at24c02.c

来自「在STC51上开发的一个电子称程序 KEILUV3环境开发」· C语言 代码 · 共 134 行

#include "hardware.h"

/***************************************************************************/
#define	WriteDeviceAddress 0xa0
#define	ReadDviceAddress 0xa1

/***************************************************************************/
void delaysmMs(unsigned int number)
{
	unsigned char temp;
	for(;number!=0;number--) 
	{
	 for(temp=112;temp!=0;temp--); 
	}
}

/***************************************************************************/
void Start() 
{
	I2CSDA=1;
	I2CSCL=1;
	I2CSDA=0;
	I2CSCL=0;
}

/***************************************************************************/
void Stop()
 {
	I2CSCL=0;
	I2CSDA=0;
	I2CSCL=1;
	I2CSDA=1;
}

/***************************************************************************/
void Ack() 
{
	I2CSDA=0;
	I2CSCL=1;
	I2CSCL=0;
	I2CSDA=1;
}

/***************************************************************************/
void NoAck()
 {
	I2CSDA=1;
	I2CSCL=1;
	I2CSCL=0;
}

/***************************************************************************/
bit TestAck()
 {
	bit ErrorBit;
	I2CSDA=1;
	I2CSCL=1;
	ErrorBit=I2CSDA;
	I2CSCL=0;
	return(ErrorBit);
}

/***************************************************************************/
void Write8Bit(unsigned char input) 
{
	unsigned char temp;
	for(temp=8;temp!=0;temp--) 
    {
		I2CSDA=(bit)(input&0x80);
		I2CSCL=1;
		I2CSCL=0;
		input=input<<1;
	}
}


/**************************写入数据的指针，地址，写入数据的数量****************************************/
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();
	delaysmMs(10);
}

/***************************************************************************/
unsigned char Read8Bit() 
{
	unsigned char temp,rbyte=0;
	for(temp=8;temp!=0;temp--) 
    {
		I2CSCL=1;
		rbyte=rbyte<<1;
		rbyte=rbyte|((unsigned char)(I2CSDA));
		I2CSCL=0;
	}
	return(rbyte);
}

/**************************读出数据的指针，地址，读出数据的数量********************************/
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();
}