All,
Good discussion and more comments or responses for the ATM meeting and
pending BIRD158.6:
1. I would state that a new subsection is proposed: 10.X be added for
IBIS-AMI Analog Buffer Model Parameters
2. The changes should start with an INTRODUCTION to define a term:
This section discusses connections to 4-port analog circuit data file
models described in a Touchstone format and named by a Ts4file parameter.
(note, Ts4file implies a restrictedTouchstone format, but this is never
defined until later. We could read the text to include four-port data in
ibis-iss, vhdl, etc. formats.)
3. Subsection Title TRANSMITTER DRIVER ANALOG CIRCUIT à DRIVER ANALOG
CIRCUIT or à TRANSMITTER ANALOG CIRCUIT
4. In the paragraph beginning with The IBIS AMI flow: specified
according to this BIRD à specified here
5. Subsection Title RECEIVER ANALOG TERMINATION CIRCUIT à RECEIVER
ANALOG CIRCUIT
6. Also, we might need to wait for BIRD186.x regarding terminology and
the added limitations that the quoted file names can include directory paths
per revised naming rules in section 3. (e.g., ../spar/s4p.sp would be
illegal)
7. As in other sections, two Tables should be added for the five new
parameters:
a. General Rules and Allowable Usage for Analogy Circuit Reserved
Parameters
b. Allowable Data Types for Supporting Analog Circuit Reserved
Parameters
Also, it is stated that these parameters do not interact with the
Interconnect Model parameters (in BIRD189.X)
Bob
From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Thursday, May 11, 2017 7:14 PM
To: wkatz@xxxxxxxxxx; michael.mirmak@xxxxxxxxx; IBIS-ATM
Subject: [ibis-macro] Re: Quick questions on BIRD158.5
Mike,
I agree with Walters answers. I would only add that I think we should also
change the terminology
and refrain from using Analog Termination Circuit, because these
Touchstone models are really
buffer models, not terminator models. Our IBIS vocabulary does make a
difference between
buffers and terminators, and using the word termination in this context is
inconsistent and
confusing with that. (I actually had a rather bloody argument about this
with someone, who was
under the impression that these Touchstone models were not buffer models).
Thanks,
Arpad
============================================================================
=
From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Walter Katz
Sent: Thursday, May 11, 2017 8:35 PM
To: michael.mirmak@xxxxxxxxx; IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
Subject: [ibis-macro] Re: Quick questions on BIRD158.5
MM,
Note that when the reserved parameter Ts4file is defined in the AMI model
the Tx or the Rx schematic shown above is to be used in lieu of the analog
buffer model and the package defined in the .ibs file.
Should be
Note that when the reserved parameter Ts4file is defined in the AMI model
the Tx or the Rx schematic shown above is to be used in lieu of the analog
buffer model defined in the .ibs file.
This was decided and agreed to. I think it was an error that and the
package was not removed.
Th paragraph before this explictily excludes the package model (and note the
typolographical and spelling errors in red):
The IBIS AMI flow requires that the EDA tool generates the impulse response
of the the entire analog circuitry from Tx to Rx algotithmic models.
Typically, the Touchstone file data specified according to this BIRD is to
be used for either the Tx analog buffer excluding the Tx package model
and/or the Rx analog buffer model excluding the Rx package model. The
following figure illustrates the entire setup when both Tx and Rx use the
Ts4file parameter.
There are errors in the following paragraph which describes methods to
generate the impulse response:
Given that the Touchstone 4-port model is LTI there are many methods of
generating the impulse response to be used in AMI modeling that will give
the identical result within numerical accuracy of the technique chosen. One
technique commonly used in EDA tool simulation is to generate the step
response by applying a step stimulus and calculating the time derivative of
that step response. When both Tx and Rx Ts4file parameters are present the
step response is measured between the SRC_pos/SRC_neg input and a high
impedance differential probe between Ports 2 and 4 of the Rx 4-port network.
When only one of Tx or Rx .ami files has the Ts4file parameter present then
the other components contribution to the step response (or just the impulse
response) comes from the model details provided under the [Model] keyword
referencing the .ami file without the Ts4file parameter.
Should be:
Given that the Touchstone 4-port model is LTI there are many methods of
generating the impulse response to be used in AMI modeling that will give
the identical result within numerical accuracy of the technique chosen. One
technique commonly used in EDA tool simulation is to generate the impulse
response by applying a step stimulus and calculating the time derivative of
that step response. When both Tx and Rx Ts4file parameters are present the
impulse response is measured between the SRC_pos/SRC_neg input and a high
impedance differential probe between Ports 2 and 4 of the Rx 4-port network.
When only one of Tx or Rx .ami files has the Ts4file parameter present then
the other components contribution to the impulse response comes from the
model details provided under the [Model] keyword referencing the .ami file
without the Ts4file parameter.
Walter
Walter Katz
<mailto:wkatz@xxxxxxxxxx> wkatz@xxxxxxxxxx
Phone 303.449-2308
Mobile 303.335-6156
From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Mirmak, Michael
Sent: Thursday, May 11, 2017 9:18 PM
To: IBIS-ATM (ibis-macro@xxxxxxxxxxxxx) <ibis-macro@xxxxxxxxxxxxx>
Subject: [ibis-macro] Quick questions on BIRD158.5
Sorry for last-minute questions on BIRD158, but I wanted to ensure these
could be addressed during the technical discussion in the Open Forum:
1) The TX and RX Analog Termination Circuit sections its not
immediately clear where in the specification these are supposed to go. It
would help to note the section in which these are to be inserted.
2) In the text, the following phrase is used:
Note that when the reserved parameter Ts4file is defined in the AMI model
the Tx or the Rx schematic shown above is to be used in lieu of the analog
buffer model and the package defined in the .ibs file.
Will the phrase and the package regarding package models be revised or
removed once BIRD189.x is approved?
3) Related to this, the entire sentence should appear *before* the link
setup circuit diagram that immediately precedes it, to prevent reader
confusion.
4) Also related to this, the link setup diagram should be altered to
make the package portion of the User Setup block optional. Otherwise, the
diagram conflicts with the statement regarding the replacement of the
package information in the .ibs file.
5) The last paragraph of the BIRD text to be added to IBIS mentions
step responses vs. impulse responses. As the phrase step response is
never used in IBIS 6.1, and the information supplied applies just as much to
impulse responses, is the entirety of this paragraph needed?
Thank you!
- MM
