Aaeon SBC-656, Manual

Page: 92 / 103

Appendix A Watchdog Timer 83
What the decoded address of the W83977 ?
The decoded address of the W83977 is 3F0h.
How to enter or exit the configuration mode ?
In order to enter the configuration mode, you must write the
value
87h
to the configuration port
3F1h 2 times
each.
In order to exit the configuration mode, you must write the
value
AAh
to the configuration port
3F1h.
How to enable or disable the Watchdog Timer
?
In order to enable the Watchdog Timer, you must write the
value
01h
to the register 30 (
CR30
) of the Logic Device
7.
In order to disable the Watchdog Timer, you must write the
value
00h
to the register 30 (
CR30
) of the Logic Device
7
How to set time-out value ?
In order to set time-out value, you must write a value which
is between 01h and FFh
to the register F2 (
CRF2
) of the Logic Device 8.
For example,
01h : Time-out occurs after 32 seconds (16 seconds for the