Advantech PCA-6743, User Manual

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51 PCA-6743 User Manual
Appendix B
P
rogramming
the
W
atchdog
Timer
B.1.3 Example Program
1. Enable watchdog timer and set 10 sec. as timeout interval
;-----------------------------------------------------------
Mov
dx, 2Eh; Unlock W83627-DHG-P
Mov al, 87h
Out dx, al
Out dx, al
;-----------------------------------------------------------
Mov
dx, 2Eh; Pin 77 Select as WDTO#
Mov al, 2Dh
Out dx, al
Inc dx
In al, dx
And al, not 00000001b
Out dx, al
;-----------------------------------------------------------
Mov
dx, 2Eh; Select Logical Device 8 of watchdog timer
Mov al, 07h
Out dx, al
Inc dx
Mov al, 08h
Out dx, al
;-----------------------------------------------------------
Mov
dx, 2Eh; Enable the function of watchdog timer
Mov al, 30h
Out dx, al
Inc dx
Mov al, 01h
Out dx, al
;-----------------------------------------------------------
Mov
dx, 2Eh ; Set second as counting unit
Mov al, F5h
Out dx, al
Inc dx
In al, dx
And al, not 08h
Out dx, al
;-----------------------------------------------------------
Mov
dx, 2Eh ; Set timeout interval as 10 seconds and start counting
Mov al, F6h
Out dx, al
Inc dx
Mov al,10
Out dx, al
;-----------------------------------------------------------
Mov
dx, 2Eh; Lock W83627-DHG-P
Mov al, AAh