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