24c08.c

24c08的用法!希望能给大家提供帮助!

#include <reg52.h>
#include <intrins.h>

#define uchar unsigned char
#define uint unsigned int

#define OP_WRITE 0xa0          // 器件地址以及写入操作
#define OP_READ  0xa1           // 器件地址以及读取操作

/*uchar code display[72]={
        0xFE,0xFD,0xFB,0xF7,0xEF,0xDF,0xBF,0x7F,
        0xBF,0xDF,0xEF,0xF7,0xFB,0xFD,0xFE,0xFF,
        0xFE,0xFC,0xF8,0xF0,0xE0,0xC0,0x80,0x00,
        0x80,0xC0,0xE0,0xF0,0xF8,0xFC,0xFE,0xFF,
        0xFC,0xF9,0xF3,0xE7,0xCF,0x9F,0x3F,
        0x9F,0xCF,0xE7,0xF3,0xF9,0xFC,0xFF,
        0xE7,0xDB,0xBD,0x7E,0xBD,0xDB,0xE7,0xFF,
        0xE7,0xC3,0x81,0x00,0x81,0xC3,0xE7,0xFF,
        0xAA,0x55,0x18,0xFF,0xF0,0x0F,
        0x00,0xFF,0x00,0xFF };*/

sbit SDA = P3^4;
sbit SCL = P3^3;
uchar i=1,j=0xfe;

void start();
void stop();
uchar shin();
bit shout(uchar write_data);
void write_byte( uchar addr, uchar write_data);
void fill_byte(uchar fill_size,uchar fill_data);
void delayms(uint ms);
uchar read_current();
uchar read_random(uchar random_addr);

#define delayNOP(); {_nop_();_nop_();_nop_();_nop_();};

/**********************************************************/
void int0(void) interrupt 0
{
 write_byte(i,j);
 delayms(1);//必须加延时
 P0=read_random(i);
 i++;
 j=(j<<1)|0x01;
 if(j==0xff){i=0;j=0xfe;}
 }
main(void)
{
   //uchar i;
   SDA = 1;
   SCL = 1;
 /*  fill_byte(72,0xff);          // 将前72字节填充0xff

   for(i = 0 ; i < 72; i++)    //写入显示代码到AT24C02
    {
      write_byte(i,display[i]);
    }
   for(i =0 ;i <72 ; i++)      //从AT24C02移出数据送到P0口显示
   {
      P0 = read_random(i);
      delayms(350);
   } 
}
*/
  fill_byte(16,0xff);
  EA=1;
  EX0=1;
  IT0=1;
  //P0=0x01;
  while(1);
 }
/**********************************************************/
void start()
 //开始位
{
   SDA = 1;
   SCL = 1;
   delayNOP();
   SDA = 0;
   delayNOP();
   SCL = 0;
}

/**********************************************************/
void stop()
 // 停止位
{
   SDA = 0;
   delayNOP();
   SCL = 1;
   delayNOP();
   SDA = 1;
}

/**********************************************************/
uchar shin()
// 从AT24C02移出数据到MCU
{
   uchar i,read_data;
   for(i = 0; i < 8; i++)
   {
    SCL = 1;
    read_data <<= 1;
    read_data |= SDA;
    SCL = 0;
   }
    return(read_data);
}

/**********************************************************/
bit shout(uchar write_data) 
// 从MCU移出数据到AT24C02
{
   uchar i;
   bit ack_bit;
   for(i = 0; i < 8; i++)   // 循环移入8个位
   {
     SDA = (bit)(write_data & 0x80);
    _nop_();
    SCL = 1;
    delayNOP();
    SCL = 0;
    write_data <<= 1;
   }
   SDA = 1;                     // 读取应答
   delayNOP();
   SCL = 1;
   delayNOP();
   ack_bit = SDA;
   SCL = 0;
   return ack_bit;            // 返回AT24C02应答位
}

/**********************************************************/
void write_byte(uchar addr, uchar write_data)
// 在指定地址addr处写入数据write_data
{
   start();
   shout(OP_WRITE);
   shout(addr);
   shout(write_data);
   stop();
   delayms(10);          // 写入周期
}

/**********************************************************/
void fill_byte(uchar fill_size,uchar fill_data)
// 填充数据fill_data到EEPROM内fill_size字节
{
   uchar i;
   for(i = 0; i < fill_size; i++)
   {
     write_byte(i, fill_data);
   }
}

/**********************************************************/
uchar read_current()
// 在当前地址读取
{
   uchar read_data;
   start();
   shout(OP_READ);
   read_data = shin();
   stop();
   return read_data;
}

/**********************************************************/
uchar read_random(uchar random_addr)
// 在指定地址读取
{
   start();
   shout(OP_WRITE);
   shout(random_addr);
   return(read_current());
}

/**********************************************************/
void delayms(uint ms) 
// 延时子程序
{
   uchar k;
   while(ms--)
   {
      for(k = 0; k < 120; k++);
   }
}