proxmark3/common/crc16.c
marcansoft bd20f8f478 Add license headers to armsrc/bootrom/common stuff
I have kept whatever copyright notices exist. Please add your own
copyright notice if you have made any nontrivial changes or additions to
the code. There are several files without any attribution, currently.
2010-02-21 00:12:52 +00:00

22 lines
727 B
C

//-----------------------------------------------------------------------------
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// CRC16
//-----------------------------------------------------------------------------
#include "crc16.h"
unsigned short update_crc16( unsigned short crc, unsigned char c )
{
unsigned short i, v, tcrc = 0;
v = (crc ^ c) & 0xff;
for (i = 0; i < 8; i++) {
tcrc = ( (tcrc ^ v) & 1 ) ? ( tcrc >> 1 ) ^ 0x8408 : tcrc >> 1;
v >>= 1;
}
return ((crc >> 8) ^ tcrc)&0xffff;
}