IBIS Macromodel Task Group

Meeting date: 15 March 2011

Members (asterisk for those attending):
Agilent:                    * Fangyi Rao
                            * Radek Biernacki
Ansoft:                       Chris Herrick
                              Danil Kirsanov
Ansys:                      * Samuel Mertens
                              Dan Dvorscak
                              Deepak Ramaswamy
                              Jianhua Gu
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
Celsionix:                    Kellee Crisafulli
Cisco Systems:              * Mike LaBonte
                              Stephen Scearce
			      Ashwin Vasudevan
Ericsson:                   * Anders Ekholm
IBM:                          Greg Edlund
Intel:                        Michael Mirmak
LSI Logic:                    Wenyi Jin
Mentor Graphics:            * John Angulo
                              Vladimir Dmitriev-Zdorov
                              Zhen Mu
                            * Arpad Muranyi
Micron Technology:            Randy Wolff
Nokia-Siemens Networks:       Eckhard Lenski
Sigrity:                      Brad Brim
                              Kumar Keshavan
                            * Ken Willis
SiSoft:                     * Walter Katz
                              Mike Steinberger
                              Todd Westerhoff
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

The meeting was lead by Arpad Muranyi

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Opens:

- Arpad: Ken has a new item for the agenda

- Arpad welcome guest Marcus Van Iersell

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Call for patent disclosure:

- None

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Review of ARs:

- Bob check BIRD 127 for type clarification possibilities
  - In progress

- Bob write a BIRD on correcting Table 1-3 in the spec.  (Row 23).
  - In progress

- Ambrish draft update BIRD for Table syntax

- Arpad draft BIRD language for block size changes

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New Discussion:

Crosstalk BIRD:
- Arpad: A vote today was suggested last week
- Arpad showed the BIRD
- Radek:
  - On page 2 "The first column of the impulse matrix ..." is not right
    - It is not the primary channel, it is all through channels
  - Next paragraph "This implies ... written into the impulse matrix ..."
    - This is not right
- Arpad: We should not vote today
- Ken: There is nothing technically incorrect

AR: Radek start email thread about Crosstalk BIRD issues

GetWave block size:
- Arpad showed the task list notes:
- Item 8 "GetWave block size"
  - Now clarifies that segments need not be equally sized
- Ambrish: I emailed privately last week on item 5 (Format Table)
- Arpad: I will comment on that

AR: Arpad submit BIRD 120 with new changes to the Open Forum

Proposed Crosstalk BIRD changes:
- Arpad showed a presentation from Snowbush and Sigrity
- Ken:
  - Marcus developed an industry first AMI model with back-channel modeling
  - Have discovered what needs to change in AMI for back-channel
  - Back-channel is real time adaptive
  - Must be implemented in GetWave
  - Modifications:
    - Parameters both in and out
    - New reserved parameters
    - New back-channel .ami file format
    - Flow changes
- Arpad: Is the new .ami file just additional
- Ken: It is only for new data
- Ken:
  - New reserved parameters
    - TrainEnable: on/off
    - Train: points to new .ami file
    - Frame: describes training bit stream
    - Max_Train_Bits: Max duration
    - BackChanControls: TX <-> RX variables
  - Back-channel AMI file follows AMI format
  - Has Reserved Parameters section
- Scott: What seed is used for PRBS?
  - What sequence is used for PRBS taps?
- Kumar: It depends on the standard
  - Another keyword may be required for LFSR
- Ken: Maybe it should be under Data
- Marcus: Naming the standard should eliminate the ambiguity
- Fangyi: The Usage in Info
  - Can models use this?
- Kumar: The model has to point to the file anyway
  - It will have the information
- Fangyi: The file name is input to the model?
- Kumar: Right
  - The EDA tool will only need part of it
- Marcus: The parameter structure could be any AMI syntax
- Fangyi: The EDA tool has to understand which params?
- Marcus: The BC* back-channel controls
- Kumar: The model has to know the entire standard
- Ambrish: Fangyi wants to know if changing to Info will break it
- Kumar: It won't break it
- Marcus: Specifying the LFSR seed leaves nothing to the imagination
- Arpad: It might be useful for overlaying
- Ken: New BackChanControls section added
- Marcus: This is a 3 tap control
  - It is implementation specific
  - 0, 1, -1 have meaning about tap saturation
  - Flow chart (page 11) shows TX and RX actions and decisions
- Scott: What would be the back-channel flow with crosstalk present?
  - You could have a switch working during adaptation
- Kumar: Crosstalk will corrupt the training pattern
- Marcus: Only if it is correlated
- Kumar: This is why the EDA tool generates the pattern
- Arpad: So crosstalk is evaluated at each iteration?
- Fangyi: Will crosstalk be evaluated simultaneously?
  - What if one channel is done training and not the other?
- Marcus: Not a problem if the EDA tool knows what to do
- Arpad: From where does the TX get the pattern for training?
- Marcus: From the EDA tool
- Arpad: So TX has to tell the tool when it is ready?
- Kumar: IEEE gives the length of the pattern
  - The RX tells the tool when training is done
- Marcus: The only TX GetWave change is modifying EQ based on parameters
- Arpad: TX would have to remember the whole pattern
- Kumar: The pattern has to be resent
- Arpad: How will the tool know when to do that?
- Walter: PRBS is infinitely long
  - Can only change tap coefficients on each GetWave call
  - How to tell tool how many bits to send
- Marcus: 1000 bits should not be a problem
- Walter: IP works with multiple standards
  - Will TX work with different RX protocols?
- Marcus: TX and RX have to work together
  - IBIS would have to standardize this
- Ken: We should keep back-channel discussions on the ibis-atm reflector
  - We should hash it out in these meetings before going to open forum
  - The presentation is on the ATM web page
- Scott: This defines a GetWave training state
  - A state diagram would help
- Arpad: Page 11 has something like that
- Marcus: That shows only the training state
- Kumar: When training done it goes seamlessly to normal mode
- Scott: The exercise may show something we missed
- Ambrish: Do we need two ami files?
- Kumar: The TX and RX have to point to the same file
  - It is standard-specific, not model-specific
- Arpad: Should a BIRD be started?
- Ken: We should stick with PowerPoint for a while
- Mike: There are new people on the new ibis-serdes-backchan list
  - It would be good to use both reflectors
- Walter: Some of those people would not want to discuss generic AMI
- Arpad: Agree that we should use both reflectors

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Next meeting: 22 Mar 2011 12:00pm PT

Next agenda:
1) Task list item discussions

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
