IBIS Macromodel Task Group

Meeting date: 13 December 2022

Members (asterisk for those attending):
Achronix Semiconductor:       Hansel Dsilva
Amazon:                       John Yan
ANSYS:                      * Curtis Clark
                            * Wei-hsing Huang
Aurora Systems:             * Dian Yang
Cadence Design Systems:     * Ambrish Varma
                            * Jared James
Google:                       Hanfeng Wang
                              GaWon Kim
Intel:                      * Michael Mirmak
                            * Kinger Cai
                              Chi-te Chen
                              Alaeddin Aydiner
Keysight Technologies:        Fangyi Rao
                              Majid Ahadi Dolatsara
                              Ming Yan
                              Radek Biernacki
                              Rui Yang
Luminous Computing            David Banas
Marvell                       Steve Parker
Mathworks (SiSoft):           Walter Katz
                              Mike LaBonte
Micron Technology:          * Randy Wolff
                              Justin Butterfield
Missouri S&T                  Chulsoon Hwang
                              Yifan Ding
Rivos                         Yansheng Wang
SAE ITC                       Michael McNair
Siemens EDA (Mentor):       * Arpad Muranyi
Teraspeed Labs:             * Bob Ross
Waymo:                        Zhiping Yang
Zuken USA:                  * Lance Wang

The meeting was led by Arpad Muranyi.  Curtis Clark took the minutes.

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Opens:
- Arpad noted that the meeting on December 6th had been cancelled.

- Arpad and the group decided that the December 20th meeting will be held as
  normally scheduled, since we are actively reviewing Kinger's BIRD proposals.
  
- Regularly scheduled upcoming meetings that are cancelled:
  - December 27, 2022 - Holidays
  - January 03, 2023 - Holidays
  - January 31, 2023 - week of DesignCon

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Review of ARs:
  
- None.

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Call for patent disclosure:

- None.

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Review of Meeting Minutes:

Arpad asked for any comments or corrections to the minutes of the November 29th
meeting.  Michael moved to approve the minutes.  Ambrish seconded the motion.
There were no objections.

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New Discussion:

Standard Power Integrity Model (SPIM) BIRD draft:
Kinger reported that he had received extensive feedback from Arpad, Randy, and
Bob, and they had met to review it.  He said he was actively working on a
draft6.  Kinger reviewed some of the important changes.

- Kinger had consolidated and streamlined some text in the Introduction, and he
  had added some upfront explanations of terminology to the initial paragraph,
  per feedback from Bob.  Bob and Randy noted that some portions of the BIRD's
  Introduction section should be included in the additions to the specification
  itself, perhaps as an introductory section describing SPIM.
- Arpad had suggested replacing most instances of ".spim files" with "SPIM",
  since we are talking about the concept of SPIM, and SPIM models can appear
  in .ibs files as well as .spim files.
- Arpad had suggested stating that the purpose is "supporting full PDN design",
  where the previous language mentioned supporting "AC impedance analysis in
  frequency domain", which is just one method for supporting PDN design.
- Kinger said S-parameters in Touchstone files are commonly used in the
  industry, but he had also added mention of the fact that IBIS-ISS subcircuits
  can also be used in SPIM modeling in IBIS.
- Arpad had suggested Kinger generalize the derivation section (equations 1 
  through 7) to M sensing ports instead of simply 1 sensing port.  Randy noted
  that the "N+1" appearing in the original derivation might have led to
  confusion with N+1 terminals referring to N ports and a common reference in
  other sections.  With the generalization to M sensing ports in the derivation,
  we now have "N+M".  Kinger observed that in the final equation (7) the upper
  limit of the sum index is still "N", taking advantage of the fact that we know
  weighting terms for i > N are all zero.
- Bob had noted that [Chip SPIM Group] is illegal in a .spim file and can only
  appear in a .ibs file.   Randy said this keyword needed much more information
  in its Usage Rules, and he suggested using the [Interconnect Model Group] as
  a reference for what should be included.  They suggested that the example in
  the section be cleaned up, and made-up names should be provided as opposed to
  <> delimited placeholders.  Also, each [Chip SPIM Group] in the example needs
  its own [End Chip SPIM Group].
- [SPIM Rail] - Bob, Randy, and Arpad said the Usage Rules for this keyword
  needed to clearly state that signal_name or bus_label values from [Pin],
  [Pin Mapping] or [Bus Label] keywords are used here.  Kinger modified the
  Usage Rules during the discussion.

Arpad said discussion would continue next week.  He asked people to review the
new draft6 Kinger would send out.

- Bob: Motion to adjourn.
- Kinger: Second.
- Arpad: Thank you all for joining.

AR: Kinger to send out draft6 of the SPIM BIRD containing changes reviewed and
    discussed in today's meeting.
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Next meeting: 20 December 2022 12:00pm PT
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IBIS Interconnect SPICE Wish List:

1) Simulator directives
