SAS2 Speed Negotiation 06-515 switching between patterns

Day, Brian Brian.Day at
Tue Nov 21 11:21:56 PST 2006

* From the T10 Reflector (t10 at, posted by:
* "Day, Brian" <Brian.Day at>
So as I interpret this (which is the point of my question), it would be
okay to truncate the both the TRAIN pattern and TRAIN_DONE when
switching to a new pattern due to the state machine changing at
arbitrary points in time.
For example, if SP state is currently in SP29:SAS_Train state and
transmitting the TRAIN pattern, when the conditions to transition to
SP30:SAS_TrainingDone occur at an arbitrary point in time, the SP
transmitter would then switch to sending TRAIN_DONE patterns.  
In other words, there may be less than 58 dwords of random scrambled
data between the TRAIN and TRAIN_DONE primitive sequences.
Actually, there might not be anything preventing the TRAIN primitive
itself from being less than 6 dwords when making this transition... I'm
not sure on this one to be honest.
Same reasoning applies when going from the TrainingDone to PHY_Ready
Is there objection to this type of allowed behavior?  Would that
behavior be okay for the receiver that is still training without messing
up the training algorithm?
I feel this should be allowed behavior from a digital state machine
design standpoint, as it keeps it simple... the actual implementation of
the SP state machine does need to know about the specific dword "state"
of the training pattern.  
Brian Day
LSI Logic
-----Original Message-----
From: owner-t10 at [mailto:owner-t10 at] On Behalf Of Stephen
Sent: Friday, November 17, 2006 8:54 AM
To: T10 Reflector
Subject: SAS2: Speed Negotiation proposal 06-515r0 (formerly 06-423r9)
now available
* From the T10 Reflector (t10 at, posted by:
* Stephen FINCH <steve.finch at>
Following the review during the SAS2 Phy conference call yesterday,
editorial updates have been made to 06-324.  We ran out of revision
numbers, so a new document number has been generated.
It is my belief that we now have the SAS2 speed negotiation process well
defined.  I plan to move to include this information into the SAS2 draft
at the January meetings, so take the time now to review this material.
Steve Finch
303 381-3587
Steve.finch at
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