69
69
Watchdog time-out pin
For external control purposes, the status of the watchdog time-out event is provided to connector
J11 pin 9. This signal goes high when the watchdog resets the system. The software can reset
this signal by setting and resetting bit 2 of the I/O port 110h. This signal is also initialized by
hardware at power-on.
The following example shows how to reset the watchdog time-out pin:
MOV
DX, 110h
; Control Port
IN
AL, DX
; Read actual value
OR
AL, 04h
; Mask reserved bits and set bit 2
OUT
DX, AL
; Write new value
AND
AL,
FBh ;
Mask reserved bits and reset bit 2
OUT
DX, AL
; Write new value
