EMAC PCA-6782, User Manual

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61 PCA-6782 User Manual
Appendix A
P
rogramming
the
W
atchdog
Timer
A.1.4 Example Program
1. Enable watchdog timer and set 10 sec. as timeout interval
;--------------------------------------------------------------------------------
Mov dx,2e
; Unlock W83627DHG-P
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 W83627DHG-P
Mov al,0aah
Out dx,al
2. Enable watchdog timer and set 5 minutes as timeout interval
;--------------------------------------------------------------------------------
Mov dx,2eh
; unlock W83627DHG-P
Mov al,87h
Out dx,al
Out dx,al