Hi ,

You tell me in the second message what code I have to added it. I created a global var named unsigned char i2cVector[30]; And created also two more variables unsigned int: IndexTx and IndexRx, to pointed to correct variable position.

In the Callback rotines, I did it:

unsigned char i2c_master_getbyte(unsigned int bytenum)
{
    return i2cVector[bytenum];
}

void i2c_master_receivedbyte(unsigned int bytenum, unsigned char value)
{
  i2cVector[bytenum]=value;
}

unsigned char i2c_master_islasttxbyte(unsigned int bytenum)
{
  if(bytenum==(IndexTx-1))
    return(1);
  else
    return(0);
}

unsigned char i2c_master_islastrxbyte(unsigned int bytenum)
{
  if(bytenum==(IndexRx-1))
    return(1);
  else
    return(0);
}

void i2c_transfer_finished(void)
{
  IndexTx=0;
  IndexRx=0;
}

I didn't change anything in the others functions.
Are anything correct code ?

Now, I'm trying to write a byte using :

#define AT24C256 0x50	// 0101 0000

void main(void)
{
  i2c_init(0x00, 0);
  EA=1;
  IndexTx=3;   // bytes to write to memory
  i2cVector[0]=0x00;
  i2cVector[1]=0x00;
  i2cVector[2]=0x5A;
  while(1)
  {
     if (i2c_getstatus() == I2C_OK)
       i2c_transmit(AT24C256);
     IndexRx=1;  // bytes to read from memory
     if (i2c_getstatus() == I2C_OK)
       i2c_receive(AT24C256);
  }
  while(1);
}

Are these anything correct code?

I undestood how the I2C interrupt work. The I2C interrupt is called a lot of time to transmit a sigle byte. (start condition, putting address slave in i2c bus, putting address e2prom (high and low), putting data to write and finally, stop condition.

Is it correct ?

Jorge