at24.c

自己做的单片机Proteus仿真实例

#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
bit  write=0;
sbit seg1=P2^0;
sbit seg2=P2^1;
sbit scl=P2^6;
sbit sda=P2^7;
uchar sec,temp,aa;
uchar code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
void delay()
{;;;}
void delayms(uint z)
{
      uint i,j;
	  for(i=z;i>0;i--)
	    for(j=110;j>0;j--);
}
void start()
{
      sda=1;
	  delay();
	  scl=1;
	  delay();
	  sda=0;
	  delay();
}
void stop()
{
      sda=0;
	  delay();
	  scl=1;
	  delay();
	  sda=1;
	  delay();
}
void respons()
{
      uchar x;
	  scl=1;
	  delay();
	  while((sda==1)&&(x<250))
	       x++;
      scl=0;
	  delay();
}
void init()
{	  seg1=1;
      seg2=1;
      sda=1;
	  delay();
	  scl=1;
	  delay();
}
void write_byte(uchar date)
{
      uchar i,j;
	  j=date;
	  for(i=0;i<8;i++)
	  {
	         j=j<<1;
			 scl=0;
			 delay();
			 sda=CY;
			 delay();
			 scl=1;
			 delay();
      }
	  scl=0;
	  delay();
	  sda=1;
	  delay();
}
uchar read_byte()
{
      uchar i,k;
	  scl=0;
	  delay();
	  sda=1;
	  delay();
	  for(i=0;i<8;i++)
	  {
	         scl=1;
			 delay();
			 k=(k<<1)|sda;
			 scl=0;
			 delay();
	  }
	  return  k;
}
void  write_add(uchar address,uchar date)
{
      start();
	  write_byte(0xa0);
	  respons();
	  write_byte(address);
	  respons();
	  write_byte(date);
	  respons();
	  stop();
}
uchar read_add(uchar address)
{
      uchar date;
	  start();
	  write_byte(0xa0);
	  respons();
	  write_byte(address);
	  respons();
	  start();
	  write_byte(0xa1);
	  respons();
	  date=read_byte();
	  stop();
	  return date;
}
void display(uchar shi,uchar ge)
{
      P0=0xff;
	  seg1=0;
	  P0=table[shi];
	  delayms(5);
	  seg1=1;
	  P0=0xff;
	  seg2=0;
	  P0=table[ge];
	  delayms(5);
	  seg2=1;
}
void main()
{
      init();
	  TMOD=0x01;
	  ET0=1;
	  EA=1;
	  TH0=(65536-50000)/256;
	  TL0=(65536-50000)%256;
	  TR0=1;
	  while(1)
	  {
	          display(sec/10,sec%10);
			  if (write==1)
			  {
			          write=0;
					  write_add(2,sec);
			  }
			  aa=read_add(2);
			   if(aa==100)
			        aa=0;
			  P1=aa;
	  }
}
void ser() interrupt 1
{
      
	  TH0=(65536-50000)/256;
	  TL0=(65536-50000)%256;
	  temp++;
	  if(temp==20)
	  {
	          temp=0;
			  sec++;
			  write=1;
			  if(sec==100)
			        sec=0;
	  }
}