****************************************************************************** ********************* 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 IBISCHK3 V3.2.9 built for Windows 2000 PLATFORM (SPARC, HP700, PC, etc.): PC OS AND VERSION: Windows 2000 REPORTED BY: Randon K Richards and Arpad Muranyi, Intel Corp., Bob Haller, Signal Integrity Software, Formatted by Bob Ross, Teraspeed Consulting Group DATE: November 5, 2003 DESCRIPTION OF BUG: Small Voltage Step around 0 V causes false Waveform Mismatch Error: ERROR - Model BUG81: The [Rising Waveform] with [R_fixture]=50 Ohms and [V_fixture]=5V has TYP column DC endpoints of 2.50V and 5.00v, but an equivalent load applied to the model's I-V tables yields different voltages ( 0.00V and 5.00V), a difference of 50.00% and 0.00%, respectively. Commenting one of the lines below or changing the step to 1e-5 V eliminates the error. -1e-6 0 NA NA |****** This Voltage step too small 0 0 NA NA Might be related to BUG68, BUG73 and earlier Bugs. It could be resolved by the corrections of those tests. Apparently the code to test waveform mismatch encounters a voltage limit. A limit of 1e-6 is too large. A small voltage step in any I-V table might cause a false waveform mismatch error INSERT IBIS FILE DEMONSTRATING THE BUG: |************************************************************************ | [IBIS ver] 3.2 [File name] bug81.ibs [File Rev] 0 [Date] 11/5/2003 [Source] Bob Ross [Copyright] None | |************************************************************************ | Component bug81 |************************************************************************ | [Component] bug81 [Manufacturer] None [Package] | variable typ min max R_pkg 0.0m 0.0m 0.0m L_pkg 5.0nH 5.0nH 5.0nH C_pkg 2.0pF 2.0pF 2.0pf | [Pin] signal_name model_name R_pin L_pin C_pin 1 Output BUG81 | |************************************************************************ | Model BUG81 |************************************************************************ | [Model] BUG81 Model_type Output Vmeas = 1.5V Cref = 12.5pF Rref = 1Mohms Vref = 0V C_comp 5pF NA NA | [Voltage Range] 5V 5V 5V | [Pulldown] | voltage I(typ) I(min) I(max) | -5 -100m NA NA -1e-6 0 NA NA |****** This Voltage step too small 0 0 NA NA 10 200m NA NA | [Pullup] | voltage I(typ) I(min) I(max) | -5 100m NA NA 10 -200m NA NA | | [Ramp] | variable typ min max dV/dt_r 1.5/0.6n NA NA dV/dt_f 1.5/0.6n NA NA R_load = 50 | [Rising Waveform] R_fixture = 50 V_fixture = 5.0 | time V(typ) V(min) V(max) | 0.0n 2.5 NA NA 1.0n 5.0 NA NA | | [End] ---- November 14, 2004 Two Additional Tests Replace the [Pulldown] table in the above file with Test 2 and then Test 3. These two additional test cases use data from actual reported problems. |Test 2 | [Pulldown] -5 -100m -100m -100m -811.85060000E-18 757.68042507E-12 -19.99048800E-9 91.97081492E-12 -596.74490000E-18 757.68042507E-12 -19.99048800E-9 391.97081492E-12 -527.35590000E-18 757.68042507E-12 -19.99048800E-9 391.97081492E-12 0.00000000E+0 757.68042507E-12 -19.99048800E-9 391.97081492E-12 10 200m 200m 200m |Test 3 | [Pulldown] -5 -100m -100m -100m -1.10548E-06 -2.26573E-08 +0.00000E+00 -3.18105E-08 -2.03494E-07 +0.00000E+00 +1.60508E-08 -2.75031E-09 -1.18124E-07 +2.14425E-09 +1.75701E-08 +0.00000E+00 10 200m 200m 200m ************************************************************************* ****************************************************************************** ******************** BELOW FOR ADMINISTRATION AND TRACKING ******************* ****************************************************************************** BUG NUMBER: 81 SEVERITY: [FATAL, SEVERE, MODERATE, ANNOYING, ENHANCEMENT] ANNOYING PRIORITY: [HIGH, MEDIUM, LOW] LOW STATUS: [OPEN, CLOSED, WILL NOT FIX, NOT A BUG] CLOSED FIXED VERSION: 4.0 (beta), 4.0.1 FIXED DATE: December 1, 2003 NOTES ON BUG FIX: Classified at the November 14, 2003 IBIS Meeting and planned to be fixed in the next release. November 14, 2003: Two more tests were added to BUG81 based on actual code reports from Randon Richards, Arpad Muranyi and Bob Haller. BUG81 appeared to have a problem related to BUG68, and the prototype solution to BUG68 was used to test the three test cases in BUG81. The solution to BUG68 resolved the BUG81 problems. No further work is required, and BUG81 is expected to be closed when the BUG68 correction is implemented and tested. Checked December 13, 2003 based on fixes for BUG68 and BUG73 - Bob Ross ****************************************************************************** ******************************************************************************