stm32中断优先级管理与外部中断编程

中断优先级管理

外部中断编程

官方示例程序

exti.h

#ifndef __EXTI_H
#define __EXIT_H     
#include "sys.h"
                          
//////////////////////////////////////////////////////////////////////////////////        
void EXTIX_Init(void);//外部中断初始化                                 
#endif

代码

exti.c

#include "exti.h"
#include "led.h"
#include "key.h"
#include "delay.h"
#include "usart.h"
#include "beep.h"

//////////////////////////////////////////////////////////////////////////////////     

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  
}

代码

main.c

#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include "exti.h"
#include "beep.h"



 int main(void)
 {        
 
    delay_init();             //延时函数初始化      
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //设置NVIC中断分组2:2位抢占优先级，2位响应优先级
    uart_init(115200);     //串口初始化为115200
     LED_Init();                  //初始化与LED连接的硬件接口
    BEEP_Init();             //初始化蜂鸣器端口
    KEY_Init();             //初始化与按键连接的硬件接口
    EXTIX_Init();             //外部中断初始化
    LED0=0;                    //点亮LED0
    while(1)
    {        
        printf("OK
");    
        delay_ms(1000);      
    }
 }

代码