[ibis-macro] Minutes from August ibis-atm meetings

  • From: Mike LaBonte <mike@xxxxxxxxxxx>
  • To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
  • Date: Tue, 28 Aug 2012 16:20:56 -0400

Minutes from August ibis-atm meetings are attached.

Mike
                                             
IBIS Macromodel Task Group

Meeting date: 07 Aug 2012

Members (asterisk for those attending):
Agilent:                    * Fangyi Rao
                            * Radek Biernacki
Altera:                       David Banas
                              Julia Liu
                              Hazlina Ramly
Andrew Joy Consulting:        Andy Joy
Ansys:                        Samuel Mertens
                            * Dan Dvorscak
                            * Curtis Clark
                              Steve Pytel
Arrow Electronics:            Ian Dodd
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
                              Feras Al-Hawari
Cavium Networks:              Johann Nittmann
Celsionix:                    Kellee Crisafulli
Cisco Systems:                Ashwin Vasudevan
                              Syed Huq
Ericsson:                     Anders Ekholm
IBM:                          Greg Edlund
Intel:                      * Michael Mirmak
Maxim Integrated Products:    Mahbubul Bari
Mentor Graphics:            * John Angulo
                              Zhen Mu
                            * Arpad Muranyi
                              Vladimir Dmitriev-Zdorov
Micron Technology:          * Randy Wolff
                            * Justin Butterfield
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
                            * Ray Anderson

The meeting was led by Arpad Muranyi

------------------------------------------------------------------------
Opens:

- Mike: Having trouble with eda.org email reflector
  - Please send email to ibis-macro@xxxxxxxxxxxxx, ibis

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

- None

-------------
Review of ARs:

- Arpad prepare example BIRD 125 IBIS file set
  - not done

- Bob to propose a simpler way for addressing the needs of parameter passing
  under [External Model] and [External Circuit]
 - not done

-------------
New Discussion:

Walter showed a presentation "IBIS-ISS Package Modeling":
- slide 1 to 3 are overview slides
- slide 4:
  - Walter: Aggressor channels may be less accurate than victim, but must model 
crosstalk well
- slide 5:
  - Walter: Drivers are on the same chip for FEXT
- slide 6:
  - Walter: Banks imply associations between groups of buffers
- slide 7:
  - Walter: The syntax used here is mostly to highlight the required 
functionality
    - Some materials are from vendors who can not be named, some can
- slide 8:
  - Walter: Voltage supplies can have one name but multiple nodes
    - May need to support resistors in package
    - There is some redistribution of power and ground pin to pin
    - [Pin Mapping] may have some overlap, need to investigate
    - Alternative is to add Pullup_Signal_Name and Pulldown_Signal_Name
  - Arpad: It may be wise to stay away from [Pin Mapping] for new package syntax
  - Walter: That may be a rat hole
- slide 9:
  - Walter: Cdie and Rdie may not represent the interconnect complexity well 
enough
- slide 10:
  - Walter: This shows how the syntax might work together
- Slide 11:
  - Walter: Die names here could be called "implicit"
    - X and Y coordinates are added to support MCP
    - Not fully advocating this feature
  - Fangyi: What are the units?
  - Walter: It is given here as "inch", but it could be microns for silicon
- slide 12:
  - Walter: Supply die data are given separately here
    - These are explicit die names
- slide 14:
  - Walter: Both implicit and explicit die names are used here
    - On-die models are assigned by name
    - Ports are listed in the order they appear in ISS
- slide 15:
  - Walter: The package model example here passes Length in as a parameter
- slide 16:
  - Walter: Pin names here are the high pins of diff pairs
    - This should cover 99% of package usage
- slide 17:
  - Walter: This should handle 90% of package model cases
- slide 18:
  - Walter: VDD and VSS are used to denote associated supplies
- slide 19:
  - Walter: Not sure if this section about resistors is correct yet
- slide 20:
  - Walter: This has 2 DQ aggressors and 1 DQS aggressor
    - The model name for the NEXT aggressor is given
    - DDR3 models tend to give values from standards, not what the part does
  - Fangyi: Is this saying where crosstalk is coming from?
  - Walter: The industry requires the aggressor and victim models to be the same
- slide 21:
  - Walter: Some vendors want to supply more than 3 corners
    - This uses the {squiggly bracket} substitution syntax
- slide 22:
  - Walter: It would be convenient to just use a Touchstone file, if that is 
all that is needed
- slide 23:
  - Walter: Some models will describe a whole interface
    - Some terminals may not be correct in this example
- slide 23:
  - Walter: Some models will describe a whole package
    - NC is used to leave some ports unconnected
    - Reduced s-param models can be derived from larger ones
- slide 24:
  - Walter: They should be organized by sij instead of frequency to make it 
easier
- slide 25:
  - Walter: A Perl script can produce the derived parameter syntax
- slide 27:
  - Walter: Everything for package models can be used for on-die models
- slide 28:
  - Walter: There are a few errors in this example
- Slides 29 & 30:
  - Walter: These show an example for banks
    - Any number of voltage supplies can be passed in
- slide 31:
  - Walter: I have tried to cover everything that others have requested
    - Is anything else required?
    - Do we need all that is here?

- James: All signals are point to point, that should be a category
  - People want to see coordinates because we get power models with just one 
node name for all
  - Need to regroup into different quadrants
- Walter: A connection could have just one supply name and several bumps
- James: Are the victim features a superset of the aggressor features?
- Walter: Correct
- Arpad: Are the different examples using the same syntax?
- Walter: An interface model is different
  - Only the victim channel is valid
  - Only that one has all the crosstalk modeled
  - Aggressors only generate noise
  - The syntax for them is different
  - The port order has "Pin" and "Pad" notation, for example
  - For interface models have actual pin and bump numbers
  - In interface models everyone is both victim and aggressor

- Fangyi: In victim models you need to say which channel is valid
- Walter: The ones with reserved names are the victims
- Fangyi: We should be able to quickly identify which models are aggressor
- Walter: That is a constraint of the person generating the subckt
- Fangyi: Why specify aggressors?
- Walter: They appear at a certain point in the subckt port order
  - There may be better ways to give this information
- Arpad: This should be done in a more general way
- Fangyi: You may want to analyze only 1 of 100 channels, and only a few 
neighbors matter
- Walter: We need to know the pin and pad of each victim and aggressor
- James: Pad is on the die side?
- Walter: Pin is pin name and pad is bump pad
  - We need a consistent naming convention

- Arpad: Using the P side of diff pairs only works if names are sequential
- Walter: The [Diff Pin] section gives the other side

-------------
Next meeting: 14 Aug 2012 12:00pm PT

Next agenda:
1) Task list item discussions

-------------
IBIS Interconnect SPICE Wish List:

1) Simulator directives
                                             
IBIS Macromodel Task Group

Meeting date: 14 Aug 2012

Members (asterisk for those attending):
Agilent:                      Fangyi Rao
                            * Radek Biernacki
Altera:                     * David Banas
                              Julia Liu
                              Hazlina Ramly
Andrew Joy Consulting:        Andy Joy
Ansys:                        Samuel Mertens
                            * Dan Dvorscak
                            * Curtis Clark
                              Steve Pytel
Arrow Electronics:            Ian Dodd
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
                              Feras Al-Hawari
Cavium Networks:              Johann Nittmann
Celsionix:                    Kellee Crisafulli
Cisco Systems:                Ashwin Vasudevan
                              Syed Huq
Ericsson:                     Anders Ekholm
IBM:                        * Greg Edlund
Intel:                        Michael Mirmak
Maxim Integrated Products:    Mahbubul Bari
Mentor Graphics:            * John Angulo
                              Zhen Mu
                            * Arpad Muranyi
                              Vladimir Dmitriev-Zdorov
Micron Technology:          * Randy Wolff
                            * Justin Butterfield
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
                              Ray Anderson

The meeting was led by Arpad Muranyi

------------------------------------------------------------------------
Opens:

- None

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

- None

-------------
Review of ARs:

- Arpad prepare example BIRD 125 IBIS file set
  - not done

- Bob to propose a simpler way for addressing the needs of parameter passing
  under [External Model] and [External Circuit]
  - not done

-------------
New Discussion:

Walter showed a presentation "IBIS-ISS Package Modeling Discussion":
- This is already on the web site
- slide 2:
  - Walter: Would like to have open discussion, hoping to answer questions today
- slide 3:
  - Walter: Do we need supply voltages?
    - Do we need XY coordinates?
    - The NEXT/FEXT discussion was confusing, there is a better way to describe 
this
- slide 4:
  - Walter: What voltage should be applied to the package pin?
  - Bob: IBIS already addresses this
    - It is specified at the model
  - Randy: [Pin Mapping] specifies this
  - Walter: Two models could be connected to VDD with different voltages
- slide 5 & 6:
  - Walter: XY is more reliable than CAD net name or pin number
    - Coordinates help generate package and die models, but are not needed in 
them
  - Arpad: IC vendors should know what the die and package look like by the 
time they have IBIS
- slide 7:
  - Walter: Someone said [Pin Mapping] should not be used
    - This proposal is to give power and ground signal names in the models
  - Arpad: BIRD 145 is similar
- slide 8 & 9:
  - Walter: A hierarchical numbered port description scheme is better than 
positional port names
    - This distinguishes between pins and pads
- slide 10:
  - Walter: Here is an example using model names and polarity
    - I will post corrections to this slide
- slide 12:
  - Walter: Multi-channel coupling can be described with Channel and Victim 
parameters
    - Supply names like VDD are given here too
  - Radek: Does this give the model name like the [Component]?
  - Walter: No this is a package model
- slide 13:
  - Walter: This format can be use to specify sparse ports to extract from an 
s1000p
- Walter: We can have questions here

- James: How do we map pin to die pad?
  - Power pins map many to many
- Walter showed a [Pin Die Data] example from his previous presentation
- Walter: This shows how implicit die pad names allow for that mapping
- James: Does this work for power?
- Walter: Many old IBIS files have NA for all power pins
  - The [Supply Die Data] slide shows many to many mapping
- Walter showed the Rambus example to explain further

- Ambrish: Could smaller channels make more use of the crosstalk info?
- Walter: Package models are made by interface, quadrant, bank, whole package 
etc.
  - No one simulates the whole package
- Ambrish: In IBIS we mostly care about channels
- Walter: We must decide what needs this satisfies and which to support

- Randy: Is there a way to handle multi-die?
  - This is badly needed
- Walter: That is the next step, we can modify EBD
  - I proposed EMD a few years ago, it should be easy to add the new features 
to EBD

- Greg: The intention is to support existing and new models?
- Walter: Existing IBIS does not have IBIS-ISS
- Greg: It seems this is about helping to extract from boards
- Walter: This is not about that

- Walter: There may be too much functionality listed here
  - Next we must decide how to proceed
  - BIRDs 125 and 145 may or may not have all that is needed
  - My approach is model based, not pin based
  - A model can give data that applies to many pins
  - In BIRD 125 the on-die model calls the buffer models
  - Here the die is just between the existing models
- James: More details would be needed to compare this to Arpad's proposal
- Walter: Yes, much work is needed once we choose a path
- James: It needs to be organized so models from different companies/divisions 
can work
- Walter: The interfaces are all by pin/model/die names

- Arpad: Do we need to decide syntax or functionality
- Walter: Functionality
  - The syntax could be keyword or parameter trees
  - Parameter trees can be very powerful
- Arpad: BIRD 125 could be extended to cover all of this
  - So syntax is the only difference
  - The questions are about large s-params, XY coordinates, voltages
- Walter: I have been unable to see how to extend BIRD 125
- Arpad: The question is if we need all this functionality
- Walter: We could vote feature by feature next week
- Arpad: One general purpose syntax might satisfy all of them
  - Questions could be whether we want RC circuits, LC circuits, etc.
  - We do not need to choose because IBIS-ISS can do all of them
- Ambrish: It would be good to have the voting list emailed in advance

AR: Walter email a list of package modeling features for voting

-------------
Next meeting: 21 Aug 2012 12:00pm PT

Next agenda:
1) Task list item discussions

-------------
IBIS Interconnect SPICE Wish List:

1) Simulator directives
                                             
IBIS Macromodel Task Group

Meeting date: 21 Aug 2012

Members (asterisk for those attending):
Agilent:                    * Fangyi Rao
                            * Radek Biernacki
Altera:                       David Banas
                              Julia Liu
                              Hazlina Ramly
Andrew Joy Consulting:      * Andy Joy
ANSYS:                        Samuel Mertens
                            * Dan Dvorscak
                              Curtis Clark
                              Steve Pytel
                            * Luis Armenta
Arrow Electronics:            Ian Dodd
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
                              Feras Al-Hawari
Cavium Networks:              Johann Nittmann
Celsionix:                    Kellee Crisafulli
Cisco Systems:                Ashwin Vasudevan
                              Syed Huq
Ericsson:                     Anders Ekholm
IBM:                        * Greg Edlund
Intel:                        Michael Mirmak
Maxim Integrated Products:  * Mahbubul Bari
Mentor Graphics:            * John Angulo
                              Zhen Mu
                            * Arpad Muranyi
                              Vladimir Dmitriev-Zdorov
Micron Technology:            Randy Wolff
                            * Justin Butterfield
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
                              Ray Anderson

The meeting was led by Arpad Muranyi

------------------------------------------------------------------------
Opens:

- Bob: Would like to address IBIS parser issues

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

- None

-------------
Review of ARs:

- Walter email a list of package modeling features for voting
  - Done

- Arpad prepare example BIRD 125 IBIS file set
  - not done

- Bob to propose a simpler way for addressing the needs of parameter passing
  under [External Model] and [External Circuit]
  - not done

-------------
New Discussion:

Bob discussed AMI changes in the new IBIS parser:
- Bob: Initially there was a warning for parameter name collisions
  - It now checks for collisions only within each branch
  - The leaf check for Description has been fixed, allowing only one per branch
- Arpad: This Friday might be the big day for IBIS 5.1

Luis Armenta introduced himself:
- He is working on AMI models at ANSYS

Walter showed a presentation:
- Walter: This presentation has been sent out
  - It summarizes use of parameter trees and IBIS-ISS for various models
- Some slides are brief summaries
- slide 5:
  - Walter: This example explains the proposal for packages
- slide 6:
  - Walter: This tree shows a typical on-die model
    - There are 4 bump pads for power and ground
    - Power and signals could be merged together
- slide 7:
  - Walter: This package model tree looks similar to the on-die one
- slide 8:
  - Walter: This adds length modeling where that is known
- slide 9:
  - Walter: This package tree shows victims and aggressors for crosstalk
- slide 10:
  - Walter: Arpad asked for both package and on-die trees here
    - This makes the model understandable and easy for EDA tools to use
- slide 11:
  - Walter: [Path Description] can be converted programmatically to IBIS-ISS
- slide 12:
  - Walter: Here is a legacy EBD file
    - It has comments to show what things are
  - Arpad: Do the slashes precede comments?
  - Mike: They are for continuation, pipe characters for comments
  - Walter: I may have modified this
- slide 13:
  - Arpad: The red line doesn't say how the IBIS-ISS package is connected
  - Walter: Good point but we will not be pursuing that
- slide 15:
  - Walter: Gd and RS are critical, but EBD doesn't support them
- slide 16:
  - Walter: This replaces a path description
  - James: Is U1 a reference designator?
  - Walter: Yes, this EBD is for a DIMM board
  - Fangyi: Would this work without the pin order?
  - Walter: That could work
- slide 17:
  - Walter: EMD "module" is less constraining than EBD "board"
- slide 18:
  - Walter: This is the legacy EBD converted to EMD
    - The only new thing here is Diff_Pins
- slide 19:
  - Walter: Nothing is different for a connector
    - Defining the A and B sides may not be necessary
    - Vendors often give slice models from which all pins are derived
  - Fangyi: The unconnected pins are assumed to be open?
  - Walter: Or 50 ohms to ground, etc.
    - A typical method is to extract a smaller s4p
  - Fangyi: It still depends on what is assumed for the other ports
  - Walter: They are effectively open
  - Radek: That will not work
  - Arpad: Some models are not symmetric in each direction
  - Walter: The A and B signal names handle that
- slide 20:
  - Walter: Some of our existing BIRDs are gobbledygook
    - There is confusing baggage
- slide 21:
  - Walter: [External IBIS-ISS Model] is a simple way to handle it
    - Stimulus and other items are easily defined in tree format
  - Arpad: Stimulus is what the DtoA converters handle
    - This is a new keyword for something that exists
  - Walter: The Model_Ports syntax is very simple
- slide 22:
  - Walter: We should reject the listed BIRDs and create a new IBIS 6.0 EMD 
section
    - I will make this motion Friday at the Open Forum meeting
- slide 21:
  - Fangyi clarified how the TX Stimulus parameter works with the model ports
  - Walter: IBIS-ISS is invalid for most buffer models because it can't handle 
input and enable
    - PWLs or macros would have to be added, as in IBIS-BSS
    - Model_Ports is similar to Model Connection Protocol
  - James: How to tell which ports are connected to stimulus?
  - Walter: Drive is a reserved name for that
    - We might want to call that Stimulus
    - This attempts to not make too many changes
    - It will be a lot of work to write this BIRD, it should be a group effort
  - Fangyi: Coloring the reserved names may help avoid future questions
  - James asked about the format of the Tstonefile parameter
  - Walter: It goes into the AMI file to get the value
    - Some AMI models have many "knobs", and some change the Tstonefile
  - Radek: The right side model is used only with AMI models?
  - Walter: Values can be directly specified here
- slide 22:
  - Ambrish: This replaces all of the BIRDs proposed for rejection?
  - Walter: Yes, for example the package and on-die models replace [Circuit 
Call]
    - What I'm proposing requires only one new parser

AR: Walter send slides with modifications for posting

Bob: This Friday IBIS 5.1 is the priority
- There may not be much time for other items

-------------
Next meeting: 28 Aug 2012 12:00pm PT

Next agenda:
1) Task list item discussions

-------------
IBIS Interconnect SPICE Wish List:

1) Simulator directives
                                             
IBIS Macromodel Task Group

Meeting date: 28 Aug 2012

Members (asterisk for those attending):
Agilent:                    * Fangyi Rao
                            * Radek Biernacki
Altera:                     * David Banas
                              Julia Liu
                              Hazlina Ramly
Andrew Joy Consulting:        Andy Joy
ANSYS:                        Samuel Mertens
                            * Dan Dvorscak
                            * Curtis Clark
                              Steve Pytel
                              Luis Armenta
Arrow Electronics:            Ian Dodd
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
                              Feras Al-Hawari
Cavium Networks:              Johann Nittmann
Celsionix:                    Kellee Crisafulli
Cisco Systems:                Ashwin Vasudevan
                              Syed Huq
Ericsson:                     Anders Ekholm
IBM:                        * Greg Edlund
Intel:                      * Michael Mirmak
Maxim Integrated Products:    Mahbubul Bari
Mentor Graphics:            * John Angulo
                              Zhen Mu
                            * Arpad Muranyi
                              Vladimir Dmitriev-Zdorov
Micron Technology:            Randy Wolff
                            * Justin Butterfield
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
                              Ray Anderson

The meeting was led by Arpad Muranyi

------------------------------------------------------------------------
Opens:

- Arpad: Should we meet next week, given the labor day holiday?
  - No one said they can not attend
  - We will meet next week?

- Arpad: Should we allow TX and RX of different AMI_Version in the same 
simulation?
  - Walter: This is somewhat academic
    - Only one old model has Use_Init_Output
    - Our tools will have no problem
  - Mike: Models from different vendors might be in the same simulation
  - Arpad: The question is whether to allow it in the specification
  - Radek: The spec already allows an older model to be in a newer IBIS file
  - Arpad: The question is if they should be allowed in the same simulation
  - Radek: We can't restrict that, people will mix models
  - Walter: Certain combinations require deconvolution
    - The math for that is clear, this is not a problem
    - It is a rare case anyway
  - Radek: We could post guidelines outside of the IBIS spec

- Michael M: Thank you to the group for making IBIS 5.1 a reality

- Greg: We should discuss roadmap, especially packaging
  - Arpad: There is an agenda item for that

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

- None

-------------
Review of ARs:

- Walter send slides with modifications for posting
  - Done

- Arpad prepare example BIRD 125 IBIS file set
  - Not done
  - Will do this only if we keep BIRD 125

- Bob to propose a simpler way for addressing the needs of parameter passing
  under [External Model] and [External Circuit]
  - Not done
  - We can drop this

-------------
New Discussion:

Arpad: We need to discuss what is next for our group
- Walter showed a presentation "IBISx"
- slide 2:
  - Walter: Legacy IBIS has everything in one file
    - Package information should be in a separate EMD file
- slides 3 & 4:
  - Walter: Translating an legacy package model to EMD is straightforward
- slide 6:
  - Walter: The die model is similar
- slide 7:
  - Walter: Models also translate easily
- slide 9:
  - Walter: This is the roadmap
    - Some BIRDs should be rejected
    - Some BIRDs that are AMI related would not be rejected, go into 5.2
    - Backchannel BIRDs would be in 5.3
    - We have not seen demand for backchannel modeling
    - New BIRDs for 6.0 will be needed
  - Ambrish: We should make backchannel higher priority
  - Walter: That is OK
    - Gennum has asked for it, but not many users yet
  - Arpad: We should have a new category for analog models
  - Radek: This is an overhaul of the general IBIS syntax
    - Legacy IBIS has no clear hierarchy
    - We need to analyze what we gain and lose

- Greg: Do we maintain backward compatibility?
- Walter: No, this is a new standard
- Bob: I am not in favor of splitting IBIS into different sections
  - IBIS will continue for a while
- Walter: It will continue but we do not have to maintain it
  - I/V curves and other things would be reused, not reinvented
- Arpad: We explored going to equation based models
  - This might be a good time to revisit that
- Walter: Yes, that might be an additional parameter to Legacy and IBIS-BSS
  - Kumar proposed parameter trees years ago, and they are easy to work with
- James: This is mostly about syntax
  - Are we propose any changes to the functional part?
- Walter: Adding a Tstonefile is a functional improvement, for example
- Ambrish: The other proposal is to use IBIS-ISS
- Arpad: This is starting over
  - It might take years to finish this
  - Can a well defined analog model wait that long?
- Walter: I think this can be done in six months
- Arpad: IBIS 5.1 took 4 years
- John: AMI was going to be simple too at the beginning
  - I don't see a difference
- Arpad: It could take quite a while to do equation based models
- Walter: Yes, but I am proposing stuff we already know how to do
  - Originally we made mistakes because we did not understand the problems
  - We have better understanding now of the physics
- Arpad: Writing a specification is not just about physics
  - Getting vendors to agree on details can be difficult
- James: We need to address the question of what problem we are trying to solve
- Walter: IC vendors need to supply broadband package and on-die models
  - For both signals and power delivery
- Arpad: The point is that we don't have to rewrite the syntax for that
- James: We need to analyze how this helps achieve that
- Walter: We still have no example of how to create needed models with the 
existing BIRDs
  - On-die models are independent of package models
- John: Having just a proposed syntax may not help enough
- Michael M: We should have a drawn example, not in the proposed syntax
  - Then see what it takes to create examples
- Walter: Greg said he was willing to supply examples
- Arpad: We could try that
- Walter: IC vendors should report what they can supply and what they want

AR: Greg and Michael M provide examples to show what IC vendors need

Bob: I do not agree with the roadmap slide
- We should not assume that it has been accepted

-------------
Next meeting: 04 Sep 2012 12:00pm PT

Next agenda:
1) Task list item discussions

-------------
IBIS Interconnect SPICE Wish List:

1) Simulator directives

Other related posts: