RM0319 datasheet(347/368 Pages) STMICROELECTRONICS

347 / 368 page

RM0319

Watchdog timer (WDT)

Doc ID 022640 Rev 3

347/368

Watchdog timer (WDT)

This chapter describes the functionality and operation of the watchdog timer.

For technical details about the programmable registers related to the watchdog timer, refer

to the watchdog timer registers in the following companion document:

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RM0321: SPEAr320S address map and registers

34.1

Overview

Within its basic subsystem, the device provides an ARM watchdog module. It consists of a

32-bit down counter with a programmable time-out interval that has the capability to

generate an interrupt and a reset signal on timing out. The watchdog module is intended to

be used to apply a reset to a system in the event of a software failure.

34.2

Main features

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32-bit down counter with a programmable time-out interval

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Separate watchdog clock with its clock enable for flexible control of the time-out interval

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Interrupt output generation on time-out

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Reset signal generation on time-out, if the interrupt from the previous time-out remains

unserviced by software

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Lock register to protect registers from being altered by runaway software

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Identification registers that uniquely identify the watchdog module. These can be used

by software to automatically configure itself.

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An APB slave allowing access to all registers

34.3

Functional description

Figure 115 shows a simplified block diagram of the watchdog module.

RM0319 Datasheet(PDF) 347 Page - STMicroelectronics