****************************************************************************** ********************* 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 ibis-bug@eda.org. A list of reported bugs will be maintained on eda.org. ****************************************************************************** PARSER VERSION NUMBER: v4.1.1 PLATFORM (SPARC, HP700, PC, etc.): PC OS AND VERSION: Windows XP REPORTED BY: John Angulo, Mentor Graphics Corp. DATE: 10/26/05 DESCRIPTION OF BUG: IBIS model types with open drain or open source topologies should not have non-zero currents in both [Pullup] and [Pulldown] I-V tables. If they do, ibischk issues a warning message. However, it goes on to check I-V/V-t endpoint agreement using all I-V tables available. In effect, this almost sanctions the simultaneous use of both [Pullup] and [Pulldown] tables in open_* topologies. The client SI tool would have to implement its own I-V/V-t endpoint checks without the inappropriate table to find an I-V/V-t mismatch. The warning message for non-zero [Pullup] currents in open drain topologies and non-zero [Pulldown] currents in open source topologies is easy to ignore. Changing it to an error message would force model makers and users to address the problem. The inappropriate I-V table may describe buffer circuit elements expected to behave statically, which belong instead in one of the clamp I-V tables. INSERT IBIS FILE DEMONSTRATING THE BUG: [IBIS Ver] 2.1 [Comment char] |_char [File name] bugxx.ibs [File Rev] 1.0 [Date] 10/28/05 [Source] John Angulo [Notes] Demonstrates I-V table in conflict with model type [Disclaimer] none |---------------------------------------------------------- [Component] test [Manufacturer] none [Package] R_pkg 0 0 0 L_pkg 0 0 0 C_pkg 0 0 0 [Pin] signal_name model_name R_pin L_pin C_pin 1 io io |---------------------------------------------------------- [Model] io Model_type Open_drain Vmeas = 2.5 Vinl = 2 Vinh = 3 C_comp 0 0 0 [Voltage range] 5 5 5 [Pulldown] -2.5 -5m -5m -5m 0 0 0 0 5 10m 10m 10m [Pullup] -2.5 5m 5m 5m 0 0 0 0 5 -10m -10m -10m [Rising Waveform] R_fixture = 2000 V_fixture = 0 0ns 0 0 0 2ns 2 3 1 4ns 4 3.5 2.5 6ns 4 4 4 [Falling Waveform] R_fixture = 2000 V_fixture = 0 0ns 4 4 4 2ns 2 1 3 5ns 1 0.5 1.5 8ns 0 0 0 [Ramp] dV/dt_r 1.0/1.0n 1.0/1.0n 1.0/1.0n dV/dt_f 1.0/1.0n 1.0/1.0n 1.0/1.0n R_load=1000 [End] ****************************************************************************** ******************** BELOW FOR ADMINISTRATION AND TRACKING ******************* ****************************************************************************** BUG NUMBER: 91 SEVERITY: [FATAL, SEVERE, MODERATE, ANNOYING, ENHANCEMENT] ENHANCEMENT PRIORITY: [HIGH, MEDIUM, LOW] LOW STATUS: [OPEN, CLOSED, WILL NOT FIX, NOT A BUG] CLOSED FIXED VERSION: Version 4.2.1 FIXED DATE: March 31, 2007 NOTES ON BUG FIX: Classified at the November 18, 2005 meeting, with the resolution that the Warning message be changed to an Error. (The minutes mention Enhancement, but not the priority. To be fixed in the next release. Checked April 12, 2007 This fix applies to Version 2.1, 3.2 and 4.2 files. ****************************************************************************** ******************************************************************************