A Watchdog Timer - Aaeon PCM-4335 Manual

Following is an Example of programming 16 seconds period for
watchdog timer in assembly language. When timer times out, it
will generate system reset.
.model small
.code
CONFIG_PORT
DATA_PORT
SetWatchDog_Time PROC
push bx
push cx
push dx
mov bl,7
mov ax,0130h
call W977Write
mov bl,8
mov ax,01f2h
call W977Write
pop dx
pop cx
pop bx
mov ah,4ch
int 21h
ret
dw 3f0h
dw 3f1H
;; Select Logical Device Number 7
;; Register 30h write 01h to Active Function
;;
;; Select logical Device Number 8
;; Register F2h write Time-out value (01h)
;; watchdog time-out value is 16 sec
Appendix A Watchdog Timer 75