[ibis-macro] Minutes from the 31 oct 2006 ibis-atm meeting

  • From: "Doug White \(dowhite\)" <dowhite@xxxxxxxxx>
  • To: <ibis-macro@xxxxxxxxxxxxx>
  • Date: Mon, 6 Nov 2006 15:49:16 -0500



Doug White

Tech Lead, High Speed Design

Service Provider/Routing Technology Group

Cisco Systems, Inc.

(919) 392-4103


IBIS Macromodel Task Group

Meeting date: 31 oct 2006

Members (asterisk for those attending):
* Arpad Muranyi, Intel Corp.
  Barry Katz, SiSoft
  Bob Ross, Teraspeed Consulting Group
* Doug White, Cisco Systems
* Hemant Shah, Cadence Design Systems
  Ian Dodd, Mentor Graphics
  Joe Abler, IBM
* John Angulo
  John Shields, Mentor Graphics
  Ken Willis, Cadence Design Systems
* Kumar, Cadence Design Systems
  Lance Wang, Cadence Design Systems
  Michael Mirmak, Intel Corp.
* Mike LaBonte, Cisco Systems
  Paul Fernando, NCSU
* Randy Wolff, Micron Technology
* Richard Ward, Texas Instruments
  Sanjeev Gupta, Agilent
  Shangli Wu, Cadence
* Todd Westerhoff, Cisco Systems
* Walter Katz, SiSoft
  Vuk Borich, Agilent
  Vikas Gupta, Xilinx

Review of ARs:

- Michael will try to get access to the IEEE document they are voting on.
  He will check into access restrictions first.  If we get access to
  it, we will need a couple of volunteers to read the document and see if
  it is worth our while.
  - TBD

- Macro Library Documentation
  - Mike will get to this in Nov

- Mike posted recent presentations regarding API on the website.

- Mike LaBonte looked into the phone bridge service since several Intel calls 
have been dropped. The MeetMe service used has been   flagged for phaseout, so 
Mike did not pursue support. We can switch over to using the MeetingPlace 
service, which combines audio   and web sharing, using only the audio portion. 
No immediate change planned.  If there are more drops, then we can switch over 
at   that time.

New Discussion:

Continued discussion of Kumar's presentation
Slide 7:
- In the top portion the driver and receiver have to operate in the same 
simulator - analog/electrical/circuit model.
- Bottom portion shows the algorithm model, implemented as executable code.
- Walter: what are the inputs and outputs of the Rx model?
  Kumar: both Tx and Rx contain only the "front end". inseparable from the 
     Init() takes impulse respone V/T, char string parameters
- Questions from Walter to Kumar:
  Q: what does the Rx Init() function return?
  A: It may pass back it's dataspace, or just pass/fail.
  Q: Can it return peaking filters?
  A: Not included in this proposal but yes, it can return anything.
  Q: Do not have to write software to use an IBIS model. This proposal would 
need new software for each model.
  A: ???
  Q: What are input and output of GetWave()?
  A: Output can be CDR output waveform and list of clock ticks. Bit time 
contained in clock ticks.
- Walter will find out if this system is sufficient for his simulator, and how 
difficult it will be to build models.
- Arpad: What generates the "actual waveform" passed to getWave()?
  Pulse response convolved with stimulus to produce it.
- Arrows from top to bottom should be down only
- Arrow from pulse to orange Tx should go left only
- Arrow from waveform to green Rx should be right only
- Key point about this architecture:  Algorithmic modeling is completely 
separate from the circuit-level modeling...there is no
  feedback from one to the other.
Slide 15 shows sequence of operations.
- Waveforms 2 and 3 are identical
- Waveform 1 is not Init wave, it is returned from Rx (unusual case)
Bit pattern may be pure 1/0, or have have been convolved already.
Mike: Simulator has to know how to handle everything given it. It has to be 
plug and play, or it's not IBIS.
Arpad: will one model contain both the top and bottom parts (e.g. AMS model)?
- Kumar: Lower-left box not needed if upper-left contains both algorithm and 
- Walter: 10,000 bits will simulate slowly in this case.
- Arpad: For SerDes analysis bottom-left and bottom-right boxes have to be very 
- Kumar: alternative is to characterize impulse response for all possible tap 
  - Arpad: How will driver know what coefficients to use?
Arpad:  It is likely that AMS models will be created, but the fact that AMS 
models will include both algorithmic and circuit
portions makes it difficult to understand how the API will handle this.
Kumar:  If the circuit-level behavior can be clearly delineated from 
algorithmic behavior, then API should handle.
Walter: need clear definition of Tx/Rx ins and outs to Init() and GetWave() 
functions, including how to pass parameters.
Arpad: will help us figure out what IBIS needs to specify
Mike: will allow EDA vendors to develop parameter GUI
Walter can check compatibility with his system once he knows I/O conventions.  
Also will begin invesigating how difficult it may
be to build these types of models.
Arpad: we need to be clear about types of waveforms and not just say 
"waveform". Need specific labels.  
Arpad:  Does the driver wiggle it's outputs in order to generate the impulse 
  -Kumar seemed to imply that the COULD be a way to generate the impulse 

AR:  Kumar will go through a tutorial example of this whole process.  Arpad 
asks that it be very clear with respect to terminology,
such as exactly what the "waveforms" are, how they are generated, what is being 


Next meeting: Tuesday 7 Nov 2006 12:00pm PT

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