IBIS Macromodel Task Group Meeting date: 14 April 2015 Members (asterisk for those attending): ANSYS: * Dan Dvorscak * Curtis Clark Avago (LSI) Xingdong Dai Cadence Design Systems: * Ambrish Varma Brad Brim Kumar Keshavan Ken Willis eASIC * David Banas Ericsson: Anders Ekholm IBM Steve Parker Intel: * Michael Mirmak Keysight Technologies: * Fangyi Rao * Radek Biernacki * Nicholas Tzou Maxim Integrated Products: Hassan Rafat Mentor Graphics: * John Angulo * Arpad Muranyi Micron Technology: * Randy Wolff Justin Butterfield QLogic Corp. James Zhou Andy Joy eASIC Marc Kowalski SiSoft: * Walter Katz * Todd Westerhoff * Mike LaBonte Synopsys Rita Horner Teraspeed Consulting Group: Scott McMorrow Teraspeed Labs: * Bob Ross (Note: Agilent has changed to Keysight) The meeting was led by Arpad Muranyi. ------------------------------------------------------------------------ Opens: - Arpad: We are hoping for a vote on package model updates. -------------------------- Call for patent disclosure: - None ------------- Review of ARs: - Walter send updated PAM4 BIRD to Mike for posting. - Done - Randy send updated C_comp BIRD to Mike for posting. - Done - Michael M update AMI Directionality BIRD - No update - Arpad to review IBIS specification for min max issues. - In progress. ------------- New Discussion: BIRD 175: - Arpad showed the updated BIRD 175. - Arpad: The question is what to do for pins not in [Pin Numbers] and not in [Merged Pins] - The rule says it should be unconnected if part of a bus. - Pin 7 here will be disconnected and simulation will fail. - It could be RLC modeled, but that would be incorrect. - We could disallow the situation. - All pins of a [Pin Mapping] bus would have to be in [Pin Numbers] or [Merged Pins]. - Radek: It is still conditioned on existence of [Merged Pins]. - With no [Merged Pins] that is another case. - Mike L: Is "and/or" valid here? - Each pin in [Merged Pins] has to be in [Pin Numbers]. - Arpad: The pin after the [Merged Pins] keyword is in [Pin Numbers] - The others are not. - Radek: Agree. - Arpad: Radek suggested changes to the red text on page 4. - Radek: An open circuit conflicts with the [Merged Pins] section. - Arpad: The open is between pin and pad, but that does not make it totally open. - Radek: It needs to be stated more precisely. - The RLC must no be used for that pin and pad. - Randy: Was that in an email? - Arpad emailed the file to Randy. - Arpad pointed out suggested text from Radek. - Arpad: The reader does not know about the [Merged Pins] keyword at this point. - Radek: We should not use the term "open circuit". - Randy: Either text is OK. - Bob: This paragraph can apply to connections without [Merged Pins]. - Randy: We could say it creates a no-connection between pin and pad. - Arpad: We call it a no-connect but the [Merged Pins] creates a connection later. - Radek: In the para starting with "Each pin name" (page 5). - "may not be present" should be "shall not be present". - Bob: Is this the draft with the table in it? - Arpad: We can discuss that later. - Radek: If [Pin Mapping] is present but not [Merged Pins] is this allowed? - Arpad: The first part of the red paragraph covers that. - Radek: The second sentence excludes the [Pin Mapping] pins. - Arpad: The "However" is the exception to the first part. - Radek: RLC is limited to pins not under [Pin Numbers] and not under [Pin Mapping]. - Arpad: Disagree. - Randy: Bob's table may help. - Arpad: That may be in the BIRD but it will not be in the specification. - Bob: The first sentence does not say "Without [Pin Mapping]". - Arpad: We need to take this offline. - Arpad showed a table of rules drafted by Bob. - Arpad: The background section of the BIRD has been updated to include this. - Bob: The rules for signal pins are unchanged. - Up to 6.0 we never say the power/GND pins are treated differently. - Circuit call is illegal with [Pin Mapping]. - For Power/GND pins many cases are the same. - Where [Pin Mapping] and [Pin Numbers] exist but not [Merged Pins] the rule changes. - With [Merged Pins] we always use model data from [Pin Numbers] - This is where the "all bus pins must be accounted for" rule comes in. - A bus might connect to no [Pin Numbers] at all and there we use RLC. - Radek: In the third case why is [Merged Pins] illegal? - Bob: [Merged Pins] requires [Pin Numbers]. - Radek: This is a usefulness issue. - The second sentence under "However" should have the statement about [Merged Pins]. - Arpad: Disagree, they are unrelated. - Bob: Agree with Arpad. - The first part is a general rule, [Merged Pins] has not come up yet. - Arpad: There should be no rule duplication. - Radek: It first excludes the rule then it allows it. - Bob: Should the table be in the specification? - Arpad: Is this ready for submission to the Open Forum for a vote? - Bob: We do not have a complete draft ready yet. - Mike L: Could these issues be settled in the editorial committee? - Radek: We can work on it this week and have it ready next week. AR: Arpad, Randy and Radek prepare BIRD 175 draft ready for Open Forum. PAM4 BIRD: - Walter: I suggested a paragraph to explain Bit Time, etc. - I will find the places in IBIS that are affected. - Draft 15 will address this. AR: Walter find all places in IBIS specification affected by PAM4 BIRD. Directionality BIRD: - No update. C_comp BIRD: - Randy: The C_comp BIRD is open for comments. Back-channel BIRD: - Walter: No progress on back-channel. ------------- Next meeting: 21 Apr 2015 12:00pm PT ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives