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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:
   Found in IBISCHK3 V3.2.7

PLATFORM (SPARC, HP700, PC, etc.):
   Sun Ultra 10

OS AND VERSION:
   Unix Sun Solaris 5.

REPORTED BY: Bob Ross, Mentor Graphics

DATE: June 15, 2001

DESCRIPTION OF BUG:
   Non-Monotonic I-V Table Causes Waveform End Point Test to Fail

INSERT IBIS FILE DEMONSTRATING THE BUG:

|**************************************************************************
[IBIS Ver]      3.2
[File name]     bug57.ibs
[File rev]      0.1
[Date]          June 15, 2001
|**************************************************************************
[Component]     BUG57
[Manufacturer]  Sample
[Package]       
|               typ             min             max
R_pkg           0     NA NA    
L_pkg           0     NA NA          
C_pkg           0     NA NA           
|***************************************************************************
[Pin]  signal_name      model_name         R_pin       L_pin     C_pin
|
1  test     out_bad
|
|***************************************************************************
[Model]        out_bad
Model_type     Output
Vmeas = 2.5
Vref = 0
Cref = 5.00pF
C_comp           0   NA NA
[Voltage Range]  5.0 NA NA
|***************************************************************************
[Pulldown]
|*** Commenting this line out gives 0 errors and warnings
-5.1   -50ma    NA NA
|***
-5    -100ma    NA NA
0      0        NA NA
10     200ma    NA NA
[Pullup]
|*** And commenting this line out gives 0 errors and warnings
-5.1   50ma     NA NA
|***
-5     100ma    NA NA
0      0        NA NA
10    -200ma    NA NA
|
|***************************************************************************
[Ramp]
dV/dt_r      1.5/.6n NA NA
dV/dt_f      1.5/.6n NA NA
|***************************************************************************
[Falling Waveform]
V_fixture = 5V
R_fixture = 50.00Ohm
0  5   NA NA
1  2.5 NA NA
[Rising Waveform]
V_fixture = 5V
R_fixture = 50.00Ohm
0  2.5 NA NA
1  5   NA NA
[Rising Waveform]
V_fixture = 0.000V
R_fixture = 50.00Ohm
0  0   NA NA
1  2.5 NA NA
[Falling Waveform]
V_fixture = 0.000V
R_fixture = 50.00Ohm
0  2.5 NA NA
1  0   NA NA
|***************************************************************************
[End]

Four Errors are produced.  An example is below

ERROR - Model out_bad: The [Falling Waveform] 
      with [R_fixture]=50 Ohms and [V_fixture]=0V
      has TYP column DC endpoints of  0.00V and  2.50v, but
      an equivalent load applied to the model's I-V tables yields
      different voltages (-5.42V and  2.50V),
      a difference of -100.00% and  0.00%, respectively.

The calculated end point of -5.42 is wrong because of the non-monotonic
data.

When the non-monotonic points are commented out, 0 Errors are produced.

The testing routine should check matching voltages starting at the middle
of the I-V tables.  Some EDA tools will accept such a model.  

The options are (1) fix the text, (2) reduce Error to Warning - so tools
that accept it will work, or (3) accept this as a failure - and reject the
model if the ibischk3 parser is used for the parsing.

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******************** BELOW FOR ADMINISTRATION AND TRACKING *******************
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BUG NUMBER:  57

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

PRIORITY: [HIGH, MEDIUM, LOW]                               LOW

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

FIXED VERSION: 3.2.9

FIXED DATE:    July 12, 2002

NOTES ON BUG FIX: Classified at the July 20, 2001 Meeting.
                  Will investigate a fix as a low priority project.  If
                  a fix is too costly, may opt for just accepting this
                  bug and clarifying in the Error Message that the file
                  may need to be modified.

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