In one of our projects, we are observing MCU hanging up supposedly due to EFT. WDT is not helping. The only way to get the device into working condition is to reset the MCU by reset pin or power cycle.
Resetting/power cycle is not the most convenient way of solving this issue. I have an idea which can solve the issue but I am not sure how to implement it or whether a standard IC exists that can do the job. This IC should not be an MCU because this IC itself can hang.
Idea is to generate a low frequency PWM by toggling a GPIO which is then fed to a circuit/IC. The circuit/IC resets the MCU if it doesn't receive a PWM. I specifically need a PWM instead of constant HIGH/LOW because when the system hangs, the PIN can either get stuck to a HIGH or a LOW position.