All,
First, I think the IBIS specification should always assume that a .ibs
file is a description of a full component, not a subset, or slice of a
real component, and not a description of a virtual component, that just
has one Input model (the famous WOM).
However, there is nothing that prevents a model maker from delivering an
IBIS file that represents a Virtual component, as long as the model maker
documents to the user of that IBIS file how it is to be used.
There is ample opportunity for a model maker to put such instructions into
one of [Source], [Notes] or [Disclaimer].
If there was an IBIS Keyword, either under the File Header Section, or the
[Component] section; What would the EDA tool do with it? What would the
User tool do with it? What would the company that contracted for the model
do with it?
I suggest we could add a new File Header Section titled [Partial Model
Instructions]. This is no different than [Notes], except that it is a
statement by IBIS that it is legal in the standard to create IBIS files
with partial component data or IBIS files that are a container of I/O
buffer [Model]s, and Interconnect models for a specific I/O Buffer IP, or
package IP.
I am sure that we all have experience in either generating or using such
partial models, and that the instructions on how to use these models
varies considerably, and will be difficult to codify and add to the
standard. That is why I suggest just formally acknowledging that such IBIS
files exist, and at least putting in a place where the model maker should
(but will not be required to) add instructions to the User and EDA tool on
how to use this file.
Walter
Walter Katz
<mailto:wkatz@xxxxxxxxxx> wkatz@xxxxxxxxxx
Phone 303.449-2308
Mobile 303.335-6156
