STM32H755 Dual Debug Startup Problem

[bramble]

Hi community,

I have a problem that other people have also raised and I'd be grateful for help.

I followed AN5361 and I watched this STM video on the same topic. First thing to mention is that the video and doc have different advice about whether the CM7 should Halt All Cores (Video advice) or not (AN5361 advice). Grrr!

Now I've got that off my chest here's the problem in more detail.

CM7 like this:

CM4:

With that configuration when I launch CM7 first, then CM4, both pause as expected with CM4 in reset and CM7 ready to go. When I select both cores then click on the green go arrow, CM7 runs straight into this:

Caused by the timeout expiring.

If, alternatively, I configure CM7 like this:

Then I can debug both cores, but they aren't doing a coordinated start as they should.

I know that I could ignore the timeout error, but then the systems wouldn't be doing a coordinated start as they should.

Any suggestions please?

[KDJEM.1 · Accepted solution]

Hello @bramble,

Which STM32CubeIDE version are you using?

Do you encounter any issues when following Getting started with projects based on dual-core STM32H7 microcontrollers in STM32CubeIDE application note (with the Halt all cores option unchecked)?

May be this discussion can help you.

Thank you.

Kaouthar

[bramble]

Hi @KDJEM.1 , thank you for your help.

When I reported this issue I was using Vn 1.17 but today I've switched to 1.18 and the issue still exists.

I have followed the instructions in the discussion that you mentioned, which are I think the same as the relevant AN.

However, I have found that if I set the CM4 in the mode shown below then I can proceed without having to disable the CM7 timeout check:

I'm OK with this, since I have a solution that works.

Thanks again for your help.

[Christophe VRIGNAUD]

Hello,

If you check the halt all cores, the best is to avoid launching both cores.

1. Start the M7 debug => the M7 and the M4 are both halted at the beginning of their main.
At this stage, in the debugger you just have the M7 target:

2. Start the M4 debug => Hot attach to the M4 which is halted at the beginning of its main function.

3. Start the M4 => it goes in stop mode

Here you get a dummy screen => don't give attention to the address given, just keep in mind that the M4 core in in stop mode. 

4. Now you can start the M7. It will execute the HAL init and the config clock and continue running or stop on the next breakpoint.

5. Resume the M4.

At this stage, both cores are running.

[bramble]

Hi @Christophe VRIGNAUD many thanks for your detailed advice, much appreciated.