Subject: IBIS EXPRESS INFORMATION MODEL

From: [email-masked] ( Bob Ross)
Date: Fri, 22 Mar 96 09:28 PST

To IBIS Members:

Tom Thurman has concerns putting ANSI/EIA-656 (IBIS Version 2.1) on
a fast track path for international standardization.  His primary
objection is the lack of an EXPRESS information based model.  Per the
discussion at the last meeting, we have invited Tom to participate
in the March 29, 1996 meeting to help us understand the EXPRESS
information model and what it might take to provide one.  Because of
his committments that day and because of his interest in physical
representations, we have scheduled this discussion after 9:00 A.M PST.

Tom's response is attached.

Bob Ross,
Interconnectix, Inc.
Secretary, EIA/IBIS Committee

 Regarding the proposal to fast track the IBIS spec.
 
 I vote no for the following reasons:
 
 1) there is no EXPRESS based information model in the document.
 
 2) there appears to be information in the document that is overlapping 
 with the information in the C/ATLAS document (signal specifications),
 and perhaps in standard VHDL packages, but there is no information
 provided to show the relationships to these ANSI standards.
 
 3) some of the information (pin-mapping) appears to be overlapping
 to that in ISO CD 10303-210 and EDIF 3 0 0.  
 
 4) some of the information (package definition) appears to be
 overlapping to that in ISO CD 10303-210 and EDIF 3 5 0.
 
 Item 1 will increase the effort required to interface
 this important document into the ongoing efforts in WG1, WG3 and
 ISO/TC184/SC4/JWG9.
 
 Item 1 will increase the effort required to review the document
 during the ballot process, and likely will lessen the quality
 of the review since reviewers typically aren't funded to develop
 the required information model necessary for a useful review.
 
 I will change my No to a yes if an information model is
 made available for review by the developers of the IBIS
 standard. (They have verified that the information model provided meets
 the domain semantics encoded in the standard.)
 
 Regards,
 Tom
 
 --
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 | Thomas R. "Tom" Thurman             PDES INC. EE TEAM MEMBER      |
 | Principal Engineer                                                |
 | Rockwell Collins Avionics and Communications Division             |
 | 400 Collins Road N.E.    phone:(319)395-2280                      |
 | Cedar Rapids Ia, 52498, USA            FAX:(319)395-5429          |
 |               email:  [email-masked]                  |
 |       opinions expressed are those of the author                  | 
 |               and not necessarily of his employer                 |
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