38
|
1 ///////////////////////////////////////////////////////////////////////////////
|
|
2 /// -*- coding: UTF-8 -*-
|
|
3 ///
|
|
4 /// \file Discovery/Inc/crcmodel.h
|
|
5 /// \brief Rocksoft CRC Model Algorithm
|
|
6 /// \author Ross Williams (ross@guest.adelaide.edu.au.) and Heinrichs Weikamp
|
|
7 /// \date 3 June 1993
|
|
8 ///
|
|
9 /// \details
|
|
10 ///
|
|
11 /// This is the header (.h) file for the reference
|
|
12 /// implementation of the Rocksoft^tm Model CRC Algorithm. For more
|
|
13 /// information on the Rocksoft^tm Model CRC Algorithm, see the document
|
|
14 /// titled "A Painless Guide to CRC Error Detection Algorithms" by Ross
|
|
15 /// Williams (ross@guest.adelaide.edu.au.). This document is likely to be in
|
|
16 /// "ftp.adelaide.edu.au/pub/rocksoft".
|
|
17 ///
|
|
18 /// Note: Rocksoft is a trademark of Rocksoft Pty Ltd, Adelaide, Australia.
|
|
19 ///
|
|
20 /// $Id$
|
|
21 ///////////////////////////////////////////////////////////////////////////////
|
|
22 /// \par Copyright (c) 2014-2018 Heinrichs Weikamp gmbh
|
|
23 ///
|
|
24 /// This program is free software: you can redistribute it and/or modify
|
|
25 /// it under the terms of the GNU General Public License as published by
|
|
26 /// the Free Software Foundation, either version 3 of the License, or
|
|
27 /// (at your option) any later version.
|
|
28 ///
|
|
29 /// This program is distributed in the hope that it will be useful,
|
|
30 /// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
31 /// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
32 /// GNU General Public License for more details.
|
|
33 ///
|
|
34 /// You should have received a copy of the GNU General Public License
|
|
35 /// along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
36 //////////////////////////////////////////////////////////////////////////////
|
|
37
|
|
38 /******************************************************************************/
|
|
39 /* Start of crcmodel.h */
|
|
40 /******************************************************************************/
|
|
41 /* */
|
|
42 /* Author : Ross Williams (ross@guest.adelaide.edu.au.). */
|
|
43 /* Date : 3 June 1993. */
|
|
44 /* Status : Public domain. */
|
|
45 /* */
|
|
46 /* Description : This is the header (.h) file for the reference */
|
|
47 /* implementation of the Rocksoft^tm Model CRC Algorithm. For more */
|
|
48 /* information on the Rocksoft^tm Model CRC Algorithm, see the document */
|
|
49 /* titled "A Painless Guide to CRC Error Detection Algorithms" by Ross */
|
|
50 /* Williams (ross@guest.adelaide.edu.au.). This document is likely to be in */
|
|
51 /* "ftp.adelaide.edu.au/pub/rocksoft". */
|
|
52 /* */
|
|
53 /* Note: Rocksoft is a trademark of Rocksoft Pty Ltd, Adelaide, Australia. */
|
|
54 /* */
|
|
55 /******************************************************************************/
|
|
56 /* */
|
|
57 /* How to Use This Package */
|
|
58 /* ----------------------- */
|
|
59 /* Step 1: Declare a variable of type cm_t. Declare another variable */
|
|
60 /* (p_cm say) of type p_cm_t and initialize it to point to the first */
|
|
61 /* variable (e.g. p_cm_t p_cm = &cm_t). */
|
|
62 /* */
|
|
63 /* Step 2: Assign values to the parameter fields of the structure. */
|
|
64 /* If you don't know what to assign, see the document cited earlier. */
|
|
65 /* For example: */
|
|
66 /* p_cm->cm_width = 16; */
|
|
67 /* p_cm->cm_poly = 0x8005L; */
|
|
68 /* p_cm->cm_init = 0L; */
|
|
69 /* p_cm->cm_refin = TRUE; */
|
|
70 /* p_cm->cm_refot = TRUE; */
|
|
71 /* p_cm->cm_xorot = 0L; */
|
|
72 /* Note: Poly is specified without its top bit (18005 becomes 8005). */
|
|
73 /* Note: Width is one bit less than the raw poly width. */
|
|
74 /* */
|
|
75 /* Step 3: Initialize the instance with a call cm_ini(p_cm); */
|
|
76 /* */
|
|
77 /* Step 4: Process zero or more message bytes by placing zero or more */
|
|
78 /* successive calls to cm_nxt. Example: cm_nxt(p_cm,ch); */
|
|
79 /* */
|
|
80 /* Step 5: Extract the CRC value at any time by calling crc = cm_crc(p_cm); */
|
|
81 /* If the CRC is a 16-bit value, it will be in the bottom 16 bits. */
|
|
82 /* */
|
|
83 /******************************************************************************/
|
|
84 /* */
|
|
85 /* Design Notes */
|
|
86 /* ------------ */
|
|
87 /* PORTABILITY: This package has been coded very conservatively so that */
|
|
88 /* it will run on as many machines as possible. For example, all external */
|
|
89 /* identifiers have been restricted to 6 characters and all internal ones to */
|
|
90 /* 8 characters. The prefix cm (for Crc Model) is used as an attempt to avoid */
|
|
91 /* namespace collisions. This package is endian independent. */
|
|
92 /* */
|
|
93 /* EFFICIENCY: This package (and its interface) is not designed for */
|
|
94 /* speed. The purpose of this package is to act as a well-defined reference */
|
|
95 /* model for the specification of CRC algorithms. If you want speed, cook up */
|
|
96 /* a specific table-driven implementation as described in the document cited */
|
|
97 /* above. This package is designed for validation only; if you have found or */
|
|
98 /* implemented a CRC algorithm and wish to describe it as a set of parameters */
|
|
99 /* to the Rocksoft^tm Model CRC Algorithm, your CRC algorithm implementation */
|
|
100 /* should behave identically to this package under those parameters. */
|
|
101 /* */
|
|
102 /******************************************************************************/
|
|
103
|
|
104 #ifndef CRC_MODEL_H
|
|
105 #define CRC_MODEL_H
|
|
106
|
|
107 /******************************************************************************/
|
|
108
|
|
109 /* The following definitions are extracted from my style header file which */
|
|
110 /* would be cumbersome to distribute with this package. The DONE_STYLE is the */
|
|
111 /* idempotence symbol used in my style header file. */
|
|
112
|
|
113 #ifndef DONE_STYLE
|
|
114
|
776
45b8f3c2acce
Add support for a configurable compass declination in a range of -99 to 99 degrees.
heinrichsweikamp
diff
changeset
|
115 #include <stdbool.h>
|
45b8f3c2acce
Add support for a configurable compass declination in a range of -99 to 99 degrees.
heinrichsweikamp
diff
changeset
|
116
|
38
|
117 typedef unsigned long ulong;
|
|
118 typedef unsigned char * p_ubyte_;
|
|
119
|
|
120 #ifndef TRUE
|
|
121 #define FALSE 0
|
|
122 #define TRUE 1
|
|
123 #endif
|
|
124
|
|
125 /* Change to the second definition if you don't have prototypes. */
|
|
126 #define P_(A) A
|
|
127 /* #define P_(A) () */
|
|
128
|
|
129 /* Uncomment this definition if you don't have void. */
|
|
130 /* typedef int void; */
|
|
131
|
|
132 #endif
|
|
133
|
|
134 /******************************************************************************/
|
|
135
|
|
136 /* CRC Model Abstract Type */
|
|
137 /* ----------------------- */
|
|
138 /* The following type stores the context of an executing instance of the */
|
|
139 /* model algorithm. Most of the fields are model parameters which must be */
|
|
140 /* set before the first initializing call to cm_ini. */
|
|
141 typedef struct
|
|
142 {
|
|
143 int cm_width; /* Parameter: Width in bits [8,32]. */
|
|
144 ulong cm_poly; /* Parameter: The algorithm's polynomial. */
|
|
145 ulong cm_init; /* Parameter: Initial register value. */
|
|
146 bool cm_refin; /* Parameter: Reflect input bytes? */
|
|
147 bool cm_refot; /* Parameter: Reflect output CRC? */
|
|
148 ulong cm_xorot; /* Parameter: XOR this to output CRC. */
|
|
149
|
|
150 ulong cm_reg; /* Context: Context during execution. */
|
|
151 } cm_t;
|
|
152 typedef cm_t *p_cm_t;
|
|
153
|
|
154 /******************************************************************************/
|
|
155
|
|
156 /* Functions That Implement The Model */
|
|
157 /* ---------------------------------- */
|
|
158 /* The following functions animate the cm_t abstraction. */
|
|
159
|
|
160 void cm_ini P_((p_cm_t p_cm));
|
|
161 /* Initializes the argument CRC model instance. */
|
|
162 /* All parameter fields must be set before calling this. */
|
|
163
|
|
164 void cm_nxt P_((p_cm_t p_cm,int ch));
|
|
165 /* Processes a single message byte [0,255]. */
|
|
166
|
|
167 void cm_blk P_((p_cm_t p_cm,p_ubyte_ blk_adr,ulong blk_len));
|
|
168 /* Processes a block of message bytes. */
|
|
169
|
|
170 ulong cm_crc P_((p_cm_t p_cm));
|
|
171 /* Returns the CRC value for the message bytes processed so far. */
|
|
172
|
|
173 /******************************************************************************/
|
|
174
|
|
175 /* Functions For Table Calculation */
|
|
176 /* ------------------------------- */
|
|
177 /* The following function can be used to calculate a CRC lookup table. */
|
|
178 /* It can also be used at run-time to create or check static tables. */
|
|
179
|
|
180 ulong cm_tab P_((p_cm_t p_cm,int index));
|
|
181 /* Returns the i'th entry for the lookup table for the specified algorithm. */
|
|
182 /* The function examines the fields cm_width, cm_poly, cm_refin, and the */
|
|
183 /* argument table index in the range [0,255] and returns the table entry in */
|
|
184 /* the bottom cm_width bytes of the return value. */
|
|
185
|
|
186 /******************************************************************************/
|
|
187
|
|
188 #endif // CRC_MODEL_H
|