at24c02+c51单片机

#include <reg51.h> #include <intrins.h> #define uchar unsigned char sbit scl=P1^5; sbit sda=P1^6; uchar sec=0,min=0,tt=0; uchar shum[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90}; //8位扫描显示，共阳数码管 void somenop() { uchar i=5; while(i--) { _nop_(); } } void delaym() { uchar i; for(i=0;i<0xff;i++); } void init() { sda=1; somenop(); scl=1; somenop(); } void star() { sda=1; somenop(); scl=1; somenop(); sda=0; somenop(); } void stop() { sda=0; somenop(); scl=1; somenop(); sda=1; somenop(); } void ack() { scl=1; somenop(); scl=0; somenop(); } void write_byte(uchar date) { uchar i,temp; temp=date; for(i=0;i<8;i++) { scl=0; somenop(); if((temp&0x80)==0x80) { sda=1;} else { sda=0;} temp=temp<<1; somenop(); scl=1; somenop(); scl=0; somenop(); } scl=0; somenop(); sda=1; somenop(); } uchar read_byte() { uchar i,temp1,j; scl=0; somenop(); sda=1; somenop(); for(i=0;i<8;i++) { scl=1; somenop(); j=sda; temp1=(temp1<<1)|j; scl=0; somenop(); } return temp1; } void write_address(uchar address,uchar date) { star(); write_byte(0xa0); ack(); write_byte(address); ack(); write_byte(date); ack(); stop(); } uchar read_address(uchar address) { uchar redata; star(); write_byte(0xa0); ack(); write_byte(address); ack(); star(); write_byte(0xa1); ack(); redata=read_byte(); stop(); return redata; } void timer0() interrupt 1 { TH0=(65536-50000)/256; TL0=(65536-50000)%256; tt++; if(tt==20) { tt=0; sec++; write_address(10,sec); delaym(); //把秒写入AT24C02的10地址 if(sec==60) { sec=0; min++; write_address(100,min); delaym(); //单片机写数据会占用一些时间，所以延时一会儿较好 if(min==60) { min=0; } } } } /* void int0(void) interrupt 0 { EA=0; min++; if(min==60) { min=0; } write_address(100,min); //把分写入AT24C02的100地址 delaym(); EA=1; } */ void disp() {P2=0X00; P0=shum[sec%10];//sec 个位 P2=0x01; delaym(); P2=0X00; P0=shum[sec/10];//sec 十位 P2=0x02; delaym(); P2=0X00; P0=shum[min%10]&0x7f; //加小数点 P2=0x04; delaym(); P2=0X00; P0=shum[min/10]; P2=0x08; delaym(); P2=0X00; } void main() { TMOD=0x01; TH0=(65536-50000)/256; TL0=(65536-50000)%256; ET0=1; TR0=1; init(); EA=1; sec=read_address(10);//从10地址读出秒数据 min=read_address(100);//从100地址读出分数据 while(1) { disp(); } }