STM32U5 STOP2 with FreeRTOS

[caiChangKun]

What should I pay attention to when I use stm32u5 FreeRtos stop2,
When exiting stop2, do the relevant i2c spi adc uart peripherals need to be reinitialized?
Is the value retained?
Is there a routine for FreeRtos stop2?

void Bsp_PowerManage_enter_stop_mode(void)
{
if ((device_state_info.stimulate_state) || (device_state_info.device_ota)) {
return;
}
osKernelLock(); /
while (__HAL_UART_GET_FLAG(&hlpuart1, USART_ISR_BUSY));
while (__HAL_UART_GET_FLAG(&hlpuart1, USART_ISR_REACK) == RESET);
__HAL_RCC_LPUART1_CLKAM_ENABLE();
__HAL_RCC_LPTIM1_CLKAM_ENABLE();
HAL_UARTEx_EnableStopMode(&hlpuart1);
device_lowpower_state.stop_mode_state = 1;
HAL_SuspendTick(); // 
#if Bsp_IWDG
if (HAL_LPTIM_TimeOut_Start_IT(&hlptim1, 61438) != HAL_OK)
{
Error_Handler();
}
#endif
HAL_PWREx_EnterSTOP2Mode(PWR_STOPENTRY_WFI);
SystemClock_Config();
HAL_InitTick(TICK_INT_PRIORITY)

if (!__HAL_PWR_GET_FLAG(PWR_FLAG_STOPF)) Error_Handler();
__HAL_PWR_CLEAR_FLAG(PWR_FLAG_STOPF);
if (__HAL_PWR_GET_FLAG(PWR_FLAG_STOPF)) Error_Handler();


#if Bsp_IWDG
HAL_LPTIM_TimeOut_Stop_IT(&hlptim1);
#endif
HAL_UARTEx_DisableStopMode(&hlpuart1);
HAL_UARTEx_ReceiveToIdle_IT(&hlpuart1, uart_recv_data.buf, 512);
device_lowpower_state.stop_mode_state = 0;
osKernelUnlock();
Function_Open_PowerManageTimer();// Open FreeRtos TIME

}

---

Edited to apply source code formatting - please see How to insert source code for future reference.

[Saket_Om]

Hello @caiChangKun 

Several peripheral support the autonomous mode and can run in STOP mode without CPU wakeup. Please refer to the reference manual: 

So you don't need to reinitialize these peripheral. 

Below is typical sequence for entering and exiting STOP2 with FreeRTOS:

void Enter_Stop2_Mode(void)
{
    // 1. Prepare peripherals (stop ongoing transfers, etc.)
    // 2. Lock the RTOS kernel
    osKernelLock();

    // 3. Suspend SysTick
    HAL_SuspendTick();

    // 4. Enter STOP2 mode
    HAL_PWREx_EnterSTOP2Mode(PWR_STOPENTRY_WFI);

    // 5. Upon wakeup, reconfigure system clock
    SystemClock_Config();

    // 6. Resume SysTick
    HAL_ResumeTick();

    // 8. Unlock the RTOS kernel
    osKernelUnlock();
}