IBIS Macromodel Task Group

Meeting date: 26 September 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.

--------------------------------------------------------------------------------
Opens:

- None.

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Review of ARs:

Kinger: Provide BIRD223.1 draft2 with minor cleanup changes to Lance to post
        to the IBIS Open Forum BIRDs page as BIRD223.1.
        - Done.

Michael: Send out draft8 of the [AMI Test Data] proposal including more feedback
         from the ATM meeting.
         - Done.
         
Michael: Develop a full syntactically complete example demonstrating the
         [AMI Test Data] proposal.
         - In progress.  Michael said he would work on this after we get the
           proposal itself more settled.

--------------------------
Call for patent disclosure:

- None.

-------------------------
Review of Meeting Minutes:

Arpad asked for any comments or corrections to the minutes of the September 19th
meeting.  Ambrish moved to approve the minutes.  Michael seconded the motion.
There were no objections.

--------------
New Discussion:

[AMI Test Data] proposal:
Michael reviewed draft8, which had been sent to the ATM list prior to the
meeting.  He noted that the major changes were related to the waveform file
Sub-Params, which are now Input_impulse_File, Input_waveform_File, and
Golden_waveform_file.

Michael noted that the proposal explicitly states that Input_impulse_file is
required for all combinations of Tx or Rx and statistical or time domain.

Michael said that Input_waveform_file is the time domain replacement for the
original Stimulus_file (now removed), which had been overloaded and used for
statistical and time domain cases.  Input_waveform_file is required for time
domain and illegal for statistical configurations.  Michael noted that the
Input_waveform_file definition describes the contents of the file for the Tx
and Rx cases.  For a Tx, the contents are a sampled waveform representing the
"digital" state transitions.  For an Rx, the contents are an analog waveform
representing a stimulus convolved with the channel impulse response.

Michael said that he had not created a table to describe the waveform file
subparameters' contents for the combinations of Tx or Rx and statistical or
time domain.  He said he thought that with the new separate "impulse" and
"waveform" input file subparameters, the descriptive text was now clear.  He
asked whether anyone thought a table was necessary.  No one said they thought
a table was necessary.

Michael noted that this version explicitly states that the changes should be
added after Section 10.4.  Therefore, the changes will occur after the function
signature descriptions upon which they rely.  He said the changes will occur
before advanced topics such as retimer flows, and they should contain no
references to anything defined later.

Michael asked whether everyone thought it was clear that this proposal applies
to individual [Model]s, and it does not require a full Tx, channel, Rx, setup.

Ambrish said that Input_waveform_file is analogous to the "wave" parameter in
the AMI_GetWave function signature.  He suggested that if the text made that
connection to "wave", then it wouldn't have to provide its own explanation of
the contents of Input_waveform_file.  Michael agreed, and the group adopted
language stating that the contents of Input_waveform_file are "equivalent" to
the contents of the "wave" argument.  Arpad suggested that we make it clear to
the reader that there's no need for a Tx when testing an Rx model with this
proposal.  In response, the group added text stating that the contents of the
Input_waveform_file for an Rx were equivalent to the "wave" input that would be
presented to the Rx AMI_GetWave during a normal channel simulation that included
Tx and Rx AMI executable models.

Bob asked whether it was a good idea to include IBIS keyword descriptions in the
AMI section.  Michael said the new keywords relied on information about AMI
function parameters and AMI Reserved Parameters, so the keyword definitions had
to come after those sections.  Ambrish said this raised an interesting point.
Since this proposal is concerned with testing AMI models, perhaps it should be
placed at the end of the AMI section, i.e., the testing portion comes last.
Michael said there were two primary reasons he had introduced this proposal in
the middle of the AMI chapter.  First, the last subsection of the AMI chapter is
just a list of all the AMI Reserved Parameters, and he thought these changes
should go before that.  Second, he had been frustrated at having to jump around
to multiple places in IBIS 7.2 in order to fully understand and assemble
summaries of the information upon which his proposal depended.  Therefore, he
had attempted to put the new section as close as possible to the sections on
which it relied.  Michael noted, however, that it may make sense to include
this proposal a bit later than 10.4, so it would appear after all the flow
discussions.

Curtis noted some language about "number of columns" and aggressors that was
not relevant to Input_waveform_file.  Michael agreed that these were hold
overs from the original Stimulus_file discussion and removed them.

Ambrish asked whether the name of the [Waveform] keyword was descriptive
enough.  Michael suggested [AMI Test Configuration] instead.  The group agreed
to change [Waveform] to [AMI Test Configuration].

Bob suggested that a keyword hierarchy tree entry should be added for these
new keywords.  He also asked whether we should consider adding the associated
"end" keywords (e.g., [End AMI Test Configuration]).  Bob said that we might
want a new table (or to add to an existing table) to define all the rules for
what subparameters are required, illegal, optional under what conditions.
Michael said he would add a table with this information. 

Michael said he would send out draft9.

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

New ARs:

Michael: Send out draft9 of the [AMI Test Data] proposal including more feedback
         from the ATM meeting.

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Next meeting: 03 October 2023 12:00pm PT
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IBIS Interconnect SPICE Wish List:

1) Simulator directives
