stm32编程配置一个I/O为EXTI中断的步骤

配置一个I/O为EXTI中断的步骤：  

        GPIO_InitTypeDef GPIO_InitStructure;  

    EXTI_InitTypeDef EXTI_InitStructure;  

    NVIC_InitTypeDef NVIC_InitStructure;  

    //1.使能EXTIx线的时钟和第二功能AFIO时钟  

    RCC_APB2PeriphClockCmd( RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOA,ENABLE);  

//  NVIC_CONFIG();  

    //2.配置EXTIx线的中断优先级  

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);  

    NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;  

    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  

    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  

    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;  

    NVIC_Init(&NVIC_InitStructure);  

   //3.配置EXTIx中断线的I/O口  

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;  

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;  

    GPIO_Init(GPIOA,&GPIO_InitStructure);  

    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource3);//4.选定要配置为EXTI的I/O口线  

   //5.EXTIx中断线的工作模式的配置  

    EXTI_InitStructure.EXTI_Line = EXTI_Line3;  

    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;  

    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;  

    EXTI_InitStructure.EXTI_LineCmd = ENABLE;  

    EXTI_Init(&EXTI_InitStructure);