Minutes, IBIS Quality Committee

13 Mar 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
  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.

AR Review:

- David write 4.1.4a requiring 4.0 C_comp subparams to achieve level 4
  Done. Feedback from 2 people. Waited for this meeting to update.

- Mike make agreed 2.2 - 2.5 changes and post new draft spec
  TBD

New items:

- David's rewrite of 4.1.4a:
  - Comments were received saying that the change incorrectly states that
    C_comp values are not needed for circuit branches corresponding to the
    open sides of open_source and open_drain outputs.
    - In some cases the structures are still present but turned off.
      Hence the capacitance is still present.
  - Moshiul said that open-drain outputs might have a power clamp
    structure even if there is no pullup.
    - David pointed out that in this case displacement currents would
      go to the clamp source rail, not the pullup rail.

AR: David revise 4.1.4a based on feedback about open-xx outputs

- David's proposal to clarify 4.3:
  - David wrote in email "Id like to propose that we add some additional
    explanation to Section 4.3 of the IQS, re: what Vcc-relative really means."
    - It does not make clear that the voltage column in Pullup tables is
      both offset and inverted from absolute voltage measures.
  - This could be an issue for those who are less familiar with IBIS.
    - Mike suggested that the IQ spec should help people who don't know
      IBIS well.
  - We discussed the idea of adding a picture.
  - It was agreed that we could add a table with 3 columns and 3 rows.
    - The columns would be:
      - Absolute voltage
      - IBIS I/V table voltage
      - Current

AR: David clarify voltage inversion in 4.3 and add example table

- Mike suggested suggesting the IBIS Model Review Committee in the IQ spec
  - We agreed

AR: Mike add mention of IBIS Model Review Committee in the IQ spec

- Duplicate S_overshoot_low and S_overshoot_high requirements in 4.2:
  - David sent email pointing out that S_overshoot_low and S_overshoot_high
    requirements are set in both the section 4.2 introduction and in 4.2.13.
  - We decided to strike the language from the 4.2 introduction
  - Kim also noted that 4.2.13 is incorrectly declared a level 3 check.

AR: Mike drop s_overshoot sentence from 4.2 and change 4.2.13 to level 2

- Discussion of document formatting options:
  - Now that IQ is an MSWord file we COULD have figures if we wish.
  - This would not translate to text when/if that is required.
  - No one liked the idea of adding ASCII graphics to an MSWord document.
  - We decided to hold off on this until there is a real need.
  - Mike mentioned that the latter half of the document still needs formatting
    cleanup.

- 2.6.  {LEVEL 2}  [Source] is complete
  - This is not a functional IBIS quality issue.
  - We decided to move this to section 5.

- 2.7.  {LEVEL 2}  [Notes] is complete
  - This is not a functional IBIS quality issue.
  - We decided to move this to section 5.

AR: Mike move 2.6 and 2.7 to section 5

- 2.8.  {OPTIONAL} [Disclaimer] and [Copyright]
  - This is not a functional IBIS quality issue.
  - These do not benefit IBIS users to any significant degree.
  - Some discussion of [Disclaimer]:
    - The typical IBIS disclaimer implies that the information is not
      guaranteed.
    - Yet, the IBIS file is becoming the "real datasheet"
      - Modern datasheets tend to lack information they used to have.
        - Used to have I/V curves
        - Some new datasheets lack timing test fixture parameters
  - Mike asked if we should we retain the [Copyright] requirement?
    - From a legal perspective it helps prove the copyright date.
    - We decided that everyone understands copyright well enough.
  - We decided to strike this one completely

AR: Mike delete 2.8

- 3.1.1.  {LEVEL 2}  [Package] must have typical values
  - This check is already implemented as written in IBISCHK
    - Should we give the minimum IBISCHK rev required?:
      - It is known that IBISCHK v4.0.2 catches it
      - IBISCHK 1 probably did also, but we don't know
  - We could strike this check
  - Mike suggested changing it to a requirement for min and max values:
    - The IBIS spec does not require them.
    - But they are needed for level 2 analyses that are not optimistic
    - David asked how a package engineer using a tool like Sigrity would
      obtain min and max values:
      - Kim said that the common algorithm is to get highest and lowest
        values found among pin RLCs.
      - Mike added that his audit process checks [Package] against this.
    - Moshiul asked if power/ground pins should count toward the min/max:
      - Maybe this is why some max [Package] numbers are very large.
      - We agreed that for a level 2 check only signal pin RLC values
        should be considered when deriving min/max [Package]
    - We decided to require min and max values derived from signal pin RLC
    - Different methods could be waivered with a note about how it is
      extracted
    - Kim said that how min/max is extracted should be documented anyway.

AR: Mike change 3.1.1 to a level 2 min/max [Package] requirement

Next meeting:

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

Meeting ended at 12:07 PM Eastern Time.