EEPROM 93c46 with 89c51

void chngestate(unsigned char command)
{unsigned char i;


cs=0;//chip select
Din=0;//In
CLK=0;//Clock
CLK=0;
cs=1;
Din=1;
CLK=1;
CLK=0;
for (i=0;i<7;i++)
{
if (command&0x80)
Din=1;
else
Din=0;
CLK=1;
command<<=1;
CLK=0;
}
buf<<=1;
if (command&0x80)
Din=1;
else
Din=0;
CLK=1;
cs=0;
_nop_();
_nop_();
}
int eeread(unsigned char address)
{
unsigned int result=0;
unsigned int c=0x8000;
unsigned char i,buf;
buf=address&(0xbf)|(0x80);
cs=0;
Din=0;
CLK=0;
CLK=0;
cs=1;
Din=1;
CLK=1;
CLK=0;
for (i=0;i<8;i++)
{
if (buf&0x80)
Din=1;
else
Din=0;
CLK=1;
buf<<=1;
CLK=0;
}
Din=0;
//16 bit read msb first
for (i=0;i<16;i++)
{
CLK=1;
if (Dout) result|=c;//out
CLK=0;
c>>=1;
}
CLK=1;
cs=0;
Din=0;
return(result);
}
void eewrite(unsigned int dat,unsigned char address)
{ unsigned int buf1=dat;
unsigned char i,buf;
buf=address&(0x7f)|(0x40);
cs=0;
Din=0;
CLK=0;
cs=1;
CLK=0;
Din=1;
CLK=1;
CLK=0;
for (i=0;i<8;i++)
{
if (buf&0x80)
Din=1;
else
Din=0;
CLK=1;
buf<<=1;
CLK=0;
}
//send 16 bit data msb first
for (i=0;i<15;i++)
{
if (buf1&0x8000)
Din=1;
else
Din=0;
CLK=1;
buf1<<=1;
CLK=0;
}
if (buf1&0x8000)
Din=1;
else
Din=0;
CLK=1;
Din=0;
cs=0;
_nop_();
_nop_();
cs=1;
_nop_();
_nop_();
while (Dout!=1);
cs=0;
_nop_();
_nop_();
}

Thanks for the reply.
What about 8 bit mode?

Hi Mansoor,
If you don't care about the overhead, I think you can use the following method to implement your own 8-bit read/write.

#define S_CONST_EEPROM_START_ADDR	0x01	// 0x01 ~ 0x3f
#define GET_HIGH(xx)		( (BYTE) ((xx) >> 8) )
#define GET_LOW(xx)			( (BYTE) ((xx) & 0x00ff) )

//////////////////////////////////////////////////////////////////////////////
// Function name  : EepromWriteOneByte
// Description 	  : Eeprom Write One Byte through Driver
// Return Value   :
// [#05]
BYTE EepromWriteOneByte(BYTE pos, BYTE byteValue)
{
	BYTE cAdr, cResult;
	WORD sData, sDataOut;

	// write out a word
	cAdr = S_CONST_EEPROM_START_ADDR + pos / 2;
	vWriteDisable();
	sDataOut = sReadWord(cAdr);  // Address from 0x00 to 0x3F
	if (pos % 2)
		sData = (GET_HIGH(sDataOut)<<8) | byteValue;	// odd
	else
		sData = GET_LOW(sDataOut) | (byteValue << 8);	// even

	vWriteEn();
	cWriteWord(cAdr, sData);
	vWriteDisable();
	cResult = EepromReadOneByte(pos);


	return cResult;
}

//////////////////////////////////////////////////////////////////////////////
// Function name  : EepromReadOneByte
// Description 	  : Eeprom Read One Byte through Driver
// Return Value   :
// [#05]
BYTE EepromReadOneByte(BYTE pos)
{
	BYTE cAdr, cResult;
	WORD sDataOut;


	// read back check
	cAdr = S_CONST_EEPROM_START_ADDR + pos / 2;
	vWriteDisable();
	sDataOut = sReadWord(cAdr);  // Address from 0x00 to 0x3F
	if (pos % 2)
		cResult = GET_LOW(sDataOut); // odd
	else
		cResult = GET_HIGH(sDataOut); // even


	return cResult;
}

What do you mean by overheads. Thanks for your efforts in answering my query.

Mansoor

I have just completed the project. Thanks for all who helped. I have tried to develop generalize routines for reading/writing in 8 bits.
Any body interested,Pl. contact me on mansoork38@hotmail.com.

Mansoor