Advantech PCE-5120 Programming the Watchdog Timer, Watchdog timer overview, Jumper selection

Appendix A Watchdog Timer

A.1 Programming the Watchdog Timer

The PCE-5120'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 program it.

A.1.1 Watchdog timer overview

The watchdog timer is built in to the super I/O controller W83627HF. 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 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 Jumper selection

The JWDT1 jumper is used to select reset in the event the watchdog timer is tripped. See Chapter 1 for detailed jumper settings.

A.1.3 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).

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