nes-proj/core/lib/me.h

76 lines
2.7 KiB
C

/*
* Copyright (c) 2005, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
*/
/** \addtogroup lib
@{ */
/**
* \defgroup me Table-driven Manchester encoding and decoding
*
* Manchester encoding is a bit encoding scheme which translates each
* bit into two bits: the original bit and the inverted bit.
*
* Manchester encoding is used for transmitting ones and zeroes
* between two computers. The Manchester encoding reduces the receive
* oscillator drift by making sure that no consecutive ones or zeroes
* are ever transmitted.
*
* The table driven method of Manchester encoding and decoding uses
* two tables with 256 entries. One table is a direct mapping of an
* 8-bit byte into a 16-bit Manchester encoding of the byte. The
* second table is a mapping of a Manchester encoded 8-bit byte to 4
* decoded bits.
*
* @{
*/
/**
* \file
* Header file for the table-driven Manchester encoding and decoding
* \author
* Adam Dunkels <adam@sics.se>
*
*/
#ifndef ME_H_
#define ME_H_
unsigned char me_valid(unsigned char m);
unsigned short me_encode(unsigned char c);
unsigned char me_decode16(unsigned short m);
unsigned char me_decode8(unsigned char m);
#endif /* ME_H_ */
/** @} */
/** @} */