Boser HS-6010, Manual, Page: 19 / 37

17
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 JP6. 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 I/O Read The Enable cycle.
443H I/O Read The Refresh cycle.
043H I/O Read The Disable cycle.
The following sample programs showing how to Enable, Disable and
Refresh the Watch-dog timer:
WDT_EN_RF EQU 0443H
WDT_DIS EQU 0043H
WT_Enable PUSH AX ; keep AX DX
PUSH DX
MOV DX,WDT_EN_RF ; enable the watch-dog timer
IN AL,DX
POP DX ; get back AX, DX
POP AX
RET
WT_Rresh PUSH AX ; keep AX, DX
PUSH DX
MOV DX,WDT_ET_RF ; refresh the watch-dog timer
IN AL,DX
POP DX ; get back AX, DX
POP AX
RET
WT_DISABLE PUSH AX
PUSH DX
MOV DX,WDT_DIS ; disable the watch-dog timer
IN AL,DX
POP DX ; get back AX, DX
POP AX
RET