WATCHDOG in Slow wait mode

didier · ‎2003-10-29

Posted on October 29, 2003 at 11:45

didier · ‎2003-10-13

Posted on October 13, 2003 at 13:39

I use a ST72F264G2M6.

I am configured with option byte to use software watchdog.

When i want to pass in wait mode (WFI instruction), i want to disable watchdog (bit WDGA=0, bit 7 of WDGCR) before activate WAIT mode and normally my watchdog don't wake-up the MCU. But my watchdog generate a reset and i leave the WAIT mode. I can't disable this watchdog, like if i was in case of Hardware Watchdog.

There is someone to help me please !

jatin · ‎2003-10-13

Posted on October 13, 2003 at 13:54

WDGA bit is cleared by default after reset. But if once set by the software can be cleared only by hardware after reset. So make sure that you have not set it after reset.

didier · ‎2003-10-27

Posted on October 27, 2003 at 10:40

Thanks for your quick answer.

But my problem is that when i ma in wait mode, i have a reset by the watchdog which wake up my CPU.

Is it normal or not ?

For me, when i am in wait mode, i can to control the wake-up of my CPU, so the watchdog must not have an effect on the wake-up.

Is this correct ?

Your help is welcome !!!

jatin · ‎2003-10-29

Posted on October 29, 2003 at 11:45

Wait mode has no effect on the watchdog. So it is normal if the CPU wakes up with the watchdog reset.

Watchdog is diasbled by default after reset. So, there is no chance for the watchdog reset unless it has been enabled after reset. But once it is enabled, it can be disabled only after reset.

I hope it is clear.

[ This message was edited by: Jatin on 29-10-2003 16:16 ]