IBM SBC-658 manual Each

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

Appendix A Watchdog Timer 97