24c64.c

很强的射频卡reader源代码

//------------------------------------------------------------------
//24c64
//晶振：22.1184m
//------------------------------------------------------------------
#include "stc89c516.h"
#include <intrins.h>
sbit SDA=P1^1;
sbit SCL=P1^0;

#define uchar unsigned char
#define uint unsigned int									   
#define byte unsigned char


void delay()
{
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
}

/*
void delayms (uint x)
{
 byte j;
 while(x--){
    for(j=0;j<125;j++){;}
      }
} */

void I2C_Start()                      //I2C START
{
 SDA=1;
 _nop_();
 _nop_();
  SCL=1;
  delay();
   SDA=0;
   delay();
  SCL=0;
  _nop_();
  _nop_();
}

void I2C_Stop()             //I2C STOP
{
SDA=0;
_nop_();
_nop_();
SCL=1;
delay();
SDA=1;
delay();
}

bit  I2C_ReceiveAck() 
{
bit ck=0;
SDA=1;                  //THE HOST RELEASE THE BUS
_nop_();
_nop_();
SCL=1;           
_nop_();
_nop_();
_nop_();
_nop_();
ck=SDA;
_nop_();
_nop_();
_nop_();
_nop_();
SCL=0;
_nop_();
return(ck);
}


void I2C_SendAck()

{
SDA=0;
_nop_();
_nop_();
SCL=1;
delay();          //remain
SCL=0;
_nop_();
_nop_();
}

void I2C_SendNoAck()

{
SDA=1;
_nop_();
_nop_();
SCL=1;
delay();   //remain
SCL=0;
_nop_();
_nop_();
}

void I2C_SendByte(byte SData)
{uchar i;
for(i=0;i<8;i++)
{  SDA=(bit)(SData&0x80);
   SData=SData<<1;
   SCL=1;
   delay();
   SCL=0;
}
}


byte I2C_ReceiveByte()
{uchar i;
 byte RData;
 RData=0;

for(i=0;i<8;i++)
{  SDA=1;
  _nop_();
  SCL=1;
  _nop_();
  _nop_();
  RData=RData<<1;
  RData=RData|SDA;
  _nop_();
  _nop_();
  SCL=0;
}
return(RData);
}



unsigned char  write_Flash(unsigned int byte_address,unsigned char *a,unsigned char len)

{
	uchar i;
 
		
		I2C_Start();
		I2C_SendByte(0xa0);    //send slave address(write device)
		I2C_ReceiveAck();

		I2C_SendByte(byte_address/256);    //send sub address
		I2C_ReceiveAck();

		I2C_SendByte(byte_address%256);    //send sub address
		I2C_ReceiveAck();


		for(i=0;i<len;i++)
		{ 	
		do
		{
  			I2C_SendByte(a[i]);
		}	
		while(I2C_ReceiveAck()==1); 
		

		}
		

		I2C_Stop();
		return 0;
}

unsigned char  read_Flash(unsigned int byte_address,unsigned char *a,unsigned char len)
{
	uchar i;
	I2C_Start();
	I2C_SendByte(0xa0);    //send slave address(write device)
	I2C_ReceiveAck();
	I2C_SendByte(byte_address/256);    //send sub address
	I2C_ReceiveAck();
	I2C_SendByte(byte_address%256);    //send sub address
	I2C_ReceiveAck();


	I2C_Start();                              //I2C Start Again!
	I2C_SendByte(0xa1);    //send slave address(read device)
	I2C_ReceiveAck();
	for(i=0;i<len-1;i++)
	{
   		a[i]=I2C_ReceiveByte();
   		I2C_SendAck();
	}
	a[i]=I2C_ReceiveByte();
	I2C_SendNoAck();
	I2C_Stop();
	return 0;
}

unsigned char read_byte_Flash(unsigned int byte_addr)
{
	uchar read_data[2];	
	read_Flash(byte_addr,read_data,1);
	return read_data[0];
}

/*
main()
{byte *pData;
 uint addr;
  byte a[16]={0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
  pData=a;
   do
   {
      I2C_SendToSubAddress(0xA0,addr,pData,16);
      addr+=16;
   delayms (1);
   }while(addr!=0x2000);
while(1);
} */