IBIS Macromodel Task Group Meeting date: 07 July 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 McGrath, Synopsys David Banas, Xilinx Deepak Ramaswany, Ansoft Donald Telian, consultant Doug White, Cisco Systems * Eckhard Lenski, Nokia-Siemens Networks 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 Comeau, 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 Pytel, Ansoft Syed Huq, Cisco Systems Syed Sadeghi, ST Micro Ted Mido, Synopsys Terry Jernberg, Cadence Design Systems Todd Westerhoff, SiSoft Vladimir Dmitriev-Zdorov Vikas Gupta, Xilinx Vuk Borich, Agilent * Walter Katz, SiSoft Zhen Mu, Cadence Design Systems ------------------------------------------------------------------------ Opens: -------------------------- Call for patent disclosure: - No one declared a patent. ------------- Review of ARs: - Walter clean up IBIS-IS for summit presentation - Done - It will be posted only to the IBIS summit page when ready - Walter has to check with Synopsys on copyright requirements - Arpad write a BIRD to clarify time period accuracy requirements - TBD - Todd: Write IBIS s-param BIRD - Still working on it - 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: Question from the IBIS5 parser developer: "AMI file must have to distinct sections", but one is optional? - Bob: Maybe we will have to make it required even if null - Walter: The BIRD needs clarification - Adding default at the end was a problem - Initially all parameters were mixed together - This was introduced by Cadence - Model_Specific should not be required - Cadence should state what their intent was - Arpad: Making Model_Specific required probably was an accident - Walter: Maybe an empty (Model_Specific) would suffice - Bob: We have to inform the parser developer - We can submit BIRDs to match what we decide AR: Arpad contact Cadence to check on making Model_Specific optional Question from IBIS5 parser developer: "(Format Table (...) does not work" - Walter: Table is info only, becomes academic - Table is not part of the format passed to the DLL - Arpad: That limits us - Walter: The Table keyword has not been used yet - We should get Cadence input on this - They are creating models with non-compliant format - Data vectors could be passed in strings - Arpad showed a way to use a vector format for taps - Walter: We can propose something for 5.1 - Walter: Why is the developer concerned about the BNF? - The BNF describes what the DLL accepts, not the AMI format - He is parsing only the AMI file - Arpad: Doesn't the BNF apply to both? - Arpad: RX_Clock_PDF has a similar non-compliant format - Walter: There may be some problems with the BNF description - Bob: Maybe we should check only the AMI syntax using the BNF - Walter: The BNF is not for the AMI file - The vendor provides 3 things: - IBIS text saying which AMI and DLL files to use - AMI ASCII file - DLL binary file - The allowed value range is given for parameters - The AMI file only tells the tool what the options are - The string passed to the DLL is generated - Mike L: Does this mean the AMI format is unspecified? - Walter: It is specified, but not in BNF - Arpad showed page 143 of the IBIS 5 spec - Mike L: It appears to be given only by a brief example - A typical parser should be easy to write, making assumptions - John: The presence of the BNF is deceptive if it does not apply to .AMI - Walter: The AMI file format has shortcomings: - There is no true/false concept, for example - The wording could be better - Arpad: I can ask Ambrish about this - Mike L: It should be easy to write a generic LISP style parser - It should not have to look at the keywords - Walter: If it doesn't look at the keywords why bother? - Arpad: There appears to be enough info here to write the parser - John: Page 143 paragraph 7: "The model parameter must be ... 3.1.2.6" - Arpad: So what do we tell the developer about "(Format Table"? - Walter: We had decided at one point to drop all Format keywords - Bob: We may have 6 vendors working on this syntax independently - With this specification they may have conflicting implementations - We should take the time to create a concise syntax - Arpad: There are quite a few instances of "(Format" in the specification - Walter: All that is needed are the words after "Format" - Take out "Format" and it should be OK - Bob: The BIRD for this change could be big and contentious - Walter: We could handle this with a Vector keyword - Mike L: Whatever we tell the developer will be to be in writing - Arpad: The tree syntax description on page 186 is inconsistent - Mike L: Contractually, how long do we have to reply to the developer? - Bob: We could ask for partial completion - Walter: We could say to ignore the Table section Arpad: How does this affect standardization around the IBIS 5 spec? - Bob: We will not try to standardize 5.0, it will be 5.1 Walter: SiSoft has sample models and code to go by - Arpad: Some models out there do not comply with the spec Arpad: What do we do about "(leaf5 value5 value6 value7)" - Walter: We had to support that non-compliant - Mike L: Is there value in that format? - Walter: The vendor that wants this writes on DLL for all models - These pass variable numbers of tap coefficients - Arpad: We might run into even more trouble beyond these issues - Mike L: We should be able to require having only one value per leaf - That syntax can serve any data need - Bob: It would be a problem for IBIS and the industry to go in separate directions - Arpad: They may be unwilling to change their DLLs - It may be better to support whatever existing DLLs do - Bob: For the contract we should accept a partial parser implementation AR: Arpad contact Cadence to check on making Model_Specific optional Next meeting: 14 July 2009 12:00pm PT -------- IBIS Interconnect SPICE Wish List: 1) Simulator directives