Use case: Generate a software interrupt

Sequence diagram

Generate a software interrupt.

@startuml == Initialization == "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() "Application" -> EXTI: HAL_EXTI_SetConfigLine() == Register Callback == "Application" -> "EXTI": **HAL_EXTI_RegisterCallback(&hexti, &user_cb)** "EXTI" --> "Application": hal status: HAL_OK == Generate a software interrupt == "Application" -> "EXTI": **HAL_EXTI_GenerateSW(&hexti)** "EXTI" --> "Application": hal status: HAL_OK @enduml

Code snippet

HAL1

HAL2 

GPIO_InitTypeDef GPIO_InitStruct = {0};
/* EXTI handle instantiation */
EXTI_HandleTypeDef    *hexti;
/* EXTI Global Configuration structure */
EXTI_ConfigTypeDef *pExtiConfig;
/* 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_FALLING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

HAL_EXTI_GetHandle(&EXTI_HandleStructure, EXTI_LINE_13);

/* Setting the EXTI configuration structure */
pExtiConfig->Line       = EXTI_LINE_13;
pExtiConfig->Mode       = EXTI_MODE_INTERRUPT;

/* Setting new values to the EXTI configuration structure */
HAL_EXTI_SetConfigLine(&hexti, &pExtiConfig);

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);





/* Generate the software interrupt signal */
HAL_EXTI_GenerateSWI(&hexti);

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

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;
}

/* Generate the software interrupt signal on the selected EXTI line */
HAL_EXTI_GenerateSWI(&hexti);

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

Key changes

  1. HAL2 configures the EXTI line through HAL_EXTI_Init() and HAL_EXTI_SetConfig() and requires explicit enabling via HAL_EXTI_Enable().

  2. HAL2 uses HAL_EXTI_RegisterTriggerCallback() for trigger callbacks instead of the generic callback registration in HAL1.