                                             
IBIS Macromodel Task Group

Meeting date: 04 Oct 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:

- Mike noted that he is now affiliated with SiSoft

--------------------------
Call for patent disclosure:

- None

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Review of ARs:

- Arpad ask Radek to propose a methodology
  - Done

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New Discussion:

Arpad: BIRD 140.1 is on the ATM website

Backchannel BIRD:
- Ken was not present

Arpad: BIRD 127.2 was brought back to this committee
- Radek: There are just a few issues
  - The Usage language needs to be more neutral.
- Arpad: It says "optionally" but it is not optional if it
  is a Reserved parameter.
- Bob: Does this shut the door for Model_specific params?
- Radek: It just doesn't matter if they are reserved params
- Bob: Tap params are already reserved
- Bob moved to accept the change made today
  - Curtis seconded
  - The motion passed by acclamation

Arpad scrolled to the pg. 141 changes to the Rx_Clock_PDF example
- Radek: The param is float but the Table contains string labels
- Bob: We made an exception for Labels
  - This is allowed
- Walter: Type should be Integer, UI, Float
- David: Are Labels singular or plural?
  - It doesn't seem to work singular
- Walter: In 5.0 it is plural
- Arpad: Any parser issues like this should be reported
- David: It is a tool issue
- Arpad scrolled to the Tx_Jitter section
  - It says the first column of a Table is a string param name

AR: Arpad look for Table column type issues in BIRD 127.2

Arpad scrolled to the section on Default
- Radek: It needs to also have the exceptions used for AMI_parameters_out

AR: Arpad check on AMI_parameters_out exceptions and maybe send email

Arpad showed the "Clarify sample intervals in IBIS-AMI" BIRD proposal
- Arpad: The specification intends for any sample rate to be supported
  - Enhanced description of impulse_matrix parameter to say more about
    sample spacing
- David: Is it a single matrix, no aggressors?
- Arpad: That is a later change

Arpad: 3.1.2.4 would add more about sample_interval
- Radek: It is not precise to say "data rate" here
- David: We are not making a "must " constraint here
- Fangyi: Should it be a fraction of the bit time?
- David: It should not be any definite requirement
- Walter: It is a fraction of the bit_time
- Fangyi: Do we allow fractions like 64.7?
- Walter: Kumar said we should treat the waveform as continuous
  - sample_interval should at least be a rational fraction of bit_time
  - It is well understood how to convert time intervals
- Fangyi: The DLL will have to convert again on output
  - What if a bit pattern is out of the device range?
- Walter: DLLs can have speed limit checking for bit rates the device
  will not support
- Arpad added that the DLL can report an error for unsupported sample intervals
  - Do we need to change lowest_bit_time?
- Walter: Yes it should be just bit_time

AR: Arpad update BIRD 127

BIRD 140:
- Arpad: This has been posted on the website for weeks
  - The ** section about pg 141 is the trouble
- Bob: "In IBIS-AMI" should be "In IBIS"
  - Format Corner is used and values are 0, 1, 2
- Arpad: This is looking ahead to dependency table
  - The selector is actually hidden from the user
- Radek: That is confusing
  - We use "corner" for different things
- Bob: It is making forward statements
- Arpad: I see no forward statements
- Bob: We have not yet defined Typ/Min/Max for Table yet
- Walter: This can be clarified in the Dependency BIRD
  - No one is confused by this now
- Bob: Agree
  - We can deleted it for this BIRD
- Arpad: We should leave it and pick it up for 5.2
  - We can take it off the plate for 5.1
- Bob motioned to delete paragraph 2
- Fangyi: What are we trying to solve?
- Arpad: It says "align implicitly to slow and fast corners",
  but doesn't define them
- Walter: Maybe it can say "align with IBIS corners"
- Radek: It is a future extension and should be deleted
- Arpad: For the use to select it should be a parameter
  - We should not have two ways to do the same thing
- Radek: If we define it now it will have to be supported forever
- Fangyi: The issue is about how to select, not who selects
  - Because of the C_comp issue we have to make it clear
    what association must not be made
  - The user should know how the data was generated
- Radek: When I need to run Slow I don't know what values to use
- Walter: The IBIS spec makes that clear, but uses different column names
- Fangyi: That is logically clear
  - We need to separate that you end up with different individual values
- Radek: A strict association may not be right
- Arpad: I proposed another solution, with 5 values
  - It allows users to forcibly select min or max in addition to slow and fast
- Fangyi: We do not define them well enough
  - What is the meaning of "min"?
- Arpad explained the "C_comp problem"
- Fangyi: The user chooses a condition, and the model choose the settings
- Bob: The 5 choice proposal is a step backward
  - The biggest problem is just C_comp
  - Slow=max and fast=min works 90% of the time
- Walter: Should we remove the C_comp min < max restriction?
  - Then the fast value could be put in for max, etc.
- Radek: That would make IBIS strictly slow and fast
- Arpad: There is a statement more or less to that effect
- Walter: We could get rid of Typ/Min/Max altogether in this section
- Arpad: IBIS defines corner names
  - In [External Model] we have a definition of corners
- Fangyi: Does the spec define how model makers set the values?
- Arpad: It is in section 9
  - It says params like C_comp do not correlate to I-V and V-T curves
  - It is then unknown which values to use for fast or slow
- Fangyi: At least it is clear when we say we are not solving a problem
  - It is confusing when we do not solve a problem and don't say it
  - Can we explain the meaning in section 9?
- Arpad: The meanings are already described in section 9
- Fangyi: It doesn't say slow and fast
- Arpad: It says high/low voltage and strong/weak
- Fangyi: Why does Format Corner have 3 values in one place and 5 in another?
- Arpad: If it is only 3 slow and fast have to be decoded from min and max
- Walter: There would have to be a 6th "Typ" value
  - The "Typ" corner might actually require the min value
- Arpad: Added a 3rd proposal with Typ/Min/Max_performance labels

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Minutes by Mike LaBonte
Next meeting: 11 Oct 2011 12:00pm PT

Next agenda:
1) Task list item discussions

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
