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BIRD ID#:        100
ISSUE TITLE:     Allow Analog-Only *-AMS Model Terminals
REQUESTER:       Ian Dodd, Mentor Graphics; Arpad Muranyi, Intel Corporation
DATE SUBMITTED:  November 10, 2005
DATE REVISED:    
DATE ACCEPTED BY IBIS OPEN FORUM:  PENDING

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STATEMENT OF THE ISSUE:

The IBIS specification currently assumes that the signal ports of
[External Model]s and [External Circuit]s are purely digital when using the
*-AMS modeling languages, and a special syntax using A/D and D/A converters
is required when using (analog) SPICE models.

There are situations in which it may be desirable to have the capability of
defining purely analog terminals in *-AMS models to be used with IBIS through
the [External Model] and [External Circuit] keywords.  This BIRD describes a
change to the IBIS specification though which the referencing of *-AMS models
containing only analog terminals is allowed.

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STATEMENT OF THE RESOLVED SPECIFICATIONS:

The Language subparameter of the [External Model] and [External Circuit]
keywords shall have two additional options, namely "VHDL-A(MS)" and
"Verilog-A(MS)", in which the parentheses indicates that the model uses
only analog terminals.  When such references to the *-AMS languages are made
in [External Model]s and [External Circuit]s, the requirements of using the
A_to_D and D_to_A converters with SPICE models shall apply to the *-AMS
models as well.

Change the following section under the [External Model] and
[External Circuit] keyword descriptions:

|               Language:
|
|               Accepts "SPICE", "VHDL-AMS", or "Verilog-AMS" as arguments.
|               The Language subparameter is required and must appear only
|               once.

to:

|               Language:
|
|               Accepts "SPICE", "VHDL-AMS", "Verilog-AMS", "VHDL-A(MS)"
|               and "Verilog-A(MS)" as arguments.  The Language subparameter
|               is required and must appear only once.

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ANALYSIS PATH/DATA THAT LED TO SPECIFICATION

Additional detail and/or specification changes may be required to make the 
BIRD fully compatible with the features and syntax of Section 6b.

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ANY OTHER BACKGROUND INFORMATION:

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