24c02读程序C语言详解,24C02读写练习详细(C语言新手细看).doc

24c02读程序C语言详解,24C02读写练习详细(C语言新手细看).doc

#include #defineOP_READ0xa1// 器件地址以及读取操作

#defineOP_WRITE 0xa0// 器件地址以及写入操作

#defineMAX_ADDR 0x7f// AT24C02最大地址

unsigned char code dis_code[] = {0x7e,0xbd,0xdb,0xe7,0xdb,0xbd,0x7e,0xff};

// 写入到AT24C01的数据串

sbit SDA = P3^4;

sbit SCL = P3^3;

void start();

void stop();

unsigned char shin();

bit shout(unsigned char write_data);

unsigned char read_random(unsigned char random_addr);

void write_byte( unsigned char addr, unsigned char write_data);

void fill_byte(unsigned char fill_data);

void delayms(unsigned char ms);

main(void)

{

unsigned char i;

SDA = 1;

SCL = 1;

fill_byte(0xff);// 全部填充0xff

for(i = 0 ; i < 8; i++)//写入显示代码到AT24Cxx

{

write_byte(i, dis_code[i]);

}

i = 0;

while(1)

{

P0 = read_random(i);// 循环读取24Cxx内容，并输出到P0口

i++;

i &= 0x07;// 循环读取范围为0x00～0x07

delayms(250);

}

}

void start()

// 开始位

{

SDA = 1;

SCL = 1;

_nop_();

_nop_();

SDA = 0;

_nop_();

_nop_();

_nop_();

_nop_();

SCL = 0;

}

void stop()

// 停止位

{

SDA = 0;

_nop_();

_nop_();

SCL = 1;

_nop_();

_nop_();

_nop_();

_nop_();

SDA = 1;

}

unsigned char shin()

// 从AT24Cxx移入数据到MCU

{

unsigned char i,read_data;

for(i = 0; i < 8; i++)

{

SCL = 1;

read_data <<= 1;

read_data |= (unsigned char)SDA;

SCL = 0;

}

return(read_data);

}

bit shout(unsigned char write_data)

// 从MCU移出数据到AT24Cxx

{

unsigned char 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;

_nop_();

_nop_();

SCL = 0;

write_data <<= 1;

}

SDA = 1;// 读取应答

_nop_();

_nop_();

SCL = 1;

_nop_();

_nop_();

_nop_();

_nop_();

ack_bit = SDA;

SCL = 0;

return ack_bit;// 返回AT24Cxx应答位

}

void write_byte(unsigned char addr, unsigned char 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(unsigned char fill_data)

// 填充数据fill_data到EEPROM内

{

unsigned char i;

for(i = 0; i < MAX_ADDR; i++)

{

write_byte(i, fill_data);

}

}

unsigned char read_current()

// 在当前地址读取

{

unsigned char read_data;

start();

shout(OP_READ);

read_data = shin();

stop();

return read_data;

}

unsigned char read_random(unsigned char random_addr)

// 在指定地址读取

{

start();

shout(OP_WRITE);

shout(random_addr);

return(read_current());

}

void delayms(unsigned char ms)

// 延时子程序

{

unsigned char i;

while(ms--)

{

for(i = 0; i < 120; i++);

}

}