Habey PRO-6820 - Manual (Page 65)

Appendix 2: Watchdog Programming Guide
Watchdog reference code
Set the port to realize watchdog function through DEBUG order,
so that it can carry out Watchdog Timer’s various functions.
void main()
{
int indexp = 0x2e,datap = 0x2f;
unsigned char temp;
outportb(indexp,0x87);
outportb(indexp,0x01); //unlock
outportb(indexp,0x55);
outportb(indexp,0x55);
outportb(indexp,0x07);
outportb(datap,0x07);
outportb(indexp,0x71);
outportb(datap,0x80); //enable logical device
outportb(indexp,0x72);
outportb(datap,0xc0); //set second
/*outportb(datap,0x40); set minute*/
outportb(indexp,0x73);
outportb(datap,0x03); //set 3 seconds
outportb(indexp,0x74);
outportb(datap,0x00);
outportb(indexp,0x02);
temp = (unsigned char)inportb(datap);
temp |= 0x02;
outportb(datap,temp); //lock
}
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