[ibis-macro] Minutes from the 24 oct 2006 ibis-atm meeting
- From: "Doug White \(dowhite\)" <dowhite@xxxxxxxxx>
- To: <ibis-macro@xxxxxxxxxxxxx>
- Date: Tue, 31 Oct 2006 10:25:13 -0500
Thanks Mike Labonte for your help with the minutes this time.
Doug
IBIS Macromodel Task Group
Meeting date: 24 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
-------------
New Discussion:
Time zones: we will keep meeting at the same time (12:00p PT) after the
US time zone change.
VHPI
We need to discuss this more before we define a new API.
Arpad showed a presentation: "Channel Analysis Flow with IBIS"
There are 2 ways to get a pulse response, characterize the channel and
convolve, or run a plain analog simulation with drivers and receivers.
Arpad explained his view of Kumar's optimization process.
All simulated impulses are really ramps, although very short.
Convolution can be done in AMI_Init.
Some simulators will process the actual waveform in AMI_GetWave to initialize
filter coefficients.
Walter: there are actually 4 steps. Both TX and RX have init functions.
1 call TX init with channel and TX params
2 call TX AMI_GetWave with stimulus pattern, generates V(RX)
3 call RX AMI_Init to setup RX for tap coeffs
4 call RX AMI_GetWave
Optimizer algorithm needs access to model parameters.
Special optimization features for ICM models would be good.
Should be able to use *-AMS API for waveform exchanges.
Walter: won't work for time domain simulators because it requires waveforms in
time chunks, not one timestep at a time.
There is no live communication between the SPICE engine and optimization engine.
Walter: receiver might have a Framostat (black box)
Kumar: you could write a wrapper to make the black box mdel work in AMS.
AR: Mike investigate call dropouts. Arpad has been bounced out with busy
signal twice, Michael Mirmak once.
Kumar added 3 or 4 slides to his presentation. Nice diagrams showing
step-by-step operations.
Walter: how will we document in that model how it works?
Kumar: parameters are passed by character string. Waveforms a vector of doubles.
Aprad noted that the optimization of an eye could be accommodated in IBIS with
a small BIRD proposal with:
-range and step definitions (for parameters) added to IBIS spec for
external model and external circuit calls
Question arose about the possibility of the optimization of the passive channel
itself, utilizing interconnect models (ICMs).
In the case of behavioral representations like s-parameters, this becomes
difficult if not impossible.
Arpad reiterated his view that the AMS languages appear to have their own
structures which could accommodate the data
exchange between simulator entities and the prospective models, in the same way
that Cadence's API proposal does, and with
such changes to IBIS as the "step" and "range" additions mentioned above.
Question the group had was whether we wanted the IC vendors to be forced to
generate AMS models? Kumar answered by saying
that his API proposal is meant to be agnostic to IC vendor models. They can be
anything of any complexity but must have
a standard interface to the simulator. He called this "simulator-neutral". It
was asked whether the AMS API could work like
this (have these characteristics).
Kumar presented some more detailed slides of Cadence API proposal.
INIT: send the impulse response to the black box model, as a bunch of vectors.
GETWAVE: Vector waveforms are sent to RX model, which modifies the waveforms.
Sidenote: Impulse response can be obtained by doing: Output pulse/Ideal input
pulse area
It was asked whether we could obtain voltages at intermediate nodes with this
approach.
AR: Kumar to present an elaborated description of the data constructs in the
next meeting.
AR: Mike to post Cadence powerpoint (presented today) on website.
-------------
Next meeting: Tuesday 31 Oct 2006 12:00pm PT
Other related posts:
