Minutes from the Nov. 2, 2010 IBIS ATM group meeting are attached. Randy Randy Wolff SI Modeling Manager Signal Integrity R&D Group Micron Technology, Inc. 208-363-1764 <<20101102.txt>>
IBIS Macromodel Task Group Meeting date: 2 November 2010 Members (asterisk for those attending): Agilent: Fangyi Rao * Radek Biernacki Ansoft: Chris Herrick Danil Kirsanov Cadence Design Systems: Terry Jernberg * Ambrish Varma Celsionix: Kellee Crisafulli Cisco Systems: Mike LaBonte Stephen Scearce Ericsson: Anders Ekholm 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 Texas Instruments: * Casey Morrison * Alfred Chong Teraspeed Consulting Group: * Scott McMorrow * Bob Ross Vitesse Semiconductor: Eric Sweetman Xilinx: Mustansir Fanaswalla (NOTE: The list above has been pruned to include only those attending at least one meeting in the past year, and reorganized by company.) The meeting was lead by Arpad Muranyi ------------------------------------------------------------------------ Opens: - Arpad: Set meeting schedule for next two months - November 9 No ATM meeting - Asian Summit (China) - November 16 No ATM meeting - Asian Summit (Japan) - November 23 No meeting due to US Thanksgiving holiday - November 30 Yes - December 7 Yes - December 14 Yes - December 21 Yes - December 27 No meeting - January 4 Yes -------------------------- Call for patent disclosure: - none ------------- Review of ARs: - Arpad update the Typos BIRD draft - say the Typ is the implicit default for all types - Discuss with Walter parameter Default/Value examples - done - Arpad AR from Open Forum on BIRD 114.2: Update BIRD 114.1 to include statements on escape characters in strings, and correct multi-line misinterpretation possibilities - done ------------- New Discussion: Discuss Arpad's Typos_Format_Value_Default BIRD draft http://www.vhdl.org/pub/ibis/macromodel_wip/archive/20101026/arpadmurany i/IBIS-AMI%20Typographical%20Corrections%20BIRD%20draft%204/Typos_Format _Value_Default_BIRD_4.pdf Arpad: Ready for a vote, would like a vote in the next meeting. Any comments? Bob: Where format is 'optional (being deprecated)', remove 'being depractated' since it is optional. Arpad: Remembers being asked to include this text. Ambrish: Supports removing this text. Arpad: Will remove the text. Arpad: Asked Bob to write-up a suggestion for changing one of the notes. Discuss Version BIRD draft http://www.vhdl.org/pub/ibis/macromodel_wip/archive/20101026/walterkatz/ IBIS-AMI%20New%20Reserved%20Parameter%20AMI_Version%20BIRD%20draft%201/V ersion_BIRD_1.pdf Arpad: No comments received so far by email. Walter: Make sure we agree that if an existing IBIS 5.0 model referencing AMI to the IBIS 5.0 definition of AMI, then if we change the IBIS version to 5.1 is it still ok to have the older AMI model satisfying older AMI parsing rules. If the AMI file was legal before, is it still legal? Radek: No decision on that yet. Bob: We should differentiate IBIS 5.1. Can an IBIS 5.1 parser bring in an AMI version 5.0 (without a version number). The parser should be able to. This does make an AMI version required for 5.1 and above. Walter: Intent of BIRD is for IBIS 5.1 models to support both 5.0 and 5.1 AMI models. He doesn't think the BIRD is clear on this intent. Ken: If you update the IBIS file to 5.1, you should update the AMI file to 5.1. Scott: Taking the contrary view. An IBIS file could have multiple models in it. Various models within the file could have features of various versions of IBIS. If no version in AMI file, it should revert to IBIS 5.0 for parsing requirements. He argued that there should be a return parameter from the DLL that identifies its version. This provides an error check. Walter: Make AMI_Version InOut instead of Info. The EDA tool could tell if there is a problem. Ken: Why shouldn't the versions be required to be the same? Walter: This breaks fundamental concepts of IBIS. Discuss BIRD 119 / 121-124 BIRD121: Walter: Comment to change DLLPAth to DLL_Path. Will change DLLid to DLL_ID. Samples_Per_Bit, there are models that require this. Ken: Is there a clash between models if Tx has one and Rx has another? Walter: Calls this situation torque conversion. Must run each model with different samples per bit. Must convert impulse responses, stimulus files and waveforms. BIRD122: Walter: Comments that the template is ok but other templates are needed as well. Described step function generation using the templates. Arrow on Tx model is where the analog and AMI models split. In Rx, Voh and Vol are allowing gain. Arpad: Needs clarification of Tr and Tf on Rx template. Walter: Mistake to add Tr and Tf on Rx template. Arpad: In Tx, does input to triangle have a shape? Walter: All those elements generate step response that is a PWL that goes between Vol and Voh with rise time of Tr, Tf. John: Noted some signs missing in Tx equations. Scott: This is a voltage mode circuit, how do you model a current mode Tx? Walter: model is only for generation of correct step response. Ken: This seems redundant when ISS will be coming into IBIS. Walter: We don't have ISS in IBIS. This is being requested by several companies, because this model comes from their internal tools. Most vendors actually supply a .s4p model Radek: Thinks the .s4p model should be the model supplied. Scott: What is the impedance of the summer? Walter: Thinks this is infinite impedance, direct conversion. Scott: Make sure this is defined. Arpad: Wouldn't the output of the summer driving ports 1 and 3 in the Tx be zero impedance, an ideal driver? Scott: Summer is idealized voltage source with zero impedance. But the S-parameter block has a defined impedance, so this sets up a reflection boundary. S11 needs to be there or you get the wrong response (also S12, S21). Walter: IC vendors are doing it this way already. Scott: This isn't about model makers, this is about writing a correct spec. Walter: Write it up for Mike Steinberger to respond to. Scott: Has already done this. Others on the committee will need to respond as well. Ambrish: Why shouldn't we look at other proposals on the table and choose the best option? Walter: This BIRD will not be changed for other options. BIRDs 116-118 provide another option. Scott: All he asks is that SiSoft provide a technical justification for their methodology. SiSoft is the lead on this BIRD so needs to provide the technical details from the other BIRD sponsors such as Cisco and IBM. Scott: fundamentally there is a loss of energy, so where did it go? Casey: Can't the S-parameter be representing a perfectly terminated system? Scott: Yes, but this isn't perfectly terminated. The authors need to justify this. Arpad: Summer needs to be converted into its electrical equivalent. Ken: Questioning investment in hard-coded subcircuits as opposed to flexible circuits. Walter: The model maker will not give a more specific subcircuit, they will convert that to an S-parameter file Scott: These are Opal parameters. Should these be added in a specific hard coded way or add them in a more general way? Walter: My obligation is to explain this BIRD, but the Open Forum will vote on it. Arpad: This committee should be supplying technical feedback to improve quality of the BIRD. It will be up to the Open Forum to vote on each and every BIRD to decide what is finally supported. This committee can either provide technical assistance to the authors of the BIRDs or let them work on their own and let them submit the BIRDs to the Open Forum for discussion and vote as best as they can. ------------- Next meeting: 30 November 2010 12:00pm PT Next agenda: - BIRD 119 / 121-124 - Any other new BIRDs ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives