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4. Appendix A –Watchdog Timer
4.1 Watchdog Timer
The following parameters are references for setting the time interval of the Watchdog Timer
function. The system will regularly be “cleared” according to the set time interval. If the system
hangs or fails to function, it will also reset according to the time interval so that your system will
continue to operate.
mov dx,04e <Enter> mov al,87
<Enter> out dx,al <Enter>
out dx,al <Enter> mov dx,04e
<Enter> mov al,07 <Enter> out
dx,al <Enter>
inc dx <Enter>
inc al <Enter>
out dx,al <Enter> dec dx
<Enter> mov al,f6 <Enter>
out dx,al <Enter> inc dx
<Enter> mov al,xy <Enter>
out dx,al <Enter>
“XY” is the Watchdog Time count value for the “00h to “FFh” range wherein the time can be
set from 0 sec. to 255 sec.
