Subject: BIRD 7

From: Kellee Crisafulli <[email-masked]>
Date: 20 Jan 94 03:56:43 EST

From: Kellee Crisafulli, HyperLynx

Re: BIRD 7

Bob, I basically like what you have proposed in BIRD 7 for the additional 
key words.  I have been going to send in a bird on this, but have been 
waiting for the results of an in-house project we are doing to develop some 
ABT models under IBIS.   We have nearly completed this project and I can 
report on this now.    I also have a few concerns with bird 7, 
specifically:

 1) I believe we absolutely must address the dv/dt issue for the turn off 
side.  We could do this by simply    stating explicitly in the 
specification that the dv/dt associated with opposite side is used as the 
turn-off         time of the open-side device.   However it must include a 
load specification during turn off.And specify this being valid for the a 
50 ohm pull to the opposite rail.

 2) I think it would be very useful to most semi-conductor companies 
developing models to require that      V/I table data match the model type 
exactly.  This way the IBIS parse can check it and help find errors         
       in manually entered data.

 3) If I am not mistaken CMOS has an open_drain p channel and an open_drain 
n channel device there is                no open_source configuration that 
I know of  unless you consider some of the 3 volt outputs with totem        
        pole type n-channel outputs.   Therefore the key word open_source 
may not be appropriate.  I propose instead that we use just Open_drain to 
indicate either an N channel/P channel, open collector, or open emitter 
type output.  The thing that differentiates them is simply the missing V/I 
data for the output.

HyperLynx now has IBIS simulations running of ABT buffers (FutureBus) which 
look pretty good.  These require the open_drain model type and have an 
additional offset for the output diode.  I therefore feel good about