Problema con checksum

ibonh · #1 (**permalink**) 30/04/2009, 01:06

Hola:

Los fabricantes de un dispositivo me han enviado este programa en C para el checsum de una comunicacion en 422.
Mi problema es que no puedo compilarlo. ¿Me podeis echar una mano?

//“C” code example for the CRC calculation (RS>232/RS>422)
//Example C code to calculate a CRC sum:
/*
************************************************** ************************
Project: generic project
File: crc16c.c
CRC16 calculation
Version: V0.0.1
Date: 20.09.1998
************************************************** ************************
Abstract:
routines for calculating a 16 bits CRC signature using the generator
polynom x^16 + x^12 + x^5 + 1 as recommended by the ITU.T V.42
(former CCITT); all routines use a table driven algorithm
--------------------------------------------------------------------------
Modification History:
0.0.1 20.09.1998
created
************************************************** ************************/
#define CRC16C_C
// includes
#include "cpu-dep.h"
//
================================================== =================
// local scope defines
// (global scope in seperate header file: this_file.h)
//
================================================== =================
// local scope macros
// (global macros in seperate header file: this_file.h)
//
================================================== =================
// local scope type definitions
// (global scope in seperate header file: this_file.h)
//
================================================== =================
// local scope prototype declarations (type modifier: PRIVATE)
// (global scope in seperate header file: this_file.h)
//
================================================== =================
// global scope global variable definitions (type modifier: PUBLIC)
//
================================================== =================
// local scope global variable definitions (type modifier: PRIVATE)
// XOR table for CRC algorithm, CRC-16, ITU.T X.25
// polynomial: h1021
PRIVATE const WORD crctab[256] =
{
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};
//
================================================== =================
// global scope function definitions (type modifier: PUBLIC)
/*
--------------------------------------------------------------------------
Function: block_crc16_byte
Abstract: calculates CRC16 signature of a block of bytes
Version: 1
--------------------------------------------------------------------------
Return value:
type functional description
WORD CRC signature
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Importlist:
type identifier functional description
BYTE* data pointer to data block
WORD numofbytes number of bytes in data block
WORD initial_crc initial CRC value
WORD[] crctab CRC XOR table (as global variable)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Exportlist:
type identifier functional description
none
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
PUBLIC WORD block_crc16_byte
(
BYTE* data,
WORD numofbytes,
WORD initial_crc
)
{
WORD crc = initial_crc;
while( numofbytes-- )
crc = ( (crc << 8) | *data++ ) ^ crctab[crc>>8];
return crc;
}
/*
--------------------------------------------------------------------------
Function: block_crc16_word
Abstract: calculates CRC16 signature of a block of data words (16bit)
Version: 1
--------------------------------------------------------------------------
Return value:
type functional description
WORD CRC signature
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Importlist:
type identifier functional description
WORD* data pointer to data block
WORD numofbytes number of bytes (not words!) in data block
WORD initial_crc initial CRC value
WORD[] crctab CRC XOR table (as global variable)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Exportlist:
type identifier functional description
none
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
PUBLIC WORD block_crc16_word
(
WORD* data,
WORD numofbytes,
WORD initial_crc
)
{
register WORD d;
register WORD crc = initial_crc;
numofbytes >>= 1;
while( numofbytes-- )
{
d = *data++;
crc = ( (crc << 8) | ((BYTE)( d >> 8 ) ) ) ^ crctab[crc>>8];
crc = ( (crc << 8) | ((BYTE) d )) ^ crctab[crc>>8];
}
return crc;
}
/*
--------------------------------------------------------------------------
Function: crc16_byte
Abstract: calculates CRC16 signature of a single data byte
Version: 1
--------------------------------------------------------------------------
Return value:
type functional description
WORD CRC signature
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Importlist:
type identifier functional description
BYTE data data byte
WORD initial_crc initial CRC value
WORD[] crctab CRC XOR table (as global variable)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Exportlist:
type identifier functional description
none
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
PUBLIC WORD crc16_byte
(
BYTE data,
WORD initial_crc
)
{
register WORD crc = initial_crc;
crc = ( (crc << 8) | data ) ^ crctab[crc>>8];
return crc;
}
/*
--------------------------------------------------------------------------
Function: crc16_word
Abstract: calculates CRC16 signature of a single data word (16bit)
Version: 1
--------------------------------------------------------------------------
Return value:
type functional description
WORD CRC signature
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Importlist:
type identifier functional description
WORD data data word
WORD initial_crc initial CRC value
WORD[] crctab CRC XOR table (as global variable)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Exportlist:
type identifier functional description
none
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
PUBLIC WORD crc16_word
(
WORD data,
WORD initial_crc
)
{
register WORD crc = initial_crc;
crc = ( (crc << 8) | ((BYTE)( data >> 8 ) ) ) ^ crctab[crc>>8];
crc = ( (crc << 8) | ((BYTE) data )) ^ crctab[crc>>8];
return crc;
}
//
================================================== =================
// local scope function definitions (type modifier: PRIVATE)
//
================================================== =================
// EOF crc16c.c
Example C code to generate the CRC table used in the example above:
#include <stdio.h>
#define CRC_POLY 0x1021
typedef unsigned short WORD;
WORD get_crctab_val
(
int idx
)
{
WORD value;
WORD old_val;
int k;
value = ( (WORD) idx ) << 8;
for( k=0; k<8; k++ )
{
old_val = value;
value <<= 1;
if( old_val & 0x8000 ) value ^= CRC_POLY;
}
return value;
}
void main( void )
{
FILE *out;
WORD value;
int k, i;
out = fopen( "crctab.c", "wt" );
if( out == NULL )
{
puts( "\ncannot generate crctab.c !!\n\n" );
return;
}
fprintf( out, "// put header here\n\n" );
fprintf( out, "#include \"cpu-dep.h\"\n\n" );
fprintf( out, "// XOR table for CRC algorithm, CRC-16, ITU.T X.25\n" );
fprintf( out, "// polynomial: h%4x\n\n", CRC_POLY );
fprintf( out, "const WORD crctab[256] = \n" );
fprintf( out, " {" );
i = 0;
for( k=0; k<256; k++ )
{
value = get_crctab_val( k );
if( i == 0 )
fprintf( out, "\n 0x%04x,", value );
else if( k >= 248 && i >= 7 )
fprintf( out, " 0x%04x", value );
else
fprintf( out, " 0x%04x,", value );
if( ++i >= 8 ) i = 0;
}
fprintf( out, "\n };\n\n" );
fclose( out );
}

Eternal Idol · #2 (**permalink**) 30/04/2009, 01:38

¿Tenes la cabecera cpu-dep.h?

Yo la cree asi para compilar COMPILAR (mas no enlazar el primer modulo):

Código:

typedef unsigned short WORD;
typedef unsigned char BYTE;
#define PRIVATE
#define PUBLIC

Y el segundo modulo compila y genera el ejecutable sin problemas.

ibonh · #3 (**permalink**) 30/04/2009, 02:36

Hola:
Perdona mi ignoracia en este tema

Me comentas que sustituya esto:

#define CRC16C_C
// includes
#include "cpu-dep.h"

por esto otro:

typedef unsigned short WORD;
typedef unsigned char BYTE;
#define PRIVATE
#define PUBLIC

y compilarlo???
gracias

Eternal Idol · #4 (**permalink**) 30/04/2009, 04:02

Eso fue lo que hice al no tener la cabecera cpu-dep.h, pero quiero creer que vos si la tenes.

ibonh · #5 (**permalink**) 30/04/2009, 04:11

Hola:
No, yo no la tengo ya que este es el ejemplo integro que nos da el fabricante.
Lo he comprobado y compilando me da un ejecutable que al ejecutarlo no hace nada.

Eternal Idol · #6 (**permalink**) 30/04/2009, 05:08

Si hace algo, crea un archivo llamado crctab.c ...