原创 外部中断配置

2010-3-24 15:53 1874 10 10 分类: MCU/ 嵌入式
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PC4PD4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PA1PB1PC1PD1 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、  EXTI线连接到IO端口上
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          
* 输出          
* 返回值      
****************************************************************************/
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          
* 输出         
* 返回值     
***************************************************************/
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          
* 输出          
* 返回值      
******************************************************************************/
void EXTI_Configuration(void){
 
       /*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);
      
       /*EXTI线9连接到PB9*/
       GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource9);
       /*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;
              }
       }
}
转:openorg http://www.openorg.cn/read-htm-tid-624.html

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