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code for interfacing 24C16 I2C EEPROM with 8051

Hello,

I am unable to interface the 24C16 in my 8051 board.
Can anyone give me the code (in 'C')required for interfacing the 24C16 using any two port lines.

Thanks,

Mohit

Parents

0 Jonh Bob over 18 years ago

Hello!
I have write a program to write and read to/from AT24c04 serial ROM (89C52 interface with AT24C04). I am using Keil C to program.

But i can read any data which i have write to AT24c04.
I don't know exacterly why.

My purpose is very simple. I listent from USART and get data from PC key board. If the character which i get from pc is 'w' or 'W' then i do get data from PC and write to AT24c04 until i get the 0x0D. Now if i get the 'r' or 'R' character from PC i read data which i have just write to AT24c04 and send back to PC.
But i can't read any.

Here is my code

#include <REG52.h>

unsigned char data DEVICEADD;

sbit SDA = P1^0;
sbit SCL = P1^1;

int data c;
char data wrom;
char data rrom;

void outchar(char data chr)
{
while(!TI)
{
}
TI = 0;
SBUF = chr;
}

void outstr(char* str)
{
while(*str != 0)
{
outchar(*str++);
}
}
char i2c_start(void)
{
/*
if(!SDA || !SCL)
return 0; // i2c_start error: bus not free
*/
// Both bus lines are high,
SDA = 0; // so set data line low to generate a start condition.
SCL = 0;
/*
SDA = 1;
SCL = 1;
SDA = 0;
SCL = 0;
*/
return 1;
}

void i2c_stop(void)
{
/*
SDA = 0;
SCL = 1;
SDA = 1;
*/
unsigned char input_var;
SCL = 1;
SDA = 0;
SCL = 1;
SDA = 1;
input_var = SDA;
}

// return ack value: 0 for fale; 1 for success
char i2c_write(char data byte)
{
int data i;
for(i = 0; i < 8 ; i++)
{
SDA = ((byte & 0x80) ? 1 : 0);
SCL = 1; // Ensure that the data is stable during the high period.
byte <<= 1;
SCL = 0;
}
// Get ack
SDA = 1;
SCL = 1;
i = SDA;
//i = 500;
SCL = 0;
/*
while(i-- && SDA)
{
}
*/
return !i; // Get data at end of cycle.
}

char i2c_writebyte(int data address, char data byte)
{
if(!i2c_start())
{
outstr("i2c_start error: bus not free.\n");
return 0;
}
if(!i2c_write(DEVICEADD))
{
i2c_stop();
i2c_start();
if(!i2c_write(DEVICEADD)) // Interface failed to acknowledge device address
{
i2c_stop();
outstr("Interface failed to acknowledge device address.\n");
return 0;
}
}

if(!i2c_write(address >>8)) // Interface failed to acknowledge byteH address
{
i2c_stop();
outstr("Interface failed to acknowledge byteH address.\n");
return 0;
}
if(!i2c_write(address)) // Interface failed to acknowledge byteL address
{
i2c_stop();
outstr("Interface failed to acknowledge byteL address.\n");
return 0;
}
if(!i2c_write(byte)) // Interface failed to acknowledge data
{
i2c_stop();
outstr("Interface failed to acknowledge data.\n");
return 0;
}
i2c_stop();
return 1; // success
}

char i2c_read(char data ACK)
{
char index, byte;
index = SDA; // Put data pin into read mode
byte = 0x00;
for(index = 0; index < 8; index++) // Send 8 bits to the I2C Bus
{
byte <<= 1;
SCL = 1; // Clock the data into the I2C Bus
byte |= SDA; // Input the data from the I2C Bus
SCL = 0;
}

// Write ack bit
SDA = ACK;
SCL = 1; // Ensure that the data is stable during the high period.
SCL = 0;
return byte;
}

char i2c_readbyte(int data address)
{
char data byte;
if(!i2c_start())
{
outstr("i2c_start error: bus not free.\n");
return 0;
}
if(!i2c_write(DEVICEADD))
{
i2c_stop();
i2c_start();
if(!i2c_write(DEVICEADD)) // Interface failed to acknowledge device address
{
i2c_stop();
outstr("Interface failed to acknowledge device address.\n");
return 0;
}
}

// Transmit address to read from.
if(!i2c_write(address >> 8)) // Interface failed to acknowledge byteH address
{
i2c_stop();
outstr("Interface failed to acknowledge byteH address. \n");
return 0;
}
if(!i2c_write(address)) // Interface failed to acknowledge byteL address
{
i2c_stop();
outstr("Interface failed to acknowledge byteL address. \n");
return 0;
}

// Now terminate write operation and do a read.
if(!i2c_start())
{
outstr("i2c_start error: bus not free.\n");
return 0;
}
// Transmit address to read from.
if(!i2c_write(DEVICEADD | 1)) // Slave failed to ack read access
{
i2c_stop();
outstr("Slave failed to ack read access.\n");
return 0;
}
// Read from address and ack = 1.
byte = i2c_read(1);
i2c_stop();
return byte;
}

char get_char()
{
while(!RI)
{
}
RI = 0;
return SBUF;
}

void WriteData()
{
char data ch;
ch = get_char();
while(ch != 0x0D)
{
i2c_writebyte(c++,ch);
outchar(ch);
ch = get_char();
}
wrom = 0;
ES = 1;
}

void ReadData()
{
char data index;
char data input;
for(index = 0; index < c; index++)
{
input = i2c_readbyte(index);
if(input != 0)
outchar(input);
}
c = 0;
rrom = 0;
ES = 1;
}

void main(void)
{
// Init serial
SCON = 0x52;
// Set timer1 mode and reload value
TMOD &= ~0xF0; // clear timer 1 mode bits
TMOD |= 0x20; // put timer 1 into MODE 2 8 bit auto reload
TH1 = 0xFD;
TR1 = 1; // start timer 1
TI = 0;
ES = 1; // Enable Serial interrupt
EA = 1; // Enable all interrupts

c = 0;
rrom = 0;
wrom = 0;
DEVICEADD = 0xA0; // 10100000B
while(1)
{
if(wrom == 1)
{
outchar('W');
WriteData();
}
if(rrom == 1)
{
outchar('R');
ReadData();
}
/*
count = get_char();
outchar(count);
*/
}
}

void serial (void) interrupt 4 using 3
{
char data inp;
if(RI) // Received data interrupt
{
RI = 0;
inp = (char)SBUF;
if((inp == 'w') || (inp == 'W'))
{
ES = 0;
rrom = 0;
c = 0;
TI = 1;
wrom = 1;
}
else if((inp == 'r') || (inp == 'R'))
{
ES = 0;
wrom = 0;
TI = 1;
rrom = 1;
}
}
else if(TI) // Transmitted data interrupt
{
TI = 0;
}
}

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0 Jonh Bob over 18 years ago

Hello!
I have write a program to write and read to/from AT24c04 serial ROM (89C52 interface with AT24C04). I am using Keil C to program.

But i can read any data which i have write to AT24c04.
I don't know exacterly why.

My purpose is very simple. I listent from USART and get data from PC key board. If the character which i get from pc is 'w' or 'W' then i do get data from PC and write to AT24c04 until i get the 0x0D. Now if i get the 'r' or 'R' character from PC i read data which i have just write to AT24c04 and send back to PC.
But i can't read any.

Here is my code

#include <REG52.h>

unsigned char data DEVICEADD;

sbit SDA = P1^0;
sbit SCL = P1^1;

int data c;
char data wrom;
char data rrom;

void outchar(char data chr)
{
while(!TI)
{
}
TI = 0;
SBUF = chr;
}

void outstr(char* str)
{
while(*str != 0)
{
outchar(*str++);
}
}
char i2c_start(void)
{
/*
if(!SDA || !SCL)
return 0; // i2c_start error: bus not free
*/
// Both bus lines are high,
SDA = 0; // so set data line low to generate a start condition.
SCL = 0;
/*
SDA = 1;
SCL = 1;
SDA = 0;
SCL = 0;
*/
return 1;
}

void i2c_stop(void)
{
/*
SDA = 0;
SCL = 1;
SDA = 1;
*/
unsigned char input_var;
SCL = 1;
SDA = 0;
SCL = 1;
SDA = 1;
input_var = SDA;
}

// return ack value: 0 for fale; 1 for success
char i2c_write(char data byte)
{
int data i;
for(i = 0; i < 8 ; i++)
{
SDA = ((byte & 0x80) ? 1 : 0);
SCL = 1; // Ensure that the data is stable during the high period.
byte <<= 1;
SCL = 0;
}
// Get ack
SDA = 1;
SCL = 1;
i = SDA;
//i = 500;
SCL = 0;
/*
while(i-- && SDA)
{
}
*/
return !i; // Get data at end of cycle.
}

char i2c_writebyte(int data address, char data byte)
{
if(!i2c_start())
{
outstr("i2c_start error: bus not free.\n");
return 0;
}
if(!i2c_write(DEVICEADD))
{
i2c_stop();
i2c_start();
if(!i2c_write(DEVICEADD)) // Interface failed to acknowledge device address
{
i2c_stop();
outstr("Interface failed to acknowledge device address.\n");
return 0;
}
}

if(!i2c_write(address >>8)) // Interface failed to acknowledge byteH address
{
i2c_stop();
outstr("Interface failed to acknowledge byteH address.\n");
return 0;
}
if(!i2c_write(address)) // Interface failed to acknowledge byteL address
{
i2c_stop();
outstr("Interface failed to acknowledge byteL address.\n");
return 0;
}
if(!i2c_write(byte)) // Interface failed to acknowledge data
{
i2c_stop();
outstr("Interface failed to acknowledge data.\n");
return 0;
}
i2c_stop();
return 1; // success
}

char i2c_read(char data ACK)
{
char index, byte;
index = SDA; // Put data pin into read mode
byte = 0x00;
for(index = 0; index < 8; index++) // Send 8 bits to the I2C Bus
{
byte <<= 1;
SCL = 1; // Clock the data into the I2C Bus
byte |= SDA; // Input the data from the I2C Bus
SCL = 0;
}

// Write ack bit
SDA = ACK;
SCL = 1; // Ensure that the data is stable during the high period.
SCL = 0;
return byte;
}

char i2c_readbyte(int data address)
{
char data byte;
if(!i2c_start())
{
outstr("i2c_start error: bus not free.\n");
return 0;
}
if(!i2c_write(DEVICEADD))
{
i2c_stop();
i2c_start();
if(!i2c_write(DEVICEADD)) // Interface failed to acknowledge device address
{
i2c_stop();
outstr("Interface failed to acknowledge device address.\n");
return 0;
}
}

// Transmit address to read from.
if(!i2c_write(address >> 8)) // Interface failed to acknowledge byteH address
{
i2c_stop();
outstr("Interface failed to acknowledge byteH address. \n");
return 0;
}
if(!i2c_write(address)) // Interface failed to acknowledge byteL address
{
i2c_stop();
outstr("Interface failed to acknowledge byteL address. \n");
return 0;
}

// Now terminate write operation and do a read.
if(!i2c_start())
{
outstr("i2c_start error: bus not free.\n");
return 0;
}
// Transmit address to read from.
if(!i2c_write(DEVICEADD | 1)) // Slave failed to ack read access
{
i2c_stop();
outstr("Slave failed to ack read access.\n");
return 0;
}
// Read from address and ack = 1.
byte = i2c_read(1);
i2c_stop();
return byte;
}

char get_char()
{
while(!RI)
{
}
RI = 0;
return SBUF;
}

void WriteData()
{
char data ch;
ch = get_char();
while(ch != 0x0D)
{
i2c_writebyte(c++,ch);
outchar(ch);
ch = get_char();
}
wrom = 0;
ES = 1;
}

void ReadData()
{
char data index;
char data input;
for(index = 0; index < c; index++)
{
input = i2c_readbyte(index);
if(input != 0)
outchar(input);
}
c = 0;
rrom = 0;
ES = 1;
}

void main(void)
{
// Init serial
SCON = 0x52;
// Set timer1 mode and reload value
TMOD &= ~0xF0; // clear timer 1 mode bits
TMOD |= 0x20; // put timer 1 into MODE 2 8 bit auto reload
TH1 = 0xFD;
TR1 = 1; // start timer 1
TI = 0;
ES = 1; // Enable Serial interrupt
EA = 1; // Enable all interrupts

c = 0;
rrom = 0;
wrom = 0;
DEVICEADD = 0xA0; // 10100000B
while(1)
{
if(wrom == 1)
{
outchar('W');
WriteData();
}
if(rrom == 1)
{
outchar('R');
ReadData();
}
/*
count = get_char();
outchar(count);
*/
}
}

void serial (void) interrupt 4 using 3
{
char data inp;
if(RI) // Received data interrupt
{
RI = 0;
inp = (char)SBUF;
if((inp == 'w') || (inp == 'W'))
{
ES = 0;
rrom = 0;
c = 0;
TI = 1;
wrom = 1;
}
else if((inp == 'r') || (inp == 'R'))
{
ES = 0;
wrom = 0;
TI = 1;
rrom = 1;
}
}
else if(TI) // Transmitted data interrupt
{
TI = 0;
}
}

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0 steve robinson over 18 years ago in reply to Jonh Bob

I have just suceeded in connecting to a M24C08 from an Infineon C167.

Two things..

1 Your code shows two address bytes to the chip, the doc only shows one.

2 You must wait 5ms between a write and a read.

the code that worked for me was..

fnI2C_SendStart();
fnI2C_SendByte(0xA0); //device address write mode
fnI2C_SendByte(0); //lo address
fnI2C_SendByte(45); //a number
fnI2C_SendStop();

//wait for data line to go low
//this is awful i know
for (i=0;i<80;i++) // your 5ms delay here
{
fnDelay(127);
}

//read it from flash
//random access read according to st
fnI2C_SendStart();
fnI2C_SendByte(0xA0); //device address dummy write mode
fnI2C_SendByte(0);
fnI2C_SendStart();
fnI2C_SendByte(0xA1); // read

i = fnI2C_ReceiveByteNA(); //

fnI2C_SendStop();

..........
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0 Jonh Bob over 18 years ago in reply to steve robinson

Could you give me, your full source code, which you had test sucess.
Thanks.
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0 steve robinson over 18 years ago in reply to Jonh Bob

This is all the code for C167 to 24C08.

You will need to sort out your own 'printf' statement.

#define _MAIN_
/*********************************************************************/

/*********************************************************************/

#include <reg167.h>
#include <stdio.h>
#include <string.h>

//I2C values
#define INPUT DP2 = DP2 & 0xBFFF; //bit 14 of P2 used for I2C data line
#define OUTPUT DP2 = DP2 | 0xC000; // bit 14 is ourput , lets do bit 15 here as well!
#define SETCLOCK P2 = P2 | 0x8000; //bit 15 high
#define CLRCLOCK P2 = P2 & 0x7FFF; //bit 15 low
#define SETDATA P2 = P2 | 0x4000; //bit 14 high
#define CLRDATA P2 = P2 & 0xBFFF; //bit 14 low
#define BOTHHIGH P2 = P2 | 0xC000; //bits 14 and 15 high
#define BOTHLOW P2 = P2 & 0x3FFF;
#define RD 0x01;
#define WR 0x00;

/* global */
unsigned char delayfull;
unsigned char delayhalf;
unsigned char onebit[16];
unsigned char rx;

/*** Executable Functions ***/
void fnDelay(unsigned char mydelay)
{
unsigned char uchCounter;
for(uchCounter = 0; uchCounter < mydelay; uchCounter ++); //need to play with this
}

void fnI2C_SendStart()
{
OUTPUT
SETDATA
SETCLOCK
fnDelay(delayhalf);
CLRDATA
fnDelay(delayhalf);
CLRCLOCK
fnDelay(delayhalf);
}

void fnI2C_SendStop()
{
OUTPUT
BOTHLOW
SETCLOCK
fnDelay(delayhalf);
SETDATA
fnDelay(delayhalf);
CLRCLOCK
fnDelay(delayhalf);
}

//receive byte function

/* Read Byte */

unsigned char fnI2C_ReceiveByte()
{
unsigned char uchBitCounter;
unsigned char uchBitSelection;

INPUT

uchBitSelection=0x00;

for(uchBitCounter=0;uchBitCounter<8;uchBitCounter++)
{
SETCLOCK
fnDelay(delayfull);

if((P2 & 0x4000) > 0) //looking for data on bit 14

uchBitSelection|=0x01;

if(uchBitCounter<7)
uchBitSelection<<=1;

fnDelay(delayfull);
CLRCLOCK
fnDelay(delayfull);
}

OUTPUT
CLRDATA
fnDelay(delayfull);
SETCLOCK
fnDelay(delayfull);
CLRCLOCK
INPUT

return uchBitSelection;
}

unsigned char fnI2C_ReceiveByteNA()
{
unsigned char uchBitCounter;
unsigned char uchBitSelection;

INPUT

uchBitSelection=0x00;

for(uchBitCounter=0;uchBitCounter<8;uchBitCounter++)
{
SETCLOCK
fnDelay(delayfull);
if((P2 & 0x4000) > 0) // is bit 14 held high then the data is a 1
uchBitSelection|=0x01;

if(uchBitCounter<7)
uchBitSelection<<=1;

fnDelay(delayfull);
CLRCLOCK
fnDelay(delayfull);
}

SETCLOCK
fnDelay(delayfull);
CLRCLOCK

return uchBitSelection;
}

/* Send Byte */

unsigned char fnI2C_SendByte(unsigned char uchByte)
{
unsigned char uchBitCounter;
unsigned char uchBitSelection;

OUTPUT

uchBitSelection = 0x80;

for(uchBitCounter = 0; uchBitCounter <8; uchBitCounter ++)
{
if(uchByte & uchBitSelection)
SETDATA
else
CLRDATA

uchBitSelection >>= 1;

SETCLOCK
fnDelay(delayfull);
CLRCLOCK
fnDelay(delayfull);
CLRDATA
}
CLRDATA //august
INPUT
SETCLOCK
fnDelay(delayfull);
// should check if acknowledge is received uchBitSelection = _PTA.Byte;
CLRCLOCK

uchBitSelection ^= 0xFF;
uchBitSelection &= 0x08; //20 SHOULD BE 08
fnDelay(delayfull);
//return uchBitSelection;
}

/* Function Definitions */

// Main Function Entered From Reset

void main (void) {

unsigned char i;
long x;

delayfull = 8;//play with these to get the i2c repetition rate
delayhalf = 4;

DP2 = 0xFF00;

P2 = P2 & 0x00FF; //clear top 8 bits

IEN = 1; /* Enable Interrupts (for monitor) */

//write one byte to flash
fnI2C_SendStart();
fnI2C_SendByte(0xA0); //device address write mode
fnI2C_SendByte(0); //lo address
fnI2C_SendByte(45); //a number
fnI2C_SendStop();

//nasty - should check for something in the chip
//wait for data line to go low

for (i=0;i<80;i++) //worked at 100 and 80 and 60, failed at 40
{
fnDelay(127);
}

//read it from flash
//random access read according to st
fnI2C_SendStart();
fnI2C_SendByte(0xA0); //device address write mode
fnI2C_SendByte(0);
fnI2C_SendStart();
fnI2C_SendByte(0xA1); // read

i = fnI2C_ReceiveByteNA(); //NA??

fnI2C_SendStop();

printf("%d",i);

/* Loop forever */

while(1)
{

} // end of while forever loop

} //end of main

....

good luck

steve robinson
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0 saeid maleki over 18 years ago in reply to Jonh Bob

i want example code c51 for read and write

24c02
tank you!
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0 erik malund over 18 years ago in reply to saeid maleki

i want example code c51 for read and write 24c02

once more:

GIMME CODE!!

Eventually all us old farts will pass and what are you young whippersnappers that have been given finished code every time gonna do then. You never learned to code your own and there will be nobody to give it to you.

Try coding your own, and post the specific problems with your OWN code here and help will be forthcoming.

ALSO: how do you propose that anyone can help you when you see no need to specify what uC you are using (specific derivative), not to mention that the 24c02 is NOT totally identical from manufacturer to manufacturer.

Erik
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