Just reset the watchdog counter as part of the main system loop. Here is some pseudo code...

<>< Lance.


boolean dont_stop = true;

initialize_everything();

while (dont_stop) // Main loop
{
  scan_input();
  do_some_calculations();
  display_something();
  reset_watchdog();
}// end of main loop


void reset_watchdog() {
  out(WATCHDOG_PORT, WATCHDOG_RESET_BIT);
}// reset_watchdog()