Advantech AIMB-258 - Manual (Page 67)

59 AIMB-258 User Manual
Appendix A
P
rogramming
the
W
atchdog
Timer
A.1.3 Example Program
1. Enable watchdog timer and set 10 sec. as timeout interval
;-----------------------------------------------------------
Mov dx,2eh ; Unlock W83627UHG
Mov al,87h
Out dx,al
Out dx,al
;-----------------------------------------------------------
Mov al,07h ; Select registers of watchdog timer
Out dx,al
Inc dx
Mov al,08h
Out dx,al
;-----------------------------------------------------------
Dec dx ; Enable the function of watchdog timer
Mov al,30h
Out dx,al
Inc dx
Mov al,01h
Out dx,al
;-----------------------------------------------------------
Dec dx ; Set second as counting unit
Mov al,0f5h
Out dx,al
Inc dx
In al,dx
And al,not 08h
Out dx,al
;-----------------------------------------------------------
Dec dx ; Set timeout interval as 10 seconds and start counting
Mov al,0f6h
Out dx,al
Inc dx
Mov al,10
Out dx,al
;-----------------------------------------------------------
Dec dx ; lock W83627UHG
Mov al,0aah
Out dx,al
2. Enable watchdog timer and set 5 minutes as timeout interval
;-----------------------------------------------------------
Mov dx,2eh ; unlock W83627UHG
Mov al,87h
Out dx,al
Out dx,al