Aaeon PCM-4896 User Manual page 119

outportb(0x444, 0):
outportb(0x443x 10);
customer_job();
outportb(0x443, 0);
outputb(0x443, 20);
another_job();
outportb(0x443, 0)
...
...
// set time-out event to reset-system
// set time-out interval to 10 seconds
// execute your job here, be sure your
job will finished within 10 seconds
// refresh watchdog timer, otherwise
the system will reset after time-out
// set time-out interval to 20 seconds
// another job finished in 20 seconds
// disable watchdog timer
Appendix A Programming the Watchdog Timer 107