基于51单片机的电子钟.doc

#include reg52.h #define uchar unsigned char sbit addr0 = P1^4;//系统片选地址线0 sbit addr1 = P1^5;//系统片选地址线1 sbit addr2 = P1^6;//系统片选地址线2 sbit addr3 = P1^7;//系统片选地址线3 //行扫描数组 uchar code scan[8] = {0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};//row0--row7 //数码管显示的段码表 uchar code table[18] ={0xc0,0xf9,0xa4,0xb0,0x99,0x92,//0,1,2,3,4,5 0x82,0xf8,0x80,0x90,0x88,0x83,//6,7,8,9,a,b 0xc6,0xa1,0x86,0x8e,0xbf,0xff};//c,d,e,f,-,空格 uchar dispbuf[8]; //显示缓冲区 unsigned char second,minute,hour,count,flag,keybit;//秒,分,时,50ms计数器,数码管刷新标志 /******************************延时函数****************************/ void delay(unsigned int loop) { unsigned int i ; //loop 为执行空指令的次数,改变它可一改变延时时长 for(i=0;iloop;i++);//循环执行空指令loop次,达到延时目的 } /***********************************初始化函数*************************/ void initial() { uchar j; second=0x00;//秒清零 minute=0x00;//分清零 hour = 12; //时12 count = 20;//50毫秒置初值 keybit = 0;//读键延时标志 flag = 0x01;//清除刷新标志 for(j=0;j8;j++) dispbuf[j] = 1;//清数码管显示缓冲区 TMOD = 0x11;//T0 T1工作于方式1 TL1 = 0x00; TH1 = 0x4C;//50ms定时初值 ET1 = 1;//允许T1中断 PT1 = 1;//T1中断优先级高 EA = 1;//开中断 TR1 = 1;//T1开始计时 } /******************************显示+读键*************************/ void ledscan() { unsigned char i,key,value,keyvalue,dispvalue; for(i=0;i8;i++){ addr3 = 0; addr0 = 0; addr1 = 1; addr2 = 0;//开发板上U4（74HC574）的片选地址 P0 = 0xff; //关显示 addr3 = 1; addr3 = 0;//在U4的11脚（锁存信号）产生上升沿 P2 = scan[i];//取row0--row7行扫描数据 addr0 = 0; addr1 = 0; addr2 = 1;//开发板上U6（74HC244）的片选地址 addr3 = 1; P0 = 0xff;//准备读取按键 if((P0 !=0xff) keybit==0)//是否有按键和按键标志是否被清除 {value = 0; key = ~P0; keybit = 1;//置已按键标志 while(key){ value++; key = key /2; } keyvalue = 8*i + value;//计算十六进制键值 switch(keyvalue)//转按键功能处理 { case 4: