RE: [IBIS-Users] V/T Window adjustment

Shiv,

There were a number of discussions back in January about trimming V/T
tables, with Dimitry Eisenshtat presenting the results of an algorithm he
implemented.  The descriptions of the algorithm were pretty detailed; I
suggest you have a look in the archives and see if you find those
discussions useful.

Todd.

Todd Westerhoff
VP, Software Products
SiSoft
6 Clock Tower Place, Suite 250
Maynard, MA  01754
(978) 461-0449 x24
twesterh@sisoft.com
www.sisoft.com
-----Original Message-----
From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf
Of Mandel, Cary
Sent: Tuesday, May 29, 2007 8:51 AM
To: Shiv Harit MATHUR; ibis-users@eda.org; ibis-users@eda.org
Subject: RE: [IBIS-Users] V/T Window adjustment

Hello Shiv,

I suggest that you remove the leading common delay from the VT tables.
If you do treat the MIN, TYP and MAX models independently -- i.e. strip
the leading delay from the MIN, TYP, MAX models independently -- then
you will be able to run the models at a higher frequency.

Cary Mandel
Mentor Graphics. 

-----Original Message-----
From: owner-ibis-users@server.eda.org
[mailto:owner-ibis-users@server.eda.org] On Behalf Of Shiv Harit MATHUR
Sent: 29 May 2007 11:14
To: ibis-users@server.eda.org; ibis-users@server.eda.org
Cc: Shiv Harit MATHUR
Subject: [IBIS-Users] V/T Window adjustment

Hello Experts,

I am trying to model a buffer whose freq of operation is 1.5Ghz (time
period = 666ps).
While extracting the V/T curve for the buffer we need to take up a
window of not less than 800ps to cover all the three waveforms. The
buffer delay in MAX,NOM and MIN CORNERS is 130.31ps, 228.44ps and
424.08ps respectively.

Please find the snapshot view of the rising output waveform "TXP" of the
buffer in three corners, "SB" is the Input data given to the buffer (the
  delay values are almost same for the falling stimuli also)

Now the problem is that if I extract and dump these values in the IBIS
model, the model will certainly fail in the worst and typical cases as
the bit time is 333ps (< V/T window size). Although it will give a good
match only if MAX corner is considered.

Can anybody please suggest, what could be done for this case in order to
model the behaviour of the buffer correctly in all three corners ?

Regards
Shiv Harit Mathur
STMICROELECTRONICS PVT LTD
INDIA

--
This message has been scanned for viruses and dangerous content by
MailScanner, and is believed to be clean.


-- 
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


-- 
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