Subject: [IBIS-Users] Making Pullup curves VCC relative.
From: John Phillippe (ra6314@email.sps.mot.com)
Date: Tue Oct 15 2002 - 13:05:30 PDT
IBIS Gurus:
The more I try to figure out what the IBIS spec, and Cookbook say
about making the pullup curves VCC relative, the more confused I get.
Here is what I know so far.
Spice2IBIS generates 4 different spice decks for a given process (typ or
min or max) described below:
dutpad.spi - Typ pullup curve (tristated), sweep range: -VCC to 2*VCC
putpad.spi - Typ pullup curve, sweep range: -VCC to 2*VCC
pctpad.spi - Typ power clamp curve, sweep range: VCC to 2*VCC
gctpad.spi - Typ ground clamp curve, sweep range: -VCC to VCC
All of the sweep voltages are referenced to ground. My questions deal
with the post processing by the spice2ibis utility, and what the spec
wants.
For the pullup curve, does spice2ibis subtract the dutpad.spi results
from the putpad.spi results, and then take that data and put it into the
ibis file? Does it do some kind of subtraction from VCC?
If I wanted to create a pullup curve by hand would I only need to
subtract the dutpad (clamp) data from putpad (driver) data? Anyone have
a good/simple explanation of what "VCC relative" means?
Thanks for any and all info.
-- John Phillippe SPS, 32 Bit Embedded Controller Division, IC Creation Motorola - 512-895-1835 Austin, TX - ra6314@email.sps.mot.com |------------------------------------------------------------------ |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
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