Showing results for 
Search instead for 
Did you mean: 

STM32H7 debug dual core

Associate III

Hi everybody,

just some info regarding debug with dual core. 

1. In Stm32CubeIde is it possible to debug a NUCLEO board equipped with STM32H755 with the two sessions contemporary alive? (The debugger mounted on NUCLEO board is STLINK-V3)
2. Is it possible to perform a single step debug (that should mean a step on both cores)?

I read the documents:

- AN5361

- AN5286

and video:

I noticed a discrepancy between the video and the AN5361. At page 12 the AN reports "Since the STM32CubeMX default project puts the Cortex-M4 in the Deepsleep mode, the [Reset behaviour] field must be set to Connect under reset to be able to communicate with the CPU (refer to Figure 12). The Halt all cores option must not be set." In the video at min 11:30 seems enabled. Who is right?

Question answered by @Sarra.S !

The target 1 to is possible only by "Launch Group". If someone has another solution, please tell me how.


About the point 2. Currently I've no results... Therefore, if someone knows... 

Thank you



ST Employee

Hello @lonejack

In AN5361, the selected project (imported from STM32H7Cube package) puts CM4 in sleep mode by default, so that CM7 can wake it up, that's why the note "The Halt all cores option must not be set." is there, otherwise the CM4 won't enter sleep mode, so this is a specific case

The halt all cores option must be set when both cores are working together for a shared task and you want to keep their states synchronized for debugging purposes. So, if a breakpoint is hit or if you manually pause execution in one core, the other core will also be halted. 

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

@Sarra.S, thank you for your answer. My mistake. Now, when you debug with dual core, do you expect to be allowed to proceed by step on both processors?

To me this don't happen...

Furthermore, in the video seems that is only necessary to debug configuration dedicated to CM7 (the CM4 is loaded automatically)... If I do the same thing, I see only CM7 side. If I want to see both I need to run the Launch Group configuration. But also in this case the step by step for both processor doesn't works..


Have you any idea?

Thank you