IBIS Macromodel Task Group

Meeting date: 15 March 2022

Members (asterisk for those attending):
Achronix Semiconductor:       Hansel Dsilva
Amazon:                       John Yan
ANSYS:                      * Curtis Clark
                            * Wei-hsing Huang
Cadence Design Systems:     * Ambrish Varma
                              Jared James
Google:                       Zhiping Yang
Intel:                      * Michael Mirmak
                              Kinger Cai
                              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
Siemens EDA (Mentor):       * Arpad Muranyi
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:

- None.

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Review of ARs:

- Arpad to send draft 16 of BIRD213.1 to the ATM list.
  - Done.
  
- Ambrish to add Table -> String changes to draft 16.
  - Done.  Ambrish had sent draft 17 to ATM
  
- Michael to send draft 4 of the Root Name Clarifications BIRD to ATM.
  - 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 March 8th
meeting.  Michael moved to approve the minutes.  Randy seconded the motion.
There were no objections.

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New Discussion:

BIRD213.1 draft 17, PAMn:
Ambrish shared draft 17 and reviewed the changes he'd made to replace the use of
Tables with String parameters for PAM_Offsets and PAM_Thresholds.  In the
PAM_Thresholds Usage Rules, the changes were primarily replacing references to
values in "Row N" in the Table to references to "Value N" in the String.
Ambrish said the biggest changes were actually to the Example(s) and made them
simpler.  Arpad said he had been pleasantly surprised at the limited scope of
the required changes.

Arpad started draft 18 to incorporate new changes.

Randy and Arpad asked if the placeholder values in the Examples should contain 3
numerical values.  Arpad then said keeping 3 might be helpful and emphasize the
fact that the PAM4_Thresholds and PAM4_Offsets parameters' values in the .ami
file are just placeholders.  The group decided to change all the numeric values
to 0.0 but keep some scientific notation values as an example of how they can
be done.

The group reviewed and accepted several editorial suggestions from Bob, Randy
and Arpad.

Arpad had questioned the following sentence in Modulation_Levels Usage Rules:
   If neither Modulation nor Modulation_Levels are defined, then the Modulation
   shall be NRZ.
He said we should be careful about saying "shall be NRZ", because the
Modulation_Levels parameter is an Integer, not a string.  Curtis and Fangyi
suggested the last "Modulation" in the sentence should be lower case, since it
is talking about the modulation scheme not the value of a parameter.  Michael
then added that we should say "must", since we generally use that term when
referring to things that the EDA should do, where "shall" is used to refer to
parser enforceable rules.  The group agreed to change the sentence to:
   If neither Modulation nor Modulation_Levels are defined, then the modulation
   scheme used by the EDA too must be NRZ.

Arpad again questioned the sentence on pg. 228 in the description of the wave
parameter:
  It is assumed that the electrical interfaces to both the driver and receiver
  are differential.

Walter and Randy said even if the signal is single-ended, it's made differential
before passing it into the AMI executable model.  Michael asked if we should
change "electrical interfaces".  Fangyi suggested that the two-paragraph block
that began with "For NRZ models..." and the two-paragraph block that began with
"For PAM4 models..." were both redundant and should be removed.  The group
agreed, and Arpad captured the new changes for pg. 228 in draft 18.  The
sentence in question was removed by these changes.

Ambrish then noted that on page 278 of IBIS 7.1, the section 10.7 introductory
paragraph had to be rewritten to accommodate the new BIRD.  The group worked on
modifying the language.  Arpad captured the changes.  Discussion of this section
will continue at the next meeting.


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

AR: Arpad to send draft 18 of BIRD213.1 to the ATM list.
    
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Next meeting: 22 March 2022 12:00pm PT
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IBIS Interconnect SPICE Wish List:

1) Simulator directives