【51单片机快速入门指南】3.1：配置外部中断触发方式和中断优先级

源码

stdint.h见【51单片机快速入门指南】1：基础知识和工程创建
中断知识见【51单片机快速入门指南】3：中断系统

将外部中断0和外部中断1均配置为下降沿触发，但外部中断1的优先级最高，外部中断0的优先级最低。

EXTI.c

#include <REGX52.H>
#include "intrins.h"
#include "stdint.h"
#include "EXTI.h"//定义LED管脚
sbit D1 = P2^0;
sbit D2 = P2^1;//定义独立按键控制脚
sbit K3 = P3^2;
sbit K4 = P3^3;void Delay20ms()		//@11.0592MHz
{unsigned char i, j;i = 36;j = 217;do{while (--j);} while (--i);
}//P3.2
void EXTI0_Callback() interrupt 0 //外部中断0中断函数
{Delay20ms();if(K3 == 0){D1 = !D1;while(K3 == 0);}
}//P3.3
void EXTI1_Callback() interrupt 2 //外部中断1中断函数
{Delay20ms();if(K4 == 0){D2 = !D2;	while(K4 == 0);}
}#if USE_EXTI2_EXTI3//P4.3void EXTI2_Callback() interrupt 6 //外部中断2中断函数{}//P4.2void EXTI3_Callback() interrupt 7 //外部中断3中断函数{}#endif#if EXTI_USE_STCsfr	IPH	= 0xb7;
#endifvoid EXTI0_Init(uint8_t EXTI_Type, uint8_t Priority)
{#if EXTI_USE_STCIPH &= ~1;IPH |= (2 & Priority) >> 1;#endifPX0  = (1 & Priority);		//设置中断优先级IT0  = EXTI_Type;			//触发方式EX0  = 1;					//打开INT0的中断允许EA   = 1;					//打开总中断
}void EXTI0_Switch(uint8_t Status)
{EX0  = Status;					
}void EXTI1_Init(uint8_t EXTI_Type, uint8_t Priority)
{#if EXTI_USE_STCIPH &= ~4;IPH |= (2 & Priority) << 1;#endifPX1  = (1 & Priority);		//设置中断优先级IT1	= EXTI_Type;			//触发方式EX1	= 1;					//打开INT1的中断允许EA	= 1;					//打开总中断
}void EXTI1_Switch(uint8_t Status)
{EX1  = Status;					
}#if USE_EXTI2_EXTI3sfr XICON = 0xc0;sbit PX2 = XICON^3;sbit EX2 = XICON^2;sbit IE2 = XICON^1;sbit IT2 = XICON^0;sbit PX3 = XICON^7;sbit EX3 = XICON^6;sbit IE3 = XICON^5;sbit IT3 = XICON^4;void EXTI2_Init(uint8_t EXTI_Type, uint8_t Priority){#if EXTI_USE_STCIPH &= ~0x40;IPH |= (2 & Priority) << 5;#endifPX2  = (1 & Priority);		//设置中断优先级IT2	= EXTI_Type;			//触发方式EX2	= 1;					//打开INT1的中断允许EA	= 1;					//打开总中断}void EXTI2_Switch(uint8_t Status){EX2  = Status;					}void EXTI3_Init(uint8_t EXTI_Type, uint8_t Priority){#if EXTI_USE_STCIPH &= ~0x80;IPH |= (2 & Priority) << 6;#endifPX3  = (1 & Priority);		//设置中断优先级IT3	= EXTI_Type;			//触发方式EX3	= 1;					//打开INT1的中断允许EA	= 1;					//打开总中断}void EXTI3_Switch(uint8_t Status){EX3  = Status;					}#endif

EXTI.h

#ifndef EXTI_H_
#define EXTI_H_#include "stdint.h"//使用外部中断2（P4.3）和外部中断3（P4.2） 貌似只有LQFP44封装的芯片才有，普通的DIP40芯片没有
#define USE_EXTI2_EXTI3 1//使用STC单片机的4级优先级
#define EXTI_USE_STC			1#define EXTI_LOW_LEVEL	0
#define EXTI_FALLING	1#if EXTI_USE_STC//STC单片机的4级优先级#define STC_EXTI_Priority_Lowest 	0#define STC_EXTI_Priority_Lower		1#define STC_EXTI_Priority_Higher	2#define STC_EXTI_Priority_Highest	3#endif//传统51单片机的2级优先级
#define EXTI_Priority_Low			0
#define EXTI_Priority_High			1void EXTI0_Init(uint8_t EXTI_Type, uint8_t Priority);
void EXTI0_Switch(uint8_t Status);void EXTI1_Init(uint8_t EXTI_Type, uint8_t Priority);
void EXTI1_Switch(uint8_t Status);#if USE_EXTI2_EXTI3void EXTI2_Init(uint8_t EXTI_Type, uint8_t Priority);void EXTI2_Switch(uint8_t Status);void EXTI3_Init(uint8_t EXTI_Type, uint8_t Priority);void EXTI3_Switch(uint8_t Status);#endif#endif

main.c

#include <REGX52.H>
#include "intrins.h"
#include "stdint.h"
#include "EXTI.h"void main(void)
{	EXTI0_Init(EXTI_FALLING, STC_EXTI_Priority_Lowest);EXTI1_Init(EXTI_FALLING, STC_EXTI_Priority_Highest);while(1){}
}