Use case: Configure EXTI line to specific GPIO pin

Sequence diagram

Configure EXTI line to specific GPIO pin (HAL1)

@startuml participant "Application" as App participant "GPIO" as GPIO participant "EXTI" as EXTI participant "NVIC" as NVIC App -> GPIO: HAL_GPIO_Init() App -> EXTI: HAL_EXTI_GetHandle() App -> EXTI: HAL_EXTI_RegisterCallback() App -> NVIC: HAL_NVIC_SetPriority() App -> NVIC: HAL_NVIC_EnableIRQ() EXTI -> App: GPIOx_Exti_FallingCb() @enduml

Code snippet

HAL1

HAL2 

GPIO_Init_TypeDef GPIO_InitStructure;
EXTI_HandleTypeDef EXTI_HandleStructure;

GPIO_InitStructure.Mode = GPIO_MODE_IT_FALLING;
GPIO_InitStructure.Pull = GPIO_NOPULL;
GPIO_InitStructure.Pin  = GPIO_PIN_YY;

HAL_GPIO_Init(GPIOx, &GPIO_InitStructure);

HAL_EXTI_GetHandle(&EXTI_HandleStructure, $EXTI_LINE_NUMBER$);

HAL_EXTI_RegisterCallback(&EXTI_HandleStructure,
                         HAL_EXTI_FALLING_CB_ID,
                         GPIOx_Exti_FallingCb);

HAL_NVIC_SetPriority(EXTI$EXTI_LINE_NUMBER$_IRQn, 2, 0);
HAL_NVIC_EnableIRQ(EXTI$EXTI_LINE_NUMBER$_IRQn);

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

hal_gpio_config_t GPIO_ConfigStructure;
hal_exti_handle_t hexti;
hal_exti_config_t EXTI_ConfigStructure;

GPIO_ConfigStructure.mode = HAL_GPIO_MODE_INPUT;
GPIO_ConfigStructure.pull = HAL_GPIO_PULL_NO;

HAL_GPIO_Init(HAL_GPIOx, HAL_GPIO_PIN_YY, &GPIO_ConfigStructure);

HAL_EXTI_Init(&hexti, HAL_EXTI_GPIO_YY);

EXTI_ConfigStructure.trigger  = HAL_EXTI_TRIGGER_FALLING;
EXTI_ConfigStructure.gpio_port = HAL_EXTI_GPIOX;
HAL_EXTI_SetConfig(&hexti, &EXTI_ConfigStructure);

HAL_EXTI_RegisterTriggerCallback(&hexti, GPIOx_Exti_FallingCb);

HAL_NVIC_SetPriority(EXTI$EXTI_LINE_NUMBER$_IRQn, 2, 0);
HAL_NVIC_EnableIRQ(EXTI$EXTI_LINE_NUMBER$_IRQn);

HAL_EXTI_Enable(&hexti, HAL_EXTI_MODE_INTERRUPT);

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

Key changes

  1. HAL2 uses an explicit EXTI handle init + config sequence (HAL_EXTI_Init / HAL_EXTI_SetConfig) instead of retrieving a handle via HAL_EXTI_GetHandle.

  2. Callback registration differs: HAL2 registers a trigger callback through the EXTI handle.

  3. EXTI start/enable is explicit in HAL2 (enable interrupt mode after configuration).