Draft Minutes of SPI-3 Working Group - May 22, 1998

John Lohmeyer lohmeyer at ix.netcom.com
Fri May 22 19:14:12 PDT 1998

* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* John Lohmeyer <lohmeyer at ix.netcom.com>
Accredited Standards Committee*
National Committee for Information Technology Standards (NCITS)

                                                      Doc. No.: T10/98-179r0
                                                          Date: May 22, 1998
                                                      Reply to: John Lohmeyer

To:      T10 Membership
From:    John Lohmeyer
Subject: SPI-3 Working Group Meeting -- May 22, 1998
         Chicago, IL


1. Opening Remarks
2. Approval of Agenda
3. Attendance and Membership
4. SPI-3 Topics
4.1 Phase Naming
4.2 CRC Proposals
4.3 Learn Mode (Domain Validation)
4.4 Expander Communication
4.5 QAS
4.6 Parallel Protocol Request Negotiation
4.7 Fast-80
5. Meeting Schedule
6. Adjournment

Results of Meeting

1.   Opening Remarks

John Lohmeyer, the T10 Chair, called the meeting to order at 9:00 a.m., Monday
May 22, 1998.  He thanked Gene Milligan of Seagate for hosting the meeting and
providing lunch.

As is customary, the people attending introduced themselves and a copy of the
attendance list was circulated.  John noted that standards are not permitted
to contain known patented material unless the patent holder agrees to comply
with the ANSI patent policy.

2.   Approval of Agenda

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

Item '4.6 IUTR Negotiation' was changed to '4.6 Parallel Protocol Request

The following agenda items were added during the course of the meeting:

  4.1 Phase Naming

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 ix.netcom.com
Mr. Vincent Bastiani   A# Adaptec, Inc.             bastiani at corp.adaptec.com
Mr. Robert C. Elliott  P  Compaq Computer Corp.     Robert.Elliott at compaq.com
Mr. Don Vohar          A  Fujitsu (FCPA)            dvohar at fcpa.fujitsu.com
Mr. George Penokie     P  IBM Corp.                 gop at us.ibm.com
Mr. Alan Littlewood    P  LSI Logic Corp.           alanl at lsil.com
Mr. Frank Samela       A  Methode Electronics, Inc. franksam at methode.com
Mr. Skip Jones         P  QLogic Corp.              sk_jones at qlc.com
Mr. Ting Li Chan       A  QLogic Corp.              t_chan at qlc.com
Mr. Chuck Micalizzi    V  QLogic Corp.              c_micalizzi at qlc.com
Mr. James McGrath      A# Quantum Corp.             JMCGRATH at QNTM.COM
Mr. Bruce Leshay       V  Quantum Corp.             bleshay at tdh.qntm.com
Mr. Richard Uber       V  Quantum Corp.             duber at tdh.qntm.com
Mr. Duncan Penman      V  Quantum Corp.             duncan.penman at qntm.com
Mr. Gene Milligan      P  Seagate Technology        Gene_Milligan at notes.
Mr. Daniel (Dan) F.    O  Seagate Technology        daniel_f_smith at notes.
Smith                                               seagate.com
Mr. Mayank R. Patel    V  Seagate Technology        patel at cdg.stsv.seagate.
Mr. John Lohmeyer      P  Symbios, Inc.             lohmeyer at ix.netcom.com
Mr. Tracy Spitler      V  Symbios, Inc.             tracy.spitler at symbios.com
Mr. Andrew Brown       V  Symbios, Inc.             andrew.brown at symbios.com
Mr. David Steele       V  Symbios, Inc.             david.steele at symbios.com
Mr. Dave Wehrman       O  UNISYS Corporation        dave.wehrman2 at unisys.com
Mr. Paul D. Aloisi     P  Unitrode Corporation      aloisi at unitrode.com
Mr. Jeffrey L.         P  Western Digital           Jeffrey.L.Williams at wdc.
Williams                  Corporation               com
Mr. Gregory Kapraun    A  Western Digital           Gregory.D.Kapraun at wdc.com

Mr. Bob Warren         V  Western Digital           robert.w.warren at wdc.com

26 People Present

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

4.   SPI-3 Topics

4.1  Phase Naming

George Penokie discussed what to call the two new phases that had previously
been unused.  The consensus was:

Existing Data In phase:        Single Transition Data In
Existing Data Out phase:       Single Transition Data Out
New Data In phase:             Double Transition Data In
New Data Out phase:            Double Transition Data Out

Where it does not matter whether the clocking is done with single transitions
or double transitions, the terms Data In phase and Data Out phase will be

4.2  CRC Proposals

Jim McGrath presented 98-177r0, `Proposal for Parallel SCSI: Increase Transfer
Rate and Improve Error Detection'.  A number of terminology changes were made,
including the naming changes from the above agenda item.  Also, the term
`frame' was changed to `CRC group'.

It was noted that there is no double-transition asynchronous protocol defined.

George Penokie proposed that the double-transition data phases be limited to
16-bit wide buses only.  Besides simplifying the design somewhat (particularly
in the area of pad bytes), it would mean that the P1 signal could be available
for an unspecified purpose.  The group did not close on this idea, preferring
that it get wider exposure before making a decision.

There was a discussion of whether the pad bytes should be transferred before
or after the CRC.  Jim's current proposal has the pad bytes transferred after
the CRC.  Several people argued that the pad bytes should occur first and be
included in the CRC.  The consensus was that the pad bytes will be before the
CRC and the CRC will include both data and the pad bytes.  On an 8-bit bus,
there will be 0, 1, 2, or 3 pad bytes.  On a 16-bit bus, there will be 0 or 1
pad words.  32-bit buses are treated exactly the same as two 16-bit buses,
each with their own REQ and ACK signals (REQQ and ACKQ) and each with their
own CRC generator/checking logic.

The above rules also simplified the CRC generator since the input will always
be a multiple of 32 bits.

There are some boundary cases that needed clarification:

1. A Data Phase with no REQ transitions.  (This by definition is not actually
   a Data Phase.)
2. A Data Phase containing only a CRC without any data.  (Unusual, but
3. A Data Phase containing data followed by CRC. (This is the normal case.)
4. A Data Phase containing a CRC followed immediately by another CRC.
   (Unusual, but allowed.)
5. A Data Phase containing data, then CRC followed immediately by another CRC.
   (Unusual, but allowed.)

It was noticed that there may be some ambiguities regarding entering and
leaving packetized mode.  It appeared that there is a rule in SPI-3 Rev 0 that
prevents the initiator from re-negotiating out of packetized mode: currently,
the target will go to Bus Free phase if the initiator selects it with ATN
while in packetized mode.

There was a discussion about whether the extra setup time on the CRC_Valid
signal is necessary, whether the pad bytes should be inverted, and whether the
extra setup time should be 12.5 ns or some other value.  It was decided that
no changes from Jim's current proposal are necessary (keep the extra 12.5 ns
of setup time and do not invert the pad bytes).

4.3  Learn Mode (Domain Validation)

Jim McGrath presented 98-176r1, Proposal for Parallel SCSI: Domain Validation.
Several improvements were suggested:

o    Both a starting and ending message should be defined.
o    The testing sequence can occur at any time.
o    The testing sequence occurs at the currently negotiated
     speed/width/clocking mode.

Jim plans to revise the proposal for next time.

4.4  Expander Communication

Jim McGrath reported that he does not intend to do any more work on his 98-158
document and it should be dropped from future agenda.

4.5  QAS

This topic was not covered.

4.6  Parallel Protocol Request Negotiation

This item was re-named from IUTR since it includes several new items.  George
Penokie plans to put a proposal on the reflector for consideration at the June
19th meeting.

4.7  Fast-80

Gene Milligan presented 98-153r1.  He noted that the paper copies he passed
out are actually pre-revision 1.  The correct Rev 1 document is on the T10
web/ftp site.

The C1, C2, and C3 capacitance values in Table 6 were changed from 20, 20, 10
pF to 15, 15, 8 pF.  There was some concern that these values may be difficult
to achieve especially if multimode drivers are required.  Jim McGrath
suggested that larger values would be acceptable if the device spacing was
also increased.

Gene noted that the System Deskew Delay description may need some work.  This
time may be used incorrectly in the synchronous data transfer description
and/or its value may need adjustment.

Symbios plans to bring in a proposal that would change the voltage values in
Figure 22 from 1.8 to 1.4 volts.  This is based on the desire to support
2.5-volt chips.

There was some discussion on how the Table 10 voltages were selected although
these had not changed since SPI-2.  There was particular concern over the 3.0
volt specification for Vmin on SE/LVD terminators.  Paul Aloisi pointed out
that single-ended termination does not need to pull up to 2.85 volts; 2.5
volts is all that is required.

Dan Smith presented 98-182r0, Ultra-3 Cable Tests.  Vince Bastiani presented
98-181r0, Fast-80 Eye Pattern Testing.  Vince made several suggestions for
ways to increase data rates still higher than Fast-80 including ISI
compensation, increased drive levels, cancellation of bias at the receiver,
cable skew cancellation, regular clock periods, and data encoding.

5.   Meeting Schedule

The next meetings of SPI-3 Working Group will be:
o    Friday, June 19, 1998 from 9 am to 5 pm in Huntington Beach, CA at the
     Hilton Waterfront Hotel (714-960-7873), hosted by QLogic
o    Tuesday, July 14, 1998 from 9 am to 6 pm in Portland, ME at the Holiday
     Inn By the Bay (207-775-2311), hosted by Digital Equipment Corp.

6.   Adjournment

The meeting was adjourned at 5:00 p.m. on Friday May 22, 1998.

John Lohmeyer                  Email: lohmeyer at ix.netcom.com
Symbios, Inc.                  Voice: +1-719-533-7560
4420 ArrowsWest Dr.              Fax: +1-719-533-7036
Colo Spgs, CO 80907              BBS: +1-719-533-7950

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