BIRD 7

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
Received on Thu Jan 20 01:02:06 1994