crc16.h revision 969f7ed32353ade93ea30542a4993b75b94e3f8a
1969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe/*
2969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe *	crc16.h - CRC-16 routine
3969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe *
4969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe * Implements the standard CRC-16:
5969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe *   Width 16
6969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe *   Poly  0x8005 (x^16 + x^15 + x^2 + 1)
7969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe *   Init  0
8969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe *
9969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
10969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe *
11969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe * This source code is licensed under the GNU General Public License,
12969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe * Version 2. See the file COPYING for more details.
13969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe */
14969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe
15969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe#ifndef __CRC16_H
16969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe#define __CRC16_H
17969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe
18969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboeextern unsigned short const crc16_table[256];
19969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe
20969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboeextern unsigned short crc16(const unsigned char *buffer, unsigned int len);
21969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe
22969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboestatic inline unsigned short crc16_byte(unsigned short crc,
23969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe					const unsigned char data)
24969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe{
25969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe	return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff];
26969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe}
27969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe
28969f7ed32353ade93ea30542a4993b75b94e3f8aJens Axboe#endif /* __CRC16_H */
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