10: Address setup time = 2 SYSCLK cycles. 11: Address setup time = 3 SYSCLK cycles. EWR3-0: EMIF /WR and /RD Pulse-Width Control Bits. 0000: /WR and /RD pulse width = 1 SYSCLK cycle. 0001: /WR and /RD pulse width = 2 SYSCLK cycles. 0010: /WR and /RD pulse width = 3 SYSCLK cycles. 0011: /WR and /RD pulse width = 4 SYSCLK cycles. 0100: /WR and /RD pulse width = 5 SYSCLK cycles. 0101: /WR and /RD pulse width = 6 SYSCLK cycles. 0110: /WR and /RD pulse width = 7 SYSCLK cycles. 0111: /WR and /RD pulse width = 8 SYSCLK cycles. 1000: /WR and /RD pulse width = 9 SYSCLK cycles. 1001: /WR and /RD pulse width = 10 SYSCLK cycles. 1010: /WR and /RD pulse width = 11 SYSCLK cycles. 1011: /WR and /RD pulse width = 12 SYSCLK cycles. 1100: /WR and /RD pulse width = 13 SYSCLK cycles. 1101: /WR and /RD pulse width = 14 SYSCLK cycles. 1110: /WR and /RD pulse width = 15 SYSCLK cycles. 1111: /WR and /RD pulse width = 16 SYSCLK cycles. EAH1-0: EMIF Address Hold Time Bits. 00: Address hold time = 0 SYSCLK cycles. 01: Address hold time = 1 SYSCLK cycle. 10: Address hold time = 2 SYSCLK cycles. 11: Address hold time = 3 SYSCLK cycles. Rev. 1.3 Bit0 SFR Address: 0xA1 SFR Page: 0 C8051F060/1/2/3/4/5/6/7 Table 17.1 lists the AC parameters for the External Memory Interface, and Figure 17.7 through Figure 17.12 show the timing diagrams for the different External Memory Interface modes and MOVX operations. Rev. 1.3 195 C8051F060/1/2/3/4/5/6/7 17.6.1. Non-multiplexed Mode 17.6.1.1.16-bit MOVX: EMI0CF[4:2] = ‘101’, ‘110’, or ‘111’. Figure 17.7. Non-multiplexed 16-bit MOVX Timing 196 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 17.6.1.2.8-bit MOVX without Bank Select: EMI0CF[4:2] = ‘101’ or ‘111’. Figure 17.8. Non-multiplexed 8-bit MOVX without Bank Select Timing Rev. 1.3 197 C8051F060/1/2/3/4/5/6/7 17.6.1.3.8-bit MOVX with Bank Select: EMI0CF[4:2] = ‘110’. Figure 17.9. Non-multiplexed 8-bit MOVX with Bank Select Timing 198 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 17.6.2. Multiplexed Mode 17.6.2.1.16-bit MOVX: EMI0CF[4:2] = ‘001’, ‘010’, or ‘011’. Figure 17.10. Multiplexed 16-bit MOVX Timing Rev. 1.3 199 C8051F060/1/2/3/4/5/6/7 17.6.2.2.8-bit MOVX without Bank Select: EMI0CF[4:2] = ‘001’ or ‘011’. Figure 17.11. Multiplexed 8-bit MOVX without Bank Select Timing 200 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 17.6.2.3.8-bit MOVX with Bank Select: EMI0CF[4:2] = ‘010’. Figure 17.12. Multiplexed 8-bit MOVX with Bank Select Timing Rev. 1.3 201 C8051F060/1/2/3/4/5/6/7 Table 17.1. AC Parameters for External Memory Interface Parameter Description TSYSCLK System Clock Period 40 TACS Address / Control Setup Time 0 3*TSYSCLK ns TACW Address / Control Pulse Width 1*TSYSCLK 16*TSYSCLK ns TACH Address / Control Hold Time 0 3*TSYSCLK ns TALEH Address Latch Enable High Time 1*TSYSCLK 4*TSYSCLK ns TALEL Address Latch Enable Low Time 1*TSYSCLK 4*TSYSCLK ns TWDS Write Data Setup Time 1*TSYSCLK 19*TSYSCLK ns TWDH Write Data Hold Time 0 3*TSYSCLK ns TRDS Read Data Setup Time 20 ns TRDH Read Data Hold Time 0 ns 202 Min Rev. 1.3 Max Units ns C8051F060/1/2/3/4/5/6/7 18. Port Input/Output The C8051F06x family of devices are fully integrated mixed-signal System on a Chip MCUs with 59 digital I/O pins (C8051F060/2/4/6) or 24 digital I/O pins (C8051F061/3/5/7), organized as 8-bit Ports. All ports are both bit- and byte-addressable through their corresponding Port Data registers. All Port pins support configurable Open-Drain or Push-Pull output modes and weak pull-ups. Additionally, Port 0 pins are 5 V-tolerant. A block diagram of the Port I/O cell is shown in Figure 18.1. Complete Electrical Specifications for the Port I/O pins are given in Table 18.1. Figure 18.1. Port I/O Cell Block Diagram Table 18.1. Port I/O DC Electrical Characteristics VDD = 2.7 to 3.6 V, -40 to +85 °C unless otherwise specified. Parameter Conditions Min Output High Voltage (VOH) IOH = -3 mA, Port I/O Push-Pull IOH = -10 μA, Port I/O Push-Pull Output Low Voltage (VOL) IOL = 8.5 mA IOL = 10 μA Typ VDD - 0.7 VDD - 0.1 Units V 0.6 0.1 Input High Voltage (VIH) V 0.7 x VDD Input Low Voltage (VIL) Input Leakage Current Max 0.3 x VDD DGND < Port Pin < VDD, Pin Tri-state Weak Pull-up Off Weak Pull-up On Input Capacitance Rev. 1.3 10 ±1 μA μA 5 pF 203 C8051F060/1/2/3/4/5/6/7 The C8051F06x family of devices have a wide array of digital resources which are available through the four lower I/O Ports: P0, P1, P2, and (on the C8051F060/2/4/6) P3. Each of the pins on P0, P1, P2, and P3, can be defined as a General-Purpose I/O (GPIO) pin or can be controlled by a digital peripheral or function (like UART0 or /INT1 for example), as shown in Figure 18.2. The system designer controls which digital functions are assigned pins, limited only by the number of pins available. This resource assignment flexibility is achieved through the use of a Priority Crossbar Decoder. Note that the state of a Port I/O pin can always be read from its associated Data register regardless of whether that pin has been assigned to a digital peripheral or behaves as GPIO. The Port pins on Port 2 can be used as analog inputs to the analog Voltage comparators. On the C8051F060/1/2/3, the pins of Port 1 can be used as analog inputs for ADC2. The upper Ports (available on C8051F060/2/4/6) can be byte-accessed as GPIO pins, or used as part of an External Memory Interface which is active during a MOVX instruction whose target address resides in off-chip memory. See Section “17. External Data Memory Interface and On-Chip XRAM” on page 187 for more information about the External Memory Interface. Figure 18.2. Port I/O Functional Block Diagram 204 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 18.1. Ports 0 through 3 and the Priority Crossbar Decoder The Priority Crossbar Decoder, or “Crossbar”, allocates and assigns Port pins on Port 0 through Port 3 to the digital peripherals (UARTs, SMBus, PCA, Timers, etc.) on the device using a priority order. The Port pins are allocated in order starting with P0.0 and continue through P3.7 (on the C8051F060/2/4/6) or P2.7 (on the C8051F061/3/5/7) if necessary. The digital peripherals are assigned Port pins in a priority order which is listed in Figure 18.3, with UART0 having the highest priority and CNVSTR2 having the lowest priority. 18.1.1. Crossbar Pin Assignment and Allocation The Crossbar assigns Port pins to a peripheral if the corresponding enable bits of the peripheral are set to a logic 1 in the Crossbar configuration registers XBR0, XBR1, XBR2, and XBR3, shown in Figure 18.5, Figure 18.6, Figure 18.7, and Figure 18.8. For example, if the UART0EN bit (XBR0.2) is set to a logic 1, the TX0 and RX0 pins will be mapped to P0.0 and P0.1 respectively. Because UART0 has the highest priority, its pins will always be mapped to P0.0 and P0.1 when UART0EN is set to a logic 1. If a digital periphFigure 18.3. Priority Crossbar Decode Table (P1MDIN = 0xFF; P2MDIN = 0xFF) Rev. 1.3 205 C8051F060/1/2/3/4/5/6/7 eral’s enable bits are not set to a logic 1, then its ports are not accessible at the Port pins of the device. Also note that the Crossbar assigns pins to all associated functions when the SMBus, UART0 or UART1 are selected (i.e. SMBus, SPI, UART). It would be impossible, for example, to assign TX0 to a Port pin without assigning RX0 as well. The SPI can operate in 3 or 4-wire mode (with or without NSS). Each combination of enabled peripherals results in a unique device pinout. All Port pins on Ports 0 through 3 that are not allocated by the Crossbar can be accessed as General-Purpose I/O (GPIO) pins by reading and writing the associated Port Data registers (See Figure 18.9, Figure 18.11, Figure 18.14, and Figure 18.17), a set of SFRs which are both byte- and bit-addressable. The output states of Port pins that are allocated by the Crossbar are controlled by the digital peripheral that is mapped to those pins. Writes to the Port Data registers (or associated Port bits) will have no effect on the states of these pins. A Read of a Port Data register (or Port bit) will always return the logic state present at the pin itself, regardless of whether the Crossbar has allocated the pin for peripheral use or not. An exception to this occurs during the execution of a read-modify-write instruction (ANL, ORL, XRL, CPL, INC, DEC, DJNZ, JBC, CLR, SETB, and the bitwise MOV write operation). During the read cycle of the read-modify-write instruction, it is the contents of the Port Data register, not the state of the Port pins themselves, which is read. Because the Crossbar registers affect the pinout of the peripherals of the device, they are typically configured in the initialization code of the system before the peripherals themselves are configured. Once configured, the Crossbar registers are typically left alone. Once the Crossbar registers have been properly configured, the Crossbar is enabled by setting XBARE (XBR2.4) to a logic 1. Until XBARE is set to a logic 1, the output drivers on Ports 0 through 3 are explicitly disabled in order to prevent possible contention on the Port pins while the Crossbar registers and other registers which can affect the device pinout are being written. The output drivers on Crossbar-assigned input signals (like RX0, for example) are explicitly disabled; thus the values of the Port Data registers and the PnMDOUT registers have no effect on the states of these pins. 18.1.2. Configuring the Output Modes of the Port Pins The output drivers on Ports 0 through 3 remain disabled until the Crossbar is enabled by setting XBARE (XBR2.4) to a logic 1. The output mode of each port pin can be configured to be either Open-Drain or Push-Pull. In the Push-Pull configuration, writing a logic 0 to the associated bit in the Port Data register will cause the Port pin to be driven to GND, and writing a logic 1 will cause the Port pin to be driven to VDD. In the Open-Drain configuration, writing a logic 0 to the associated bit in the Port Data register will cause the Port pin to be driven to GND, and a logic 1 will cause the Port pin to assume a high-impedance state. The Open-Drain configuration is useful to prevent contention between devices in systems where the Port pin participates in a shared interconnection in which multiple outputs are connected to the same physical wire (like the SDA signal on an SMBus connection). The output modes of the Port pins on Ports 0 through 3 are determined by the bits in the associated PnMDOUT registers (See Figure 18.10, Figure 18.13, Figure 18.16, and Figure 18.18). For example, a logic 1 in P3MDOUT.7 will configure the output mode of P3.7 to Push-Pull; a logic 0 in P3MDOUT.7 will configure the output mode of P3.7 to Open-Drain. All Port pins default to Open-Drain output. 206 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 The PnMDOUT registers control the output modes of the port pins regardless of whether the Crossbar has allocated the Port pin for a digital peripheral or not. The exceptions to this rule are: the Port pins connected to SDA, SCL, RX0 (if UART0 is in Mode 0), and RX1 (if UART1 is in Mode 0) are always configured as Open-Drain outputs, regardless of the settings of the associated bits in the PnMDOUT registers. 18.1.3. Configuring Port Pins as Digital Inputs A Port pin is configured as a digital input by setting its output mode to “Open-Drain” and writing a logic 1 to the associated bit in the Port Data register. For example, P3.7 is configured as a digital input by setting P3MDOUT.7 to a logic 0 and P3.7 to a logic 1. If the Port pin has been assigned to a digital peripheral by the Crossbar and that pin functions as an input (for example RX0, the UART0 receive pin), then the output drivers on that pin are automatically disabled. 18.1.4. Weak Pull-ups By default, each Port pin has an internal weak pull-up device enabled which provides a resistive connection (about 100 k) between the pin and VDD. The weak pull-up devices can be globally disabled by writing a logic 1 to the Weak Pull-up Disable bit, (WEAKPUD, XBR2.7). The weak pull-up is automatically deactivated on any pin that is driving a logic 0; that is, an output pin will not contend with its own pull-up device. The weak pull-up device can also be explicitly disabled on a Port 1 pin by configuring the pin as an Analog Input, as described below. 18.1.5. Configuring Port 1 and 2 pins as Analog Inputs The pins on Port 1 can serve as analog inputs to the ADC2 analog MUX (C8051F060/1/2/3 only) and the pins on Port 2 can serve as analog inputs to the Comparators (all devices). A Port pin is configured as an Analog Input by writing a logic 0 to the associated bit in the PnMDIN registers. All Port pins default to a Digital Input mode. Configuring a Port pin as an analog input: 1. Disables the digital input path from the pin. This prevents additional power supply current from being drawn when the voltage at the pin is near VDD / 2. A read of the Port Data bit will return a logic 0 regardless of the voltage at the Port pin. 2. Disables the weak pull-up device on the pin. 3. Causes the Crossbar to “skip over” the pin when allocating Port pins for digital peripherals. Note that the output drivers on a pin configured as an Analog Input are not explicitly disabled. Therefore, the associated PnMDOUT bits of pins configured as Analog Inputs should explicitly be set to logic 0 (Open-Drain output mode), and the associated Port Data bits should be set to logic 1 (high-impedance). Also note that it is not required to configure a Port pin as an Analog Input in order to use it as an input to ADC2 or the Comparators, however, it is strongly recommended. See the analog peripheral’s corresponding section in this datasheet for further information. Rev. 1.3 207 C8051F060/1/2/3/4/5/6/7 18.1.6. Crossbar Pin Assignment Example In this example (Figure 18.4), we configure the Crossbar to allocate Port pins for UART0, the SMBus, all 6 PCA modules, /INT0, and /INT1 (12 pins total). Additionally, we configure P1.2, P1.3, and P1.4 for Analog Input mode so that the voltages at these pins can be measured by ADC2. The configuration steps are as follows: XBR0, XBR1, and XBR2 are set such that UART0EN = 1, SMB0EN = 1, PCA0ME = ‘110’, INT0E = 1, and INT1E = 1. Thus: XBR0 = 0x3D, XBR1 = 0x14, and XBR2 = 0x40. 1. We configure the desired Port 1 pins to Analog Input mode by setting P1MDIN to 0xE3 (P1.4, P1.3, and P1.2 are Analog Inputs, so their associated P1MDIN bits are set to logic 0). 2. We enable the Crossbar by setting XBARE = 1: XBR2 = 0x40. - UART0 has the highest priority, so P0.0 is assigned to TX0, and P0.1 is assigned to RX0. - The SMBus is next in priority order, so P0.2 is assigned to SDA, and P0.3 is assigned to SCL. - PCA0 is next in priority order, so P0.4 through P1.1 are assigned to CEX0 through CEX5 - P1MDIN is set to 0xE3, which configures P1.2, P1.3, and P1.4 as Analog Inputs, causing the Crossbar to skip these pins. - /INT0 is next in priority order, so it is assigned to the next non-skipped pin, which is P1.5. - /INT1 is next in priority order, so it is assigned to P1.6. 3. We set the UART0 TX pin (TX0, P0.0) output and the CEX0-3 outputs to Push-Pull by setting P0MDOUT = 0xF1. 4. We explicitly disable the output drivers on the 3 Analog Input pins by setting the corresponding bits in the P1MDOUT register to ‘0’, and in P1 to ‘1’. Additionally, the CEX5-4 output pins are set to Push-Pull mode. Therefore, P1MDOUT = 0x03 (configure unused pins to Open-Drain) and P1 = 0xFF (a logic 1 selects the high-impedance state). 208 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 18.4. Crossbar Example: (P1MDIN = 0xE3; XBR0 = 0x3D; XBR1 = 0x14; XBR2 = 0x40) Rev. 1.3 209 C8051F060/1/2/3/4/5/6/7 Figure 18.5. XBR0: Port I/O Crossbar Register 0 R/W R/W CP0E ECI0E Bit7 Bit6 Bit7: Bit6: Bits5-3: Bit2: Bit1: Bit0: 210 R/W R/W R/W PCA0ME Bit5 Bit4 Bit3 R/W R/W R/W Reset Value UART0EN SPI0EN SMB0EN 00000000 Bit2 Bit1 Bit0 SFR Address: 0xE1 SFR Page: F CP0E: Comparator 0 Output Enable Bit. 0: CP0 unavailable at Port pin. 1: CP0 routed to Port pin. ECI0E: PCA0 External Counter Input Enable Bit. 0: PCA0 External Counter Input unavailable at Port pin. 1: PCA0 External Counter Input (ECI0) routed to Port pin. PCA0ME: PCA0 Module I/O Enable Bits. 000: All PCA0 I/O unavailable at port pins. 001: CEX0 routed to port pin. 010: CEX0, CEX1 routed to 2 port pins. 011: CEX0, CEX1, and CEX2 routed to 3 port pins. 100: CEX0, CEX1, CEX2, and CEX3 routed to 4 port pins. 101: CEX0, CEX1, CEX2, CEX3, and CEX4 routed to 5 port pins. 110: CEX0, CEX1, CEX2, CEX3, CEX4, and CEX5 routed to 6 port pins. UART0EN: UART0 I/O Enable Bit. 0: UART0 I/O unavailable at Port pins. 1: UART0 TX routed to P0.0, and RX routed to P0.1. SPI0EN: SPI0 Bus I/O Enable Bit. 0: SPI0 I/O unavailable at Port pins. 4-wire mode: 1: SPI0 SCK, MISO, MOSI, and NSS routed to 4 Port pins. 3-wire mode: 1: SPI0 SCK, MISO and MOSI routed to 3 Port pins. SMB0EN: SMBus0 Bus I/O Enable Bit. 0: SMBus0 I/O unavailable at Port pins. 1: SMBus0 SDA and SCL routed to 2 Port pins. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 18.6. XBR1: Port I/O Crossbar Register 1 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value SYSCKE T2EXE T2E INT1E T1E INT0E T0E CP1E 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Bit0 SFR Address: 0xE2 SFR Page: F SYSCKE: /SYSCLK Output Enable Bit. 0: /SYSCLK unavailable at Port pin. 1: /SYSCLK routed to Port pin. T2EXE: T2EX Input Enable Bit. 0: T2EX unavailable at Port pin. 1: T2EX routed to Port pin. T2E: T2 Input Enable Bit. 0: T2 unavailable at Port pin. 1: T2 routed to Port pin. INT1E: /INT1 Input Enable Bit. 0: /INT1 unavailable at Port pin. 1: /INT1 routed to Port pin. T1E: T1 Input Enable Bit. 0: T1 unavailable at Port pin. 1: T1 routed to Port pin. INT0E: /INT0 Input Enable Bit. 0: /INT0 unavailable at Port pin. 1: /INT1 routed to Port pin. T0E: T0 Input Enable Bit. 0: T0 unavailable at Port pin. 1: T1 routed to Port pin. CP1E: CP1 Output Enable Bit. 0: CP1 unavailable at Port pin. 1: CP1 routed to Port pin. Rev. 1.3 211 C8051F060/1/2/3/4/5/6/7 Figure 18.7. XBR2: Port I/O Crossbar Register 2 R/W R/W WEAKPUD Bit7 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bits1-0: 212 R/W R/W R/W R/W R/W XBARE - T4EXE T4E UART1E - Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value - 00000000 Bit0 SFR Address: 0xE3 SFR Page: F WEAKPUD: Weak Pull-Up Disable Bit. 0: Weak pull-ups globally enabled. 1: Weak pull-ups globally disabled. XBARE: Crossbar Enable Bit. 0: Crossbar disabled. All pins on Ports 0, 1, 2, and 3, are forced to Input mode. 1: Crossbar enabled. UNUSED. Read = 0, Write = don't care. T4EXE: T4EX Input Enable Bit. 0: T4EX unavailable at Port pin. 1: T4EX routed to Port pin. T4E: T4 Input Enable Bit. 0: T4 unavailable at Port pin. 1: T4 routed to Port pin. UART1E: UART1 I/O Enable Bit. 0: UART1 I/O unavailable at Port pins. 1: UART1 TX and RX routed to 2 Port pins. Reserved Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 18.8. XBR3: Port I/O Crossbar Register 3 R R R CTXOUT - - Bit7 Bit6 Bit5 Bit7: Bit6-4: Bit3: Bit2: Bit1: Bit0: R/W Bit4 R/W R/W R/W R/W Reset Value CP2E CNVST2E T3EXE T3E 00000000 Bit3 Bit2 Bit1 Bit0 SFR Address: 0xE4 SFR Page: F CTXOUT: CAN Transmit Pin (CTX) Output Mode. 0: CTX pin output mode is configured as open-drain. 1: CTX pin output mode is configured as push-pull. Reserved CP2E: CP2 Output Enable Bit. 0: CP2 unavailable at Port pin. 1: CP2 routed to Port pin. CNVST2E: ADC2 External Convert Start Input Enable Bit. 0: CNVST2 for ADC2 unavailable at Port pin. 1: CNVST2 for ADC2 routed to Port pin. T3EXE: T3EX Input Enable Bit. 0: T3EX unavailable at Port pin. 1: T3EX routed to Port pin. T3E: T3 Input Enable Bit. 0: T3 unavailable at Port pin. 1: T3 routed to Port pin. Rev. 1.3 213 C8051F060/1/2/3/4/5/6/7 Figure 18.9. P0: Port0 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P0.7 P0.6 P0.5 P0.4 P0.3 P0.2 P0.1 P0.0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-0: Bit Addressable SFR Address: 0x80 SFR Page: All Pages Bit0 P0.[7:0]: Port0 Output Latch Bits. (Write - Output appears on I/O pins per XBR0, XBR1, XBR2, and XBR3 Registers) 0: Logic Low Output. 1: Logic High Output (open if corresponding P0MDOUT.n bit = 0). (Read - Regardless of XBR0, XBR1, XBR2, and XBR3 Register settings). 0: P0.n pin is logic low. 1: P0.n pin is logic high. Figure 18.10. P0MDOUT: Port0 Output Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bit0 SFR Address: 0xA4 SFR Page: F Bits7-0: P0MDOUT.[7:0]: Port0 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Note: SDA, SCL, and RX0 (when UART0 is in Mode 0) and RX1 (when UART1 is in Mode 0) are always configured as Open-Drain when they appear on Port pins. 214 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 18.11. P1: Port1 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P1.7 P1.6 P1.5 P1.4 P1.3 P1.2 P1.1 P1.0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-0: Bit Addressable SFR Address: 0x90 SFR Page: All Pages Bit0 P1.[7:0]: Port1 Output Latch Bits. (Write - Output appears on I/O pins per XBR0, XBR1, XBR2, and XBR3 Registers) 0: Logic Low Output. 1: Logic High Output (open if corresponding P1MDOUT.n bit = 0). (Read - Regardless of XBR0, XBR1, XBR2, and XBR3 Register settings). 0: P1.n pin is logic low. 1: P1.n pin is logic high. Note: On the C8051F060/1/2/3, P1.[7:0] can be configured as inputs to ADC2 as AIN2.[7:0], in which case they are ‘skipped’ by the Crossbar assignment process and their digital input paths are disabled, depending on P1MDIN (See Figure 18.12). Note that in analog mode, the output mode of the pin is determined by the Port 1 latch and P1MDOUT (Figure 18.13). See Section “7. 10-Bit ADC (ADC2, C8051F060/1/2/3)” on page 87 for more information about ADC2. Figure 18.12. P1MDIN: Port1 Input Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 11111111 Bits7-0: Bit0 SFR Address: 0xAD SFR Page: F P1MDIN.[7:0]: Port 1 Input Mode Bits. 0: Port Pin is configured in Analog Input mode. The digital input path is disabled (a read from the Port bit will always return ‘0’). The weak pull-up on the pin is disabled. 1: Port Pin is configured in Digital Input mode. A read from the Port bit will return the logic level at the Pin. The state of the weak pull-up is determined by the WEAKPUD bit (XBR2.7, see Figure 18.7). Rev. 1.3 215 C8051F060/1/2/3/4/5/6/7 Figure 18.13. P1MDOUT: Port1 Output Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bit0 SFR Address: 0xA5 SFR Page: F Bits7-0: P1MDOUT.[7:0]: Port1 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Note: SDA, SCL, and RX0 (when UART0 is in Mode 0) and RX1 (when UART1 is in Mode 0) are always configured as Open-Drain when they appear on Port pins. Figure 18.14. P2: Port2 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P2.7 P2.6 P2.5 P2.4 P2.3 P2.2 P2.1 P2.0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bits7-0: 216 Bit Addressable SFR Address: 0xA0 SFR Page: All Pages Bit0 P2.[7:0]: Port2 Output Latch Bits. (Write - Output appears on I/O pins per XBR0, XBR1, XBR2, and XBR3 Registers) 0: Logic Low Output. 1: Logic High Output (open if corresponding P2MDOUT.n bit = 0). (Read - Regardless of XBR0, XBR1, XBR2, and XBR3 Register settings). 0: P2.n pin is logic low. 1: P2.n pin is logic high. Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 18.15. P2MDIN: Port2 Input Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 11111111 Bits7-0: Bit0 SFR Address: 0xAE SFR Page: F P2MDIN.[7:0]: Port 2 Input Mode Bits. 0: Port Pin is configured in Analog Input mode. The digital input path is disabled (a read from the Port bit will always return ‘0’). The weak pull-up on the pin is disabled. 1: Port Pin is configured in Digital Input mode. A read from the Port bit will return the logic level at the Pin. The state of the weak pull-up is determined by the WEAKPUD bit (XBR2.7, see Figure 18.7). Figure 18.16. P2MDOUT: Port2 Output Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bit0 SFR Address: 0xA6 SFR Page: F Bits7-0: P2MDOUT.[7:0]: Port2 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Note: SDA, SCL, and RX0 (when UART0 is in Mode 0) and RX1 (when UART1 is in Mode 0) are always configured as Open-Drain when they appear on Port pins. Rev. 1.3 217 C8051F060/1/2/3/4/5/6/7 Figure 18.17. P3: Port3 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P3.7 P3.6 P3.5 P3.4 P3.3 P3.2 P3.1 P3.0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit Addressable SFR Address: 0xB0 SFR Page: All Pages Bit0 Bits7-0: P3.[7:0]: Port3 Output Latch Bits. (Write - Output appears on I/O pins per XBR0, XBR1, XBR2, and XBR3 Registers) 0: Logic Low Output. 1: Logic High Output (open if corresponding P3MDOUT.n bit = 0). (Read - Regardless of XBR0, XBR1, XBR2, and XBR3 Register settings). 0: P3.n pin is logic low. 1: P3.n pin is logic high. Note: Although P3 is not brought out to pins on the C8051F061/3/5/7 devices, the Port Data register is still present and can be used by software. See “Configuring Ports which are not Pinned Out” on page 219. Figure 18.18. P3MDOUT: Port3 Output Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: 218 P3MDOUT.[7:0]: Port3 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Rev. 1.3 Bit0 SFR Address: 0xA7 SFR Page: F C8051F060/1/2/3/4/5/6/7 18.2. Ports 4 through 7 (C8051F060/2/4/6 only) All Port pins on Ports 4 through 7 can be accessed as General-Purpose I/O (GPIO) pins by reading and writing the associated Port Data registers (See Figure 18.19, Figure 18.21, Figure 18.23, and Figure 18.25), a set of SFRs which are byte-addressable. Note that Port 4 has only three pins: P4.5, P4.6, and P4.7. Note also that the Port 4, 5, 6, and 7 registers are located on SFR Page F. The SFRPAGE register must be set to 0x0F to access these Port registers. A Read of a Port Data register (or Port bit) will always return the logic state present at the pin itself, regardless of whether the Crossbar has allocated the pin for peripheral use or not. An exception to this occurs during the execution of a read-modify-write instruction (ANL, ORL, XRL, CPL, INC, DEC, DJNZ, JBC, CLR, SETB, and the bitwise MOV write operation). During the read cycle of the read-modify-write instruction, it is the contents of the Port Data register, not the state of the Port pins themselves, which is read. 18.2.1. Configuring Ports which are not Pinned Out Although P3, P4, P5, P6, and P7 are not brought out to pins on the C8051F061/3/5/7 devices, the Port Data registers are still present and can be used by software. Because the digital input paths also remain active, it is recommended that these pins not be left in a ‘floating’ state in order to avoid unnecessary power dissipation arising from the inputs floating to non-valid logic levels. This condition can be prevented by any of the following: 1. Leave the weak pull-up devices enabled by setting WEAKPUD (XBR2.7) to a logic 0. 2. Configure the output modes of P3, P4, P5, P6, and P7 to “Push-Pull” by writing 0xFF to the associated output mode register (PnMDOUT). 3. Force the output states of P3, P4, P5, P6, and P7 to logic 0 by writing zeros to the Port Data registers: P3 = 0x00, P4 = 0x00, P5 = 0x00, P6= 0x00, and P7 = 0x00. 18.2.2. Configuring the Output Modes of the Port Pins The output mode of each port pin can be configured to be either Open-Drain or Push-Pull. In the Push-Pull configuration, a logic 0 in the associated bit in the Port Data register will cause the Port pin to be driven to GND, and a logic 1 will cause the Port pin to be driven to VDD. In the Open-Drain configuration, a logic 0 in the associated bit in the Port Data register will cause the Port pin to be driven to GND, and a logic 1 will cause the Port pin to assume a high-impedance state. The Open-Drain configuration is useful to prevent contention between devices in systems where the Port pin participates in a shared interconnection in which multiple outputs are connected to the same physical wire. The output modes of the Port pins on Ports 4 through 7 are determined by the bits in their respective PnMDOUT Output Mode Registers. Each bit in PnMDOUT controls the output mode of its corresponding port pin (see Figure 18.20, Figure 18.22, Figure 18.24, and Figure 18.26). For example, to place Port pin 5.3 in push-pull mode (digital output), set P5MDOUT.3 to logic 1. All port pins default to open-drain mode upon device reset. 18.2.3. Configuring Port Pins as Digital Inputs A Port pin is configured as a digital input by setting its output mode to “Open-Drain” and writing a logic 1 to the associated bit in the Port Data register. For example, P7.7 is configured as a digital input by setting P7MDOUT.7 to a logic 0 and P7.7 to a logic 1. 18.2.4. Weak Pull-ups By default, each Port pin has an internal weak pull-up device enabled which provides a resistive connection (about 100 k) between the pin and VDD. The weak pull-up devices can be globally disabled by writ- Rev. 1.3 219 C8051F060/1/2/3/4/5/6/7 ing a logic 1 to the Weak Pull-up Disable bit, (WEAKPUD, XBR2.7). The weak pull-up is automatically deactivated on any pin that is driving a logic 0; that is, an output pin will not contend with its own pull-up device. 18.2.5. External Memory Interface If the External Memory Interface is enabled on the High ports and an off-chip MOVX operation occurs, the External Memory Interface will control the output states of the affected Port pins during the execution phase of the MOVX instruction, regardless of the settings of the Port Data registers. The output configuration of the Port pins is not affected by the EMIF operation, except that Read operations will explicitly disable the output drivers on the Data Bus during the MOVX execution. See Section “17. External Data Memory Interface and On-Chip XRAM” on page 187 for more information about the External Memory Interface. 220 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 18.19. P4: Port4 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P4.7 P4.6 P4.5 - - - - - 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit Addressable SFR Address: 0xC8 SFR Page: F Bit0 Bits7-5: P4.[7:5]: Port4 Output Latch Bits. Write - Output appears on I/O pins. 0: Logic Low Output. 1: Logic High Output (open, if corresponding P4MDOUT.n bit = 0). See Figure 18.20. Read - Returns states of I/O pins. 0: P4.n pin is logic low. 1: P4.n pin is logic high. Bits 4-0: Reserved. Write to ‘11111’. Note: P4.7 (/WR), P4.6 (/RD), and P4.5 (ALE) can be driven by the External Data Memory Interface. See Section “17. External Data Memory Interface and On-Chip XRAM” on page 187 for more information. Figure 18.20. P4MDOUT: Port4 Output Mode Register R/W Bit7 R/W Bit6 R/W Bit5 R/W R/W R/W R/W R/W Reset Value - - - - - 00000000 Bit4 Bit3 Bit2 Bit1 Bit0 SFR Address: 0x9C SFR Page: F Bits7-5: P4MDOUT.[7:5]: Port4 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Bits 4-0: Reserved. Write to ‘00000’. Rev. 1.3 221 C8051F060/1/2/3/4/5/6/7 Figure 18.21. P5: Port5 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P5.7 P5.6 P5.5 P5.4 P5.3 P5.2 P5.1 P5.0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit Addressable SFR Address: 0xD8 SFR Page: F Bit0 Bits7-0: P5.[7:0]: Port5 Output Latch Bits. Write - Output appears on I/O pins. 0: Logic Low Output. 1: Logic High Output (open, if corresponding P5MDOUT bit = 0). See Figure 18.22. Read - Returns states of I/O pins. 0: P5.n pin is logic low. 1: P5.n pin is logic high. Note: P5.[7:0] can be driven by the External Data Memory Interface (as Address[15:8] in Non-multiplexed mode). See Section “17. External Data Memory Interface and On-Chip XRAM” on page 187 for more information about the External Memory Interface. Figure 18.22. P5MDOUT: Port5 Output Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: 222 P5MDOUT.[7:0]: Port5 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Rev. 1.3 Bit0 SFR Address: 0x9D SFR Page: F C8051F060/1/2/3/4/5/6/7 Figure 18.23. P6: Port6 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P6.7 P6.6 P6.5 P6.4 P6.3 P6.2 P6.1 P6.0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit Addressable SFR Address: 0xE8 SFR Page: F Bit0 Bits7-0: P6.[7:0]: Port6 Output Latch Bits. Write - Output appears on I/O pins. 0: Logic Low Output. 1: Logic High Output (open, if corresponding P6MDOUT bit = 0). See Figure 18.24. Read - Returns states of I/O pins. 0: P6.n pin is logic low. 1: P6.n pin is logic high. Note: P6.[7:0] can be driven by the External Data Memory Interface (as Address[15:8] in Multiplexed mode, or as Address[7:0] in Non-multiplexed mode). See Section “17. External Data Memory Interface and On-Chip XRAM” on page 187 for more information about the External Memory Interface. Figure 18.24. P6MDOUT: Port6 Output Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0x9E SFR Page: F P6MDOUT.[7:0]: Port6 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Rev. 1.3 223 C8051F060/1/2/3/4/5/6/7 Figure 18.25. P7: Port7 Data Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P7.7 P7.6 P7.5 P7.4 P7.3 P7.2 P7.1 P7.0 11111111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit Addressable SFR Address: 0xF8 SFR Page: F Bit0 Bits7-0: P7.[7:0]: Port7 Output Latch Bits. Write - Output appears on I/O pins. 0: Logic Low Output. 1: Logic High Output (open, if corresponding P7MDOUT bit = 0). See Figure 18.26. Read - Returns states of I/O pins. 0: P7.n pin is logic low. 1: P7.n pin is logic high. Note: P7.[7:0] can be driven by the External Data Memory Interface (as AD[7:0] in Multiplexed mode, or as D[7:0] in Non-multiplexed mode). See Section “17. External Data Memory Interface and On-Chip XRAM” on page 187 for more information about the External Memory Interface. Figure 18.26. P7MDOUT: Port7 Output Mode Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: 224 P7MDOUT.[7:0]: Port7 Output Mode Bits. 0: Port Pin output mode is configured as Open-Drain. 1: Port Pin output mode is configured as Push-Pull. Rev. 1.3 Bit0 SFR Address: 0x9F SFR Page: F C8051F060/1/2/3/4/5/6/7 19. Controller Area Network (CAN0, C8051F060/1/2/3) IMPORTANT DOCUMENTATION NOTE: The Bosch CAN Controller is integrated in the C8051F060/1/2/3 devices. This section of the data sheet gives a description of the CAN controller as an overview and offers a description of how the Silicon Labs CIP-51 MCU interfaces with the on-chip Bosch CAN controller. In order to use the CAN controller, please refer to Bosch’s C_CAN User’s Manual (revision 1.2) as an accompanying manual to Silicon Labs’ C8051F060/1/2/3/4/5/6/7 Data sheet. The C8051F060/1/2/3 family of devices feature a Control Area Network (CAN) controller that enables serial communication using the CAN protocol. Silicon Labs CAN controller facilitates communication on a CAN network in accordance with the Bosch specification 2.0A (basic CAN) and 2.0B (full CAN). The CAN controller consists of a CAN Core, Message RAM (separate from the CIP-51 RAM), a message handler state machine, and control registers. Silicon Labs CAN is a protocol controller and does not provide physical layer drivers (i.e., transceivers). Figure 19.2 shows an example typical configuration on a CAN bus. Silicon Labs CAN operates at bit rates of up to 1 Mbit/second, though this can be limited by the physical layer chosen to transmit data on the CAN bus. The CAN processor has 32 Message Objects that can be configured to transmit or receive data. Incoming data, message objects and their identifier masks are stored in the CAN message RAM. All protocol functions for transmission of data and acceptance filtering is performed by the CAN controller and not by the CIP-51 MCU. In this way, minimal CPU bandwidth is needed to use CAN communication. The CIP-51 configures the CAN controller, accesses received data, and passes data for transmission via Special Function Registers (SFR) in the CIP-51. The CAN controller’s clock (fsys, or CAN_CLK in the C_CAN User’s Guide) is equal to the CIP-51 MCU’s clock (SYSCLK). Rev. 1.3 225 C8051F060/1/2/3/4/5/6/7 Figure 19.1. CAN Controller Diagram Figure 19.2. Typical CAN Bus Configuration 226 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 19.1. Bosch CAN Controller Operation The CAN Controller featured in the C8051F060/1/2/3 devices is a full implementation of Bosch’s full CAN module and fully complies with CAN specification 2.0B. The function and use of the CAN Controller is detailed in the Bosch CAN User’s Guide. The User’s Guide should be used as a reference to configure and use the CAN controller. This Silicon Labs datasheet describes how to access the CAN controller. The CAN Control Register (CAN0CN), CAN Test Register (CAN0TST), and CAN Status Register (CAN0STA) in the CAN controller can be accessed directly or indirectly via CIP-51 SFRs. All other CAN registers must be accessed via an indirect indexing method. See “Using CAN0ADR, CAN0DATH, and CANDATL To Access CAN Registers” on page 229. Rev. 1.3 227 C8051F060/1/2/3/4/5/6/7 19.2. CAN Registers CAN registers are classified as follows: 1. CAN Controller Protocol Registers: CAN control, interrupt, error control, bus status, test modes. 2. Message Object Interface Registers: Used to configure 32 Message Objects, send and receive data to and from Message Objects. The C8051 MCU accesses the CAN message RAM via the Message Object Interface Registers. Upon writing a message object number to an IF1 or IF2 Command Request Register, the contents of the associated Interface Registers (IF1 or IF2) will be transferred to or from the message object in CAN RAM. 3. Message Handler Registers: These read only registers are used to provide information to the CIP-51 MCU about the message objects (MSGVLD flags, Transmission Request Pending, New Data Flags) and Interrupts Pending (which Message Objects have caused an interrupt or status interrupt condition). 4. C8051 MCU Special Function Registers (SFR): Five registers located in the C8051 MCU memory map that allow direct access to certain CAN Controller Protocol Registers, and Indexed indirect access to all CAN registers. 19.2.1. CAN Controller Protocol Registers The CAN Control Protocol Registers are used to configure the CAN controller, process interrupts, monitor bus status, and place the controller in test modes. The CAN controller protocol registers are accessible using C8051 MCU SFRs by an indexed method, and some can be accessed directly by addressing the SFRs in the C8051 SFR map for convenience. The registers are: CAN Control Register (CAN0CN), CAN Status Register (CAN0STA), CAN Test Register (CAN0TST), Error Counter Register, Bit Timing Register, and the Baud Rate Prescaler (BRP) Extension Register. CAN0STA, CAN0CN, and CAN0TST can be accessed via C8051 MCU SFRs. All others are accessed indirectly using the CAN address indexed method via CAN0ADR, CAN0DATH, and CAN0DATL. Please refer to the Bosch CAN User’s Guide for information on the function and use of the CAN Control Protocol Registers. 19.2.2. Message Object Interface Registers There are two sets of Message Object Interface Registers used to configure the 32 Message Objects that transmit and receive data to and from the CAN bus. Message objects can be configured for transmit or receive, and are assigned arbitration message identifiers for acceptance filtering by all CAN nodes. Message Objects are stored in Message RAM, and are accessed and configured using the Message Object Interface Registers. These registers are accessed via the C8051’s CAN0ADR and CAN0DAT registers using the indirect indexed address method. Please refer to the Bosch CAN User’s Guide for information on the function and use of the Message Object Interface Registers. 19.2.3. Message Handler Registers The Message Handler Registers are read only registers. Their flags can be read via the indexed access method with CAN0ADR, CAN0DATH, and CAN0DATL. The message handler registers provide interrupt, error, transmit/receive requests, and new data information. 228 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Please refer to the Bosch CAN User’s Guide for information on the function and use of the Message Handler Registers. 19.2.4. CIP-51 MCU Special Function Registers C8051F060/1/2/3 peripherals are modified, monitored, and controlled using Special Function Registers (SFRs). Most of the CAN Controller registers cannot be accessed directly using the SFRs. Three of the CAN Controller’s registers may be accessed directly with SFRs. All other CAN Controller registers are accessed indirectly using three CIP-51 MCU SFRs: the CAN Data Registers (CAN0DATH and CAN0DATL) and CAN Address Register (CAN0ADR). In this way, there are a total of five CAN registers used to configure and run the CAN Controller. 19.2.5. Using CAN0ADR, CAN0DATH, and CANDATL To Access CAN Registers Each CAN Controller Register has an index number (see Table below). The CAN register address space is 128 words (256 bytes). A CAN register is accessed via the CAN Data Registers (CAN0DATH and CAN0DATL) when a CAN register’s index number is placed into the CAN Address Register (CAN0ADR). For example, if the Bit Timing Register is to be configured with a new value, CAN0ADR is loaded with 0x03. The low byte of the desired value is accessed using CAN0DATL and the high byte of the bit timing register is accessed using CAN0DATH. CAN0DATL is bit addressable for convenience. To load the value 0x2304 into the Bit Timing Register: CAN0ADR = 0x03; CAN0DATH = 0x23; CAN0DATL = 0x04; // Load Bit Timing Register’s index (Table 18.1) // Move the upper byte into data reg high byte // Move the lower byte into data reg low byte Note: CAN0CN, CAN0STA, and CAN0TST may be accessed either by using the index method, or by direct access with the CIP-51 MCU SFRs. CAN0CN is located at SFR location 0xF8/SFR page 1 (Figure 19.6), CAN0TST at 0xDB/SFR page 1 (Figure 19.7), and CAN0STA at 0xC0/SFR page 1 (Figure 19.8). 19.2.6. CAN0ADR Autoincrement Feature For ease of programming message objects, CAN0ADR features autoincrementing for the index ranges 0x08 to 0x12 (Interface Registers 1) and 0x20 to 0x2A (Interface Registers 2). When the CAN0ADR register has an index in these ranges, the CAN0ADR will autoincrement by 1 to point to the next CAN register 16-bit word upon a read/write of CAN0DATL. This speeds programming of the frequently programmed interface registers when configuring message objects. NOTE: Table below supersedes Figure 5 in section 3, “Programmer’s Model” of the Bosch CAN User’s Guide. Table 19.1. CAN Register Index and Reset Values CAN Register Index Register name Reset Value 0x00 CAN Control Register 0x0001 Accessible in CIP-51 SFR Map 0x01 Status Register 0x0000 Accessible in CIP-51 SFR Map 0x02 Error Register 0x03 Bit Timing Register Notes 0x0000 Read Only 0x2301 Write Enabled by CCE Bit in CAN0CN Rev. 1.3 229 C8051F060/1/2/3/4/5/6/7 Table 19.1. CAN Register Index and Reset Values (Continued) CAN Register Index Register name 0x04 Interrupt Register 0x05 Test Register 0x06 BRP Extension Register 0x0000 Write Enabled by TEST bit in CAN0CN 0x08 IF1 Command Request 0x0001 CAN0ADR autoincrements in IF1 index space (0x08 - 0x12) upon write to CAN0DATL 0x09 IF1 Command Mask 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x0A IF1 Mask 1 0xFFFF CAN0ADR autoincrement upon write to CAN0DATL 0x0B IF1 Mask 2 0xFFFF CAN0ADR autoincrement upon write to CAN0DATL 0x0C IF1 Arbitration 1 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x0D IF1 Arbitration 2 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x0E IF1 Message Control 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x0F IF1 Data A1 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x10 IF1 Data A2 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x11 IF1 Data B1 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x12 IF1 Data B2 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x20 IF2 Command Request 0x0001 CAN0ADR autoincrements in IF1 index space (0x08 - 0x12) upon write to CAN0DATL 0x21 IF2 Command Mask 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x22 IF2 Mask 1 0xFFFF CAN0ADR autoincrement upon write to CAN0DATL 0x23 IF2 Mask 2 0xFFFF CAN0ADR autoincrement upon write to CAN0DATL 0x24 IF2 Arbitration 1 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x25 IF2 Arbitration 2 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x26 IF2 Message Control 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x27 IF2 Data A1 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x28 IF2 Data A2 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x29 IF2 Data B1 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x2A IF2 Data B2 0x0000 CAN0ADR autoincrement upon write to CAN0DATL 0x40 Transmission Request 1 0x0000 Transmission request flags for message objects (read only) 0x41 Transmission Request 2 0x0000 Transmission request flags for message objects (read only) 0x48 New Data 1 0x0000 New Data flags for message objects (read only) 0x49 New Data 2 0x0000 New Data flags for message objects (read only) 0x50 Interrupt Pending 1 0x0000 Interrupt pending flags for message objects (read only) 0x51 Interrupt Pending 2 0x0000 Interrupt pending flags for message objects (read only) 0x58 Message Valid 1 230 Reset Value Notes 0x0000 Read Only 0x0000 Bit 7 (RX) is determined by CAN bus 0x0000 Message valid flags for message objects (read only) Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Table 19.1. CAN Register Index and Reset Values (Continued) CAN Register Index Register name Reset Value 0x59 Message Valid 2 0x0000 Message valid flags for message objects (read only) Notes Figure 19.3. CAN0DATH: CAN Data Access Register High Byte R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bit7-0: Bit0 SFR Address: 0xD9 SFR Page: 1 CAN0DATH: CAN Data Access Register High Byte. The CAN0DAT Registers are used to read/write register values and data to and from the CAN Registers pointed to with the index number in the CAN0ADR Register. The CAN0ADR Register is used to point the [CAN0DATH:CAN0DATL] to a desired CAN Register. The desired CAN Register’s index number is moved into CAN0ADR. The CAN0DAT Register can then read/write to and from the CAN Register. Figure 19.4. CAN0DATL: CAN Data Access Register Low Byte R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000001 Bit7-0: Bit0 SFR Address: 0xD8 SFR Page: 1 CAN0DATL: CAN Data Access Register Low Byte. The CAN0DAT Registers are used to read/write register values and data to and from the CAN Registers pointed to with the index number in the CAN0ADR Register. The CAN0ADR Register is used to point the [CAN0DATH:CAN0DATL] to a desired CAN Register. The desired CAN Register’s index number is moved into CAN0ADR. The CAN0DAT Register can then read/write to and from the CAN Register. Rev. 1.3 231 C8051F060/1/2/3/4/5/6/7 Figure 19.5. CAN0ADR: CAN Address Index Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bit7-0: Bit0 SFR Address: 0xDA SFR Page: 1 CAN0ADR: CAN Address Index Register. The CAN0ADR Register is used to point the [CAN0DATH:CAN0DATL] to a desired CAN Register. The desired CAN Register’s index number is moved into CAN0ADR. The CAN0DAT Register can then read/write to and from the CAN Register. Note: When the value of CAN0ADR is 0x08-0x12 and 0x20-2A (IF1 and IF2 registers), this register will autoincrement by 1 upon a write to CAN0DATL. See Section “19.2.6. CAN0ADR Autoincrement Feature” on page 229. All CAN registers’ functions/definitions are listed and described in the Bosch CAN User’s Guide. Figure 19.6. CAN0CN: CAN Control Register R/W R/W R/W R R/W R/W R/W R/W * * * CANIF * * * * Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit 4: Reset Value Bit0 SFR Address: 0xF8 SFR Page: 1 CANIF: CAN Interrupt Flag. Write = don’t care. 0: CAN interrupt has not occured. 1: CAN interrupt has occured and is active. CANIF is controlled by the CAN controller and is cleared by hardware once all interrupt conditions have been cleared in the CAN controller. See section 3.4.1 in the Bosch CAN User’s Guide (page 24) for more information concerning CAN controller interrupts. *All CAN registers’ functions/definitions are listed and described in the Bosch CAN User’s Guide with the exception of the CANIF bit. This register may be accessed directly in the CIP-51 SFR register space, or through the indirect, index method (See Section “19.2.5. Using CAN0ADR, CAN0DATH, and CANDATL To Access CAN Registers” on page 229). 232 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 19.7. CAN0TST: CAN Test Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Please see the Bosch CAN User’s Guide for a complete definition of this register Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 SFR Address: 0xDB SFR Page: 1 All CAN registers’ functions/definitions are listed and described in the Bosch CAN User’s Guide. This register may be accessed directly in the CIP-51 SFR register space, or through the indirect, index method (See Section “19.2.5. Using CAN0ADR, CAN0DATH, and CANDATL To Access CAN Registers” on page 229). Figure 19.8. CAN0STA: CAN Status Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Please see the Bosch CAN User’s Guide for a complete definition of this register Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 SFR Address: 0xC0 SFR Page: 1 All CAN registers’ functions/definitions are listed and described in the Bosch CAN User’s Guide. This register may be accessed directly in the CIP-51 SFR register space, or through the indirect, index method (See Section “19.2.5. Using CAN0ADR, CAN0DATH, and CANDATL To Access CAN Registers” on page 229). Rev. 1.3 233 C8051F060/1/2/3/4/5/6/7 234 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 20. System Management BUS / I2C BUS (SMBUS0) The SMBus0 I/O interface is a two-wire, bi-directional serial bus. SMBus0 is compliant with the System Management Bus Specification, version 1.1, and compatible with the I2C serial bus. Reads and writes to the interface by the system controller are byte oriented with the SMBus0 interface autonomously controlling the serial transfer of the data. A method of extending the clock-low duration is available to accommodate devices with different speed capabilities on the same bus. SMBus0 may operate as a master and/or slave, and may function on a bus with multiple masters. SMBus0 provides control of SDA (serial data), SCL (serial clock) generation and synchronization, arbitration logic, and START/STOP control and generation. Figure 20.1. SMBus0 Block Diagram Rev. 1.3 235 C8051F060/1/2/3/4/5/6/7 Figure 20.2 shows a typical SMBus configuration. The SMBus0 interface will work at any voltage between 3.0 V and 5.0 V and different devices on the bus may operate at different voltage levels. The bi-directional SCL (serial clock) and SDA (serial data) lines must be connected to a positive power supply voltage through a pull-up resistor or similar circuit. Every device connected to the bus must have an open-drain or open-collector output for both the SCL and SDA lines, so that both are pulled high when the bus is free. The maximum number of devices on the bus is limited only by the requirement that the rise and fall times on the bus will not exceed 300 ns and 1000 ns, respectively. Figure 20.2. Typical SMBus Configuration 20.1. Supporting Documents It is assumed the reader is familiar with or has access to the following supporting documents: 1. The I2C-bus and how to use it (including specifications), Philips Semiconductor. 2. The I2C-Bus Specification -- Version 2.0, Philips Semiconductor. 3. System Management Bus Specification -- Version 1.1, SBS Implementers Forum. 20.2. SMBus Protocol Two types of data transfers are possible: data transfers from a master transmitter to an addressed slave receiver (WRITE), and data transfers from an addressed slave transmitter to a master receiver (READ). The master device initiates both types of data transfers and provides the serial clock pulses on SCL. Note: multiple master devices on the same bus are supported. If two or more masters attempt to initiate a data transfer simultaneously, an arbitration scheme is employed with a single master always winning the arbitration. Note that it is not necessary to specify one device as the master in a system; any device who transmits a START and a slave address becomes the master for that transfer. A typical SMBus transaction consists of a START condition followed by an address byte (Bits7-1: 7-bit slave address; Bit0: R/W direction bit), one or more bytes of data, and a STOP condition. Each byte that is received (by a master or slave) must be acknowledged (ACK) with a low SDA during a high SCL (see Figure 20.3). If the receiving device does not ACK, the transmitting device will read a “not acknowledge” (NACK), which is a high SDA during a high SCL. 236 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 The direction bit (R/W) occupies the least-significant bit position of the address. The direction bit is set to logic 1 to indicate a "READ" operation and cleared to logic 0 to indicate a "WRITE" operation. All transactions are initiated by a master, with one or more addressed slave devices as the target. The master generates the START condition and then transmits the slave address and direction bit. If the transaction is a WRITE operation from the master to the slave, the master transmits the data a byte at a time waiting for an ACK from the slave at the end of each byte. For READ operations, the slave transmits the data waiting for an ACK from the master at the end of each byte. At the end of the data transfer, the master generates a STOP condition to terminate the transaction and free the bus. Figure 20.3 illustrates a typical SMBus transaction. Figure 20.3. SMBus Transaction 20.2.1. Arbitration A master may start a transfer only if the bus is free. The bus is free after a STOP condition or after the SCL and SDA lines remain high for a specified time (see Section 20.2.4). In the event that two or more devices attempt to begin a transfer at the same time, an arbitration scheme is employed to force one master to give up the bus. The master devices continue transmitting until one attempts a HIGH while the other transmits a LOW. Since the bus is open-drain, the bus will be pulled LOW. The master attempting the HIGH will detect a LOW SDA and give up the bus. The winning master continues its transmission without interruption; the losing master becomes a slave and receives the rest of the transfer. This arbitration scheme is nondestructive: one device always wins, and no data is lost. 20.2.2. Clock Low Extension SMBus provides a clock synchronization mechanism, similar to I2C, which allows devices with different speed capabilities to coexist on the bus. A clock-low extension is used during a transfer in order to allow slower slave devices to communicate with faster masters. The slave may temporarily hold the SCL line LOW to extend the clock low period, effectively decreasing the serial clock frequency. 20.2.3. SCL Low Timeout If the SCL line is held low by a slave device on the bus, no further communication is possible. Furthermore, the master cannot force the SCL line high to correct the error condition. To solve this problem, the SMBus protocol specifies that devices participating in a transfer must detect any clock cycle held low longer than 25 ms as a “timeout” condition. Devices that have detected the timeout condition must reset the communication no later than 10 ms after detecting the timeout condition. 20.2.4. SCL High (SMBus Free) Timeout The SMBus specification stipulates that if the SCL and SDA lines remain high for more that 50 μs, the bus is designated as free. If an SMBus device is waiting to generate a Master START, the START will be generated following the bus free timeout. Rev. 1.3 237 C8051F060/1/2/3/4/5/6/7 20.3. SMBus Transfer Modes The SMBus0 interface may be configured to operate as a master and/or a slave. At any particular time, the interface will be operating in one of the following modes: Master Transmitter, Master Receiver, Slave Transmitter, or Slave Receiver. See Table 20.1 for transfer mode status decoding using the SMB0STA status register. The following mode descriptions illustrate an interrupt-driven SMBus0 application; SMBus0 may alternatively be operated in polled mode. 20.3.1. Master Transmitter Mode Serial data is transmitted on SDA while the serial clock is output on SCL. SMBus0 generates a START condition and then transmits the first byte containing the address of the target slave device and the data direction bit. In this case the data direction bit (R/W) will be logic 0 to indicate a "WRITE" operation. The SMBus0 interface transmits one or more bytes of serial data, waiting for an acknowledge (ACK) from the slave after each byte. To indicate the end of the serial transfer, SMBus0 generates a STOP condition. Figure 20.4. Typical Master Transmitter Sequence 20.3.2. Master Receiver Mode Serial data is received on SDA while the serial clock is output on SCL. The SMBus0 interface generates a START followed by the first data byte containing the address of the target slave and the data direction bit. In this case the data direction bit (R/W) will be logic 1 to indicate a "READ" operation. The SMBus0 interface receives serial data from the slave and generates the clock on SCL. After each byte is received, SMBus0 generates an ACK or NACK depending on the state of the AA bit in register SMB0CN. SMBus0 generates a STOP condition to indicate the end of the serial transfer. Figure 20.5. Typical Master Receiver Sequence 238 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 20.3.3. Slave Transmitter Mode Serial data is transmitted on SDA while the serial clock is received on SCL. The SMBus0 interface receives a START followed by data byte containing the slave address and direction bit. If the received slave address matches the address held in register SMB0ADR, the SMBus0 interface generates an ACK. SMBus0 will also ACK if the general call address (0x00) is received and the General Call Address Enable bit (SMB0ADR.0) is set to logic 1. In this case the data direction bit (R/W) will be logic 1 to indicate a "READ" operation. The SMBus0 interface receives the clock on SCL and transmits one or more bytes of serial data, waiting for an ACK from the master after each byte. SMBus0 exits slave mode after receiving a STOP condition from the master. Figure 20.6. Typical Slave Transmitter Sequence 20.3.4. Slave Receiver Mode Serial data is received on SDA while the serial clock is received on SCL. The SMBus0 interface receives a START followed by data byte containing the slave address and direction bit. If the received slave address matches the address held in register SMB0ADR, the interface generates an ACK. SMBus0 will also ACK if the general call address (0x00) is received and the General Call Address Enable bit (SMB0ADR.0) is set to logic 1. In this case the data direction bit (R/W) will be logic 0 to indicate a "WRITE" operation. The SMBus0 interface receives one or more bytes of serial data; after each byte is received, the interface transmits an ACK or NACK depending on the state of the AA bit in SMB0CN. SMBus0 exits Slave Rev. 1.3 239 C8051F060/1/2/3/4/5/6/7 Receiver Mode after receiving a STOP condition from the master. Figure 20.7. Typical Slave Receiver Sequence 240 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 20.4. SMBus Special Function Registers The SMBus0 serial interface is accessed and controlled through five SFRs: SMB0CN Control Register, SMB0CR Clock Rate Register, SMB0ADR Address Register, SMB0DAT Data Register and SMB0STA Status Register. The five special function registers related to the operation of the SMBus0 interface are described in the following sections. 20.4.1. Control Register The SMBus0 Control register SMB0CN is used to configure and control the SMBus0 interface. All of the bits in the register can be read or written by software. Two of the control bits are also affected by the SMBus0 hardware. The Serial Interrupt flag (SI, SMB0CN.3) is set to logic 1 by the hardware when a valid serial interrupt condition occurs. It can only be cleared by software. The Stop flag (STO, SMB0CN.4) is set to logic 1 by software. It is cleared to logic 0 by hardware when a STOP condition is detected on the bus. Setting the ENSMB flag to logic 1 enables the SMBus0 interface. Clearing the ENSMB flag to logic 0 disables the SMBus0 interface and removes it from the bus. Momentarily clearing the ENSMB flag and then resetting it to logic 1 will reset SMBus0 communication. However, ENSMB should not be used to temporarily remove a device from the bus since the bus state information will be lost. Instead, the Assert Acknowledge (AA) flag should be used to temporarily remove the device from the bus (see description of AA flag below). Setting the Start flag (STA, SMB0CN.5) to logic 1 will put SMBus0 in a master mode. If the bus is free, SMBus0 will generate a START condition. If the bus is not free, SMBus0 waits for a STOP condition to free the bus and then generates a START condition after a 5 μs delay per the SMB0CR value (In accordance with the SMBus protocol, the SMBus0 interface also considers the bus free if the bus is idle for 50 μs and no STOP condition was recognized). If STA is set to logic 1 while SMBus0 is in master mode and one or more bytes have been transferred, a repeated START condition will be generated. When the Stop flag (STO, SMB0CN.4) is set to logic 1 while the SMBus0 interface is in master mode, the interface generates a STOP condition. In a slave mode, the STO flag may be used to recover from an error condition. In this case, a STOP condition is not generated on the bus, but the SMBus hardware behaves as if a STOP condition has been received and enters the "not addressed" slave receiver mode. Note that this simulated STOP will not cause the bus to appear free to SMBus0. The bus will remain occupied until a STOP appears on the bus or a Bus Free Timeout occurs. Hardware automatically clears the STO flag to logic 0 when a STOP condition is detected on the bus. The Serial Interrupt flag (SI, SMB0CN.3) is set to logic 1 by hardware when the SMBus0 interface enters one of 27 possible states. If interrupts are enabled for the SMBus0 interface, an interrupt request is generated when the SI flag is set. The SI flag must be cleared by software. Important Note: If SI is set to logic 1 while the SCL line is low, the clock-low period of the serial clock will be stretched and the serial transfer is suspended until SI is cleared to logic 0. A high level on SCL is not affected by the setting of the SI flag. The Assert Acknowledge flag (AA, SMB0CN.2) is used to set the level of the SDA line during the acknowledge clock cycle on the SCL line. Setting the AA flag to logic 1 will cause an ACK (low level on SDA) to be sent during the acknowledge cycle if the device has been addressed. Setting the AA flag to logic 0 will cause a NACK (high level on SDA) to be sent during acknowledge cycle. After the transmission of a byte in slave mode, the slave can be temporarily removed from the bus by clearing the AA flag. The slave's own address and general call address will be ignored. To resume operation on the bus, the AA flag must be reset to logic 1 to allow the slave's address to be recognized. Rev. 1.3 241 C8051F060/1/2/3/4/5/6/7 Setting the SMBus0 Free Timer Enable bit (FTE, SMB0CN.1) to logic 1 enables the timer in SMB0CR. When SCL goes high, the timer in SMB0CR counts up. A timer overflow indicates a free bus timeout: if SMBus0 is waiting to generate a START, it will do so after this timeout. The bus free period should be less than 50 μs (see Figure 20.9, SMBus0 Clock Rate Register). When the TOE bit in SMB0CN is set to logic 1, Timer 4 is used to detect SCL low timeouts. If Timer 4 is enabled (see Section “24.2. Timer 2, Timer 3, and Timer 4” on page 295), Timer 4 is forced to reload when SCL is high, and forced to count when SCL is low. With Timer 4 enabled and configured to overflow after 25 ms (and TOE set), a Timer 4 overflow indicates a SCL low timeout; the Timer 4 interrupt service routine 242 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 can then be used to reset SMBus0 communication in the event of an SCL low timeout. Figure 20.8. SMB0CN: SMBus0 Control Register R R/W R/W R/W R/W R/W R/W R/W Reset Value BUSY ENSMB STA STO SI AA FTE TOE 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Bit Addressable SFR Address: 0xC0 SFR Page: 0 Bit0 BUSY: Busy Status Flag. 0: SMBus0 is free. 1: SMBus0 is busy. ENSMB: SMBus Enable. This bit enables/disables the SMBus serial interface. 0: SMBus0 disabled. 1: SMBus0 enabled. STA: SMBus Start Flag. 0: No START condition is transmitted. 1: When operating as a master, a START condition is transmitted if the bus is free. (If the bus is not free, the START is transmitted after a STOP is received.) If STA is set after one or more bytes have been transmitted or received and before a STOP is received, a repeated START condition is transmitted. STO: SMBus Stop Flag. 0: No STOP condition is transmitted. 1: Setting STO to logic 1 causes a STOP condition to be transmitted. When a STOP condition is received, hardware clears STO to logic 0. If both STA and STO are set, a STOP condition is transmitted followed by a START condition. In slave mode, setting the STO flag causes SMBus to behave as if a STOP condition was received. SI: SMBus Serial Interrupt Flag. This bit is set by hardware when one of 27 possible SMBus0 states is entered. (Status code 0xF8 does not cause SI to be set.) When the SI interrupt is enabled, setting this bit causes the CPU to vector to the SMBus interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. AA: SMBus Assert Acknowledge Flag. This bit defines the type of acknowledge returned during the acknowledge cycle on the SCL line. 0: A "not acknowledge" (high level on SDA) is returned during the acknowledge cycle. 1: An "acknowledge" (low level on SDA) is returned during the acknowledge cycle. FTE: SMBus Free Timer Enable Bit. 0: No timeout when SCL is high. 1: Timeout when SCL high time exceeds limit specified by the SMB0CR value. TOE: SMBus Timeout Enable Bit. 0: No timeout when SCL is low. 1: Timeout when SCL low time exceeds limit specified by Timer 4, if enabled. Rev. 1.3 243 C8051F060/1/2/3/4/5/6/7 20.4.2. Clock Rate Register Figure 20.9. SMB0CR: SMBus0 Clock Rate Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0xCF SFR Page: 0 SMB0CR.[7:0]: SMBus0 Clock Rate Preset. The SMB0CR Clock Rate register controls the frequency of the serial clock SCL in master mode. The 8-bit word stored in the SMB0CR Register preloads a dedicated 8-bit timer. The timer counts up, and when it rolls over to 0x00, the SCL logic state toggles. The SMB0CR setting should be bounded by the following equation , where SMB0CR is the unsigned 8-bit value in register SMB0CR, and SYSCLK is the system clock frequency in Hz: 6 SMB0C R    288 – 0.85  SYSCLK    1.125  10   The resulting SCL signal high and low times are given by the following equations: T LOW =  256 – SMB0CR   SYSCLK T HIGH   258 – SMB0CR   SYSCLK + 625ns Using the same value of SMB0CR from above, the Bus Free Timeout period is given in the following equation:  256 – SMB0CR  + 1T BFT  10  ---------------------------------------------------SYSCLK 244 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 20.4.3. Data Register The SMBus0 Data register SMB0DAT holds a byte of serial data to be transmitted or one that has just been received. Software can read or write to this register while the SI flag is set to logic 1; software should not attempt to access the SMB0DAT register when the SMBus is enabled and the SI flag reads logic 0 since the hardware may be in the process of shifting a byte of data in or out of the register. Data in SMB0DAT is always shifted out MSB first. After a byte has been received, the first bit of received data is located at the MSB of SMB0DAT. While data is being shifted out, data on the bus is simultaneously being shifted in. Therefore, SMB0DAT always contains the last data byte present on the bus. In the event of lost arbitration, the transition from master transmitter to slave receiver is made with the correct data in SMB0DAT. Figure 20.10. SMB0DAT: SMBus0 Data Register R/W R/W R/W R/W R/W R/W R/W Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 R/W Reset Value 00000000 Bits7-0: Bit0 SFR Address: 0xC2 SFR Page: 0 SMB0DAT: SMBus0 Data. The SMB0DAT register contains a byte of data to be transmitted on the SMBus0 serial interface or a byte that has just been received on the SMBus0 serial interface. The CPU can read from or write to this register whenever the SI serial interrupt flag (SMB0CN.3) is set to logic 1. When the SI flag is not set, the system may be in the process of shifting data and the CPU should not attempt to access this register. 20.4.4. Address Register The SMB0ADR Address register holds the slave address for the SMBus0 interface. In slave mode, the seven most-significant bits hold the 7-bit slave address. The least significant bit (Bit0) is used to enable the recognition of the general call address (0x00). If Bit0 is set to logic 1, the general call address will be recognized. Otherwise, the general call address is ignored. The contents of this register are ignored when Rev. 1.3 245 C8051F060/1/2/3/4/5/6/7 SMBus0 is operating in master mode. Figure 20.11. SMB0ADR: SMBus0 Address Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value SLV6 SLV5 SLV4 SLV3 SLV2 SLV1 SLV0 GC 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 SFR Address: 0xC3 SFR Page: 0 Bits7-1: SLV6-SLV0: SMBus0 Slave Address. These bits are loaded with the 7-bit slave address to which SMBus0 will respond when operating as a slave transmitter or slave receiver. SLV6 is the most significant bit of the address and corresponds to the first bit of the address byte received. Bit0: GC: General Call Address Enable. This bit is used to enable general call address (0x00) recognition. 0: General call address is ignored. 1: General call address is recognized. 20.4.5. Status Register The SMB0STA Status register holds an 8-bit status code indicating the current state of the SMBus0 interface. There are 28 possible SMBus0 states, each with a corresponding unique status code. The five most significant bits of the status code vary while the three least-significant bits of a valid status code are fixed at zero when SI = ‘1’. Therefore, all possible status codes are multiples of eight. This facilitates the use of status codes in software as an index used to branch to appropriate service routines (allowing 8 bytes of code to service the state or jump to a more extensive service routine). For the purposes of user software, the contents of the SMB0STA register is only defined when the SI flag is logic 1. Software should never write to the SMB0STA register; doing so will yield indeterminate results. 246 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 The 28 SMBus0 states, along with their corresponding status codes, are given in Table 1.1. Figure 20.12. SMB0STA: SMBus0 Status Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value STA7 STA6 STA5 STA4 STA3 STA2 STA1 STA0 11111000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 SFR Address: 0xC1 SFR Page: 0 Bits7-3: STA7-STA3: SMBus0 Status Code. These bits contain the SMBus0 Status Code. There are 28 possible status codes; each status code corresponds to a single SMBus state. A valid status code is present in SMB0STA when the SI flag (SMB0CN.3) is set to logic 1. The content of SMB0STA is not defined when the SI flag is logic 0. Writing to the SMB0STA register at any time will yield indeterminate results. Bits2-0: STA2-STA0: The three least significant bits of SMB0STA are always read as logic 0 when the SI flag is logic 1. Rev. 1.3 247 C8051F060/1/2/3/4/5/6/7 Table 20.1. SMB0STA Status Codes and States Master Receiver Master Transmitter MT/ MR Mode 248 Status Code SMBus State Typical Action 0x08 START condition transmitted. Load SMB0DAT with Slave Address + R/W. Clear STA. 0x10 Repeated START condition transmitted. Load SMB0DAT with Slave Address + R/W. Clear STA. 0x18 Slave Address + W transmitted. ACK received. Load SMB0DAT with data to be transmitted. 0x20 Slave Address + W transmitted. NACK received. Acknowledge poll to retry. Set STO + STA. 0x28 Data byte transmitted. ACK received. 0x30 Data byte transmitted. NACK received. 1) Retry transfer OR 2) Set STO. 0x38 Arbitration Lost. Save current data. 0x40 Slave Address + R transmitted. ACK received. If only receiving one byte, clear AA (send NACK after received byte). Wait for received data. 0x48 Slave Address + R transmitted. NACK received. Acknowledge poll to retry. Set STO + STA. 0x50 Data byte received. ACK transmitted. Read SMB0DAT. Wait for next byte. If next byte is last byte, clear AA. 0x58 Data byte received. NACK transmitted. Set STO. Rev. 1.3 1) Load SMB0DAT with next byte, OR 2) Set STO, OR 3) Clear STO then set STA for repeated START. C8051F060/1/2/3/4/5/6/7 Table 20.1. SMB0STA Status Codes and States All Slave Slave Transmitter Slave Receiver Mode Status Code SMBus State Typical Action 0x60 Own slave address + W received. ACK transmitted. Wait for data. 0x68 Arbitration lost in sending SLA + R/W as master. Own address + W received. ACK transmitted. Save current data for retry when bus is free. Wait for data. 0x70 General call address received. ACK transmitted. Wait for data. 0x78 Arbitration lost in sending SLA + R/W as master. General call address received. ACK transmitted. Save current data for retry when bus is free. 0x80 Data byte received. ACK transmitted. Read SMB0DAT. Wait for next byte or STOP. 0x88 Data byte received. NACK transmitted. Set STO to reset SMBus. 0x90 Data byte received after general call address. ACK transmitted. Read SMB0DAT. Wait for next byte or STOP. 0x98 Data byte received after general call address. NACK transmitted. Set STO to reset SMBus. 0xA0 STOP or repeated START received. No action necessary. 0xA8 Own address + R received. ACK transmitted. Load SMB0DAT with data to transmit. 0xB0 Arbitration lost in transmitting SLA + R/W as master. Own address + R received. ACK transmitted. Save current data for retry when bus is free. Load SMB0DAT with data to transmit. 0xB8 Data byte transmitted. ACK received. Load SMB0DAT with data to transmit. 0xC0 Data byte transmitted. NACK received. Wait for STOP. 0xC8 Last data byte transmitted (AA=0). ACK received. Set STO to reset SMBus. 0xD0 SCL Clock High Timer per SMB0CR timed out Set STO to reset SMBus. 0x00 Bus Error (illegal START or STOP) Set STO to reset SMBus. 0xF8 Idle State does not set SI. Rev. 1.3 249 C8051F060/1/2/3/4/5/6/7 250 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 21. Enhanced Serial Peripheral Interface (SPI0) The Enhanced Serial Peripheral Interface (SPI0) provides access to a flexible, full-duplex synchronous serial bus. SPI0 can operate as a master or slave device in both 3-wire or 4-wire modes, and supports multiple masters and slaves on a single SPI bus. The slave-select (NSS) signal can be configured as an input to select SPI0 in slave mode, or to disable Master Mode operation in a multi-master environment, avoiding contention on the SPI bus when more than one master attempts simultaneous data transfers. NSS can also be configured as a chip-select output in master mode, or disabled for 3-wire operation. Additional general purpose port I/O pins can be used to select multiple slave devices in master mode. Figure 21.1. SPI Block Diagram Rev. 1.3 251 C8051F060/1/2/3/4/5/6/7 21.1. Signal Descriptions The four signals used by SPI0 (MOSI, MISO, SCK, NSS) are described below. 21.1.1. Master Out, Slave In (MOSI) The master-out, slave-in (MOSI) signal is an output from a master device and an input to slave devices. It is used to serially transfer data from the master to the slave. This signal is an output when SPI0 is operating as a master and an input when SPI0 is operating as a slave. Data is transferred most-significant bit first. When configured as a master, MOSI is driven by the MSB of the shift register in both 3- and 4-wire mode. 21.1.2. Master In, Slave Out (MISO) The master-in, slave-out (MISO) signal is an output from a slave device and an input to the master device. It is used to serially transfer data from the slave to the master. This signal is an input when SPI0 is operating as a master and an output when SPI0 is operating as a slave. Data is transferred most-significant bit first. The MISO pin is placed in a high-impedance state when the SPI module is disabled and when the SPI operates in 4-wire mode as a slave that is not selected. When acting as a slave in 3-wire mode, MISO is always driven by the MSB of the shift register. 21.1.3. Serial Clock (SCK) The serial clock (SCK) signal is an output from the master device and an input to slave devices. It is used to synchronize the transfer of data between the master and slave on the MOSI and MISO lines. SPI0 generates this signal when operating as a master. The SCK signal is ignored by a SPI slave when the slave is not selected (NSS = 1) in 4-wire slave mode. 21.1.4. Slave Select (NSS) The function of the slave-select (NSS) signal is dependent on the setting of the NSSMD1 and NSSMD0 bits in the SPI0CN register. There are three possible modes that can be selected with these bits: 1. NSSMD[1:0] = 00: 3-Wire Master or 3-Wire Slave Mode: SPI0 operates in 3-wire mode, and NSS is disabled. When operating as a slave device, SPI0 is always selected in 3-wire mode. Since no select signal is present, SPI0 must be the only slave on the bus in 3-wire mode. This is intended for point-to-point communication between a master and one slave. 2. NSSMD[1:0] = 01: 4-Wire Slave or Multi-Master Mode: SPI0 operates in 4-wire mode, and NSS is enabled as an input. When operating as a slave, NSS selects the SPI0 device. When operating as a master, a 1-to-0 transition of the NSS signal disables the master function of SPI0 so that multiple master devices can be used on the same SPI bus. 3. NSSMD[1:0] = 1x: 4-Wire Master Mode: SPI0 operates in 4-wire mode, and NSS is enabled as an output. The setting of NSSMD0 determines what logic level the NSS pin will output. This configuration should only be used when operating SPI0 as a master device. See Figure 21.2, Figure 21.3, and Figure 21.4 for typical connection diagrams of the various operational modes. Note that the setting of NSSMD bits affects the pinout of the device. When in 3-wire master or 3-wire slave mode, the NSS pin will not be mapped by the crossbar. In all other modes, the NSS signal will be mapped to a pin on the device. See Section “18. Port Input/Output” on page 203 for general purpose port I/O and crossbar information. 252 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 21.2. SPI0 Master Mode Operation A SPI master device initiates all data transfers on a SPI bus. SPI0 is placed in master mode by setting the Master Enable flag (MSTEN, SPI0CN.6). Writing a byte of data to the SPI0 data register (SPI0DAT) when in master mode writes to the transmit buffer. If the SPI shift register is empty, the byte in the transmit buffer is moved to the shift register, and a data transfer begins. The SPI0 master immediately shifts out the data serially on the MOSI line while providing the serial clock on SCK. The SPIF (SPI0CN.7) flag is set to logic 1 at the end of the transfer. If interrupts are enabled, an interrupt request is generated when the SPIF flag is set. While the SPI0 master transfers data to a slave on the MOSI line, the addressed SPI slave device simultaneously transfers the contents of its shift register to the SPI master on the MISO line in a full-duplex operation. Therefore, the SPIF flag serves as both a transmit-complete and receive-data-ready flag. The data byte received from the slave is transferred MSB-first into the master's shift register. When a byte is fully shifted into the register, it is moved to the receive buffer where it can be read by the processor by reading SPI0DAT. When configured as a master, SPI0 can operate in one of three different modes: multi-master mode, 3-wire single-master mode, and 4-wire single-master mode. The default, multi-master mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 1. In this mode, NSS is an input to the device, and is used to disable the master SPI0 when another master is accessing the bus. When NSS is pulled low in this mode, MSTEN (SPI0CN.6) and SPIEN (SPI0CN.0) are set to 0 to disable the SPI master device, and a Mode Fault is generated (MODF, SPI0CN.5 = 1). Mode Fault will generate an interrupt if enabled. SPI0 must be manually re-enabled in software under these circumstances. In multi-master systems, devices will typically default to being slave devices while they are not acting as the system master device. In multi-master mode, slave devices can be addressed individually (if needed) using general-purpose I/O pins. Figure 21.2 shows a connection diagram between two master devices in multiple-master mode. 3-wire single-master mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 0. In this mode, NSS is not used, and is not mapped to an external port pin through the crossbar. Any slave devices that must be addressed in this mode should be selected using general-purpose I/O pins. Figure 21.3 shows a connection diagram between a master device in 3-wire master mode and a slave device. 4-wire single-master mode is active when NSSMD1 (SPI0CN.3) = 1. In this mode, NSS is configured as an output pin, and can be used as a slave-select signal for a single SPI device. In this mode, the output value of NSS is controlled (in software) with the bit NSSMD0 (SPI0CN.2). Additional slave devices can be addressed using general-purpose I/O pins. Figure 21.4 shows a connection diagram for a master device in 4-wire master mode and two slave devices. Rev. 1.3 253 C8051F060/1/2/3/4/5/6/7 Figure 21.2. Multiple-Master Mode Connection Diagram Figure 21.3. 3-Wire Single Master and 3-Wire Single Slave Mode Connection Diagram Figure 21.4. 4-Wire Single Master Mode and 4-Wire Slave Mode Connection Diagram 254 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 21.3. SPI0 Slave Mode Operation When SPI0 is enabled and not configured as a master, it will operate as a SPI slave. As a slave, bytes are shifted in through the MOSI pin and out through the MISO pin by a master device controlling the SCK signal. A bit counter in the SPI0 logic counts SCK edges. When 8 bits have been shifted through the shift register, the SPIF flag is set to logic 1, and the byte is copied into the receive buffer. Data is read from the receive buffer by reading SPI0DAT. A slave device cannot initiate transfers. Data to be transferred to the master device is pre-loaded into the shift register by writing to SPI0DAT. Writes to SPI0DAT are doublebuffered, and are placed in the transmit buffer first. If the shift register is empty, the contents of the transmit buffer will immediately be transferred into the shift register. When the shift register already contains data, the SPI will load the shift register with the transmit buffer’s contents after the last SCK edge of the next (or current) SPI transfer. When configured as a slave, SPI0 can be configured for 4-wire or 3-wire operation. The default, 4-wire slave mode, is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 1. In 4-wire mode, the NSS signal is routed to a port pin and configured as a digital input. SPI0 is enabled when NSS is logic 0, and disabled when NSS is logic 1. The bit counter is reset on a falling edge of NSS. Note that the NSS signal must be driven low at least 2 system clocks before the first active edge of SCK for each byte transfer. Figure 21.4 shows a connection diagram between two slave devices in 4-wire slave mode and a master device. 3-wire slave mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 0. NSS is not used in this mode, and is not mapped to an external port pin through the crossbar. Since there is no way of uniquely addressing the device in 3-wire slave mode, SPI0 must be the only slave device present on the bus. It is important to note that in 3-wire slave mode there is no external means of resetting the bit counter that determines when a full byte has been received. The bit counter can only be reset by disabling and reenabling SPI0 with the SPIEN bit. Figure 21.3 shows a connection diagram between a slave device in 3wire slave mode and a master device. 21.4. SPI0 Interrupt Sources When SPI0 interrupts are enabled, the following four flags will generate an interrupt when they are set to logic 1: Note that all of the following bits must be cleared by software. 1. The SPI Interrupt Flag, SPIF (SPI0CN.7) is set to logic 1 at the end of each byte transfer. This flag can occur in all SPI0 modes. 2. The Write Collision Flag, WCOL (SPI0CN.6) is set to logic 1 if a write to SPI0DAT is attempted when the transmit buffer has not been emptied to the SPI shift register. When this occurs, the write to SPI0DAT will be ignored, and the transmit buffer will not be written.This flag can occur in all SPI0 modes. 3. The Mode Fault Flag MODF (SPI0CN.5) is set to logic 1 when SPI0 is configured as a master, and for multi-master mode and the NSS pin is pulled low. When a Mode Fault occurs, the MSTEN and SPIEN bits in SPI0CN are set to logic 0 to disable SPI0 and allow another master device to access the bus. 4. The Receive Overrun Flag RXOVRN (SPI0CN.4) is set to logic 1 when configured as a slave, and a transfer is completed and the receive buffer still holds an unread byte from a previous transfer. The new byte is not transferred to the receive buffer, allowing the previously received data byte to be read. The data byte which caused the overrun is lost. Rev. 1.3 255 C8051F060/1/2/3/4/5/6/7 21.5. Serial Clock Timing Four combinations of serial clock phase and polarity can be selected using the clock control bits in the SPI0 Configuration Register (SPI0CFG). The CKPHA bit (SPI0CFG.5) selects one of two clock phases (edge used to latch the data). The CKPOL bit (SPI0CFG.4) selects between an active-high or active-low clock. Both master and slave devices must be configured to use the same clock phase and polarity. SPI0 should be disabled (by clearing the SPIEN bit, SPI0CN.0) when changing the clock phase or polarity. The clock and data line relationships for master mode are shown in Figure 21.5. For slave mode, the clock and data relationships are shown in Figure 21.6 and Figure 21.7. Note that CKPHA must be set to ‘0’ on both the master and slave SPI when communicating between two of the following devices: C8051F04x, C8051F06x, C8051F12x, C8051F31x, C8051F32x, and C8051F33x The SPI0 Clock Rate Register (SPI0CKR) as shown in Figure 21.10 controls the master mode serial clock frequency. This register is ignored when operating in slave mode. When the SPI is configured as a master, the maximum data transfer rate (bits/sec) is one-half the system clock frequency or 12.5 MHz, whichever is slower. When the SPI is configured as a slave, the maximum data transfer rate (bits/sec) for full-duplex operation is 1/10 the system clock frequency, provided that the master issues SCK, NSS (in 4-wire slave mode), and the serial input data synchronously with the slave’s system clock. If the master issues SCK, NSS, and the serial input data asynchronously, the maximum data transfer rate (bits/sec) must be less than 1/10 the system clock frequency. In the special case where the master only wants to transmit data to the slave and does not need to receive data from the slave (i.e. half-duplex operation), the SPI slave can receive data at a maximum data transfer rate (bits/sec) of 1/4 the system clock frequency. This is provided that the master issues SCK, NSS, and the serial input data synchronously with the slave’s system clock. Figure 21.5. Master Mode Data/Clock Timing 256 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 21.6. Slave Mode Data/Clock Timing (CKPHA = 0) Figure 21.7. Slave Mode Data/Clock Timing (CKPHA = 1) Rev. 1.3 257 C8051F060/1/2/3/4/5/6/7 21.6. SPI Special Function Registers SPI0 is accessed and controlled through four special function registers in the system controller: SPI0CN Control Register, SPI0DAT Data Register, SPI0CFG Configuration Register, and SPI0CKR Clock Rate Register. The four special function registers related to the operation of the SPI0 Bus are described in the following figures. Figure 21.8. SPI0CFG: SPI0 Configuration Register R R/W R/W R/W R R R R Reset Value SPIBSY MSTEN CKPHA CKPOL SLVSEL NSSIN SRMT RXBMT 00000111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit 7: Bit 6: Bit 5: Bit 4: Bit 3: Bit 2: Bit 1: Bit 0: Bit0 SFR Address: 0x9A SFR Page: 0 SPIBSY: SPI Busy (read only). This bit is set to logic 1 when a SPI transfer is in progress (Master or slave Mode). MSTEN: Master Mode Enable. 0: Disable master mode. Operate in slave mode. 1: Enable master mode. Operate as a master. CKPHA: SPI0 Clock Phase. This bit controls the SPI0 clock phase. 0: Data centered on first edge of SCK period.† 1: Data centered on second edge of SCK period.† CKPOL: SPI0 Clock Polarity. This bit controls the SPI0 clock polarity. 0: SCK line low in idle state. 1: SCK line high in idle state. SLVSEL: Slave Selected Flag (read only). This bit is set to logic 1 whenever the NSS pin is low indicating SPI0 is the selected slave. It is cleared to logic 0 when NSS is high (slave not selected). This bit does not indicate the instantaneous value at the NSS pin, but rather a de-glitched version of the pin input. NSSIN: NSS Instantaneous Pin Input (read only). This bit mimics the instantaneous value that is present on the NSS port pin at the time that the register is read. This input is not de-glitched. SRMT: Shift Register Empty (Valid in Slave Mode, read only). This bit will be set to logic 1 when all data has been transferred in/out of the shift register, and there is no new information available to read from the transmit buffer or write to the receive buffer. It returns to logic 0 when a data byte is transferred to the shift register from the transmit buffer or by a transition on SCK. NOTE: SRMT = 1 when in Master Mode. RXBMT: Receive Buffer Empty (Valid in Slave Mode, read only). This bit will be set to logic 1 when the receive buffer has been read and contains no new information. If there is new information available in the receive buffer that has not been read, this bit will return to logic 0. NOTE: RXBMT = 1 when in Master Mode. †In slave mode, data on MOSI is sampled in the center of each data bit. In master mode, data on MISO is sampled one SYSCLK before the end of each data bit, to provide maximum settling time for the slave device. See Table 21.1 for timing parameters. 258 Rev. 1.3 C8051F060/1/2/3/4/5/6/7 Figure 21.9. SPI0CN: SPI0 Control Register R/W R/W R/W R/W R/W R/W R R/W Reset Value SPIF WCOL MODF RXOVRN NSSMD1 NSSMD0 TXBMT SPIEN 00000110 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit Addressable SFR Address: 0xF8 SFR Page: 0 Bit0 Bit 7: SPIF: SPI0 Interrupt Flag. This bit is set to logic 1 by hardware at the end of a data transfer. If interrupts are enabled, setting this bit causes the CPU to vector to the SPI0 interrupt service routine. This bit is not automatically cleared by hardware. It must be cleared by software. Bit 6: WCOL: Write Collision Flag. This bit is set to logic 1 by hardware (and generates a SPI0 interrupt) to indicate a write to the SPI0 data register was attempted while a data transfer was in progress. It must be cleared by software. Bit 5: MODF: Mode Fault Flag. This bit is set to logic 1 by hardware (and generates a SPI0 interrupt) when a master mode collision is detected (NSS is low, MSTEN = 1, and NSSMD[1:0] = 01). This bit is not automatically cleared by hardware. It must be cleared by software. Bit 4: RXOVRN: Receive Overrun Flag (Slave Mode only). This bit is set to logic 1 by hardware (and generates a SPI0 interrupt) when the receive buffer still holds unread data from a previous transfer and the last bit of the current transfer is shifted into the SPI0 shift register. This bit is not automatically cleared by hardware. It must be cleared by software. Bits 3-2: NSSMD1-NSSMD0: Slave Select Mode. Selects between the following NSS operation modes: (See Section “21.2. SPI0 Master Mode Operation” on page 253 and Section “21.3. SPI0 Slave Mode Operation” on page 255). 00: 3-Wire Slave or 3-wire Master Mode. NSS signal is not routed to a port pin. 01: 4-Wire Slave or Multi-Master Mode (Default). NSS is always an input to the device. 1x: 4-Wire Single-Master Mode. NSS signal is mapped as an output from the device and will assume the value of NSSMD0. Bit 1: TXBMT: Transmit Buffer Empty. This bit will be set to logic 0 when new data has been written to the transmit buffer. When data in the transmit buffer is transferred to the SPI shift register, this bit will be set to logic 1, indicating that it is safe to write a new byte to the transmit buffer. Bit 0: SPIEN: SPI0 Enable. This bit enables/disables the SPI. 0: SPI disabled. 1: SPI enabled. Rev. 1.3 259 C8051F060/1/2/3/4/5/6/7 Figure 21.10. SPI0CKR: SPI0 Clock Rate Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value SCR7 SCR6 SCR5 SCR4 SCR3 SCR2 SCR1 SCR0 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 SFR Address: 0x9D SFR Page: 0 Bits 7-0: SCR7-SCR0: SPI0 Clock Rate. These bits determine the frequency of the SCK output when the SPI0 module is configured for master mode operation. The SCK clock frequency is a divided version of the system clock, and is given in the following equation, where SYSCLK is the system clock frequency and SPI0CKR is the 8-bit value held in the SPI0CKR register. SYSCLK f SCK = ------------------------------------------------2   SPI 0CKR + 1  for 0