Reminder: SAS PHY teleconference, 10am CDT, July 20,2006
Alvin.Cox at seagate.com
Alvin.Cox at seagate.com
Mon Jul 17 15:26:40 PDT 2006
Formatted message: <A HREF="r0607174_f.htm">HTML-formatted message</A>
Next conference call July 20, 2006
Toll Free Dial in Number: (866) 279-4742
International Access/Caller Paid Dial In Number: (309) 229-0118
PARTICIPANT CODE: 3243413
Topic: SAS-2 PHY WG
Date: Thursday, July 20, 2006
Time: 10:00 am, Central Daylight Time (GMT -05:00, Chicago)
Meeting number: 826 515 680
Meeting password: 6gbpsSAS
Agenda: Speed negotiation sequence
During the face-to-ace meeting in Colorado Springs, a new proposal for the
G3 window was introduced that uses an out of band communication to
broadcast PHY capabilities. This method preserves the existing speed
negotiation window structure without depending on G1 or G2 capability to
work in future generations. I have provided a preliminary list of
considerations concerning 05-397r5 in the meeting minutes and have
included them below. There has also been a proposal posted on the T10 site
concerning how the out of band data could be configured. We will discuss
these proposals and concerns during the call (limited to approximately 2
Uses OOB at 1.5Gbps with a 9uS idle and a 10uS initial burst to "start the
clock". The 59 10uS intervals start from the far end of the 609uS standard
window. Later this was changed to a 10us idle at the end and 58 intervals
Since OOB already requires the 1.5Gbps bursts, this proposal has a subset
of the existing OOB requirement and is actually less demanding because of
the relatively long signal bursts.
This OOB section has been moved to the existing G3 window following the G2
window rather than having âG2 supporting SSCâ in the G3 slot. After this
G3 window, the final speed negotiation window is entered at the highest
common feature set enabled.
One suggestion was to make the intervals a binary code with a table to
decode what it means.
Present method uses the particular time area as positive indication of
support if active signal.
The intervals may need to include an idle time if the squelch detector is
used, as a discharge time may be required to accurately detect the
presence of signal.
Failure of the final speed negotiation window shall be handled by a
higher-level layer (not the PHY).
If there was a failure at the highest negotiated speed and the
initiator/expander changed the supported options, then how would it reset
to full capability if the device was changed?
A concern was raised that using the scrambler in the training sequence may
involve the link layer.
Since the last interval in the configuration window is idle, the training
data may start at the beginning of the final speed negotiation window, but
shall start by the end of a defined RCDT (not necessarily the same length
of time as the previous RCDTâs). Input is needed on how long this RCDT
How is the final speed negotiation window completed? Should there be
ALIGN0/ALIGN1 after TRAINdone is exchanged to verify dword sync?
SAS-2 Start-up training sequence (05-397) [Newman]
Proposal New Speed Negotiation for SAS-2 (06-354) [Finch]
Seagate Technology, LLC
E-Mail alvin.cox at seagate.com
More information about the T10