STM32F107 can't correctly wakeup from standby mode

[ASerg.1]

I'm trying to use the standby mode of STM32F and waking it up by WKUP (PA0) pin.

Going to standby seems OK, power consumption goes to 4 uA.

If I reset MCU with RESET pin, it starts normally: after 250 ms delay it goes to sleep and consumes 4 uA

https://i.stack.imgur.com/nDM6f.png

But if I wake it up with WKUP pin it behaves strangely: consumption stays on a "run" level and I see cycles off my 250 delay, MCU keeps restarting instead of going to sleep.

https://i.stack.imgur.com/KYPqM.png

My code is really simple:

#include <stm32f1xx_hal.h>
 
 
#ifdef __cplusplus
extern "C"
#endif
void SysTick_Handler(void)
{
	HAL_IncTick();
	HAL_SYSTICK_IRQHandler();
}
 
void Error_Handler()
{
	__asm("bkpt 255");
	__asm("bx lr");
}
 
void SystemClock_Config(void)
{
	RCC_OscInitTypeDef RCC_OscInitStruct = { 0 };
	RCC_ClkInitTypeDef RCC_ClkInitStruct = { 0 };
 
	__HAL_RCC_AFIO_CLK_ENABLE();
	__HAL_RCC_PWR_CLK_ENABLE();
	
	/** Initializes the RCC Oscillators according to the specified parameters
	* in the RCC_OscInitTypeDef structure.
	*/
	RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_LSI;
	RCC_OscInitStruct.HSIState = RCC_HSI_ON;
	RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
	RCC_OscInitStruct.LSIState = RCC_LSI_ON;
	RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
	RCC_OscInitStruct.PLL2.PLL2State = RCC_PLL_NONE;
	if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
	{
		Error_Handler();
	}
	/** Initializes the CPU, AHB and APB buses clocks
	*/
	RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
	              | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
	RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
	RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
	RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
	RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 
	if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
	{
		Error_Handler();
	}
 
	/** Configure the Systick interrupt time
	*/
	__HAL_RCC_PLLI2S_ENABLE();
}
 
int main(void)
{
	HAL_Init();
	
	SystemClock_Config();
 
	__HAL_AFIO_REMAP_SWJ_NOJTAG();
	HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1);
 
	HAL_Delay(250);
	
	HAL_PWR_EnterSTANDBYMode();	
}

[ASerg.1 · Accepted solution]

Found a solution in errata sheet and with a help of the internet:

int main(void)
{
	HAL_Init();
	
	SystemClock_Config();
 
	__HAL_AFIO_REMAP_SWJ_NOJTAG();
	HAL_PWR_DisableWakeUpPin(PWR_WAKEUP_PIN1);
	
	PWR->CR |= PWR_CR_CWUF;
	if (__HAL_PWR_GET_FLAG(PWR_FLAG_SB) != RESET) {
		/* System resumed from STANDBY mode */
		__HAL_PWR_CLEAR_FLAG(PWR_FLAG_SB); 
		/* Clear StandBy flag */
		__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU); 
		/* Clear Wakeup flag */
	}
	
	HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1);
 
	HAL_Delay(250);
	
	HAL_PWR_EnterSTANDBYMode();	
}