M24LR64-R_1006 Datasheet, PDF (125/128 Pages) STMicroelectronics – 64 Kbit EEPROM with password protection & dual interface

M24LR64-R
CRC (informative)
number_of_databytes = NUMBER_OF_BYTES;
}
else // check CRC
{
number_of_databytes = NUMBER_OF_BYTES + 2;
}
current_crc_value = PRESET_VALUE;
for (i = 0; i < number_of_databytes; i++)
{
current_crc_value = current_crc_value ^ ((unsigned
int)array_of_databytes[i]);
for (j = 0; j < 8; j++)
{
if (current_crc_value & 0x0001)
{
current_crc_value = (current_crc_value >> 1) ^
POLYNOMIAL;
}
else
{
current_crc_value = (current_crc_value >> 1);
}
}
}
if (calculate_or_check_crc == CALC_CRC)
{
current_crc_value = ~current_crc_value;
printf ("Generated CRC is 0x%04X\n", current_crc_value);
// current_crc_value is now ready to be appended to the data
stream
// (first LSByte, then MSByte)
}
else // check CRC
{
if (current_crc_value == CHECK_VALUE)
{
printf ("Checked CRC is ok (0x%04X)\n",
current_crc_value);
}
else
{
printf ("Checked CRC is NOT ok (0x%04X)\n",
current_crc_value);
}
}
}
Doc ID 15170 Rev 10
125/128