IBIS Macromodel Task Group Meeting date: 12 December 2009 Members (asterisk for those attending): Adge Hawes, IBM * Ambrish Varma, Cadence Design Systems Anders Ekholm, Ericsson * Arpad Muranyi, Mentor Graphics Corp. Barry Katz, SiSoft * Bob Ross, Teraspeed Consulting Group Brad Brim, Sigrity Brad Griffin, Cadence Design Systems Chris Herrick, Ansoft Chris McGrath, Synopsys * Danil Kirsanov, Ansoft David Banas, Xilinx Deepak Ramaswany, Ansoft Donald Telian, consultant Doug White, Cisco Systems * Eckhard Lenski, Nokia-Siemens Networks Eckhard Miersch, Sigrity Essaid Bensoudane, ST Microelectronics * Fangyi Rao, Agilent Ganesh Narayanaswamy, ST Micro Gang Kang, Sigrity Hemant Shah, Cadence Design Systems Ian Dodd, consultant Jerry Chuang, Xilinx Joe Abler, IBM * John Angulo, Mentor Graphics John Shields, Mentor Graphics Ken Willis, Cadence Design Systems Kumar Keshavan, Sigrity Lance Wang, Cadence Design Systems Luis Boluna, Cisco Systems Michael Mirmak, Intel Corp. Mike LaBonte, Cisco Systems Mike Steinberger, SiSoft * Mustansir Fanaswalla, Xilinx Patrick O'Halloran, Tiburon Design Automation Paul Fernando, NCSU Pavani Jella, TI Radek Biernacki, Agilent (EESof) * Randy Wolff, Micron Technology Ray Komow, Cadence Design Systems Richard Mellitz, Intel Richard Ward, Texas Instruments Samuel Mertens, Ansoft Sam Chitwood, Sigrity Sanjeev Gupta, Agilent Shangli Wu, Cadence Design Systems Sid Singh, Extreme Networks Stephen Scearce, Cisco Systems Steve Kaufer, Mentor Graphics Steve Pytel, Ansoft Syed Huq, Cisco Systems Syed Sadeghi, ST Micro Ted Mido, Synopsys Terry Jernberg, Cadence Design Systems * Todd Westerhoff, SiSoft Vladimir Dmitriev-Zdorov, Mentor Graphics Vikas Gupta, Xilinx Vuk Borich, Agilent * Walter Katz, SiSoft * Zhen Mu, Mentor Graphics ------------------------------------------------------------------------ Opens: - None -------------------------- Call for patent disclosure: - No one declared a patent. ------------- Review of ARs: - Arpad: Send out list of questions from the last meeting. - Done - Arpad: Write a clarification BIRD to discuss accuracy issues related to the various AMI clock_tick algorithms in an IBIS-AMI DLL - TBD - Todd: Update the BIRD for IBIS S-parameter box based on feedback from discussion - No update - Arpad: Write parameter passing syntax proposal (BIRD draft) for *-AMS models in IBIS that is consistent with the parameter passing syntax of the AMI models - TBD - TBD: Propose a parameter passing syntax for the SPICE - [External ...] also? - TBD - Arpad: Review the documentation (annotation) in the macro libraries. - Deferred until a demand arises or we have nothing else to do ------------- New Discussion: 1) Discussion of questions from the last meeting and Walter's response. Fangyi: typo on document, page 4. Related to 'allowed value'. Walter: let's discuss later. Walter showed his responses to the 9 questions emailed on the reflector. 1. Walter: defined the Rx_Clock_Recovery_Mean. It replaces Rx_Clock_PDF. Many models specify clock distribution with parameters dependent on process corner. This effect needed to be described better. Along with Rx_Clock_Recovery_Rj, it describes a normal distribution (mean and sigma) of the clock recovery circuit. Fangyi: sees people ask for other distributions besides gaussian. - Walter: these new values can be returned by the model. What are the other distributions? - Fangyi: Rx DCD that can be appproximated by a dual-dirac. - Walter: we should create other reserved parameters for this. Bob: does this break anything? - Walter: we don't know of any models using the Rx_Clock_PDF. - Arpad: we should ask over the email reflector if we want to know of anyone using the Rx_Clock_PDF parameter. 2/3. Walter: we have a problem if parameters are put in Model_Specific if they later are changed in the spec to be Reserved_Parameters. It would be better to get rid of the labeling. - Bob: might have been some benefits to this structure. Might be a way to keep backwards compatibility. 4. Walter: the Description keyword can be optional throughout. 5. Walter: wants to ignore Format, not drop it. Format violates the basic principle of parameter trees. - Fangyi pointed Walter to page 4 again. - Walter added 'Allowed Values: (Required) and has to be one of the following:" as a description of what is replacing Format. - Bob did not think that Format should be dropped. This is a fundamental architecture issue. This will be brought up later for more discussion and possible vote. 6. Walter: would like to deprecate Tx_Jitter and replace with Tx_Dj and Tx_Rj. - Fangyi mentioned that there should also be other jitter distributions added. 7. Walter: if IC vendor handles jitter in Tx model without GetWave, then you let Tx_Init take care of it. 8. Walter: clarified that a list is a list of things of 'Type'. 9. Walter: a list no longer contains typ. For a list, the default value is the first value if a default is not specified. 2) Discuss Walter's AMI BIRD Draft Walter: we need to get answers to fundamental questions of Format, Tx_Jitter, etc. Can we really get rid of these or not? No point in working on the draft until these are decided. Ambrish: will be be getting rid of tables? - Walter: yes if we get rid of the parameters using tables. - Ambrish: why not add new distributions to Tx_Jitter? - Walter: no means of adding corner to Tx_Jitter. Arpad to Bob: how do you propose getting answers to these questions? - Bob: any time something is deleted, he wants to know why and what other options there are. - Arpad: would like to see a clean spec, but how do we find out if something we remove is actually needed? - Bob: it is a fundamental shift in IBIS to remove anything from the spec, versus just noting that things are not desired. - Walter: asked Arpad to put this info into an email to the reflector explaining that we will discuss these important topics in the next meeting. - Arpad: asked Walter to send him a private email clarifying two questions to be posted on the reflector. - Walter: will send to Arpad and Bob to refine before posting. 3) Discuss final flow in text form (Section 2 of the AMI BIRD draft) No discussion. AR: Arpad to write email to reflector noting these two questions to discuss and vote on next meeting. 1. Do we deprecate or require Reserved_Parameters and Model_Specific descriptions? 2. Do we make Format optional? Next meeting: 15 Dec 2009 12:00pm PT -------- IBIS Interconnect SPICE Wish List: 1) Simulator directives