Contiki 3.x
me.h
Go to the documentation of this file.
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  */
32 
33 /** \addtogroup lib
34  @{ */
35 
36 /**
37  * \defgroup me Table-driven Manchester encoding and decoding
38  *
39  * Manchester encoding is a bit encoding scheme which translates each
40  * bit into two bits: the original bit and the inverted bit.
41  *
42  * Manchester encoding is used for transmitting ones and zeroes
43  * between two computers. The Manchester encoding reduces the receive
44  * oscillator drift by making sure that no consecutive ones or zeroes
45  * are ever transmitted.
46  *
47  * The table driven method of Manchester encoding and decoding uses
48  * two tables with 256 entries. One table is a direct mapping of an
49  * 8-bit byte into a 16-bit Manchester encoding of the byte. The
50  * second table is a mapping of a Manchester encoded 8-bit byte to 4
51  * decoded bits.
52  *
53  * @{
54  */
55 
56 /**
57  * \file
58  * Header file for the table-driven Manchester encoding and decoding
59  * \author
60  * Adam Dunkels <adam@sics.se>
61  *
62  */
63 
64 #ifndef ME_H_
65 #define ME_H_
66 
67 unsigned char me_valid(unsigned char m);
68 unsigned short me_encode(unsigned char c);
69 unsigned char me_decode16(unsigned short m);
70 unsigned char me_decode8(unsigned char m);
71 
72 #endif /* ME_H_ */
73 
74 /** @} */
75 /** @} */
unsigned char me_decode16(unsigned short m)
Decode a Manchester encoded 16-bit word.
Definition: me.c:75
unsigned char me_valid(unsigned char m)
Check if an encoded byte is valid.
Definition: me.c:109
unsigned short me_encode(unsigned char c)
Manchester encode an 8-bit byte.
Definition: me.c:58
unsigned char me_decode8(unsigned char m)
Decode a Manchester encoded 8-bit byte.
Definition: me.c:99