[ibis-quality] Minutes from the 15 may 2007 ibis-quality meeting

Minutes from the 15 may 2007 ibis-quality meeting are attached. ARs:

AR: Moshiul send a datasheet for SSTL2
AR: Mike invite Barry Katz to next meeting for [Receiver Thresholds]
discussion
AR: All review IBIS [Receiver Thresholds] and SSTL2 for next call
AR: Mike change 3.2.5 to exempt RLC requirement when [Package Model]
present
AR: Mike delete 3.3.3 from IQ spec
AR: Roy clarify 3.3.2
AR: Mike change 3.3.4 to require a comment for unique +/- diff pair
models  

Mike

Minutes, IBIS Quality Committee

15 May 2007

11-12 AM EST (8-9 AM PST)

ROLL CALL
  Adam Tambone
  Barry Katz
  Benny Lazer
  Benjamin P Silva
* Bob Ross, Teraspeed Consulting Group
  Brian Arsenault
* David Banas, Xilinx
* Eckhard Lenski
  Eric Brock
  Gregory R Edlund
  Hazem Hegazy
  John Figueroa
  John Angulo
  Katja Koller
  Kevin Fisher
* Kim Helliwell, LSI Logic
  Lance Wang, IOMethodology
  Lynne Green
* Mike LaBonte, Cisco
* Moshiul Haque, Micron Technology
  Peter LaFlamme
  Radovan Vuletic, Qimonda
  Robert Haller
* Roy Leventhal, Leventhal Design & Communications
  Sherif Hammad
  Todd Westerhoff
  Tom Dagostino
  Kazuyoshi Shoji
  Sadahiro Nonoyama

Everyone in attendance marked by  *

NOTE: "AR" = Action Required.

-----------------------MINUTES ---------------------------
Mike LaBonte conducted the meeting.

New items:

- Barry Katz has offered to join the meeting next week to help clarify
  issues regarding [Receiver Thresholds].
  - We agreed to discuss [receiver Thresholds] next week.
  - We should also find a spec to show example timing requirements.

AR: Moshiul send a datasheet for SSTL2
AR: Mike invite Barry Katz to next meeting for [Receiver Thresholds] discussion
AR: All review IBIS [Receiver Thresholds] and SSTL2 for next call

AR Review:

- Mike prepare IQ status presentation for IBIS summit
  - TBD
  - Will not be reviewed by the group ahead of the summit.

- David research [Receiver Thresholds] issues
  - Will discuss next week

Continued review of IQ specification 1.1p:

3.2.5.  {LEVEL 3}  [Pin] RLC parasitics are present and reasonable
- Mike inserted a new clause with his last edit:
  "To pass this check the RLC values must be present for all signal
   pins in the [Pin] section, even if [Package Model] is present."
  - Roy pointed that requiring lumped RLC when a better model is
    present is "going backward".
  - In theory it is possible to extract an RLC model from any [Package Model].
    - Kim is writing a "lumpifier" to do that.
- We voted to reverse the sense of the requirement so that RLC is not
  required when [Package Model] is present.

AR: Mike change 3.2.5 to exempt RLC requirement when [Package Model] present

3.3.3.  {LEVEL 3}  [Diff Pin] Vdiff and Tskew correct
- "Tskew" is actually "Tdelay, Tdelay_min, Tdelay_max" in IBIS
- We decided to eliminate the "corresponds to datasheet" language.
- Discussion of how the Tdelay is measured:
  - David suggested that it should be the difference in Vmeas crossing
  - Question: is it measured at the pads or at the pins?
  - Mike said that EDA tools simply change the launch times of + and - signals.
  - Therefore it has to be measured at the pads.
- Discussion of how Vdiff is measured:
  - Moshiul pointed out that [Receiver Thresholds] has Vdiff_ac, similar
    - Bob said that this overrides [Diff Pin] Vdiff
    - ibischk may not check Vdiff_ac conflicts thoroughly
  - Roy pointed out that vendors make Vdiff datasheet limits wider than
    necessary.
  - IBIS Vdiff should be the maximum value, which leads to pessimistic timing
- 3.3.2 is the basic check, 3.3.3 adds only a datasheet check
- We voted to eliminate 3.3.3

AR: Mike delete 3.3.3 from IQ spec

3.3.2.  {LEVEL 3}  [Diff Pin] Vdiff and Tdelay_* complete and reasonable
- This check is not clearly written, in light of the previous discussion.

AR: Roy clarify 3.3.2

3.3.4.  {LEVEL 3}  [Diff Pin] referenced pin models matched
- Kim said the "check to make sure you intended this" is not good language
  for a requirement.
- It was felt that using the same buffer for both sides of a diff pair
  is normal.
  - Mike said that bench measured IBIS files tend to have separate models
    for each side, even if the 2 have nearly identical data.
- If buffer models referenced by the two physical pins of a [Diff Pin]
  are different, comments should be required to explain why.

AR: Mike change 3.3.4 to require a comment for unique +/- diff pair models

Next meeting:

22 May 2007
11-12 AM EST (8-9 AM PST)
Phone: 1.877.384.0543 or 1.800.743.7560
Passcode: 90437837

Meeting ended at 12:16 PM Eastern Time.

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