Re: [IBIS-Users] Simulation with VT tables for different load conditions

Hi Sunrendra:

Even though IBIS has syntax to support reactive load elements
(L_fixture, C_fixture, and even L_dut and C_dut) we recommend
not extracting models using these elements. Some tools do not
even support these load elements, and others may support them
by vendor-specfic methods.

However, it is possible to process reactive loads by
accounting for the time-varying reactive path derivatives
within the four V-T methodology. One presentation provides
some details.

   http://www.eda.org/ibis/summits/sep07a/chen.pdf

Bob

Muranyi, Arpad wrote:
> Surendra,
>
> In addition to Tom's comments and my reply to it, I want
> to add a little more to answer some of the other aspects
> of your question.
>
> Some tools support only up to four V-t tables. This may
> be done in a variety of ways, such as picking the first
> four, or picking the first two rising and first two falling
> waveforms from the IBIS [Model]. I do not know which tool
> does what, you need to ask your vendor about their algorithms.
>
> Then there are some other tools which support all of the
> V-t tables in the IBIS [Model], but again I don't know
> what their algorithms are, so you need to ask them to
> understand that.
>
> I can give you an example for how it could be done through
> an experiment I did with a colleague in the following
> presentation (mostly pg. 15 and onwards):
>
> http://www.eda.org/ibis/summits/jun03b/muranyi1.pdf
>
> I hope this helps.
>
> Arpad
> ==============================================================
>
> ------------------------------------------------------------------------
> From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On
> Behalf Of surendra.deshmukh@wipro.com
> Sent: Thursday, September 16, 2010 6:33 AM
> To: ibis-users@eda.org
> Subject: [IBIS-Users] Simulation with VT tables for different load
> conditions
>
> Hi,
>
> The IBIS specification permits up to 100 (VT) waveforms to be
> included to describe buffer transitions, using a variety of loading
> conditions. Can I get the answer how these tables are used during
> simulation for a different load condition?
>
> E.g. If VT tables are generated for C_fixture of 5pf and 10pf
> and simulation has to be done with C_fixture of 8pf then how simulator
> will take these 5pf and 10pf tables for its simulation at 8pf of load?
>
>
>
> Thanks in advance.
>
>
>
> Regards
>
> Surendra.
>
> Please do not print this email unless it is absolutely necessary.
>
> 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 proprietary, confidential or privileged information. If
> you are not the intended recipient, you should not disseminate,
> distribute or copy this e-mail. Please notify the sender immediately and
> destroy all copies of this message and any attachments.
>
> WARNING: Computer viruses can be transmitted via email. The recipient
> should check this email and any attachments for the presence of viruses.
> The company accepts no liability for any damage caused by any virus
> transmitted by this email.
>
> www.wipro.com
>
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner <http://www.mailscanner.info/>, and is
> believed to be clean.
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner <http://www.mailscanner.info/>, and is
> believed to be clean.

-- 
Bob Ross
Teraspeed Consulting Group LLC     Teraspeed Labs
121 North River Drive              13610 SW Harness Lane
Narragansett, RI 02882             Beaverton, OR 97008
401-284-1827                       503-430-1065
http://www.teraspeed.com           503-246-8048 Direct
bob@teraspeed.com
Teraspeed is a registered service mark of Teraspeed Consulting Group LLC
-- 
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