MSP430F149模拟IIC读写24C02程序

板子上设置了EEPROM存储器,型号为AT24C02。
板子的硬件连接为:SCL--->P2.4,SDA--->P2.5。
直接了当,贴上程序!

========================24cxx.h文件=========================

#ifndef _24CXX_H_
#define _24CXX_H_

#include <msp430x14x.h>

#define WRITE_ADDR  0xA0  //A0 A1 A2均接地
#define READ_ADDR   0xA1  //A0 A1 A2均接地

#define SDA_BIT   BIT5
#define SCL_BIT   BIT4
#define IIC_PORT_DIR P2DIR
#define IIC_PORT_DATA P2OUT
#define SDA_BIT_DATA  (P2IN & BIT5)

#define SDA_OUT  (IIC_PORT_DIR |= SDA_BIT)
#define SDA_IN    (IIC_PORT_DIR &= ~SDA_BIT)
#define SDA_1     (IIC_PORT_DATA |= SDA_BIT)
#define SDA_0     (IIC_PORT_DATA &= ~SDA_BIT)

#define SCL_IN    (IIC_PORT_DIR &= ~SCL_BIT)
#define SCL_OUT  (IIC_PORT_DIR |= SCL_BIT)
#define SCL_1     (IIC_PORT_DATA |= SCL_BIT)
#define SCL_0     (IIC_PORT_DATA &= ~SCL_BIT)

void init_iic(void);
void iic_start(void);
void iic_stop(void);
void iic_ack(void);
void iic_no_ack(void);
unsigned char iic_test_ack(void);
void iic_write(unsigned char data);
unsigned char iic_read(void);

unsigned char iic_write_data(unsigned char StartAddress,unsigned char *date,unsigned char bytes);
unsigned char iic_read_data(unsigned char StartAddress,unsigned char *date,unsigned char bytes);

#endif
========================24cxx.c文件=========================

#include "24cxx.h"
#include "main.h"    //实际上需要包含延时#define CPU_F ((double)8000000)
                    //#define delay_us(x) __delay_cycles((long)(CPU_F*(double)x/1000000.0))
                    //#define delay_ms(x) __delay_cycles((long)(CPU_F*(double)x/1000.0))

/*
*IIC端口初始化
*/
void init_iic(void)
{
    SCL_OUT;    //SCL管脚为输出
    SDA_IN;        //SDA管脚为输入
    SCL_0;
    iic_stop();
}

/*
*IIC起始状态
*/
void iic_start(void)
{
    SDA_OUT;
    SDA_1;
    delay_us();
    SCL_1;
    delay_us();
    SDA_0;
    delay_us();
    SCL_0;
    delay_us();
}

/*
*IIC停止状态
*/
void iic_stop(void)
{
    SDA_OUT;
    SCL_0;
    delay_us();
    SDA_0;
    delay_us();
    SCL_1;
    delay_us();
    SDA_1;
    delay_us();
}

/*
*IIC应答
*/
void iic_ack(void)
{
    SDA_OUT;
    SDA_0;
    delay_us();
    SCL_1;
    delay_us();
    SCL_0;
    delay_us();
    SDA_1;
}

/*
*IIC无应答
*/
void iic_no_ack(void)
{
    SDA_OUT;
    SDA_1;
    delay_us();
    SCL_1;
    delay_us();
    SCL_0;
    delay_us();
}

/*
*IIC检测回应
*/
unsigned char iic_test_ack(void )
{
    unsigned char tmp;
    SDA_IN;                //设为输入
    delay_us();
    SCL_1;
    delay_us();
    tmp = SDA_BIT_DATA>>;
    delay_us();
    SCL_0;
    delay_us();
    return(tmp);
}

/*
*IIC写字节
*/
void iic_write(unsigned char data)
{
    SDA_OUT;
    unsigned char i,temp;
    ; i<; i++)
    {
        SDA_OUT;
        temp = data&0x80;
        if(temp == 0x80)
            SDA_1;            //判断发送位,送数据到数据线上
        else
            SDA_0;
        delay_us();
        SCL_1;                //置时钟信号为高电平,使数据有效
        delay_us();
        SCL_0;
        delay_us();
        data=data<<;
    }
    SDA_IN;
    delay_us();
}

/*
*IIC读字节
*/
unsigned char iic_read(void)
{
    unsigned char i,tmp;
    unsigned ;
    SDA_IN;                    //置数为输入
    ; i<; i++)
    {
        SCL_1;
        delay_us();
        ;
        SDA_IN;
        tmp = SDA_BIT_DATA;
        if(tmp == SDA_BIT)
            byte = (byte|0x01);
        delay_us();
        SCL_0;
        delay_us();
    }
    return(byte);
}

/*
*IIC写数据
*输入:start_addr起始地址
*  n_bytes写入字节数
*  dest_date写入的数据源
*输出:无
*/
unsigned char iic_write_data(unsigned char start_addr, unsigned char *dest_date, unsigned char n_bytes)
{
    unsigned ;
    iic_start();                //启动IIC
    iic_write(WRITE_ADDR);        //写24C02地址以
    )        //检测应答
     ;
    iic_write(start_addr);        //写对24C02操作的地址
    )
     ;
    ; i<n_bytes; i++)
    {
        iic_write(*dest_date);    //向24C02中写数据
        )
        ;
        dest_date++;
        start_addr++;
    }
    iic_stop();
    ;
}

/*
*IIC读数据
*输入:start_addr起始地址
*  n_bytes读出字节数
*输出:dest_date读出并保存的数据目的
*/
unsigned char iic_read_data(unsigned char start_addr, unsigned char *dest_date, unsigned char n_bytes)
{
    unsigned char i;
    iic_start();
    iic_write(WRITE_ADDR);
    )
        ;
    iic_write(start_addr);
    )
        ;
    iic_start();
    iic_write(READ_ADDR);
    )
        ;
    ; i<n_bytes; i++)
    {
        *dest_date = iic_read();
        iic_ack();
        dest_date++;
    }
    *dest_date = iic_read();
    iic_no_ack();
    iic_stop();
    ;
}

测试结果采用串口输出方式,main包含下面的步骤。

unsigned ] = {],ret = ;

init_iic();
printf("24c02 iic init ok\r\n");
printf(],iic_buf[],iic_buf[],iic_buf[]);
ret = iic_write_data(,iic_buf,);
printf( ? "err" : "ok");
ret = iic_read_data(,iic_rdbuf,);
printf( ? "err" : "ok");
printf(],iic_rdbuf[],iic_rdbuf[],iic_rdbuf[]);

实际测试显示:

MSP430F149模拟IIC读写24C02程序

/*
页写函数,写入起始地址,数据,字节数
*/
unsigned char EepromPageWrite(EEPROM_ADDR_TYPE address, unsigned char *pdata, unsigned char num)
{
    unsigned ;    //计算起始页
    unsigned ;        //计算结束页-1
    unsigned ;        //页写总循环数

    unsigned char pagebyte;            //页剩余字节数寄存器

    unsigned ;

    pagestart = EEPROM_PAGE_CAL(address);    //at24c01,02
    pageend = EEPROM_PAGE_CAL(address+num-);

    //页写
    ; pageloop <= (pageend-pagestart); pageloop++)
    {
        //计算本次写入的字节数
        pagebyte = (address|(EEPROM_PAGE_SIZE-)) - address + ;
        if (num <= pagebyte)
            pagebyte = num;

        num -= pagebyte; //剩余字节数

        I2cSendStart();
         == I2cSendByte(EEPROM_WRITE))
            );

    ...
}
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