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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@eda.org.
A list of reported bugs will be maintained on vhdl.org.
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PARSER VERSION NUMBER:
Found in IBISCHK4 V4.0 Beta built for Windows 2000
PLATFORM (SPARC, HP700, PC, etc.):
PC
OS AND VERSION:
Windows 2000
REPORTED BY: Bob Haller, Signal Integrity Software, Formatted by John Angulo, Mentor Graphics Corp.
DATE: January 23, 2004
DESCRIPTION OF BUG:
IBISCHK4.0 Beta incorrectly reports discrepancies between I-V and V-t table
operating points:
IBISCHK4 V4.0beta
Checking bug82.ibs for IBIS 3.2 Compatibility...
ERROR - Model bug82: The [Rising Waveform]
with [R_fixture]=50 Ohms and [V_fixture_min]=1.8V
has MIN column DC endpoints of 0.60V and 1.80v, but
an equivalent load applied to the model's I-V tables yields
different voltages ( 0.60V and -925596313493178310000000000000000000000000
00000000000000000000.00V),
a difference of 0.00% and 100.00%, respectively.
ERROR - Model bug82: The [Falling Waveform]
with [R_fixture]=50 Ohms and [V_fixture_min]=1.8V
has MIN column DC endpoints of 0.60V and 1.80v, but
an equivalent load applied to the model's I-V tables yields
different voltages ( 0.60V and -925596313493178310000000000000000000000000
00000000000000000000.00V),
a difference of 0.00% and 100.00%, respectively.
WARNING - Model 'bug82': MIN VI curves cannot drive through Vmeas=1.4V
given load Rref=28 Ohms to Vref=1.8V
Errors : 2
Warnings: 1
File Failed
This happens because the function acdc_VI_Given_VIC_VR() in acdc.c improperly
reports the I-V/V-t intersection whenever it lies above the highest voltage in
the I-V characteristic. This defect is likely to show itself in models lacking
clamp tables and in which either the [Pullup] or [Pulldown] table does not cover
the range from -Vcc to 2*Vcc. Any open drain or open source model which lacks
clamp tables is likely to meet these conditions because it is likely to lack
either the [Pullup] or [Pulldown] table. In this test case, IBISCHK generates
error messages only for the MIN data because the highest voltage in the high-
state I-V characteristic for the minimum corner lies below the 1.8 V V-T
operating voltage.
INSERT IBIS FILE DEMONSTRATING THE BUG:
|************************************************************************
|
[IBIS Ver] 3.2
[File Name] bug82.ibs
[File Rev] 1.0
[Date] 1/13/2004
[Source] John Angulo. Derived from the following:
From silicon level SPICE model
Developed by:
Signal Integrity Software, Inc.
6 Clock Tower Place, Suite 250
Maynard, MA 01754
support@sisoft.com
www.sisoft.com
(978) 461-0449
|
[Notes]
[Disclaimer] Not a useful or fully compliant IBIS model, just a test case
[Copyright] none
|
|************************************************************************
| Component bug82
|************************************************************************
|
[Component] bug82
[Manufacturer] none
|
[Package]
| Default pkg params obtained from strip line length=12mm
R_pkg 616m NA NA
L_pkg 3.6nH NA NA
C_pkg 1.44pF NA NA
|
[Pin] signal_name model_name R_pin L_pin C_pin
A2 open_drain bug82
|
|****************************************************************
| Model bug82
|****************************************************************
|
[Model] bug82
Model_type Open_drain
C_comp 228.4f 193.34f 259.58f
Rref = 28
Vref = 1.80
[Model Spec]
Vmeas 1.4V 1.4V 1.4V
|
[Temperature Range] 60 120 -40
[Voltage Range] 1.8 1.692 1.908
[Pulldown]
.0012 0. 0. 0.
.039 .0024 .0024 .0031
.0948 .0058 .0058 .0075
.1505 .0089 .0088 .0114
.2062 .0117 .0117 .0148
.2619 .0141 .0141 .0179
.3177 .0163 .0163 .0205
.3734 .0183 .0184 .0229
.4291 .02 .0201 .0249
.4849 .0216 .0217 .0265
.5406 .0229 .023 .0279
.5963 .0239 .0241 .0289
.652 .0248 .025 .0297
.7078 .0255 .0258 .0302
.7635 .0261 .0264 .0305
.8192 .0264 .0268 .0307
.875 .0267 .0271 .0309
.9307 .0268 .0273 .031
.9864 .0269 .0274 .0311
1.0422 .027 .0275 .0311
1.0979 .0271 .0276 .0311
1.1536 .0271 .0276 .0311
1.2093 .0271 .0276 .0311
1.2651 .0271 .0276 .0312
1.3208 .0271 .0276 .0312
1.3765 .0272 .0277 .0312
1.4323 .0272 .0277 .0312
1.488 .0272 .0277 .0312
1.5437 .0272 .0277 .0312
1.5994 .0272 .0277 .0312
1.6552 .0272 .0277 .0312
1.7109 .0272 .0278 .0312
1.7666 .0272 .0278 .0312
1.8224 .0272 .0278 .0312
1.8781 .0272 .0278 .0312
[Ramp]
dV/dt_r .721/157.74p .7227/193.24p .7928/124.21p
dV/dt_f .721/145.82p .7227/231.23p .7928/82.808p
[Rising Waveform]
R_fixture = 50
V_fixture = 1.8
0. .5982 .5953 .4785
19.975e-9 1.8 1.7999 1.8
[Falling Waveform]
R_fixture = 50
V_fixture = 1.8
0. 1.8 1.7999 1.8
19.975e-9 .5984 .596 .4787
|
|
[END]
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******************** BELOW FOR ADMINISTRATION AND TRACKING *******************
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BUG NUMBER: 82
SEVERITY: [FATAL, SEVERE, MODERATE, ANNOYING, ENHANCEMENT] MODERATE
PRIORITY: [HIGH, MEDIUM, LOW] MEDIUM
STATUS: [OPEN, CLOSED, WILL NOT FIX, NOT A BUG] CLOSED
FIXED VERSION: 4.0.2
FIXED DATE: April 15, 2004
NOTES ON BUG FIX: Classified at the January 30, 2004 IBIS Forum Meeting
To be fixed in the next release via code suggested by
John Angulo. BUG82 was caused as part of the fix to
BUG73.
Fixed in ibischk4.0.2 and validated on April 15, 2004
Fix left out ibischk4.1.0 by mistake. BUG87 Filed to
reinsert Fix (March 23, 2005)
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