Integrated Microcomputer Division Folsom California Date: April 23, 1993 From: Donald Telian (916) 356-5029, fax -6710 Subject: Minutes from IBIS Open Forum 4/23/93 To: Attendees, list Attendees: Hyperlynx - Kellee Chrisafulli, Steve Kaufer Integrity Engineering - Greg Doyle Intel Corporation - Gary Saunders, Arpad Muranyi, Donald Telian IntuSoft - not present Meta-Software - Stephen Fenstermaker, Mei Wong MicroSim - Arthur Wong Quad-Design - Jon Powell Quantic Labs - Mike Ventham, Zhen Mu List: Intel - Randy Wilhelm, Will Hobbs, Tim Schreyer Overall Summary: This document contains the minutes of the first IBIS Open Forum, held on April 23, 1993. The meeting was attended by six of the seven software simulation tool vendors who have announced support of IBIS modeling. In general, the meeting was quite successful, with all attendees playing an active role in the meeting's progress and objectives. Good cooperation across the board, with a "get the job done" attitude prevailing. All questions regarding the test waveform/circuits were answered, and all portions of the ASCII template were resolved except for the V/I curves and ramp times. That discussion was tabled until the 5/7 meeting. Though not agreed to at the meeting, it seems that the first revision of the ASCII template could be closed after two more meetings. Open Issues: Various issues were brought up during the meeting. I'll use this section to track those issues, and site when they'll most likely be addressed # | Description | Owner | On Agenda When? | Done 1 | New Keyword under pullup/pulldown | Powell | During V/I disc. on 5/7 | 2 | tri-state v/i curve | GD/JP | " | 3 | Hierarchical model/file structures | Doyle | " | 4 | How is v/i and ramp data derived | Wong | " | 5 | if & when to pass IBIS 1.0 to stds committee | Doyle | 5/21 or 6/4 | 6 | golden parser, what is it? who owns it? | Powell | 5/21 | 7 | format of PKG file | Telian | 6/4 | 8 | thresholds for timing | Powell | 5/7 or 5/21 | Minutes: I. IBIS Update and Open Forum Guidelines: After some introductory remarks, Telian announced: 1. IBIS Name Change: "IBIS" now stands for "I/O Buffer Information Sheet" instead of "Intel Buffer Information Sheet". In addition, the lower-case "i" used before in "iBIS" has been changed to upper-case "I" or "IBIS". These changes come from within Intel, and help encourage industry-wide participation in IBIS modeling. 2. EDN Contact: Many forum participants have sent information to Charles Small at EDN. He has confirmed that he would like to continue to receive information, and is also still interested in reporting on IBIS. He also stated that participants should also be sure to send information to Doug Connor (also at EDN), who is now chartered to cover developments in CAE/CAD software. II. Technical Discussion of IBIS_ASCII TEMPLATE.IBS: The group resolved the following to allow the simple/logical parsing of the IBIS_ASCII electronic format. The items below follow, in general, the sections of the ASCII template. 1. Comments. The group accepted the "pipe" character, or "|", as the symbol to denote that all information following it on that line is a comment. We also defined a new keyword [Comment] that will define the character used in the file as follows: [Comment] |_char. As a convention, the character that denotes comments can be used literally by typing it twice, or ||. 2. Case Sensitivity. Elements in the file can be case sensitive, with the exception of keywords and filenames. Keywords are NOT case sensitive, and file names must be written as lower case characters to enhance Unix/DOS compatibility. 3. Keywords. Keywords are now set off from the rest of the file by square brackets on both sides as [Keyword]. In addition, they must begin in the first column. This proposal was adopted in favor of the colon used before, and has the nice feature that a wide variety of keyword(s) can be used, as well as clarifying the termination of the previous keyword data with a [. 4. Continuation Characters. The use of continuation characters is a artifact from Fortran, and will not be carried forward into IBIS. 5. Keyword Order. The start of the ASCII file will always begin with keyword [IBIS_ASCII Ver] and then [Comment]. More work on the ordering of following keywords is definitely still in order. 6. Character Limitations. Component names are limited to 40 characters max. Pin designators are alphanumeric, and 5 characters max. Model names and signal names are both limited to 20 characters max. 7. Fields in [Pin] Keyword. The [Pin] keyword will now contain ONLY columns for pin, signal_name, and model_name. The previously optional VCC and GND columns were dropped, and will possibly be used in a later version of the ASCII template. 8. Reserved Signal/Model Names. For obvious reasons, the names GND, NC, and POWER are reserved, and will be used in the file to denote ground, no-connect, and power pins respectively. POWER was chosen to as the preferred name for power over PWR and VCC or VDD. 9. Model Types. The following types are allowed: INPUT, OUTPUT, I/O, TRISTATE. Though not discussed, i'd like to also add OPEN-DRAIN. In addition, model_type, polarity, and enable are no longer keywords. The "signals" designator under [Model] is now considered a comment field. 10. Input Thresholds. Some discussion arose about input and switching thresholds, hysteresis, etc. This discussion was tabled until later. 11. Typ/Min/Max Column Conventions. Numeric values in tables of packaging, v/i, and ramp data will follow the format typ/min/max. The "typ" column must be supplied, min/max may be optional. This is still tbd, but it simplifies either implementation to consistently list typ first. III. Technical Discussion on IBIS Test Circuits Document: Everyone was clear on the simulations to be performed. Telian will re-send diagrams, since shading made some faxes unreadable. The following clarifications were made: 1. Input Edge Rate. Those simulators that will drive the buffer with a pulse should use an input edge rate of 2.5 ns, rail-to-rail. 2. Board Stack. For circuit #3, the "line" layer (16 mils from ground) should be buried microstrip, and the "stub" layer should be surface microstrip. The dielectric constant is 4.7. IBIS Open Forum: Minutes of 4/23/93 Meeting, Page 1 IBIS Open Forum: Minutes of 4/23/93 Meeting, Page 3