Date: Thu Aug 04 2011 - 15:28:40 PDT
I want to simulate the ringing behavior found in following signal in
IBIS. This snapshot is from the spice simulation.
(logic high - 3.3v ; logic low - ringing between 2.65 - 2.75v)
The ibis simulation yields the following waveform
The logic low's ringing is not captured in IBIS.
I tried changing the numerical algorithm from TRAP to GEAR in spice
simulation to make sure it is not a numerical artifact. The following
are the rising and falling tables
|
[Rising Waveform]
R_fixture = 50
V_fixture = 3.3
|
| Time V(typ) V(min)
V(max)
|
0 2.72122 NA
NA
8.3554p 2.72933 NA
NA
66.4303p 3.0285 NA
NA
0.109129n 3.15831 NA
NA
0.130693n 3.19638 NA
NA
0.160088n 3.23045 NA
NA
0.204145n 3.25956 NA
NA
0.263155n 3.27863 NA
NA
0.494298n 3.29621 NA
NA
31.25n 3.29998 NA
NA
|
[Falling Waveform]
R_fixture = 50
V_fixture = 3.3
|
| Time V(typ) V(min)
V(max)
|
0 3.30001 NA
NA
77.4596p 3.2744 NA
NA
0.142103n 2.91665 NA
NA
0.446801n 2.67684 NA
NA
29.4488n 2.65867 NA
NA
29.9943n 2.76514 NA
NA
30.1222n 2.65842 NA
NA
30.668n 2.76505 NA
NA
30.7944n 2.65829 NA
NA
31.25n 2.76182 NA
NA
|
As one can see in the Falling table the waveform cycles between 2.65 and
2.76 but it does not get reflected when the file is simulated.
Any pointers in getting ringing behavior on the ibis simulation would be
helpful.
Is there any setting in the spice file that needs to set? I am using the
following:
+ typ=typ
+ ramp_fwf =1
+ ramp_rwf =1
Thanks
Anand
-- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
--------------------------------------------------------------------
|For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org
|with the appropriate command message(s) in the body:
|
| help
| subscribe ibis <optional e-mail address, if different>
| subscribe ibis-users <optional e-mail address, if different>
| unsubscribe ibis <optional e-mail address, if different>
| unsubscribe ibis-users <optional e-mail address, if different>
|
|or e-mail a request to ibis-request@eda-stds.org.
|
|IBIS reflector archives exist under:
|
| http://www.eda-stds.org/pub/ibis/email_archive/ Recent
| http://www.eda-stds.org/pub/ibis/users_archive/ Recent
| http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993
