Watchdog Timer Overview; Programming The Watchdog Timer - Advantech SKY-6200 User Manual

The SKY-6200'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

Watchdog Timer Overview

The watchdog timer is built in to the EC controller IT8528E. It provides the following
functions for user programming:
 Can be enabled and disabled by user's program
 Timer can be set from 1 to 255 seconds
 Generates an interrupt or reset signal if the software fails to reset the timer
before time-out
A.2

Programming the Watchdog Timer

The I/O port address of the watchdog timer is as below:
Address
0x57
0x5E
0x5F
Here is an example to step by step program the Watchdog Timer.
Step Action
00 Read 0x299 port
Wait IBF clear
01 Write 0x89 to 0x29A
Wait IBF clear
02 Write 0x5E to 0x299 port
Wait IBF clear
03 Write 0x00 to 0x299 port
Wait IBF clear
04 Write 0x89 to 0x29A
Wait IBF clear
05 Write 0x5F to 0x299 port
Wait IBF clear
06 Write 0x64 to 0x299 port
Wait IBF clear
07 Write 0x89 to 0x29A
Wait IBF clear
SKY-6200 User Manual
Description
Event - Warm Reset: 0x04
Warm Reset Timer (High BYTE)
Warm Reset Timer (Low BYTE)
Description
Clear I/O port
0x29A, BIT1, = 0
0x29A, BIT1, = 0
0x29A, BIT1, = 0
Set 10 sec (high byte)
0x29A, BIT1, = 0
0x29A, BIT1, = 0
0x29A, BIT1, = 0
Set 10 sec (low byte)
0x29A, BIT1, = 0
0x29A, BIT1, = 0
82
Based 100ms