IBIS Macromodel Task Group

Meeting date: 10 January 2017

Members (asterisk for those attending):
ANSYS:                      * Dan Dvorscak
                              Curtis Clark
Broadcom (Avago):             Xingdong Dai
                            * Bob Miller
Cadence Design Systems:     * Ambrish Varma
                              Brad Brim
                              Kumar Keshavan
                              Ken Willis
Cisco:                        Seungyong (Brian) Baek
eASIC:                        David Banas
                              Marc Kowalski
Ericsson:                     Anders Ekholm
GlobalFoundries:            * Steve Parker
IBM                           Luis Armenta
                              Trevor Timpane
Intel:                      * Michael Mirmak
Keysight Technologies:        Fangyi Rao
                            * Radek Biernacki
                              Ming Yan
Maxim Integrated Products:    Hassan Rafat
Mentor Graphics:              John Angulo
                            * Arpad Muranyi
Micron Technology:          * Randy Wolff
                              Justin Butterfield
QLogic Corp.:                 James Zhou
                              Andy Joy
SiSoft:                     * Walter Katz
                              Todd Westerhoff
                            * Mike LaBonte
Synopsys:                     Rita Horner
                            * Kevin Li
Teraspeed Consulting Group:   Scott McMorrow
Teraspeed Labs:             * Bob Ross
TI:                           Alfred Chong


The meeting was led by Arpad Muranyi.

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

- Arpad: Mike LaBonte is taking minutes.
- Arpad: We will cancel the Jan 31 meeting which conflicts with DesignCon.
  We will meet Jan 17 and 24.

-------------
Review of ARs:

- AR: Walter to email his example and BIRD 158.4 to the ATM list.
  - Done

- AR: Mike LaBonte to update the "IBIS 6.2 BIRD Candidates" to rev 7 and send it
    to the ATM list.
  - Done

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

- None.

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

- Arpad: Does anyone have any comments or corrections? [none]
- Michael M.: Motion to approve the minutes.
- Bob Ross: Second.
- Arpad: Anyone opposed? [none]

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

BIRD147.5:
- Arpad noted that BIRD 147.5 had been recently emailed, and that it had been scheduled for
  a vote in the previous Open Forum meeting, but that had been deferred. Bob Miller showed
  the BIRD. He said there were issues with BCI_GetWave_Block_UI related to rounding. It
  needed to be an integer and BIRD 147.5 has been tweaked for that. The parameter name was
  now BCI_Message_Interval_UI and the definition had been changed. It informs the EDA tool
  what the interval wants to be. It is wide open as to what the optimization should be. Bob
  Ross said the Type should be Integer. Bob Miller changed Type to Integer.  - Bob Miller
  proposed that models should be forgiving if AMI block size does not exactly match the
  requested frequency, and that BCI_Training_UI should be extended by tools to synchronize
  with the message interval. The expected number of adaptation steps should be achieved.
  Radek Biernacki said the definition probably should be more precise. When training time ends
  one more GetWave should be called before actually ending training. Ambrish Varma said that
  that was in the notes section. Radek said we would need to be careful about interactions
  with BCI_State. Bob Miller believed there would not be any interactions with that. Ambrish
  said if the model does not end training the EDA tool will take over. Bob Miller said that
  to have bit by bit accuracy the model would have to guarantee that it exactly matches
  device behavior on any EDA platform. Mike LaBonte asked if there should be a rule that
  Message_Interval_UI must be less than Training_UI, so ibischk could check it. Bob Miller
  said models would not necessarily message every time they were called, and that performance
  might degrade about 15% if the message window is long. Ambrish Varma suggested it might be
  better to add examples to the specification to illustrate the best practice.

- AR: Bob Miller to update BIRD147.5


BIRD 187.1:
- Michael Mirmak showed the BIRD. He noted that Curtis Clark had suggested removing "Type
  Value" because there is no such thing. The Format for Usage Out is not used by EDA tools
  except for Table. The four rules are all expressed in one paragraph. Michael said BIRD would
  be revised, trying to get down to one simple statement in one location, maybe two. Radek
  Biernacki said the sentence with "except" twice was confusing. It was not clear how to
  display Out data. Bob Ross said we had a list of rules on IBIS 6.1 page 194. He asked if
  the new rules would be moved there. Michael Mirmak said the question was if the rule should
  be stated in each place where it applies, or if it should be stated only once. Some rules
  can be far away in the document. Arpad Muranyi said there could be references made to a
  single location. Mike LaBonte added that including a reference to the original definition
  helps us to know all of the places where a duplicated rule would need to be changed. Bob
  Ross said we might want to explain Usage Out. Michael Mirmak agreed that very little had
  been stated about Usage Out.

AR: Michael Mirmak to send an update to BIRD 187.1.


BIRD158:
- Radek Biernacki said the example needed to be discussed, and that once we agree, it
  should to be ported to the new BIRD template. Bob Ross asked if we really wanted another
  solution, since we already had a solution.  He said we had multi-lingual, asking if we
  need a parameter. Ambrish Varma noted the parameter did not have to be in an AMI file. Bob
  Ross said we could link it through IBIS-ISS. Radek said a simpler solution would be to
  just give the Touchstone file name. He said if it remained Model_Specific it would always
  be experimental. Ambrish said that that is provided in the specification if called from an
  [External Model] parameter. Arpad Muranyi said tools wouldn't know what to do with that. Ambrish
  said it should be regarded as an analog model. Walter Katz asked what bad thing would happen
  if it became a Reserved_Parameter. Ambrish said doing so expected the EDA tool to construct
  a canned circuit, and that we already had a right way to do it. Walter said there was no
  right way for frequency domain simulation. Radek agreed there was no right way, but it was
  just an approximation of device behavior. It was "a" way. Arpad asked if everything was
  IBIS file-centric or AMI-centric.

- Arpad: Thank you all for joining.

-------------
Next meeting: 17 January 2017 12:00pm PT
-------------

IBIS Interconnect SPICE Wish List:

1) Simulator directives
