Author:  71436.1314@compuserve.com at SMTPGATE
Date:    10/28/94  1:13 AM
Priority: Normal
TO: ibis@vhdl.org at SMTPGATE
BCC: Derrick Duehren at JFCCM2
Subject: Resending Bird20, from Kellee Crisafulli
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                      Buffer Issue Resolution Document  (BIRD)
 
BIRD ID#:      20.0
ISSUE TITLE:   Error correction regarding monotonicity statement in V2.1
               IBIS specification.
REQUESTOR:     Kellee Crisafulli, HyperLynx Inc. 
DATE SUBMITTED:                       10-10-94 
DATE REVISED:                         TBD
DATE ACCEPTED BY IBIS OPEN FORUM:     TBD
 
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STATEMENT OF THE ISSUE:  There are two errors in the IBIS version 2.1 
specification regarding monotonicity.  During the meeting on 10-7-94 the 
IBIS forum agreed to change the specification to correct these errors.
 
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STATEMENT OF THE RESOLVED SPECIFICATIONS:
The following changes apply to version 2.1 of the specification and IBIS_CHK 
program.
 
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Change 1- Delete the note about 'non-monotonic in one axis' 
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In the section defining the keywords [Pulldown], [Pullup], [GND Clamp], 
[POWER Clamp] and following the paragraph titled "Monotonicity Requirements" 
the following note is present:
 
|                Note that the above conditions allow the data to be 
|                non-monotonic in one axis.
 
The above two lines shall be deleted from the specification.
 
 
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Change 2- Add two paragraphs from BIRD 8.2 
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Add the following two paragraphs where the sentence from change 1 above
is removed.  This is not an error or even a warning.  It was down-graded 
to a simple NOTE: in BIRD 8.2
 
*
*               The IBIS_CHK program will test for non-monotonic data and
*               provide a maximum of one note per V/I table if non-montonic 
*               data is found.   For example:
*                "NOTE: Line 300, Pulldown V/I table for model DC040403 is 
*                 non-monotonic!  Most simulators will filter this data
*                 to remove the non-monotonic data." 
*
*               It is also recognized that the some data may be monotonic if 
*               currents from both the output stage and the clamp diode are
*               added together as most simulators do.  To limit the complexity 
*               of the version 2.0 IBIS_CHK program, it will consider only one 
*               V/I table at a time monotonicity testing.
 
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ANALYSIS PATH/DATA THAT LED TO SPECIFICATION: The problems were discovered while
the new IBIS_CHK V2.x program was being written.  The problems were reported
to the IBIS forum at the 10-7-94 meeting by Arpad of Intel.
 
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ANY OTHER BACKGROUND INFORMATION:
Bird 8.2 address's this issue.