SAS 2 - scrambler operation

Stephen FINCH steve.finch at
Thu Jul 19 15:52:49 PDT 2007

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During discussions of Training and the use/definition of Training patterns,
the subject of when to reset the scrambler was explicitly addressed.  The
text of the proposed standard clearly states it is reset at the end of RCDT
in a Train-SNW and not reset again during that Train-SNW.  So the text in
the proposed standard wasn't just an arbitrary statement but one with
One may always make a proposal, but I don't see a need to change and others
my have stronger feelings. 
Steve Finch
From: owner-t10 at [mailto:owner-t10 at] On Behalf Of
Andrew.Roy at
Sent: Thursday, July 19, 2007 2:43 PM
To: David Freeman
Cc: owner-t10 at; Robert Watson; t10 at
Subject: RE: SAS 2 - scrambler operation
Your proposal makes me unhappy for one reason:	it is conceivable that 
somebody's receiver design will depend on receiving a certain bit pattern 
in order to train itself.  Therefore, I think it's important to have all the
out there doing the same thing. 
Andy Roy 
PS: Just my own opinion, not an official position of LeCroy. 
Thank you for your reply. 
I agree that it is important to keep with the rest of the standard. 
Section 7.4 defines the idle dwords that are sent when a link is idle. 
"Idle dwords are vendor-specific data dwords which are scrambled (see 7.6)."
It would seem to me that a precedents has been set for allowing
"vendor-specific" implementation of the "scrambled training data" dwords
between the train primitives. 
if this is agreeable with the parties concerned I would be willing to draft
a proposal. 
David Freeman 
Finisar Corp 

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