SAS 2 - bit ordering for SNW-3 settings

Sheffield, Robert L robert.l.sheffield at
Thu Mar 22 11:17:12 PDT 2007

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Intel has assumed the opposite.
Question - is the bit numbering in table-84 correct? In every other
instance where bits in a field are transmitted across the wire, the
first bit transmitted is the highest numbered bit in the field and is
the highest order. Why is the start bit numbered "0" and not "31"? I
think there's a 100% chance that breaking convention here will result in
non-interoperable solutions.
From: owner-t10 at [mailto:owner-t10 at] On Behalf Of Day,
Sent: Wednesday, March 21, 2007 1:39 PM
To: T10 Reflector
Subject: SAS 2 - bit ordering for SNW-3 settings
Any opinions to the contrary?
From: Elliott, Robert (Server Storage) [mailto:Elliott at] 
Sent: Wednesday, March 21, 2007 12:10 PM
To: Day, Brian
Cc: Stephen FINCH; Tim Symons; Amr Wassal; Alvin.Cox at
Subject: RE: bit ordering for SNW-3 settings
Good question.
Based on the bit layout proposed in 07-091 for the SMP functions, I
think bit 4 should be the MSB and bit 7 should be the LSB.  That way, in
the SMP functions, it will have its natural encoding.
I suggest you post this Q&A to the T10 reflector to make sure nobody
else has assumed the opposite.
Rob Elliott, elliott at 
Hewlett-Packard Industry Standard Server Storage Advanced Technology 
	From: Day, Brian [mailto:Brian.Day at] 
	Sent: Wednesday, March 21, 2007 11:55 AM
	To: Elliott, Robert (Server Storage)
	Subject: bit ordering for SNW-3 settings
	Can you clarify for me the bit ordering for the REQUESTED
LOGICAL LINK RATE in the SNW-3 settings? 
	The example uses "9", which is the same bit flipped or not. 
	Would be great to get a 1.5 example added to spec too since that
would show correct bit positions. 
	Brian Day 
	LSI Logic 
	(719) 533-7468 

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