All,
What I tried to accomplish is that there is a difference between "Ground"
when making measurements of a Device Under Test (in vitro), and "Ground"
when simulating with a Device In Action (in vivo). Since IBIS is a
specification of how to generate data and not how to use it, then the
following paragraph is OK as is as long as we do not interpret or infer
from it how to apply the data in vivo.
The DUT die shows all of the available power and ground pin reference
voltage terminals. For many buffers, only one power pin and one common
ground pin terminal are used. The absolute GND pin is the reference for
the V_fixture voltage and the package model equivalent network. It can
also serve as a reference for C_comp, unless C_comp is optionally split
into component attached to the other reference voltages.
I do not think we need to add language to the specification on how to use
models.
So one intention was to make sure we understood the difference between
Ground in vitro and Ground in vivo, and that IBIS does not tell us how to
apply these in vitro measurement to in vivo simulations.
Walter
Walter Katz
<mailto:wkatz@xxxxxxxxxx> wkatz@xxxxxxxxxx
Phone 303.449-2308
Mobile 303.335-6156