Using ALE to fire the watchdog means the same as no watchdog was used at all !

Since the ALE signal was permanently active, also if the µC hangs in an endless loop.

Then it is cheaper to use an only reset circuit.


But if the watchdog should only be disabled temporary e.g. during development, I use the MAX813L.

It has a tree state input, which cause, that the watchdog was disabled if the input was disconnected from the µC e.g. with a jumper.


Peter