Introduction; Watchdog Timer Overview; Programming The Watchdog Timer - Advantech PCE-3029 User Manual

A.1

Introduction

The PCE-3029/4129's watchdog timer can be used to monitor system software oper-
ation and take corrective action if the software fails to function within the programmed
period. This section describes the operation of the watchdog timer and how to pro-
gram it.
A.1.1

Watchdog timer overview

The watchdog timer is built in to the NCT6776D super I/O controller. It provides the
following user programmable functions:

Can be enabled and disabled via user's program

Timer can be set from 1 to 255 seconds or 1 to 255 minutes

Generates a reset signal if the software fails to reset the timer before time-out
A.1.2

Programming the watchdog timer

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 write an address value into
address port 2E (hex), then write/read data to/from the assigned register through
data port 2F (hex).
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