Hi
My name is Jonah and I’m working on STM32L031K4U6 .
My device needs to go to standby, wake up via PA2(WKUP3) or RTC wakeup
I follow Doc RM0377 page 869 (to update PRER) , page 870(to update CR)
If I write : RTC->CR =0x00000404U; ( WUTE=1 but WUTIE=0)
then RTC doesn’t wakeup ,still , WKUP3 does wakeup.
If I write : RTC->CR =0x00004404U; (WUTE=1 but WUTIE=1) then:
If WKUP3 occurs before 1st RTC wakeup than wakeup happens, yet RTC wakeup doesn’t.
Moreover- if WKUP3 occur after RTC wakeup should have (but doesn’t) then no wakeup is achieved (anymore/ever)
I want to assume that the wakeup from standby is an event (WFE) and not an interrupt- although : I did try to activate the NVIC –still didn’t work.
If I write : RTC->CR =0x00604404U; (Wakeup output enabled) then RTC wakeup works, yet
PA2(WKUP3) doesn’t.
PA2(external pullup) goes low in a strange way- I can’t make out (goes low AFTER the wakeup was produced)
//------------------------------------------------------------------
PWR->CSR=0x400; // WKUP3
RCC->CSR =0x00020001U; //p209 LSI on , feeding RTC (on)
RCC->CSR =0x00060001U; //p209 LSI on , feeding RTC (on)
RTC->WPR =0x000000CAU; RTC->WPR =0x00000053U; //p573 unlock write RTC regs
//exp p869
for(RTC->ISR=0x80;!(RTC->ISR & 0x40);); //p566
RTC->PRER =0x001C0070U; //p569 prescalar p548 100mSec (28+1)*(112+1)/32768=0.1Sec
RTC->ISR=0;
//exp p870
for(RTC->CR&=~0x400;!(RTC->ISR & 4);); //p551
RTC->WUTR=ep.small_WK; //p570
RTC->CR =0x00604404U; //?????? p563 RTC/PRER for wakeup +p159
RTC->WPR =0x000000FEU; RTC->WPR =0x00000064U; //p534 lock write RTC regs
NVIC->ICPR[0]=0xFFFFFFFF; //pp89
PWR->CR =0xF05|0xA; //p161 reset SBF
SCB->SCR=0x04; //pp97
__WFE();
//-------------------------------------------------------------------
Does anybody know – what am I doing wrong?
Thanks
Jonah
