Fabio,
The input to [External Model] comes from the EDA tool. This is the stimulus
signal.
The output of [External Model] (and the power supplies) are connected to the
pads.
You can write a model between these terminals as you wish. But you cannot put
another [Model] with I-V curves in series with that [External Model]. The
[External
Model] replaces the I-V curves in the [Model].
There is a similar limitation in IBIS with [External Circuit]. You can use
them for buffer
modeling, and you can even put multiples of them in series, but you cannot put
them
in series with [Model] (or [External Model]).
As a result, if you want to include predriver logic in your model, you will end
up having
to implement your own I-V curve algorithm for the output stage too. This is
doable,
but needs more work.
I hope this helps,
Arpad
===================================================================
From: Fabio BRINA [mailto:fabio.brina@xxxxxx]
Sent: Monday, May 22, 2017 11:43 AM
To: Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>; ibis@xxxxxxxxxxxxx;
ibis-users@xxxxxxxxxxxxx
Subject: RE: External Logic core (VerilogA)
Thank you Arpad,
yes this answers, but on other side for me is not so clear which are
the logic limitations of the [External Model] . the web doesn't help a
lot.
Regards,
Fabio
From: Muranyi, Arpad [mailto:Arpad_Muranyi@xxxxxxxxxx]
Sent: Friday, May 19, 2017 8:33 PM
To: Fabio BRINA <fabio.brina@xxxxxx<mailto:fabio.brina@xxxxxx>>;
ibis@xxxxxxxxxxxxx<mailto:ibis@xxxxxxxxxxxxx>;
ibis-users@xxxxxxxxxxxxx<mailto:ibis-users@xxxxxxxxxxxxx>
Subject: RE: External Logic core (VerilogA)
Fabio,
The [External Model] keyword in IBIS allows you to replace the legacy I-V / V-t
curve
based [Model] with whatever you write on your own for [External Model], but you
can't
use the content of [External Model] and combine it with the I-V / V-t curve
based [Model].
I hope this answers your question.
Thanks,
Arpad
=======================================================================
From: ibis-bounce@xxxxxxxxxxxxx<mailto:ibis-bounce@xxxxxxxxxxxxx>
[mailto:ibis-bounce@xxxxxxxxxxxxx] On Behalf Of Fabio BRINA
Sent: Friday, May 19, 2017 7:23 AM
To: ibis@xxxxxxxxxxxxx<mailto:ibis@xxxxxxxxxxxxx>;
ibis-users@xxxxxxxxxxxxx<mailto:ibis-users@xxxxxxxxxxxxx>
Subject: [ibis] External Logic core (VerilogA)
Hello ibis experts,
I have a Driver described with IBIS model, then I have the Logic core of
my device
that I described in VerilogA language. The Outputs of this VerilogA
are analog ideal voltage signals ( transition (vout, tdalay, trise, tfall) )
Can I use the [External Model] keyword to connect the Logic (verilogA) with
the input of my Driver (IBIS) ?
I want , in same way, to include the Logic core into the IBIS model. Is this
possible?
There are any examples of that?
Thank you,
Regards,
Fabio
