Subject: [IBIS] updated BUG74
From: Gregory R Edlund (gedlund@us.ibm.com)
Date: Fri Dec 13 2002 - 10:25:17 PST
I updated BUG74 to address the concerns we discussed at the meeting today.
My comments are attached to the end of the bug report.
Greg Edlund
Senior Engineer
Signal Integrity
IBM Engineering and Technology Services
3605 Hwy. 52 N, Dept. HDC
Rochester, MN 55901
gedlund@us.ibm.com
******************************************************************************
********************* 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@vhdl.org.
A list of reported bugs will be maintained on vhdl.org.
******************************************************************************
PARSER VERSION NUMBER:
IBISCHK3 V3.2.5
PLATFORM (SPARC, HP700, PC, etc.):
RS/6000
OS AND VERSION:
aix 3 4 000563044C00
REPORTED BY:
Greg Edlund
DATE:
26 Aug 2002 original report
DESCRIPTION OF BUG:
IBIS parser should issue a warning message when no timing test load is
defined since this is critical for system-level timing.
Valid combinations of Vref, Rref, Cref, and Vmeas should be as follows
(ie no warning messages if these combinations are defined):
1) Vmeas, Cref
2) Vmeas, Vref, Rref
3) Vmeas, Vref, Rref, Cref
All other 13 (2^4 - 3) cases should generate warnings as follows:
Missing Vmeas -> Warning
Rref with no Vref -> Warning
Vref with no Rref -> Warning
No timing test load defined -> Warning
(i.e. no valid timing test load from 1-3 above)
(REVISED ERROR MESSAGES FOR REVISED FILE)
IBISCHK3 V3.2.5
Checking bug74.ibs for IBIS 3.2 Compatibility...
WARNING (line xxx) - timing test load missing.
Errors : 0
Warnings: 1
File Passed
INSERT IBIS FILE DEMONSTRATING THE BUG:
[IBIS Ver] 3.2
[File Name] bug74.ibs
[File Rev] 1.0
[Date] 08/27/02
[Source] None.
[Notes] None.
[Disclaimer] None.
[Copyright] None.
|
[Component] None.
[Manufacturer] None.
[Package]
|
| variable typ min max
|
R_pkg 1.0m NA NA
L_pkg 0.01nH NA NA
C_pkg 0.01pF NA NA
|
[Pin] signal_name model_name R_pin L_pin C_pin
|
1 inout bcmos 1.0m 0.01nH 0.01pF
|-----------------------------------------------------------------------------
| buf_io model definition
|-----------------------------------------------------------------------------
[Model] bcmos
Model_type I/O
Polarity Non-Inverting
Enable Active-High
Vinl = 1.15V
Vinh = 1.35V
| *** PROBLEM AREA: standard load subparameters are missing.
|Vmeas = 1.25V
|Cref = 10pF
|Rref = 1000
|Vref = 0
| ***
| typ min max
|
C_comp 1.15pF 1.15pF 1.15pF
[Temperature Range] 55.0 85.0 25.0
[Voltage Range] 2.50V 2.375V 2.625V
[Ramp]
| typ min max
|
dV/dt_r 0.836/0.405n 0.723/0.456n 0.958/0.358n
dV/dt_f 0.834/0.389n 0.744/0.470n 0.930/0.340n
R_load = 50
[Pulldown]
|
| voltage I(typ) I(min) I(max)
|
-1.0000e+00 -5.0000e-01 -5.0000e-01 -5.0000e-01
5.5511e-17 0.0000e+00 0.0000e+00 0.0000e+00
5.0000e+00 5.0000e-01 5.0000e-01 5.0000e-01
[Pullup]
|
| voltage I(typ) I(min) I(max)
|
-1.0000e+00 5.0000e-01 5.0000e-01 5.0000e-01
0.0000e+00 0.0000e+00 6.1169e-06 7.5391e-06
5.0000e+00 -5.0000e-01 -5.0000e-01 -4.6674e-02
|
[End]
******************************************************************************
******************** BELOW FOR ADMINISTRATION AND TRACKING
*******************
******************************************************************************
BUG NUMBER: 74
SEVERITY: [FATAL, SEVERE, MODERATE, ANNOYING, ENHANCEMENT] ANNOYING
PRIORITY: [HIGH, MEDIUM, LOW] MEDIUM
STATUS: [OPEN, CLOSED, WILL NOT FIX, NOT A BUG] OPEN
FIXED VERSION:
FIXED DATE:
NOTES ON BUG FIX: Classified at the September 20, 2002 IBIS Meeting.
Greg Edlund needs to be more specific regarding the
conditions under which the proposed Warnings are issued
with respect to:
Implied defaults Cref=0, Vref=0, Rref=infinity
Model_types (I/0*, Output*, 3-state*, Open*
Possible Rref value needed for Open*
Mention that [Model Spec] may contain the parameters
and needs to be part of the check, if it exists
We may then discuss the proposed reports with respect to
these details. (Note, the IBIS Spec does not list
defaults).
Added by Greg Edlund on 12/13/02:
Here are my responses. I don't know how to format the table or in which
part of the bug report it belongs - perhaps under "description of bug."
1. Implied defaults Cref=0, Vref=0, Rref=infinity
I don't think this belongs in the error message because it is tool
specific. Each tool vendor must decide on the default value of these
parameters.
2. Model_types (I/0*, Output*, 3-state*, Open*
Covered by table below.
3. Possible Rref value needed for Open*
Covered by table below.
4. Mention that [Model Spec] may contain the parameters and needs to be
part of the check, if it exists.
As I read the IBIS spec, the Vmeas subparameter defined under the
[Model Spec] keyword pertains to input timing thresholds, whereas
BUG74 pertains to output timing test loads. These are two different
things; therefore the bug fix can ignore the Vmeas subparameter when
it occurs under the [Model Spec] keyword.
Vmeas Rref/Vref
Required Required
-------- --------
Input NO NO
I/O YES NO
I/O_open_drain YES YES
I/O_open_sink YES YES
I/O_open_source YES YES
Input_ECL NO NO
I/O_ECL YES YES
Terminator NO NO
Output YES NO
3-state YES NO
Open_sink YES YES
Open_drain YES YES
Open_source YES YES
Input_ECL NO NO
Output_ECL YES YES
I/O_ECL YES YES
3-state_ECL YES YES
Series NO NO
Series_switch NO NO
******************************************************************************
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