git.zerfleddert.de Git - proxmark3-svn/blob - common/crc16.c

   1 #include "crc16.h"
   2
   3 unsigned short update_crc16( unsigned short crc, unsigned char c )
   4 {
   5   unsigned short i, v, tcrc = 0;
   6
   7   v = (crc ^ c) & 0xff;
   8   for (i = 0; i < 8; i++) {
   9       tcrc = ( (tcrc ^ v) & 1 ) ? ( tcrc >> 1 ) ^ 0x8408 : tcrc >> 1;
  10       v >>= 1;
  11   }
  12
  13   return ((crc >> 8) ^ tcrc)&0xffff;
  14 }