VSCode GDB Debug - Enable Watchdog Halt

[shayesMEL]

Hi,

I am not sure how to categorize this problem. I have a custom board that I had done an initial software development cycle on STM32CubeIDE. I am working a newer version in VSCode with the STM32 Extension. Everything is working with the exception of one problem. I am using a watchdog on my MCU (STM32L4R9ZGJ6), which triggers while I have the processor halted. I know how to fix this in CubeIDE (Debugger tab, Enable Suspend Watchdogs) but cannot figure it out on the VSCode/GDB side. Below is the launch.json I have so far:

{
  "version": "0.2.0",
  "configurations": [
    {
      "cwd": "${workspaceFolder}",
      "executable": "./build/debug/build/test.elf",
      "name": "Debug with ST-Link",
      "request": "launch",
      "type": "cortex-debug",
      "runToEntryPoint": "main",
      "showDevDebugOutput": "none",
      "servertype": "stlink"
      
    },
    
    {

      "name": "Launch",
      "type": "cppdbg",
      "request": "launch",
      "cwd": "${workspaceFolder}",
      "program": "${command:cmake.launchTargetPath}",
      "MIMode": "gdb",
      "miDebuggerPath": "${command:vscode-embedded.st.gdb}",
      "miDebuggerServerAddress": "localhost:3333",
      "debugServerPath": "${command:vscode-embedded.st.gdbserver}",
      "debugServerArgs": "--stm32cubeprogrammer-path ${command:vscode-embedded.st.cubeprogrammer} --swd --port-number 3333",
      "serverStarted": "Waiting for connection on port .*\\.\\.\\.",
      "stopAtConnect": true,
      "postRemoteConnectCommands": [
        {
          "text": "load build/debug/build/UPADermitron.elf"
        }
      ],
      "logging": {
        "engineLogging": true
      },
      "preLaunchTask": "Build",
      "svdPath": "${command:vscode-embedded.st.svd}/STM32L4R9.svd"
    }
  ]
}

Any help is appreciated! Sorry if this has come up but I have tried to find with no luck.

[Mikk Leini]

Hello ST! Waiting for an answer.

[LaurentL]

Hello,

To freeze WDGs counters when halted, you need to update the DBGMCU registers.

In "STM32CUBE REGISTERS TREE" view, open DBGMCU registers and in APB1_FZR1 register, you need to set the DBG_WWDG_STOP and/or DBG_IWDG_STOP register bits.

Regards,

Laurent

[Mikk Leini]

Hi @LaurentL.

Is there any vscode debug option to do it automatically? Feature request!?!

If doing it programmatically, clock needs to be enabled also:

__HAL_RCC_DBGMCU_CLK_ENABLE();
__HAL_DBGMCU_FREEZE_IWDG(); /* and/or */ __HAL_DBGMCU_FREEZE_WWDG();

[LaurentL]

Hi,

This feature is under development on STM32CubeIDE for Visual Studio Code and should be available for next version.

"Low Power Modes" and "Watchdogs Freeze" will have a server attribute in launch configuration.

"RCC DBGMCU CLK Enable" is not present on STM32L4 devices so I didn't mentioned it.

But it is on some other series like STM32L0/G0/C0...

[Mikk Leini]

Great to hear it's coming.

Thanks for clarifying the debug clock difference.

However I use STM32N6 and for some reason, if I call the lines that I wrote above, then device does not run without debugger - it just hangs. Doesn't even make a watchdog reset. Didn't check in details what happens. The cure is to allow freezing IWDG only when debugger is connected:

if ((CoreDebug->DHCSR & CoreDebug_DHCSR_C_DEBUGEN_Msk) != 0U)
{
  __HAL_RCC_DBGMCU_CLK_ENABLE();
  __HAL_DBGMCU_FREEZE_IWDG();
}