CT107D蓝桥杯IIC驱动通用所有单片机（7）

#ifndef _IIC_H
#define _IIC_H

#include "regx52.h"
#include "intrins.h"

#define somenop {_nop_();_nop_();_nop_();_nop_();_nop_();}
#define SlaveAddrW 0xA0
#define SlaveAddrR 0xA1

//总线引脚定义
sbit SDA = P2^1;  /* 数据线 */
sbit SCL = P2^0;  /* 时钟线 */

//函数声明
void IIC_Start(void);
void IIC_Stop(void);
void IIC_Ack(unsigned char ackbit);
void IIC_SendByte(unsigned char byt);
bit IIC_WaitAck(void);
unsigned char IIC_RecByte(void);

#endif

/*
程序说明: IIC总线驱动程序
软件环境: Keil uVision 4.10
硬件环境: CT107单片机综合实训平台(12MHz)
日    期: 2011-8-9
*/

#include "iic.h"

//总线启动条件
void IIC_Start(void)
{
SDA = 1;
SCL = 1;
somenop;
SDA = 0;
somenop;
SCL = 0;
}

//总线停止条件
void IIC_Stop(void)
{
SDA = 0;
SCL = 1;
somenop;
SDA = 1;
}

//应答位控制
void IIC_Ack(unsigned char ackbit)
{
if(ackbit)
{
SDA = 0;
}
else
{
SDA = 1;
}
somenop;
SCL = 1;
somenop;
SCL = 0;
SDA = 1;
somenop;
}

//等待应答
bit IIC_WaitAck(void)
{
SDA = 1;
somenop;
SCL = 1;
somenop;
if(SDA)
{
SCL = 0;
IIC_Stop();
return 0;
}
else
{
SCL = 0;
return 1;
}
}

//通过I2C总线发送数据
void IIC_SendByte(unsigned char byt)
{
unsigned char i;
for(i=0;i<8;i++)
{
if(byt&0x80)
{
SDA = 1;
}
else
{
SDA = 0;
}
somenop;
SCL = 1;
byt <<= 1;
somenop;
SCL = 0;
}
}

//从I2C总线上接收数据
unsigned char IIC_RecByte(void)
{
unsigned char da;
unsigned char i;

for(i=0;i<8;i++)
{
SCL = 1;
somenop;
da <<= 1;
if(SDA)
da |= 0x01;
SCL = 0;
somenop;
}
return da;
}