AN421 Datasheet, PDF (1/11 Pages) STMicroelectronics – In real time applications

AN421
Application note
Stack overflow detection using the ST9 timer/watchdog
1
Introduction
In real time applications, implementation of software protection is not always easy, but it is
needed to reach a high level of security against software malfunction. This is particularly
true for on-board applications in noisy environments, such as automotive, power meter or
industrial applications.
To help avoid un-controlled operations and damage to real time systems due to any possible
disturbance of the ST9 microcontroller core and I/O ports, a special peripheral acting as a
watchdog is available on all ST9 family members: the Timer/Watchdog.
The periodic restarting of the Timer/Watchdog by the application software, associated with
the automatic detection of any stack overflow, provide enhanced protection to real time
application software.
This application note shows how to detect stack overflow by using the Timer/Watchdog in
watchdog mode.
November 2011
Doc ID 2476 Rev 2
1/11
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