Watchdog Usage Guide

Using the Watchdog

The SiFli SF32LB55X chip provides a corresponding watchdog for both HCPU and LCPU. In the SDK, you can enable the watchdog by enabling the following switch in the project via menuconfig.

This switch enables the chip’s hardware watchdog and also activates the RT-Thread watchdog software driver. The default watchdog timeout is 30 seconds.

If you need to modify the watchdog’s timeout, you can make the following configuration in menuconfig:

Notes

  • The system will automatically feed the watchdog in the IDLE thread. If other threads do not run continuously beyond the watchdog’s timeout, no additional code is needed.

  • If the user has a high-priority thread that needs to run continuously beyond the watchdog timeout (this use case is rare), the user needs to call rt_hw_watchdog_pet() in the corresponding thread to ensure the watchdog is fed before the timeout occurs.

  • When the system enters Standby/hibernate sleep modes, the watchdog will be disabled. It will be re-enabled when the system wakes up. In other sleep modes, the watchdog will continue running. The system must be woken up and fed the watchdog before the timeout.

  • The HCPU uses the system watchdog. When triggered, it will reset the entire chip.

  • The LCPU uses the LCPU subsystem’s watchdog. When triggered, it generates an interrupt. The interrupt handler will trigger a software restart of the entire chip.