example.c

24c02的简单读写 显示1-9个数 调试时间已经通过 希望对学习FLASH的朋友有所帮助

#include <reg51.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 };
*/
uchar  code  display1[17]={0xc0,0xf9,0xa5,0xb0,0x99,
        0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0xa2,
		0x86,0x8e,0xff};
//24c02接口
sbit SDA = P1^4;
sbit SCL = P1^3;
//max6675接口
sbit SO=P1^0;
sbit CS=P1^1;
sbit SCK=P1^2;

void start();		 //启动程序
void stop();		 //停止程序
uchar shin();		 //
bit shout(uchar write_data);
void write_byte( uchar addr, uchar write_data);	//写一个字节
void fill_byte(uchar fill_size,uchar fill_data);
void delayms(uint ms);
uchar read_current();					        //延时
uchar read_random(uchar random_addr);			//读数据

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

/********************** 主程序************************************/
main(void)
{
   uchar i;
   SDA = 1;
   SCL = 1;
   fill_byte(17,0xff);          // 将前72字节填充0xff 既先消影

   for(i = 0 ; i < 17; i++)    //写入显示代码到AT24C02
    {
      write_byte(i,display1[i]); //写入要读出的数据
    }
   for(i =0 ;i <17 ; i++)
   {
      P0 = read_random(i);	   //从AT24C02移出数据送到P0口显示
      delayms(350);
   }
}

/*************************开始函数*********************************/
void start()
 //开始位
{
   SDA = 1;
   SCL = 1;
   delayNOP();
   SDA = 0;
   delayNOP();
   SCL = 0;
}

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

/*************************** 从AT24C02移出数据到MCU*******************************/
uchar shin()

{
   uchar i,read_data;
   for(i = 0; i < 8; i++)
   {
    SCL = 1;
    read_data <<= 1;
    read_data |= SDA;      //
    SCL = 0;
   }
    return(read_data);
}

/************************从MCU移出数据到AT24C02************************************/
bit shout(uchar write_data)

{
   uchar i;
   bit ack_bit;
   for(i = 0; i < 8; i++)   // 循环移入8个位
   {
     SDA = (bit)(write_data & 0x80); //先接收最高位
    _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
}

/***********************在指定地址addr处写入数据write_data**********************************/
void write_byte(uchar addr, uchar write_data)

{
   start();
   shout(0xa0);			//写入器件地址
   shout(addr);			    //写入数据地址
   shout(0xa1);	   //写入数据
   stop();
   delayms(10);          // 写入周期
}

/***********************填充数据fill_data到EEPROM内fill_size字节*****************************/
void fill_byte(uchar fill_size,uchar fill_data)

{
   uchar i;
   for(i = 0; i < fill_size; i++)
   {
     write_byte(i, fill_data);
   }
}

/***********************在当前地址读取***********************************/
uchar read_current()

{
   uchar read_data;
   start();
   shout(0xa1);      //读取器件地址
   read_data = shin();
   stop();
   return read_data;
}

/**********************************************************/
uchar read_random(uchar random_addr)
// 在指定地址读取
{
   start();
   shout(0xa0);	  //写入器件地址
   shout(random_addr);//数据写入2402
   return(read_current());
}

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