Advantech ASR-3100PP-R11A1E, User Manual

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ASR-3100 Series User Manual 74
The ASR-3100’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 hardware monitor NCT7902. It provides the fol-
lowing functions for user programming:
 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.2 Programming the Watchdog Timer
The Watch Dog timer programming steps as below:
1. Set Bank0 CR[E1h] Bit0 to 1 to enable Soft Watch Dog.
2. Set Bank0 CR[E3h] Timeout timer for Soft Watch Dog.
3. Set Bank0 CR[E0h] to 55h to enable Soft Watch Dog Timer. Set to AAh will dis-
able Soft Watch Dog Timer.
4. The Soft Watch Dog will start count down.
5. When the timer that we set to CR[E3h] is timeout , WDTRST# will issue low
pulse signal.
6. The Bank0 CR[E2h] is Watch Dog Status Register for reading.