[ibis-macro] Re: Minutes from the 28 February ibis-atm meeting
- From: Walter Katz <wkatz@xxxxxxxxxx>
- To: <dmarc-noreply@xxxxxxxxxxxxx>, "Curtis Clark" <curtis.clark@xxxxxxxxx>
- Date: Mon, 6 Mar 2017 20:37:51 -0500 (EST)
All,
It is very simple, the model maker can tell the EDA tool one of several ways
what interconnect model goes between the s4p and the pins – in exactly the
same way that they do today when the [Model] is legacy or [External Model].
The IBIS file can (and does) have several flavors of package models and will
have an additional method defined in BIRD 189. As today in all EDA tools
that support broadband package modeling, the user has the choice of using
the IBIS package model or a broadband model supplied externally to the IBIS
model. It is intended (although not required) that BIRD 189 will be the
preferred way of adding these models, but EDA tools are free to support
their existing methods of including these models on the channel. We do not
tell EDA tools that they must use the existing package modeling facilities
in IBIS today. The clear intention of BIRD 189 is to offer a standard way of
defining these broadband models.
Walter
From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Bob Miller ;(Redacted
sender "bob.miller" for DMARC)
Sent: Monday, March 6, 2017 7:31 PM
To: Curtis Clark <curtis.clark@xxxxxxxxx>
Cc: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
Subject: [ibis-macro] Re: Minutes from the 28 February ibis-atm meeting
Regarding the latest draft of BIRD158.4:
#### For discussion: The model maker may want to inform the user and the
EDA tool that the Ts4file includes the package. Then a separate parameter
is needed. Alternatively, the model maker may provide the s4p data of the
package.
Here's my $0.02 (a refinement of my unscripted comments at last IBIS-ATM)
I think we need to be careful here not to over-specify the use of the
termination models. In particular, the termination models may reasonably
incorporate more or less of the complete analog channel model as the
hardware implementation recommends, more or less consistent with the
following:
* The "Ts4file" analog buffer model is best suited for the analog
components
at the Tx/Rx ends of the channel for which a given buffer/corner is matched
to exactly one analog model (Corner is the one thing that we can use to
point to different analog models)
* Separately-provided (s4p) models concatenated by the user into the
channel
are best for components which may differ from application to application,
e.g. different package options, different buffers driving through corner vs.
side pins on the same multi-channel ASIC/ASSP package, differing on-die
routing for different buffers in a less-than -rigorously-matched die
arrangement, etc.
So the Tx or Rx Ts4file analog model can reasonably include everything from
the buffer termination outward until we reach stuff for which the model
maker cannot provide a single trio of Corner-linked files for. Beyond that
point it is better for a library of s4p models be provided to the user along
with instructions (which I think quickly elaborates well beyond our ability
to standardize) of how the user add these models into their channel model(s)
in their EDA tool of choice's schematic capture cockpit. I don't think we in
IBIS-ATM can/should say exactly where the boundary between the "Ts4file" and
other separately-provided s4p files intended for
IC-or-subsystem-vendor-enlightened selection and concatenation into the
channel model should be drawn (e.g "die bumps" "package pin" "on-die buffer
terminals", "line card connector").
Note my use of the qualifiers "may", "think", etc. I am open to correction
;-)
Regards,
Bob
On Mon, Mar 6, 2017 at 4:07 PM, Curtis Clark <curtis.clark@xxxxxxxxx
<
mailto:curtis.clark@xxxxxxxxx> > wrote:
Minutes from the 28 February ibis-atm meeting are attached.
The following document, which was discussed during the meeting, has been
posted to the work archive.
DATE
AUTHOR <
http://ibis.org/atm_wip/archive-author.html>
ORGANIZATION <
http://ibis.org/atm_wip/archive-org.html>
TITLE <
http://ibis.org/atm_wip/archive-title.html>
FORMATS
28-FEB-2017
Radek Biernacki
Keysight Technologies
BIRD 158.4 AMI Touchstonefile Analog Buffer Models draft 2
(zip
<
http://ibis.org/atm_wip/archive/20170228/radekbiernacki/BIRD_158_4_AMI_Touchstonefile_Analog_Buffer_Models_draft_2.zip>
)(docx
<
http://ibis.org/atm_wip/archive/20170228/radekbiernacki/BIRD%20158.4%20AMI%20Touchstonefile%20Analog%20Buffer%20Models%20draft%202/bird158.4_draft2.docx>
)
Other related posts:
