[ibis-macro] Minutes from the 3 Apr 2012 ibis-atm meeting
- From: Mike LaBonte <mike@xxxxxxxxxxx>
- To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
- Date: Tue, 3 Apr 2012 20:19:08 -0400
Minutes from the 3 Apr 2012 ibis-atm meeting are attached.
Mike
IBIS Macromodel Task Group
Meeting date: 03 April 2012
Members (asterisk for those attending):
Agilent: * Fangyi Rao
* Radek Biernacki
Altera: * David Banas
Ansys: Samuel Mertens
* Dan Dvorscak
* Curtis Clark
Arrow Electronics: Ian Dodd
Cadence Design Systems: Terry Jernberg
* Ambrish Varma
Feras Al-Hawari
Celsionix: Kellee Crisafulli
Cisco Systems: Ashwin Vasudevan
Syed Huq
Ericsson: Anders Ekholm
IBM: * Greg Edlund
Intel: Michael Mirmak
LSI Logic: Wenyi Jin
Maxim Integrated Products: Mahbubul Bari
Mentor Graphics: John Angulo
Zhen Mu
* Arpad Muranyi
Vladimir Dmitriev-Zdorov
Micron Technology: Randy Wolff
NetLogic Microsystems: Ryan Couts
Nokia-Siemens Networks: * Eckhard Lenski
QLogic Corp. * James Zhou
Sigrity: Brad Brim
Kumar Keshavan
Ken Willis
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
The meeting was lead by Arpad Muranyi
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Opens:
- None
--------------------------
Call for patent disclosure:
- None
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Review of ARs:
- Arpad to write a new revision of BIRD 117 and 118 to generalize references
to parameters in files (.ami or any)
- in progress
- Ambrish update BIRD 145 for pad to pin mapping and other clarifications
- Need to say what it will not solve
- in progress
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New Discussion:
BIRDs 117/118:
- Arpad: An email was sent to the reflector to encourage discussion
- Arpad showed BIRD 117.3
- Arpad: This shows new [Begin Parameter Tree] and [End Parameter Tree] keywords
- Should we allow multiple trees in one keyword?
- Mike: We should be able to allow multiple trees
- Bob: We only allow one entity for each [Define Package Model]
- Arpad: [Define Package Model] defines the name, this is different
- Radek: The singular word "Tree" in the keyword implies only one
- Arpad: We can make it "Trees"
- Fangyi: The rules for this would be different than for AMI
- Arpad: Yes the BNF would be a little different
- The AMI rules are in section 10
- BIRD 127 gives more information
- Bob: Is there a problem with reserved words like Vinh?
- Arpad: There should be no problem
- Bob: It may be impractical to put this in the IBIS file
- The syntax is different yet it would have to follow IBIS rules
- Lines would still be limited to 120 characters
- Parser complexity may be a problem, and we have limited parser funding
- Arpad: The parsing and syntax checking are separate issues
- Mike: The parsing of data in nested parentheses should be separate from
the checking for Reserved_Parameters, etc.
- Walter: We could have a concept of .ibs files being containers of IBIS plus
other file data
- It would go after the [End]
- No TreeRootName would be needed
- Arpad: Then there could be only one tree
- Ambrish: We could give the new keywords name values to be used as virtual
file names
- Arpad: Then the tree name would not be used
AR: Arpad proceed with BIRD 117 change to allow multiple trees
Analog BIRDs 116 & 144:
- Arpad: We should close on the question of if ideal voltage sources are needed
- James: It would be best if we did not define the contents of the models
explicitly
- Arpad: Can we agree that it is sufficient for the specification to define the
ideal sources which drive the Tx model or probe the Rx model?
- Fangyi: I think so
- Bob: D2A converters are needed for any analog interface, and these are ideal
sources
- Arpad: We should be able to specify that these sources must be present at the
interface
- Walter: At the output of the RX we still have an analog signal
- Walter: They are required to know the port order
- Arpad: We have to make it clear that there must be no load at the RX
- Fangyi: Why do we call it an ideal voltage source at the RX?
- It is really a probe
- Arpad: Agree
- Walter: For AMI it is an A2D that outputs a floating point number
AR: Arpad propose IBIS spec changes to clarify ISS D2A & A2D interfaces
- Bob: At some point we can't just edit the BIRD
- Walter: The RX A2D samples at intervals to produce a series of numbers
- Bob: TTL defined an X region between two voltages
- Walter: The IBIS RX output has to always be effectively analog
- A D2A for the TX makes sense
- Arpad: We at least agree the isolation elements are not needed in the
subcircuits
- James: How does the TX D2A handle the range of voltages needed?
- Walter: The voltage swing is defined
- Arpad: This is in the spec
- The TX D2A input uses true/false logic
- James: How is the AMI waveform applied to that input?
- Fangyi: It is convolved with a response
- It can be even a square wave, -0.5V to +0.5V, jittered
BIRD 144.3:
- Arpad: There is a question whether the BIRD remains worthwhile with extra
complications
- Feras: The main change is referring to a Touchstone file instead of SPICE
- The other changes are for port terminations
- The complexity is not much more than A2D and D2A statements
- It forces users to generate correct circuits
- Bob: Calling Touchstone directly makes sense, it should not be banned
- Touchstone is more general, for PDS and coupling applications for example
- IBIS-ISS can serve those needs too
- Port termination is an EDA tool issue, not a model issue
- The tool should be able to figure out the Touchstone file
- I don't support the port termination language
- Arpad: How would the model maker convey how to connect the Touchstone model?
- Bob: That is an EDA tool issue
- Radek: You can't avoid specifying the whole circuit
- Bob: The tool might want to cycle through all possible combinations
- Feras: The tool should not have to guess what to do with extra ports
- Ambrish: Circuits should be provided that completely describe the connections
- We should provide the simplest possible description
- Arpad: Will the model maker know if the D2A is ideal, and a resistor must be
added
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Next meeting: 10 Apr 2012 12:00pm PT
Next agenda:
1) Task list item discussions
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IBIS Interconnect SPICE Wish List:
1) Simulator directives
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