CRC calculation

[ALuPin]

Hi,

I have found a piece of C code for checksum calculation
CRC16 ccitt.

Is that right?
How can I initialize crc?


#include <stdio.h>

int crc_1021(int data)
{

int x;

x = ((crc>>8) ^ data) & 0xff;
x ^= x>>4;
crc = (crc << 8) ^ (x << 12) ^ (x <<5) ^ x;
crc &= 0xffff;

return(crc);

}

int main()

{
int crc
printf("The CRC16-X25_ccitt of %d is %d. \n", crc, crc_1021(crc));
return 0;
}

[Grumble]

ALuPin wrote:

I have found a piece of C code for checksum calculation
CRC16 ccitt.

Is that right?
How can I initialize crc?

Errr. Where is your question about the C language?

[Jack Klein]

On 2 Jul 2004 04:23:19 -0700, AL****@web.de (ALuPin) wrote in
comp.lang.c:

Hi,

I have found a piece of C code for checksum calculation
CRC16 ccitt.

Is that right?
How can I initialize crc?


#include <stdio.h>

int crc_1021(int data)
{

int x;

x = ((crc>>8) ^ data) & 0xff;
x ^= x>>4;
crc = (crc << 8) ^ (x << 12) ^ (x <<5) ^ x;
crc &= 0xffff;

return(crc);

}

int main()

{
int crc
Change the line above to:

int crc = /* whatever initial value you want */
printf("The CRC16-X25_ccitt of %d is %d. \n", crc, crc_1021(crc));
return 0;
}

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
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alt.comp.lang.learn.c-c++
http://www.contrib.andrew.cmu.edu/~a...FAQ-acllc.html

[ALuPin]

Grumble <a@b.c> wrote in message news:<cc**********@news-rocq.inria.fr>...

ALuPin wrote:

I have found a piece of C code for checksum calculation
CRC16 ccitt.

Is that right?
How can I initialize crc?

Errr. Where is your question about the C language?

Hey,

if you do not want to help then SHUT UP.

Thank you very much.

Best regards

[xarax]

"ALuPin" <AL****@web.de> wrote in message
news:b8**************************@posting.google.c om...

Grumble <a@b.c> wrote in message news:<cc**********@news-rocq.inria.fr>...

ALuPin wrote:

I have found a piece of C code for checksum calculation
CRC16 ccitt.

Is that right?
How can I initialize crc?

Errr. Where is your question about the C language?

Hey,

if you do not want to help then SHUT UP.

Thank you very much.

Best regards

You are posting your question in the wrong
group, so please take your own advice.

[Mark McIntyre]

On 5 Jul 2004 00:07:31 -0700, in comp.lang.c , AL****@web.de (ALuPin)
wrote:

Grumble <a@b.c> wrote in message news:<cc**********@news-rocq.inria.fr>...

Errr. Where is your question about the C language?

if you do not want to help then SHUT UP.

You ask an offtopic question, get asked what your actual relevant question
is, and are rude? Thats very silly.
Thank you very much.

Welcome.
--
Mark McIntyre
CLC FAQ <http://www.eskimo.com/~scs/C-faq/top.html>
CLC readme: <http://www.angelfire.com/ms3/bchambless0/welcome_to_clc.html>
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