SMC Networks SpacePC 1232 Series - Manual (Page 69)

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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