TEXAS INSTRUMENTS LM3S2139 Technical data

PRELIMINARY

LM3S2139 Microcontroller

DATA SHEET
Copyright © 2007 Luminary Micro, Inc.DS-LM3S2139-03
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Table of Contents

About This Document .................................................................................................................... 18
Audience .............................................................................................................................................. 18
About This Manual ................................................................................................................................ 18
Related Documents ............................................................................................................................... 18
Documentation Conventions .................................................................................................................. 18
1 Overview ............................................................................................................................. 20
1.1 Product Features ...................................................................................................................... 20
1.2 Target Applications .................................................................................................................... 25
1.3 High-Level Block Diagram ......................................................................................................... 25
1.4 Functional Overview .................................................................................................................. 26
1.4.1 ARM Cortex™-M3 ..................................................................................................................... 27
1.4.2 Motor Control Peripherals .......................................................................................................... 27
1.4.3 Serial Communications Peripherals ............................................................................................ 28
1.4.4 System Peripherals ................................................................................................................... 29
1.4.5 Memory Peripherals .................................................................................................................. 30
1.4.6 Additional Features ................................................................................................................... 30
1.4.7 Hardware Details ...................................................................................................................... 31
2 Cortex-M3 Core .................................................................................................................. 32
2.1 Block Diagram .......................................................................................................................... 33
2.2 Functional Description ............................................................................................................... 33
2.2.1 Serial Wire and JTAG Debug ..................................................................................................... 33
2.2.2 Embedded Trace Macrocell (ETM) ............................................................................................. 34
2.2.3 Trace Port Interface Unit (TPIU) ................................................................................................. 34
2.2.4 ROM Table ............................................................................................................................... 34
2.2.5 Memory Protection Unit (MPU) ................................................................................................... 34
2.2.6 Nested Vectored Interrupt Controller (NVIC) ................................................................................ 34
3 Memory Map ....................................................................................................................... 38
4 Interrupts ............................................................................................................................ 40
5 JTAG .................................................................................................................................... 42
5.1 Block Diagram .......................................................................................................................... 43
5.2 Functional Description ............................................................................................................... 43
5.2.1 JTAG Interface Pins .................................................................................................................. 44
5.2.2 JTAG TAP Controller ................................................................................................................. 45
5.2.3 Shift Registers .......................................................................................................................... 46
5.2.4 Operational Considerations ........................................................................................................ 46
5.3 Initialization and Configuration ................................................................................................... 49
5.4 Register Descriptions ................................................................................................................ 49
5.4.1 Instruction Register (IR) ............................................................................................................. 49
5.4.2 Data Registers .......................................................................................................................... 51
6 System Control ................................................................................................................... 53
6.1 Functional Description ............................................................................................................... 53
6.1.1 Device Identification .................................................................................................................. 53
6.1.2 Reset Control ............................................................................................................................ 53
6.1.3 Power Control ........................................................................................................................... 56
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6.1.4 Clock Control ............................................................................................................................ 56
6.1.5 System Control ......................................................................................................................... 58
6.2 Initialization and Configuration ................................................................................................... 58
6.3 Register Map ............................................................................................................................ 59
6.4 Register Descriptions ................................................................................................................ 60
7 Internal Memory ............................................................................................................... 109
7.1 Block Diagram ........................................................................................................................ 109
7.2 Functional Description ............................................................................................................. 109
7.2.1 SRAM Memory ........................................................................................................................ 109
7.2.2 Flash Memory ......................................................................................................................... 110
7.3 Flash Memory Initialization and Configuration ........................................................................... 111
7.3.1 Flash Programming ................................................................................................................. 111
7.3.2 Nonvolatile Register Programming ........................................................................................... 112
7.4 Register Map .......................................................................................................................... 112
7.5 Flash Control Offset ................................................................................................................. 113
7.6 System Control Offset .............................................................................................................. 120
8 GPIO .................................................................................................................................. 133
8.1 Function Description ................................................................................................................ 133
8.1.1 Data Control ........................................................................................................................... 133
8.1.2 Interrupt Control ...................................................................................................................... 134
8.1.3 Mode Control .......................................................................................................................... 135
8.1.4 Commit Control ....................................................................................................................... 135
8.1.5 Pad Control ............................................................................................................................. 135
8.1.6 Identification ........................................................................................................................... 136
8.2 Initialization and Configuration ................................................................................................. 136
8.3 Register Map .......................................................................................................................... 137
8.4 Register Descriptions .............................................................................................................. 139
9 Timers ............................................................................................................................... 174
9.1 Block Diagram ........................................................................................................................ 175
9.2 Functional Description ............................................................................................................. 175
9.2.1 GPTM Reset Conditions .......................................................................................................... 175
9.2.2 32-Bit Timer Operating Modes .................................................................................................. 175
9.2.3 16-Bit Timer Operating Modes .................................................................................................. 177
9.3 Initialization and Configuration ................................................................................................. 181
9.3.1 32-Bit One-Shot/Periodic Timer Mode ....................................................................................... 181
9.3.2 32-Bit Real-Time Clock (RTC) Mode ......................................................................................... 182
9.3.3 16-Bit One-Shot/Periodic Timer Mode ....................................................................................... 182
9.3.4 16-Bit Input Edge Count Mode ................................................................................................. 183
9.3.5 16-Bit Input Edge Timing Mode ................................................................................................ 183
9.3.6 16-Bit PWM Mode ................................................................................................................... 184
9.4 Register Map .......................................................................................................................... 184
9.5 Register Descriptions .............................................................................................................. 185
10 Watchdog Timer ............................................................................................................... 207
10.1 Block Diagram ........................................................................................................................ 207
10.2 Functional Description ............................................................................................................. 207
10.3 Initialization and Configuration ................................................................................................. 208
10.4 Register Map .......................................................................................................................... 208
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10.5 Register Descriptions .............................................................................................................. 209
11 ADC ................................................................................................................................... 230
11.1 Block Diagram ........................................................................................................................ 231
11.2 Functional Description ............................................................................................................. 231
11.2.1 Sample Sequencers ................................................................................................................ 231
11.2.2 Module Control ........................................................................................................................ 232
11.2.3 Hardware Sample Averaging Circuit ......................................................................................... 233
11.2.4 Analog-to-Digital Converter ...................................................................................................... 233
11.2.5 Test Modes ............................................................................................................................. 233
11.2.6 Internal Temperature Sensor .................................................................................................... 233
11.3 Initialization and Configuration ................................................................................................. 234
11.3.1 Module Initialization ................................................................................................................. 234
11.3.2 Sample Sequencer Configuration ............................................................................................. 234
11.4 Register Map .......................................................................................................................... 235
11.5 Register Descriptions .............................................................................................................. 236
12 UART ................................................................................................................................. 267
12.1 Block Diagram ........................................................................................................................ 268
12.2 Functional Description ............................................................................................................. 268
12.2.1 Transmit/Receive Logic ........................................................................................................... 268
12.2.2 Baud-Rate Generation ............................................................................................................. 269
12.2.3 Data Transmission .................................................................................................................. 270
12.2.4 Serial IR (SIR) ......................................................................................................................... 270
12.2.5 FIFO Operation ....................................................................................................................... 271
12.2.6 Interrupts ................................................................................................................................ 271
12.2.7 Loopback Operation ................................................................................................................ 272
12.2.8 IrDA SIR block ........................................................................................................................ 272
12.3 Initialization and Configuration ................................................................................................. 272
12.4 Register Map .......................................................................................................................... 273
12.5 Register Descriptions .............................................................................................................. 274
13 SSI ..................................................................................................................................... 307
13.1 Block Diagram ........................................................................................................................ 307
13.2 Functional Description ............................................................................................................. 307
13.2.1 Bit Rate Generation ................................................................................................................. 308
13.2.2 FIFO Operation ....................................................................................................................... 308
13.2.3 Interrupts ................................................................................................................................ 308
13.2.4 Frame Formats ....................................................................................................................... 309
13.3 Initialization and Configuration ................................................................................................. 316
13.4 Register Map .......................................................................................................................... 317
13.5 Register Descriptions .............................................................................................................. 318
14 Inter-Integrated Circuit (I2C) Interface ............................................................................ 341
14.1 Block Diagram ........................................................................................................................ 341
14.2 Functional Description ............................................................................................................. 341
14.2.1 I2C Bus Functional Overview .................................................................................................... 342
14.2.2 Available Speed Modes ........................................................................................................... 344
14.2.3 Interrupts ................................................................................................................................ 345
14.2.4 Loopback Operation ................................................................................................................ 345
14.2.5 Command Sequence Flow Charts ............................................................................................ 345
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14.3 Initialization and Configuration ................................................................................................. 352
14.4 I2C Register Map ..................................................................................................................... 353
14.5 I2C Master .............................................................................................................................. 354
14.6 I2C Slave ................................................................................................................................ 367
15 CAN ................................................................................................................................... 376
15.1 Controller Area Network Overview ............................................................................................ 376
15.2 Controller Area Network Features ............................................................................................ 376
15.3 Controller Area Network Block Diagram .................................................................................... 377
15.4 Controller Area Network Functional Description ......................................................................... 378
15.4.1 Initialization ............................................................................................................................. 378
15.4.2 Operation ............................................................................................................................... 379
15.4.3 Transmitting Message Objects ................................................................................................. 379
15.4.4 Configuring a Transmit Message Object .................................................................................... 379
15.4.5 Updating a Transmit Message Object ....................................................................................... 380
15.4.6 Accepting Received Message Objects ...................................................................................... 380
15.4.7 Receiving a Data Frame .......................................................................................................... 381
15.4.8 Receiving a Remote Frame ...................................................................................................... 381
15.4.9 Receive/Transmit Priority ......................................................................................................... 381
15.4.10 Configuring a Receive Message Object .................................................................................... 381
15.4.11 Handling of Received Message Objects .................................................................................... 382
15.4.12 Handling of Interrupts .............................................................................................................. 382
15.4.13 Bit Timing Configuration Error Considerations ........................................................................... 383
15.4.14 Bit Time and Bit Rate ............................................................................................................... 383
15.4.15 Calculating the Bit Timing Parameters ...................................................................................... 385
15.5 Controller Area Network Register Map ...................................................................................... 387
15.6 Register Descriptions .............................................................................................................. 389
16 Analog Comparators ....................................................................................................... 420
16.1 Block Diagram ........................................................................................................................ 421
16.2 Functional Description ............................................................................................................. 421
16.2.1 Internal Reference Programming .............................................................................................. 423
16.3 Initialization and Configuration ................................................................................................. 424
16.4 Register Map .......................................................................................................................... 424
16.5 Register Descriptions .............................................................................................................. 425
17 Pin Diagram ...................................................................................................................... 433
18 Signal Tables .................................................................................................................... 434
19 Operating Characteristics ............................................................................................... 447
20 Electrical Characteristics ................................................................................................ 448
20.1 DC Characteristics .................................................................................................................. 448
20.1.1 Maximum Ratings ................................................................................................................... 448
20.1.2 Recommended DC Operating Conditions .................................................................................. 448
20.1.3 On-Chip Low Drop-Out (LDO) Regulator Characteristics ............................................................ 449
20.1.4 Power Specifications ............................................................................................................... 449
20.1.5 Flash Memory Characteristics .................................................................................................. 450
20.2 AC Characteristics ................................................................................................................... 451
20.2.1 Load Conditions ...................................................................................................................... 451
20.2.2 Clocks .................................................................................................................................... 451
20.2.3 Temperature Sensor ................................................................................................................ 452
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20.2.4 Analog-to-Digital Converter ...................................................................................................... 452
20.2.5 Analog Comparator ................................................................................................................. 452
20.2.6 I2C ......................................................................................................................................... 453
20.2.7 Synchronous Serial Interface (SSI) ........................................................................................... 453
20.2.8 JTAG and Boundary Scan ........................................................................................................ 455
20.2.9 General-Purpose I/O ............................................................................................................... 456
20.2.10 Reset ..................................................................................................................................... 457
21 Package Information ........................................................................................................ 459
A Serial Flash Loader .......................................................................................................... 461
A.1 Serial Flash Loader ................................................................................................................. 461
A.2 Interfaces ............................................................................................................................... 461
A.2.1 UART ..................................................................................................................................... 461
A.2.2 SSI ......................................................................................................................................... 461
A.3 Packet Handling ...................................................................................................................... 462
A.3.1 Packet Format ........................................................................................................................ 462
A.3.2 Sending Packets ..................................................................................................................... 462
A.3.3 Receiving Packets ................................................................................................................... 462
A.4 Commands ............................................................................................................................. 463
A.4.1 COMMAND_PING (0X20) ........................................................................................................ 463
A.4.2 COMMAND_GET_STATUS (0x23) ........................................................................................... 463
A.4.3 COMMAND_DOWNLOAD (0x21) ............................................................................................. 463
A.4.4 COMMAND_SEND_DATA (0x24) ............................................................................................. 464
A.4.5 COMMAND_RUN (0x22) ......................................................................................................... 464
A.4.6 COMMAND_RESET (0x25) ..................................................................................................... 464
B Ordering Information ....................................................................................................... 466
B.1 Ordering Information ................................................................................................................ 466
B.2 Company Information .............................................................................................................. 466
B.3 Support Information ................................................................................................................. 466
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List of Figures

Figure 1-1. Stellaris® Fury-class High-Level Block Diagram ................................................................ 26
Figure 2-1. CPU Block Diagram ......................................................................................................... 33
Figure 2-2. TPIU Block Diagram ........................................................................................................ 34
Figure 5-1. JTAG Module Block Diagram ............................................................................................ 43
Figure 5-2. Test Access Port State Machine ....................................................................................... 46
Figure 5-3. IDCODE Register Format ................................................................................................. 51
Figure 5-4. BYPASS Register Format ................................................................................................ 52
Figure 5-5. Boundary Scan Register Format ....................................................................................... 52
Figure 6-1. External Circuitry to Extend Reset .................................................................................... 54
Figure 7-1. Flash Block Diagram ...................................................................................................... 109
Figure 8-1. GPIODATA Write Example ............................................................................................. 134
Figure 8-2. GPIODATA Read Example ............................................................................................. 134
Figure 9-1. GPTM Module Block Diagram ........................................................................................ 175
Figure 9-2. 16-Bit Input Edge Count Mode Example .......................................................................... 179
Figure 9-3. 16-Bit Input Edge Time Mode Example ........................................................................... 180
Figure 9-4. 16-Bit PWM Mode Example ............................................................................................ 181
Figure 10-1. WDT Module Block Diagram .......................................................................................... 207
Figure 11-1. ADC Module Block Diagram ........................................................................................... 231
Figure 11-2. Internal Temperature Sensor Characteristic ..................................................................... 234
Figure 12-1. UART Module Block Diagram ......................................................................................... 268
Figure 12-2. UART Character Frame ................................................................................................. 269
Figure 12-3. IrDA Data Modulation ..................................................................................................... 271
Figure 13-1. SSI Module Block Diagram ............................................................................................. 307
Figure 13-2. TI Synchronous Serial Frame Format (Single Transfer) .................................................... 310
Figure 13-3. TI Synchronous Serial Frame Format (Continuous Transfer) ............................................ 310
Figure 13-4. Freescale SPI Format (Single Transfer) with SPO=0 and SPH=0 ...................................... 311
Figure 13-5. Freescale SPI Format (Continuous Transfer) with SPO=0 and SPH=0 .............................. 311
Figure 13-6. Freescale SPI Frame Format with SPO=0 and SPH=1 ..................................................... 312
Figure 13-7. Freescale SPI Frame Format (Single Transfer) with SPO=1 and SPH=0 ........................... 313
Figure 13-8. Freescale SPI Frame Format (Continuous Transfer) with SPO=1 and SPH=0 .................... 313
Figure 13-9. Freescale SPI Frame Format with SPO=1 and SPH=1 ..................................................... 314
Figure 13-10. MICROWIRE Frame Format (Single Frame) .................................................................... 315
Figure 13-11. MICROWIRE Frame Format (Continuous Transfer) ......................................................... 316
Figure 13-12. MICROWIRE Frame Format, SSIFss Input Setup and Hold Requirements ........................ 316
Figure 14-1. I2C Block Diagram ......................................................................................................... 341
Figure 14-2. I2C Bus Configuration .................................................................................................... 342
Figure 14-3. START and STOP Conditions ......................................................................................... 342
Figure 14-4. Complete Data Transfer with a 7-Bit Address ................................................................... 343
Figure 14-5. R/S Bit in First Byte ........................................................................................................ 343
Figure 14-6. Data Validity During Bit Transfer on the I2C Bus ............................................................... 343
Figure 14-7. Master Single SEND ...................................................................................................... 346
Figure 14-8. Master Single RECEIVE ................................................................................................. 347
Figure 14-9. Master Burst SEND ....................................................................................................... 348
Figure 14-10. Master Burst RECEIVE .................................................................................................. 349
Figure 14-11. Master Burst RECEIVE after Burst SEND ........................................................................ 350
Figure 14-12. Master Burst SEND after Burst RECEIVE ........................................................................ 351
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Figure 14-13. Slave Command Sequence ............................................................................................ 352
Figure 15-1. CAN Module Block Diagram ........................................................................................... 377
Figure 15-2. CAN Bit Time ................................................................................................................ 384
Figure 16-1. Analog Comparator Module Block Diagram ..................................................................... 421
Figure 16-2. Structure of Comparator Unit .......................................................................................... 422
Figure 16-3. Comparator Internal Reference Structure ........................................................................ 423
Figure 17-1. Pin Connection Diagram ................................................................................................ 433
Figure 20-1. Load Conditions ............................................................................................................ 451
Figure 20-2. I2C Timing ..................................................................................................................... 453
Figure 20-3. SSI Timing for TI Frame Format (FRF=01), Single Transfer Timing Measurement .............. 454
Figure 20-4. SSI Timing for MICROWIRE Frame Format (FRF=10), Single Transfer ............................. 454
Figure 20-5. SSI Timing for SPI Frame Format (FRF=00), with SPH=1 ................................................. 455
Figure 20-6. JTAG Test Clock Input Timing ......................................................................................... 456
Figure 20-7. JTAG Test Access Port (TAP) Timing .............................................................................. 456
Figure 20-8. JTAG TRST Timing ........................................................................................................ 456
Figure 20-9. External Reset Timing (RST) .......................................................................................... 457
Figure 20-10. Power-On Reset Timing ................................................................................................. 458
Figure 20-11. Brown-Out Reset Timing ................................................................................................ 458
Figure 20-12. Software Reset Timing ................................................................................................... 458
Figure 20-13. Watchdog Reset Timing ................................................................................................. 458
Figure 21-1. 100-Pin LQFP Package .................................................................................................. 459
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List of Tables

Table 1. Documentation Conventions ............................................................................................ 18
Table 3-1. Memory Map ................................................................................................................... 38
Table 4-1. Exception Types .............................................................................................................. 40
Table 4-2. Interrupts ........................................................................................................................ 41
Table 5-1. JTAG Port Pins Reset State ............................................................................................. 44
Table 5-2. JTAG Instruction Register Commands ............................................................................... 49
Table 6-1. System Control Register Map ........................................................................................... 59
Table 6-2. VADJ to VOUT ................................................................................................................ 64
Table 6-3. Default Crystal Field Values and PLL Programming ........................................................... 71
Table 7-1. Flash Protection Policy Combinations ............................................................................. 111
Table 7-2. Flash Resident Registers ............................................................................................... 112
Table 7-3. Internal Memory Register Map ........................................................................................ 112
Table 8-1. GPIO Pad Configuration Examples ................................................................................. 136
Table 8-2. GPIO Interrupt Configuration Example ............................................................................ 136
Table 8-3. GPIO Register Map ....................................................................................................... 138
Table 9-1. 16-Bit Timer With Prescaler Configurations ..................................................................... 178
Table 9-2. Timers Register Map ...................................................................................................... 184
Table 10-1. Watchdog Timer Register Map ........................................................................................ 208
Table 11-1. Samples and FIFO Depth of Sequencers ........................................................................ 231
Table 11-2. ADC Register Map ......................................................................................................... 235
Table 12-1. UART Register Map ....................................................................................................... 273
Table 13-1. SSI Register Map .......................................................................................................... 317
Table 14-1. Examples of I2C Master Timer Period versus Speed Mode ............................................... 344
Table 14-2. Inter-Integrated Circuit (I2C) Interface Register Map ......................................................... 353
Table 14-3. Write Field Decoding for I2CMCS[3:0] Field (Sheet 1 of 3) ................................................ 358
Table 15-1. Transmit Message Object Bit Settings ............................................................................. 380
Table 15-2. Receive Message Object Bit Settings .............................................................................. 382
Table 15-3. CAN Protocol Ranges .................................................................................................... 384
Table 15-4. CAN Register Map ......................................................................................................... 387
Table 16-1. Comparator 0 Operating Modes ...................................................................................... 422
Table 16-2. Comparator 1 Operating Modes ..................................................................................... 422
Table 16-3. Comparator 2 Operating Modes ...................................................................................... 423
Table 16-4. Internal Reference Voltage and ACREFCTL Field Values ................................................. 423
Table 16-5. Analog Comparators Register Map ................................................................................. 425
Table 18-1. Signals by Pin Number ................................................................................................... 434
Table 18-2. Signals by Signal Name ................................................................................................. 438
Table 18-3. Signals by Function, Except for GPIO ............................................................................. 442
Table 18-4. GPIO Pins and Alternate Functions ................................................................................. 444
Table 19-1. Temperature Characteristics ........................................................................................... 447
Table 19-2. Thermal Characteristics ................................................................................................. 447
Table 20-1. Maximum Ratings .......................................................................................................... 448
Table 20-2. Recommended DC Operating Conditions ........................................................................ 448
Table 20-3. LDO Regulator Characteristics ....................................................................................... 449
Table 20-4. Detailed Power Specifications ........................................................................................ 450
Table 20-5. Flash Memory Characteristics ........................................................................................ 450
Table 20-6. Phase Locked Loop (PLL) Characteristics ....................................................................... 451
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Table 20-7. Clock Characteristics ..................................................................................................... 451
Table 20-8. Crystal Characteristics ................................................................................................... 451
Table 20-9. Temperature Sensor Characteristics ............................................................................... 452
Table 20-10. ADC Characteristics ....................................................................................................... 452
Table 20-11. Analog Comparator Characteristics ................................................................................. 452
Table 20-12. Analog Comparator Voltage Reference Characteristics .................................................... 453
Table 20-13. I2C Characteristics ......................................................................................................... 453
Table 20-14. SSI Characteristics ........................................................................................................ 453
Table 20-15. JTAG Characteristics ..................................................................................................... 455
Table 20-16. GPIO Characteristics ..................................................................................................... 457
Table 20-17. Reset Characteristics ..................................................................................................... 457
Table B-1. Part Ordering Information ............................................................................................... 466
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List of Registers

System Control .............................................................................................................................. 53
Register 1: Device Identification 0 (DID0), offset 0x000 ....................................................................... 61
Register 2: Brown-Out Reset Control (PBORCTL), offset 0x030 .......................................................... 63
Register 3: LDO Power Control (LDOPCTL), offset 0x034 ................................................................... 64
Register 4: Raw Interrupt Status (RIS), offset 0x050 ........................................................................... 65
Register 5: Interrupt Mask Control (IMC), offset 0x054 ........................................................................ 66
Register 6: Masked Interrupt Status and Clear (MISC), offset 0x058 .................................................... 67
Register 7: Reset Cause (RESC), offset 0x05C .................................................................................. 68
Register 8: Run-Mode Clock Configuration (RCC), offset 0x060 .......................................................... 69
Register 9: XTAL to PLL Translation (PLLCFG), offset 0x064 .............................................................. 73
Register 10: Run-Mode Clock Configuration 2 (RCC2), offset 0x070 ...................................................... 74
Register 11: Deep Sleep Clock Configuration (DSLPCLKCFG), offset 0x144 .......................................... 76
Register 12: Device Identification 1 (DID1), offset 0x004 ....................................................................... 77
Register 13: Device Capabilities 0 (DC0), offset 0x008 ......................................................................... 79
Register 14: Device Capabilities 1 (DC1), offset 0x010 ......................................................................... 80
Register 15: Device Capabilities 2 (DC2), offset 0x014 ......................................................................... 82
Register 16: Device Capabilities 3 (DC3), offset 0x018 ......................................................................... 84
Register 17: Device Capabilities 4 (DC4), offset 0x01C ......................................................................... 86
Register 18: Run Mode Clock Gating Control Register 0 (RCGC0), offset 0x100 .................................... 87
Register 19: Sleep Mode Clock Gating Control Register 0 (SCGC0), offset 0x110 .................................. 89
Register 20: Deep Sleep Mode Clock Gating Control Register 0 (DCGC0), offset 0x120 ......................... 91
Register 21: Run Mode Clock Gating Control Register 1 (RCGC1), offset 0x104 .................................... 93
Register 22: Sleep Mode Clock Gating Control Register 1 (SCGC1), offset 0x114 .................................. 95
Register 23: Deep Sleep Mode Clock Gating Control Register 1 (DCGC1), offset 0x124 ......................... 97
Register 24: Run Mode Clock Gating Control Register 2 (RCGC2), offset 0x108 .................................... 99
Register 25: Sleep Mode Clock Gating Control Register 2 (SCGC2), offset 0x118 ................................. 101
Register 26: Deep Sleep Mode Clock Gating Control Register 2 (DCGC2), offset 0x128 ....................... 103
Register 27: Software Reset Control 0 (SRCR0), offset 0x040 ............................................................. 105
Register 28: Software Reset Control 1 (SRCR1), offset 0x044 ............................................................. 106
Register 29: Software Reset Control 2 (SRCR2), offset 0x048 ............................................................. 108
Internal Memory ........................................................................................................................... 109
Register 1: Flash Memory Address (FMA), offset 0x000 .................................................................... 114
Register 2: Flash Memory Data (FMD), offset 0x004 ......................................................................... 115
Register 3: Flash Memory Control (FMC), offset 0x008 ..................................................................... 116
Register 4: Flash Controller Raw Interrupt Status (FCRIS), offset 0x00C ............................................ 118
Register 5: Flash Controller Interrupt Mask (FCIM), offset 0x010 ........................................................ 119
Register 6: Flash Controller Masked Interrupt Status and Clear (FCMISC), offset 0x014 ..................... 120
Register 7: USec Reload (USECRL), offset 0x140 ............................................................................ 121
Register 8: Flash Memory Protection Read Enable 0 (FMPRE0), offset 0x130 and 0x200 ................... 122
Register 9: Flash Memory Protection Program Enable 0 (FMPPE0), offset 0x134 and 0x400 ............... 123
Register 10: User Debug (USER_DBG), offset 0x1D0 ......................................................................... 124
Register 11: User Register 0 (USER_REG0), offset 0x1E0 .................................................................. 125
Register 12: User Register 1 (USER_REG1), offset 0x1E4 .................................................................. 126
Register 13: Flash Memory Protection Read Enable 1 (FMPRE1), offset 0x204 .................................... 127
Register 14: Flash Memory Protection Read Enable 2 (FMPRE2), offset 0x208 .................................... 128
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Register 15: Flash Memory Protection Read Enable 3 (FMPRE3), offset 0x20C ................................... 129
Register 16: Flash Memory Protection Program Enable 1 (FMPPE1), offset 0x404 ............................... 130
Register 17: Flash Memory Protection Program Enable 2 (FMPPE2), offset 0x408 ............................... 131
Register 18: Flash Memory Protection Program Enable 3 (FMPPE3), offset 0x40C ............................... 132
GPIO .............................................................................................................................................. 133
Register 1: GPIO Data (GPIODATA), offset 0x000 ............................................................................ 140
Register 2: GPIO Direction (GPIODIR), offset 0x400 ......................................................................... 141
Register 3: GPIO Interrupt Sense (GPIOIS), offset 0x404 .................................................................. 142
Register 4: GPIO Interrupt Both Edges (GPIOIBE), offset 0x408 ........................................................ 143
Register 5: GPIO Interrupt Event (GPIOIEV), offset 0x40C ................................................................ 144
Register 6: GPIO Interrupt Mask (GPIOIM), offset 0x410 ................................................................... 145
Register 7: GPIO Raw Interrupt Status (GPIORIS), offset 0x414 ........................................................ 146
Register 8: GPIO Masked Interrupt Status (GPIOMIS), offset 0x418 ................................................... 147
Register 9: GPIO Interrupt Clear (GPIOICR), offset 0x41C ................................................................ 148
Register 10: GPIO Alternate Function Select (GPIOAFSEL), offset 0x420 ............................................ 149
Register 11: GPIO 2-mA Drive Select (GPIODR2R), offset 0x500 ........................................................ 151
Register 12: GPIO 4-mA Drive Select (GPIODR4R), offset 0x504 ........................................................ 152
Register 13: GPIO 8-mA Drive Select (GPIODR8R), offset 0x508 ........................................................ 153
Register 14: GPIO Open Drain Select (GPIOODR), offset 0x50C ......................................................... 154
Register 15: GPIO Pull-Up Select (GPIOPUR), offset 0x510 ................................................................ 155
Register 16: GPIO Pull-Down Select (GPIOPDR), offset 0x514 ........................................................... 156
Register 17: GPIO Slew Rate Control Select (GPIOSLR), offset 0x518 ................................................ 157
Register 18: GPIO Digital Enable (GPIODEN), offset 0x51C ................................................................ 158
Register 19: GPIO Lock (GPIOLOCK), offset 0x520 ............................................................................ 159
Register 20: GPIO Commit (GPIOCR), offset 0x524 ............................................................................ 160
Register 21: GPIO Peripheral Identification 4 (GPIOPeriphID4), offset 0xFD0 ....................................... 162
Register 22: GPIO Peripheral Identification 5 (GPIOPeriphID5), offset 0xFD4 ....................................... 163
Register 23: GPIO Peripheral Identification 6 (GPIOPeriphID6), offset 0xFD8 ....................................... 164
Register 24: GPIO Peripheral Identification 7 (GPIOPeriphID7), offset 0xFDC ...................................... 165
Register 25: GPIO Peripheral Identification 0 (GPIOPeriphID0), offset 0xFE0 ....................................... 166
Register 26: GPIO Peripheral Identification 1(GPIOPeriphID1), offset 0xFE4 ........................................ 167
Register 27: GPIO Peripheral Identification 2 (GPIOPeriphID2), offset 0xFE8 ....................................... 168
Register 28: GPIO Peripheral Identification 3 (GPIOPeriphID3), offset 0xFEC ...................................... 169
Register 29: GPIO PrimeCell Identification 0 (GPIOPCellID0), offset 0xFF0 .......................................... 170
Register 30: GPIO PrimeCell Identification 1 (GPIOPCellID1), offset 0xFF4 .......................................... 171
Register 31: GPIO PrimeCell Identification 2 (GPIOPCellID2), offset 0xFF8 .......................................... 172
Register 32: GPIO PrimeCell Identification 3 (GPIOPCellID3), offset 0xFFC ......................................... 173
Timers ........................................................................................................................................... 174
Register 1: GPTM Configuration (GPTMCFG), offset 0x000 .............................................................. 186
Register 2: GPTM TimerA Mode (GPTMTAMR), offset 0x004 ............................................................ 187
Register 3: GPTM TimerB Mode (GPTMTBMR), offset 0x008 ............................................................ 188
Register 4: GPTM Control (GPTMCTL), offset 0x00C ........................................................................ 189
Register 5: GPTM Interrupt Mask (GPTMIMR), offset 0x018 .............................................................. 191
Register 6: GPTM Raw Interrupt Status (GPTMRIS), offset 0x01C ..................................................... 193
Register 7: GPTM Masked Interrupt Status (GPTMMIS), offset 0x020 ................................................ 194
Register 8: GPTM Interrupt Clear (GPTMICR), offset 0x024 .............................................................. 195
Register 9: GPTM TimerA Interval Load (GPTMTAILR), offset 0x028 ................................................. 197
Register 10: GPTM TimerB Interval Load (GPTMTBILR), offset 0x02C ................................................ 198
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13June 26, 2007
Table of Contents
Register 11: GPTM TimerA Match (GPTMTAMATCHR), offset 0x030 ................................................... 199
Register 12: GPTM TimerB Match (GPTMTBMATCHR), offset 0x034 .................................................. 200
Register 13: GPTM TimerA Prescale (GPTMTAPR), offset 0x038 ........................................................ 201
Register 14: GPTM TimerB Prescale (GPTMTBPR), offset 0x03C ....................................................... 202
Register 15: GPTM TimerA Prescale Match (GPTMTAPMR), offset 0x040 ........................................... 203
Register 16: GPTM TimerB Prescale Match (GPTMTBPMR), offset 0x044 ........................................... 204
Register 17: GPTM TimerA (GPTMTAR), offset 0x048 ........................................................................ 205
Register 18: GPTM TimerB (GPTMTBR), offset 0x04C ....................................................................... 206
Watchdog Timer ........................................................................................................................... 207
Register 1: Watchdog Load (WDTLOAD), offset 0x000 ...................................................................... 210
Register 2: Watchdog Value (WDTVALUE), offset 0x004 ................................................................... 211
Register 3: Watchdog Control (WDTCTL), offset 0x008 ..................................................................... 212
Register 4: Watchdog Interrupt Clear (WDTICR), offset 0x00C .......................................................... 213
Register 5: Watchdog Raw Interrupt Status (WDTRIS), offset 0x010 .................................................. 214
Register 6: Watchdog Masked Interrupt Status (WDTMIS), offset 0x014 ............................................. 215
Register 7: Watchdog Test (WDTTEST), offset 0x418 ....................................................................... 216
Register 8: Watchdog Lock (WDTLOCK), offset 0xC00 ..................................................................... 217
Register 9: Watchdog Peripheral Identification 4 (WDTPeriphID4), offset 0xFD0 ................................. 218
Register 10: Watchdog Peripheral Identification 5 (WDTPeriphID5), offset 0xFD4 ................................. 219
Register 11: Watchdog Peripheral Identification 6 (WDTPeriphID6), offset 0xFD8 ................................. 220
Register 12: Watchdog Peripheral Identification 7 (WDTPeriphID7), offset 0xFDC ................................ 221
Register 13: Watchdog Peripheral Identification 0 (WDTPeriphID0), offset 0xFE0 ................................. 222
Register 14: Watchdog Peripheral Identification 1 (WDTPeriphID1), offset 0xFE4 ................................. 223
Register 15: Watchdog Peripheral Identification 2 (WDTPeriphID2), offset 0xFE8 ................................. 224
Register 16: Watchdog Peripheral Identification 3 (WDTPeriphID3), offset 0xFEC ................................. 225
Register 17: Watchdog PrimeCell Identification 0 (WDTPCellID0), offset 0xFF0 .................................... 226
Register 18: Watchdog PrimeCell Identification 1 (WDTPCellID1), offset 0xFF4 .................................... 227
Register 19: Watchdog PrimeCell Identification 2 (WDTPCellID2), offset 0xFF8 .................................... 228
Register 20: Watchdog PrimeCell Identification 3 (WDTPCellID3 ), offset 0xFFC .................................. 229
ADC ............................................................................................................................................... 230
Register 1: ADC Active Sample Sequencer (ADCACTSS), offset 0x000 ............................................. 237
Register 2: ADC Raw Interrupt Status (ADCRIS), offset 0x004 ........................................................... 238
Register 3: ADC Interrupt Mask (ADCIM), offset 0x008 ..................................................................... 239
Register 4: ADC Interrupt Status and Clear (ADCISC), offset 0x00C .................................................. 240
Register 5: ADC Overflow Status (ADCOSTAT), offset 0x010 ............................................................ 241
Register 6: ADC Event Multiplexer Select (ADCEMUX), offset 0x014 ................................................. 242
Register 7: ADC Underflow Status (ADCUSTAT), offset 0x018 ........................................................... 244
Register 8: ADC Sample Sequencer Priority (ADCSSPRI), offset 0x020 ............................................. 245
Register 9: ADC Processor Sample Sequence Initiate (ADCPSSI), offset 0x028 ................................. 246
Register 10: ADC Sample Averaging Control (ADCSAC), offset 0x030 ................................................. 247
Register 11: ADC Sample Sequence Input Multiplexer Select 0 (ADCSSMUX0), offset 0x040 ............... 248
Register 12: ADC Sample Sequence Control 0 (ADCSSCTL0), offset 0x044 ........................................ 250
Register 13: ADC Sample Sequence Result FIFO 0 (ADCSSFIFO0), offset 0x048 ................................ 253
Register 14: ADC Sample Sequence Result FIFO 1 (ADCSSFIFO1), offset 0x068 ................................ 253
Register 15: ADC Sample Sequence Result FIFO 2 (ADCSSFIFO2), offset 0x088 ................................ 253
Register 16: ADC Sample Sequence FIFO 0 Status (ADCSSFSTAT0), offset 0x04C ............................. 254
Register 17: ADC Sample Sequence FIFO 1 Status (ADCSSFSTAT1), offset 0x06C ............................. 254
Register 18: ADC Sample Sequence FIFO 2 Status (ADCSSFSTAT2), offset 0x08C ............................. 254
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LM3S2139 Microcontroller
Register 19: ADC Sample Sequence Input Multiplexer Select 1 (ADCSSMUX1), offset 0x060 ............... 255
Register 20: ADC Sample Sequence Control 1 (ADCSSCTL1), offset 0x064 ........................................ 256
Register 21: ADC Sample Sequence Input Multiplexer Select 2 (ADCSSMUX2), offset 0x080 ............... 258
Register 22: ADC Sample Sequence Control 2 (ADCSSCTL2), offset 0x084 ........................................ 259
Register 23: ADC Sample Sequence Input Multiplexer Select 3 (ADCSSMUX3), offset 0x0A0 ............... 261
Register 24: ADC Sample Sequence Control 3 (ADCSSCTL3), offset 0x0A4 ........................................ 262
Register 25: ADC Sample Sequence Result FIFO 3 (ADCSSFIFO3), offset 0x0A8 ............................... 263
Register 26: ADC Sample Sequence FIFO 3 Status (ADCSSFSTAT3), offset 0x0AC ............................ 264
Register 27: ADC Test Mode Loopback (ADCTMLB), offset 0x100 ....................................................... 265
UART ............................................................................................................................................. 267
Register 1: UART Data (UARTDR), offset 0x000 ............................................................................... 275
Register 2: UART Receive Status/Error Clear (UARTRSR/UARTECR), offset 0x004 ........................... 277
Register 3: UART Flag (UARTFR), offset 0x018 ................................................................................ 279
Register 4: UART IrDA Low-Power Register (UARTILPR), offset 0x020 ............................................. 281
Register 5: UART Integer Baud-Rate Divisor (UARTIBRD), offset 0x024 ............................................ 282
Register 6: UART Fractional Baud-Rate Divisor (UARTFBRD), offset 0x028 ....................................... 283
Register 7: UART Line Control (UARTLCRH), offset 0x02C ............................................................... 284
Register 8: UART Control (UARTCTL), offset 0x030 ......................................................................... 286
Register 9: UART Interrupt FIFO Level Select (UARTIFLS), offset 0x034 ........................................... 288
Register 10: UART Interrupt Mask (UARTIM), offset 0x038 ................................................................. 289
Register 11: UART Raw Interrupt Status (UARTRIS), offset 0x03C ...................................................... 291
Register 12: UART Masked Interrupt Status (UARTMIS), offset 0x040 ................................................. 292
Register 13: UART Interrupt Clear (UARTICR), offset 0x044 ............................................................... 293
Register 14: UART Peripheral Identification 4 (UARTPeriphID4), offset 0xFD0 ..................................... 295
Register 15: UART Peripheral Identification 5 (UARTPeriphID5), offset 0xFD4 ..................................... 296
Register 16: UART Peripheral Identification 6 (UARTPeriphID6), offset 0xFD8 ..................................... 297
Register 17: UART Peripheral Identification 7 (UARTPeriphID7), offset 0xFDC ..................................... 298
Register 18: UART Peripheral Identification 0 (UARTPeriphID0), offset 0xFE0 ...................................... 299
Register 19: UART Peripheral Identification 1 (UARTPeriphID1), offset 0xFE4 ...................................... 300
Register 20: UART Peripheral Identification 2 (UARTPeriphID2), offset 0xFE8 ...................................... 301
Register 21: UART Peripheral Identification 3 (UARTPeriphID3), offset 0xFEC ..................................... 302
Register 22: UART PrimeCell Identification 0 (UARTPCellID0), offset 0xFF0 ........................................ 303
Register 23: UART PrimeCell Identification 1 (UARTPCellID1), offset 0xFF4 ........................................ 304
Register 24: UART PrimeCell Identification 2 (UARTPCellID2), offset 0xFF8 ........................................ 305
Register 25: UART PrimeCell Identification 3 (UARTPCellID3), offset 0xFFC ........................................ 306
SSI ................................................................................................................................................. 307
Register 1: SSI Control 0 (SSICR0), offset 0x000 .............................................................................. 319
Register 2: SSI Control 1 (SSICR1), offset 0x004 .............................................................................. 321
Register 3: SSI Data (SSIDR), offset 0x008 ...................................................................................... 322
Register 4: SSI Status (SSISR), offset 0x00C ................................................................................... 323
Register 5: SSI Clock Prescale (SSICPSR), offset 0x010 .................................................................. 324
Register 6: SSI Interrupt Mask (SSIIM), offset 0x014 ......................................................................... 325
Register 7: SSI Raw Interrupt Status (SSIRIS), offset 0x018 .............................................................. 326
Register 8: SSI Masked Interrupt Status (SSIMIS), offset 0x01C ........................................................ 327
Register 9: SSI Interrupt Clear (SSIICR), offset 0x020 ....................................................................... 328
Register 10: SSI Peripheral Identification 4 (SSIPeriphID4), offset 0xFD0 ............................................. 329
Register 11: SSI Peripheral Identification 5 (SSIPeriphID5), offset 0xFD4 ............................................. 330
Register 12: SSI Peripheral Identification 6 (SSIPeriphID6), offset 0xFD8 ............................................. 331
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15June 26, 2007
Table of Contents
Register 13: SSI Peripheral Identification 7 (SSIPeriphID7), offset 0xFDC ............................................ 332
Register 14: SSI Peripheral Identification 0 (SSIPeriphID0), offset 0xFE0 ............................................. 333
Register 15: SSI Peripheral Identification 1 (SSIPeriphID1), offset 0xFE4 ............................................. 334
Register 16: SSI Peripheral Identification 2 (SSIPeriphID2), offset 0xFE8 ............................................. 335
Register 17: SSI Peripheral Identification 3 (SSIPeriphID3), offset 0xFEC ............................................ 336
Register 18: SSI PrimeCell Identification 0 (SSIPCellID0), offset 0xFF0 ............................................... 337
Register 19: SSI PrimeCell Identification 1 (SSIPCellID1), offset 0xFF4 ............................................... 338
Register 20: SSI PrimeCell Identification 2 (SSIPCellID2), offset 0xFF8 ............................................... 339
Register 21: SSI PrimeCell Identification 3 (SSIPCellID3), offset 0xFFC ............................................... 340
Inter-Integrated Circuit (I2C) Interface ........................................................................................ 341
Register 1: I2C Master Slave Address (I2CMSA), offset 0x000 ........................................................... 355
Register 2: I2C Master Control/Status (I2CMCS), offset 0x004 ........................................................... 356
Register 3: I2C Master Data (I2CMDR), offset 0x008 ......................................................................... 360
Register 4: I2C Master Timer Period (I2CMTPR), offset 0x00C ........................................................... 361
Register 5: I2C Master Interrupt Mask (I2CMIMR), offset 0x010 ......................................................... 362
Register 6: I2C Master Raw Interrupt Status (I2CMRIS), offset 0x014 ................................................. 363
Register 7: I2C Master Masked Interrupt Status (I2CMMIS), offset 0x018 ........................................... 364
Register 8: I2C Master Interrupt Clear (I2CMICR), offset 0x01C ......................................................... 365
Register 9: I2C Master Configuration (I2CMCR), offset 0x020 ............................................................ 366
Register 10: I2C Slave Own Address (I2CSOAR), offset 0x000 ............................................................ 368
Register 11: I2C Slave Control/Status (I2CSCSR), offset 0x004 ........................................................... 369
Register 12: I2C Slave Data (I2CSDR), offset 0x008 ........................................................................... 371
Register 13: I2C Slave Interrupt Mask (I2CSIMR), offset 0x00C ........................................................... 372
Register 14: I2C Slave Raw Interrupt Status (I2CSRIS), offset 0x010 ................................................... 373
Register 15: I2C Slave Masked Interrupt Status (I2CSMIS), offset 0x014 .............................................. 374
Register 16: I2C Slave Interrupt Clear (I2CSICR), offset 0x018 ............................................................ 375
CAN ............................................................................................................................................... 376
Register 1: CAN Control (CANCTL), offset 0x000 ............................................................................. 390
Register 2: CAN Status (CANSTS), offset 0x004 ............................................................................... 392
Register 3: CAN Error Counter (CANERR), offset 0x008 ................................................................... 395
Register 4: CAN Bit Timing (CANBIT), offset 0x00C .......................................................................... 396
Register 5: CAN Interrupt (CANINT), offset 0x010 ............................................................................. 398
Register 6: CAN Test (CANTST), offset 0x014 .................................................................................. 399
Register 7: CAN Baud Rate Prescalar Extension (CANBRPE), offset 0x018 ....................................... 401
Register 8: CAN IF1 Command Request (CANIF1CRQ), offset 0x020 ................................................ 402
Register 9: CAN IF2 Command Request (CANIF2CRQ), offset 0x080 ................................................ 402
Register 10: CAN IF1 Command Mask (CANIF1CMSK), offset 0x024 .................................................. 403
Register 11: CAN IF2 Command Mask (CANIF2CMSK), offset 0x084 .................................................. 403
Register 12: CAN IF1 Mask 1 (CANIF1MSK1), offset 0x028 ................................................................ 406
Register 13: CAN IF2 Mask 1 (CANIF2MSK1), offset 0x088 ................................................................ 406
Register 14: CAN IF1 Mask 2 (CANIF1MSK2), offset 0x02C ................................................................ 407
Register 15: CAN IF2 Mask 2 (CANIF2MSK2), offset 0x08C ................................................................ 407
Register 16: CAN IF1 Arbitration 1 (CANIF1ARB1), offset 0x030 ......................................................... 408
Register 17: CAN IF2 Arbitration 1 (CANIF2ARB1), offset 0x090 ......................................................... 408
Register 18: CAN IF1 Arbitration 2 (CANIF1ARB2), offset 0x034 ......................................................... 409
Register 19: CAN IF2 Arbitration 2 (CANIF2ARB2), offset 0x094 ......................................................... 409
Register 20: CAN IF1 Message Control (CANIF1MCTL), offset 0x038 .................................................. 410
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LM3S2139 Microcontroller
Register 21: CAN IF2 Message Control (CANIF2MCTL), offset 0x098 .................................................. 410
Register 22: CAN IF1 Data A1 (CANIF1DA1), offset 0x03C ................................................................. 412
Register 23: CAN IF2 Data A1 (CANIF2DA1), offset 0x09C ................................................................. 412
Register 24: CAN IF1 Data A2 (CANIF1DA2), offset 0x040 ................................................................. 413
Register 25: CAN IF2 Data A2 (CANIF2DA2), offset 0x0A0 ................................................................. 413
Register 26: CAN IF1 Data B1 (CANIF1DB1), offset 0x044 ................................................................. 414
Register 27: CAN IF2 Data B1 (CANIF2DB1), offset 0x0A4 ................................................................. 414
Register 28: CAN IF1 Data B2 (CANIF1DB2), offset 0x048 ................................................................. 415
Register 29: CAN IF2 Data B2 (CANIF2DB2), offset 0x0A8 ................................................................. 415
Register 30: CAN Transmission Request 1 (CANTXRQ1), offset 0x100 ................................................ 416
Register 31: CAN Transmission Request 2 (CANTXRQ2), offset 0x104 ................................................ 416
Register 32: CAN New Data 1 (CANNWDA1), offset 0x120 ................................................................. 417
Register 33: CAN New Data 2 (CANNWDA2), offset 0x124 ................................................................. 417
Register 34: CAN Message 1 Interrupt Pending (CANMSG1INT), offset 0x140 ..................................... 418
Register 35: CAN Message 2 Interrupt Pending (CANMSG2INT), offset 0x144 ..................................... 418
Register 36: CAN Message 1 Valid (CANMSG1VAL), offset 0x160 ....................................................... 419
Register 37: CAN Message 2 Valid (CANMSG2VAL), offset 0x164 ....................................................... 419
Analog Comparators ................................................................................................................... 420
Register 1: Analog Comparator Masked Interrupt Status (ACMIS), offset 0x00 .................................... 426
Register 2: Analog Comparator Raw Interrupt Status (ACRIS), offset 0x04 ......................................... 427
Register 3: Analog Comparator Interrupt Enable (ACINTEN), offset 0x08 ........................................... 428
Register 4: Analog Comparator Reference Voltage Control (ACREFCTL), offset 0x10 ......................... 429
Register 5: Analog Comparator Status 0 (ACSTAT0), offset 0x20 ....................................................... 430
Register 6: Analog Comparator Status 1 (ACSTAT1), offset 0x40 ....................................................... 430
Register 7: Analog Comparator Status 2 (ACSTAT2), offset 0x60 ....................................................... 430
Register 8: Analog Comparator Control 0 (ACCTL0), offset 0x24 ....................................................... 431
Register 9: Analog Comparator Control 1 (ACCTL1), offset 0x44 ....................................................... 431
Register 10: Analog Comparator Control 2 (ACCTL2), offset 0x64 ...................................................... 431
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17June 26, 2007

About This Document

About This Document
This data sheet provides reference information for the LM3S2139 microcontroller, describing the functional blocks of the system-on-chip (SoC) device designed around the ARM® Cortex™-M3 core.

Audience

This manual is intended for system software developers, hardware designers, and application developers.

About This Manual

This document is organized into sections that correspond to each major feature.

Related Documents

The following documents are referenced by the data sheet, and available on the documentation CD or from the Luminary Micro web site at www.luminarymicro.com:
ARM® Cortex™-M3 Technical Reference Manual
ARM® CoreSight Technical Reference Manual
ARM® v7-M Architecture Application Level Reference Manual
The following related documents are also referenced:
IEEE Standard 1149.1-Test Access Port and Boundary-Scan Architecture
This documentation list was current as of publication date. Please check the Luminary Micro web site for additional documentation, including application notes and white papers.

Documentation Conventions

This document uses the conventions shown in Table 1 on page 18.
Table 1. Documentation Conventions
MeaningNotation
General Register Notation
REGISTER
offset 0xnnn
Register N
APB registers are indicated in uppercase bold. For example, PBORCTL is the Power-On and Brown-Out Reset Control register. If a register name contains a lowercase n, it represents more than one register. For example, SRCRn represents any (or all) of the three Software Reset Control registers: SRCR0, SRCR1 , and SRCR2.
A single bit in a register.bit
Two or more consecutive and related bits.bit field
A hexadecimal increment to a register's address, relative to that module's base address as specified in “Memory Map” on page 38.
Registers are numbered consecutively throughout the document to aid in referencing them. The register number has no meaning to software.
Preliminary
June 26, 200718
reserved
yy:xx
Register Bit/Field Types
R/W1C
W1C
Reset Value
Pin/Signal Notation
assert a signal
SIGNAL
SIGNAL
Numbers
X
0x
LM3S2139 Microcontroller
MeaningNotation
Register bits marked reserved are reserved for future use. In most cases, reserved bits are set to 0; however, user software should not rely on the value of a reserved bit. To provide software compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
The range of register bits inclusive from xx to yy. For example, 31:15 means bits 15 through 31 in that register.
This value in the register bit diagram indicates whether software running on the controller can change the value of the bit field.
Software can read this field. The bit or field is cleared by hardware after reading the bit/field.RC
Software can read this field. Always write the chip reset value.RO
Software can read or write this field.R/W
Software can read or write this field. A write of a 0 to a W1C bit does not affect the bit value in the register. A write of a 1 clears the value of the bit in the register; the remaining bits remain unchanged.
This register type is primarily used for clearing interrupt status bits where the read operation provides the interrupt status and the write of the read value clears only the interrupts being reported at the time the register was read.
Software can write this field. A write of a 0 to a W1C bit does not affect the bit value in the register. A write of a 1 clears the value of the bit in the register; the remaining bits remain unchanged. A read of the register returns no meaningful data.
This register is typically used to clear the corresponding bit in an interrupt register.
Only a write by software is valid; a read of the register returns no meaningful data.WO
This value in the register bit diagram shows the bit/field value after any reset, unless noted.Register Bit/Field
Bit cleared to 0 on chip reset.0
Bit set to 1 on chip reset.1
Nondeterministic.-
Pin alternate function; a pin defaults to the signal without the brackets.[ ]
Refers to the physical connection on the package.pin
Refers to the electrical signal encoding of a pin.signal
Change the value of the signal from the logically False state to the logically True state. For active High signals, the asserted signal value is 1 (High); for active Low signals, the asserted signal value is 0 (Low). The active polarity (High or Low) is defined by the signal name (see SIGNAL and SIGNAL below).
Change the value of the signal from the logically True state to the logically False state.deassert a signal
Signal names are in uppercase and in the Courier font. An overbar on a signal name indicates that it is active Low. To assert SIGNAL is to drive it Low; to deassert SIGNAL is to drive it High.
Signal names are in uppercase and in the Courier font. An active High signal has no overbar. To assert SIGNAL is to drive it High; to deassert SIGNAL is to drive it Low.
An uppercase X indicates any of several values is allowed, where X can be any legal pattern. For example, a binary value of 0X00 can be either 0100 or 0000, a hex value of 0xX is 0x0 or 0x1, and so on.
Hexadecimal numbers have a prefix of 0x. For example, 0x00FF is the hexadecimal number FF. Binary numbers are indicated with a b suffix, for example, 1011b. Decimal numbers are written without a prefix or suffix.
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19June 26, 2007

Architectural Overview

1 Architectural Overview
The Luminary Micro Stellaris®family of microcontrollers—the first ARM® Cortex™-M3 based controllers—brings high-performance 32-bit computing to cost-sensitive embedded microcontroller applications. These pioneering parts deliver customers 32-bit performance at a cost equivalent to legacy 8- and 16-bit devices, all in a package with a small footprint.
The Stellaris®family offers efficient performance and extensive integration, favorably positioning the device into cost-conscious applications requiring significant control-processing and connectivity capabilities. The Stellaris®LM3S2000 series, designed for Controller Area Network (CAN) applications, extends the Stellaris family with Bosch CAN networking technology, the golden standard in short-haul industrial networks. The Stellaris®LM3S2000 series also marks the first integration of CAN capabilities with the revolutionary Cortex-M3 core. The Stellaris®LM3S6000 series combines both a 10/100 Ethernet Media Access Control (MAC) and Physical (PHY) layer, marking the first time that integrated connectivity is available with an ARM Cortex-M3 MCU and the only integrated 10/100 Ethernet MAC and PHY available in an ARM architecture MCU.
The LM3S2139 microcontroller is targeted for industrial applications, including remote monitoring, electronic point-of-sale machines, test and measurement equipment, network appliances and switches, factory automation, HVAC and building control, gaming equipment, motion control, medical instrumentation, and fire and security.
In addition, the LM3S2139 microcontroller offers the advantages of ARM's widely available development tools, System-on-Chip (SoC) infrastructure IP applications, and a large user community. Additionally, the microcontroller uses ARM's Thumb®-compatible Thumb-2 instruction set to reduce memory requirements and, thereby, cost. Finally, the LM3S2139 microcontroller is code-compatible to all members of the extensive Stellaris®family; providing flexibility to fit our customers' precise needs.
Luminary Micro offers a complete solution to get to market quickly, with evaluation and development boards, white papers and application notes, an easy-to-use peripheral driver library, and a strong support, sales, and distributor network.

1.1 Product Features

The LM3S2139 microcontroller includes the following product features:
32-Bit RISC Performance
32-bit ARM® Cortex™-M3 v7M architecture optimized for small-footprint embedded
applications
System timer (SysTick), providing a simple, 24-bit clear-on-write, decrementing, wrap-on-zero
counter with a flexible control mechanism
Thumb®-compatible Thumb-2-only instruction set processor core for high code density
25-MHz operation
Hardware-division and single-cycle-multiplication
Integrated Nested Vectored Interrupt Controller (NVIC) providing deterministic interrupt
handling
29 interrupts with eight priority levels
June 26, 200720
Preliminary
LM3S2139 Microcontroller
Memory protection unit (MPU), providing a privileged mode for protected operating system
functionality
Unaligned data access, enabling data to be efficiently packed into memory
Atomic bit manipulation (bit-banding), delivering maximum memory utilization and streamlined
peripheral control
Internal Memory
64 KB single-cycle flash
User-managed flash block protection on a 2-KB block basis
User-managed flash data programming
User-defined and managed flash-protection block
16 KB single-cycle SRAM
General-Purpose Timers
Three General-Purpose Timer Modules (GPTM), each of which provides two 16-bit
timer/counters. Each GPTM can be configured to operate independently as timers or event counters (eight total): as a single 32-bit timer (four total), as one 32-bit Real-Time Clock (RTC) to event capture, for Pulse Width Modulation (PWM), or to trigger analog-to-digital conversions
32-bit Timer modes
Programmable one-shot timer
Programmable periodic timer
Real-Time Clock when using an external 32.768-KHz clock as the input
User-enabled stalling in periodic and one-shot mode when the controller asserts the CPU Halt flag during debug
ADC event trigger
16-bit Timer modes
General-purpose timer function with an 8-bit prescaler
Programmable one-shot timer
Programmable periodic timer
User-enabled stalling when the controller asserts CPU Halt flag during debug
ADC event trigger
16-bit Input Capture modes
Input edge count capture
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21June 26, 2007
Architectural Overview
Input edge time capture
16-bit PWM mode
Simple PWM mode with software-programmable output inversion of the PWM signal
ARM FiRM-compliant Watchdog Timer
32-bit down counter with a programmable load register
Separate watchdog clock with an enable
Programmable interrupt generation logic with interrupt masking
Lock register protection from runaway software
Reset generation logic with an enable/disable
User-enabled stalling when the controller asserts the CPU Halt flag during debug
Controller Area Network (CAN)
Supports CAN protocol version 2.0 part A/B
Bit rates up to 1Mb/s
32 message objects, each with its own identifier mask
Maskable interrupt
Disable automatic retransmission mode for TTCAN
Programmable loop-back mode for self-test operation
Synchronous Serial Interface (SSI)
Master or slave operation
Programmable clock bit rate and prescale
Separate transmit and receive FIFOs, 16 bits wide, 8 locations deep
Programmable interface operation for Freescale SPI, MICROWIRE, or Texas Instruments
synchronous serial interfaces
Programmable data frame size from 4 to 16 bits
Internal loopback test mode for diagnostic/debug testing
UART
Two fully programmable 16C550-type UARTs with IrDA support
Separate 16x8 transmit (TX) and 16x12 receive (RX) FIFOs to reduce CPU interrupt service
loading
Programmable baud-rate generator with fractional divider
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Preliminary
LM3S2139 Microcontroller
Programmable FIFO length, including 1-byte deep operation providing conventional
double-buffered interface
FIFO trigger levels of 1/8, ¼, ½, ¾, and 7/8
Standard asynchronous communication bits for start, stop, and parity
False-start-bit detection
Line-break generation and detection
ADC
Single- and differential-input configurations
Four 10-bit channels (inputs) when used as single-ended inputs
Sample rate of 250 thousand samples/second
Flexible, configurable analog-to-digital conversion
Four programmable sample conversion sequences from one to eight entries long, with
corresponding conversion result FIFOs
Each sequence triggered by software or internal event (timers, analog comparators, or GPIO)
On-chip temperature sensor
Analog Comparators
Three independent integrated analog comparators
Configurable for output to: drive an output pin, generate an interrupt, or initiate an ADC sample
sequence
Compare external pin input to external pin input or to internal programmable voltage reference
I2C
Master and slave receive and transmit operation with transmission speed up to 100 Kbps in
Standard mode and 400 Kbps in Fast mode
Interrupt generation
Master with arbitration and clock synchronization, multimaster support, and 7-bit addressing
mode
GPIOs
24-56 GPIOs, depending on configuration
5-V-tolerant input/outputs
Programmable interrupt generation as either edge-triggered or level-sensitive
Bit masking in both read and write operations through address lines
Preliminary
23June 26, 2007
Architectural Overview
Can initiate an ADC sample sequence
Programmable control for GPIO pad configuration:
Weak pull-up or pull-down resistors
2-mA, 4-mA, and 8-mA pad drive
Slew rate control for the 8-mA drive
Open drain enables
Digital input enables
Power
On-chip Low Drop-Out (LDO) voltage regulator, with programmable output user-adjustable
from 2.25 V to 2.75 V
Low-power options on controller: Sleep and Deep-sleep modes
Low-power options for peripherals: software controls shutdown of individual peripherals
User-enabled LDO unregulated voltage detection and automatic reset
3.3-V supply brown-out detection and reporting via interrupt or reset
Flexible Reset Sources
Power-on reset (POR)
Reset pin assertion
Brown-out (BOR) detector alerts to system power drops
Software reset
Watchdog timer reset
Internal low drop-out (LDO) regulator output goes unregulated
Additional Features
Six reset sources
Programmable clock source control
Clock gating to individual peripherals for power savings
IEEE 1149.1-1990 compliant Test Access Port (TAP) controller
Debug access via JTAG and Serial Wire interfaces
Full JTAG boundary scan
Industrial-range 100-pin RoHS-compliant LQFP package
Preliminary
June 26, 200724

1.2 Target Applications

Remote monitoring
Electronic point-of-sale (POS) machines
Test and measurement equipment
Network appliances and switches
Factory automation
HVAC and building control
Gaming equipment
Motion control
Medical instrumentation
Fire and security
LM3S2139 Microcontroller
Power and energy
Transportation

1.3 High-Level Block Diagram

Figure 1-1 on page 26 shows the features on the Stellaris® Fury-class family of devices.
Preliminary
25June 26, 2007
LDO Voltage
Regulator
3 Analog
Comparators
ANALOG
10-bit ADC
8 channel
1 Msps
Temp Sensor
Clocks, Reset
System Control
4 Timer/PWM/CCP
Each 32-bit or 2x16-bit
Watchdog Timer
GPIOs
SYSTEM
Battery-Backed
Hibernate
R T C
Systick Timer
64 KB SRAM
256 KB Flash
2 Quadrature
Encoder Inputs
6 PWM Outputs
MOTION CONTROL
Dead-Band
Generator
Comparators
PWM
Generator
PWM
Interrupt
Timer
3 UARTs
2 SSI/SPI
10/100 Ethernet
MAC + PHY
2 CAN
2 I2C
SERIAL INTERFACES
ARM
®
Cortex™-M3
50 MHz
JTAG
NVIC
SWD
32
32
Architectural Overview
Figure 1-1. Stellaris® Fury-class High-Level Block Diagram

1.4 Functional Overview

The following sections provide an overview of the features of the LM3S2139 microcontroller. The page number in parenthesis indicates where that feature is discussed in detail. Ordering and support information can be found in Appendix B, Ordering and Contact Information on page 466.
Preliminary
June 26, 200726

1.4.1 ARM Cortex™-M3

1.4.1.1 Processor Core (see page 32)
All members of the Stellaris®product family, including the LM3S2139 microcontroller, are designed around an ARM Cortex™-M3 processor core. The ARM Cortex-M3 processor provides the core for a high-performance, low-cost platform that meets the needs of minimal memory implementation, reduced pin count, and low-power consumption, while delivering outstanding computational performance and exceptional system response to interrupts.
“ARM Cortex-M3 Processor Core” on page 32 provides an overview of the ARM core; the core is detailed in the ARM® Cortex™-M3 Technical Reference Manual.
1.4.1.2 System Timer (SysTick)
Cortex-M3 includes an integrated system timer, SysTick. SysTick provides a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. The counter can be used in several different ways, for example:
An RTOS tick timer which fires at a programmable rate (for example, 100 Hz) and invokes a
SysTick routine.
LM3S2139 Microcontroller
A high-speed alarm timer using the system clock.
A variable rate alarm or signal timer—the duration is range-dependent on the reference clock
used and the dynamic range of the counter.
A simple counter. Software can use this to measure time to completion and time used.
An internal clock source control based on missing/meeting durations. The COUNTFLAG bit-field
in the control and status register can be used to determine if an action completed within a set duration, as part of a dynamic clock management control loop.
1.4.1.3 Nested Vectored Interrupt Controller (NVIC)
The LM3S2139 controller includes the ARM Nested Vectored Interrupt Controller (NVIC) on the ARM Cortex-M3 core. The NVIC and Cortex-M3 prioritize and handle all exceptions. All exceptions are handled in Handler Mode. The processor state is automatically stored to the stack on an exception, and automatically restored from the stack at the end of the Interrupt Service Routine (ISR). The vector is fetched in parallel to the state saving, which enables efficient interrupt entry. The processor supports tail-chaining, which enables back-to-back interrupts to be performed without the overhead of state saving and restoration. Software can set eight priority levels on 7 exceptions (system handlers) and 29 interrupts.
“Interrupts” on page 40 provides an overview of the NVIC controller and the interrupt map. Exceptions and interrupts are detailed in the ARM® Cortex™-M3 Technical Reference Manual.

1.4.2 Motor Control Peripherals

To enhance motor control, the LM3S2139 controller features Pulse Width Modulation (PWM) outputs.
1.4.2.1 PWM (see page 180)
Pulse width modulation (PWM) is a powerful technique for digitally encoding analog signal levels. High-resolution counters are used to generate a square wave, and the duty cycle of the square wave is modulated to encode an analog signal. Typical applications include switching power supplies and motor control.
27June 26, 2007
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Architectural Overview
On the LM3S2139, PWM motion control functionality can be achieved through the motion control features of the general-purpose timers (using the CCP pins).
CCP Pins (see page 180)
The General-Purpose Timer Module's CCP (Capture Compare PWM) pins are software programmable to support a simple PWM mode with a software-programmable output inversion of the PWM signal.

1.4.3 Serial Communications Peripherals

The LM3S2139 controller supports both asynchronous and synchronous serial communications with:
Two fully programmable 16C550-type UARTs
One SSI module
One I2C module
One CAN unit
1.4.3.1 UART (see page 267)
A Universal Asynchronous Receiver/Transmitter (UART) is an integrated circuit used for RS-232C serial communications, containing a transmitter (parallel-to-serial converter) and a receiver (serial-to-parallel converter), each clocked separately.
The LM3S2139 controller includes two fully programmable 16C550-type UARTs that support data transfer speeds up to 460.8 Kbps. In addition, each UART is capable of supporting IrDA. (Although similar in functionality to a 16C550 UART, it is not register-compatible.)
Separate 16x8 transmit (TX) and 16x12 receive (RX) FIFOs reduce CPU interrupt service loading. The UART can generate individually masked interrupts from the RX, TX, modem status, and error conditions. The module provides a single combined interrupt when any of the interrupts are asserted and are unmasked.
1.4.3.2 SSI (see page 307)
Synchronous Serial Interface (SSI) is a four-wire bi-directional communications interface.
The LM3S2139 controller includes one SSI module that provides the functionality for synchronous serial communications with peripheral devices, and can be configured to use the Freescale SPI, MICROWIRE, or TI synchronous serial interface frame formats. The size of the data frame is also configurable, and can be set between 4 and 16 bits, inclusive.
The SSI module performs serial-to-parallel conversion on data received from a peripheral device, and parallel-to-serial conversion on data transmitted to a peripheral device. The TX and RX paths are buffered with internal FIFOs, allowing up to eight 16-bit values to be stored independently.
The SSI module can be configured as either a master or slave device. As a slave device, the SSI module can also be configured to disable its output, which allows a master device to be coupled with multiple slave devices.
The SSI module also includes a programmable bit rate clock divider and prescaler to generate the output serial clock derived from the SSI module's input clock. Bit rates are generated based on the input clock and the maximum bit rate is determined by the connected peripheral.
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Preliminary
1.4.3.3 I2C(see page 341)
The Inter-Integrated Circuit (I2C) bus provides bi-directional data transfer through a two-wire design (a serial data line SDA and a serial clock line SCL).
The I2C bus interfaces to external I2C devices such as serial memory (RAMs and ROMs), networking devices, LCDs, tone generators, and so on. The I2C bus may also be used for system testing and diagnostic purposes in product development and manufacture.
The LM3S2139 controller includes one I2C module that provides the ability to communicate to other IC devices over an I2C bus. The I2C bus supports devices that can both transmit and receive (write and read) data.
Devices on the I2C bus can be designated as either a master or a slave. The I2C module supports both sending and receiving data as either a master or a slave, and also supports the simultaneous operation as both a master and a slave. The four I2C modes are: Master Transmit, Master Receive, Slave Transmit, and Slave Receive.
A Stellaris®I2C module can operate at two speeds: Standard (100 Kbps) and Fast (400 Kbps).
Both the I2C master and slave can generate interrupts. The I2C master generates interrupts when a transmit or receive operation completes (or aborts due to an error). The I2C slave generates interrupts when data has been sent or requested by a master.
LM3S2139 Microcontroller
1.4.3.4 Controller Area Network (see page 376)
Controller Area Network (CAN) is a multicast shared serial-bus standard for connecting electronic control units (ECUs). CAN was specifically designed to be robust in electromagnetically noisy environments and can utilize a differential balanced line like RS-485 or a more robust twisted-pair wire. Originally created for automotive purposes, now it is used in many embedded control applications (for example, industrial or medical). Bit rates up to 1Mb/s are possible at network lengths below 40 meters. Decreased bit rates allow longer network distances (for example, 125 Kb/s at 500m).
A transmitter sends a message to all CAN nodes (broadcasting). Each node decides on the basis of the identifier received whether it should process the message. The identifier also determines the priority that the message enjoys in competition for bus access. Each CAN message can transmit from 0 to 8 bytes of user information. The LM3S2139 includes one CAN units.

1.4.4 System Peripherals

1.4.4.1 Programmable GPIOs (see page 133)
General-purpose input/output (GPIO) pins offer flexibility for a variety of connections.
The Stellaris®GPIO module is composed of eight physical GPIO blocks, each corresponding to an individual GPIO port. The GPIO module is FiRM-compliant (compliant to the ARM Foundation IP for Real-Time Microcontrollers specification) and supports 24-56 programmable input/output pins. The number of GPIOs available depends on the peripherals being used (see “Signal Tables” on page 434 for the signals available to each GPIO pin).
The GPIO module features programmable interrupt generation as either edge-triggered or level-sensitive on all pins, programmable control for GPIO pad configuration, and bit masking in both read and write operations through address lines.
1.4.4.2 Three Programmable Timers (see page 174)
Programmable timers can be used to count or time external events that drive the Timer input pins.
Preliminary
29June 26, 2007
Architectural Overview
The Stellaris®General-Purpose Timer Module (GPTM) contains three GPTM blocks. Each GPTM block provides two 16-bit timer/counters that can be configured to operate independently as timers or event counters, or configured to operate as one 32-bit timer or one 32-bit Real-Time Clock (RTC). Timers can also be used to trigger analog-to-digital (ADC) conversions.
When configured in 32-bit mode, a timer can run as a one-shot timer, periodic timer, or Real-Time Clock (RTC). When in 16-bit mode, a timer can run as a one-shot timer or periodic timer, and can extend its precision by using an 8-bit prescaler. A 16-bit timer can also be configured for event capture or Pulse Width Modulation (PWM) generation.
1.4.4.3 Watchdog Timer (see page 207)
A watchdog timer can generate nonmaskable interrupts (NMIs) or a reset when a time-out value is reached. The watchdog timer is used to regain control when a system has failed due to a software error or to the failure of an external device to respond in the expected way.
The Stellaris®Watchdog Timer module consists of a 32-bit down counter, a programmable load register, interrupt generation logic, and a locking register.
The Watchdog Timer can be configured to generate an interrupt to the controller on its first time-out, and to generate a reset signal on its second time-out. Once the Watchdog Timer has been configured, the lock register can be written to prevent the timer configuration from being inadvertently altered.

1.4.5 Memory Peripherals

The LM3S2139 controller offers both SRAM and Flash memory.
1.4.5.1 SRAM (see page 109)
The LM3S2139 static random access memory (SRAM) controller supports 16 KB SRAM. The internal SRAM of the Stellaris®devices is located at offset 0x0000.0000 of the device memory map. To reduce the number of time-consuming read-modify-write (RMW) operations, ARM has introduced bit-banding technology in the new Cortex-M3 processor. With a bit-band-enabled processor, certain regions in the memory map (SRAM and peripheral space) can use address aliases to access individual bits in a single, atomic operation.
1.4.5.2 Flash (see page 110)
The LM3S2139 Flash controller supports 64 KB of flash memory. The flash is organized as a set of 1-KB blocks that can be individually erased. Erasing a block causes the entire contents of the block to be reset to all 1s. These blocks are paired into a set of 2-KB blocks that can be individually protected. The blocks can be marked as read-only or execute-only, providing different levels of code protection. Read-only blocks cannot be erased or programmed, protecting the contents of those blocks from being modified. Execute-only blocks cannot be erased or programmed, and can only be read by the controller instruction fetch mechanism, protecting the contents of those blocks from being read by either the controller or by a debugger.

1.4.6 Additional Features

1.4.6.1 Memory Map (see page 38)
A memory map lists the location of instructions and data in memory. The memory map for the LM3S2139 controller can be found in “Memory Map” on page 38. Register addresses are given as a hexadecimal increment, relative to the module's base address as shown in the memory map.
The ARM® Cortex™-M3 Technical Reference Manual provides further information on the memory map.
June 26, 200730
Preliminary
1.4.6.2 JTAG TAP Controller (see page 42)
The Joint Test Action Group (JTAG) port provides a standardized serial interface for controlling the Test Access Port (TAP) and associated test logic. The TAP, JTAG instruction register, and JTAG data registers can be used to test the interconnects of assembled printed circuit boards, obtain manufacturing information on the components, and observe and/or control the inputs and outputs of the controller during normal operation. The JTAG port provides a high degree of testability and chip-level access at a low cost.
The JTAG port is comprised of the standard five pins: TRST, TCK, TMS, TDI, and TDO. Data is transmitted serially into the controller on TDI and out of the controller on TDO. The interpretation of this data is dependent on the current state of the TAP controller. For detailed information on the operation of the JTAG port and TAP controller, please refer to the IEEE Standard 1149.1-Test Access Port and Boundary-Scan Architecture.
The Luminary Micro JTAG controller works with the ARM JTAG controller built into the Cortex-M3 core. This is implemented by multiplexing the TDO outputs from both JTAG controllers. ARM JTAG instructions select the ARM TDO output while Luminary Micro JTAG instructions select the Luminary Micro TDO outputs. The multiplexer is controlled by the Luminary Micro JTAG controller, which has comprehensive programming for the ARM, Luminary Micro, and unimplemented JTAG instructions.
1.4.6.3 System Control and Clocks (see page 53)
LM3S2139 Microcontroller
System control determines the overall operation of the device. It provides information about the device, controls the clocking of the device and individual peripherals, and handles reset detection and reporting.

1.4.7 Hardware Details

Details on the pins and package can be found in the following sections:
“Pin Diagram” on page 433
“Signal Tables” on page 434
“Operating Characteristics” on page 447
“Electrical Characteristics” on page 448
“Package Information” on page 459
Preliminary
31June 26, 2007

ARM Cortex-M3 Processor Core

2 ARM Cortex-M3 Processor Core
The ARM Cortex-M3 processor provides the core for a high-performance, low-cost platform that meets the needs of minimal memory implementation, reduced pin count, and low power consumption, while delivering outstanding computational performance and exceptional system response to interrupts. Features include:
Compact core.
Thumb-2 instruction set, delivering the high-performance expected of an ARM core in the memory
size usually associated with 8- and 16-bit devices; typically in the range of a few kilobytes of memory for microcontroller class applications.
Speedy application execution through Harvard architecture characterized by separate buses for
instruction and data.
Exceptional interrupt handling, by implementing the register manipulations required for handling
an interrupt in hardware.
Memory protection unit (MPU) to provide a privileged mode of operation for complex applications.
Migration from the ARM7™ processor family for better performance and power efficiency.
Full-featured debug solution with a:
Serial Wire JTAG Debug Port (SWJ-DP)
Flash Patch and Breakpoint (FPB) unit for implementing breakpoints
Data Watchpoint and Trigger (DWT) unit for implementing watchpoints, trigger resources,
and system profiling
Instrumentation Trace Macrocell (ITM) for support of printf style debugging
Trace Port Interface Unit (TPIU) for bridging to a Trace Port Analyzer
The Stellaris®family of microcontrollers builds on this core to bring high-performance 32-bit computing to cost-sensitive embedded microcontroller applications, such as factory automation and control, industrial control power devices, building and home automation, and stepper motors.
For more information on the ARM Cortex-M3 processor core, see the ARM® Cortex™-M3 Technical
Reference Manual. For information on SWJ-DP, see the ARM® CoreSight Technical Reference Manual.
Preliminary
June 26, 200732

2.1 Block Diagram

Private Peripheral
Bus
(internal)
Data
Watchpoint
and Trace
Interrupts
Debug
Sleep
Instrumentation
Trace Macrocell
Trace
Port
Interface
Unit
CM3 Core
Instructions Data
Flash
Patch and
Breakpoint
Memory
Protection
Unit
Adv. High-
Perf. Bus
Access Port
Nested Vectored Interrupt
Controller
Serial Wire JTAG
Debug Port
Bus
Matrix
Adv. Peripheral
Bus
I-code bus D-code bus System bus
ROM Table
Private
Peripheral
Bus
(external)
Serial
Wire
Output
Trace
Port
(SWO)
ARM
Cortex-M3
Figure 2-1. CPU Block Diagram
LM3S2139 Microcontroller

2.2 Functional Description

2.2.1 Serial Wire and JTAG Debug

Important:
Luminary Micro has implemented the ARM Cortex-M3 core as shown in Figure 2-1 on page 33. As noted in the ARM® Cortex™-M3 Technical Reference Manual, several Cortex-M3 components are flexible in their implementation: SW/JTAG-DP, ETM, TPIU, the ROM table, the MPU, and the Nested Vectored Interrupt Controller (NVIC). Each of these is addressed in the sections that follow.
Luminary Micro has replaced the ARM SW-DP and JTAG-DP with the ARM CoreSight™-compliant Serial Wire JTAG Debug Port (SWJ-DP) interface. This means Chapter 12, “Debug Port,” of the ARM® Cortex™-M3 Technical Reference Manual does not apply to Stellaris®devices.
The SWJ-DP interface combines the SWD and JTAG debug ports into one module. See the CoreSight™ Design Kit Technical Reference Manual for details on SWJ-DP.
The ARM® Cortex™-M3 Technical Reference Manual describes all the features of an ARM Cortex-M3 in detail. However, these features differ based on the implementation. This section describes the Stellaris®implementation.
Preliminary
33June 26, 2007
ATB
Interface
Asynchronous FIFO
APB
Interface
Trace Out
(serializer)
Debug
ATB
Slave
Port
APB
Slave
Port
Serial Wire
Trace Port
(SWO)
ARM Cortex-M3 Processor Core

2.2.2 Embedded Trace Macrocell (ETM)

ETM was not implemented in the Stellaris®devices. This means Chapters 15 and 16 of the ARM® Cortex™-M3 Technical Reference Manual can be ignored.

2.2.3 Trace Port Interface Unit (TPIU)

The TPIU acts as a bridge between the Cortex-M3 trace data from the ITM, and an off-chip Trace Port Analyzer. The Stellaris®devices have implemented TPIU as shown in Figure 2-2 on page 34. This is similar to the non-ETM version described in the ARM® Cortex™-M3 Technical Reference Manual, however, SWJ-DP only provides SWV output for the TPIU.
Figure 2-2. TPIU Block Diagram

2.2.4 ROM Table

The default ROM table was implemented as described in the ARM® Cortex™-M3 Technical Reference Manual.

2.2.5 Memory Protection Unit (MPU)

The Memory Protection Unit (MPU) is included on the LM3S2139 controller and supports the standard ARMv7 Protected Memory System Architecture (PMSA) model. The MPU provides full support for

2.2.6 Nested Vectored Interrupt Controller (NVIC)

protection regions, overlapping protection regions, access permissions, and exporting memory attributes to the system.
The Nested Vectored Interrupt Controller (NVIC):
Facilitates low-latency exception and interrupt handling
Preliminary
June 26, 200734
Controls power management
Implements system control registers
The NVIC supports up to 240 dynamically reprioritizable interrupts each with up to 256 levels of priority. The NVIC and the processor core interface are closely coupled, which enables low latency interrupt processing and efficient processing of late arriving interrupts. The NVIC maintains knowledge of the stacked (nested) interrupts to enable tail-chaining of interrupts.
You can only fully access the NVIC from privileged mode, but you can pend interrupts in user-mode if you enable the Configuration Control Register (see the ARM® Cortex™-M3 Technical Reference Manual). Any other user-mode access causes a bus fault.
All NVIC registers are accessible using byte, halfword, and word unless otherwise stated.
All NVIC registers and system debug registers are little endian regardless of the endianness state of the processor.
2.2.6.1 Interrupts
The ARM® Cortex™-M3 Technical Reference Manual describes the maximum number of interrupts and interrupt priorities. The LM3S2139 microcontroller supports 29 interrupts with eight priority levels.
LM3S2139 Microcontroller
2.2.6.2 System Timer (SysTick)
Cortex-M3 includes an integrated system timer, SysTick. SysTick provides a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. The counter can be used in several different ways, for example:
An RTOS tick timer which fires at a programmable rate (for example, 100 Hz) and invokes a
SysTick routine.
A high-speed alarm timer using the system clock.
A variable rate alarm or signal timer—the duration is range-dependent on the reference clock
used and the dynamic range of the counter.
A simple counter. Software can use this to measure time to completion and time used.
An internal clock source control based on missing/meeting durations. The COUNTFLAG bit-field
in the control and status register can be used to determine if an action completed within a set duration, as part of a dynamic clock management control loop.
Functional Description
The timer consists of three registers:
A control and status counter to configure its clock, enable the counter, enable the SysTick
interrupt, and determine counter status.
The reload value for the counter, used to provide the counter's wrap value.
The current value of the counter.
A fourth register, the SysTick Calibration Value Register, is not implemented in the Stellaris®devices.
35June 26, 2007
Preliminary
ARM Cortex-M3 Processor Core
When enabled, the timer counts down from the reload value to zero, reloads (wraps) to the value in the SysTick Reload Value register on the next clock edge, then decrements on subsequent clocks. Writing a value of zero to the Reload Value register disables the counter on the next wrap. When the counter reaches zero, the COUNTFLAG status bit is set. The COUNTFLAG bit clears on reads.
Writing to the Current Value register clears the register and the COUNTFLAG status bit. The write does not trigger the SysTick exception logic. On a read, the current value is the value of the register at the time the register is accessed.
If the core is in debug state (halted), the counter will not decrement. The timer is clocked with respect to a reference clock. The reference clock can be the core clock or an external clock source.
SysTick Control and Status Register
Use the SysTick Control and Status Register to enable the SysTick features. The reset is 0x0000.0000.
DescriptionResetTypeNameBit/Field
Software should not rely on the value of a reserved bit. To provide compatibility with
0ROreserved31:17
future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Returns 1 if timer counted to 0 since last time this was read. Clears on read by
0R/WCOUNTFLAG16
application. If read by the debugger using the DAP, this bit is cleared on read-only if the MasterType bit in the AHB-AP Control Register is set to 0. Otherwise, the COUNTFLAG bit is not changed by the debugger read.
Software should not rely on the value of a reserved bit. To provide compatibility with
0R/Wreserved15:3
future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0 = external reference clock. (Not implemented for Stellaris microcontrollers.)
0R/WCLKSOURCE2
1 = core clock.
If no reference clock is provided, it is held at 1 and so gives the same time as the core clock. The core clock must be at least 2.5 times faster than the reference clock. If it is not, the count values are unpredictable.
1 = counting down to 0 pends the SysTick handler.
0R/WTICKINT1
0 = counting down to 0 does not pend the SysTick handler. Software can use the COUNTFLAG to determine if ever counted to 0.
1 = counter operates in a multi-shot way. That is, counter loads with the Reload
0R/WENABLE0
value and then begins counting down. On reaching 0, it sets the COUNTFLAG to 1 and optionally pends the SysTick handler, based on TICKINT. It then loads the Reload value again, and begins counting.
0 = counter disabled.
SysTick Reload Value Register
Use the SysTick Reload Value Register to specify the start value to load into the current value register when the counter reaches 0. It can be any value between 1 and 0x00FFFFFF. A start value of 0 is possible, but has no effect because the SysTick interrupt and COUNTFLAG are activated when counting from 1 to 0.
Therefore, as a multi-shot timer, repeated over and over, it fires every N+1 clock pulse, where N is any value from 1 to 0x00FFFFFF. So, if the tick interrupt is required every 100 clock pulses, 99 must be written into the RELOAD. If a new value is written on each tick interrupt, so treated as single shot, then the actual count down must be written. For example, if a tick is next required after 400 clock pulses, 400 must be written into the RELOAD.
June 26, 200736
Preliminary
LM3S2139 Microcontroller
DescriptionResetTypeNameBit/Field
Software should not rely on the value of a reserved bit. To provide compatibility with
0ROreserved31:24
future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Value to load into the SysTick Current Value Register when the counter reaches 0.-W1CRELOAD23:0
SysTick Current Value Register
Use the SysTick Current Value Register to find the current value in the register.
DescriptionResetTypeNameBit/Field
Software should not rely on the value of a reserved bit. To provide compatibility with
0ROreserved31:24
future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Current value at the time the register is accessed. No read-modify-write protection is
-W1CCURRENT23:0 provided, so change with care.
This register is write-clear. Writing to it with any value clears the register to 0. Clearing this register also clears the COUNTFLAG bit of the SysTick Control and Status Register.
SysTick Calibration Value Register
The SysTick Calibration Value register is not implemented.
Preliminary
37June 26, 2007

Memory Map

3 Memory Map
The memory map for the LM3S2139 controller is provided in Table 3-1 on page 38.
In this manual, register addresses are given as a hexadecimal increment, relative to the module’s base address as shown in the memory map. See also Chapter 4, “Memory Map” in the ARM® Cortex™-M3 Technical Reference Manual.
Note: In Table 3-1 on page 38 addresses not listed are reserved.
Table 3-1. Memory Map
Memory
0x1FFF.FFFF0x0000.0000
0x200F.FFFF0x2000.0000
FiRM Peripherals
Peripherals
a
DescriptionEndStart
b
c
For details on registers, see page ...
113On-chip flash
113Bit-banded on-chip SRAM
-Reserved non-bit-banded SRAM space0x21FF.FFFF0x2010.0000
109Bit-band alias of 0x2000.0000 through 0x200F.FFFF0x23FF.FFFF0x2200.0000
-Reserved non-bit-banded SRAM space0x3FFF.FFFF0x2400.0000
209Watchdog timer0x4000.0FFF0x4000.0000
-Reserved0x4000.3FFF0x4000.1000
139GPIO Port A0x4000.4FFF0x4000.4000
139GPIO Port B0x4000.5FFF0x4000.5000
139GPIO Port C0x4000.6FFF0x4000.6000
139GPIO Port D0x4000.7FFF0x4000.7000
318SSI00x4000.8FFF0x4000.8000
-Reserved0x4000.BFFF0x4000.A000
274UART00x4000.CFFF0x4000.C000
274UART10x4000.DFFF0x4000.D000
-Reserved0x4000.FFFF0x4000.F000
-Reserved for future FiRM peripherals0x4001.FFFF0x4001.0000
354I2C Master 00x4002.07FF0x4002.0000
367I2C Slave 00x4002.0FFF0x4002.0800
-Reserved0x4002.3FFF0x4002.2000
139GPIO Port E0x4002.4FFF0x4002.4000
139GPIO Port F0x4002.5FFF0x4002.5000
139GPIO Port G0x4002.6FFF0x4002.6000
139GPIO Port H0x4002.7FFF0x4002.7000
-Reserved0x4002.BFFF0x4002.9000
-Reserved0x4002.FFFF0x4002.E000
185Timer00x4003.0FFF0x4003.0000
185Timer10x4003.1FFF0x4003.1000
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June 26, 200738
LM3S2139 Microcontroller
DescriptionEndStart
Private Peripheral Bus
Instrumentation Trace Macrocell (ITM)0xE000.0FFF0xE000.0000
Data Watchpoint and Trace (DWT)0xE000.1FFF0xE000.1000
Flash Patch and Breakpoint (FPB)0xE000.2FFF0xE000.2000
Reserved0xE000.DFFF0xE000.3000
Nested Vectored Interrupt Controller (NVIC)0xE000.EFFF0xE000.E000
Reserved0xE003.FFFF0xE000.F000
Trace Port Interface Unit (TPIU)0xE004.0FFF0xE004.0000
a. All reserved space returns a bus fault when read or written. b. The unavailable flash will bus fault throughout this range. c. The unavailable SRAM will bus fault throughout this range.
For details on registers, see page ...
185Timer20x4003.2FFF0x4003.2000
-Reserved0x4003.7FFF0x4003.4000
236ADC0x4003.8FFF0x4003.8000
-Reserved0x4003.BFFF0x4003.9000
420Analog Comparators0x4003.CFFF0x4003.C000
-Reserved0x4003.FFFF0x4003.D000
389CAN0 Controller0x4004.0FFF0x4004.0000
-Reserved0x4004.7FFF0x4004.3000
-Reserved0x4004.BFFF0x4004.9000
-Reserved0x400F.BFFF0x4004.C000
113Flash control0x400F.DFFF0x400F.D000
60System control0x400F.EFFF0x400F.E000
-Reserved0x400F.FFFF0x400F.F000
-Reserved0x4011.1FFF0x4011.1000
-Reserved for non bit-banded peripheral space0x41FF.FFFF0x4012.0000
-Bit-banded alias of 0x4000.0000 through 0x400F.FFFF0x43FF.FFFF0x4200.0000
-Reserved for non bit-banded peripheral space0x5E32.FFFF0x4400.0000
-Reserved0x5FFF.FFFF0x5E34.0000
-Reserved for external devices0xDFFF.FFFF0x6000.0000
ARM® Cortex™-M3 Technical Reference Manual
-Reserved0xE004.1FFF0xE004.1000
-Reserved0xE00F.FFFF0xE004.2000
-Reserved for vendor peripherals0xFFFF.FFFF0xE010.0000
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39June 26, 2007

Interrupts

4 Interrupts
The ARM Cortex-M3 processor and the Nested Vectored Interrupt Controller (NVIC) prioritize and handle all exceptions. All exceptions are handled in Handler Mode. The processor state is automatically stored to the stack on an exception, and automatically restored from the stack at the end of the Interrupt Service Routine (ISR). The vector is fetched in parallel to the state saving, which enables efficient interrupt entry. The processor supports tail-chaining, which enables back-to-back interrupts to be performed without the overhead of state saving and restoration.
Table 4-1 on page 40 lists all the exceptions. Software can set eight priority levels on seven of these exceptions (system handlers) as well as on 29 interrupts (listed in Table 4-2 on page 41).
Priorities on the system handlers are set with the NVIC System Handler Priority registers. Interrupts are enabled through the NVIC Interrupt Set Enable register and prioritized with the NVIC Interrupt Priority registers. You can also group priorities by splitting priority levels into pre-emption priorities and subpriorities. All the interrupt registers are described in Chapter 8, “Nested Vectored Interrupt Controller” in the ARM® Cortex™-M3 Technical Reference Manual.
Internally, the highest user-settable priority (0) is treated as fourth priority, after a Reset, NMI, and a Hard Fault. Note that 0 is the default priority for all the settable priorities.
If you assign the same priority level to two or more interrupts, their hardware priority (the lower the position number) determines the order in which the processor activates them. For example, if both GPIO Port A and GPIO Port B are priority level 1, then GPIO Port A has higher priority.
See Chapter 5, “Exceptions” and Chapter 8, “Nested Vectored Interrupt Controller” in the ARM® Cortex™-M3 Technical Reference Manual for more information on exceptions and interrupts.
Note: In Table 4-2 on page 41 interrupts not listed are reserved.
Table 4-1. Exception Types
a
PositionException Type
-3 (highest)1Reset
Interrupt (NMI)
settable4Memory Management
settable5Bus Fault
settable6Usage Fault
DescriptionPriority
Stack top is loaded from first entry of vector table on reset.-0-
Invoked on power up and warm reset. On first instruction, drops to lowest priority (and then is called the base level of activation). This is asynchronous.
Cannot be stopped or preempted by any exception but reset. This is
-22Non-Maskable asynchronous.
An NMI is only producible by software, using the NVIC Interrupt Control State register.
All classes of Fault, when the fault cannot activate due to priority or the
-13Hard Fault configurable fault handler has been disabled. This is synchronous.
MPU mismatch, including access violation and no match. This is synchronous.
The priority of this exception can be changed.
Pre-fetch fault, memory access fault, and other address/memory related faults. This is synchronous when precise and asynchronous when imprecise.
You can enable or disable this fault.
Usage fault, such as undefined instruction executed or illegal state transition attempt. This is synchronous.
Reserved.-7-10-
System service call with SVC instruction. This is synchronous.settable11SVCall
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June 26, 200740
a
PositionException Type
settable12Debug Monitor
settable14PendSV
Interrupts
above
a. 0 is the default priority for all the settable priorities.
settable16 and
DescriptionPriority
Debug monitor (when not halting). This is synchronous, but only active when enabled. It does not activate if lower priority than the current activation.
Reserved.-13-
Pendable request for system service. This is asynchronous and only pended by software.
System tick timer has fired. This is asynchronous.settable15SysTick
Asserted from outside the ARM Cortex-M3 core and fed through the NVIC (prioritized). These are all asynchronous. Table 4-2 on page 41 lists the interrupts on the LM3S2139 controller.
Table 4-2. Interrupts
DescriptionInterrupt (Bit in Interrupt Registers)
GPIO Port A0
GPIO Port B1
GPIO Port C2
GPIO Port D3
GPIO Port E4
UART05
UART16
SSI07
I2C08
ADC Sequence 014
ADC Sequence 115
ADC Sequence 216
ADC Sequence 317
Watchdog timer18
Timer0 A19
Timer0 B20
Timer1 A21
Timer1 B22
Timer2 A23
Timer2 B24
Analog Comparator 025
Analog Comparator 126
Analog Comparator 227
System Control28
Flash Control29
GPIO Port F30
GPIO Port G31
GPIO Port H32
CAN039
Reserved44-47
LM3S2139 Microcontroller
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41June 26, 2007

JTAG Interface

5 JTAG Interface
The Joint Test Action Group (JTAG) port is an IEEE standard that defines a Test Access Port and Boundary Scan Architecture for digital integrated circuits and provides a standardized serial interface for controlling the associated test logic. The TAP, Instruction Register (IR), and Data Registers (DR) can be used to test the interconnections of assembled printed circuit boards and obtain manufacturing information on the components. The JTAG Port also provides a means of accessing and controlling design-for-test features such as I/O pin observation and control, scan testing, and debugging.
The JTAG port is comprised of the standard five pins: TRST, TCK, TMS, TDI, and TDO. Data is transmitted serially into the controller on TDI and out of the controller on TDO. The interpretation of this data is dependent on the current state of the TAP controller. For detailed information on the operation of the JTAG port and TAP controller, please refer to the IEEE Standard 1149.1-Test Access Port and Boundary-Scan Architecture.
The Luminary Micro JTAG controller works with the ARM JTAG controller built into the Cortex-M3 core. This is implemented by multiplexing the TDO outputs from both JTAG controllers. ARM JTAG instructions select the ARM TDO output while Luminary Micro JTAG instructions select the Luminary Micro TDO outputs. The multiplexer is controlled by the Luminary Micro JTAG controller, which has comprehensive programming for the ARM, LMI, and unimplemented JTAG instructions.
The JTAG module has the following features:
IEEE 1149.1-1990 compatible Test Access Port (TAP) controller
Four-bit Instruction Register (IR) chain for storing JTAG instructions
IEEE standard instructions:
BYPASS instruction
IDCODE instruction
SAMPLE/PRELOAD instruction
EXTEST instruction
INTEST instruction
ARM additional instructions:
APACC instruction
DPACC instruction
ABORT instruction
Integrated ARM Serial Wire Debug (SWD)
See the ARM® Cortex™-M3 Technical Reference Manual for more information on the ARM JTAG controller.
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Preliminary

5.1 Block Diagram

Instruction Register(IR)
TAP Controller
BYPASS Data Register
Boundary Scan Data Register
IDCODE Data Register
ABORT Data Register
DPACC Data Register
APACC Data Register
TRST
TCK TMS
TDI
TDO
Cortex-M3 Debug Port
Figure 5-1. JTAG Module Block Diagram
LM3S2139 Microcontroller

5.2 Functional Description

A high-level conceptual drawing of the JTAG module is shown in Figure 5-1 on page 43. The JTAG module is composed of the Test Access Port (TAP) controller and serial shift chains with parallel update registers. The TAP controller is a simple state machine controlled by the TRST, TCK and TMS inputs. The current state of the TAP controller depends on the current value of TRST and the sequence of values captured on TMS at the rising edge of TCK. The TAP controller determines when the serial shift chains capture new data, shift data from TDI towards TDO, and update the parallel load registers. The current state of the TAP controller also determines whether the Instruction Register (IR) chain or one of the Data Register (DR) chains is being accessed.
The serial shift chains with parallel load registers are comprised of a single Instruction Register (IR) chain and multiple Data Register (DR) chains. The current instruction loaded in the parallel load register determines which DR chain is captured, shifted, or updated during the sequencing of the TAP controller.
Some instructions, like EXTEST and INTEST, operate on data currently in a DR chain and do not capture, shift, or update any of the chains. Instructions that are not implemented decode to the BYPASS instruction to ensure that the serial path between TDI and TDO is always connected (see Table 5-2 on page 49 for a list of implemented instructions).
See “JTAG and Boundary Scan” on page 455 for JTAG timing diagrams.
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JTAG Interface

5.2.1 JTAG Interface Pins

The JTAG interface consists of five standard pins: TRST, TCK, TMS, TDI, and TDO. These pins and their associated reset state are given in Table 5-1 on page 44. Detailed information on each pin follows.
Table 5-1. JTAG Port Pins Reset State
5.2.1.1 Test Reset Input (TRST)
The TRST pin is an asynchronous active Low input signal for initializing and resetting the JTAG TAP controller and associated JTAG circuitry. When TRST is asserted, the TAP controller resets to the Test-Logic-Reset state and remains there while TRST is asserted. When the TAP controller enters the Test-Logic-Reset state, the JTAG Instruction Register (IR) resets to the default instruction, IDCODE.
Drive ValueDrive StrengthInternal Pull-DownInternal Pull-UpData DirectionPin Name
N/AN/ADisabledEnabledInputTRST N/AN/ADisabledEnabledInputTCK N/AN/ADisabledEnabledInputTMS N/AN/ADisabledEnabledInputTDI
High-Z2-mA driverDisabledEnabledOutputTDO
By default, the internal pull-up resistor on the TRST pin is enabled after reset. Changes to the pull-up resistor settings on GPIO Port B should ensure that the internal pull-up resistor remains enabled on PB7/TRST; otherwise JTAG communication could be lost.
5.2.1.2 Test Clock Input (TCK)
The TCK pin is the clock for the JTAG module. This clock is provided so the test logic can operate independently of any other system clocks. In addition, it ensures that multiple JTAG TAP controllers that are daisy-chained together can synchronously communicate serial test data between components. During normal operation, TCK is driven by a free-running clock with a nominal 50% duty cycle. When necessary, TCK can be stopped at 0 or 1 for extended periods of time. While TCK is stopped at 0 or 1, the state of the TAP controller does not change and data in the JTAG Instruction and Data Registers is not lost.
By default, the internal pull-up resistor on the TCK pin is enabled after reset. This assures that no clocking occurs if the pin is not driven from an external source. The internal pull-up and pull-down resistors can be turned off to save internal power as long as the TCK pin is constantly being driven by an external source.
5.2.1.3 Test Mode Select (TMS)
The TMS pin selects the next state of the JTAG TAP controller. TMS is sampled on the rising edge of TCK. Depending on the current TAP state and the sampled value of TMS, the next state is entered. Because the TMS pin is sampled on the rising edge of TCK, the IEEE Standard 1149.1 expects the value on TMS to change on the falling edge of TCK.
Holding TMS high for five consecutive TCK cycles drives the TAP controller state machine to the Test-Logic-Reset state. When the TAP controller enters the Test-Logic-Reset state, the JTAG Instruction Register (IR) resets to the default instruction, IDCODE. Therefore, this sequence can be used as a reset mechanism, similar to asserting TRST. The JTAG Test Access Port state machine can be seen in its entirety in Figure 5-2 on page 46.
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June 26, 200744
By default, the internal pull-up resistor on the TMS pin is enabled after reset. Changes to the pull-up resistor settings on GPIO Port C should ensure that the internal pull-up resistor remains enabled on PC1/TMS; otherwise JTAG communication could be lost.
5.2.1.4 Test Data Input (TDI)
The TDI pin provides a stream of serial information to the IR chain and the DR chains. TDI is sampled on the rising edge of TCK and, depending on the current TAP state and the current instruction, presents this data to the proper shift register chain. Because the TDI pin is sampled on the rising edge of TCK, the IEEE Standard 1149.1 expects the value on TDI to change on the falling edge of TCK.
By default, the internal pull-up resistor on the TDI pin is enabled after reset. Changes to the pull-up resistor settings on GPIO Port C should ensure that the internal pull-up resistor remains enabled on PC2/TDI; otherwise JTAG communication could be lost.
5.2.1.5 Test Data Output (TDO)
The TDO pin provides an output stream of serial information from the IR chain or the DR chains. The value of TDO depends on the current TAP state, the current instruction, and the data in the chain being accessed. In order to save power when the JTAG port is not being used, the TDO pin is placed in an inactive drive state when not actively shifting out data. Because TDO can be connected to the TDI of another controller in a daisy-chain configuration, the IEEE Standard 1149.1 expects the value on TDO to change on the falling edge of TCK.
LM3S2139 Microcontroller
By default, the internal pull-up resistor on the TDO pin is enabled after reset. This assures that the pin remains at a constant logic level when the JTAG port is not being used. The internal pull-up and pull-down resistors can be turned off to save internal power if a High-Z output value is acceptable during certain TAP controller states.

5.2.2 JTAG TAP Controller

The JTAG TAP controller state machine is shown in Figure 5-2 on page 46. The TAP controller state machine is reset to the Test-Logic-Reset state on the assertion of a Power-On-Reset (POR) or the assertion of TRST. Asserting the correct sequence on the TMS pin allows the JTAG module to shift in new instructions, shift in data, or idle during extended testing sequences. For detailed information on the function of the TAP controller and the operations that occur in each state, please refer to IEEE Standard 1149.1.
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45June 26, 2007
Test Logic Reset
Run Test Idle Select DR Scan Select IR Scan
Capture DR Capture IR
Shift DR Shift IR
Exit 1 DR Exit 1 IR
Exit 2 DR Exit 2 IR
Pause DR Pause IR
Update DR Update IR
1 11
1 1
1
1 1
1 1
1 1
1 1
1 10 0
00
00
0 0
0 0
0 0
00
0
0
JTAG Interface
Figure 5-2. Test Access Port State Machine

5.2.3 Shift Registers

The Shift Registers consist of a serial shift register chain and a parallel load register. The serial shift register chain samples specific information during the TAP controller’s CAPTURE states and allows this information to be shifted out of TDO during the TAP controller’s SHIFT states. While the sampled data is being shifted out of the chain on TDO, new data is being shifted into the serial shift register on TDI. This new data is stored in the parallel load register during the TAP controller’s UPDATE states. Each of the shift registers is discussed in detail in “Register Descriptions” on page 49.

5.2.4 Operational Considerations

There are certain operational considerations when using the JTAG module. Because the JTAG pins can be programmed to be GPIOs, board configuration and reset conditions on these pins must be considered. In addition, because the JTAG module has integrated ARM Serial Wire Debug, the method for switching between these two operational modes is described below.
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June 26, 200746
5.2.4.1 GPIO Functionality
When the controller is reset with either a POR or RST, the JTAG/SWD port pins default to their JTAG/SWD configurations. The default configuration includes enabling digital functionality (setting GPIODEN to 1), enabling the pull-up resistors (setting GPIOPUR to 1), and enabling the alternate hardware function (setting GPIOAFSEL to 1) for the PB7 and PC[3:0] JTAG/SWD pins.
It is possible for software to configure these pins as GPIOs after reset by writing 0s to PB7 and PC[3:0] in the GPIOAFSEL register. If the user does not require the JTAG/SWD port for debugging or board-level testing, this provides five more GPIOs for use in the design.
Caution – If the JTAG pins are used as GPIOs in a design, PB7 and PC2 cannot have external pull-down resistors connected to both of them at the same time. If both pins are pulled Low during reset, the controller has unpredictable behavior. If this happens, remove one or both of the pull-down resistors, and apply RST or power-cycle the part.
In addition, it is possible to create a software sequence that prevents the debugger from connecting to the Stellaris®microcontroller. If the program code loaded into ash immediately changes the JTAG pins to their GPIO functionality, the debugger may not have enough time to connect and halt the controller before the JTAG pin functionality switches. This may lock the debugger out of the part. This can be avoided with a software routine that restores JTAG functionality based on an external or software trigger.
LM3S2139 Microcontroller
The commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. Writes to protected bits of the GPIO Alternate Function Select (GPIOAFSEL) register (see page 149) are not committed to storage unless the GPIO Lock (GPIOLOCK) register (see page 159) has been unlocked and the appropriate bits of the GPIO Commit (GPIOCR) register (see page 160) have been set to 1.
Recovering a "Locked" Device
If software configures any of the JTAG/SWD pins as GPIO and loses the ability to communicate with the debugger, there is a debug sequence that can be used to recover the device. Performing a total of ten JTAG-to-SWD and SWD-to-JTAG switch sequences while holding the device in reset mass erases the flash memory. The sequence to recover the device is:
1. Assert and hold the RST signal.
2. Perform the JTAG-to-SWD switch sequence.
3. Perform the SWD-to-JTAG switch sequence.
4. Perform the JTAG-to-SWD switch sequence.
5. Perform the SWD-to-JTAG switch sequence.
6. Perform the JTAG-to-SWD switch sequence.
7. Perform the SWD-to-JTAG switch sequence.
8. Perform the JTAG-to-SWD switch sequence.
9. Perform the SWD-to-JTAG switch sequence.
10. Perform the JTAG-to-SWD switch sequence.
11. Perform the SWD-to-JTAG switch sequence.
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47June 26, 2007
JTAG Interface
12. Release the RST signal.
The JTAG-to-SWD and SWD-to-JTAG switch sequences are described in “ARM Serial Wire Debug (SWD)” on page 48. When performing switch sequences for the purpose of recovering the debug capabilities of the device, only steps 1 and 2 of the switch sequence need to be performed.
5.2.4.2 ARM Serial Wire Debug (SWD)
In order to seamlessly integrate the ARM Serial Wire Debug (SWD) functionality, a serial-wire debugger must be able to connect to the Cortex-M3 core without having to perform, or have any knowledge of, JTAG cycles. This is accomplished with a SWD preamble that is issued before the SWD session begins.
The preamble used to enable the SWD interface of the SWJ-DP module starts with the TAP controller in the Test-Logic-Reset state. From here, the preamble sequences the TAP controller through the following states: Run Test Idle, Select DR, Select IR, Test Logic Reset, Test Logic Reset, Run Test Idle, Run Test Idle, Select DR, Select IR, Test Logic Reset, Test Logic Reset, Run Test Idle, Run Test Idle, Select DR, Select IR, and Test Logic Reset states.
Stepping through this sequences of the TAP state machine enables the SWD interface and disables the JTAG interface. For more information on this operation and the SWD interface, see the ARM® Cortex™-M3 Technical Reference Manual and the ARM® CoreSight Technical Reference Manual.
Because this sequence is a valid series of JTAG operations that could be issued, the ARM JTAG TAP controller is not fully compliant to the IEEE Standard 1149.1. This is the only instance where the ARM JTAG TAP controller does not meet full compliance with the specification. Due to the low probability of this sequence occurring during normal operation of the TAP controller, it should not affect normal performance of the JTAG interface.
JTAG-to-SWD Switching
To switch the operating mode of the Debug Access Port (DAP) from JTAG to SWD mode, the external debug hardware must send a switch sequence to the device. The 16-bit switch sequence for switching to SWD mode is defined as b1110011110011110, transmitted LSB first. This can also be represented as 16'hE79E when transmitted LSB first. The complete switch sequence should consist of the following transactions on the TCK/SWCLK and TMS/SWDIO signals:
1. Send at least 50 TCK/SWCLK cycles with TMS/SWDIO set to 1. This ensures that both JTAG and
SWD are in their reset/idle states.
2. Send the 16-bit JTAG-to-SWD switch sequence, 16'hE79E.
3. Send at least 50 TCK/SWCLK cycles with TMS/SWDIO set to 1. This ensures that if SWJ-DP was
already in SWD mode, before sending the switch sequence, the SWD goes into the line reset state.
SWD-to-JTAG Switching
To switch the operating mode of the Debug Access Port (DAP) from SWD to JTAG mode, the external debug hardware must send a switch sequence to the device. The 16-bit switch sequence for switching to JTAG mode is defined as b1110011110011110, transmitted LSB first. This can also be represented as 16'hE73C when transmitted LSB first. The complete switch sequence should consist of the following transactions on the TCK/SWCLK and TMS/SWDIO signals:
1. Send at least 50 TCK/SWCLK cycles with TMS/SWDIO set to 1. This ensures that both JTAG and
SWD are in their reset/idle states.
June 26, 200748
Preliminary
2. Send the 16-bit SWD-to-JTAG switch sequence, 16'hE73C.
3. Send at least 5 TCK/SWCLK cycles with TMS/SWDIO set to 1. This ensures that if SWJ-DP was
already in JTAG mode, before sending the switch sequence, the JTAG goes into the Test Logic Reset state.

5.3 Initialization and Configuration

After a Power-On-Reset or an external reset (RST), the JTAG pins are automatically configured for JTAG communication. No user-defined initialization or configuration is needed. However, if the user application changes these pins to their GPIO function, they must be configured back to their JTAG functionality before JTAG communication can be restored. This is done by enabling the five JTAG pins (PB7 and PC[3:0]) for their alternate function using the GPIOAFSEL register.

5.4 Register Descriptions

There are no APB-accessible registers in the JTAG TAP Controller or Shift Register chains. The registers within the JTAG controller are all accessed serially through the TAP Controller. The registers can be broken down into two main categories: Instruction Registers and Data Registers.

5.4.1 Instruction Register (IR)

LM3S2139 Microcontroller
The JTAG TAP Instruction Register (IR) is a four-bit serial scan chain with a parallel load register connected between the JTAG TDI and TDO pins. When the TAP Controller is placed in the correct states, bits can be shifted into the Instruction Register. Once these bits have been shifted into the chain and updated, they are interpreted as the current instruction. The decode of the Instruction Register bits is shown in Table 5-2 on page 49. A detailed explanation of each instruction, along with its associated Data Register, follows.
Table 5-2. JTAG Instruction Register Commands
DescriptionInstructionIR[3:0]
EXTEST0000
INTEST0001
SAMPLE / PRELOAD0010
IDCODE1110
Drives the values preloaded into the Boundary Scan Chain by the SAMPLE/PRELOAD instruction onto the pads.
Drives the values preloaded into the Boundary Scan Chain by the SAMPLE/PRELOAD instruction into the controller.
Captures the current I/O values and shifts the sampled values out of the Boundary Scan Chain while new preload data is shifted in.
Shifts data into the ARM Debug Port Abort Register.ABORT1000
Shifts data into and out of the ARM DP Access Register.DPACC1010
Shifts data into and out of the ARM AC Access Register.APACC1011
Loads manufacturing information defined by the IEEE Standard 1149.1 into the IDCODE chain and shifts it out.
Connects TDI to TDO through a single Shift Register chain.BYPASS1111 Defaults to the BYPASS instruction to ensure that TDI is always connected to TDO.ReservedAll Others
5.4.1.1 EXTEST Instruction
The EXTEST instruction does not have an associated Data Register chain. The EXTEST instruction uses the data that has been preloaded into the Boundary Scan Data Register using the SAMPLE/PRELOAD instruction. When the EXTEST instruction is present in the Instruction Register, the preloaded data in the Boundary Scan Data Register associated with the outputs and output enables are used to drive the GPIO pads rather than the signals coming from the core. This allows
49June 26, 2007
Preliminary
JTAG Interface
tests to be developed that drive known values out of the controller, which can be used to verify connectivity.
5.4.1.2 INTEST Instruction
The INTEST instruction does not have an associated Data Register chain. The INTEST instruction uses the data that has been preloaded into the Boundary Scan Data Register using the SAMPLE/PRELOAD instruction. When the INTEST instruction is present in the Instruction Register, the preloaded data in the Boundary Scan Data Register associated with the inputs are used to drive the signals going into the core rather than the signals coming from the GPIO pads. This allows tests to be developed that drive known values into the controller, which can be used for testing. It is important to note that although the RST input pin is on the Boundary Scan Data Register chain, it is only observable.
5.4.1.3 SAMPLE/PRELOAD Instruction
The SAMPLE/PRELOAD instruction connects the Boundary Scan Data Register chain between TDI and TDO. This instruction samples the current state of the pad pins for observation and preloads new test data. Each GPIO pad has an associated input, output, and output enable signal. When the TAP controller enters the Capture DR state during this instruction, the input, output, and output-enable signals to each of the GPIO pads are captured. These samples are serially shifted out of TDO while the TAP controller is in the Shift DR state and can be used for observation or comparison in various tests.
While these samples of the inputs, outputs, and output enables are being shifted out of the Boundary Scan Data Register, new data is being shifted into the Boundary Scan Data Register from TDI. Once the new data has been shifted into the Boundary Scan Data Register, the data is saved in the parallel load registers when the TAP controller enters the Update DR state. This update of the parallel load register preloads data into the Boundary Scan Data Register that is associated with each input, output, and output enable. This preloaded data can be used with the EXTEST and INTEST instructions to drive data into or out of the controller. Please see “Boundary Scan Data Register” on page 52 for more information.
5.4.1.4 ABORT Instruction
The ABORT instruction connects the associated ABORT Data Register chain between TDI and TDO. This instruction provides read and write access to the ABORT Register of the ARM Debug
Access Port (DAP). Shifting the proper data into this Data Register clears various error bits or initiates a DAP abort of a previous request. Please see the “ABORT Data Register” on page 52 for more information.
5.4.1.5 DPACC Instruction
The DPACC instruction connects the associated DPACC Data Register chain between TDI and TDO. This instruction provides read and write access to the DPACC Register of the ARM Debug
Access Port (DAP). Shifting the proper data into this register and reading the data output from this register allows read and write access to the ARM debug and status registers. Please see “DPACC Data Register” on page 52 for more information.
5.4.1.6 APACC Instruction
The APACC instruction connects the associated APACC Data Register chain between TDI and TDO. This instruction provides read and write access to the APACC Register of the ARM Debug
Access Port (DAP). Shifting the proper data into this register and reading the data output from this register allows read and write access to internal components and buses through the Debug Port. Please see “APACC Data Register” on page 52 for more information.
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Preliminary
5.4.1.7 IDCODE Instruction
The IDCODE instruction connects the associated IDCODE Data Register chain between TDI and TDO. This instruction provides information on the manufacturer, part number, and version of the
ARM core. This information can be used by testing equipment and debuggers to automatically configure their input and output data streams. IDCODE is the default instruction that is loaded into the JTAG Instruction Register when a power-on-reset (POR) is asserted, TRST is asserted, or the Test-Logic-Reset state is entered. Please see “IDCODE Data Register” on page 51 for more information.
5.4.1.8 BYPASS Instruction
The BYPASS instruction connects the associated BYPASS Data Register chain between TDI and TDO. This instruction is used to create a minimum length serial path between the TDI and TDO ports.
The BYPASS Data Register is a single-bit shift register. This instruction improves test efficiency by allowing components that are not needed for a specific test to be bypassed in the JTAG scan chain by loading them with the BYPASS instruction. Please see “BYPASS Data Register” on page 51 for more information.

5.4.2 Data Registers

The JTAG module contains six Data Registers. These include: IDCODE, BYPASS, Boundary Scan, APACC, DPACC, and ABORT serial Data Register chains. Each of these Data Registers is discussed in the following sections.
LM3S2139 Microcontroller
5.4.2.1 IDCODE Data Register
The format for the 32-bit IDCODE Data Register defined by the IEEE Standard 1149.1 is shown in Figure 5-3 on page 51. The standard requires that every JTAG-compliant device implement either the IDCODE instruction or the BYPASS instruction as the default instruction. The LSB of the IDCODE Data Register is defined to be a 1 to distinguish it from the BYPASS instruction, which has an LSB of 0. This allows auto configuration test tools to determine which instruction is the default instruction.
The major uses of the JTAG port are for manufacturer testing of component assembly, and program development and debug. To facilitate the use of auto-configuration debug tools, the IDCODE instruction outputs a value of 0x3BA00477. This value indicates an ARM Cortex-M3, Version 1 processor. This allows the debuggers to automatically configure themselves to work correctly with the Cortex-M3 during debug.
Figure 5-3. IDCODE Register Format
5.4.2.2 BYPASS Data Register
The format for the 1-bit BYPASS Data Register defined by the IEEE Standard 1149.1 is shown in Figure 5-4 on page 52. The standard requires that every JTAG-compliant device implement either the BYPASS instruction or the IDCODE instruction as the default instruction. The LSB of the BYPASS Data Register is defined to be a 0 to distinguish it from the IDCODE instruction, which has an LSB of 1. This allows auto configuration test tools to determine which instruction is the default instruction.
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51June 26, 2007
O
TDOTDI
O
I
N E
U T
O
O
I
N E
U
T
O
O
I
N E
U T
O
O
I
N E
U
T
I
N
...
...
RSTGPIO PB6 GPIOm GPIO m+1 GPIO n
JTAG Interface
Figure 5-4. BYPASS Register Format
5.4.2.3 Boundary Scan Data Register
The format of the Boundary Scan Data Register is shown in Figure 5-5 on page 52. Each GPIO pin, in a counter-clockwise direction from the JTAG port pins, is included in the Boundary Scan Data Register. Each GPIO pin has three associated digital signals that are included in the chain. These signals are input, output, and output enable, and are arranged in that order as can be seen in the figure. In addition to the GPIO pins, the controller reset pin, RST, is included in the chain. Because the reset pin is always an input, only the input signal is included in the Data Register chain.
When the Boundary Scan Data Register is accessed with the SAMPLE/PRELOAD instruction, the input, output, and output enable from each digital pad are sampled and then shifted out of the chain to be verified. The sampling of these values occurs on the rising edge of TCK in the Capture DR state of the TAP controller. While the sampled data is being shifted out of the Boundary Scan chain in the Shift DR state of the TAP controller, new data can be preloaded into the chain for use with the EXTEST and INTEST instructions. These instructions either force data out of the controller, with the EXTEST instruction, or into the controller, with the INTEST instruction.
Figure 5-5. Boundary Scan Register Format
For detailed information on the order of the input, output, and output enable bits for each of the GPIO ports, please refer to the Stellaris®Family Boundary Scan Description Language (BSDL) files, downloadable from www.luminarymicro.com.
5.4.2.4 APACC Data Register
The format for the 35-bit APACC Data Register defined by ARM is described in the ARM® Cortex™-M3 Technical Reference Manual.
5.4.2.5 DPACC Data Register
The format for the 35-bit DPACC Data Register defined by ARM is described in the ARM® Cortex™-M3 Technical Reference Manual.
5.4.2.6 ABORT Data Register
The format for the 35-bit ABORT Data Register defined by ARM is described in the ARM® Cortex™-M3 Technical Reference Manual.
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Preliminary

6 System Control

System control determines the overall operation of the device. It provides information about the device, controls the clocking to the core and individual peripherals, and handles reset detection and reporting.

6.1 Functional Description

The System Control module provides the following capabilities:
Device identification, see “Device Identification” on page 53
Local control, such as reset (see “Reset Control” on page 53), power (see “Power
Control” on page 56) and clock control (see “Clock Control” on page 56)
System control (Run, Sleep, and Deep-Sleep modes), see “System Control” on page 58

6.1.1 Device Identification

Seven read-only registers provide software with information on the microcontroller, such as version, part number, SRAM size, flash size, and other features. See the DID0, DID1, and DC0-DC4 registers.
LM3S2139 Microcontroller

6.1.2 Reset Control

This section discusses aspects of hardware functions during reset as well as system software requirements following the reset sequence.
6.1.2.1 CMOD0 and CMOD1 Test-Mode Control Pins
Two pins, CMOD0 and CMOD1, are defined for use by Luminary Micro for testing the devices during manufacture. They have no end-user function and should not be used. The CMOD pins should be connected to ground.
6.1.2.2 Reset Sources
The controller has five sources of reset:
1. External reset input pin (RST) assertion, see “RST Pin Assertion” on page 53.
2. Power-on reset (POR), see “Power-On Reset (POR)” on page 54.
3. Internal brown-out (BOR) detector, see “Brown-Out Reset (BOR)” on page 54.
4. Software-initiated reset (with the software reset registers), see “Software Reset” on page 55.
5. A watchdog timer reset condition violation, see “Watchdog Timer Reset” on page 55.
After a reset, the Reset Cause (RESC) register is set with the reset cause. The bits in this register are sticky and maintain their state across multiple reset sequences, except when an internal POR is the cause, and then all the other bits in the RESC register are cleared except for the POR indicator.
6.1.2.3 RST Pin Assertion
The external reset pin (RST) resets the controller. This resets the core and all the peripherals except the JTAG TAP controller (see “JTAG Interface” on page 42). The external reset sequence is as follows:
53June 26, 2007
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R
1
C
1
R
2
RST
Stellaris
D
1
System Control
1. The external reset pin (RST) is asserted and then de-asserted.
2. The internal reset is released and the core loads from memory the initial stack pointer, the initial
program counter, the first instruction designated by the program counter, and begins execution. A few clocks cycles from RST de-assertion to the start of the reset sequence is necessary for synchronization.
The external reset timing is shown in Figure 20-9 on page 457.
6.1.2.4 Power-On Reset (POR)
The Power-On Reset (POR) circuit monitors the power supply voltage (VDD). The POR circuit generates a reset signal to the internal logic when the power supply ramp reaches a threshold value (VTH). If the application only uses the POR circuit, the RSTinput needs to be connected to the power supply (VDD) through a pull-up resistor (1K to 10K Ω).
The device must be operating within the specified operating parameters at the point when the on-chip power-on reset pulse is complete. The 3.3-V power supply to the device must reach 3.0 V within 10 msec of it crossing 2.0 V to guarantee proper operation. For applications that require the use of an external reset to hold the device in reset longer than the internal POR, the RST input may be used with the circuit as shown in Figure 6-1 on page 54.
Figure 6-1. External Circuitry to Extend Reset
The R1and C1components define the power-on delay. The R2resistor mitigates any leakage from the RST input. The diode (D1) discharges C1rapidly when the power supply is turned off.
The Power-On Reset sequence is as follows:
1. The controller waits for the later of external reset (RST) or internal POR to go inactive.
2. The internal reset is released and the core loads from memory the initial stack pointer, the initial
program counter, the first instruction designated by the program counter, and begins execution.
The internal POR is only active on the initial power-up of the controller. The Power-On Reset timing is shown in Figure 20-10 on page 458.
Note: The power-on reset also resets the JTAG controller. An external reset does not.
6.1.2.5 Brown-Out Reset (BOR)
A drop in the input voltage resulting in the assertion of the internal brown-out detector can be used to reset the controller. This is initially disabled and may be enabled by software.
The system provides a brown-out detection circuit that triggers if the power supply (VDD) drops below a brown-out threshold voltage (V
). If a brown-out condition is detected, the system may
BTH
generate a controller interrupt or a system reset.
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June 26, 200754
Brown-out resets are controlled with the Power-On and Brown-Out Reset Control (PBORCTL) register. The BORIOR bit in the PBORCTL register must be set for a brown-out condition to trigger a reset.
The brown-out reset is equivelent to an assertion of the external RST input and the reset is held active until the proper VDDlevel is restored. The RESC register can be examined in the reset interrupt handler to determine if a Brown-Out condition was the cause of the reset, thus allowing software to determine what actions are required to recover.
The internal Brown-Out Reset timing is shown in Figure 20-11 on page 458.
6.1.2.6 Software Reset
Software can generate a reset to the entire system or may reset a specific peripheral.
Peripherals can be individually reset by software via three registers that control reset signals to each peripheral (see the SRCRn registers). If the bit position corresponding to a peripheral is set, the peripheral is reset. The encoding of the reset registers is consistent with the encoding of the clock gating control for peripherals and on-chip functions (see “System Control” on page 58). Writing a bit lane with a value of 1 initiates a reset of the corresponding unit. Note that all reset signals for all clocks of the specified unit are asserted as a result of a software-initiated reset.
The entire system can be reset by software by setting the SYSRESETREQ bit in the Cortex-M3 Application Interrupt and Reset Control register resets the entire system including the core. The software-initiated system reset sequence is as follows:
LM3S2139 Microcontroller
1. A software system reset is initiated by writing the SYSRESETREQ bit in the ARM Cortex-M3
Application Interrupt and Reset Control register.
2. An internal reset is asserted.
3. The internal reset is deasserted and the controller loads from memory the initial stack pointer,
the initial program counter, and the first instruction designated by the program counter, and then begins execution.
The software-initiated system reset timing is shown in Figure 20-12 on page 458.
6.1.2.7 Watchdog Timer Reset
The watchdog timer module's function is to prevent system hangs. The watchdog timer can be configured to generate an interrupt to the controller on its first time-out, and to generate a reset signal on its second time-out.
After the first time-out event, the 32-bit counter is reloaded with the value of the Watchdog Timer Load (WDTLOAD) register, and the timer resumes counting down from that value. If the timer counts down to its zero state again before the first time-out interrupt is cleared, and the reset signal has been enabled, the watchdog timer asserts its reset signal to the system. The watchdog timer reset sequence is as follows:
1. The watchdog timer times out for the second time without being serviced.
2. An internal reset is asserted.
3. The internal reset is released and the controller loads from memory the initial stack pointer, the
initial program counter, the first instruction designated by the program counter, and begins execution.
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System Control
The watchdog reset timing is shown in Figure 20-13 on page 458.

6.1.3 Power Control

The Stellaris®microcontroller provides an integrated LDO regulator that may be used to provide power to the majority of the controller's internal logic. The LDO regulator provides software a mechanism to adjust the regulated value, in small increments (VSTEP), over the range of 2.25 V to 2.75 V (inclusive)—or 2.5 V ± 10%. The adjustment is made by changing the value of the VADJ field in the LDO Power Control (LDOPCTL) register.
Note: The use of the LDO is optional. The internal logic may be supplied by the on-chip LDO or
by an external regulator. If the LDO is used, the LDO output pin is connected to the VDD25 pins on the printed circuit board. The LDO requires decoupling capacitors on the printed circuit board. If an external regulator is used, it is strongly recommended that the external regulator supply the controller only and not be shared with other devices on the printed circuit board.

6.1.4 Clock Control

System control determines the control of clocks in this part.
6.1.4.1 Fundamental Clock Sources
There are four clock sources for use in the device:
Internal Oscillator (IOSC): The internal oscillator is an on-chip clock source. It does not require
the use of any external components. The frequency of the internal oscillator is 12 MHz ± 30%. Applications that do not depend on accurate clock sources may use this clock source to reduce system cost. The internal oscillator is the clock source the device uses during and following POR. If the main oscillator is required, software must enable the main oscillator following reset and allow the main oscillator to stabilize before changing the clock reference.
Main Oscillator: The main oscillator provides a frequency-accurate clock source by one of two
means: an external single-ended clock source is connected to the OSC0 input pin, or an external crystal is connected across the OSC0 input and OSC1 output pins. The crystal value allowed depends on whether the main oscillator is used as the clock reference source to the PLL. If so, the crystal must be one of the supported frequencies between 3.579545 MHz through 8.192 MHz (inclusive). If the PLL is not being used, the crystal may be any one of the supported frequencies between 1 MHz and 8.192 MHz. The single-ended clock source range is from DC through the specified speed of the device. The supported crystals are listed in Table 6-3 on page 71.
Internal 30-kHz Oscillator: The internal 30-kHz oscillator is similar to the internal oscillator,
except that it provides an operational frequency of 30 kHz ± 30%. It is intended for use during Deep-Sleep power-saving modes. This power-savings mode benefits from reduced internal switching and also allows the main oscillator to be powered down.
The internal system clock (sysclk), is derived from any of the four sources plus two others: the output of the internal PLL, and the internal oscillator divided by four (3 MHz ± 30%). The frequency of the PLL clock reference must be in the range of 3.579545 MHz to 8.192 MHz (inclusive).
The Run-Mode Clock Configuration (RCC) and Run-Mode Clock Configuration 2 (RCC2) registers provide control for the system clock. The RCC2 register is provided to extend fields that offer additional encodings over the RCC register. When used, the RCC2 register field values are used by the logic over the corresponding field in the RCC register. In particular, RCC2 provides for a larger assortment of clock configuration options.
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Preliminary
6.1.4.2 Crystal Configuration for the Main Oscillator (MOSC)
The main oscillator supports the use of a select number of crystals in the range of 1 MHz through
8.192 MHz. This method allows Luminary Micro to provide the best possible PLL settings.
Table 6-3 on page 71 describes the available crystal choices and default programming values. Software configures the RCC register XTAL field with the crystal number. If the PLL is used in the
design, the XTAL field value is internally translated to the PLL settings.
6.1.4.3 PLL Frequency Configuration
The PLL is disabled by default during power-on reset and is enabled later by software if required. Software configures the PLL input reference clock source, specifies the output divisor to set the system clock frequency, and enables the PLL to drive the output.
If the main oscillator provides the clock reference to the PLL, the translation provided by hardware and used to program the PLL is available for software in the XTAL to PLL Translation (PLLCFG) register (see page 73). The internal translation provides a translation within ± 1% of the targeted PLL VCO frequency.
Table 6-3 on page 71 describes the available crystal choices and default programming of the
PLLCFG register. The crystal number is written into the XTAL field of the Run-Mode Clock Configuration (RCC) register. Any time the XTAL field changes, the new settings are translated
and the internal PLL settings are updated.
LM3S2139 Microcontroller
6.1.4.4 PLL Modes
The PLL has two modes of operation: Normal and Power-Down
Normal: The PLL multiplies the input clock reference and drives the output.
Power-Down: Most of the PLL internal circuitry is disabled and the PLL does not drive the output.
The modes are programmed using the RCC/RCC2 register fields (see page 69 and page 74).
6.1.4.5 PLL Operation
If the PLL configuration is changed, the PLL output frequency is unstable until it reconverges (relocks) to the new setting. The time between the configuration change and relock is T 20-6 on page 451). During this time, the PLL is not usable as a clock reference.
The PLL is changed by one of the following:
Change to the XTAL value in the RCC register—writes of the same value do not cause a relock.
Change in the PLL from Power-Down to Normal mode.
A counter is defined to measure the T oscillator. The range of the main oscillator has been taken into account and the down counter is set to 0x1200 (that is, ~600 μs at an 8.192 MHz external oscillator clock). Hardware is provided to keep the PLL from being used as a system clock until the T changes above. It is the user's responsibility to have a stable clock source (like the main oscillator) before the RCC/RCC2 register is switched to use the PLL.
requirement. The counter is clocked by the main
READY
condition is met after one of the two
READY
READY
(see Table
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57June 26, 2007

System Control

6.1.5 System Control
For power-savings purposes, the RCGCn , SCGCn , and DCGCn registers control the clock gating logic for each peripheral or block in the system while the controller is in Run, Sleep, and Deep-Sleep mode, respectively.
In Run mode, the processor executes code. In Sleep mode, the clock frequency of the active peripherals is unchanged, but the processor is not clocked and therefore no longer executes code. In Deep-Sleep mode, the clock frequency of the active peripherals may change (depending on the Run mode clock configuration) in addition to the processor clock being stopped. An interrupt returns the device to Run mode from one of the sleep modes; the sleep modes are entered on request from the code. Each mode is described in more detail below.
There are four levels of operation for the device defined as:
Run Mode. Run mode provides normal operation of the processor and all of the peripherals that
are currently enabled by the RCGCn registers. The system clock can be any of the available clock sources including the PLL.
Sleep Mode. Sleep mode is entered by the Cortex-M3 core executing a WFI (Wait for
Interrupt) instruction. Any properly configured interrupt event in the system will bring the processor back into Run mode. See the system control NVIC section of the ARM® Cortex™-M3 Technical Reference Manual for more details.
In Sleep mode, the Cortex-M3 processor core and the memory subsystem are not clocked. Peripherals are clocked that are enabled in the SCGCn register when auto-clock gating is enabled (see the RCC register) or the RCGCn register when the auto-clock gating is disabled. The system clock has the same source and frequency as that during Run mode.
Deep-Sleep Mode. Deep-Sleep mode is entered by first writing the Deep Sleep Enable bit in
the ARM Cortex-M3 NVIC system control register and then executing a WFI instruction. Any properly configured interrupt event in the system will bring the processor back into Run mode. See the system control NVIC section of the ARM® Cortex™-M3 Technical Reference Manual for more details.
The Cortex-M3 processor core and the memory subsystem are not clocked. Peripherals are clocked that are enabled in the DCGCn register when auto-clock gating is enabled (see the RCC register) or the RCGCn register when auto-clock gating is disabled. The system clock source is the main oscillator by default or the internal oscillator specified in the DSLPCLKCFG register if one is enabled. When the DSLPCLKCFG register is used, the internal oscillator is powered up, if necessary, and the main oscillator is powered down. If the PLL is running at the time of the WFI instruction, hardware will power the PLL down and override the SYSDIV field of the active RCC/RCC2 register to be /16 or /64, respectively. When the Deep-Sleep exit event occurs, hardware brings the system clock back to the source and frequency it had at the onset of Deep-Sleep mode before enabling the clocks that had been stopped during the Deep-Sleep duration.

6.2 Initialization and Configuration

The PLL is configured using direct register writes to the RCC/RCC2 register. If the RCC2 register is being used, the USERCC2 bit must be set and the appropriate RCC2 bit/field is used. The steps required to successfully change the PLL-based system clock are:
1. Bypass the PLL and system clock divider by setting the BYPASS bit and clearing the USESYS
bit in the RCC register. This configures the system to run off a “raw” clock source (using the
June 26, 200758
Preliminary
main oscillator or internal oscillator) and allows for the new PLL configuration to be validated before switching the system clock to the PLL.
2. Select the crystal value (XTAL) and oscillator source (OSCSRC), and clear the PWRDN bit in
RCC/RCC2. Setting the XTAL field automatically pulls valid PLL configuration data for the
appropriate crystal, and clearing the PWRDN bit powers and enables the PLL and its output.
3. Select the desired system divider (SYSDIV) in RCC/RCC2 and set the USESYS bit in RCC. The
SYSDIV field determines the system frequency for the microcontroller.
4. Wait for the PLL to lock by polling the PLLLRIS bit in the Raw Interrupt Status (RIS) register.
5. Enable use of the PLL by clearing the BYPASS bit in RCC/RCC2.

6.3 Register Map

Table 6-1 on page 59 lists the System Control registers, grouped by function. The offset listed is a hexadecimal increment to the register’s address, relative to the System Control base address of 0x400F.E000.
Note: Spaces in the System Control register space that are not used are reserved for future or
internal use by Luminary Micro, Inc. Software should not modify any reserved memory address.
LM3S2139 Microcontroller
Table 6-1. System Control Register Map
DescriptionResetTypeNameOffset
See
page
61Device Identification 0-RODID00x000
77Device Identification 1-RODID10x004
79Device Capabilities 00x003F.001FRODC00x008
80Device Capabilities 10x0101.71BFRODC10x010
82Device Capabilities 20x0707.1013RODC20x014
84Device Capabilities 30x3F0F.37C0RODC30x018
86Device Capabilities 40x0000.00FFRODC40x01C
63Brown-Out Reset Control0x0000.7FFDR/WPBORCTL0x030
64LDO Power Control0x0000.0000R/WLDOPCTL0x034
105Software Reset Control 00x00000000R/WSRCR00x040
106Software Reset Control 10x00000000R/WSRCR10x044
108Software Reset Control 20x00000000R/WSRCR20x048
65Raw Interrupt Status0x0000.0000RORIS0x050
66Interrupt Mask Control0x0000.0000R/WIMC0x054
Preliminary
67Masked Interrupt Status and Clear0x0000.0000R/W1CMISC0x058
68Reset Cause-R/WRESC0x05C
69Run-Mode Clock Configuration0x07A0.3AD1R/WRCC0x060
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System Control

6.4 Register Descriptions

All addresses given are relative to the System Control base address of 0x400F.E000.
DescriptionResetTypeNameOffset
See
page
73XTAL to PLL Translation-ROPLLCFG0x064
74Run-Mode Clock Configuration 20x0780.2800R/WRCC20x070
87Run Mode Clock Gating Control Register 00x00000040R/WRCGC00x100
93Run Mode Clock Gating Control Register 10x00000000R/WRCGC10x104
99Run Mode Clock Gating Control Register 20x00000000R/WRCGC20x108
89Sleep Mode Clock Gating Control Register 00x00000040R/WSCGC00x110
95Sleep Mode Clock Gating Control Register 10x00000000R/WSCGC10x114
101Sleep Mode Clock Gating Control Register 20x00000000R/WSCGC20x118
91Deep Sleep Mode Clock Gating Control Register 00x00000040R/WDCGC00x120
97Deep Sleep Mode Clock Gating Control Register 10x00000000R/WDCGC10x124
103Deep Sleep Mode Clock Gating Control Register 20x00000000R/WDCGC20x128
76Deep Sleep Clock Configuration0x0780.0000R/WDSLPCLKCFG0x144
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June 26, 200760

Register 1: Device Identification 0 (DID0), offset 0x000

This register identifies the version of the device.
Device Identification 0 (DID0)
Base 0x400F.E000 Offset 0x000 Type RO, reset -
LM3S2139 Microcontroller
16171819202122232425262728293031
CLASSreservedVERreserved
ROROROROROROROROROROROROROROROROType
1000000000001000Reset
0123456789101112131415
MINORMAJOR
ROROROROROROROROROROROROROROROROType
----------------Reset
DescriptionResetTypeNameBit/Field
0ROreserved31
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
1ROVER30:28
DID0 Version
This field defines the DID0 register format version. The version number is numeric. The value of the VER field is encoded as follows:
DescriptionValue
First revision of the DID0 register format, for Stellaris®
1
Fury-class devices.
0ROreserved27:24
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
1ROCLASS23:16
Device Class The CLASS field value identifies the internal design from which all mask
sets are generated for all devices in a particular product line. The CLASS field value is changed for new product lines, for changes in fab process (for example, a remap or shrink), or any case where the MAJOR or MINOR fields require differentiation from prior devices. The value of the CLASS field is encoded as follows (all other encodings are reserved):
DescriptionValue
Stellaris® Sandstorm-class devices.0
Stellaris® Fury-class devices.1
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61June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
-ROMAJOR15:8
-ROMINOR7:0
Major Revision
This field specifies the major revision number of the device. The major revision reflects changes to base layers of the design. The major revision number is indicated in the part number as a letter (A for first revision, B for second, and so on). This field is encoded as follows:
DescriptionValue
Revision A (initial device)0
Revision B (first base layer revision)1
Revision C (second base layer revision)2
and so on.
Minor Revision
This field specifies the minor revision number of the device. The minor revision reflects changes to the metal layers of the design. The MINOR field value is reset when the MAJOR field is changed. This field is numeric and is encoded as follows:
DescriptionValue
Initial device, or a major revision update.0
First metal layer change.1
Second metal layer change.2
and so on.
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June 26, 200762

Register 2: Brown-Out Reset Control (PBORCTL), offset 0x030

This register is responsible for controlling reset conditions after initial power-on reset.
Brown-Out Reset Control (PBORCTL)
Base 0x400F.E000 Offset 0x030 Type R/W, reset 0x0000.7FFD
DescriptionResetTypeNameBit/Field
reserved
LM3S2139 Microcontroller
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
reservedBORIORreserved
ROR/WROROROROROROROROROROROROROROType
0000000000000000Reset
0ROreserved31:2
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WBORIOR1
BOR Interrupt or Reset
This bit controls how a BOR event is signaled to the controller. If set, a reset is signaled. Otherwise, an interrupt is signaled.
0ROreserved0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
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63June 26, 2007
System Control

Register 3: LDO Power Control (LDOPCTL), offset 0x034

The VADJ field in this register adjusts the on-chip output voltage (V
LDO Power Control (LDOPCTL)
Base 0x400F.E000 Offset 0x034 Type R/W, reset 0x0000.0000
).
OUT
16171819202122232425262728293031
reserved
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
VADJreserved
R/WR/WR/WR/WR/WR/WROROROROROROROROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:6
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0x0R/WVADJ5:0
LDO Output Voltage
This field sets the on-chip output voltage. The programming values for the VADJ field are provided in Table 6-2 on page 64.
Table 6-2. VADJ to VOUT
(V)VADJ Value
OUT
OUT
V
(V)VADJ ValueV
OUT
(V)VADJ ValueV
2.350x032.550x1F2.750x1B
2.300x042.500x002.700x1C
2.250x052.450x012.650x1D
Reserved0x06-0x3F2.400x022.600x1E
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June 26, 200764

Register 4: Raw Interrupt Status (RIS), offset 0x050

Central location for system control raw interrupts. These are set and cleared by hardware.
Raw Interrupt Status (RIS)
Base 0x400F.E000 Offset 0x050 Type RO, reset 0x0000.0000
DescriptionResetTypeNameBit/Field
reserved
LM3S2139 Microcontroller
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
reservedBORRISreservedPLLLRISreserved
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0ROreserved31:7
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0ROPLLLRIS6
0ROreserved5:2
PLL Lock Raw Interrupt Status
This bit is set when the PLL T
READY
Timer asserts.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0ROBORRIS1
Brown-Out Reset Raw Interrupt Status
This bit is the raw interrupt status for any brown-out conditions. If set, a brown-out condition is currently active. This is an unregistered signal from the brown-out detection circuit. An interrupt is reported if the BORIM bit in the IMC register is set and the BORIOR bit in the PBORCTL register is cleared.
0ROreserved0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
65June 26, 2007
System Control

Register 5: Interrupt Mask Control (IMC), offset 0x054

Central location for system control interrupt masks.
Interrupt Mask Control (IMC)
Base 0x400F.E000 Offset 0x054 Type R/W, reset 0x0000.0000
DescriptionResetTypeNameBit/Field
reserved
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
reservedBORIMreservedPLLLIMreserved
ROR/WROROROROR/WROROROROROROROROROType
0000000000000000Reset
0ROreserved31:7
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WPLLLIM6
PLL Lock Interrupt Mask
This bit specifies whether a current limit detection is promoted to a controller interrupt. If set, an interrupt is generated if PLLLRIS in RIS is set; otherwise, an interrupt is not generated.
0ROreserved5:2
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WBORIM1
Brown-Out Reset Interrupt Mask
This bit specifies whether a brown-out condition is promoted to a controller interrupt. If set, an interrupt is generated if BORRIS is set; otherwise, an interrupt is not generated.
0ROreserved0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
June 26, 200766

Register 6: Masked Interrupt Status and Clear (MISC), offset 0x058

Central location for system control result of RIS AND IMC to generate an interrupt to the controller. All of the bits are R/W1C and this action also clears the corresponding raw interrupt bit in the RIS register (see page 65).
Masked Interrupt Status and Clear (MISC)
Base 0x400F.E000 Offset 0x058 Type R/W1C, reset 0x0000.0000
DescriptionResetTypeNameBit/Field
reserved
LM3S2139 Microcontroller
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
reservedBORMISreservedPLLLMISreserved
ROR/W1CROROROROR/W1CROROROROROROROROROType
0000000000000000Reset
0ROreserved31:7
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/W1CPLLLMIS6
PLL Lock Masked Interrupt Status
This bit is set when the PLL T
READY
timer asserts. The interrupt is cleared
by writing a 1 to this bit.
0ROreserved5:2
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/W1CBORMIS1
BOR Masked Interrupt Status The BORMIS is simply the BORRIS ANDed with the mask value, BORIM.
0ROreserved0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
67June 26, 2007
System Control

Register 7: Reset Cause (RESC), offset 0x05C

This register is set with the reset cause after reset. The bits in this register are sticky and maintain their state across multiple reset sequences, except when an external reset is the cause, and then all the other bits in the RESC register are cleared.
Reset Cause (RESC)
Base 0x400F.E000 Offset 0x05C Type R/W, reset -
DescriptionResetTypeNameBit/Field
reserved
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
EXTPORBORWDTSWLDOreserved
R/WR/WR/WR/WR/WR/WROROROROROROROROROROType
------0000000000Reset
0ROreserved31:6
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
-R/WLDO5
LDO Reset
When set, indicates the LDO circuit has lost regulation and has generated a reset event.
-R/WSW4
Software Reset
When set, indicates a software reset is the cause of the reset event.
-R/WWDT3
Watchdog Timer Reset
When set, indicates a watchdog reset is the cause of the reset event.
-R/WBOR2
Brown-Out Reset
When set, indicates a brown-out reset is the cause of the reset event.
-R/WPOR1
Power-On Reset
When set, indicates a power-on reset is the cause of the reset event.
-R/WEXT0
External Reset When set, indicates an external reset (RST assertion) is the cause of
the reset event.
Preliminary
June 26, 200768

Register 8: Run-Mode Clock Configuration (RCC), offset 0x060

This register is defined to provide source control and frequency speed.
Run-Mode Clock Configuration (RCC)
Base 0x400F.E000 Offset 0x060 Type R/W, reset 0x07A0.3AD1
LM3S2139 Microcontroller
16171819202122232425262728293031
reservedUSESYSDIVSYSDIVACGreserved
ROROROROROROR/WR/WR/WR/WR/WR/WROROROROType
0000000111100000Reset
0123456789101112131415
MOSCDISIOSCDISreservedOSCSRCXTALreservedBYPASSreservedPWRDNreserved
R/WR/WROROR/WR/WR/WR/WR/WR/WROR/WROR/WROROType
1000101101011110Reset
DescriptionResetTypeNameBit/Field
0x0ROreserved31:28
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WACG27
Auto Clock Gating
This bit specifies whether the system uses the Sleep-Mode Clock
Gating Control (SCGCn) registers and Deep-Sleep-Mode Clock Gating Control (DCGCn) registers if the controller enters a Sleep or
Deep-Sleep mode (respectively). If set, the SCGCn or DCGCn registers are used to control the clocks distributed to the peripherals when the controller is in a sleep mode. Otherwise, the Run-Mode Clock Gating Control (RCGCn) registers are used when the controller enters a sleep mode.
The RCGCn registers are always used to control the clocks in Run mode.
This allows peripherals to consume less power when the controller is in a sleep mode and the peripheral is unused.
Preliminary
69June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0xFR/WSYSDIV26:23
0R/WUSESYSDIV22
System Clock Divisor
Specifies which divisor is used to generate the system clock from the PLL output.
The PLL VCO frequency is 400 MHz.
Frequency (BYPASS=0)Divisor (BYPASS=1)Binary Value
reservedreserved0000-0110
50 MHz/80011
25 MHz/160111
22.22 MHz/181000
20 MHz/201001
18.18 MHz/221010
16.67 MHz/241011
15.38 MHz/261100
14.29 MHz/281101
13.33 MHz/301110
12.5 MHz (default)/321111
When reading the Run-Mode Clock Configuration (RCC) register (see page 69), the SYSDIV value is MINSYSDIV if a lower divider was requested and the PLL is being used. This lower value is allowed to divide a non-PLL source.
Enable System Clock Divider
Use the system clock divider as the source for the system clock. The system clock divider is forced to be used when the PLL is selected as the source.
1ROreserved21:14
1R/WPWRDN13
1ROreserved12
1R/WBYPASS11
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
PLL Power Down
This bit connects to the PLL PWRDN input. The reset value of 1 powers down the PLL.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
PLL Bypass
Chooses whether the system clock is derived from the PLL output or the OSC source. If set, the clock that drives the system is the OSC source. Otherwise, the clock that drives the system is the PLL output clock divided by the system divider.
Note: The ADC must be clocked from the PLL or directly from a
14-MHz to 18-MHz clock source to operate properly. While the ADC works in a 14-18 MHz range, to maintain a 1 M sample/second rate, the ADC must be provided a 16-MHz clock source.
Preliminary
June 26, 200770
LM3S2139 Microcontroller
DescriptionResetTypeNameBit/Field
0ROreserved10
0xBR/WXTAL9:6
0x1R/WOSCSRC5:4
0x0ROreserved3:2
0R/WIOSCDIS1
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Crystal Value
This field specifies the crystal value attached to the main oscillator. The encoding for this field is provided in Table 6-3 on page 71.
Oscillator Source
Picks among the four input sources for the OSC. The values are:
Input SourceValue
Main oscillator (default)00
Internal oscillator (default)01
Internal oscillator / 4 (this is necessary if used as input to PLL)10
reserved11
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Internal Oscillator Disable
0: Internal oscillator (IOSC) is enabled.
1: Internal oscillator is disabled.
1R/WMOSCDIS0
Main Oscillator Disable
0: Main oscillator is enabled.
1: Main oscillator is disabled (default).
Table 6-3. Default Crystal Field Values and PLL Programming
Crystal Number (XTAL Binary Value)
the PLL
3.579545 MHz0100
3.6864 MHz0101
4 MHz0110
4.096 MHz0111
4.9152 MHz1000
5 MHz1001
5.12 MHz1010
6 MHz (reset value)1011
6.144 MHz1100
7.3728 MHz1101
Crystal Frequency (MHz) Using the PLLCrystal Frequency (MHz) Not Using
reserved1.0000000
reserved1.84320001
reserved2.0000010
reserved2.45760011
Preliminary
71June 26, 2007
System Control
Crystal Number (XTAL Binary Value)
Crystal Frequency (MHz) Using the PLLCrystal Frequency (MHz) Not Using
the PLL
8 MHz1110
8.192 MHz1111
Preliminary
June 26, 200772

Register 9: XTAL to PLL Translation (PLLCFG), offset 0x064

This register provides a means of translating external crystal frequencies into the appropriate PLL settings. This register is initialized during the reset sequence and updated anytime that the XTAL field changes in the Run-Mode Clock Configuration (RCC) register (see page 69).
The PLL frequency is calculated using the PLLCFG field values, as follows:
PLLFreq = OSCFreq * F / (R + 1)
XTAL to PLL Translation (PLLCFG)
Base 0x400F.E000 Offset 0x064 Type RO, reset -
reserved
LM3S2139 Microcontroller
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
RFOD
ROROROROROROROROROROROROROROROROType
----------------Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:16
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
-ROOD15:14
PLL OD Value
This field specifies the value supplied to the PLL’s OD input.
-ROF13:5
PLL F Value
This field specifies the value supplied to the PLL’s F input.
-ROR4:0
PLL R Value
This field specifies the value supplied to the PLL’s R input.
Preliminary
73June 26, 2007
System Control

Register 10: Run-Mode Clock Configuration 2 (RCC2), offset 0x070

This register overrides the RCC equivalent register fields when the USERCC2 bit is set. This allows RCC2 to be used to extend the capabilities, while also providing a means to be backward-compatible
to previous parts. The fields within the RCC2 register occupy the same bit positions as they do within the RCC register as LSB-justified.
The SYSDIV2 field is wider so that additional larger divisors are possible. This allows a lower system clock frequency for improved Deep Sleep power consumption.
Run-Mode Clock Configuration 2 (RCC2)
Base 0x400F.E000 Offset 0x070 Type R/W, reset 0x0780.2800
16171819202122232425262728293031
reservedSYSDIV2reservedUSERCC2
ROROROROROROROR/WR/WR/WR/WR/WR/WROROR/WType
0000000111100000Reset
0123456789101112131415
reservedOSCSRC2reservedBYPASS2reservedPWRDN2reserved
ROROROROR/WR/WR/WROROROROR/WROR/WROROType
0000000000010100Reset
DescriptionResetTypeNameBit/Field
0R/WUSERCC231
0ROreserved30:29
0x0FR/WSYSDIV228:23
0ROreserved22:14
1R/WPWRDN213
Use RCC2
When set, overrides the RCC register fields.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
System Clock Divisor
Specifies which divisor is used to generate the system clock from the PLL output.
The PLL VCO frequency is 400 MHz. This field is wider than the RCC register SYSDIV field in order to provide
additional divisor values. This permits the system clock to be run at much lower frequencies during Deep Sleep mode. For example, where the RCC register SYSDIV encoding of 111 provides /16, the RCC2 register SYSDIV2 encoding of 111111 provides /64.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Power-Down PLL
When set, powers down the PLL.
0ROreserved12
1R/WBYPASS211
Preliminary
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Bypass PLL
When set, bypasses the PLL for the clock source.
June 26, 200774
LM3S2139 Microcontroller
DescriptionResetTypeNameBit/Field
0ROreserved10:7
0R/WOSCSRC26:4
0ROreserved3:0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
System Clock Source
DescriptionValueName
Main oscillator0MOSC
Internal oscillator1IOSC
Internal oscillator / 42IOSC/4
30 kHz internal oscillator330kHz
32 kHz external oscillator732kHz
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
75June 26, 2007
System Control

Register 11: Deep Sleep Clock Configuration (DSLPCLKCFG), offset 0x144

This register provides configuration information for the hardware control of Deep Sleep Mode.
Deep Sleep Clock Configuration (DSLPCLKCFG)
Base 0x400F.E000 Offset 0x144 Type R/W, reset 0x0780.0000
16171819202122232425262728293031
reservedDSDIVORIDEreserved
ROROROROROROROR/WR/WR/WR/WR/WR/WROROROType
0000000111100000Reset
0123456789101112131415
reservedDSOSCSRCreserved
ROROROROR/WR/WR/WROROROROROROROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:29
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0x0FR/WDSDIVORIDE28:23
Divider Field Override
6-bit system divider field to override when Deep-Sleep occurs with PLL running.
0ROreserved22:7
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WDSOSCSRC6:4
Clock Source
When set, forces IOSC to be clock source during Deep Sleep mode.
DescriptionValueName
No override to the oscillator clock source is done0NOORIDE
Use internal 12 MHz oscillator as source1IOSC
Use 30 kHz internal oscillator330kHz
Use 32 kHz external oscillator732kHz
0ROreserved3:0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
June 26, 200776

Register 12: Device Identification 1 (DID1), offset 0x004

This register identifies the device family, part number, temperature range, pin count, and package type.
Device Identification 1 (DID1)
Base 0x400F.E000 Offset 0x004 Type RO, reset -
LM3S2139 Microcontroller
16171819202122232425262728293031
PARTNOFAMVER
ROROROROROROROROROROROROROROROROType
0010000100001000Reset
0123456789101112131415
QUALROHSPKGTEMPreservedPINCOUNT
ROROROROROROROROROROROROROROROROType
--11010000000010Reset
DescriptionResetTypeNameBit/Field
0x1ROVER31:28
DID1 Version
This field defines the DID1 register format version. The version number is numeric. The value of the VER field is encoded as follows (all other encodings are reserved):
DescriptionValue
First revision of the DID1 register format, indicating a Stellaris
0x1
Fury-class device.
0x0ROFAM27:24
Family
This field provides the family identification of the device within the Luminary Micro product portfolio. The value is encoded as follows (all other encodings are reserved):
DescriptionValue
Stellaris family of microcontollers, that is, all devices with
0x0
external part numbers starting with LM3S.
0x84ROPARTNO23:16
Part Number
This field provides the part number of the device within the family. The value is encoded as follows (all other encodings are reserved):
DescriptionValue
LM3S21390x84
0x2ROPINCOUNT15:13
Preliminary
Package Pin Count
This field specifies the number of pins on the device package. The value is encoded as follows (all other encodings are reserved):
DescriptionValue
100-pin package0x2
77June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0ROreserved12:8
0x1ROTEMP7:5
0x1ROPKG4:3
1ROROHS2
-ROQUAL1:0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Temperature Range
This field specifies the temperature rating of the device. The value is encoded as follows (all other encodings are reserved):
DescriptionValue
Industrial temperature range (-40°C to 85°C)0x1
Package Type
This field specifies the package type. The value is encoded as follows (all other encodings are reserved):
DescriptionValue
LQFP package0x1
RoHS-Compliance
This bit specifies whether the device is RoHS-compliant. A 1 indicates the part is RoHS-compliant.
Qualification Status
This field specifies the qualification status of the device. The value is encoded as follows (all other encodings are reserved):
DescriptionValue
Engineering Sample (unqualified)0x0
Pilot Production (unqualified)0x1
Fully Qualified0x2
Preliminary
June 26, 200778

Register 13: Device Capabilities 0 (DC0), offset 0x008

This register is predefined by the part and can be used to verify features.
Device Capabilities 0 (DC0)
Base 0x400F.E000 Offset 0x008 Type RO, reset 0x003F.001F
SRAMSZ
FLASHSZ
DescriptionResetTypeNameBit/Field
LM3S2139 Microcontroller
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
1111110000000000Reset
0123456789101112131415
ROROROROROROROROROROROROROROROROType
1111100000000000Reset
0x003FROSRAMSZ31:16
SRAM Size
Indicates the size of the on-chip SRAM memory.
DescriptionValue
16 KB of SRAM0x003F
0x001FROFLASHSZ15:0
Flash Size
Indicates the size of the on-chip flash memory.
DescriptionValue
64 KB of Flash0x001F
Preliminary
79June 26, 2007
System Control

Register 14: Device Capabilities 1 (DC1), offset 0x010

This register is predefined by the part and can be used to verify features. The PWM, SARADC0, MAXADCSPD, WDT, SWO, SWD, and JTAG bits mask the RCGC0, SCGC0, and DCGC0 registers.
Other bits are passed as 0. MAXADCSPD is clipped to the maximum value specified in DC1.
Device Capabilities 1 (DC1)
Base 0x400F.E000 Offset 0x010 Type RO, reset 0x0101.71BF
16171819202122232425262728293031
SARADC0reservedCAN0reserved
ROROROROROROROROROROROROROROROROType
1000000010000000Reset
0123456789101112131415
JTAGSWDSWOWDTPLLTEMPSNSreservedMPUMAXADCSPDSYSDIV
ROROROROROROROROROROROROROROROROType
1111110110001110Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:25
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
1ROCAN024
CAN Module 0 Present
When set, indicates that CAN unit 0 is present.
0ROreserved23:17
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
1ROSARADC016
ADC Module Present. When set, indicates that the ADC module is present.
0x7ROSYSDIV15:12
System Clock Divider. Minimum 4-bit divider value for system clock. The reset value is hardware-dependent. See the RCC register for how to change the system clock divisor using the SYSDIV bit.
DescriptionValue
Specifies a 25-MHz clock with a PLL divider of 8.0x7
0x1ROMAXADCSPD11:8
Max ADC Speed. This field indicates the maximum rate at which the ADC samples data.
DescriptionValue
250K samples/second0x1
1ROMPU7
0ROreserved6
Preliminary
MPU Present. When set, indicates that the Cortex-M3 Memory Protection Unit (MPU) module is present. See the ARM Cortex-M3 Technical Reference Manual for details on the MPU.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
June 26, 200780
LM3S2139 Microcontroller
DescriptionResetTypeNameBit/Field
1ROTEMPSNS5
1ROPLL4
1ROWDT3
1ROSWO2
1ROSWD1
1ROJTAG0
Temp Sensor Present. When set, indicates that the on-chip temperature sensor is present.
PLL Present. When set, indicates that the on-chip Phase Locked Loop (PLL) is present.
Watchdog Timer Present. When set, indicates that a watchdog timer is present.
SWO Trace Port Present. When set, indicates that the Serial Wire Output (SWO) trace port is present.
SWD Present. When set, indicates that the Serial Wire Debugger (SWD) is present.
JTAG Present. When set, indicates that the JTAG debugger interface is present.
Preliminary
81June 26, 2007
System Control

Register 15: Device Capabilities 2 (DC2), offset 0x014

This register is predefined by the part and can be used to verify features.
Device Capabilities 2 (DC2)
Base 0x400F.E000 Offset 0x014 Type RO, reset 0x0707.1013
16171819202122232425262728293031
TIMER0TIMER1TIMER2reservedCOMP0COMP1COMP2reserved
ROROROROROROROROROROROROROROROROType
1110000011100000Reset
0123456789101112131415
UART0UART1reservedSSI0reservedI2C0reserved
ROROROROROROROROROROROROROROROROType
1100100000001000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:27
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
1ROCOMP226
Analog Comparator 2 Present. When set, indicates that analog comparator 2 is present.
1ROCOMP125
Analog Comparator 1 Present. When set, indicates that analog comparator 1 is present.
1ROCOMP024
Analog Comparator 0 Present. When set, indicates that analog comparator 0 is present.
0ROreserved23:19
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
1ROTIMER218
Timer 2 Present. When set, indicates that General-Purpose Timer module 2 is present.
1ROTIMER117
Timer 1 Present. When set, indicates that General-Purpose Timer module 1 is present.
1ROTIMER016
Timer 0 Present. When set, indicates that General-Purpose Timer module 0 is present.
0ROreserved15:13
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0ROreserved11:5
0ROreserved3:2
Preliminary
I2C Module 0 Present. When set, indicates that I2C module 0 is present.1ROI2C012
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
SSI0 Present. When set, indicates that SSI module 0 is present.1ROSSI04
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
June 26, 200782
LM3S2139 Microcontroller
DescriptionResetTypeNameBit/Field
UART1 Present. When set, indicates that UART module 1 is present.1ROUART11
UART0 Present. When set, indicates that UART module 0 is present.1ROUART00
Preliminary
83June 26, 2007
System Control

Register 16: Device Capabilities 3 (DC3), offset 0x018

This register is predefined by the part and can be used to verify features.
Device Capabilities 3 (DC3)
Base 0x400F.E000 Offset 0x018 Type RO, reset 0x3F0F.37C0
16171819202122232425262728293031
ADC0ADC1ADC2ADC3reservedCCP0CCP1CCP2CCP3CCP4CCP5reserved
ROROROROROROROROROROROROROROROROType
1111000011111100Reset
0123456789101112131415
reservedC0MINUSC0PLUSC0OC1MINUSC1PLUSreservedC2MINUSC2PLUSreserved
ROROROROROROROROROROROROROROROROType
0000001111101100Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:30
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
1ROCCP529
CCP5 Pin Present. When set, indicates that Capture/Compare/PWM pin 5 is present.
1ROCCP428
CCP4 Pin Present. When set, indicates that Capture/Compare/PWM pin 4 is present.
1ROCCP327
CCP3 Pin Present. When set, indicates that Capture/Compare/PWM pin 3 is present.
1ROCCP226
CCP2 Pin Present. When set, indicates that Capture/Compare/PWM pin 2 is present.
1ROCCP125
CCP1 Pin Present. When set, indicates that Capture/Compare/PWM pin 1 is present.
1ROCCP024
CCP0 Pin Present. When set, indicates that Capture/Compare/PWM pin 0 is present.
0ROreserved23:20
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
ADC3 Pin Present. When set, indicates that ADC pin 3 is present.1ROADC319
ADC2 Pin Present. When set, indicates that ADC pin 2 is present.1ROADC218
0ROreserved15:14
1ROC2PLUS13
Preliminary
ADC1 Pin Present. When set, indicates that ADC pin 1 is present.1ROADC117
ADC0 Pin Present. When set, indicates that ADC pin 0 is present.1ROADC016
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
C2+ Pin Present. When set, indicates that the analog comparator 2 (+) input pin is present.
June 26, 200784
LM3S2139 Microcontroller
DescriptionResetTypeNameBit/Field
1ROC2MINUS12
0ROreserved11
1ROC1PLUS10
1ROC1MINUS9
1ROC0O8
1ROC0PLUS7
1ROC0MINUS6
0ROreserved5:0
C2- Pin Present. When set, indicates that the analog comparator 2 (-) input pin is present.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
C1+ Pin Present. When set, indicates that the analog comparator 1 (+) input pin is present.
C1- Pin Present. When set, indicates that the analog comparator 1 (-) input pin is present.
C0o Pin Present. When set, indicates that the analog comparator 0 output pin is present.
C0+ Pin Present. When set, indicates that the analog comparator 0 (+) input pin is present.
C0- Pin Present. When set, indicates that the analog comparator 0 (-) input pin is present.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
85June 26, 2007
System Control

Register 17: Device Capabilities 4 (DC4), offset 0x01C

This register is predefined by the part and can be used to verify features.
Device Capabilities 4 (DC4)
Base 0x400F.E000 Offset 0x01C Type RO, reset 0x0000.00FF
DescriptionResetTypeNameBit/Field
reserved
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
GPIOAGPIOBGPIOCGPIODGPIOEGPIOFGPIOGGPIOHreserved
ROROROROROROROROROROROROROROROROType
1111111100000000Reset
0ROreserved31:8
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
GPIO Port H Present. When set, indicates that GPIO Port H is present.1ROGPIOH7
GPIO Port G Present. When set, indicates that GPIO Port G is present.1ROGPIOG6
GPIO Port F Present. When set, indicates that GPIO Port F is present.1ROGPIOF5
GPIO Port E Present. When set, indicates that GPIO Port E is present.1ROGPIOE4
GPIO Port D Present. When set, indicates that GPIO Port D is present.1ROGPIOD3
GPIO Port C Present. When set, indicates that GPIO Port C is present.1ROGPIOC2
GPIO Port B Present. When set, indicates that GPIO Port B is present.1ROGPIOB1
GPIO Port A Present. When set, indicates that GPIO Port A is present.1ROGPIOA0
Preliminary
June 26, 200786

Register 18: Run Mode Clock Gating Control Register 0 (RCGC0), offset 0x100

This register controls the clock gating logic. Each bit controls a clock enable for a given interface, function, or unit. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled (saving power). If the unit is unclocked, reads or writes to the unit will generate a bus fault. The reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. It is the responsibility of software to enable the ports necessary for the application. Note that these registers may contain more bits than there are interfaces, functions, or units to control. This is to assure reasonable code compatibility with other family and future parts. RCGC0 is the clock configuration register for running operation, SCGC0 for Sleep operation, and DCGC0 for Deep-Sleep operation. Setting the ACG bit in the Run-Mode Clock Configuration (RCC) register specifies that the system uses sleep modes.
Run Mode Clock Gating Control Register 0 (RCGC0)
Base 0x400F.E000 Offset 0x100 Type R/W, reset 0x00000040
LM3S2139 Microcontroller
16171819202122232425262728293031
SARADC0reservedCAN0reserved
R/WROROROROROROROR/WROROROROROROROType
0000000000000000Reset
0123456789101112131415
reservedWDTreservedMAXADCSPDreserved
ROROROR/WROROROROR/WR/WR/WR/WROROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:25
0R/WCAN024
0ROreserved23:17
0R/WSARADC016
0ROreserved15:12
0R/WMAXADCSPD11:8
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
CAN0 Clock Gating Control. This bit controls the clock gating for CAN unit 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
ADC0 Clock Gating Control. This bit controls the clock gating for SAR ADC module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, a read or write to the unit generates a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
ADC Sample Speed. This field sets the rate at which the ADC samples data. You cannot set the rate higher than the maximum rate. You can set the sample rate by setting the MAXADCSPD bit as follows:
DescriptionValue
250K samples/second0x1
125K samples/second0x0
Preliminary
87June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0ROreserved7:4
0R/WWDT3
0ROreserved2:0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
WDT Clock Gating Control. This bit controls the clock gating for the WDT module. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, a read or write to the unit generates a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
June 26, 200788

Register 19: Sleep Mode Clock Gating Control Register 0 (SCGC0), offset 0x110

This register controls the clock gating logic. Each bit controls a clock enable for a given interface, function, or unit. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled (saving power). If the unit is unclocked, reads or writes to the unit will generate a bus fault. The reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. It is the responsibility of software to enable the ports necessary for the application. Note that these registers may contain more bits than there are interfaces, functions, or units to control. This is to assure reasonable code compatibility with other family and future parts. RCGC0 is the clock configuration register for running operation, SCGC0 for Sleep operation, and DCGC0 for Deep-Sleep operation. Setting the ACG bit in the Run-Mode Clock Configuration (RCC) register specifies that the system uses sleep modes.
Sleep Mode Clock Gating Control Register 0 (SCGC0)
Base 0x400F.E000 Offset 0x110 Type R/W, reset 0x00000040
LM3S2139 Microcontroller
16171819202122232425262728293031
SARADC0reservedCAN0reserved
R/WROROROROROROROR/WROROROROROROROType
0000000000000000Reset
0123456789101112131415
reservedWDTreservedMAXADCSPDreserved
ROROROR/WROROROROR/WR/WR/WR/WROROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:25
0R/WCAN024
0ROreserved23:17
0R/WSARADC016
0ROreserved15:12
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
CAN0 Clock Gating Control. This bit controls the clock gating for CAN unit 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
ADC0 Clock Gating Control. This bit controls the clock gating for general SAR ADC module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, a read or write to the unit generates a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
89June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0R/WMAXADCSPD11:8
0ROreserved7:4
0R/WWDT3
0ROreserved2:0
ADC Sample Speed. This field sets the rate at which the ADC samples data. You cannot set the rate higher than the maximum rate.You can set the sample rate by setting the MAXADCSPD bit as follows:
DescriptionValue
250K samples/second0x1
125K samples/second0x0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
WDT Clock Gating Control. This bit controls the clock gating for the WDT module. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, a read or write to the unit generates a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
June 26, 200790

Register 20: Deep Sleep Mode Clock Gating Control Register 0 (DCGC0), offset 0x120

This register controls the clock gating logic. Each bit controls a clock enable for a given interface, function, or unit. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled (saving power). If the unit is unclocked, reads or writes to the unit will generate a bus fault. The reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. It is the responsibility of software to enable the ports necessary for the application. Note that these registers may contain more bits than there are interfaces, functions, or units to control. This is to assure reasonable code compatibility with other family and future parts. RCGC0 is the clock configuration register for running operation, SCGC0 for Sleep operation, and DCGC0 for Deep-Sleep operation. Setting the ACG bit in the Run-Mode Clock Configuration (RCC) register specifies that the system uses sleep modes.
Deep Sleep Mode Clock Gating Control Register 0 (DCGC0)
Base 0x400F.E000 Offset 0x120 Type R/W, reset 0x00000040
LM3S2139 Microcontroller
16171819202122232425262728293031
SARADC0reservedCAN0reserved
R/WROROROROROROROR/WROROROROROROROType
0000000000000000Reset
0123456789101112131415
reservedWDTreservedMAXADCSPDreserved
ROROROR/WROROROROR/WR/WR/WR/WROROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:25
0R/WCAN024
0ROreserved23:17
0R/WSARADC016
0ROreserved15:12
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
CAN0 Clock Gating Control. This bit controls the clock gating for CAN unit 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
ADC0 Clock Gating Control. This bit controls the clock gating for general SAR ADC module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, a read or write to the unit generates a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
91June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0R/WMAXADCSPD11:8
0ROreserved7:4
0R/WWDT3
0ROreserved2:0
ADC Sample Speed. This field sets the rate at which the ADC samples data. You cannot set the rate higher than the maximum rate. You can set the sample rate by setting the MAXADCSPD bit as follows:
DescriptionValue
250K samples/second0x1
125K samples/second0x0
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
WDT Clock Gating Control. This bit controls the clock gating for the WDT module. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, a read or write to the unit generates a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Preliminary
June 26, 200792

Register 21: Run Mode Clock Gating Control Register 1 (RCGC1), offset 0x104

This register controls the clock gating logic. Each bit controls a clock enable for a given interface, function, or unit. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled (saving power). If the unit is unclocked, reads or writes to the unit will generate a bus fault. The reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. It is the responsibility of software to enable the ports necessary for the application. Note that these registers may contain more bits than there are interfaces, functions, or units to control. This is to assure reasonable code compatibility with other family and future parts. RCGC1 is the clock configuration register for running operation, SCGC1 for Sleep operation, and DCGC1 for Deep-Sleep operation. Setting the ACG bit in the Run-Mode Clock Configuration (RCC) register specifies that the system uses sleep modes.
Run Mode Clock Gating Control Register 1 (RCGC1)
Base 0x400F.E000 Offset 0x104 Type R/W, reset 0x00000000
LM3S2139 Microcontroller
16171819202122232425262728293031
TIMER0TIMER1TIMER2reservedCOMP0COMP1COMP2reserved
R/WR/WR/WROROROROROR/WR/WR/WROROROROROType
0000000000000000Reset
0123456789101112131415
UART0UART1reservedSSI0reservedI2C0reserved
R/WR/WROROR/WROROROROROROROR/WROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:27
0R/WCOMP226
0R/WCOMP125
0R/WCOMP024
0ROreserved23:19
0R/WTIMER218
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Analog Comparator 2 Clock Gating. This bit controls the clock gating for analog comparator 2. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Analog Comparator 1 Clock Gating. This bit controls the clock gating for analog comparator 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Analog Comparator 0 Clock Gating. This bit controls the clock gating for analog comparator 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Timer 2 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 2. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
93June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0R/WTIMER117
0R/WTIMER016
0ROreserved15:13
0R/WI2C012
0ROreserved11:5
0R/WSSI04
0ROreserved3:2
Timer 1 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Timer 0 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
I2C0 Clock Gating Control. This bit controls the clock gating for I2C module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
SSI0 Clock Gating Control. This bit controls the clock gating for SSI module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WUART11
0R/WUART00
UART1 Clock Gating Control. This bit controls the clock gating for UART module 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
UART0 Clock Gating Control. This bit controls the clock gating for UART module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
June 26, 200794

Register 22: Sleep Mode Clock Gating Control Register 1 (SCGC1), offset 0x114

This register controls the clock gating logic. Each bit controls a clock enable for a given interface, function, or unit. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled (saving power). If the unit is unclocked, reads or writes to the unit will generate a bus fault. The reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. It is the responsibility of software to enable the ports necessary for the application. Note that these registers may contain more bits than there are interfaces, functions, or units to control. This is to assure reasonable code compatibility with other family and future parts. RCGC1 is the clock configuration register for running operation, SCGC1 for Sleep operation, and DCGC1 for Deep-Sleep operation. Setting the ACG bit in the Run-Mode Clock Configuration (RCC) register specifies that the system uses sleep modes.
Sleep Mode Clock Gating Control Register 1 (SCGC1)
Base 0x400F.E000 Offset 0x114 Type R/W, reset 0x00000000
LM3S2139 Microcontroller
16171819202122232425262728293031
TIMER0TIMER1TIMER2reservedCOMP0COMP1COMP2reserved
R/WR/WR/WROROROROROR/WR/WR/WROROROROROType
0000000000000000Reset
0123456789101112131415
UART0UART1reservedSSI0reservedI2C0reserved
R/WR/WROROR/WROROROROROROROR/WROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:27
0R/WCOMP226
0R/WCOMP125
0R/WCOMP024
0ROreserved23:19
0R/WTIMER218
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Analog Comparator 2 Clock Gating. This bit controls the clock gating for analog comparator 2. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Analog Comparator 1 Clock Gating. This bit controls the clock gating for analog comparator 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Analog Comparator 0 Clock Gating. This bit controls the clock gating for analog comparator 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Timer 2 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 2. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
95June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0R/WTIMER117
0R/WTIMER016
0ROreserved15:13
0R/WI2C012
0ROreserved11:5
0R/WSSI04
0ROreserved3:2
Timer 1 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Timer 0 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
I2C0 Clock Gating Control. This bit controls the clock gating for I2C module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
SSI0 Clock Gating Control. This bit controls the clock gating for SSI module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WUART11
0R/WUART00
UART1 Clock Gating Control. This bit controls the clock gating for UART module 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
UART0 Clock Gating Control. This bit controls the clock gating for UART module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
June 26, 200796

Register 23: Deep Sleep Mode Clock Gating Control Register 1 (DCGC1), offset 0x124

This register controls the clock gating logic. Each bit controls a clock enable for a given interface, function, or unit. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled (saving power). If the unit is unclocked, reads or writes to the unit will generate a bus fault. The reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. It is the responsibility of software to enable the ports necessary for the application. Note that these registers may contain more bits than there are interfaces, functions, or units to control. This is to assure reasonable code compatibility with other family and future parts. RCGC1 is the clock configuration register for running operation, SCGC1 for Sleep operation, and DCGC1 for Deep-Sleep operation. Setting the ACG bit in the Run-Mode Clock Configuration (RCC) register specifies that the system uses sleep modes.
Deep Sleep Mode Clock Gating Control Register 1 (DCGC1)
Base 0x400F.E000 Offset 0x124 Type R/W, reset 0x00000000
LM3S2139 Microcontroller
16171819202122232425262728293031
TIMER0TIMER1TIMER2reservedCOMP0COMP1COMP2reserved
R/WR/WR/WROROROROROR/WR/WR/WROROROROROType
0000000000000000Reset
0123456789101112131415
UART0UART1reservedSSI0reservedI2C0reserved
R/WR/WROROR/WROROROROROROROR/WROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:27
0R/WCOMP226
0R/WCOMP125
0R/WCOMP024
0ROreserved23:19
0R/WTIMER218
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Analog Comparator 2 Clock Gating. This bit controls the clock gating for analog comparator 2. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Analog Comparator 1 Clock Gating. This bit controls the clock gating for analog comparator 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Analog Comparator 0 Clock Gating. This bit controls the clock gating for analog comparator 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Timer 2 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 2. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
97June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0R/WTIMER117
0R/WTIMER016
0ROreserved15:13
0R/WI2C012
0ROreserved11:5
0R/WSSI04
0ROreserved3:2
Timer 1 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Timer 0 Clock Gating Control. This bit controls the clock gating for General-Purpose Timer module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
I2C0 Clock Gating Control. This bit controls the clock gating for I2C module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
SSI0 Clock Gating Control. This bit controls the clock gating for SSI module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
0R/WUART11
0R/WUART00
UART1 Clock Gating Control. This bit controls the clock gating for UART module 1. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
UART0 Clock Gating Control. This bit controls the clock gating for UART module 0. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
June 26, 200798

Register 24: Run Mode Clock Gating Control Register 2 (RCGC2), offset 0x108

This register controls the clock gating logic. Each bit controls a clock enable for a given interface, function, or unit. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled (saving power). If the unit is unclocked, reads or writes to the unit will generate a bus fault. The reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. It is the responsibility of software to enable the ports necessary for the application. Note that these registers may contain more bits than there are interfaces, functions, or units to control. This is to assure reasonable code compatibility with other family and future parts. RCGC2 is the clock configuration register for running operation, SCGC2 for Sleep operation, and DCGC2 for Deep-Sleep operation. Setting the ACG bit in the Run-Mode Clock Configuration (RCC) register specifies that the system uses sleep modes.
Run Mode Clock Gating Control Register 2 (RCGC2)
Base 0x400F.E000 Offset 0x108 Type R/W, reset 0x00000000
reserved
LM3S2139 Microcontroller
16171819202122232425262728293031
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
GPIOAGPIOBGPIOCGPIODGPIOEGPIOFGPIOGGPIOHreserved
R/WR/WR/WR/WR/WR/WR/WR/WROROROROROROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
0ROreserved31:8
0R/WGPIOH7
0R/WGPIOG6
0R/WGPIOF5
0R/WGPIOE4
0R/WGPIOD3
Software should not rely on the value of a reserved bit. To provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation.
Port H Clock Gating Control. This bit controls the clock gating for Port H. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Port G Clock Gating Control. This bit controls the clock gating for Port G. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Port F Clock Gating Control. This bit controls the clock gating for Port F. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Port E Clock Gating Control. This bit controls the clock gating for Port E. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Port D Clock Gating Control. This bit controls the clock gating for Port D. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
99June 26, 2007
System Control
DescriptionResetTypeNameBit/Field
0R/WGPIOC2
0R/WGPIOB1
0R/WGPIOA0
Port C Clock Gating Control. This bit controls the clock gating for Port C. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Port B Clock Gating Control. This bit controls the clock gating for Port B. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Port A Clock Gating Control. This bit controls the clock gating for Port A. If set, the unit receives a clock and functions. Otherwise, the unit is unclocked and disabled. If the unit is unclocked, reads or writes to the unit will generate a bus fault.
Preliminary
June 26, 2007100
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