我需要一段单片机模拟IIC的程序

好的，以下是一段单片机模拟IIC的程序：

#include <reg51.h>

#define SCL P2_0
#define SDA P2_1

void start()
{
    SDA = 1;
    SCL = 1;
    SDA = 0;
    SCL = 0;
}

void stop()
{
    SDA = 0;
    SCL = 1;
    SDA = 1;
}

void write_byte(unsigned char dat)
{
    unsigned char i;

    for (i = 0; i < 8; i++)
    {
        SDA = dat & 0x80;
        SCL = 1;
        SCL = 0;
        dat <<= 1;
    }

    SDA = 1;
    SCL = 1;
    SCL = 0;
}

unsigned char read_byte()
{
    unsigned char i, dat = 0;

    SDA = 1;

    for (i = 0; i < 8; i++)
    {
        SCL = 1;
        dat <<= 1;
        dat |= SDA;
        SCL = 0;
    }

    return dat;
}

unsigned char i2c_write(unsigned char device_addr, unsigned char reg_addr, unsigned char *reg_data, unsigned char cnt)
{
    unsigned char i;

    start();

    write_byte(device_addr << 1);

    if (read_byte() != 0x18)
    {
        stop();
        return 1;
    }

    write_byte(reg_addr);

    if (read_byte() != 0x28)
    {
        stop();
        return 1;
    }

    for (i = 0; i < cnt; i++)
    {
        write_byte(reg_data[i]);

        if (read_byte() != 0x28)
        {
            stop();
            return 1;
        }
    }

    stop();

    return 0;
}

unsigned char i2c_read(unsigned char device_addr, unsigned char reg_addr, unsigned char *reg_data, unsigned char cnt)
{
    unsigned char i;

    start();

    write_byte(device_addr << 1);

    if (read_byte() != 0x18)
    {
        stop();
        return 1;
    }

    write_byte(reg_addr);

    if (read_byte() != 0x28)
    {
        stop();
        return 1;
    }

    start();

    write_byte((device_addr << 1) | 1);

    if (read_byte() != 0x40)
    {
        stop();
        return 1;
    }

    for (i = 0; i < cnt; i++)
    {
        reg_data[i] = read_byte();

        if (i == cnt - 1)
            SDA = 1;
        else
            SDA = 0;

        SCL = 1;
        SCL = 0;
    }

    stop();

    return 0;
}

希望这能帮到你！