entering standby at WKUP pin is high

[hosoi]

Posted on October 01, 2015 at 09:30

hi

Please see the attached file.I use STM32L151QE PA0(WKUP1) for external wakeups from Standby Mode, CASE1 is wakeup OK, but CASE2  is wakeup NG.I know WKUP1=High  and entering standby, then the device will not wakeup?I'm mistake?Thanky

[Amel NASRI]

Posted on October 01, 2015 at 09:49

Hi hosoi.chitoshi,

What are CASE1 and CASE2?It should be better to provide a clear description of your issue based on code differences in the 2 cases.-Mayla-

[hosoi]

Posted on October 01, 2015 at 10:23

hi Mayla

sorry.CASE1 is the CPU goes into standby in wkup1 is Low, it will wake up at the rising edge of then wkup1.CASE2 is the CPU goes into standby in wkup1 is High, then the wkup1 to Low, and does not wake up the next rising edge.Thanky

[Amel NASRI]

Posted on October 07, 2015 at 12:20

Hi hosoi.chitoshi,

Sorry for this delayed reply.It seems that CPU doesn't re-enter standby mode after 1st wakeup in second case. Do you confirm this?-Mayla-

[hosoi]

Posted on October 08, 2015 at 05:57

hi Mayla

I made sure to be in Standby Mode using the following code in the state of WKUP1 is High.But, CPU can not return from Standby Mode, even if the WKUP1 signal is changed to High from Low. /* Enable WKUP pin 1 */ PWR_WakeUpPinCmd( PWR_WakeUpPin_1, ENABLE ); /* Clear WUF bit */ PWR->CR |= PWR_CR_CWUF; /* Enter STANDBY Mode */ PWR_EnterSTANDBYMode();image                        Enter STANDBY Mode                                          |                                         +            ------------------------+         +------------WKUP1                                    |          |               +------+        　　　　　　　　　　                  ----------------+-----------------------------CPU Mode     Active          | Standby                                    ----------------+-----------------------------                                                          +                                                            |                                            not return from Standby Mode Thanky