STM32外部中断之二

1配置中断

1、 分配中断向量表：

/* Set the Vector Table base location at 0x20000000 */

NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);

2、 设置中断优先级：

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); //设置中断优先级

3、 初始化外部中断：

/*允许EXTI4中断 */

       NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQChannel; //中断通道

       NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PreemptionPriorityValue;//强占优先级

       NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //次优先级

       NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //通道中断使能

       NVIC_Init(&NVIC_InitStructure);       //初始化中断

注意：如果我们配置的外部针脚为PA4，或PB4，或PC4，PD4等，那么采用的外部中断也必须是EXTI4，同样，如果外部中断针脚是PA1，PB1，PC1，PD1 那么中断就要用EXTI1，其他类推。

2配置GPIO针脚作为外部中断的触发事件

1、 选择IO针脚

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;

注意，如果的针脚是端口的4号针脚，配置的中断一定是EXTI4

2、 配置针脚为输入

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

3、 初始化针脚

GPIO_Init(GPIOD,&GPIO_InitStructure);

3配置EXTI线，使中断线和IO针脚线连接上

1、 将EXTI线连接到IO端口上

将EXTI线4连接到端口GPIOD的第4个针脚上

       GPIO_EXTILineConfig(GPIO_PortSourceGPIOD,GPIO_PinSource4);

       注意：如果配置的针脚是4号，那么参数必须是GPIO_PinSource4

              如果配置的针脚是3号，那么参数必须是GPIO_PinSource3

2、配置中断边沿

       /*配置EXTI线0上出现下降沿，则产生中断*/

       EXTI_InitStructure.EXTI_Line = EXTI_Line4;

       注意：如果配置的4号针脚，那么EXTI_Line4是必须的

       EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

       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);                 //初始化中断

       EXTI_GenerateSWInterrupt(EXTI_Line4);         //EXTI_Line4中断允许

到此中断配置完成，可以写中断处理函数。

举例：

配置函数

/*************************************************************************

* 函数名      NVIC_Configration

* 描述          配置各个中断寄存器

* 输入           无

* 输出           无

* 返回值       无

****************************************************************************/

void NVIC_Configration(void)

{

        NVIC_InitTypeDef NVIC_InitStructure;

//#ifdef VECT_TAB_RAM

      /* Set the Vector Table base location at 0x20000000 */

      NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);

//#else /* VECT_TAB_FLASH */

      /* Set the Vector Table base location at 0x08000000 */

      //NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);  

//#endif  

       NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); //设置中断优先级

       /*允许EXTI4中断 */

       NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQChannel;

       NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PreemptionPriorityValue;

       NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

       NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

       NVIC_Init(&NVIC_InitStructure);      

       /*允许EXTI9中断*/

       NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQChannel;

       NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

       NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;

       NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

       NVIC_Init(&NVIC_InitStructure);      

       /*配置SysTick处理优先级：优先级以及子优先级*/

}

/************************************************************************

* 函数名       :GPIO_Configuration(void)

* 描述           :配置TIM2阵脚

* 输入           ：无

* 输出      ：无

* 返回           ：无

************************************************************************/

void GPIO_Configuration(void){

/*    GPIO_InitTypeDef GPIO_InitStructure;

       GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3;

       GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

       GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

       GPIO_Init(GPIOA,&GPIO_InitStructure); */

       GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All;

       GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

       GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;

       GPIO_Init(GPIOC,&GPIO_InitStructure);

       /*配置GPIOD的第一个管角为浮动输入*/

       GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;

       GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

       GPIO_Init(GPIOD,&GPIO_InitStructure);

       /*配置GPIOB的第9个管脚为浮动输入*/

       GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;

       GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

       GPIO_Init(GPIOB,&GPIO_InitStructure);

}

/**************************************************************

* 函数           SysTick_Configuration

* 描述          设置SysTick

* 输入           无

* 输出          无

* 返回值      无

***************************************************************/

void SysTick_Configuration(void)

{

      /*配置 HCLK 时钟做为SysTick 时钟源*/

       SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8); //系统时钟8分频 72MHz

       NVIC_SystemHandlerPriorityConfig(SystemHandler_SysTick, 8,2);

       /*SysTick Interrupt each 1000Hz with HCLK equal to 72MHz*/

       SysTick_SetReload(9000);//中断周期1ms

       /*Enable the SysTick Interrupt */

       SysTick_ITConfig(ENABLE);//打开中断          

       SysTick_CounterCmd(SysTick_Counter_Enable);

       SysTick_CounterCmd(SysTick_Counter_Clear);                

}

/******************************************************************************

* 函数名       EXTI_Configuration

* 描述           配置EXTI线

* 输入           无

* 输出           无

* 返回值       无

******************************************************************************/

void EXTI_Configuration(void){

       /*将EXTI线0连接到PA0*/

       GPIO_EXTILineConfig(GPIO_PortSourceGPIOD,GPIO_PinSource4);

       /*配置EXTI线0上出现下降沿，则产生中断*/

       EXTI_InitStructure.EXTI_Line = EXTI_Line4;

       EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

       EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

       EXTI_InitStructure.EXTI_LineCmd = ENABLE;

       EXTI_Init(&EXTI_InitStructure);

       EXTI_GenerateSWInterrupt(EXTI_Line4);

       /*将EXTI线9连接到PB9上*/

       GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource9);

       /*将EXTI线9上出现下降沿产生中断*/

       EXTI_InitStructure.EXTI_Line = EXTI_Line9;

       EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

       EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

       EXTI_InitStructure.EXTI_LineCmd = ENABLE;

       EXTI_Init(&EXTI_InitStructure);

       EXTI_GenerateSWInterrupt(EXTI_Line9);       

}

中断函数：

void EXTI4_IRQHandler(void)

{

       if(EXTI_GetITStatus(EXTI_Line4)!= RESET){

              EXTI_ClearITPendingBit(EXTI_Line4);

              if(Ledflag == 0){

                     Ledflag = 1;

                     GPIOC->ODR |= 0X00000080;

              }

              else{

                     Ledflag = 0;          

                     GPIOC->ODR &= 0XFFFFFF7F;

              }

       }

}

注:时钟设置的时候最好加上这句：

RCCRCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); // 使能AFIO时钟