[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [ethmac] CRC Magic number! How to figure out c704dd7b?




Hi,

   If you simple append without rotating and inverting you should always get
the value 0, this is actually the reason for the inverting rotating as the
concern was "stuck at zero" appear as good crc packet.

have a nice day

   Illan


-----Original Message-----
From: Jun Zhang [mailto:zhang_jun@tsinghua.org.cn]
Sent: Sunday, October 13, 2002 7:06 PM
To: ethmac@opencores.org
Subject: Re: [ethmac] CRC Magic number! How to figure out c704dd7b?


Hi:
         In my mind, Xillinx has such a application note about CRC.
         You may look for it in their web site. Also , you may find the file
         crc_v3.txt at ftp: ftp://ftp.rocksoft.com/papers/.
         I think it's really a good reference .
         Anyway, I have another question .  FCS data was transmitted in a
         order of D31,D30,D29 ....D1,D0. It's different from the transmit 
order of
         other fields of MAC frame. If just calculating the whole packet's 
CRC without
         changing the byte order of FCS field, can it get the result of 
c704dd7b?
         I really think it won't get the number. Anyone agree with me?

At 11:19 2002-10-11 -0100, you wrote:
>Dear All:
>I need the information or documentation about how to figure out the
>CRC magic number,c704dd7b.
>I've searched AMD Site that Allan said befor.
>However, I didn't get any documentation to reference.
>Could Allan or someone tell me that where I can get more information
>about CRC magic.
>I've searched Google, But still nothing at all.
>Therefore, I come here for helping.
>All I want to know is how to figure out it?
>Thanks!
>
>Have a nice day
>--
>To unsubscribe from ethmac mailing list please visit 
>http://www.opencores.org/mailinglists.shtml



---
Best regards.

Jun Zhang

Phone: 010-88354422-114
Mailto: zhangj99@mails.tsinghua.edu.cn



--
To unsubscribe from ethmac mailing list please visit
http://www.opencores.org/mailinglists.shtml
--
To unsubscribe from ethmac mailing list please visit http://www.opencores.org/mailinglists.shtml