[ibis-macro] Re: IBIS Aggressor_Only Syntax Discussion

From: Walter Katz <wkatz@xxxxxxxxxx>
To: <bob@xxxxxxxxxxxxxxxxx>, "'IBIS-ATM'" <ibis-macro@xxxxxxxxxxxxx>
Date: Mon, 12 Aug 2019 21:05:57 -0400 (EDT)

Bob,

I think the following are contradictory. I always though that you only had
to mark one of the terminals in a connection as Aggressor_Only to make the
connection Aggressor_Only.

On page 36

"Within any Interconnect Model, if a terminal line is identified as
Aggressor_Only, then the corresponding terminal line associated with the
same pin_name shall also be identified as Aggressor_Only."

On page 32 In addition, some

If any *_I/O pin is marked as Aggressor_Only, then any *_I/O pin with the
same pin_name entry shall be considered as an aggressor, and not a victim.

There is nothing illegal about all connections on an interconnect model to
be Aggressor_Only.

The model maker would therefore indicate that connections to the outer
routes' terminals do not include all of their aggressors by adding the
optional argument "Aggressor_Only" to their terminals.

Terminals that include the Aggressor_Only entry may not be suitable to be
simulated as victims, as they do not experience the full coupling present in
the real physical structure.

So if all the connections within a model are Aggressor_Only, the EDA tool
can still to a coupled simulation knowing that there may be addition
crosstalk on all of the connections in the model that is not accounted for
in this model.

It certainly warrants a warning, but not an error.

I do think a BIRD is warranted to rewrite the fpllowing line:

"Within any Interconnect Model, if a terminal line is identified marked as
Aggressor_Only, then the corresponding terminal line associated with the
same pin_name shall also be identified considered as Aggressor_Only."

Walter

Walter Katz

wkatz@xxxxxxxxxx <mailto:wkatz@xxxxxxxxxx>

Office 978.461-0449 x 133

Mobile  720.417-3762

From: ibis-macro-bounce@xxxxxxxxxxxxx <ibis-macro-bounce@xxxxxxxxxxxxx> On
Behalf Of Bob Ross
Sent: Monday, August 12, 2019 6:25 PM
To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
Subject: [ibis-macro] IBIS Aggressor_Only Syntax Discussion

All,

While we had intended to discuss IBIS Version 7.0 Aggressor_Only syntax
rules at the Interconnect Task Group, we also plan to discuss this topic at
the ATM Task Group.   Several key people should be attending at ATM.

The attached rules are for the parser developer to implement and test.

Two questions:

Should having Aggressor_Only on ALL [Interconnect Model] *_/I/O terminals be
an ERROR or WARNING?  (Technically that [Interconnect Model] cannot be
used.)

If an [Interconnect Model] contains an Aggressor_Only terminal line, should
both interfaces with the same pin_name be marked Aggressor_Only?

The verbiage in IBIS Version 7.0 is not clear on page 306, bottom - does
"identified" mean "marked" or "interpreted"?

"Within any Interconnect Model, if a terminal line is identified as
Aggressor_Only, then the corresponding terminal line associated with the
same pin_name shall also be identified as Aggressor_Only."

Bob

--

Bob Ross

Teraspeed Labs

www.teraspeedlabs.com <http://www.teraspeedlabs.com/>

bob@xxxxxxxxxxxxxxxxx <mailto:bob@xxxxxxxxxxxxxxxxx>

Direct: 503-246-8048

Office: 971-279-5325

References:
- [ibis-macro] IBIS Aggressor_Only Syntax Discussion
  - From: Bob Ross

[ibis-macro] Re: IBIS Aggressor_Only Syntax Discussion

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