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Watchdog

LibXR supports automatic management of the STM32 independent watchdog (IWDG), including either timer-task feeding or a dedicated thread. Enabling a hardware watchdog is generally recommended for production firmware.

Basic Notes​

  • supports automatic code generation and configuration for enabled IWDG instances
  • optional auto-feed mode: timer task or dedicated thread, suitable for bare-metal or RTOS-based projects
  • watchdog period, thread stack, and thread priority can be configured through YAML

Example Generated Code​

// Create and initialize the watchdog instance
STM32Watchdog iwdg1(&hiwdg1, 1000, 250); // 1 s timeout, 250 ms feed interval

// Auto-feed option 1: timer task, suitable for bare-metal or simple polling
auto iwdg1_task = Timer::CreateTask(iwdg1.TaskFun, reinterpret_cast<LibXR::Watchdog *>(&iwdg1), 250);
Timer::Add(iwdg1_task);
Timer::Start(iwdg1_task);

// Auto-feed option 2: dedicated thread, suitable for RTOS
LibXR::Thread iwdg1_thread;
iwdg1_thread.Create(reinterpret_cast<LibXR::Watchdog *>(&iwdg1), iwdg1.ThreadFun, "iwdg1_wdg", 1024,
                   static_cast<LibXR::Thread::Priority>(3));

Configuration File​

The watchdog behavior is controlled through configuration such as:

# IWDG peripheral enablement and instance parameters
IWDG:
  iwdg1:
    timeout_ms: 1000
    feed_interval_ms: 250

# Global watchdog behavior
Watchdog:
  run_as_thread: true
  thread_stack_depth: 1024
  thread_priority: 3
  feed_interval_ms: 250

If run_as_thread: true, each enabled IWDG gets a generated thread and uses the global thread parameters.

If run_as_thread: false, the generator emits the timer-task feeding pattern instead.

Current generator coverage​

In current GeneratorCodeSTM32.py, the watchdog generation path mainly does the following:

  • generate one STM32Watchdog instance for each enabled IWDG;
  • read constructor parameters from IWDG.<instance>.timeout_ms and feed_interval_ms;
  • choose thread-based or timer-task-based feeding according to the global Watchdog.run_as_thread flag.

Specifically:

  • thread mode uses global thread_stack_depth and thread_priority;
  • non-thread mode uses the global feed_interval_ms as the period passed to Timer::CreateTask(...).

Regeneration Command​

After editing libxr_config.yaml, regenerate with:

xr_gen_code_stm32 -i ./.config.yaml -o ./User/app_main.cpp

Notes​

STM32CubeMX-generated MX_IWDG_Init() usually enables the watchdog immediately, and the hardware cannot then be disabled or reconfigured except by reset. If needed, disable generation/invocation of that function in CubeMX under Project Manager -> Advanced Settings.