User`s manual

Watchdog Timer Control

The cpuModule includes a Watchdog Timer, which provides protection against programs "hanging",

or getting stuck in an execution loop where they cannot respond correctly. When enabled, the

Watchdog Timer must be periodically reset by your application program. If it is not reset before the

timeout period of 1.2 seconds expires, it will cause a reset of the cpuModule.

Three functions have been implemented on the cpuModule for Watchdog Timer control. These are:

• Watchdog Timer enable

• Watchdog Timer disable

• Watchdog Timer reset

You may control the watchdog timer using functions of software interrupt 52H listed below.

Function 0CH Watchdog Timer enable

INPUTS: AH = 0CH

RETURNS: None

Function 0DH Watchdog Timer disable

INPUTS: AH = 0DH

RETURNS: None

Function 0EH Watchdog Timer reset

INPUTS: AH = 0EH

RETURNS: None