ADLINK Technology NuPRO-842 Series, User Manual

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Watchdog Timer 41
NuPRO-842
5 Watchdog Timer
This chapter explains the operation of the NuPRO-842 watchdog
timer. It provides an overview of watchdog operations and features.
Sample programs are located at X:\CHIPDRV\WDT\DOS\NP842.
5.1 Watchdog Timer Overview
The primary function of the watchdog timer is to monitor the
NuPRO-842 operation and to reset the system if the software fails
to function as programmed. The major features of the watchdog
timer are:
X
Enabled and disabled through software control
X
Armed and strobed through software control
Figure 5-1: Watchdog Timer Architecture
The NuPRO-842 custom watchdog timer circuit is implemented in a
programmable logic device. The watchdog timer contains two
"Control and Status Registers."
X
The watchdog times out after a selected timeout interval.
X
A hard reset occurs.
The timeout period is 1 – 255 seconds or 1 – 255 minutes.
Using the Watchdog in an Application
The following topic is provided to help users learn how to use the
watchdog in an application. The watchdog reset function is also
described. The watchdog reset is controlled through the watchdog
"Control and Status Registers".