core/lib/me.h

   1 /*
   2  * Copyright (c) 2005, Swedish Institute of Computer Science
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the Institute nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * This file is part of the Contiki operating system.
  30  *
  31  * @(#)$Id: me.h,v 1.1 2006/06/17 22:41:18 adamdunkels Exp $
  32  */
  33
  34 /** \addtogroup lib
  35     @{ */
  36
  37 /**
  38  * \defgroup me Table-driven Manchester encoding and decoding
  39  *
  40  * Manchester encoding is a bit encoding scheme which translates each
  41  * bit into two bits: the original bit and the inverted bit.
  42  *
  43  * Manchester encoding is used for transmitting ones and zeroes
  44  * between two computers. The Manchester encoding reduces the receive
  45  * oscillator drift by making sure that no consecutive ones or zeroes
  46  * are ever transmitted.
  47  *
  48  * The table driven method of Manchester encoding and decoding uses
  49  * two tables with 256 entries. One table is a direct mapping of an
  50  * 8-bit byte into a 16-bit Manchester encoding of the byte. The
  51  * second table is a mapping of a Manchester encoded 8-bit byte to 4
  52  * decoded bits.
  53  *
  54  * @{
  55  */
  56
  57 /**
  58  * \file
  59  * Header file for the table-driven Manchester encoding and decoding
  60  * \author
  61  * Adam Dunkels <adam@sics.se>
  62  *
  63  */
  64
  65 #ifndef __ME_H__
  66 #define __ME_H__
  67
  68 unsigned char  me_valid(unsigned char m);
  69 unsigned short me_encode(unsigned char c);
  70 unsigned char  me_decode16(unsigned short m);
  71 unsigned char  me_decode8(unsigned char m);
  72
  73 #endif /* __ME_H__ */
  74
  75 /** @} */
  76 /** @} */