// $Id: crc.h,v 1.5 2004/09/20 20:51:02 jpolastre Exp $

/*									tab:4
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 * Copyright (c) 2002-2003 Intel Corporation
 * All rights reserved.
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/**
 * Default CRC function. Note that avrmote has a much more efficient one. 
 *
 * This CRC-16 function produces a 16-bit running CRC that adheres to the
 * ITU-T CRC standard.
 *
 * The ITU-T polynomial is: G_16(x) = x^16 + x^12 + x^5 + 1
 *
 */

uint16_t crcByte(uint16_t crc, uint8_t b)
{
  uint8_t i;
  
  crc = crc ^ b << 8;
  i = 8;
  do
    if (crc & 0x8000)
      crc = crc << 1 ^ 0x1021;
    else
      crc = crc << 1;
  while (--i);

  return crc;
}