#define IIC_READ 0XA1    //定義讀指令
#define IIC_WRITE 0XA0   //定義寫指令
#define NOP _nop_()
#define uchar unsigned char
#define uint  unsigned int
#include "reg52.h"
#define IIC_READ 0XA1    //定義讀指令
#define IIC_WRITE 0XA0   //定義寫指令
#define NOP _nop_()
uchar readbyteseq(uint add,uchar *ptr,uint readlen);
uchar writebyteseq(uint add,uchar *ptr,uint writelen);
void delay10ms(void);
//#define SDA INT0
//#define SCL T0
//==============================
uchar xdata buff[2000]; //save the byte read out  form iic device in test operation
uchar xdata readbuff[232];//測試數組，暫存寫入讀出數據
//uchar writebuff[32];
//===============================
sbit SDA=P3^5;//P2^7; //THE SDA BIT IS PORT 2 BIT 7
sbit SCL=P3^4;//P2^6; //THE SCL BIT IS PORT 2 BIT 6
sbit SEN=P3^3;//P2^6; //THE SCL BIT IS PORT 2 BIT 6
sbit STE=P3^2;//P2^6; //THE SCL BIT IS PORT 2 BIT 6
uchar bdata bbyte;//定義位操作用數組，采用此方法可提高位操作速度
sbit a0=bbyte^0;
sbit a1=bbyte^1;
sbit a2=bbyte^2;
sbit a3=bbyte^3;
sbit a4=bbyte^4;
sbit a5=bbyte^5;
sbit a6=bbyte^6;
sbit a7=bbyte^7;
//========================================
bit IFACK; //record the SDA state to confirn if ACK has happened 
bit NO_ACK; //no ack flag
bit BUS_FAULT; //bus fault flag
//========================================
void start(void)
{
 SCL=0;
 SDA=1;
 SCL=1;
 SDA=0;
 SCL=0;
}
//=======================================
//FUNCTION:ROUTES TO PROVIDE A STOP SIGNAL
void stop(void)
{
 SCL=0;
 SDA=0;
 SCL=1;
 SDA=1;
 SCL=0;
}
//=====================================
//FUNCTION:ROUTES TO PROVIDE ACK SINGAL
void ack(void)
{
 SCL=0;
 SDA=0;
 SCL=1;
 SCL=0;
}
//=====================================
//FUNCTION:ROUTES TO RELEASE THE SDA TO RECEIVE A ACK SIGNAL 
//              OR TO PROVIDE A NO_ACK SIGNAL
//type=1等待應答信號
//type=0 產生無應答信號
void nack(uchar type)
{
SCL=0;
SDA=1;
SCL=1;
IFACK=SDA;
SCL=0;
 if(type)
 {
  if(IFACK)//如果無應答信號，則置標志位NO_ACK,程序中止
  { 
   NO_ACK=1;//用戶可以加入自己的異常處理程序
   //while(1);
  }
  else NO_ACK=0;
 }
}
//=======================================================
//FUNCTION:THE IIC DEVICE SHIFT OUT A BYTE  TO THE MASTER
uchar  inbyte(void) {//從IIC器件中讀出數據
 SDA=1;
 SCL=1;
 a7=SDA;
 SCL=0;
 SCL=1;
 a6=SDA;
 SCL=0;
 SCL=1;
 a5=SDA;
 SCL=0;
 SCL=1;
 a4=SDA;
 SCL=0;
 SCL=1;
 a3=SDA;
 SCL=0;
 SCL=1;
 a2=SDA;
 SCL=0;
 SCL=1;
 a1=SDA;
 SCL=0;
 SCL=1;
 a0=SDA;
 SCL=0;
 return(bbyte);
}
//=======================================================
//FUNCTION:THE IIC DEVICE SHIFT IN A BYTE FROM THE MASTER 
void outbyte(uchar outdata) {//將數據寫放IIC器件
 bbyte=outdata;
 SDA=a7;
 SCL=1;
 SCL=0;
 SDA=a6;
 SCL=1;
 SCL=0;
 SDA=a5;
 SCL=1;
 SCL=0;
 SDA=a4;
 SCL=1;
 SCL=0;
 SDA=a3;
 SCL=1;
 SCL=0;
 SDA=a2;
 SCL=1;
 SCL=0;
 SDA=a1;
 SCL=1;
 SCL=0;
 SDA=a0;
 SCL=1;
 SCL=0;
}
/*
//======================================================
//FUNCTION:BYTE WRITE.  'add'     THE WRITE ADDRESS, 'wbyte'   THE DATA WANT TO WRITE
void writebyte(uint add,uchar wbyte)//add為寫入地址，wbyte為寫入數據
{
 uchar temph,templ;
 temph=(uchar)(add/256);
 templ=(uchar)(add%256);
 if(!STE)
 return;
 SEN=0;
 if(!STE)
 {
 SEN=1;
 SCL=1;
 SDA=1;
 return;
 }
 start();    //開始信號
 outbyte(IIC_WRITE|(temph<<1));   //寫命令
 nack(1);   //等待應答
 outbyte(templ);  //寫地址
 nack(1);
 outbyte(wbyte);   //寫數據
 nack(1);   //等待應答
 stop();    //停止信號
 SCL=1;
 SDA=1;
 SEN=1;
}
//=====================================================
//FUNCTION:RANDOM READ.'add' IS THE ADDRESS WANT TO READ
uchar readbyte (uint add)//add為讀地址
{
uchar temp,temph,templ; 
 temph=(uchar)(add/256);
 templ=(uchar)(add%256);
 if(!STE)
 return 0XFF;
 SEN=0;
 if(!STE)
 {
  SCL=1;
 SDA=1;
 SEN=1;
 return 0XFF;
 }
 start();   //開始信號
 outbyte(IIC_WRITE|(temph<<1));   //寫命令
 nack(1);   //等待應答
 outbyte(templ);  //寫地址
 nack(1);
 start();   //開始信號
 outbyte(IIC_READ|(temph<<1));   //讀命令
 nack(1);   //等待應答
 temp=inbyte();   //讀數據
 nack(0);   //無應答
 stop();    //停止信號
 SEN=1;
 SCL=1;
 SDA=1;
 return(temp);
}
*/
//=================================================
//連寫函數
//add為讀起始地址，ptr數據保存指針,writelen為寫入數據長度
uchar writebyteseq(uint add,uchar *ptr,uint writelen)
{
 //uchar temp;
 data uchar temph,templ;
data uint i;
 temph=(uchar)(add/256);
 templ=(uchar)(add%256);
  if(!STE)
 return 0XFF;
 SEN=0;
 if(!STE)
 {
  SCL=1;
 SDA=1;
 SEN=1;
 return 0XFF;
 }
 start();   
 outbyte(IIC_WRITE|(temph<<1));  
 nack(1);  
 outbyte(templ);
 nack(1);
 for(i=0;i<writelen;i++)
 {
  outbyte(*(ptr+i));    
  SCL=0;
SDA=1;
SCL=1;
SCL=0;
  //nack(1);
 }

 stop(); 
   SCL=1;
 SDA=1;
 SEN=1;
  return 0;
}
//=================================================
//連讀函數
//add為讀起始地址，ptr數據保存指針,writelen為讀出數據長度
uchar readbyteseq(uint add,uchar *ptr,uint readlen)
{

xdata uchar temph,templ;
 uint i;

 temph=(uchar)(add/256);
 templ=(uchar)(add%256);
   if(!STE)
   {
     SCL=1;
 SDA=1;
 SEN=1;
 return 0XFF;
 }
 SEN=0;
 if(!STE)
 {
  SCL=1;
 SDA=1;
 SEN=1;
 return 0XFF;
 }
 start();
 outbyte(IIC_WRITE|(temph<<1));
 nack(1);
 outbyte(templ);
 nack(1);
 start();
 outbyte(IIC_READ|(temph<<1));
 nack(1);
 for(i=0;i<readlen-1;i++)
 {
  *(ptr+i)=inbyte();
  ack();
  
 }
 *(ptr+readlen-1)=inbyte();
 nack(0);
 stop();
   SCL=1;
 SDA=1;
 SEN=1;
 return 0;
}
//=======================================================
//THIS IS A TEST OPERATION 

void delay10ms(void)
{
xdata int i;
for(i=0;i<1000;i++)
;
}
//=======================================================
//THIS IS A TEST OPERATION