****************************************************************************** ********************* IBIS GOLDEN PARSER BUG REPORT FORM ********************* ****************************************************************************** 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. ****************************************************************************** PARSER VERSION NUMBER: Found in IBISCHK4 V4.1.0 PLATFORM (SPARC, HP700, PC, etc.): PC, Sun OS AND VERSION: Windows 2000, Sun_5 REPORTED BY: Bob Ross, Teraspeed Consulting Group, Doran David, Toshiba DATE: March 23, 2005 DESCRIPTION OF BUG: --- The BUG82 fix was not inserted in the ibischk4.1.0 release. BUG87 is to document reinserting the BUG82 fix in the next release. BUG82 was originally filed by Bob Haller, Signal Integrity Software Formatted by John Angulo, Mentor Graphics Corp. ---- 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] bug87.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 bug87 |************************************************************************ | [Component] bug87 [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 bug87 | |**************************************************************** | Model bug87 |**************************************************************** | [Model] bug87 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] ************************************************************************* ****************************************************************************** ******************** BELOW FOR ADMINISTRATION AND TRACKING ******************* ****************************************************************************** BUG NUMBER: 87 SEVERITY: [FATAL, SEVERE, MODERATE, ANNOYING, ENHANCEMENT] MODERATE PRIORITY: [HIGH, MEDIUM, LOW] HIGH STATUS: [OPEN, CLOSED, WILL NOT FIX, NOT A BUG] CLOSED FIXED VERSION: 4.1.1 FIXED DATE: April 10, 2005 NOTES ON BUG FIX: Classified at the April 1, 2005 IBIS Meeting. To be fixed in the Version 4.1.1 release. ****************************************************************************** ******************************************************************************