[IBIS-Users] RE: Question regarding .pkg versus simple RLC

Frank,
I can only speak for Cadence SQ tool since you mentioned how simulator
does for this.

There are three sections in IBIS can give Pin Parasitic information:
[Package]
[Pin]
[Package Model]

In Cadence SQ tools, the usage priority setting from high to low is
[Package Model] to [Pin] to [Package] by following IBIS Guideline.
Another words, if [Package Model] is present, it overrides all others.
So, to answer your question, yes, Cadence SQ tools do take the advantage
of [Package Model] information. And I believe the most of other EDA
tools do the same way too. Someone from other vendors can confirm it.

If you want to ask the questions specifically about Cadence tools,
please send me an email offline.

Hope this helps,

Best regards,

Liqun Wang (Lance)
Cadence Design Systems, Inc.
978-262-6685

                -----Original Message-----
                From: owner-ibis-users@eda.org
[mailto:owner-ibis-users@eda.org] On Behalf Of Frank Dunlap
                Sent: Wednesday, March 10, 2004 9:09 PM
                To: Ibis-Users (E-mail)
                Subject: Question regarding .pkg versus simple RLC

                Presumably, a .pkg file provides "more" information than
the simple RLC in the [Pin] section of an IBIS model. Assuming that's
the case, do simulators actually take advantage of this additional
information? Are there cases where a .pkg file is preferred? Are there
cases when it's not preferred, such as where its added complexity may
cause problems?

                Furthermore, is there a straightforward relationship
between RLC values that would appear under the [Pin] section in an IBIS
model, and corresponding values that would appear in a .pkg file?

                Here's an example from the [Pin] section of an IBIS
model:

                [Pin] signal_name model_name R_pin L_pin
C_pin
                AE6 HINT# V33OP 2.170 8.506nH
6.636pF
                AE5 HRW# V33OP 2.165 8.475nH
5.865pF
                C16 S_A00 V33OP 1.332 3.287nH
3.472pF

                Here's an example from a .pkg file:

                [Resistance Matrix] Banded_matrix
                [Bandwidth] 0
                [Row] 2255
                 1.74791e+000
                [Row] 2253
                 1.74386e+000
                ...
                [Inductance Matrix] Sparse_matrix
                [Row] 2255
                2255 1.21125e-008
                2253 1.70009e-010
                B19 1.73505e-010
                [Row] 2253
                2253 1.25283e-008
                J21 1.22831e-010
                F20 1.89512e-010
                K21 4.09167e-010
                ...
                [Capacitance Matrix] Sparse_matrix
                [Row] 2255
                2255 4.40327e-012
                2253 -2.82931e-015
                B19 -1.47570e-015
                [Row] 2253
                2253 4.33757e-012
                J21 -1.04449e-014
                F20 -2.65107e-015
                K21 -8.93602e-015

                The .pkg and [Pin] information are from two different
data sets. I'm sorry, but I don't have both .pkg and [Pin] information
from a common data set.

                Thanks in advance for any guidance,

                Frank

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Received on Thu Mar 11 06:55:43 2004