Subject: BIRD14 Comment

From: [email-masked] ( Bob Ross)
Date: Mon, 16 May 94 08:45:49 PDT

To IBIS Committee:

After hearing the discussion last Friday and talking to several people
including John Keifer at Intel, I now have changed my views and fully
support including Cref as part of IBIS Version 2.0.  Furthermore, I support
the view of Greg Doyle that Rref and Vref must also be included.  This
combination seems to cover most of the test setups typical of timing
specifications.

This specification appropriately puts IBIS right at the signal-integrity/
timing analysis interface.  For signal integrity analysis, you set rules
or test times of actual signals that have been based on internal device
propagation specifications and which are based on specified test load 
conditions.  Completion of the signal integrity timing analysis requires
that the loading effects of the actual load be compared with the loading
effects of the test load in order that the overall input to input timing
requirements are met.  So providing the test conditions within the IBIS
[Model] is very useful, particularly in relationship to some other 
features giving different ways of specifying the time response itself.
So I strongly support the inclusion of these parameters and could also
support making them required for Version 2.0.  The only issue in my
mind is logistics regarding possible default values and possible assumptions
for backward compatibility with Version 1.1 models.

Bob Ross
Interconnectix, Inc.