IBIS Macromodel Task Group

Meeting date: 29 August 2023

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

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

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Opens:

- Several regular attendees said they would not be able to attend the meeting
  scheduled for September 5th.  The group decided to cancel the meeting on
  September 5th.

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Review of ARs:

Michael: Send out draft6 of the [AMI Test Data] proposal including more
         feedback from Fangyi and the ATM meeting.
         - Done.

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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 August 22nd
meeting.  Michael moved to approve the minutes.  Ambrish seconded the motion.
There were no objections.

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New Discussion:

Issues with BIRD223:
The group continued the previous week's discussions on how best to manage the
logistics of correcting the issues Arpad had found in BIRD223, which had
already been approved by the Open Forum.  Randy and Curtis had cited precedent
for documenting minor editorial issues in approved BIRDs in the known issues
document for the current version of the IBIS specification.  Bob had said that
he would prefer to capture the changes in a new BIRD223.1.

Bob said he had investigated since the last meeting, and BIRD29.2 had been
issued as a fix of the already-approved BIRD29.1.  So, we have precedent for
creating a .x revision update of an approved BIRD.

Bob said that there were several additional changes that followed from the
editorial issues Arpad had noted.  He said the parameter tree changes were
inconsistent with some of the keyword descriptions, in particular the question
of what keywords can appear in the .ibs file.  Kinger agreed.  He said that
originally [Device SPIM] had been allowed in a .spim file or directly in a .ibs
file.  However, after discussions in ATM, the decision had been made to include
all SPIM related keywords exclusively in the .spim file, except for [Device
SPIM Group], which appears in the .ibs file and serves as the link to the
.spim file.  Kinger agreed that the example for [Device SPIM Group] had not
been updated and incorrectly stated that [Device SPIM] could appear in the .ibs
file itself.  Randy and Kinger then noted that Table 2 also mistakenly stated
that [Device SPIM] was optional in a .ibs file.

Randy and Curtis agreed that the scope of the changes had grown beyond what
could reasonably be handled with an entry in the known issues document.  Kinger
agreed and said he would prepare a draft1 of a BIRD223.1 for the ATM group to
review.

Bob said that he would have no problem with the various SPIM keywords appearing
directly in the .ibs file.  Arpad noted that the closest parallel in existing
keywords had been the package modeling keywords.  However, the SPIM keywords
contained lots of entirely new information, so we had decided to keep SPIM
information in a separate .spim file.  The group decided to leave this as it
had been decided previously (no change).

[AMI Test Data] proposal:
Michael reviewed the changes in draft6, which he had sent to the ATM list prior
to the meeting.  He said that there were no changes to the main [AMI Test Data]
keyword.  The [Waveform] keyword had been updated to support PAMn, and
additional clarifications to Clock_input and Clock_output had been made.

Ambrish noted that the [AMI Test Data] keyword's Other Notes entry stated that
it scoped the [Waveform] keyword, but this was done prior to [Waveform] being
defined.  He suggested that it would be clearer to move this statement on
scoping to the [Waveform] keyword's Description.  Michael agreed and noted the
change.

Ambrish expressed concern over the [AMI Test Data] keyword's Other Notes text:
  "...may encompass impulse response comparisons, time domain response
   comparisons or both."
He said this language might give a first-time reader the impression that we
are comparing impulse responses generated by different tools.  In general, he
said we have to step back and be careful that things that the ATM group has been
discussing for some time would be easily understood by first-time readers.

Arpad asked if we should be more precise about how we define a "channel
response" and call it "channel impulse response".  Michael said he had been
attempting to avoid creating a table defining what is meant by "channel
response" for each of the four possible combinations of Tx or Rx and statistical
or time-domain.  He said he had tried to define the meaning of the input to the
Tx in the time domain case, (i.e., the "digital" stimulus waveform), and then
generally described the possible contents of the "channel response" for the
other three cases.  Michael said he could revisit the language and add "impulse"
for clarification.

Ambrish found the description of Sample_interval lacking in detail.  Michael
confirmed that some of these required inputs relied upon the definitions of the
AMI function signatures.  Ambrish said this was okay, but he noted that the AMI
sections appeared later in the specification.  He suggested we add a reference
to the section containing the AMI function definitions.  Michael said he would
address this either by adding a reference or changing the location of the
proposed new text so that it occurred after that AMI section.

Michael said he would send out a draft7 incorporating these changes and the
changes Fangyi had sent via email.

- Ambrish: Motion to adjourn.
- Curtis: Second.
- Arpad: Thank you all for joining.

New ARs:

Kinger: Send out draft1 of BIRD223.1 with the changes and updates noted during
        the ATM meeting.

Michael: Send out draft7 of the [AMI Test Data] proposal including more feedback
         from Fangyi and the ATM meeting.

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Next meeting: 12 September 2023 12:00pm PT
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IBIS Interconnect SPICE Wish List:

1) Simulator directives
