Re: [IBIS-Users] How Ramp data is processed ?

Hello Itzik:

One approach is simply to assume a relationship such as

   W(t)pu = 1-W(t)pd

Another approach is to the same R_load to the other rail
and to assume an amplitude adjusted and time scaled V(t)
for that rail.

Both approaches are assumptions and may still not
produce results that correlate with the source data.

Bob

Itzik Peleg wrote:

> Hello IBIS Users
>
> When only ramp data exist in the model.
> As far as I understand the ramp rate is used to calculate the two weight
> functions (one of the pull down and one for the pull up) that describe
> this transition (high to low or low to high).
>
>
> >From Ramp we got the V(t) that describe the transition (linear curve).
> The resistor load is also known R_load.
> We also got the I(V) curves for pullup and pulldown (I will mark this
> function as I(V)pu and I(V)pd).
> I will mark the weight function as W(t)pu for pullup and W(t)pd.
> Then we can write this equation for the transition:
>
> V(t) = R_load* (I(V)pu * W(t)pu - I(V)pd * W(t)pd)
>
> In order to get the W(t)pu and W(t)pd we need one more equation.
> What I am missing here ?
> Can anyone point me to a relevant paper on this subject ?
>
> --
> Regards
>
> Itzik Peleg
> Board Technology Group
>
> Marvell Semiconductor Israel Ltd
> 6 Ha'mada St. Industrial Area
> P.O.Box 692 Yokneam 20692 ISRAEL
> Email - itzik.peleg@il.marvell.com
> Tel - +972 4 9091192
> Cell - +972 54 4452482
> Fax - +972 4 9091501
> WWW Page: http://www.marvell.com
> ========================================================================
> This message may contain confidential, proprietary or legally privileged
> information. The information is intended only for the use of the
> individual or entity named above. If the reader of this message is not
> the intended recipient, you are hereby notified that any dissemination,
> distribution or copying of this communication is strictly prohibited.
> If you have received this communication in error, please notify us
> immediately by telephone, or by e-mail and delete the message from
> your computer.
>
> Thank you!
> ========================================================================
>

-- 
Bob Ross
Teraspeed Consulting Group LLC     Teraspeed Consulting Group LLC
2926 SE Yamhill St.                Device Modeling Division
Portland, OR 97214                 13610 SW Harness Lane
503-239-5536                       Beaverton, OR 97008
http://www.teraspeed.com           503-430-1065
bob@teraspeed.com                  503-246-8048 Direct
|------------------------------------------------------------------
|For help or to subscribe/unsubscribe, email majordomo@eda.org
|with just 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 written 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