exit.h #ifndef __EXTI_H #define __EXTI_H #include "stm32f4xx.h" void Exti_PA0_Init(void); #endif exit.c #include "exti.h" /********************************* 引脚说明 KEY0 连接PA0（EXTIO），选择下降沿触发 **********************************/ void Exti_PA0_Init(void) { EXTI_InitTypeDef EXTI_InitStructure; GPIO_InitTypeDef GPIO_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; //使能SYSCFG及GPIOA时钟 /* Enable GPIOA clock */ RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); /* Enable SYSCFG clock */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); /* Configure PA0 pin as input floating */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //引脚0 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN; //输出模式 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉 GPIO_Init(GPIOA, &GPIO_InitStructure); /* Connect EXTI Line0 to PA0 pin */ //PA0--EXTI0 SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0); /* Configure EXTI Line0 */ EXTI_InitStructure.EXTI_Line = EXTI_Line0; //中断线0 EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; //中断模式 EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; //下降沿触发 EXTI_InitStructure.EXTI_LineCmd = ENABLE; //中断线使能 EXTI_Init(&EXTI_InitStructure); /* Enable and set EXTI Line0 Interrupt to the lowest priority */ NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; //中断通道 中断在stm32f4xx.h中查找 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01; //抢占优先级 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01; //响应优先级 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //通道使能 NVIC_Init(&NVIC_InitStructure); } /************************************************* 1.STM32的中断服务函数在startup_stm32f40_41xxx.s中查找 如果在查找不到对应的函数，说明它是普通函数。 2.中断服务函数模型：void 中断服务函数名(void) 3.中断服务函数不需要调用，满足条件CPU自动去执行 **************************************************/ void EXTI0_IRQHandler(void) { //判断中断标志位是否置1 if(EXTI_GetITStatus(EXTI_Line0) == SET) { //非法地址写值 程序卡死（跑飞） *((volatile unsigned int *)(0xC0000000)) = 0x66; //清空标志位 EXTI_ClearITPendingBit(EXTI_Line0); } }