IBIS Macromodel Task Group Meeting date: 01 May 2012 Members (asterisk for those attending): Agilent: Fangyi Rao * Radek Biernacki Altera: * David Banas Ansys: Samuel Mertens * Dan Dvorscak * Curtis Clark Arrow Electronics: Ian Dodd Cadence Design Systems: Terry Jernberg * Ambrish Varma Feras Al-Hawari Celsionix: Kellee Crisafulli Cisco Systems: Ashwin Vasudevan Syed Huq Ericsson: Anders Ekholm IBM: * Greg Edlund Intel: Michael Mirmak LSI Logic: Wenyi Jin Maxim Integrated Products: * Mahbubul Bari Mentor Graphics: John Angulo Zhen Mu * Arpad Muranyi Vladimir Dmitriev-Zdorov Micron Technology: Randy Wolff 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 The meeting was lead by Arpad Muranyi ------------------------------------------------------------------------ Opens: - Arpad: There will be a meeting in Europe on the 15th - Bob will be traveling to that - We will plan to meet on the 15th -------------------------- Call for patent disclosure: - None ------------- Review of ARs: - Bob propose method for parameter passing - Bob: This may take a while - It may be hard to retrofit AMI style parameters into the existing structure - Arpad: It would help to have any alternatives to BIRD 117 in writing - Ambrish: Are AMI style parameters in the IBIS file the only concern? - Bob: Not sure exactly what the concern is - The tree structure may not be the answer - Walter/Bob update Table example based on discussion requests - Arpad: This should be deleted - Arpad to propose IBIS spec changes to clarify ISS D2A & A2D interfaces - Done, new BIRD proposal - Arpad revise BIRD 117 and 118 to generalize parameter file references - In progress - Ambrish update BIRD 145 for pad to pin mapping and other clarifications - Tabled, waiting for outcome of other issues ------------- New Discussion: BIRD 123.3: - Walter showed the latest BIRD draft - Rx_Clock)Recovery_Dj formula has "2*" because rand() outputs 0.0 - 1.0. - If it could be -1.0 to 1.0 it would match peak to peak values. - David: Is rand() defined? - Walter showed the definition of rand() - Walter: It could be -1.0 to 1.0 instead of 0.0 to 1.0 - This would affect the equation expressions - David motioned that Arpad and Walter would decide the equation format - Bob seconded - No one objected AR: Arpad and Walter decide on BIRD 123.3 equation formats - James: gaussian_rand() can go to infinity - Do we need to discuss limiting the tails? - Walter added a sentence about EDA tool handling of gaussian_rand(). - Arpad: We could work on this separately - Radek: The Open Forum asked us to work on this, we can decide next week Boundary Definition BIRD draft: - Arpad: Do we need to define supply terminal characteristics for s-parameters? - Radek: It's hard to imagine the impact on signal behavior - The impedance would not affect the data - Arpad: Would Touchstone files have power/ground connects to model capacitance? - Radek: That is not necessary - Walter: A distributed power network has to get the DC right because there may be a drop - Power to signal coupling is probably more important - Touchstone2 was created partly to have different port impedances - An ISS subckt with Touchstone would be up to the EDA tool - James: Agree - IBIS should not define what the network looks like - Arpad: Terminations will be part of an s-parameter model - Tools will need to know what is on the power side - James: Impedance conversion can be done without loss - Anything can be connected regardless of what the reference load was - Ambrish: Why would we have to define the boundary? - James: For the D2A and A2D it is because we have chosen to do so - Arpad: We were talking about zeros in the s-params, there were technical reasons - Ambrish: The question is if we need to define anything - James: The D side is within the scope of the spec - If we don't define the power supply why define the converters? - Arpad: We need to convey defaults - James: That's OK, but the user can choose their own power supply too - Radek: There should be an option on the voltage source - Walter: It's that way with the B element - Bob: In IBIS you can go up to s7p - Walter: This will be done with external circuits that have B elements - Bob: That is a theoretical problem, only some vendors will implement it - Arpad: With ISS we could have an s-param that connects to power and ground - Will people know how to generate it and use it? - Walter: We don't have to do anything special - Bob: A model has 7 connections but in practice they will not be used - Vendors will find a way to handle it - Arpad: Is this ready to submit to the Open Forum? - Arpad showed the proposed BIRD, which is quite short. - Bob motioned to submit the Boundary Definition BIRD to the Open Forum - Radek seconded - No one objected AR: Arpad submit Boundary Definition BIRD to Open Forum BIRD 150: - Walter showed BIRD 150 and explained it - Walter: It would be best if it had a new usage type: (Usage Dependency_Table) - Output options are Match, Closest, PWL, Range - What if a parameter has a hierarchical name? - Should we use dot separators? - Should we use parentheses? - This is similar to questions about BIRD 117/118 - This draft uses curly braces for variable substitution - These can be nested, at the request of Adge Hawes - Recommend scheduling a detailed review time for this - Arpad: This can be discussed in the next few meetings - We should all look at it - It is on the Open Forum website BIRD 121.2: - Walter showed BIRD 121.2 - Walter: We decided not to have Samples_Per_Bit - This adds Supporting_Files, DLL_Path, and DLL_ID - Recommend scheduling detailed review time for this - Arpad: The Open Forum website only has BIRD 121.1 AR: Walter send BIRD 121.2 draft for posting on ATM website ------------- Next meeting: 08 May 2012 12:00pm PT Next agenda: 1) Task list item discussions ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives