AAEON PFM-535S - Manual (Page 40)

P C / 1 0 4 C P U M o d u l e P F M - 5 3 5 S
Appendix A Programming the Watchdog Timer A-7
WDT1 DOS Example
#include <stdio.h>
#include <conio.h>
void main()
{
unsigned char c;
unsigned long lTime;
// 500 mini-second
lTime = 0x20L * 500L;
outp(0x6c, (lTime >> 16) & 0xff);
outp(0x6b, (lTime >> 8) & 0xff);
outp(0x6a, (lTime >> 0) & 0xff);
// Reset system. For example, 0x50 to trigger IRQ7
outp(0x69, 0xd0);
// Enable watchdog timer
c = inp(0x68);
c |= 0x40;
outp(0x68, c);
printf("Press any key to stop trigger timer.\n");
while(!kbhit())
outp(0x67, 0x00);
printf("System will reboot after 500 milli-seconds.\n");
}