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Message
From: "kw@nie" <kwanie@p...>
Date: Thu, 21 Feb 2002 00:36:52 +0800
Subject: RE: [usb] crc algorithm
I think I know why the binary representations, in the USB specification, are
different from the polynomials. Attached is a brief explanation based on the
5-bit CRC but the principle applies for both CRC generators.
Cheers,
kwanie
-----Original Message-----
From: owner-usb@o... [mailto:owner-usb@o...] On Behalf
Of kebloo@m...
Sent: 21 February 2002 08:34
To: usb@o...
Subject: [usb] crc algorithm
Hello,
Sorry for this beginner question, but I wish some one could
answer my curiosity...
USB 1.1 specification defines generator polynomial of 5-bit crc
as G(x) = x^5+x^2+1 and binary pattern that represent it as
00101B and 16-bit crc as G(x) = x^16+x^15+x^2+1 and
binary pattern that represent it as 1000000000000101B.
My question is why the binary pattern stated like that and
not 100101B for 5-bit crc and 11000000000000101B ?
Thanks....
Best Regard,
RE Tambunan
crc5.JPG
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