User manual

IPPC-6152A Series User Manual 72
Appendix C Watchdog Timer
C.1 Overview
The IPPC-9070 cards’ watchdog timer can be used to monitor system
software operation and take corrective action if the software fails to func-
tion after the programmed period. This section describes the operation of
the watchdog timer, and how to program it. The watchdog timer is built
into the super I/O controller W83627HF. It provides the following func-
tions for user programming:
• Can be enabled and disabled by user's program.
• Timer can be set from 1 to 255 seconds or 1 to 255 minutes.
• Generates an interrupt or resets signal if the software fails to reset the
• timer after time-out.
C.2 Watchdog Timer Programming
The I/O port address of the watchdog timer is 2E(hex) and 2F(hex), 2E
(hex) is the address port. 2F(hex) is the data port. You must first assign
the address of register by writing address value into address port 2E(hex),
then write/read data to/from the assigned register through data port 2F
(hex).