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BIRD ID#:        126
ISSUE TITLE:     IBIS-AMI New Reserved Parameter AMI_Version
REQUESTER:       Walter Katz, SiSoft; Arpad Muranyi, Mentor Graphics, Inc.
DATE SUBMITTED:  December 14, 2010
DATE REVISED:    
DATE ACCEPTED BY IBIS OPEN FORUM:

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STATEMENT OF THE ISSUE:

It is necessary that any software tool that uses an AMI model know the
revision level of the AMI modeling language that the model is designed
to support.  The current version of the IBIS specification (5.0) includes
features in AMI modeling that are either removed or deprecated, and in some
cases the syntax of the language has been modified.  Since IBIS requires
that any IBIS file compliant with a specific release of IBIS must also be
compliant with any future release of IBIS, the AMI model itself needs to
be able to tell the software tool whether it was written to the initial
IBIS Version 5.0 specification or some later version.

This BIRD proposes a new Reserved Parameter called “AMI_Version”.  This
parameter will be required for any AMI model that is written according
to a specification that supersedes IBIS Version 5.0.

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STATEMENT OF THE RESOLVED SPECIFICATIONS:


On pg. 144 add the following lines before "Init_Returns_Impulse:"

|*              AMI_Version:
|*
|*              AMI_Version is of format Value, Type String and Usage Info
|*              that specifies the version of the AMI modeling language.
|*
|*              This parameter is required in the .ami parameter files of
|*              AMI models which are written in compliance with the IBIS
|*              Version 5.1 or later specification(s), but it is not allowed
|*              in the .ami parameter files of AMI models which are written
|*              in compliance with the IBIS Version 5.0 specification.  When
|*              required, this parameter must be the first parameter defined
|*              in the Reserved_Parameter branch of the .ami file.
|*
|*              The value of this parameter shall be "5.1" or greater for
|*              AMI models written in compliance with the IBIS Version 5.1 or
|*              later specifications.  The absence of AMI_version indicates
|*              that the AMI model was written in compliance with the IBIS
|*              Version 5.0 specification.
|*
|*              The version numbers of .ibs files and AMI models do not have
|*              to match.  The EDA tool is expected to execute the AMI model
|*              according to the rules of the specification which corresponds
|*              to its version number.
|*
|*              Example:
|*
|*                 (AMI_Version (Value "5.1") (Usage Info)(Type String))
|*
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ANALYSIS PATH/DATA THAT LED TO SPECIFICATION

The parameter defined in this BIRD will permit AMI model developers to
programmatically indicate the version of AMI modeling that is supported
by this model.  It is legal for .ibs files and .ami files to have different
version numbers provided that:

1) A .ibs file must be 5.0 or above to support the [Algorithmic Model]
   keyword

2) The version number in the .ami file must be "5.1" or greater, or omitted,
   which implies that the version is 5.0

The ibischk5 parser with the -ami flag will check the .ibs and the .ami
file feature set at their designated version number (or in the case of
.ibs, at the final major version number level used for official
standardization).  The EDA tool is responsible for processing each of the
files at their specified version number level.

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ANY OTHER BACKGROUND INFORMATION:
This BIRD was released to the IBIS Open Forum for consideration after a 
unanimous vote of the IBIS Advanced Technology Modeling Task Group on Dec. 
14, 2010.

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