Use case: Wake-up from stop mode with EXTI interrupt (WFI)

Sequence diagram

Wake-up from stop mode with EXTI interrupt (WFI).

@startuml !pragma teoz true == Prerequisites == "Application" -> GPIO: HAL_GPIO_Init() "Application" -> EXTI: HAL_EXTI_GetHandle() "Application" -> EXTI: HAL_EXTI_RegisterCallback() "Application" -> NVIC: HAL_NVIC_SetPriority() "Application" -> NVIC: HAL_NVIC_EnableIRQ() == Enter STOP Mode == "Application" -> "PWR": **HAL_PWR_EnterSTOP0Mode( PWR_STOPENTRY_WFI);** "PWR" --> "Application": MCU enters Stop Mode {start} "Application" <- "Application" ... ... ... {end} "Application" -> "Application" {start} <-> {end}: <i>MCU in Stop Mode == System wake-up from stop mode == "EXTI IRQHandler" <- : Interrupt "EXTI IRQHandler" --> "EXTI": "**HAL_EXTI IRQHandler(&hexti)**" "EXTI" -> "PWR": Wake-up the CPU from Stop Mode "EXTI" -> "Application": "**FallingCallback()** / **RisingCallback()**" @enduml

Code snippet

HAL1

HAL2 

/* */

static void MX_GPIO_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};

    /* GPIO Ports Clock Enable */
    __HAL_RCC_GPIOC_CLK_ENABLE();


    /*Configure GPIO pin : GPIO_PIN_13 */
    GPIO_InitStruct.Pin = GPIO_PIN_13;
    GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);


    HAL_EXTI_GetHandle(&EXTI_HandleStructure, EXTI_LINE_13);









    HAL_EXTI_RegisterCallback(&EXTI_HandleStructure,
                              HAL_EXTI_FALLING_CB_ID,
                              GPIOC_Exti_FallingCb);
  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0, 0);


  HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
}






void EXTI13_IRQHandler(void)
{
  HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_13);
}

















/* Enter STOP 0 mode */
HAL_PWREx_EnterSTOPMode(PWR_STOPENTRY_WFI);


static void GPIOx_Exti_FallingCb(void)
{
  (...)
}

static hal_exti_handle_t exti_line13_handle;

void *exti_init(void)
{
    /* GPIOC GPIO_PIN_13 Clock activation */
    hal_gpio_config_t config_gpio;
    hal_exti_config_t exti_config;

    MX_EXAMPLE_GPIO_TRIGGER_CLK_ENABLE();

    config_gpio.mode         = HAL_GPIO_MODE_INPUT;
    config_gpio.pull         = HAL_GPIO_PULL_NO;
    config_gpio.output_type  = HAL_GPIO_OUTPUT_OPENDRAIN;
    config_gpio.speed        = HAL_GPIO_SPEED_FREQ_VERY_HIGH;
    HAL_GPIO_Init(HAL_GPIOC, HAL_GPIO_PIN_13, &config_gpio);

    if (HAL_EXTI_Init(&exti_line13_handle, HAL_EXTI_LINE_13) != HAL_OK)
    {
        return NULL;
    }

    exti_config.trigger = HAL_EXTI_TRIGGER_FALLING;
    exti_config.gpio_port = HAL_EXTI_GPIOC;

    HAL_EXTI_SetConfig(&exti_line13_handle, &exti_config);


    HAL_EXTI_RegisterTriggerCallback(&hexti,
                                     GPIOC_Exti_FallingCb);


    HAL_CORTEX_NVIC_SetPriority(MX_EXAMPLE_EXTI_TRIGGER_EXTI_IRQ_N,
                                HAL_CORTEX_NVIC_PREEMP_PRIORITY_0,
                                HAL_CORTEX_NVIC_SUB_PRIORITY_0);
    HAL_CORTEX_NVIC_EnableIRQ(MX_EXAMPLE_EXTI_TRIGGER_EXTI_IRQ_N);

    HAL_EXTI_Enable(&hexti, HAL_EXTI_MODE_INTERRUPT);

    return (void *)&exti_line13_handle;
}

void EXTI13_IRQHandler(void)
{
  HAL_EXTI_IRQHandler(&exti_line13_handle);
}

uint32_t mx_power_config(void)
{
    uint32_t config_status = 0;

    config_status = HAL_PWR_SetMainRegulatorSupply(HAL_PWR_MAIN_REGULATOR_SMPS_SUPPLY);

    HAL_PWR_SetMainRegulatorStartupMode(HAL_PWR_MAIN_REGULATOR_FAST_STARTUP);

    HAL_PWR_SetCoreSleepMode(HAL_PWR_CORE_DEEP_SLEEP);

    return config_status;
}


    /* Enter STOP0 Mode */
    HAL_PWR_EnterStopMode(HAL_PWR_LOW_PWR_MODE_WFI,
                          HAL_PWR_STOP0_MODE);

static void GPIOx_Exti_FallingCb(void)
{
  (...)
}

Key changes

  1. HAL2 uses explicit EXTI initialization and configuration (HAL_EXTI_Init() + HAL_EXTI_SetConfig()) instead of handle retrieval.

  2. HAL2 requires explicit line enabling using HAL_EXTI_Enable() before entering stop mode.