24.c

单片机的24C02读写程序,使用Keil c编译器测试正常。

#include <reg51.h>
#include <stdio.h>

#ifdef MONITOR51                         /* Debugging with Monitor-51 needs   */
char code reserve [3] _at_ 0x23;         /* space for serial interrupt if     */
#endif                                   /* Stop Exection with Serial Intr.   */
                                         /* is enabled                        */

// 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

/***************************************************************************/
sbit	SCL=P2^0;
sbit	SDA=P2^1;

/***************************************************************************/
void DelayMs(unsigned int number) {
	unsigned char temp;
	for(;number!=0;number--) {
		for(temp=112;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) {
	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 char count; 
unsigned char *ramaddress;

/*------------------------------------------------
Setup the serial port for 1200 baud at 16MHz.
------------------------------------------------*/

#ifndef MONITOR51
    SCON  = 0x50;               /* SCON: mode 1, 8-bit UART, enabler cvr      */
    TMOD |= 0x20;               /* TMOD: timer 1, mode 2, 8-bit reload        */
    TH1   = 253;                /* TH1:  reload value for 1200 baud @ 16MHz   */
    TR1   = 1;                  /* TR1:  timer 1 run                          */
    TI    = 1;                  /* TI:   set TI to send first char of UART    */
#endif


*ramaddress=65;
	for (count=0;count<255;count++){
		*ramaddress=255-count;
		Write24c02(ramaddress,count,1);
	}
	for (count=0;count<255;count++){
		Read24c02(ramaddress,count,1);
		printf("address:%d data%c\n",(unsigned int)count,*ramaddress);
	}

}