IBIS Macromodel Task Group
Meeting date: 01 Nov 2011
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
Celsionix: Kellee Crisafulli
Cisco Systems: Ashwin Vasudevan
Syed Huq
Ericsson: Anders Ekholm
IBM: Greg Edlund
Intel: Michael Mirmak
LSI Logic: Wenyi Jin
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:
- Arpad reviewed the upcoming meeting schedule
- No meeting Nov 15 & 22, Dec 27
- Mike: US DST time shift is Nov 6.
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Call for patent disclosure:
- None
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Review of ARs:
- None
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New Discussion:
BIRD 140:
- Arpad showed version 2 of his "Corner Notes" presentation
- Slide 15:
- What Model_types can be AMI?
- This affects the min/max <> slow/fast mapping issue
- Many typ/min/max keywords are eliminated if Terminator not allowed
- Only [Diff Pin] and [External Model] would remain
- Slide 17:
- Mapping is stated for I-V V-T
- It is sort of stated as a "conservative approach" for C_comp
- Slide 18:
- Define which Model_types are allowed
- Mapping of min/max for Pin[Diff ] [External Model]
- Reiterate for I-V, V-T, C_comp
- BIRD 133 is not needed
- Walter:
- We can assume fast = min for [External Model]
- The faster part should have less skew
-
- Arpad: A Terminator is the same as a receiver, but it has no thresholds
- With AMI we don't do those measurements
- It is hard to see why Terminator is needed for AMI
- S-params would be better than these RLC keywords
- Walter: Several vendors use Terminator and [R Series]
- No objection if we restrict AMI to Input and Output types
- Arpad: Agree
- Bob: Series can be used as diff terminator
- Arpad: This is only because we have pseudo-diff models
- With IBIS-ISS we can have true differential
- Bob: We should not make these types illegal
- Radek: Agree, we should allow them
- Walter: We should not handle typ/min/max for them
- BIRD 120 would do it
- Arpad: We should warn about typ/min/max issues for these
- Bob: No spec statement that Rgnd min < max
- The parser warns though
- That message could be removed
- Radek: We should at least recommend not to use them
- Bob: It would be OK to not have Terminator because that is just a stub
- Radek: We can disallow if we feel strongly about it
- Arpad: There might be a gap between 5.1 and 5.2
- Without IBIS-ISS model makers might have no solution during the gap
- John: Only [Rac] and [Cac] pose a problem
- Bob: We only need a note that Terminator might not be supported in all tools
- Arpad: Can we add the warning text to BIRD 140?
- John: I would rather disallow Terminator and Series models
- Bob: Where does [Algorithmic Model] reside?
- Arpad: in [Model]
- Bob: [Algorithmic Model] does not make sense under Terminator
- Arpad: Actually there can be two models connected to a pin
- single plus series
- Bob: [Algorithmic Model] should be restricted from Series types
- Arpad: Can we exclude AMI from Series types?
- No objection
- Bob: There should be a new BIRD for that
- It does not belong on a corner BIRD
- Bob: [Diff Pin] tdelay* was for statistical use, tolerances
- Arpad: The jitter parameters are better
- Bob: The TT parameter is similar, it only shows how bad your part is
- Walter: Agree with Bob
- Arpad: Should this be addressed in later analog BIRDs?
- Walter and Radek agreed
- No objections
- Radek: It is a good suggestion to clarify for I-V, V-t, C_comp, etc.
- Maybe it should be for IBIS in general, not just AMI
- Arpad: I will rewrite BIRD 140
AR: Arpad rewrite BIRD 140 to disallow AMI Terminator, etc.
Walter showed the jitter BIRD 123.3
- Walter: Draft 2 fixes typos
- Added paragraphs to introduction
- Critical that people review in detail
- Walter read the paragraphs
- Bob: Is this BIRD text or explanation?
- It refers to the BIRD itself
- Walter: That may change in the final version
- Arpad: Will jitter show up in common mode?
- Walter: Getwave inputs are diff, do not account for channel common mode issues
- Skew on the TX would not be modeled correctly
- This is a non-trivial change to Getwave
- Skew under 20% is not an issue
- Don't know of any buffers that bad
- People are worrying about common mode diff coupling
- It is independent of the CDR
- Arpad: Will this be in the spec?
- Walter: The group can decide
- Arpad: This might be useful to explain the jitter parameters
- Bob: It would fit into the analysis section
- Arpad: We should check each jitter description against this
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Minutes by Mike LaBonte
Next meeting: 08 Nov 2011 12:00pm PT
Next agenda:
1) Task list item discussions
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IBIS Interconnect SPICE Wish List:
1) Simulator directives