WUF flag when exiting Standby

[Akoli.2]

Hello.

STM32G070C

I'm having some issues with the WUF flag when exiting Standby. Exit mode is set to WKUP1 (PA0).

I poll the register after exiting standby and in the PWR->SR1 register, the SBF flag is set, but the WUF1 flag is cleared.

I also noticed an error in RM0454 Rev 5, on page 103 in the description of exiting the mode, it says that the SBF flag is in the PWR-> CR3 register, but it is in the SR1 register.

Code example.

void sleep()

{

RCC->APBENR1 |= RCC_APBENR1_PWREN ;

PWR->CR3 = 0x8001;

PWR->CR4 = 0x1;

PWR->CR1 &=~ PWR_CR1_LPMS_Msk;

PWR->CR1 |= 1 | (1 << 1);

PWR->SCR = PWR_SCR_CSBF | PWR_SCR_CWUF1;

SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;

__SEV();

__WFE();

asm("nop");

__WFE();

asm("nop");

}

int main()

{

ClockInit();

_delay_init();

RCC->APBENR1 |= RCC_APBENR1_PWREN ;

if((PWR->SR1 & (PWR_SR1_SBF)) != 0)

{

// I get here

if((PWR->SR1& (PWR_SR1_WUF1)) != 0)

{

// I don't get here

[Sarra.S]

Hello @Community member​,

Are you sure that you're exiting standby mode?

SBF is set which means the device entered standby mode but WUF is cleared means probably you didn't exit the standby mode.

A power-on reset occurs when exiting from standby, all registers [except the ones in the backup domain] are reset, this includes the PWR_SR1 register. The WUF1 flag is only set after exiting standby modes.

I also noticed an error in RM0454 Rev 5, on page 103 in the description of exiting the mode

>> Thank you for reporting the typo, it is tracked internally with ticket number: 154097 (This is an internal tracking number and is not accessible or usable by customers).

[Akoli.2 · Accepted solution]

I figured out the problem today, but did not have time to write here. The problem was that I was parsing the debug data incorrectly. The WUF1 flag is set. I also checked WUF2, this is also set.

thanks for support.

[Piranha]

https://community.st.com/s/question/0D53W00001bnh8dSAA/how-to-enter-standby-or-shutdown-mode-on-stm32