IBIS Macromodel Task Group

Meeting date: 25 January 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
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: Our next meeting be held Feb 08 given DesignCon next week

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Call for patent disclosure:

- None

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Review of ARs:

- Arpad: Submit Typos BIRD to Open Forum
  - Done, BIRD 127

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New Discussion:

Arpad showed the ATM Update presentation for the summit:
- Slide 2:
  - Bullets for various BIRDs 112 through 127
- Slide 3:
  - Work in progress = analog, dependency table, jitter
- Slide 4:
  - Work ahead = AMI Task List
- Bob: The title slide will have to be checked

AR: Arpad send PDF of presentation to Bob

Arpad showed the AMI Task List:
- Updated today
- Arpad: Biggest change is showing BIRD 127
  - Item 22 is addressed by the Typos BIRD
  - Dual-Dirac might be combined with another
  - Item 35 may be covered by the analog BIRD
  - 46 and 47 are about removing keywords and reserved params
  - Item 18 is not clear
    - What is the ambiguity between Format and text strings?
    - BIRD 127 may cover this
- Bob: I can check on this
- Arpad: Item 21 still has one outstanding issue

AR: Bob check on task list item 18, Format and text strings

Arpad showed the Analog BIRD:
- Arpad: There was some discussion with Scott
- Slide 2:
  - Arpad: The tool will provide the differencing block
  - Ambrish: What stimulus does it require?
  - Arpad: This will work in TD or to create impulse response
    - Params can be passed in from the IBIS file
  - Walter: The ISS it's whats in the box
    - The "1"s are outside the box
  - Scott: The amp must be in the model for it to work everywhere
    - It is an isolation boundary
    - The models must be unambiguous
  - Walter: Then we need a new ISS element
  - Scott: We have a VCVS element
    - We also need the termination the s-param requires
  - Walter: This will have to be acceptable
  - Fangyi: Where does the TX model specify swing?
- Slide 3:
  - Arpad: This slide explains it
    - We need to settle the unity gain requirement
  - Scott: It should say "equivalent" of ideal isolation voltage source
  - Bob: Implies S11 would be infinite instead of zero
  - Fangyi: How the parameters applied?
  - Ambrish: Why not keep the params in the IBIS file instead of AMI?
  - Arpad: This was the easiest way
    - We would have to define new keywords
 - Walter: In the AMI file you can spec strength
   - This determines impedance and voltage range
 - Fangyi: This can't be used for IBIS simulations?
 - Arpad: It has to be in the circuit already
   - The AMI can override what is in the IBIS file
- Slide 2:
  - Arpad: We could just say the PWL stimuli have to be ideal
    - Get rid of the unity gain amp
  - Scott: This moves the boundary into the EDA tool
    - This might cause trouble in Matlab and "home-built" tools
  - Arpad: We should not have to say it is unity gain
  - Scott: Agree
- Slide 4:
  - Arpad: There are questions here
  - 1  EDA tool generate IR
    - Decision: Yes, Yes
  - 2 Analog output to RX GetWave
    - Walter: 
    - Decision: No, No
  - 3 Differential conversion
    - Bob: It is related to rise time
    - Ambrish: It can come from hardware measurements
    - Arpad: The circuit doesn't say how it is to be used
    - Bob: The stimulus would be 1ps
      - s-param already has rise time
    - Arpad: Could a model be made that does not produce the right output?
    - Walter: That would be an illegal model
- Slide 2:
  - Fangyi: How do I know the voltage and slope?
    - It must be looked up in the AMI
    - With IBIS today there is no need to do this
  - Arpad: A non-AMI simulation should not have to do this
    - The IBIS spec has the same for [External Model] and [External Circuit]
  - Fangyi: So it only needs a 1010 bit stream
  - Arpad: Yes

Walter showed Dependency Table BIRD 124:
- The table has independent and dependent parameters

Walter showed BIRD_122-ISS_Subckt.doc
- Walter: I submitted an addition to BIRD 122
  - Adds 3 "ISS" AMI params for file, subckt, and arguments
  - This is all that is needed to use generic ISS
  - This is less text for model makers, less parsing for EDA tools
  - Also has ISS_Subckt reserved values
    - Canned subckts for Touchstone, TX, RX
- Arpad: This is somewhat equivalent to my BIRD
  - This makes it only in the context of AMI simulations
  - My BIRD would work for IBIS simulations too
- Dan: Needs to be looked at, customers care about this
- Walter: We could have both

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Next meeting: 08 Feb 2011 12:00pm PT

Next agenda:
1) BIRD 121-124 discussions

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IBIS Interconnect SPICE Wish List:

1) Simulator directives

