Draft Minutes of Parallel SCSI WG - May 16, 2000

John Lohmeyer lohmeyer at t10.org
Tue May 23 12:01:58 PDT 2000


* From the T10 Reflector (t10 at t10.org), posted by:
* John Lohmeyer <lohmeyer at t10.org>
*
A PDF version of these minutes is available at:

    ftp://ftp.t10.org/t10/document.00/00-205r0.pdf

Accredited Standards Committee*
National Committee for Information Technology Standards (NCITS)

                                                     Doc. No.: T10/00-205r0
                                                         Date: May 23, 2000
                                                     Reply to: John Lohmeyer

To:       T10 Membership
From:     Ralph Weber & John Lohmeyer
Subject:  Parallel SCSI Working Group Meeting -- May 16, 2000
           Nashua, NH


Agenda

1.  Opening Remarks
2.  Approval of Agenda
3.  Attendance and Membership
4.  SPI-4 Initial Review of Pre-Revision 0 [Penokie]
5.  SPI-4 Physical Topics
5.1   Free Running Clock
5.1.1     SPI-4 clocking proposal (99-262) [Petty]
5.2   Training Patterns
5.2.1     Ultra320 SCSI Calibration Protocol (00-133) [Leshay]
5.2.2     Proposal for training pattern to be included in SPI-4 (00-132)
[Evans]
5.2.3     Proposed Training for Skew Compensation (00-174) [Bastiani]
5.2.4     Training pattern DC signal strengths (00-231r0) [Elliott]
5.2.5     Training Performance (00-236) [Brown]
5.2.6     Precompensation plus equalization (00-225r1) [Uber]
5.3   Timings
5.4   Test Configurations
5.4.1     Requirements for Measuring Receive Signals in SPI-4 and beyond
(00-149) [Ham]
5.4.2     Receiver Input Voltage Budget for Eye Patterns (00-158)
[Bridgewater]
5.4.3     Specifying signals at receiver using receiver equalization (00-223)
[Uber]
5.4.4     Precompensation and test measurements (00-194) [Manildi]
5.4.5     Cable Attenuation (00-235r0) [Uber]
5.5   Other SPI-4 Physical Topics
5.5.1     Expander Topics (00-199) [Ham]
5.5.2     The zero offset problem for receiver equalization (00-201)
[Bridgewater]
5.5.3     Should QAS be obsoleted in SPI-4? (00-228) [Elliott]
5.5.4     SPIP Report (Ham)
5.6   Protocol
5.6.1     Remove Data Groups from Fast-160 [Penokie]
5.6.2     Flow Control & Read Streaming (00-142) [Lamers]
5.6.3     PPR Message Enhancements (99-283) [Lamers]
5.7   Receiver Issues
5.7.1     Receiver Specifications [Ham]
5.7.2     Calculated Signal Losses (00-227) [Aloisi]
6.  Expanders and Domain Validation Topics
6.1   SCSI out of band communications method (99-213) [Petty]
7.  New Business
8.  Meeting Schedule
9.  Adjournment


Results of Meeting

1.  Opening Remarks

John Lohmeyer, the T10 Chair, called the meeting to order at 9:00 a.m.,
Tuesday May 16, 2000.  He thanked Zane Daggett of Hitachi Cable Manchester for
hosting the meeting.

As is customary, the people attending introduced themselves and a copy of the
attendance list was circulated.


2.  Approval of Agenda

The draft agenda was approved with the following additions and changes:

4.  SPI-4 Initial Review of Pre-Revision 0 [Penokie]
5.2.4     Training pattern DC signal strengths (00-231) [Elliott]
5.2.5     Training Performance (00-236) [Brown]
5.2.6     Precompensation plus equalization (00-225r1) [Uber]
5.4.5     Cable Attenuation (00-235r0) [Uber]

During the course of the meeting, the following agenda items were
added/revised:

5.5.4     SPIP Report (Ham)
5.6.3     PPR Message Enhancements (99-283) [Lamers]


3.  Attendance and Membership

Attendance at working group meetings does not count toward minimum attendance
requirements for T10 membership.  Working group meetings are open to any
person or organization directly and materially affected by T10's scope of
work.  The following people attended the meeting:

          Name          S        Organization         Electronic Mail Address
---------------------- -- ------------------------- -------------------------
Mr. Lawrence J. Lamers P  Adaptec, Inc.             ljlamers at ieee.org
Mr. Vincent Bastiani   V  Adaptec, Inc.             bastiani at corp.adaptec.com
Mr. Charles Brill      P  AMP / Tyco Electronics    cebrill at ix.netcom.com
Mr. Douglas Wagner     P  Berg Electronics          wagnerdl at bergelect.com
Mr. Bill Galloway      P  BREA Technologies, Inc.   billg at breatech.com
Mr. Suren Shah         V  C&M Corp.                 rgannon at cm-corp.com
Mr. Edward Haske       P  CMD Technology            haske at cmd.com
Mr. Robert C. Elliott  P  Compaq Computer Corp.     Rob_Elliott at compuserve.
                                                     com
Dr. William Ham        A  Compaq Computer Corp.     bill.ham at digital.com
Mr. Neil Wanamaker     P  Crossroads Systems, Inc.  ntw20 at netcom.com
Mr. John Tyndall       A  Crossroads Systems, Inc.  jtyndall at crossroads.com
Mr. I. Dal Allan       P  ENDL                      endlcom at acm.org
Mr. Ralph O. Weber     A  ENDL Texas                roweber at acm.org
Mr. Eugene Lew         P  Fujitsu                   elew at fcpa.fujitsu.com
Mr. Zane Daggett       P  Hitachi Cable Manchester, zdaggett at hcm.hitachi.com
                           Inc
Mr. John Lohmeyer      P  LSI Logic Corp.           lohmeyer at t10.org
Mr. Andrew Brown       V  LSI Logic Corp.           andrew.brown at lsil.com
Mr. Mark Strauss       V  Lucent Technologies       msstrauss at lucent.com
Ms. Jie Fan            P  Madison Cable Corp.       jfan at madisoncable.com
Mr. Jay Neer           P  Molex Inc.                jneer at molex.com
Mr. Edward A. Gardner  P  Ophidian Designs          eag at ophidian.com
Mr. Skip Jones         P  QLogic Corp.              sk_jones at qlc.com
Mr. Richard Moore      A# QLogic Corp.              r_moore at qlc.com
Mr. Richard L.         V  QLogic Corp.              r_romaniec at qlc.com
Romaniec
Mr. Mark Evans         P  Quantum Corp.             mark.evans at quantum.com
Mr. Bruce Leshay       V  Quantum Corp.             bleshay at tdh.qntm.com
Mr. Richard Uber       V  Quantum Corp.             duber at tdh.qntm.com
Mr. Gene Milligan      P  Seagate Technology        Gene_Milligan at notes.
                                                     seagate.com
Mr. Gerald Houlder     A  Seagate Technology        gerry_houlder at notes.
                                                     seagate.com
Mr. Daniel (Dan) F.    O  Seagate Technology        daniel_f_smith at notes.
Smith                                               seagate.com
Mr. A. Bruce Manildi   V  Seagate Technology        bruce_manildi at notes.
                                                     seagate.com
Mr. Mayank R. Patel    V  Seagate Technology        mayank_r_patel at notes.
                                                     seagate.com
Mr. John Masiewicz     V  Seagate Technology        john_masiewicz at notes.
                                                     seagate.com
Mr. Erich Oetting      P  Storage Technology Corp.  erich_oetting at stortek.com
Mr. Kenneth Moe        P  Sun Microsystems, Inc.    kenneth.moe at sun.com
Mr. Paul D. Aloisi     P  Texas Instruments         Paul_Aloisi at ti.com
Mr. Donald R. Getty    A# Texas Instruments         donald_getty at ti.com

37 People Present

Status Key:  P    -  Principal
              A,A# -  Alternate
              O    -  Observer
              L    -  Liaison
              V    -  Visitor


4.  SPI-4 Initial Review of Pre-Revision 0 [Penokie]

George Penokie projected a pre-revision 0 SPI-4 document.  He explained that
he had to make wording changes from the proposals recommended by the working
group in developing the document.  As an example, he noted that `training' has
been changed to `pacing' in many places.  Because of that, he asked the group
to review revision 0 of SPI-4 carefully.

The group requested many changes in the draft text and George took notes
regarding corrections.  George said he expects to have revision 0 prepared for
the next mailing.


5.  SPI-4 Physical Topics

5.1 Free Running Clock

5.1.1 SPI-4 clocking proposal (99-262) [Petty]

Andy Brown asked that discussion of this topic be deferred to a subsequent
meeting.

5.2 Training Patterns

5.2.1 Ultra320 SCSI Calibration Protocol (00-133) [Leshay]

Bruce Leshay asked that this topic be removed from this and future agendas.

5.2.2 Proposal for training pattern to be included in SPI-4 (00-132) [Evans]

Mark Evans asked that this topic be removed from this and future agendas.

5.2.3 Proposed Training for Skew Compensation (00-174) [Bastiani]

Vince Bastiani asked that this topic be removed from this and future agendas.

5.2.4 Training pattern DC signal strengths (00-231r0) [Elliott]

Rob Elliott questioned the use of precompensation during training.  He
expressed the belief that disabling precompensation during the training might
be helpful to receiver AAF (adjustable active filter).  However, this belief
was questioned.  Rob moved that 00-231r0 be recommended for inclusion in
SPI-4.  Mark Evans seconded the motion.  The motion passed on a vote of 7:2:9.

5.2.5 Training Performance (00-236) [Brown]

Andy Brown presented theoretical data (00-236r0) showing the adverse impact of
not doing QAS (quick arbitrate and select) and of training on each connection.
George Penokie presented similar data (00-237r0) but preferred that training
be retained on each connection and that QAS also be retained. After the
presentations were completed, the question on the floor was making QAS
obsolete (see item 5.5.3).

The group also considered changing when training is performed.  John Lohmeyer
moved that the only time training is performed is immediately following a PPR
and that the training results be remembered after that.  Bill Galloway
seconded the motion.  After discussing the motion, John withdrew the motion,
stating that he needed to discuss the frequency of training with the LSI
engineers.

5.2.6 Precompensation plus equalization (00-225r1) [Uber]

Dick Uber presented new data and eye diagrams showing the relationship between
precompensation and receiver AAF (adjustable active filter).  He noted that
hold time issues dominate the eye diagram openings when the AAF boost is
forced to values of 1.6 and 2.0.  He concluded by showing that the best eye
diagrams are obtained by disabling precompensation and having an AAF with a
boost of 2.0.

5.3 Timings

No SPI-4 timing topics were brought before this meeting.

5.4 Test Configurations

5.4.1 Requirements for Measuring Receive Signals in SPI-4 and beyond (00-149)
[Ham]

Bill Ham asked that this topic be deferred to a subsequent meeting.

5.4.2 Receiver Input Voltage Budget for Eye Patterns (00-158) [Bridgewater]

Vince Bastiani asked that this item be deferred to a subsequent meeting.

5.4.3 Specifying signals at receiver using receiver equalization (00-223)
[Uber]

Dick Uber asked that this topic be deferred to a subsequent meeting.

5.4.4 Precompensation and test measurements (00-194) [Manildi]

John Masiewiez asked that this topic be deferred to a subsequent meeting.

5.4.5 Cable Attenuation (00-235r0) [Uber]

Dick Uber presented laboratory data on cable attenuation as related to SPI-4.

5.5 Other SPI-4 Physical Topics

5.5.1 Expander Topics (00-199) [Ham]

Bill Ham presented the latest revisions in 00-199r1.  The group discussed how
the content of 00-199r1 would be incorporated in SPI-4.  Bill Ham moved that
the technical contents of 00-199r2 (r1 as modified) be incorporated as
normative additions to SPI-4.  Gene Milligan seconded the motion.  The group
requested changes in the proposal and Bill agreed.  The motion passed on a
vote of 9:0:2.

5.5.2 The zero offset problem for receiver equalization (00-201) [Bridgewater]

Vince Bastiani asked that this topic be deferred to a subsequent meeting.

5.5.3 Should QAS be obsoleted in SPI-4? (00-228) [Elliott]

Based on the discussion in item 5.2.5, Rob Elliott asked the group to consider
making QAS obsolete in SPI-4.  He presented several reasons for making QAS
obsolete (00-228).  Rob Elliott moved that 00-228 be recommended for inclusion
in SPI-4.  Bill Galloway seconded the motion.  The motion failed on a vote of
1:6:12.

5.5.4 SPIP Report (Ham)

Bill Ham reported on the activities SPIP (SCSI Passive Interconnect
Performance) study group (minutes in 00-217).  He emphasized the goals of the
Technical Report that the group plans to propose as a new T10 project (see
section 11 of the minutes in 00-217r0).

5.6 Protocol

5.6.1 Remove Data Groups from Fast-160 [Penokie]

George Penokie moved that the group recommend that data group transfers be
prohibited from use with paced data transfers.  Bill Galloway seconded motion.
The motion passed on a vote of 7:3:9.

5.6.2 Flow Control & Read Streaming (00-142) [Lamers]

Larry Lamers reviewed changes in 00-142r3.  The group requested some changes
in the names of things in the proposal and Larry agreed.  Larry Lamers moved
that 00-142r4 (r3 as amended) be recommended for inclusion in SPI-4.  Gene
Milligan seconded the motion.  Further wording changes were requested and
agreed by Larry.  The motion passed on a vote 9:1:6.

5.6.3 PPR Message Enhancements (99-283) [Lamers]

Larry Lamers presented a proposal to make several transfer period code values
obsolete in SPI-4.  Concerns were raised about the need for making the change
and the response was that it simplifies aspects of SPI-4.  A straw poll
recommended no specific action on a vote of 4:4:8.  Larry asked that this
topic be removed from future agendas.

5.7 Receiver Issues

5.7.1 Receiver Specifications [Ham]

Bill Ham asked the group to consider how SPI-4 should specify receiver
bandwidth and reviewed the basic issues of the problem.  Bill asked that
discussion of this topic be deferred to the next meeting, noting that this is
a critical issue that needs closure.

5.7.2 Calculated Signal Losses (00-227) [Aloisi]

Paul Aloisi presented a calculated signal loss spreadsheet (00-227r1).  Paul
recommended changes in the percentage differences between the strong and weak
drive requirements.  Paul moved to recommend that the weak driver level range
be changed to 60% - 75% (as opposed to the current 60% - 85%).  George Penokie
seconded the motion.  John Masiewiez offered a friendly amendment to change to
60% - 78%, which Paul and George accepted.  The amended motion passed on a
vote of 8:1:3.

Paul also had concerns about the receiver mask.  John Masiewiez expressed
concerns that more study is required before making changes in this area.
Better cables were offered as an alternative to changing the receiver mask,
however, others felt that the cable has little to offer as a solution for the
problems identified by Paul.  George Penokie opened the SPI-4 revision 0
document and the group worked through where TBD had to be entered in place of
values to avoid publishing values that are open to potential change.  Paul
Aloisi moved that until we have numbers add up to the worst case tolerancing
the working group recommend T10 use TBD in SPI-4 revision 0 in the receiver
threshold, driver asymmetry, and minimum drive level.  George Penokie seconded
the motion.   The motion passed on a vote of 8:2:0.


6.  Expanders and Domain Validation Topics

6.1 SCSI out of band communications method (99-213) [Petty]

John Lohmeyer asked that this topic be deferred to a subsequent meeting.


7.  New Business

No new business was brought before this meeting.

8.  Meeting Schedule

The next meeting of the Parallel SCSI Working Group will be Tuesday July 11,
2000 commencing at 9:00 a.m.  in Colorado Springs, CO.  NOTE: The group
elected to NOT meet in Lisle, IL June 15-16.

9.  Adjournment

The meeting was adjourned at 7:25 p.m. on Tuesday, May 16, 2000.


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