Advantech PCE-5130, User Manual

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PCE-5130 User Manual 68
A.1 Introduction
The PCE-5130’s watchdog timer can be used to monitor system software operation
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 W83627HF super I/O controller. It provides the
following user programmable functions:
! 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 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).
Unlock W83627HF
Select register of
watchdog timer
Enable the function of
the watchdog timer
Use the function of
Lock W83627HF
the watchdog timer