关于mini2440的一个裸机程序——LED与按键中断

 

/* *File : main.c *Description: When you press the key, *  the LED will show the key_value of key by the binary  *  and produce the buzzer. *Author: Cong *Copyright: Cong * * *History *--------------------- *Rev:0.0 *Date:2011/11/26 *Creat. *-------------------- * * */  //--------------------Include Files------------------------------------//#include "2440addr.h"#include "2440slib.h"//---------------------Define Valurable-------------------------------//#define GLOBAL_CLK 1#define LED1_ON   ~(1<<5)#define LED2_ON   ~(1<<6)#define LED3_ON   ~(1<<7)#define LED4_ON   ~(1<<8)#define LED1_OFF (1<<5)#define LED2_OFF (1<<6)#define LED3_OFF (1<<7)#define LED4_OFF (1<<8)#define BEEP 0#define LED1 10#define LED2 12#define LED3 14#define LED4 16#define KEY1 0#define KEY2 6#define KEY3 10#define KEY4 12#define KEY5 14#define KEY6 22//--------------------Function Prototype------------------------------//static void LEDKEY_port_init(void);static void Show_num(int num);static void Beep_run(void);static void delay(unsigned int times);static void __irq key_handler(void);/* * *程序入口 */   void Main(void) { LEDKEY_port_init(); while(1) {  } } /*  *===================Function======================  *Name:Port_init  * Discription:init the GPIO  *=================================================  */  static void LEDKEY_port_init(void) { //初始化LED与BEEP所要用到的IO   用到的这五个端口都配置为输出 rGPBCON &= ~((3<<BEEP)|(3<<LED1)|(3<<LED2)|(3<<LED3)|(3<<LED4)); rGPBCON |= (1<<BEEP)|(1<<LED1)|(1<<LED2)|(1<<LED3)|(1<<LED4);  //初始化KEY所用的IO     所有的KEY端口都初始化为中断方式 rGPGCON &= ~((3<<KEY1)|(3<<KEY2)|(3<<KEY3)|(3<<KEY4)|(3<<KEY5)|(3<<KEY6)); rGPGCON |= (2<<KEY1)|(2<<KEY2)|(2<<KEY3)|(2<<KEY4)|(2<<KEY5)|(2<<KEY6);  //中断初始化EINT8// rEXTINT1 &=~((0xf)|(0xf<<12)|(0xf<<20)|(0xf<<24)|(0xf<<28));//设置K1的低电平中断 rEXTINT1 &=~0xfff0f00f; rEXTINT2 &=~(0xf<<12); rEINTPEND |=(1<<8)|(1<<11)|(1<<13)|(1<<14)|(1<<15)|(1<<19);//清除K1的中断标志 rEINTMASK = ~((1<<8)|(1<<11)|(1<<13)|(1<<14)|(1<<15)|(1<<19));//打开EINT8的中断使能  pISR_EINT8_23 = (U32)key_handler; EnableIrq(BIT_EINT8_23);//外部中断8-23共用的中断位使能，与ClearPending对应 }  /*  *===================Function======================  *Name:Show_num  * Discription:init the GPIO of Key  *=================================================  */ static void Show_num(int data) { if(data & 0x08)   rGPBDAT = rGPBDAT&(LED4_ON);    else           rGPBDAT = rGPBDAT|(LED4_OFF);  if(data & 0x04)   rGPBDAT = rGPBDAT&(LED3_ON);    else           rGPBDAT = rGPBDAT|(LED3_OFF);  if(data & 0x02)   rGPBDAT = rGPBDAT&(LED2_ON);    else           rGPBDAT = rGPBDAT|(LED2_OFF);  if(data & 0x01)   rGPBDAT = rGPBDAT&(LED1_ON);    else           rGPBDAT = rGPBDAT|(LED1_OFF); }  /*  *===================Function======================  *Name:Beep_run  * Discription:produce the buzzer  *=================================================  */ static void Beep_run(void){    rGPBDAT |= (0x1<<0);    delay(50);    rGPBDAT &= (0x0<<0);    delay(50);}  /*  *===================Function======================  *Name:delay  * Discription:produce delay ,the time is times.  *=================================================  */static void delay(unsigned int times){unsigned int i;for(;times>0;times--){for(i=400;i>0;i--);}} /*  *===================Function======================  *Name:key_handler  * Discription:when the key is pressed,  * the IRQ service will be run.  *=================================================  */  static void __irq key_handler(void) { Beep_run(); if(rEINTPEND & (1<<8)) { rEINTPEND |=1<<8; Show_num(1); } else if(rEINTPEND & (1<<11)) { rEINTPEND |=1<<11; Show_num(2); }else if(rEINTPEND & (1<<13)) {  rEINTPEND |=1<<13; Show_num(3); }  else if(rEINTPEND & (1<<14)) { rEINTPEND |=1<<14; Show_num(4); } else if(rEINTPEND & (1<<15)) { rEINTPEND |=1<<15; Show_num(5); } else if(rEINTPEND & (1<<19)) { rEINTPEND |=1<<19; Show_num(6); } ClearPending(BIT_EINT8_23);//用来清除中断标志位；针对全局的中断 } 

实现的功能：当按下mini2440下键盘下的6个按键中的一个时，蜂鸣器发出声音，并且4个发光二极管将以2进制的形式显示出按键的值。其中要比较注意的是EINTPEND的清零是通过置“1”清零的。因为在一些情况下，置一可以1+1=10，可以达到比较高效的目的。

其中以上中断程序是比较有问题的，因为在中断服务程序中还有延时，这样对实时性十分不利，但是在此只是进行ARM裸机程序的简单学习就不深入讨论了，因为我也是才开始学习，只是对一些东西知道，现在也不知道更好的解决方法。