[ibis-macro] Re: Minutes from the 28 February ibis-atm meeting
- From: "Bob Miller" <dmarc-noreply@xxxxxxxxxxxxx> (Redacted sender "bob.miller" for DMARC)
- To: Curtis Clark <curtis.clark@xxxxxxxxx>
- Date: Mon, 6 Mar 2017 17:30:52 -0700
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> 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>
)
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