Watchdog

pchignon · ‎2005-09-28

Posted on September 28, 2005 at 12:43

Watchdog

pchignon · ‎2005-09-21

Posted on September 21, 2005 at 14:28

Hi,

Is it true that I cannot schedule the watchdog to 2 secondes approximatly with :

48MHz core frequency

APB2 divider to 2

48000000/2/256/65000 = 1,4 secondes.

Is there another mean to increase the watchdog value ?

Thanks,

Ludo

pchignon · ‎2005-09-22

Posted on September 22, 2005 at 15:19

Thank you,

Now, I try to disable the watchdog by applying a APB_SwResetConfig(APB2, ENABLE, WDG_Periph); But It doesn't work. Why?

PS: I know it is not a normal situation but I need it temporary

Thanks,

Ludo

pchignon · ‎2005-09-23

Posted on September 23, 2005 at 13:51

Ok,

Is it possible to use the watchdog and the LPWFI mode?

When you spoke about stop mode you would say all low power mode ?

Ludo,

pchignon · ‎2005-09-28

Posted on September 28, 2005 at 10:52

So,

How can I used watchdog and LPWFI mode ?

If my program stopped in LPWFI, it cannot refresh the wdg and it will reset.

Thanks,

Ludo

ben2 · ‎2005-09-28

Posted on September 28, 2005 at 11:45

I am using the WATCHDOG and lpwfi mode -

you need to set the RTC to exit LPWFI mode before the watchdog expires, reset the WATCHDOG, reset the alarm and go back to LPWFI mode.

This is far from ideal but does work. You can reset the WATCHDOG period to just over 8 minutes @ 32khz. Also you cant access the RTC @ 32khz which means you need to change to a higher clock freqeuncy first. This is the best you can get if you need low power and the watchdog.

Ideally I would prefer to use the STOP mode instead, but as I need to turn off the external oscillator to get the best power savings, I can't use STOP mode ( it needs to be active to come out of STOP mode). I think there are a few bad design points with this chip.

pchignon · ‎2005-09-28

Posted on September 28, 2005 at 12:43

Thank you very much,

I never suspected such a fact. But now, I understand much of my problems.

Thanks,

Ludo