24c02.c

单片机开发资料光盘-双龙-686M.zip

#include <AT89X52.H>
// 对24C02的读、写
// extern void DelayMs(unsigned int);
// extern void Read24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes);
// extern void Write24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes);

/***************************************************************************/
#define	WriteDeviceAddress 0xa0
#define	ReadDviceAddress 0xa1
//unsigned char WriteDeviceAddress=0xa0;
//unsigned char ReadDviceAddress=0xa1;
/***************************************************************************/
sbit	SCL=P1^1;
sbit	SDA=P1^0;
/***************************************************************************/
void DelayMs(unsigned int number) {
	unsigned char temp;
	for(;number!=0;number--)
       {
		for(temp=224;temp!=0;temp--) {
		}
	}
}

/***************************************************************************/
void Start() {
	SDA=1;
	SCL=1;
	SDA=0;
	SCL=0;
}

/***************************************************************************/
void Stop() {
	SCL=0;
	SDA=0;
	SCL=1;
	SDA=1;
}

/***************************************************************************/
void Ack() {
	SDA=0;
	SCL=1;
	SCL=0;
	SDA=1;
}

/***************************************************************************/
void NoAck() {
	SDA=1;
	SCL=1;
	SCL=0;
}

/***************************************************************************/
bit TestAck() {
	bit ErrorBit;
	SDA=1;
	SCL=1;
	ErrorBit=SDA;
	SCL=0;
	return(ErrorBit);
}

/***************************************************************************/
void Write8Bit(unsigned char input) {
	unsigned char temp;
	for(temp=8;temp!=0;temp--) {
		SDA=(bit)(input&0x80);
		SCL=1;
		SCL=0;
		input=input<<1;
	}
}

/***************************************************************************/
void Write24c02(unsigned char *Wdata,unsigned char RomAddress,unsigned char number) {
	Start();
	Write8Bit(WriteDeviceAddress);
	TestAck();
	Write8Bit(RomAddress);
	TestAck();
	for(;number!=0;number--) {
		Write8Bit(*Wdata);
		TestAck();
		Wdata++;
	}
	Stop();
	DelayMs(10);
}

/***************************************************************************/
unsigned char Read8Bit() {
	unsigned char temp,rbyte=0;
	for(temp=8;temp!=0;temp--) {
		SCL=1;
		rbyte=rbyte<<1;
		rbyte=rbyte|((unsigned char)(SDA));
		SCL=0;
	}
	return(rbyte);
}

/***************************************************************************/
void Read24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes) 
   {
	//unsigned char temp,rbyte;
	Start();
	Write8Bit(WriteDeviceAddress);
	TestAck();
	Write8Bit(RomAddress);
	TestAck();
	Start();
	Write8Bit(ReadDviceAddress);
	TestAck();
	while(bytes!=1) {
	*RamAddress=Read8Bit();
	Ack();
	RamAddress++;
	bytes--;
	}
	*RamAddress=Read8Bit();
	NoAck();
	Stop();
}

/***************************************************************************/
void main(void)
{
 unsigned int ee_data=0xAA55;
 unsigned char i=0;
 DelayMs(1000);
 Write24c02((unsigned char *)&ee_data,0x10,2);
 DelayMs(1000);
 Read24c02((unsigned char *)&ee_data,0x10,2);
 if(ee_data==0xaa55)
 	{
 	P0=(unsigned char)ee_data;
 	DelayMs(1000);
 	P0=(unsigned char)(ee_data>>8);
	DelayMs(1000);
    while(1)
	  {
	   P0=~(1<<i);
	   DelayMs(1000);
	   if(i<7) 
	      i++;
	   else
	      i=0;
	  }
	}
 else
    {
	 P0=0x3c;
  	 while(1)
 		 ;
	 }
}