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);