STMicroelectronics STM32 Series Installation and operating instructions

January 2021 AN4989 Rev 3 1/118
1
AN4989
Application note
STM32 microcontroller debug toolbox
Introduction
STM32 end-users are sometimes confronted with non- or partially-functional systems during
product development. The best approach to use for the debug process is not always
obvious, particularly for inexperienced users.
To address the above concerns, this application note provides a toolbox describing the most
common debug techniques and their application to popular recommended IDEs for STM32
32-bit Arm®Cortex®MCUs. It contains detailed information for getting started as well as
hints and tips to make the best use of STM32 Software Development Tools in STM32
ecosystem.
This application note applies to the microcontrollers listed in Table 1.
Table 1. Applicable products
Type Sub class
Microcontrollers
STM32 High Performance MCUs
STM32 Mainstream MCUs
STM32 Ultra Low Power MCUs
www.st.com

Contents AN4989
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Contents
1 Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.1 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2 Software versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 STM32 ecosystem outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1 Hardware development tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.1 Hardware kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.2 ST-LINK probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.3 Alternative debugger probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 Software development tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.2.1 STM32CubeMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.2 STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.2.3 Partner IDEs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.2.4 STM32CubeProgrammer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.2.5 STM32CubeMonitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3 Embedded software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.4 Information and sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2.4.1 Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.4.2 Wiki platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4.3 Github . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4.4 ST Community . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4.5 STM32 Education . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3 Compiling for debug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.1 Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.1.1 IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.1.2 Keil®MDK-Arm µVision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.1.3 STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.2 Debugging information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.2.1 IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.2.2 Keil®-MDK-Arm µVision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.2.3 STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

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AN4989 Contents
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4 Connecting to the board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.1 SWD/JTAG pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.2 Reset and connection mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.1 Presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.2 IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.2.3 Keil®MDK-Arm µVISION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.4 STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.2.5 STM32CubeProgrammer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.3 Low-power case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
5 Breaking and stepping into code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.1 Debug support for timers, RTC, watchdog, BxCAN and I2C . . . . . . . . . . 51
5.2 Debug performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.2.1 IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
5.2.2 Keil®MDK-Arm µVISION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5.2.3 STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.3 Secure platform limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.3.1 RDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.3.2 PCROP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
6 Exception handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
6.1 Default weak Handlers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
6.2 Custom Handlers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
6.3 Trapping div/0 exception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
6.3.1 Cortex®-M0/M0+ case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
6.3.2 Cortex®-M3/4/7 case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
7 Printf debugging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
7.1 STM32 Virtual COM port driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
7.2 Printf via UART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
7.3 Printf via SWO/SWV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
7.4 Semihosting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
7.4.1 IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
7.4.2 Keil®MDK-Arm µVISION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
7.4.3 STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Contents AN4989
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8 Debug through hardware exploration . . . . . . . . . . . . . . . . . . . . . . . . . . 87
8.1 Easy pinout probing with STMicroelectronics hardware kits . . . . . . . . . . 87
8.2 Microcontroller clock output (MCO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
8.2.1 Configuration with STM32CubeMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
8.2.2 HAL_RCC_MCOConfig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
8.2.3 STM32 Series differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
9 Dual-Core microcontroller debugging . . . . . . . . . . . . . . . . . . . . . . . . . 92
10 From debug to release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
11 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Appendix A Managing DBGMCU registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
A.1 By software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
A.2 By debugger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Appendix B Use Nucleo “cuttable” ST-LINK as stand-alone VCP . . . . . . . . . . 106
Appendix C Managing various targets on the same PC . . . . . . . . . . . . . . . . . . 109
Appendix D Cortex®-M debug capabilities reminder . . . . . . . . . . . . . . . . . . . . 116
D.1 Application notes index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

AN4989 Rev 3 5/118
AN4989 List of tables
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List of tables
Table 1. Applicable products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Table 2. ST-LINK software pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 3. STMicroelectronics documentation guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 4. STM32 Series RDP protection extension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Table 5. STM32 USART vs. PC terminal WordLength example. . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Table 6. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Table 7. STM32 Series vs. debug capabilties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Table 8. STM32 Series vs. debug capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Table 9. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

List of figures AN4989
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List of figures
Figure 1. STM32 ecosystem overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 2. Development tools overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 3. Nucleo-144, Nucleo-64 and Nucleo-32 boards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 4. STM32 Nucleo-144 structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 5. Discovery board example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 6. EVAL board example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 7. 7X-NUCLEO-LPM01A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 8. ST-LINK, ST-LINK/V2, and ST-LINK/V2-ISOL stand-alone probes . . . . . . . . . . . . . . . . . . 16
Figure 9. STLINK-V3SET. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 10. On-board ST-LINK-V3 on Nucleo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 11. STM32 software development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 12. STM32CubeMX Configure and code generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 13. STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 14. STM32Cube programmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 15. STM32Cube monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 16. STM32CubeProjectList screenshot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 17. Get connected to STM32 world . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 18. IAR™ EWARM Optimization option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 19. Keil®µVision Code Optimization option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 20. STM32CubeIDE optimization level setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 21. IAR™ EWARM Generate debug Information option. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Figure 22. Keil®Debug Information option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Figure 23. STM32CubeIDE debug information option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figure 24. SWD pins PA13 and PA14 in Reset state under STM32CubeMX . . . . . . . . . . . . . . . . . . . 40
Figure 25. SWD pins PA13 and PA14 in Reserved but inactive state
under STM32CubeMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 26. SWD pins PA13 and PA14 in Active State under STM32CubeMX. . . . . . . . . . . . . . . . . . . 41
Figure 27. Reset Mode in IAR8.10: screenshot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 28. Connect and Reset option Keil®. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Figure 29. Keil®hotplug step1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Figure 30. Keil®hotplug step2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Figure 31. Keil®hotplug step3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Figure 32. Select Generator Options Reset Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Figure 33. STM32CubeProgrammer Reset mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Figure 34. STM32CubeProgrammer Connection mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Figure 35. IAR™ EWARM ST-LINK SWD Speed setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Figure 36. Keil®SWD Speed Setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Figure 37. Access to Generator Options in STM32CubeIDE V2.0.0 . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Figure 38. Asking for Handler code generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Figure 39. Keil®Access to Show Caller Code in Contextual menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Figure 40. Cortex®-M3 SCB_CCR Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Figure 41. Cortex-M3 SCB_CFSR Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Figure 42. IAR™ EWARM exception handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Figure 43. Keil®System Control and Configure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Figure 44. Keil®Fault Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Figure 45. STM32CubeIDE SCB register access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Figure 46. Fault Analyzer in STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Figure 47. Virtual COM port on Windows®PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

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Figure 48. USART Pinout configuration with STM32CubeMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Figure 49. USART2 setting with STM32CubeMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Figure 50. SWO Pin configuration with STM32CubeMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Figure 51. Semihosting/SWO configuration with IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Figure 52. IAR™ EWARM SWO Clock setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Figure 53. SWO configuration with Keil®. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Figure 54. Access to SWV in Keil®. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Figure 55. Enable SWD in STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Figure 56. Enable SWV ITM Data Console in STM32CubeIDE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Figure 57. Enable ITM stimulus Port 0 in STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Figure 58. Start Trace button in STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Figure 59. Semihosting configuration in IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Figure 60. Properties for semihosting in STM32CubeIDE- Source Location . . . . . . . . . . . . . . . . . . . . 81
Figure 61. Properties for semihosting in STM32CubeIDE- Librairies . . . . . . . . . . . . . . . . . . . . . . . . . 82
Figure 62. Properties for semihosting in STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Figure 63. Semihosting in STM32CubeIDE – Debug configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Figure 64. Semihosting in STM32CubeIDE – Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Figure 65. Semihosting in STM32CubeIDE – Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Figure 66. MCO pin selection in STM32CubeMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Figure 67. MCO alternate pin highlight exemple with L073 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Figure 68. MCO Multiplexer in STM32CubeMX Clock Configuration Pane . . . . . . . . . . . . . . . . . . . . . 89
Figure 69. STM32F4/F7 dual MCO capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Figure 70. DBMCU Register LL Library Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Figure 71. DBGMCU_CR HAL Library Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Figure 72. Access to DBGMCU register with IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Figure 73. EWARM C-SPY®Macro script setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Figure 74. Accessing DBGMCU register in Keil®MDK-Arm µVision (1/2). . . . . . . . . . . . . . . . . . . . . . 99
Figure 75. Accessing DBGMCU register in Keil®MDK-Arm µVision (2/2)) . . . . . . . . . . . . . . . . . . . . 100
Figure 76. Keil®Initialization script setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Figure 77. Access to Generator Options in STM32CubeIDE V2.0.0 . . . . . . . . . . . . . . . . . . . . . . . . . 102
Figure 78. Generator Options debug MCU in STM32CubeIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Figure 79. Access to DBGMCU settings with STM32CubeIDE V1.3.0 . . . . . . . . . . . . . . . . . . . . . . . 104
Figure 80. Runtime R/W access to DBGMCU register with SSTM32CubeIDE . . . . . . . . . . . . . . . . . 105
Figure 81. ST-LINK cuttable part of Nucleo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Figure 82. Using ST-LINK stand-alone part of Nucleo-L476RG as VCP . . . . . . . . . . . . . . . . . . . . . 107
Figure 83. Virtual COM port on PC side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Figure 84. STM32CubeProgrammer target selection pick list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Figure 85. Getting target ST-LINK S/N from the console. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Figure 86. IAR™ EWARM Debug Probe Selection pop-up window . . . . . . . . . . . . . . . . . . . . . . . . . 110
Figure 87. IAR™ EWARM Debug Probe Selection with nickname . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Figure 88. Probe selection prompt setting on IAR™ EWARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Figure 89. Keil®ST-LINK selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Figure 90. Error message for multiple ST-LINK detected in STM32CubeIDE . . . . . . . . . . . . . . . . . . 113
Figure 91. Forcing specific ST-LINK S/N with STM32CubeIDE with OpenOCD option. . . . . . . . . . . 114
Figure 92. Forcing specific ST-LINK S/N with STM32CubeIDE with ST-LINK GDB server. . . . . . . . 115

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1 Foreword
1.1 General information
This document applies to STM32 32-bit Arm®Cortex®MCUs.
Note: Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or
elsewhere.
1.2 Software versions
The various examples in this application note are illustrated on basis of the following
versions of the tools:
•IAR™ EWARM: V8.32.3
•Keil®MDK-Arm µVision: V5.26
•STM32CubeIDE: V1.3.0
•STM32CubeProg: V2.2.1
1.3 Acronyms
•AN: Application note
•CMSIS: Cortex microcontroller software interface standard
•HAL: Hardware abstraction layer (software library)
•IDE: Integrated development environment
•JTAG: Joint Test Action Group
•MCO: Microcontroller clock output
•MCU: Microcontroller unit
•NVIC: Nested vector interrupt controller
•PM: Programming manual
•RM: Reference manual
•SB: Solder bridge
•SWD: Serial wire debug
•SWO: Single wire output
•SWV: Single wire viewer
•VCP: Virtual COM port

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2 STM32 ecosystem outlines
STMicroelectronics and its partners are providing a full hardware and software ecosystem to
support rapid evaluation, prototyping, and productizing of complete systems using STM32
microcontrollers.
As presented in Figure 1, the ecosystem is composed of all the collaterals required to
develop a project with STM32.
Figure 1. STM32 ecosystem overview
This chapter provides a global overview of the main elements composing the ecosystem,
outlining debug features and useful pointers, in order to guide the user among available
resources.
2.1 Hardware development tools
This section introduces the range of available development tools from hardware kits to ST-
LINK probes and alternative debugger interfaces.
2.1.1 Hardware kits
This section lists the hardware kits provided by STMicroelectronics for STM32-based
development:
•Nucleo boards
•Discovery kits
•Evaluation boards (EVAL)
•STM32 Nucleo expansion
•Third-party boards

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Figure 2. Development tools overview
STM32 Nucleo
STM32 Nucleo boards are affordable solutions for user willing to try out new ideas and to
quickly create prototypes based on STM32 MCU.
Figure 3. Nucleo-144, Nucleo-64 and Nucleo-32 boards
STM32 Nucleo boards feature the same connectors. They can easily be extended with a
large number of specialized application hardware add-ons.
Note: Nucleo-144 boards include ST Zio connector, which is an extension of ARDUINO®Uno
rev3, and ST morpho connector.
Nucleo-68 board and Nucleo-64 boards include ARDUINO®Uno rev3 and ST morpho
connectors.
Nucleo-32 boards include ARDUINO®Nano connectors.

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All STM32 Nucleo boards integrate an ST-LINK debugger/programmer, so there is no need
for a separate probe.
The figure below shows an example of STM32 Nucleo structure
Figure 4. STM32 Nucleo-144 structure
A complete description of the embedded ST-LINK features is provided in Section 2.1.2: ST-
LINK probe on page 16. Additional information and access to Nucleo boards complete
documentation sets are available at www.st.com.

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Discovery kits
STM32 Discovery kits are a cheap and complete solution for the evaluation of the
outstanding capabilities of STM32 MCUs. They carry the necessary infrastructure for
demonstration of specific device characteristics, the HAL library, and comprehensive
software examples allow to fully benefit from the devices features and added values.
Figure 5. Discovery board example
Extension connectors give access to most of the device's I/Os and make the connection of
add-on hardware possible.
With the integrated debugger/programmer the Discovery kits are ideal for prototyping.
A complete description of the embedded ST-LINK features is provided in Section 2.1.2: ST-
LINK probe on page 16. Additional information and access to Discovery kits complete
documentation sets are available at www.st.com.

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Evaluation boards
STM32 MCU EVAL boards have been designed as a complete demonstration and
development platform for the Arm®Cortex®STM32 MCUs.
Figure 6. EVAL board example
They carry external circuitry, such as transceivers, sensors, memory interfaces, displays
and many more. The EVAL boards can be considered as a reference design for application
development.
EVAL boards have integrated ST-LINK (USB Type-B connector). For complete description
of the embedded ST-LINK features refer to Section 2.1.2: ST-LINK probe.
EVAL board has direct access to JTAG/Traces signal through dedicated Arm®JTAG 20-pin
connector allowing advanced debug (ETM). For usage of ETM traces refer to Section 2.1.3:
Alternative debugger probes on page 19.
The usage of a stand-alone probe may require some jumper and solder bridge adaptation
from default. Refer to the specific board user manual.
For further information and access to complete documentation visit
www.st.com/stm32evaltools.
STM32 nucleo expansion
STM32 Nucleo expansion boards carry all the required components to Evaluate ST devices
to be used together with an STM32 MCU.
Build STM32-based applications leveraging functionality and performance of ST’s device
portfolio.
The expansion boards are equipped with standardized interconnections, such as an
ARDUINO Uno R3 connector, or a Morpho connector for a higher level of connectivity
Each expansion board is supported by STM32-based software modules.
The combination of STM32 Nucleo boards and expansion boards is a unified scalable
approach with unlimited possibilities for application development, prototyping or product
evaluation.

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X-NUCLEO-LPM01A
This board is an example of STM32 nucleo expansion.
Figure 7. 7X-NUCLEO-LPM01A
The X-NUCLEO-LPM01A is a 1.8 V to 3.3 V programmable power supply source with
advanced power consumption measurement capability.
It performs consumption averaging (static measurement up to 200 mA) as well as real-time
analysis (dynamic measurement up to 50 mA with 100 kHz bandwidth).
The X-NUCLEO-LPM01A operates either in standalone mode (using its LCD, joystick and
button to display static measurements), or in controlled mode connected to host PC via
USB (using the STM32CubeMonPwr software tool with its comprehensive graphical user
interface).
It can be used to supply and measure the consumption of STM32 Nucleo-32, Nucleo-64,
Nucleo-68 or Nucleo-144 boards, using ARDUINO connectors.
Alternatively, it supplies and measures the consumption of any target connected by wires
via the basic connector.

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KEY FEATURES
•STM32L496VGT6 microcontroller featuring Arm®Cortex®-M4 core at 80 MHz / 100
DMIPS and three 12-bit ADC at 5 Msps
•Programmable voltage source from 1.8 V to 3.3 V
•Static current measurement from 1 nA to 200 mA
•Dynamic measurements:
– 100 kHz bandwidth, 3.2 Msps sampling rate
– Current from 100 nA to 50 mA
– Power measurement from 180 nW to 165 mW
– Energy measurement computation by power measurement time integration
– Execution of EEMBC ULPMark™ tests
•Mode standalone:
– Monochrome LCD, 2 lines of 16 characters with backlight
– 4-direction joystick with selection button
– Enter and Reset push-buttons
•Mode controlled:
– Connection to a PC through USB FS Micro-B receptacle
– Command line (Virtual COM port) or
– STM32CubeMonitor-Power PC tool.
•Four status LEDs
•Target board connectors:
– ARDUINO®Uno and Nano connectors
– Basic connector (white): 4 wires
•Flexible input power-supply options:
– USB Micro-B (VBUS)
– External power connector (7 V to 10 V)
– ARDUINO Uno and Nano connectors (pin 5 V)

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2.1.2 ST-LINK probe
The ST-LINK is the JTAG/Serial Wire Debug (SWD) interface used to communicate with any
STM32 microcontroller located on an application board.
It is available as:
•Stand-alone in-circuit debugger
•Embedded in all STM32 hardware kits (Nucleo boards, Discovery kits, EVAL boards)
ST-LINK/V2 and ST-LINK-V3 are the main used versions.
Figure 8 shows ST-LINK/V2 and ST-LINK/V2- ISOL stand-alone probes on the right.
Figure 8. ST-LINK, ST-LINK/V2, and ST-LINK/V2-ISOL stand-alone probes
Figure 9 shows the last STLINK-V3SET version.
Figure 9. STLINK-V3SET

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Figure 10 shows an example of an embedded ST-LINK/V2 as part of a Nucleo board.
Figure 10. On-board ST-LINK-V3 on Nucleo

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ST-LINK/V2 basic features
•5 V power supplied by a USB connector
•USB 2.0 full-speed-compatible interface
•USB standard Type-A to Mini- B cable
•JTAG/serial wire debug (SWD) specific features:
– 1.65 V to 3.6 V application voltage supported on the JTAG/SWD interface and 5 V
tolerant inputs
– JTAG cable for connection to a standard JTAG 20-pin pitch 2.54 mm connector
– JTAG supported
– SWD and serial wire viewer (SWV) communication supported
•Device Firmware Upgrade (DFU) feature supported
•Status LED which blinks during communication with the PC
•Operating temperature 0 °C to 50 °C
•1000 V rms high-isolation voltage (ST-LINK/V2-ISOL only)
Embedded versions usually supports the following additional features:
•Virtual COM port interface on USB. (VCP)
•Mass storage interface on USB
The availability of these additional features depends on software version.
ST-LINK-V3 basic features
•Stand-alone probe with modular extensions
•Self-powered through a USB connector (Micro-B)
•USB 2.0 high-speed compatible interface
•Direct firmware update support (DFU)
•JTAG / serial wire debugging (SWD) specific features:
– 3 V to 3.6 V application voltage support and 5 V tolerant inputs
– Flat cables STDC14 to MIPI10 / STDC14 / MIPI20 (connectors with 1.27 mm
pitch)
– JTAG communication support
– SWD and serial wire viewer (SWV) communication support
•Virtual COM port (VCP) specific features:
– 3 V to 3.6 V application voltage support on the UART interface and 5 V tolerant
inputs
– VCP frequency up to 15 MHz
– Available on STDC14 debug connector (not available on MIPI10)
•Multi-path bridge USB to SPI/UART/I2C/CAN/GPIOs specific features:
– 3 V to 3.6 V application voltage support and 5 V tolerant inputs
– Signals available on adapter board only (MB1440)
•Drag-and-drop flash programming of binary files
•Two-color LEDs: communication, power
Note: The STLINK-V3SET product does not provide power supply to the target application.

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In order to identify the ST-LINK version on a board and the related features associated with
it, please refer STMicroelectronics technical note Overview of the ST-LINK embedded in
STM32 MCU Nucleo, Discovery Kits and Eval Boards (TN1235).
On-board ST-LINK does not support JTAG port.
Note: For Nucleo and Discovery, JTAG port signal can be wired through Morpho / ARDUINO®
connectors. On EVAL boards, there is a dedicated 20-pin connector.
The use of ST-LINK requires the software packages listed in Table 2.
Note: STSW-LINK007 is included in STSW-LINK004.
STSW-LINK009 is included in most IDE installation packages (IAR Systems®, Keil®,
STM32CubeIDE) and tools.
Tip: It is recommended to use the latest firmware version of the on-board ST-LINK
interface.
Firmware upgrade can be performed thanks to the STM32CubeProgrammer (refer
to Section 2.2.4: STM32CubeProgrammer) or STM32CubeIDE.
2.1.3 Alternative debugger probes
J-LINK (Segger), I-Jet™ (IAR Systems®), and U-LINK (Keil®) are the most common
alternatives providing features equivalent to the ones provided by ST-LINK.
For most advanced debugging needs, requiring heavy traffic or ETM port tracing, ST
recommends using:
•U-Link Pro in combination with Keil®MDK-Arm µVISION
•I-Jet™ Trace in combination with IAR™ EWARM
For a complete catalog of solutions, refer to www.st.com.
Table 2. ST-LINK software pack
Part Number Description
STSW-LINK007 ST-LINK, ST-LINK/V2, ST-LINK/V2-1, STLINK-V3 boards firmware upgrade
STSW-LINK009 ST-LINK, ST-LINK/V2, ST-LINK/V2-1 USB driver signed for Windows® 7,
Windows®8, Windows®10
STLINK-V3-BRIDGE Software API compatible with the bridge interface of STLINK-V3

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2.2 Software development tools
The STM32 family of 32-bit Arm®Cortex®-M core-based microcontrollers is supported by a
complete range of software tools.
It encompasses traditional integrated development environments - IDEs with C/C++
compilers and debuggers from major third parties that are complemented with tools from ST
allowing to configure and initialize the MCU or monitor its behavior in run time.
It offers a complete flow, from configuration up to monitoring as illustrated in Figure 11.
Figure 11. STM32 software development