Chapter 14: Watchdog timer and hardware reset
Description
The watchdog timer is a fail-safe against program crashes or processor lockups. It
has programmable timeout periods of 1 second to 2
16
seconds. The watchdog timer
can be enabled or disabled in Setup. The built-in INT17 software calls or an
operating system driver can be used to enable and set the timeout, strobe, and
disable the watchdog timer from your application. If the timer expires, it performs
a hardware reset.
Booting, power down, and strobing the watchdog timer
When the watchdog is enabled in Setup, it sets the timeout period for 300 seconds.
The BIOS will strobe the watchdog during the boot process and once more just
before booting is finished. The user’s application must then begin strobing. The
watchdog will continue until it is disabled or power down occurs.
If the watchdog is enabled in Setup and your operating system cannot load up
before the timer expires, your system could reset. Also, if you do not disable the
watchdog and your strobing application ends before power down you could again
reset. If these watchdog situations should occur, set the “S” switch, Switch 500
position 1, to Off and reboot. This causes the 5266 to boot using Setup defaults
(watchdog disabled). Enter Setup, then change and save the watchdog settings in
Setup.
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Содержание 5266
Страница 18: ...Figure 2 1 5266 component diagram top 18 ...
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Страница 20: ...Figure 2 3 5266 dimensions inches 20 ...
Страница 21: ...Figure 2 4 5266 dimensions mm 21 ...