stm32外部中断实验

//外部中断0服务程序void EXTIX_Init(void){    EXTI_InitTypeDef EXTI_InitStructure;    NVIC_InitTypeDef NVIC_InitStructure;    KEY_Init();  // 按键端口初始化    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); //使能复用功能时钟    //GPIOE.2 中断线以及中断初始化配置   下降沿触发    GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource2);    EXTI_InitStructure.EXTI_Line=EXTI_Line2;    //KEY2    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;     EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;    EXTI_InitStructure.EXTI_LineCmd = ENABLE;    EXTI_Init(&EXTI_InitStructure);     //根据EXTI_InitStruct中指定的参数初始化外设EXTI寄存器   //GPIOE.3      中断线以及中断初始化配置 下降沿触发 //KEY1    GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource3);    EXTI_InitStructure.EXTI_Line=EXTI_Line3;    EXTI_Init(&EXTI_InitStructure);     //根据EXTI_InitStruct中指定的参数初始化外设EXTI寄存器   //GPIOE.4      中断线以及中断初始化配置  下降沿触发   //KEY0    GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource4);    EXTI_InitStructure.EXTI_Line=EXTI_Line4;    EXTI_Init(&EXTI_InitStructure);     //根据EXTI_InitStruct中指定的参数初始化外设EXTI寄存器   //GPIOA.0      中断线以及中断初始化配置 上升沿触发 PA0  WK_UP     GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0);     EXTI_InitStructure.EXTI_Line=EXTI_Line0;    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;    EXTI_Init(&EXTI_InitStructure);     //根据EXTI_InitStruct中指定的参数初始化外设EXTI寄存器    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;            //使能按键WK_UP所在的外部中断通道    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;    //抢占优先级2，     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;                   //子优先级3    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                             //使能外部中断通道    NVIC_Init(&NVIC_InitStructure);     NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;            //使能按键KEY2所在的外部中断通道    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;    //抢占优先级2，     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;                   //子优先级2    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                             //使能外部中断通道    NVIC_Init(&NVIC_InitStructure);    NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;            //使能按键KEY1所在的外部中断通道    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;    //抢占优先级2     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;                   //子优先级1     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                             //使能外部中断通道    NVIC_Init(&NVIC_InitStructure);       //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器    NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;            //使能按键KEY0所在的外部中断通道    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;    //抢占优先级2     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;                   //子优先级0     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                             //使能外部中断通道    NVIC_Init(&NVIC_InitStructure);       //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器}//外部中断0服务程序 void EXTI0_IRQHandler(void){    delay_ms(10);//消抖    if(WK_UP==1)         //WK_UP按键    {                        BEEP=!BEEP;     }    EXTI_ClearITPendingBit(EXTI_Line0); //清除LINE0上的中断标志位  }//外部中断2服务程序void EXTI2_IRQHandler(void){    delay_ms(10);//消抖    if(KEY2==0)   //按键KEY2    {        LED0=!LED0;    }            EXTI_ClearITPendingBit(EXTI_Line2);  //清除LINE2上的中断标志位  }//外部中断3服务程序void EXTI3_IRQHandler(void){    delay_ms(10);//消抖    if(KEY1==0)  //按键KEY1    {                        LED1=!LED1;    }            EXTI_ClearITPendingBit(EXTI_Line3);  //清除LINE3上的中断标志位  }void EXTI4_IRQHandler(void){    delay_ms(10);//消抖    if(KEY0==0)  //按键KEY0    {        LED0=!LED0;        LED1=!LED1;     }            EXTI_ClearITPendingBit(EXTI_Line4);  //清除LINE4上的中断标志位  }