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crc8.c File Reference

#include <stdio.h>

Go to the source code of this file.

Defines

#define GP   0x107
#define DI   0x07

Functions

void init_crc8 ()
void crc8 (unsigned char *crc, unsigned char m)

Variables

unsigned char crc8_table [256]
int made_table = 0

Define Documentation

#define DI   0x07
 

Definition at line 12 of file crc8.c.

#define GP   0x107
 

Definition at line 11 of file crc8.c.

Function Documentation

void crc8 (  unsigned char *  crc,
unsigned char  m
) 
 

Definition at line 39 of file crc8.c.

References crc8_table, and init_crc8().

Referenced by get_al_pdu(), and send_closing_flag().

00044 {
00045   if (!made_table)
00046     init_crc8();
00047 
00048   *crc = crc8_table[(*crc) ^ m];
00049   *crc &= 0xFF;
00050 }

void init_crc8 (   )  [static]
 

Definition at line 18 of file crc8.c.

References crc8_table, DI, and made_table.

Referenced by crc8().

00022 {
00023   int i,j;
00024   unsigned char crc;
00025   
00026   if (!made_table) {
00027     for (i=0; i<256; i++) {
00028       crc = i;
00029       for (j=0; j<8; j++)
00030         crc = (crc << 1) ^ ((crc & 0x80) ? DI : 0);
00031       crc8_table[i] = crc & 0xFF;
00032       /* printf("table[%d] = %d (0x%X)\n", i, crc, crc); */
00033     }
00034     made_table=1;
00035   }
00036 }

Variable Documentation

unsigned char crc8_table[256] [static]
 

Definition at line 15 of file crc8.c.

Referenced by crc8(), and init_crc8().

int made_table = 0 [static]
 

Definition at line 16 of file crc8.c.

Referenced by init_crc8().

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