Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!gate.ready.com!gate.ready.com!glenn
From: glenn@ready.com (Glenn Kasten)
Newsgroups: comp.sources.wanted
Subject: Re: CRC-16 source code wanted
Message-ID: <1991Apr23.225034.17488@ready.eng.ready.com>
Date: 23 Apr 91 22:50:34 GMT
References: <461@frcs.UUCP>
Sender: glenn@ready.eng.ready.com (Glenn Kasten)
Reply-To: glenn@ready.com (Glenn Kasten)
Distribution: comp
Organization: Ready Systems
Lines: 30


In article <461@frcs.UUCP>, paul@frcs.UUCP (Paul Nash) writes:
|> 
|> I am looking for C source code to implement the CRC-16 algorithm.

/* CRC-16 cyclic redundancy check algorithm */

void crc16(data_buffer, nbytes, crc_buffer)
char *data_buffer, crc_buffer[2];
unsigned nbytes;
{
    unsigned crc = (crc_buffer[0] & 0xFF) | ((crc_buffer[1] & 0xFF) << 8);
    unsigned i, bit;

    for (i = 0; i < nbytes; ++i) {
	crc ^= data_buffer[i] & 0xFF;
	for (bit = 0; bit < 8; ++bit)
	    crc = crc & 1 ? (crc >> 1) ^ 0120001 : crc >> 1;
    }
    crc_buffer[1] = crc >> 8;
    crc_buffer[0] = crc;
}
-- 
Glenn Kasten
Ready Systems 470 Potrero Ave. Sunnyvale CA 94086 
glenn@ready.com (408) 522-7357 
-- 
Glenn Kasten
Ready Systems 470 Potrero Ave. Sunnyvale CA 94086 
glenn@ready.com (408) 522-7357