IBIS Macromodel Task Group Meeting date: 15 February 2011 Members (asterisk for those attending): Agilent: * Fangyi Rao * Radek Biernacki Ansoft: Chris Herrick Danil Kirsanov Ansys: * Samuel Mertens Dan Dvorjak Deepak Ramaswamy Jianhua Gu Cadence Design Systems: Terry Jernberg * Ambrish Varma Celsionix: Kellee Crisafulli Cisco Systems: * Mike LaBonte Stephen Scearce Ashwin Vasudevan Ericsson: Anders Ekholm IBM: Greg Edlund 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 Teraspeed Consulting Group: Scott McMorrow * Bob Ross TI: Casey Morrison Alfred Chong Vitesse Semiconductor: Eric Sweetman Xilinx: Mustansir Fanaswalla The meeting was lead by Arpad Muranyi ------------------------------------------------------------------------ Opens: - Walter: MM is investing new file formats - We might want to use DOC for easier revisions -------------------------- Call for patent disclosure: - None ------------- Review of ARs: - Ambrish draft BIRD for relationship between Type and Format - TBD - Arpad follow up with Kukal on BIRD 121 include file - TBD - Arpad check with Kumar and Vladimir on crosstalk in AMI_Init - Done - Walter send BIRDs 116-125 position email to list - Done - Bob draft BIRD for Tables - In progress - Bob investigate strings issue - In progress ------------- New Discussion: Arpad showed an email exchange between Bob and Atul: - Arpad: This is similar to row 25 in our task list - Bob: This was partially dealt with in BUG 109 - Other items should be amendments to BIRD 127 - We have to clarify that Tap is an integer represented as a float - Ambrish: I looked at BIRD 127 - Any new BIRD will depend on BIRD 127 anyway - BIRD 127 should be modified instead - Bob: BIRD 127 is submitted already - Arpad: But we can still change it AR: Bob check BIRD 127 for type clarification possibilities Arpad showed Bob's draft BIRD for Tables: - Bob: Adds AMI_Version - Keeps Use_Init_Output with a note - Ignore_Bits was mistakenly an Output - Maybe "No Jitter" should be "0" AR: Bob send draft Tables BIRD to Mike for posting Arpad: Should task list row 25 go into BIRD 127 too? - BIRD 127 is already large - Ambrish: It might take only 3 sentences - Bob: Maybe it should be another table Arpad: We had a question if Init should modify for crosstalk impulse response - We need to run a normal analysis first - Then run crosstalk analysis - This may become complicated - RX may sometimes have a peaking filter - This would need to modify the impulse response too - That gives us one more reason to allow modification - Should we remove the statement from the spec? - Arpad showed the IBIS spec 3.1.2.1 impulse_matrix section - The statement that might be removed is: "The aggressor columns of the matrix should not be modified" - Radek: Why do the aggressor TX Inits have to modify their impulse responses? - Walter: Ken suggested we add text to say what tools and model makers must do - Arpad showed 5 TX and 5 RX - All are both victims and aggressors - The matrix should have the response from the primary to all others - Arpad showed his "impulse_matrix and crosstalk in IBIS-AMI" slide - Walter: You have to assemble 5 x 5 impulse responses - Ken: Not all are needed if only the result at the middle RX3 matters - Arpad: Walter is right since TX1 coefficients depend on what RX1 sees - Fangyi: Only TX1 to RX1 and TX1 to RX3 are needed - Ambrish: Why TX1 to RX1? - Ken: All 5 channels must be characterized so TXs can set tap coefficients - Ambrish: Each TX wants the best behavior for it's own RX - Each one will look at this in a vacuum - Arpad: Tap coefficients are not set to control crosstalk - Ken: Each TX optimizes it's own channel then provide IR for crosstalk - Bob: Will they actually all be the same, since there are more adjacent channels? - Arpad: This came up because the spec says Init should not modify - We seem to agree it should be removed - Should the spec describe what to do? - Radek: Yes, the spec says nothing about handling multiple channels - Ken: We can do this with simple verbage - Arpad: We should continue this discussion by email AR: Ken draft language to clarify handling of multiple channels Arpad showed the task list: - Ken: Which is the Jitter BIRD? - Arpad: BIRD 123 - Walter: The Table type was created for jitter PDF - The Table format is: - 1st column is an ordinal number - 2nd column is time in UI - 3rd column is probability - Type UI would be meaningless for probability - Some use Table as In, not Info - We pass entire tables in using a single string - That is a better way to do it - Table should always be Info, for TX jitter - Arpad: Could we start a BIRD on this? - Ken: What happens to models that use Table as Input today? - It is legal - Walter: It is not legal - The first field has to be a number - This has to be settled before we write a BIRD - Ken: Table should not be limited that way - Ambrish: The spec doesn't say rows should begin with integers - Walter: Section 10 of the BIRD requires "(param_name ..." - But table begins with numbers - If it were allowed table could have only one row - Arpad: We should discuss this by email ------------- Next meeting: 22 Feb 2011 12:00pm PT Next agenda: 1) Task list item discussions ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives