IBIS - EIA IBIS Open Forum Activity: RE: [IBIS] problem with dv/

From: Syed Huq <shuq@cisco.com>
Date: Wed Dec 15 2004 - 10:32:11 PST

Hi,

The default Tr/Tf is [Sim time]/100. That is if Tr and Tf are not
defined by the user.

- Syed

<extracted from ./doc/s2ibis2.txt
---------------------------------------------------------------
   [Tr] t_typ t_min t_max

        t_typ = stimulus input voltage risetime for TYP curves
        t_min = stimulus input voltage risetime for MIN curves
        t_max = stimulus input voltage risetime for MAX curves

        Optional.
        Default: [Sim time] / 100.

        Describes the stimulus input voltage risetime.

    [Tf] t_typ t_min t_max

        t_typ = stimulus input voltage falltime for TYP curves
        t_min = stimulus input voltage falltime for MIN curves
        t_max = stimulus input voltage falltime for MAX curves

        Optional.
        Default: [Sim time] / 100.

        Describes the stimulus input voltage falltime.
------------------------------------------------------------------------

attached mail follows:

hi,

that right. But in my case i reduced it from 20ns to 2ns( which i think is
unrealistic in terms of simulation). But it was still -ve.
dv/dt came to abt 0.15/-0.5000p.

But then after dng this i changed the default Tr and Tf values.
I made [Tr] 1ns 1ns 1ns
[Tf] 1ns 1ns 1ns

It now works fine. I get +ve values.

Now , can anyone tell me how are these two parameters (Tr and Sim Time) related
?

-- Vivek

                      sanjay.bobe@wipro
                      .com To: Vivek.Kumar.Sundriyal@nsc.com, ibis@eda.org
                      Sent by: cc:
                      owner-ibis@eda.or Subject: RE: [IBIS] problem with dv/dt
                      g


                      12/15/04 02:18 PM

Hi,

Reducing simulation time will solve the negative dv/dt problem.

Regards
Sanjay

-----Original Message-----
From: owner-ibis@eda.org [mailto:owner-ibis@eda.org] On Behalf Of Vivek
Kumar Sundriyal
Sent: Wednesday, December 15, 2004 2:18 PM
To: ibis@eda.org
Subject: [IBIS] problem with dv/dt

Hi ,

I am using s2ibis2 for solaris.

While generating the curves, i find a problem with the [Rising
Waveform] and [Falling waveform]

The dv/dt_r gives me values like 0.15/-40.000p.
And the dv/dt_f also gives me 0.15/-40.000p.

What can be the potential cause of the problem ?

Also i dont seem to undersand the some concepts behind the generation
of the IBIS models. Can anyone suggest me any material/text book/link
which can help me with a complete theory of the IBIS model generation
process ?

I have downloaded s2ibis2 for solaris from the website. Does the source
code need any modifications before i use them for real test cases ?

Any help will be appreciated.

Thx,
Vivek

-----------------------------------------------------------------
|For help or to subscribe/unsubscribe, email majordomo@eda.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 email a request to ibis-request@eda.org.
|
|IBIS reflector archives exist under:
|
| http://www.eda.org/pub/ibis/email_archive/ Recent
| http://www.eda.org/pub/ibis/users_archive/ Recent
| http://www.eda.org/pub/ibis/email/ E-mail since 1993

Confidentiality Notice

The information contained in this electronic message and any attachments to this
message are intended
for the exclusive use of the addressee(s) and may contain confidential or
privileged information. If
you are not the intended recipient, please notify the sender at Wipro or
Mailadmin@wipro.com immediately
and destroy all copies of this message and any attachments.

-----------------------------------------------------------------
|For help or to subscribe/unsubscribe, email majordomo@eda.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 email a request to ibis-request@eda.org.
|
|IBIS reflector archives exist under:
|
| http://www.eda.org/pub/ibis/email_archive/ Recent
| http://www.eda.org/pub/ibis/users_archive/ Recent
| http://www.eda.org/pub/ibis/email/ E-mail since 1993

This archive was generated by hypermail 2.1.8 : Wed Dec 15 2004 - 10:33:48 PST