To: t10@t10.org Subject: Reminder: SAS PHY WG call, 11/16, 10 am CST From: Alvin.Cox@seagate.com Date: Tue, 14 Nov 2006 09:51:04 -0600 X-Message-Number: 7381 Formatted message: HTML-formatted message Weekly teleconferences scheduled for Thursdays at 10 am CST: PARTICIPANT INFORMATION: Toll Free Dial in Number: (866) 279-4742 International Access/Caller Paid Dial In Number: (309) 229-0118 PARTICIPANT CODE: 3243413 Webex information: https://seagate.webex.com/seagate Topic: SAS-2 PHY WG Date: Thursday Time: 10:00 am, Central Standard Time Meeting number: 826 515 680 Meeting password: 6gbpsSAS No call on 11/23 or 12/28. Agenda (more than we can cover): 1. SAS-2 Modifications to the SAS Speed Negotiation 06-324r9 [Finch, Wassal] http://www.t10.org/ftp/t10/document.06/06-324r9.pdf (Should be a final review of the edited version.) 2. SAS-2 Electrical Specification Proposal 06-496 [Witt] http://www.t10.org/ftp/t10/document.06/06-496r2.pdf Page 13 has some interesting questions: (I would like to concentrate on c and e this call.) a) SSC Causes Measurement Issues: • Tx Jitter Generation • Rx Jitter Tolerance b) Tx De-Emphasis Causes DJ Which Needs to be Removed Before Jitter Generation Can Be Estimated? c) Question: Do we Want to Support a Low-Swing Mode for Short / Clean Channels? Just refer to use SATA 2 level for power saving if desired. • 400..600mV • No De-Emphasis (My comment on this is that it is intended for IC-to-IC on a single PCB and does not use an existing defined compliance point. The specification allows deviation if the connection is not a compliance point, so my initial position is that we don't want to do this.) d) Are We Going to Define a Rx Compliance Channel / Test? Yes we need to. e) Are we going to support variable or fixed Tx De-Emphasis? My comments: • If fixed, how do we test? • The table on page 6 has a -5dB to -7dB range for de-emphasis, but has a differential voltage range of 800 min / 1200 max. These seem to be in conflict. • Mike Jenkins has presented simulations that indicate a fixed de-emphasis may not be in the best interest. http://www.t10.org/ftp/t10/document.06/06-491r1.pdf What do we do? Maybe we allow de-emphasis to be used, but bounded by the allowed transmitter differential voltage values? • Is the external cable application different than the internal requirements with regards to de-emphasis requirements? 3. 10-meter cable specification issues http://www.t10.org/ftp/t10/document.06/06-499r0.pdf Any updates? 4. EMI considerations for SAS-2 http://www.t10.org/ftp/t10/document.06/06-483r0.pdf Keep in mind when developing spec. 5. Define a loss for the zero-length test load? Alvin Cox Seagate Technology, LLC Tel 405-350-7424 Cell 405-206-4809 E-Mail alvin.cox@seagate.com