[STM32F103]外部中断

① 初始化IO口为输入。

GPIO_Init();

② 开启IO口复用时钟。

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);

③ 设置IO口与中断线的映射关系。

void GPIO_EXTILineConfig();

④ 初始化线上中断，设置触发条件等。

EXTI_Init();

⑤ 配置中断分组（NVIC），并使能中断。

NVIC_Init();

⑥ 编写中断服务函数。

EXTIx_IRQHandler();

⑦ 清除中断标志位

EXTI_ClearITPendingBit();

 

源码：

 void EXTIX_Init(void)
 {
        EXTI_InitTypeDef EXTI_InitStructure;
      NVIC_InitTypeDef NVIC_InitStructure;

     KEY_Init();     //    °´¼ü¶Ë¿Ú³õʼ»¯

       RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);    

    //GPIOE.3      ÖжÏÏßÒÔ¼°Öжϳõʼ»¯ÅäÖà ϽµÑØ´¥·¢ //KEY1
       GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource3);
       EXTI_InitStructure.EXTI_Line=EXTI_Line3;
       EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
       EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
       EXTI_Init(&EXTI_InitStructure);          //¸ù¾ÝEXTI_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèEXTI¼Ä´æÆ÷

    //GPIOE.4      ÖжÏÏßÒÔ¼°Öжϳõʼ»¯ÅäÖà  Ï½µÑØ´¥·¢    //KEY0
       GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource4);
       EXTI_InitStructure.EXTI_Line=EXTI_Line4;
       EXTI_Init(&EXTI_InitStructure);          //¸ù¾ÝEXTI_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèEXTI¼Ä´æÆ÷

    //GPIOA.0      ÖжÏÏßÒÔ¼°Öжϳõʼ»¯ÅäÖà ÉÏÉýÑØ´¥·¢ 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);        //¸ù¾ÝEXTI_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèEXTI¼Ä´æÆ÷

       NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;            //ʹÄÜ°´¼üWK_UPËùÔÚµÄÍⲿÖжÏͨµÀ
       NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;    //ÇÀÕ¼ÓÅÏȼ¶2£¬
       NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;                    //×ÓÓÅÏȼ¶3
       NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                                //ʹÄÜÍⲿÖжÏͨµÀ
       NVIC_Init(&NVIC_InitStructure); 

       NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;            //ʹÄÜ°´¼üKEY1ËùÔÚµÄÍⲿÖжÏͨµÀ
       NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;    //ÇÀÕ¼ÓÅÏȼ¶2
       NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;                    //×ÓÓÅÏȼ¶1
       NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                                //ʹÄÜÍⲿÖжÏͨµÀ
       NVIC_Init(&NVIC_InitStructure);        //¸ù¾ÝNVIC_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèNVIC¼Ä´æÆ÷

       NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;            //ʹÄÜ°´¼üKEY0ËùÔÚµÄÍⲿÖжÏͨµÀ
       NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;    //ÇÀÕ¼ÓÅÏȼ¶2
       NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;                    //×ÓÓÅÏȼ¶0
       NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                                //ʹÄÜÍⲿÖжÏͨµÀ
       NVIC_Init(&NVIC_InitStructure);        //¸ù¾ÝNVIC_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèNVIC¼Ä´æÆ÷

 }

 //ÍⲿÖжÏ0·þÎñ³ÌÐò
 void EXTI0_IRQHandler(void)
 {
     delay_ms();//Ïû¶¶
     if(WK_UP==)          //WK_UP°´¼ü
     {
         BEEP=!BEEP;
     }
     EXTI_ClearITPendingBit(EXTI_Line0); //Çå³ýLINE0ÉϵÄÖжϱê־λ
 }

 //ÍⲿÖжÏ3·þÎñ³ÌÐò
 void EXTI3_IRQHandler(void)
 {
     delay_ms();//Ïû¶¶
     if(KEY1==)     //°´¼üKEY1
     {
         LED1=!LED1;
     }
     EXTI_ClearITPendingBit(EXTI_Line3);  //Çå³ýLINE3ÉϵÄÖжϱê־λ
 }

 void EXTI4_IRQHandler(void)
 {
     delay_ms();//Ïû¶¶
     if(KEY0==)     //°´¼üKEY0
     {
         LED0=!LED0;
         LED1=!LED1;
     }
     EXTI_ClearITPendingBit(EXTI_Line4);  //Çå³ýLINE4ÉϵÄÖжϱê־λ
 }