Proposed revisions to BUG49; comments?

IBIS folks,

In today's IBIS Open Forum Meeting, several people made very useful
suggestions regarding IBISCHK BUG49; thanks to everyone who participated.

To address these comments, I have added a section called "ADDITIONAL NOTES"
to the original BUG49 proposal. The updated text is shown below.
Discussion is welcome.

If the additions resolve the Forum members' concerns, I will file the
updated text with Bob Ross for discussion and a vote at the next Open
Forum meeting.

Thanks again!

- Michael Mirmak, Intel Corp.
  michael.mirmak@intel.com

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********************* IBIS GOLDEN PARSER BUG REPORT FORM
*********************
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INSTRUCTIONS

To report a bug in the IBIS golden parser. Please fill out the top part
of the following form and send the complete form to ibischk-bug@vhdl.org.

A list of reported bugs will be maintained on vhdl.org.

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PARSER VERSION NUMBER: 3.2.5

PLATFORM (SPARC, HP700, PC, etc.): HP

OS AND VERSION: HP_UX (B.10.20)

REPORTED BY: Michael Mirmak, Intel Corp.

DATE: November 2, 2000

REVISED: November 17, 2000

DESCRIPTION OF BUG:

"Dangling" models, present but not referenced or used in the file, are not
flagged to the user. These include [Model]s which are not described in
[Pin], [Model Selector] or [Driver Schedule] sections and also [Submodel]s
which are not referenced by any [Add Submodel] declaration.

Some indication -- most appropriately, a warning -- should be made of the
lack of reference for these models and model fragments.

An example:

  WARNING (line xxx) - Model xxx not referenced in [Pin], [Model Selector]
  or [Driver Schedule] sections.

For Submodels:

  WARNING (line xxx) - Submodel xxx not referenced by [Add Submodel]
  keyword.

This bug also applies to DOS32 IBISCHK3 v3.2.5.

ADDITIONAL NOTES:

As pointed out by Mike LaBonte of Cadence, this BUG should also apply to
[Model]s which are not referenced in a [Series Pin Mapping] section.
Therefore, a "dangling" [Model] is one which, while syntactically correct,
is not referenced in [Pin], [Model Selector], [Driver Schedule] or [Series
Pin Mapping] sections.

Ian Dodd of Cadence raised the point that, for devices such as an FPGA, an
unreferenced [Model] may be desirable in a user-ready model (such a [Model]
might represent a available programming option which may or may not be
implemented after the user configures the device). In addition, generating
a message for every instance of an unreferenced [Model] may be unnecessarily

confusing to the user.

To address the above, the following changed messages are proposed:

For one or more instances of an unreferenced [Model]:

  WARNING (line xxx) - [Model] zzz not referenced in [Pin],
  [Model Selector], [Driver Schedule] or [Series Pin Mapping] sections.

Only one instance of the above warning message should be generated, for
the first unreferenced [Model] in the file. Multiple unreferenced [Model]s
in an IBIS file should NOT generate multiple warning messages.

For Submodels:

  WARNING (line xxx) - [Submodel] zzz not referenced by [Add Submodel]
  keyword.

As [Submodel]s should not exist independently of a referencing [Add
Submodel]
keyword, the above message should be generated for EVERY instance of
an unreferenced [Submodel].

INSERT IBIS FILE DEMONSTRATING THE BUG:
|***********************************************************************
|
[IBIS Ver] 3.2
[File Name] bug49tst.ibs
[File Rev] 0.0
[Date] 02-November-2000
[Source] File created from specification
|
[Disclaimer]
    (C) Copyright 2000 Intel Corp.
    All rights reserved
    This model is for demonstration purposes only.
|
|
[Component] GENERIC_IBIS
[Manufacturer] Intel Corp.
|
[Package]
| typ min max
R_pkg 6.0mO 5.0mO 7.0mO
L_pkg 5.0nH 2.0nH 8.0nH
C_pkg 1.0pF 0.5pF 1.5pF
|
|
[Pin] signal_name model_name R_pin L_pin C_pin
    A1 TestSignal1 TestModel
    A2 TestSignal2 TestModel
|
|************************************************************************
|
[Model] TestModel
Model_type Output
Polarity Non-Inverting
Cref = 10.0pF
C_comp 5.00pF 4.00pF 6.00pF
|
|
[Temperature Range] 27.00 100.00 0.00
[Voltage Range] 3.30V 3.00V 3.60V
[Pulldown]
| voltage I(typ) I(min) I(max)
|
  -3.3000 -20.0A -25.00A -15.00A
   0.0000 0.0A -5.00nA 5.00nA
   3.3000 40.00mA 32.00mA 48.00mA
   6.6000 10.0A 12.0A 8.00A
|
[Pullup]
| voltage I(typ) I(min) I(max)
|
  -3.3000 10.00A 12.00A 8.00A
   0.0000 0.0uA -0.30uA 0.30uA
   3.3000 -65.00mA -40.00mA -80.00mA
   6.6000 -22.00A -25.00A -19.00A
|
[Ramp]
| variable typ min max
dV/dt_r 0.35/1.6n 0.25/1.8n 0.45/1.5n
dV/dt_f 0.35/1.6n 0.25/1.8n 0.45/1.5n
R_load = 50.000
|

|***************************************************************************
|
[Model] TestModel2
Model_type Output
Polarity Non-Inverting
Cref = 10.0pF
C_comp 5.00pF 4.00pF 6.00pF
|
|
[Temperature Range] 27.00 100.00 0.00
[Voltage Range] 3.30V 3.00V 3.60V
[Pulldown]
| voltage I(typ) I(min) I(max)
|
  -3.3000 -20.0A -25.00A -15.00A
   0.0000 0.0A -5.00nA 5.00nA
   3.3000 40.00mA 32.00mA 48.00mA
   6.6000 10.0A 12.0A 8.00A
|
[Pullup]
| voltage I(typ) I(min) I(max)
|
  -3.3000 10.00A 12.00A 8.00A
   0.0000 0.0uA -0.30uA 0.30uA
   3.3000 -65.00mA -40.00mA -80.00mA
   6.6000 -22.00A -25.00A -19.00A
|
[Ramp]
| variable typ min max
dV/dt_r 0.35/1.6n 0.25/1.8n 0.45/1.5n
dV/dt_f 0.35/1.6n 0.25/1.8n 0.45/1.5n
R_load = 50.000
|
|***************************************************************************
[Submodel] Submodel
Submodel_type Dynamic_clamp
|
[Power Clamp]
| voltage I(typ) I(min) I(max)
|
  -3.3000 10.00A 12.00A 8.00A
   0.0000 0.0A 0.30A 0.30A
   3.3000 0.00A 0.00A 0.00A
   6.6000 0.00A 0.00A 0.00A

|***************************************************************************
|
[End]
|
|
|Parser 3.2.5 responds with
|
|IBISCHK3 V3.2.5
|
|Checking bug49tst.ibs for IBIS 3.2 Compatibility...
|
|Errors : 0
|
|File Passed
|

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******************** BELOW FOR ADMINISTRATION AND TRACKING
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BUG NUMBER: 49

SEVERITY: [FATAL, SEVERE, MODERATE, ANNOYING, ENHANCEMENT]

PRIORITY: [HIGH, MEDIUM, LOW]

STATUS: [OPEN, CLOSED, WILL NOT FIX, NOT A BUG]

FIXED VERSION:

FIXED DATE:

NOTES ON BUG FIX:

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Received on Fri Nov 17 10:40:41 2000