User`s manual

121
C
Watchdog Timer
Appendix C - Watchdog Timer
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.
;============= PROGRAM START ==============
Secondio_Config_Port EQU 2EH
Entry_Key EQU 87H
Watch_Dog_Timer EQU 14H ;20Second
;***************************************
code segment
assume cs:code,ds:code
org 100h
;———————————————————
start:
mov dx, Secondio_Config_Portÿ
mov al, Entry_Key
out dx, al
out dx, al
mov dx, Secondio_Config_Port
mov al, 07H
out dx, al
mov al, 08H
inc dx
out dx, al
mov dx, Secondio_Config_Port
mov al, 30H
out dx, al
mov al, 01H
inc dx
out dx, al
mov dx, Secondio_Config_Port
mov al, 60H
out dx, al
mov al, 03H