[ibis-macro] Minutes from October 2011 ibis-atm meetings
- From: Mike LaBonte <mike@xxxxxxxxxxx>
- To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
- Date: Fri, 14 Oct 2011 12:03:08 -0400
Minutes from October 2011 ibis-atm meetings are attached.
Mike
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
------------------------------------------------------------------------
Opens:
- Mike noted that he is now affiliated with SiSoft
--------------------------
Call for patent disclosure:
- None
-------------
Review of ARs:
- Arpad ask Radek to propose a methodology
- Done
-------------
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
-------------
Minutes by Mike LaBonte
Next meeting: 13 Oct 2011 12:00pm PT
Next agenda:
1) Task list item discussions
-------------
IBIS Interconnect SPICE Wish List:
1) Simulator directives
IBIS Macromodel Task Group
Meeting date: 11 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
------------------------------------------------------------------------
Opens:
- None
--------------------------
Call for patent disclosure:
- None
-------------
Review of ARs:
- Arpad look for Table column type issues in BIRD 127.2
- Done
- Arpad check on AMI_parameters_out exceptions and maybe send email
- Done
- Arpad update BIRD 127
- Done
AR: Mike check on posting of BIRD 127.3 draft
-------------
New Discussion:
Backchannel BIRD:
- Ken: It has not been changed for a while
- We need to finalize any remaining issues
- Arpad showed the BIRD draft
- Ken: We should move crosstalk issues into a separate BIRD
- Walter: This should be submitted to the Open Forum to get a BIRD number
- Vendors can check for compliance and deal with problems as found
- We should have done this for AMI 4 years ago
- There is no rush to get approval
- Ken: No issue with that
- Bob: That is a misuse of the BIRD process
- It would have zero status
- Walter: It would be under revision control
- People would know they do it at their own risk
- Ken: The only reason not to submit is if there is a known flaw
- We know of none now
- Bob: The rules for pattern definition are not well defined
Arpad showed BIRD 127.3:
- Arpad: This calls for Type to have multiple values
- Some notes have been removed to avoid confusion
- Added a reference to section 3.1.2.7 because we separated
AMI_parameters in and AMI_parameters_out
- Added explanation of AMI_parameters_out string formation
- This needs to be reviewed
- Walter: It looks fine but needs study
- The parser should check for multiple Type values if version is 5.1
- Even a list of values is a single value if between one set of parentheses
- Arpad: This is not a technical issue
- Bob: We should add note 9 on page 6
- Description is optional but it might be construed as required here
Arpad showed SamplingRateBIRD_03.txt:
- Arpad: Sample rate is discussed in three places
- The sample_interval parameter is introduced
- Walter: Some models only work at certain block sizes
- We should have the same wording for that
- Arpad: Should that be an independent BIRD?
- Mike: They are somewhat related
- The sample_interval factors into the number of samples sent to Getwave
- Arpad: We will postpone this to another meeting
BIRD 123:
- Arpad: It should be bumped up to a different number
- Walter: It will 123.5 rev locally, submitted to Open Forum as 123.3
Corner issues:
- Walter: IBIS has a good definition of slow/weak and fast/strong.
- It does not require tools to use them
- AMI corners match the defined derivation methods
- Typ is the 1st value, slow 2nd, fast 3rd
- Walter showed his recent email on the subject
- Walter: The term "it is permissible" in section 9 should be changed
- Anything that is Format Corner has to do with the derivation method
- Arpad: What about C_comp?
- Walter: A new C_comp parameter such as Bob's proposal would be valid
- Bob: Agree, but analog models might have C_comp
- Walter: AMI models can not use regular IBIS models
- There are more than 3 corners
- Touchstone can be used
- Arpad: It is still allowed in 5.0
- Walter: It only makes sense with parameterized ISS subcircuits
- Arpad: We need to move on to discussing 5.2
-------------
Minutes by Mike LaBonte
Next meeting: 18 Oct 2011 12:00pm PT
Next agenda:
1) Task list item discussions
-------------
IBIS Interconnect SPICE Wish List:
1) Simulator directives
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