I had a circuit with
ATmega644PA and use internal watchdog timer to bring the controller from a hang state to known by a reset. but my code still hangs in some loop somewhere, and causes the system to be non-responsive.
So I need to use an external reset source that can work to monitor a pin of microcontroller, if the pin status remains constant for more than, suppose, 60 secs it will reset the controller.
In my application code I will provide pulse on the pin regularly.
Other suggestions welcome.