Programming The Watchdog Timer; Watchdog Timer - Aaeon MB-662 User Manual

Programming
How to program the WATCHDOG TIMER
1. To set the time-out interval of watchdog timer:
-- output the desired value to port 0x443. Since the data is of 1
byte, the maximum value will be 255. In our design 2 ~ 255 will
denote 2 ~ 255 sec.
outportb(0x443, 30 <HEX>); // set watchdog to 30 seconds
2. To set the time-out event:
-- output data to port 0x444,
Timeout =SEC.Q=1
WDRST=IRQSET=3 & TIMEOUT
IRQ15=IRQSET=2 & TIMEOUT
IRQ11=IRQSET=4 & TIMEOUT
IRQ10=IRQSET=5 & TIMEOUT
outportb(0x444, 3); // set time-out event to reset-system
3. To disable watchdog timer:
-- output value 0 to port 0x443
outportb(0x443, 0); // disable watchdog timer
4. To ebable or refresh watchdog timer(the watchdog timer will
return to its initial value, then count down):
-- access the I/O port 0x443, e.g.
106 MB-662 User Manual
the watchdog timer