i2c.c

这是机场入口电子卡检查登记的设备。有输入

#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>
#include	<ctype.h>
#include	<absacc.h>
#include	<float.h>
#include 	<INTRINS.h>
#include"my.h"
#define uchar unsigned char 
#define uint  unsigned int 
#define OK   0 //0 - respond
#define NOK  1 //1 - no respond

sbit	SDA				=P0^0;//  sda p00
sbit	SCL				=P0^1;//  scl p01
sbit	WP				=P0^2;//  /wc p02

#define		SCL_HIGH;	SCL=1;\
						_nop_();\
						_nop_();				
#define		SCL_LOW;	SCL=0;\
						_nop_();\
						_nop_();
#define		SDA_HIGH;	SDA=1;\
						_nop_();\
						_nop_();
#define		SDA_LOW;	SDA=0;\
						_nop_();\
						_nop_();

      /**************************************************
      串口0队列    pc
//使用w77e58 片内1k SRAM, 要定义为xdata , 
//为确保使用的是片内1k RAM, 最好和 _at_ 0x0000;联合使用
      **************************************************/

extern unsigned char xdata xBuf_0[130];
extern unsigned char xdata *Seri0_ReadSendPoint;
extern unsigned char xdata *Seri0_WriteSendPoint;
extern unsigned char data Seri0_SendNum; 
extern unsigned char xdata *Seri0_ReadReciPoint;
extern unsigned char xdata *Seri0_WriteReciPoint;
extern unsigned char data Seri0_ReciNum; 

_Delay(unsigned char a){
unsigned int bb;
for(;a>0;a--){
  bb=275;
  for(;bb>0;bb--);
  }
}

/**********************************************************
Function    : I2CStart
Description : I2C bus start signal
Input       : none
Output      : none
***********************************************************/
void 	I2CStart(void)
{   
	SDA_HIGH;
	SCL_HIGH;
	SDA_LOW;
	SCL_LOW;
}

/**********************************************************
Function    : I2CStop
Description : I2C bus stop signal
Input       : none
Output      : none
***********************************************************/
void 	I2CStop(void)
{     
	SDA_LOW;
	SCL_HIGH;
	SDA_HIGH; 
	SCL_LOW;             
}
/**********************************************************
Function    : WaitAck for check ack
Description : wait I2C slave to respond ack
Input       : none
Output      : 0 - respond; 1 - no respond
***********************************************************/
unsigned char 	WaitAck(void)
{
	unsigned char	bAck;
	
	SDA_HIGH;
	SCL_HIGH;
	if(SDA==0)
		bAck=OK;
	else
		bAck=NOK;
	SCL_LOW;
	return	bAck;
}
/**********************************************************
Function    : SendAck
Description : send ack to I2C slave 
Input       : none
Output      : none
***********************************************************/
void 	SendAck(void)
{
	SDA_LOW;
	SCL_HIGH;
	SCL_LOW;
	SDA_HIGH;	
}
/**********************************************************
Function    : SendNak
Description : send not ack signal to I2C slave
Input       : none
Output      : none
***********************************************************/
void 	SendNak(void)
{
	SDA_HIGH;
	SCL_HIGH;
	SCL_LOW;
	SDA_LOW;	
}

/**********************************************************
Function    : I2CSendByte
Description : send a byte to I2C slave
Input       : data - the byte to be sent
Output      : none
***********************************************************/
void 	I2CSendByte(unsigned char bChar)
{
	unsigned char	i;
	for(i=0;i<8;i++)
	{
      bChar<<=1;
      if(CY){SDA_HIGH}
      else  {SDA_LOW}
	  SCL_HIGH;
	  SCL_LOW;
	}
}

/**********************************************************
Function    : I2CReceiveByte
Description : Receive a byte from I2C slave
Input       : none
Output      : the byte received
***********************************************************/

unsigned char 	I2CReceiveByte(void)
{
	unsigned char	i,bChar;
	
	bChar=0;
	SDA=1;						//input init
	for(i=0;i<8;i++)
	{
		
		SCL_HIGH;
        bChar<<=1;
		if(SDA)	bChar++;		
		SCL_LOW;
	}
	return	bChar;
}
/**/
/*                  
功能：I2C芯片初始化
输入：none
输出: none
注意：
*/        
void	vInitI2C(void)
{
	WP=0;
	SCL_LOW;							
	SDA_LOW;
}			

/************************************************* 		                 
功能：	读I2C
输入：	
		Sla:		芯片地址(A0:EEPROM1;A4:EEPROM2)
		Address:	片内首地址
		Send_Data:	数据地址
		len:      	长度(<=128)
输出: 	0:正确; 1: 错误
注意： 
unsigned char 	IRcvStr( unsigned char  Sla,unsigned int  Address ,
                         unsigned char  *RcvData ,unsigned char  len) 
**************************************************/        
unsigned char 	IRcvStr( unsigned char  Sla,unsigned int  Address ,
                         unsigned char  *RcvData ,unsigned char  len)
{
	unsigned char	i;

	I2CStart();								
	I2CSendByte(Sla);						//SEND DEVICE ADDRESS
	if(WaitAck())
		goto I2CReadError;
//            return	(1);
	I2CSendByte( (uchar)(Address>>8) );		//SEND ADDRESS HIGH
	if(WaitAck())
		goto	I2CReadError;
//            return	(2);
	I2CSendByte( (uchar)Address );			//SEND ADDRESS LOW
	if(WaitAck())
		goto	I2CReadError;
//            return	(3);

	I2CStart();										
	Sla|=0x05;								//read bit=1   Sla|=0x01		
	I2CSendByte(Sla);						//SEND DEVICE ADDRESS	
	if(WaitAck())
		goto	I2CReadError;
//	    	return	(4);	
	for(i=0;i<len;i++)
	{
		RcvData[i]=I2CReceiveByte();		//SEND DATA
		if(i==len-1)
			SendNak();						//发送完最后字节，发送NAK
		else
			SendAck();
	}
	I2CStop();	
	return	OK;
I2CReadError:
	I2CStop();	
	return	NOK;
}

/******************************************************** 		                 
功能：	页写I2C
输入：	
		Sla:		芯片地址(A0:EEPROM1;A4:EEPROM2)
		Address:	片内首地址
		Send_Data:	数据源地址
		len:      	数据长度(<=128)
输出: 	0:正确; 1: 时序错误; 2:写入的数据读出后不对
注意：  不能跨页
*********************************************************/        
unsigned char 	ISendStr( unsigned char  Sla,unsigned int  Address ,
                          unsigned char  *Send_Data ,unsigned char  len )
{
	unsigned char	i;
	WP=0;
	I2CStart();								
	I2CSendByte(Sla);						//SEND DEVICE ADDRESS
	if(WaitAck())
		goto	ErrorI2CWrite;
	I2CSendByte( (uchar)(Address>>8) );		//SEND ADDRESS HIGH
	if(WaitAck())
		goto	ErrorI2CWrite;	
	I2CSendByte( (uchar)Address );			//SEND ADDRESS LOW
	if(WaitAck())
		goto	ErrorI2CWrite;	
	for(i=0;i<len;i++)
	{
		I2CSendByte(Send_Data[i]);			//SEND DATA
		if(WaitAck())
			goto	ErrorI2CWrite;
	}
	I2CStop();

	for(;;)									//查询是否写完
	{	
		I2CStart();								
		I2CSendByte(Sla);					
		if(!WaitAck())
			break;
	}
	WP=0;
    _Delay(10);	
/*         
	for(i=0;i<len;i++)
	{
		IRcvStr(Sla, Address ,&bI2CReadData ,1);		//写后读
		Address++;
		if( bI2CReadData!=Send_Data[i] ) 
			goto	ErrorI2CWrite;
	}
*/	
	_Delay(100);	
	return OK;//	return	0;

ErrorI2CWrite:
	I2CStop();
	WP=0;
	_Delay(100);		
	return	NOK;//	return	1;
}	

extern union d{         
  INT16U   u16;
  INT8U    u8[2];
}m2;
#define pageaddr  m2.u16 
#define pageaddrH m2.u8[0] 
#define pageaddrL m2.u8[1] 

extern unsigned char tmp;
unsigned char Sla;

/* 
       (my页)=0页~2047页(0页~0x7FF页)
AT24c512     Device Select Code 
-------------------------------------------------------------------------------------
                  |  Device Type Identifier        |    Chip Enable Address  | R/W  |
                  |  b7      b6      b5      b4    |        b3    b2     b1  |  b0  |
-------------------------------------------------------------------------------------
Device Select Code| 1          0        1        0 |        0    E2   E1     | R/W  |
-------------------------------------------------------------------------------------
Note: 1. The most significant bit, b7, is sent first. 

*/
Set_Sla(){
Sla=(pageaddrH & 0x6);
//if((Sla=0)||(Sla=2))Sla=4;
Sla|=0xA0; 
pageaddr<<=7;  
}

Pc2eep2pc()
{
 pageaddrH=xBuf_0[0];//页号
 pageaddrL=xBuf_0[1];
 Set_Sla();     
 tmp=ISendStr( Sla, pageaddr, xBuf_0+2, 128);//写入
 //xBuf_0[0]=tmp;
 //读eep操作：
 //if(tmp!=0){显示"Pc2eep2pc"}
 for(tmp=2;tmp<130;tmp++)xBuf_0[tmp]=0;
 //Set_Sla(); 
 tmp=IRcvStr(Sla, pageaddr ,xBuf_0+2 ,128);	//读出
 //xBuf_0[1]=tmp;
}