27.2.2 Window Mode

Just as there is a reasonable upper bound to the time the main program loop should take for each iteration, there is also in many applications a lower bound, i.e. a minimum time for which each loop iteration should run for under normal circumstances. To guard against a system failure resetting the Watchdog in a tight loop (or a failure in the system application causing the main loop to run faster than expected) a "Window" mode can be enabled to disallow resetting of the Watchdog counter before a certain period of time. If the Watchdog is not reset after the window opens but not before the Watchdog expires, the system will reset.