51单片机IO口模拟驱动AT24c02

#include#includevoid somenop(){ uchar i=5; while(i--) {  _nop_(); }}//8位扫描显示，共阳数码管uchar shum[]={              0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};void delaym(){ uchar i; for(i=0;i<0xff;i++); }void init();void star();void stop();void ack();void write_byte(uchar date);uchar read_byte();sbit scl=P1^2;sbit sda=P1^3;uchar sec,min=30,tt;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++;  if(sec==60)         {sec=0;min++;                    if(min==60)          { min=0;}           write_address(100,min); delaym();         }        write_address(10,sec); delaym();  //把秒写入AT24C02的10地址                                         //单片机写数据会占用一些时间，所以延时一会儿较好         }}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(){ P0=shum[sec%10];//sec 个位 P2=0x08; delaym(); P0=shum[sec/10];//sec 十位 P2=0x04; delaym(); P0=shum[min%10]&0x7f;   //加小数点 P2=0x02; delaym(); P0=shum[min/10]; P2=0x01; delaym();}void main(){    TMOD=0x01; ET0=1;    EX0=1;    IT0=1;    EA=1; TH0=(65536-50000)/256; TL0=(65536-50000)%256;    TR0=1;     init();        sec=read_address(10);     ／／从ＡＴ２４Ｃ０２的１０地址读出秒数据        min=read_address(100);／／从ＡＴ２４Ｃ０２的１００地址读出分数据        while(1)        {          disp();        }}