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Associate II
July 19, 2026
Question

STM32L051 sometime do not exit from stop mode.

  • July 19, 2026
  • 2 replies
  • 66 views

Post edited by ST moderator for the code. 

Hi,
I have a pre-production batch of about 80 STM32L051 custom boards.
Under certain circumstances, the microcontroller goes into sleep mode and waits for an IRQ to restart.
Of these 80 boards, about 10 randomly, after going into sleep mode, don't restart (until a reset).
This is the code I use:

__HAL_GPIO_EXTI_CLEAR_IT( VIB_SENS_MAIN_Pin);
__HAL_GPIO_EXTI_CLEAR_IT( VIB_SENS_BACKUP_Pin);

NVIC_EnableIRQ( EXTI4_15_IRQn);
HAL_COMP_Stop_IT( &hcomp1);
HAL_COMP_Stop_IT( &hcomp2);

__disable_irq();
__HAL_PWR_CLEAR_FLAG( PWR_FLAG_WU);
__HAL_GPIO_EXTI_CLEAR_IT( VIB_SENS_MAIN_Pin);
__HAL_GPIO_EXTI_CLEAR_IT( VIB_SENS_BACKUP_Pin);
__HAL_COMP_COMP1_EXTI_CLEAR_FLAG();
__HAL_COMP_COMP2_EXTI_CLEAR_FLAG();
delay_us( 5);

HAL_SuspendTick();
HAL_PWR_EnterSTOPMode( PWR_LOWPOWERREGULATOR_ON, PWR_SLEEPENTRY_WFI);

HAL_NVIC_SystemReset();

What did I do wrong?

Thanks for the suggestion.

 

2 replies

UfoitAuthor
Associate II
July 19, 2026

Forget about this.
It looks like a hardware design issue that I need to have re-checked.
Thanks.

mƎALLEm
ST Technical Moderator
July 20, 2026

Hello ​@Ufoit ,

In next time please use code button to paste a code :

When you started this post, did you see this pop-up?

PS: I’ve edited your post.

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