[ibis-macro] Minutes from the 12 Mar 2013 ibis-atm meeting

  • From: Mike LaBonte <mike@xxxxxxxxxxx>
  • To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
  • Date: Wed, 13 Mar 2013 13:23:58 -0400

Minutes from the 12 Mar 2013 ibis-atm meeting are attached.

IBIS Macromodel Task Group

Meeting date: 12 Mar 2013

Members (asterisk for those attending):
Agilent:                    * Fangyi Rao
                            * Radek Biernacki
Altera:                     * David Banas
                              Julia Liu
                              Hazlina Ramly
Andrew Joy Consulting:        Andy Joy
ANSYS:                        Samuel Mertens
                            * Dan Dvorscak
                            * Curtis Clark
                              Steve Pytel
                              Luis Armenta
Arrow Electronics:            Ian Dodd
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
                              Feras Al-Hawari
                              Brad Brim
                              Kumar Keshavan
                              Ken Willis
Cavium Networks:              Johann Nittmann
Celsionix:                    Kellee Crisafulli
Cisco Systems:                Ashwin Vasudevan
                              Syed Huq
Ericsson:                     Anders Ekholm
IBM:                          Greg Edlund
Intel:                      * Michael Mirmak
Maxim Integrated Products:    Mahbubul Bari
                              Hassan Raghat
                              Ron Olisar
Mentor Graphics:            * John Angulo
                              Zhen Mu
                            * Arpad Muranyi
                              Vladimir Dmitriev-Zdorov
Micron Technology:            Randy Wolff
                              Justin Butterfield
NetLogic Microsystems:        Ryan Couts
Nokia-Siemens Networks:       Eckhard Lenski
QLogic Corp.                  James Zhou
SiSoft:                     * Walter Katz
                            * Todd Westerhoff
                              Doug Burns
                            * Mike LaBonte
Snowbush IP:                  Marcus Van Ierssel
ST Micro:                     Syed Sadeghi
Teraspeed Consulting Group:   Scott McMorrow
                            * Bob Ross
TI:                           Casey Morrison
                              Alfred Chong
Vitesse Semiconductor:        Eric Sweetman
Xilinx:                       Mustansir Fanaswalla
                              Ray Anderson

The meeting was led by Arpad Muranyi


- None

Call for patent disclosure:

- None

Review of ARs:

- Mike post updated BIRD 147
  - Done

- Arpad try to apply BIRD 158 shortcut language to his BIRDs 116-118
  - In progress

New Discussion:

Interconnect Update:
- Michael M: There was no meeting last week
  - The current agenda is still being worked on

Arpad showed "Analog BIRD Review":
- Michael M: The idea is to have relatively few BIRDs
  - Members are free to ask to schedule any of these BIRDs for a vote
- Arpad: Is there a deadline to get into the next IBIS version?
- Michael M: According to plan that would have been March 1
  - We can still get the BIRDs approved will still help
  - Having unvoted BIRDs is the worst case
  - Only 1 BIRD is now approved
- Bob: We need to make tough choices, including rejecting BIRDs
- Mike L: The next release should be a permanent Open Forum agenda item

- slide 2:
  - Arpad: Most of these are my BIRDs
    - 116.1, 117.4, 118.3, 129, 145.2, 153
  - Arpad went over the status of each BIRD in detail
  - Arpad: They need to be converted to the new format
    - Then I would like to vote to vote on them

  - Walter: [External Circuit] was targeted for package interconnect, not on-die
    - BIRD 145 should not go through
    - It is fundamentally flawed
  - Arpad: BIRD 145 is not absolutely necessary
    - Do not agree the idea is fundamentally flawed
    - Are you saying BIRD 116 should be removed too?
  - Walter: I am only saying we should not work on [External Circuit]
    - Not even to add IBIS-ISS to it
  - Arpad: It's not a complicated addition
  - Bob: Technically we already support on-die interconnect with [External 
    - BIRD 153 should be moved to a separate file
  - Arpad: We should all look these BIRDs over and be ready to vote
  - Ambrish: Should we discuss BIRDs 116-118 before converting to new format?
  - Michael M: Keywords are added to the spec, but there is no requirement to 
support them
    - No one has used transit time, for example
  - Radek: This does not end the analog model issue
    - In [External Model] everything has to be in IBIS format
    - It is a separate issue whether IBIS-ISS will be usable
  - Arpad: These BIRDs may not address every problem
    - But they address enough
    - Meanwhile we can work on the long term solution
  - Walter: [External Circuit] does not come close to solving the analog model
    problem we have today
    - It would be a waste of time
  - Arpad: It is just adding a language, not a waste of time
  - Bob: The BIRDs should reference IBIS 5.1, not 5.0
    - Once this is done we need a parser for it
    - That is the best way to adopt these BIRDs
    - It will take funding to get this done
  - Arpad: It is a short term solution
  - Bob: It might take 2 years

-  Michael M: Next OF meetings are this Friday and Apr 15
  - Keep tat in mind if we want to set a new deadline date

Fangyi showed "Redriver Background" (from recent DesignCon):
- http://www.eda.org/ibis/summits/jan13/bari.pdf
- slide 7:
  - Fangyi: In a redriver there is no retiming
    - It can be non-linear
    - It can't go in the current flow
  - Arpad: For very long channels can many of these be cascaded?
  - Fangyi: Yes, this BIRD supports that
- slide 8:
  - Fangyi: It has to be modeled to behave like an analog circuit
    - It is driven by an analog waveform, not an event
    - The redriver TX is different from a regular TX
  - Michael M: Is this limited to bit by bit time domain simulation?
  - Fangyi: This is focused on time domain
    - Statistical is possible, but there are practical issues
    - For example, how to model device internal noise
  - Todd: Does the BIRD say it is for time domain?
  - Fangyi: No
- slide 7:
  - Michael M: Isn't jitter amplified?
  - Fangyi: We assume a linear, noiseless, and passive channel
    - Device noise must be translated to jitter somehow
- slide 10:
  - Fangyi: The TX and RX halves are in the same IBIS file
    - They have separate AMI and DLL files
  - Bob: Should the Model_type indicate they are redrivers?
  - Michael M: This gives no indication the RX feeds to the TX
  - Fangyi: We are open to suggestions about that
  - Todd: Walter proposed a means for that some time ago
  - Fangyi: There is no conflict with Walter's proposal

  - Ambrish: We should support non-AMI redrivers too
  - Fangyi: This BIRD assumes AMI
  - Walter: My [Repeater Pins] keyword could be [Buffer Pins]
    - It would be a retimer or redriver depending on whether there is
      an AMI model, and whether it returns clock_times
  - Ambrish: We need to go into the flow of how that works
  - Radek: As written it is only valid for AMI simulations
  - Bob: All of the analog effects are handled in the DLL
    - The TX part would drive the downstream channel
  - Fangyi: But it is pure analog, not event driven
  - Michael M: The only parallel we have is [Series MOSFET]

Arpad: What needs to be done to these BIRDs 131 and 158?
- Ambrish: There should be no problem merging them
- Fangyi: I would prefer to keep them separate
- Bob: Should we vote one down?
- Ambrish: We can't vote down 131
- Walter: I will create a new BIRD to propose the pin keywords

AR: Walter write new BIRD for repeater/retimer pin keywords

Next meeting: 19 Mar 2013 12:00pm PT

Next agenda:
1) Task list item discussions

IBIS Interconnect SPICE Wish List:

1) Simulator directives

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