Additional correction in SAS2r15a for second public review
Elliott, Robert (Server Storage)
Elliott at hp.com
Mon Mar 16 22:07:00 PDT 2009
* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert (Server Storage)" <Elliott at hp.com>
I agree. It looks like 02-300r2.pdf was correctily incorporated into
sas-r01c in September 2002 with SNTT in the description, but this letter
ballot comment from LSI on sas-r03 was accepted in November 2002 to change it
ACCEPT - DONE (no note)
22.214.171.124.3 Transition SP11:SAS_AwaitALIGN1 to SP14:SAS_ AwaitSNW
Replace "SNTT" with "SNLT".
Should we add a note to clarify that this transition is not taken if ALIGN1
is detected after SNLT expires and before SNTT expires?
The intent is the transmitter must transmit ALIGN (1) within SNLT and the
receiver must allow the full SNTT to see it, allowing for (SNTT - SNLT)
uncertainty in the time that the SNW begins.
From: Bill.Martin at Emulex.Com [mailto:Bill.Martin at Emulex.Com]
Sent: Monday, March 16, 2009 6:43 PM
To: Elliott, Robert (Server Storage); t10 at t10.org
Subject: Additional correction in SAS2r15a for second public review
Rob & T10:
At the SAS protocol meeting today, it was discovered that in the SP11 state
there is an error in 126.96.36.199.3.
In 188.8.131.52.2 where the protocol for speed negotiation windows is defined
there are the following two statements:
In Figure 154 it states -
If the phy's receiver achieves dword synchronization at the SNW rate within
SNLT, its transmitter transmits ALIGN (1)s at the SNW rate for the remainder
of the SNTT.
After table 99 it states -
If the phy supports the SNW, then after RCDT it shall attempt to attain dword
synchronization on an incoming series of dwords (e.g., ALIGN (0) or ALIGN (1)
primitives) at that rate for the SNLT:
a) if the phy achieves dword synchronization within
the SNLT, then it shall change from transmitting ALIGN (0) primitives to
transmitting ALIGN (1) primitives for the remainder of the SNTT (i.e., the
remainder of the SNW time). The point at which the phy achieves dword
synchronization is called the actual lock time (ALT); or
b) if the phy does not achieve dword synchronization
within the SNLT, then it shall continue transmitting ALIGN (0) primitives for
the remainder of the SNTT (i.e., the remainder of the SNW time).
At the end of the SNTT:
a) if the phy is both transmitting and receiving
ALIGN (1) primitives, then it shall consider the SNW to be valid; or
b) if the phy is not both transmitting and receiving
ALIGN (1) primitives, then it shall consider the SNW to be invalid. The phy
shall disable SSC (see 5.7.6) during SNW-1, SNW-2, and Final-SNW.
The first list is describing state SP10 and item a) is the transition from
SP10 to SP11. The second list is describing SP11 and item a) is the
transition from SP11 to SP12. The issue is that the transition from SP11 to
SP12 is taken "if phy is both transmitting and receiving ALIGN (1)
primitives" by the end of SNTT; however 184.108.40.206.3 states:
220.127.116.11.3 Transition SP11:SAS_AwaitALIGN1 to SP12:SAS_AwaitSNW
This transition shall occur if this state receives an ALIGN Received (1)
message before the SNLT timer expires. This indicates that the attached phy
has been able to achieve dword synchronization in the current SNW.
This transition is based on receiving the ALIGN Received (1) message before
the SNLT timer expires not the SNTT timer. It was agreed by those present at
the SAS protocol working group meeting today that this should be changed to
SNTT in the version of SAS-2 that is published for public review.
Office of Technology
916 765-6875 (Cell)
bill.martin at emulex.com
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