SAS rate matching rules

Evans, Mark Mark_Evans at maxtor.com
Fri Apr 11 13:57:04 PDT 2003


* From the T10 Reflector (t10 at t10.org), posted by:
* "Evans, Mark" <Mark_Evans at maxtor.com>
*
Hello all,

I think we've identified that SAS r3f isn't complete in specifying the rules
for when to start rate matching.  The following are some bits that could be
changed to rectify this.  I don't think this changes any intent, it's just
an attemp to make sure that everything is spelled out.  So, I recommend that
something like the following three minor changes be included in the next rev
of the SAS draft standard as an editorial update.


1) Change the fifth paragraph in 7.13 Rate matching (the paragraph
immediately after Figure 84 - Rate matching example) from:

"The source phy shall start inserting ALIGNs and NOTIFYs for rate matching
at the selected connection rate with the first dword following the EOAF for
the OPEN address frame. The source phy transmits idle dwords including
ALIGNs and NOTIFYs at the selected connection rate while waiting for the
connection response.  This enables each expander device to start forwarding
dwords from the source phy to the destination phy after forwarding an
OPEN_ACCEPT."

to:

"The source phy shall start inserting ALIGNs and NOTIFYs for rate matching
at the selected connection rate with the first dword following:

a) the EOAF for an OPEN address frame; and
b) an OPEN_ACCEPT sent in response to an OPEN address frame.

The source phy transmits idle dwords including ALIGNs and NOTIFYs at the
selected connection rate while waiting for the connection response.  This
enables each expander device to start forwarding dwords from the source phy
to the destination phy after forwarding an OPEN_ACCEPT."


2) Change the sixth paragraph in 7.13 Rate matching from:

"A phy shall stop inserting ALIGNs and NOTIFYs for rate matching after
transmitting the first dword in a CLOSE."

to:

"A source phy shall stop inserting ALIGNs and NOTIFYs for rate matching
after:

a) transmitting the first dword in a CLOSE;
b) transmitting the first dword in a BREAK;
c) receiving of an OPEN_REJECT ending a connection attempt; and
d) losing arbitration to a received OPEN."


3) Change the first sentence in 7.14.4.5.1 [SL_CC3:Connected state] State
description from:

"This state enables the SSP, STP, or SMP link layer state machine to
transmit dwords during a connection."

to:

"This state enables the SSP, STP, or SMP link layer state machine to
transmit dwords during a connection (see 7.13 for rules on rate matching)."


Please feel free to contact me with any questions that you may have about
this.

Regards,

Mark Evans
Maxtor Corporation
*
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at t10.org




More information about the T10 mailing list