Subject: Re:

From: [email-masked]
Date: Mon, 20 Mar 2000 11:48:10 +0200

Hi Everybody!

It came to my mind, that how does simulation with IBIS models take into
account 
parasitics which comes from power supply and ground pins and bonding wires?
As I understand only signal line's pin and bonding parasitics are included
into the simulation.
However, I think that in real life parasitics from power supply and ground
bonding wires has some effect also.

My current opinion is that effect from power supply and ground bonding wires
are not taken into account. Connection to power supply and ground are
considered ideal.
Am I right?

I tried to find information about this from IBIS specifications, but I
couldn't find any. 

What is Your opinion, how (much) does this effect to the correctness of the
simulation result? 

Best Regards,
                    Janne Ikavalko

-- Janne Ikavalko 
-- NMP Tampere, Finland
-- GSM +358 50 3655120
-- [email-masked]

---

From: Mike LaBonte <[email-masked]>
Date: Mon, 20 Mar 2000 08:42:09 -0500

Janne,

Let us separate the power and ground parasitics into 3 categories:

- package parasitics
- bond wire parasitics
- on-die interconnect parasitics

IBIS has multiple methods for handling package parasitics. One of them, the
[Define Package Model] section, can include bond wire parasitics. There is no
good solution for on-die interconnect yet, but the IBIS committee has begun
considering this. The summary is that a good portion of the path from power
and ground pins to the buffers they supply is covered by IBIS, but not all of it.

I would expect that most, if not all, IBIS simulators will use the power and
ground parasitic information if it is present in an IBIS file.

Mike LaBonte