原创 C8051F020读写24C16

说明

本程序是C8051F020，查询方式读写24C16的程序；阅读本文这前，最好熟悉一下C8051F020端口配置、SMBUS、IIC、及24C16的相关资料和文档。

电路

//代码
使用 Keil C V8.02

#include "C8051F020.h"

#define IICDEVSEL          0xA0

#define IICWRITE              0

#define IICREAD               1

sbit IIC_WP = P3^0;

/*

 * C8051F020的SMBUS初始化配置、端口配置

 */

void IIC_Init()

{

       //

       SMB0CR
= 0x40;

       return
;

}

/*

 * C8051F020的SMBUS总线使能控制

 */

void IIC_BusEnable(unsigned char enable)

{

if(enable)

{

    //SMBUS 总线使能

              SMB0CN
|= 0x40;

}

else

{

    //SMBUS 总线不使能

              SMB0CN
&= 0xBF;

}

}

/*

 * 向24C16写地址

 */

char IIC_WriteAddress(unsigned int addr)

{

       unsigned
char xdata temp;

       //产生START状态

       STA
= 1;

       while(1)

       {

              switch
(SMB0STA)

              {

                     case:
0xF8:

                               break;

                     case
0x08:

         
                  //取出地址的8~10位，合并到器件选择命令字节中

                            temp
= (unsigned char)(addr>>8);

                            temp
&= 0x07;

                            temp
<<= 1;

                            SMB0DAT
= IICDEVSEL | IICWRITE | temp;

                            STA
= 0;

                            SI
= 0;

                            break;

                     case
0x18:

                            //发送低8位地址

                            SMB0DAT
= (unsigned char)(addr);

                            STA
= 0;

                            SI
= 0;

                            break;

                     case
0x28:

                            //地址发送正确的完成

                            return
0;

                            break;

                     default:

                            //地址发送错误

                            STO
= 1;

                            SI
= 0;

for(i=0; i<3; i++); //delay for stop state transmitted

                            return
-1;

                            break;

              }

       }

}

/*

 * 向24C16写数据

 */

char IIC_Write(unsigned char len, unsigned
char* buffer)

{

       unsigned
char xdata i;//

       i
= 0;

       while(1)

       {

              switch
(SMB0STA)

              {

                     case:
0xF8:

                                break;

                     case
0x28:

                            if(i)>

                            {

                                   SMB0DAT
= *buffer;

                                   buffer++;

                                   i++;

                                   SI
= 0;

                            }

                            else

                            {

                                   STO
= 1;

                                   SI
= 0;

                                   for(i=0; i<3;
i++); //delay for stop state transmitted

                                return 0;

                            }

                            break;

                     default:

                            STO
= 1;

                            SI
= 0;

                            for(i=0;
i<3; i++); //delay for stop state transmitted

                            return
-1;

                            break;

                     }

              }

       return
0;

}

/*

 * 从24C16中读数据

 */

unsigned char IIC_Read(unsigned char len,
unsigned char* buffer)

{

       unsigned
char xdata i;

       i
= 0;

       //iic
repeat start

       STA
= 1;

       SI
= 0;

       while(1)

       {

              switch
(SMB0STA)

              {

                     case:
0xF8:

                             break;

                     case
0x10:

                            SMB0DAT
= IICDEVSEL | IICREAD;

                            STA
= 0;

                            SI
= 0;

                            break;

                     case
0x40:

                            i++;

                            if(i
== len)

                            {

                                   //如果是最后一个字节，则发送NOACK

                                   AA
= 0;

                            }

                            else

                            {

                                   //发送ACK

                                   AA
= 1;

                            }

                            SI
= 0;

                            break;

                     case
0x50:

                            *buffer
= SMB0DAT;

                            buffer++;

                            i++;

                            if(i
== len)

                            {

                                    //如果是最后一个字节，发送NOACK

                                   AA
= 0;

                            }

                            else

                            {

                                   //发关ACK

                                   AA
= 1;

                            }

                            SI
= 0;

                            break;

                     case
0x58:

                            *buffer
= SMB0DAT;

                            STO
= 1;

                            SI
= 0;

for(i=0; i<3; i++); //delay for stop state transmitted

                            return
0;

                            break;

                     default:

                            STO
= 1;

                            SI
= 0;

for(i=0; i<3; i++); //delay for stop state transmitted

                            return
-1;

                            break;

              }

       }

       return
0;

}

/*

 * 测试程序

 */

unsigned char sendbuf[]={1,2,3,4,5,6,7,8};

unsigned char revbuf[8];

void main(void)

{

IIC_Init();

IIC_BusEnable(1);

IIC_WriteAddress(0x100);

IIC_Write(8,sendbuf);

IIC_WriteAddress(0x100);

IIC_Read(8,revbuf);

while(1);

}