Subject: RE: miniSAS active cable keying
Date: Fri, 20 Jun 2008 11:54:37 -0400
From: "Gourgen Oganessyan" <gourgen@quellan.com>
To: <t10@t10.org>
X-Message-Number: 8874
Formatted message: HTML-formatted message

Alvin,
The idea was to prevent an active cable from plugging into a legacy
passive receptacle, because in such a scenario the link won't work, and
the group felt there needs to be keying to fool-proof this in the field.
On the other hand, a legacy passive cable can be plugged into a SAS 2.1
active receptacle, since that should work due to proposed sense pin and
power supply logic. The proposed reverse-gender keying accomplishes
that:
(Active plug with a key)  PLUGS INTO (Active Receptacle with a key-slot)
(Active plug with a key)  DOES NOT PLUG INTO (Passive Receptacle without
key-slots)
(Passive plug without a key)  PLUGS INTO (Active Receptacle with a
key-slot)
(Passive plug without a key)  PLUGS INTO (Passive Receptacle without
key-slots)
Gourgen Oganessyan
Quellan Inc.
Phone: (630)-802-0574 (cell)
Fax:	 (630)-364-5724
e-mail: gourgen@quellan.com <mailto:gourgen@quellan.com> 
________________________________
From: owner-t10@t10.org [mailto:owner-t10@t10.org] On Behalf Of
Alvin.Cox@seagate.com
Sent: Friday, June 20, 2008 10:04 AM
To: t10@t10.org
Subject: miniSAS active cable keying
During our last SAS phy conference call, there were separate keys
indicated for active cables (see 08-257r0
<http://www.t10.org/ftp/t10/document.08/08-257r0.pdf>; ). I am wondering
what the implementation plan is. The keys provide no protection from
plugging in a SAS 1.1 (legacy passive) cable and the phy's should work
with the SAS 2.0 10-meter passive version, so what is the advantage of
adding this key? I guess I am missing something in the planned
implementation. Could someone elaborate? 
Alvin Cox
Seagate Technology, LLC
Office 405-381-8067
Cell 405-206-4809
E-Mail	alvin.cox@seagate.com