Subject: IBIS BIRD54 - PACKAGE MODEL CORRECTIONS

From: [email-masked] (Bob Ross)
Date: Mon, 28 Sep 98 19:22:30 PDT

To All:

BIRD54 corrects a mistake in the IBIS Version 3.1 standard which causes
the ibischk3 parser to not process transmission line package models as
originally intended.  A (note 1) associated with a listing of keywords
needed to be revised.  BIRD54 covers this in more detail.

BIRD54 needs to be considered and approved before Version 3.2 can be
released.

Bob Ross
Interconnectix/Mentor Graphics

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BIRD ID#:       54
ISSUE TITLE:    Package Model Corrections
REQUESTER:      Bob Ross, Mentor Graphics, Stephen Peters, Intel Corporation
DATE SUBMITTED: September 28, 1998
DATE ACCEPTED BY IBIS OPEN FORUM: Pending

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STATEMENT OF THE ISSUE:

In compliance with an editorial mistake in the Package Modeling Section
the ibischk3 parser requires the Matrix Models defined even for tranmission
line sections.

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STATEMENT OF THE RESOLVED SPECIFICATIONS:

The Note (1) and list of required keywords needs to be corrected.

The original section is shown:

|=============================================================================
|=============================================================================
|
|                                 Section 7
|
|                      P A C K A G E   M O D E L I N G
|
|=============================================================================
|=============================================================================
|
| The [Package Model] keyword is optional.  If more than the default RLC
| package model is desired, use the [Define Package Model] keyword.
|
| Use the [Package Model] keyword within a [Component] to indicate the package
| model for that component.  The specification permits .ibs files to contain
| the following additional list of package model keywords.  Note that the
| actual package models can be in a separate <package_file_name>.pkg file or
| can exist in the IBIS files between the [Define Package Model]...
| [End Package Model] keywords for each package model that is defined.  For
| reference, these keywords are listed below.  Full descriptions follow.
| Simulators that do not support these keywords will ignore all entries
| between the [Define Package Model] and [End Package Model] keywords.
|
|   [Define Package Model]     Required if the [Package Model] keyword is used
|   [Manufacturer]             (note 1)
|   [OEM]                      (note 1)
|   [Description]              (note 1)
|   [Number Of Sections]       (Optional)
|   [Number Of Pins]           (note 1)
|   [Pin Numbers]              (note 1)
|   [Model Data]               (note 1)
|   [Resistance Matrix]        Optional
|   [Inductance Matrix]        (note 1)
|   [Capacitance Matrix]       (note 1)
|   [Bandwidth]                Required (for Banded_matrix matrices only)
|   [Row]                      (note 1)
|   [End Model Data]           (note 1)
|   [End Package Model]        (note 1)
|
| (note 1) Required when the [Define Package Model] keyword is used
|

The list of keywords is revised when adding (note 2) and (note 3):

|   [Define Package Model]     Required if the [Package Model] keyword is used 
|   [Manufacturer]             (note 1)
|   [OEM]                      (note 1)
|   [Description]              (note 1)
|   [Number Of Sections]       (note 2)
|   [Number Of Pins]           (note 1)
|   [Pin Numbers]              (note 1)
|   [Model Data]               (note 2)
|   [Resistance Matrix]        Optional when [Model Data] is used
|   [Inductance Matrix]        (note 3)
|   [Capacitance Matrix]       (note 3)
|   [Bandwidth]                Required (for Banded_matrix matrices only)
|   [Row]                      (note 3)
|   [End Model Data]           (note 2)
|   [End Package Model]        (note 1)
|
| (note 1) Required when the [Define Package Model] keyword is used
| (note 2) Either the [Number or Sections] or the [Model Data]/[End Model Data]
|          keywords are required.  Note that [Number of Sections] and the 
|          [Model Data]/[End Model Data] keywords are mutually exclusive.
| (note 3) Required when the [Define Package Model] keyword is used
|          and the [Number Of Sections] keyword is not used.
|

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ANALYSIS PATH/DATA THAT LED TO SPECIFICATION:

In IBIS Version 2.1, the [Pin Numbers] keyword list the pins and their order
to be used with the [Define Model] keyword that supported the coupled matrix
keywords.  (note 1) documented all of the required keywords in this context.

As a result of the BIRD28.3 and BIRD37.3 evolution, the syntax for the 
listing of pins under [Pin Numbers] was extended to include subparameter
sections for lumped and distributed elements.  The [Number Of Sections]
keyword was introduced.  (It had as stronger need when cascaded coupled
matrix sections were being discussed).  The final resolution was to support
both the matrix format of Version 2.1 and also the uncoupled lumped and
distributed elements on the [Pin Numbers] WITHOUT the matrix format of
Version 2.1.  The [Number Of Sections] keyword provided the flag that
[Pin Numbers] list now had additional elements.

The changed and extended keyword meanings are documented with the Package
Modeling section.   However, (note 1) was not properly reviewed when the
[Number of Sections] keyword was added to the list for IBIS Version 3.0.
Consequently, the [Define Model] keyword appeared to be required even
when uncoupled sections were documented.  (The ibischk3, version 3.1.0
parser requires this incorrect interpretation.)

BIRD54 corrects this editorial mistake by adding (note 2) and (note 3).
These notes document what is required when the package model has just
uncoupled lumped or distributed sections liste under the [Pin Numbers]
keyword.

It was never the intention to support the combination of BOTH partial
matrix descriptions for some pins and lumped or distributed sections for
other pins.

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ANY OTHER BACKGROUND INFORMATION:

See BIRD28.3 and BIRD37.3 under http://www.eda.org/pub/ibis/birds.

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