Wake up

Posted on May 17, 2011 at 12:16

Hi all,

Can I choose external crystal 32.768khz for the timer?

I ask the questions because I want take micro in standby or stop mode and wake up with a timer interrupt and/or external interrupt (key) and/or rtc interrupt.

I don't use sleep mode (to many consumption).

Posted on May 17, 2011 at 12:16

Dear boubou ,

You can use the RTC Alarm to wake-up from both Standby an Stop Modes,

The RTC is either clocked by the LSE : 32.768KHz Quartz or using the LSI

(Internal Low speed RC). I hope this is useful for you.

Regards,

Posted on May 17, 2011 at 12:16

Boubou has mentioned two issues that I hope will be addressed in any new extra-low powered STM chips:

- the sleep current needs to be lower (especially for

- it would be great if either the RTC Seconds interrupt or the RTC Alarm interrupt could be used to wake the chip from STOP mode. At present only the RTC Alarm interrupt can be used to exit STOP mode. The Seconds interrupt provides a lower overhead (and more robust/safer) option for regular interrupts.

Posted on May 17, 2011 at 12:16

I have one question. Can I use LSI to generate RTC Alarm in STOP mode? I have problem with LSI. When I use LSE is OK(in libray exemple), but when I configure RTC to LSI oscilator I don't have any RTC Alarm event. I check LSI in Tamper pin and seem to be OK (LSI generator is working).

I use STM3210B_EVAL and I compile in Ride7

[ This message was edited by: dioda.fm on 22-12-2008 13:18 ]