User Guide CCM-BOOGIE • High Performance Core
TM
2 Duo 3U
CompactPCI
®
CPU Board
© EKF -26- ekf.com
Watchdog
An important reliability feature is the watchdog function, which is programmable by software. The
behaviour of the watchdog is defined within the PLD, which activates/deactivates the watchdog and
controls its time-out period. The time-out delay is adjustable in the steps 2, 10, 50 and 255 seconds.
After alerting the WD and programming the time-out value, the related software (e.g. application
program) must trigger the watchdog periodically. To simplify watchdog programming all watchdog
related functions can be done by calling service requests (software SMI's).
The watchdog is in a passive state after a system reset. There is no need to trigger it at boot time. The
watchdog is activated on the first trigger request. If the duration between two trigger requests
exceeds the programmed period, the watchdog times out and a full system reset will be generated.
The watchdog remains in the active state until the next system reset. There is no way to disable it once
it has been put on alert, whereas it is possible to reprogram its time-out value at any time.
