Boser HS-6200 Manual page 19

The Watch-dog timer is disabled after the system Power-On. The
watch-dog timer can be enabled by a Enable cycle with reading the
control port (443H), a Refresh cycle with reading the control port
(443H) and a Disable cycle by reading the Watch-dog timer disable
control port (043H). After a Enable cycle of WDT, user must
constantly proceed a Refresh cycle to WDT before its period setting
comes ending of every 1, 2, 10, 20, 110 or 120 seconds which pre-
setting by JP4. If the Refresh cycle does not active before WDT
period cycle, the on board WDT architecture will issue a Reset or
NMI cycle to the system.
The Watch-Dog Timer is controlled by two I/O ports.
443H
443H
043H
The following sample programs showing how to Enable, Disable and
Refresh the Watch-dog timer:
WDT_EN_RF
WDT_DIS
WT_Enable
WT_Rresh
WT_DISABLE
I/O Read The Enable cycle.
I/O Read The Refresh cycle.
I/O Read The Disable cycle.
EQU 0443H
EQU 0043H
PUSH AX
PUSH DX
MOV DX,WDT_EN_RF
IN AL,DX
POP DX
POP AX
RET
PUSH AX
PUSH DX
MOV DX,WDT_ET_RF
IN AL,DX
POP DX
POP AX
RET
PUSH AX
PUSH DX
MOV DX,WDT_DIS
IN AL,DX
POP DX
POP AX
RET
; keep AX DX
; enable the watch-dog timer
; get back AX, DX
; keep AX, DX
; refresh the watch-dog timer
; get back AX, DX
; disable the watch-dog timer
; get back AX, DX
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