From:	Mirmak, Michael
Sent:	Wednesday, August 27, 2014 6:37 PM
To:	IBIS-Interconnect (ibis-interconn@freelists.org)
Subject:	Minutes, IBIS Interconnect Task Group Meeting, Aug. 26, 2014

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IBIS INTERCONNECT TASK GROUP
http://www.eda.org/ibis/interconnect_wip/   
Mailing list: ibis-interconnect@freelists.org 
Archives at http://www.freelists.org/archive/ibis-interconn/ 
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Attendees from Aug. 26 Meeting
Altera                                                                                    David Banas
ANSYS                                                                                   Steve Pytel
Cadence Design Systems                                              Brad Brim*, Ambrish Varma
Intel                                                                                       Michael Mirmak*
Keysight Technologies                                                   Radek Biernacki*
Mentor Graphics                                                              Arpad Muranyi*
Micron Technology                                                         Justin Butterfield*, Randy Wolff
QLogic                                                                                   James Zhou
Signal Integrity Software                                              Walter Katz*
Teraspeed Consulting Group                                      Bob Ross*

Minutes from Aug. 26 meeting
No patents were declared.  Michael Mirmak suggested, as an open, that the team review Bob Ross’s two 
sentences on universal ground handling to be added to the interconnect treatment.  Arpad Muranyi 
asked where these sentences would go: BIRD or IBIS-ISS?  Bob suggested they were intended for the 
interconnect BIRD.  
AR: Michael to post two-sentence document to the web for archive purposes
Bob suggested that the ground treatment/recommendations could be added to the list of IBIS-ISS 
recommendations at the end of the document.  This is where scale factor X is described as not 
recommended, but not prohibited.
Brad Brim suggested that the wording be slightly changed, as “usually interpreted as” is actually “are” 
global ground, per IBIS-ISS specification definition.
Compiling Existing Text
The Interconnect Subparameters document from Bob has not yet been included in the Draft 8 of the 
Interconnect Modeling BIRD from Walter Katz.  Bob suggested that the structure is similar to multi-
lingual section of IBIS.  No comments have been received since the last review.  
Walter suggested that an EBD enhancement BIRD will be needed later, to address EBD improvements. 
Arpad clarified that there was a restriction involving stacked die treatments related to many of these 
proposals.  Which of these restrictions would be involved in this BIRD?  Walter explained that EMD is 
EBD with path sections replaced with subcircuits.  EMD can be made to look like this packaging 
treatment, to address fork, endfork, etc. as they are not in this BIRD>  
Key missing areas and owners
1)	Pin Mapping treatment (Michael) 
If mutually exclusive with package interconnect, need similar function defined that is 
compatible. Walter prefers to keep the existing keyword. 
2)	Pre-layout vs. post-layout notation (Walter)
3)	Rules of precedence for different package modeling methods (Walter)
4)	Interaction with Circuit Call and External Circuit (Arpad)  
Walter asked whether the approach simply needed need pin-to-die-pad connections. Pin-to-buffer and 
pad-to-buffer may be challenging.  Walter proposed that new models should be incompatible with 
External Circuit and Circuit Call for pin-to-buffer connections.  It would be allowed with External Model.
Arpad noted that Pin Mapping is now prohibited with External Circuit and Circuit Call. Walter's position 
is to deprecate both.  Arpad needs a complete draft to discuss with his colleagues.
AR: Walter to roll Bob's parameter/subparameter text into a Draft 9 of the BIRD.  
5) Unused Terminal text (Brad to update existing draft text)
6) Die Supply Pads (Walter) - the text is new in Draft 8 and needs review
7) Examples on page 15 in red to be removed (Walter)
The current draft has already resolved issues around Terminal/Terminals/Node nomenclature, reference 
nodes, and number of terminals supported.
8) Define Package Model (?).  The team agreed to make this keyword mutually exclusive with the 
proposed text.  Bob noted that the new interconnect approach would be the preferred/top level 
supported, with the traditional precedence following it: [Define Package Model], [Package], [Pin].
Arpad noted that we have override rules in the specification for the package keywords.  However, 
[Alternate Package Model] provides a choice.  The EDA tool is not prohibited from choosing among 
package keyword options.
Michael asked whether both are allowed to be present in the same component: [Package] and ISS?  Bob 
suggested so.  Arpad added that this allows tools that may not have particular keywords implemented to 
use the next available one.
Bob noted that, on page 6 of the current draft, the new parameter names should be listed as 
subparameters, and followed by the “=” character.  AR: Bob to correct this.
The next meeting will focus on discussion of Circuit Call/External Model support with this proposal.  In 
addition, the team should consider whether (per Randy Wolff’s request) that the next IBIS version can 
be released with this BIRD, if approved, but not with the EMD extensions.