Advantech AIMB-225, User Manual

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AIMB-225 User Manual 72
A.1 Programming the Watchdog Timer
The AIMB-225'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 into the super I/O controller NCT6106D. It provides the
following user-programmable functions:
 Can be enabled and disabled by user 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
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 assign the address of register
by writing an address value into address port 2E (hex), then write/read data to/from
the assigned register through data port 2F (hex).