IBIS Macromodel Task Group

Meeting date: 21 January 2020

Members (asterisk for those attending):
ANSYS:                        Dan Dvorscak
                            * Curtis Clark
Cadence Design Systems:     * Ambrish Varma
                              Ken Willis
                              Kumar Keshavan
Intel:                        Michael Mirmak
Keysight Technologies:        Fangyi Rao
                              Radek Biernacki
                              Ming Yan
                            * Todd Bermensolo
Mentor, A Siemens Business: * Arpad Muranyi
Micron Technology:          * Randy Wolff
                            * Justin Butterfield
SiSoft (Mathworks):           Walter Katz
                              Mike LaBonte
SPISim:                     * Wei-hsing Huang
Teraspeed Labs:             * Bob Ross

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

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Opens:

- Arpad noted that the meeting scheduled for the 28th is cancelled because of
  DesignCon.

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Review of ARs:

- Randy to send the reply to the BIRD198 authors after final review by the small
  working group.
  - Done.  Arpad noted that the authors had replied already.  They largely agree
    with our feedback except for one issue.  They will consider drafting a new
    version.
  
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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 January 14
meeting.  Randy moved to approve the minutes.  Bob seconded the motion.
There were no objections.

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New Discussion:

BIRD201:
Arpad asked if there was anything to discuss and noted that the BIRD was
introduced at the previous Open Forum meeting.  Bob noted comments he had made
at the Open Forum meeting.  He preferred that sections of the BIRD that
contained links to existing text be replaced with the actual text.  He noted
that we should probably do it in ATM.  Arpad agreed that the editorial group
usually handles changes made after the BIRD is approved, and we could handle
these changes in ATM and submit a new version prior to approval.  Walter noted
that he would have a presentation on this topic at the DesignCon IBIS Summit.

AMI String parameter questions (continuing discussion from previous meeting):
Curtis shared a few points from an email discussion with Arpad about why he
felt the "" characters were required as part of the String parameter value
passed to the model.  He noted that as of 5.1.2 the parser returned the ""
characters as part of a String parameter's value, that he had encountered many
models that required the "" characters and none that failed with them, and that
a Table of String parameters would be impossible to parse reliably without ""
if the values contained spaces.  Arpad also noted that he and Curtis had agreed
that the spec currently contains no examples of parameter strings that include
a String parameter.

Ambrish agreed that "" were required if the String's value contained spaces.  He
noted that the models he and Curtis had collaborated on getting working had only
required "" for values that contained spaces.  Curtis agreed that those models
had contained filename parameters and other non-filename parameters that also
included spaces, but Ambrish was correct that parameters whose values did not
include spaces had not required the "" characters.  Curtis said he thought he'd
encountered other models that required "" characters for all String values.

Walter noted that this issue had in fact been settled during the original
discussions about 10 years ago.  He said that the clear conclusion from those
discussions had been that every String parameter's value must be surrounded by
the "" characters.  He noted that this was captured in the syntax description
for the ami_parameters_in argument on pg. 205 of IBIS 7.0 (item #9).  Walter
noted that the syntax description and BNF on page 205 were originally created
for the ami_parameters_in string, and it was in later discussions that Ambrish
and others had suggested it also be applied to the .ami file itself.

Wei-hsing asked if it was legal to have an escaped " character (\") within the
double quotes.  Walter said it was not legal.  No " is allowed inside the
string.

Walter noted that the text on pg. 205 (item #9) also answered Michael M.'s
question about empty strings,
  "Empty string literals are denoted by two successive double quote characters."
  
Arpad said his recollection had been that the text on 205 applied to the
information in the .ami file, but now that Walter had reminded us that it
applied to the ami_parameters_in string the issue appears to be settled.
Arpad asked if this required a clarification BIRD for readability or to add more
examples.  No one answered, so the group seemed to feel the issue was fully
resolved.

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

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Next meeting: 04 February 2020 12:00pm PT
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IBIS Interconnect SPICE Wish List:

1) Simulator directives