[ibis-macro] Re: BIRD 158.3
- From: "Muranyi, Arpad" <Arpad_Muranyi@xxxxxxxxxx>
- To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
- Date: Fri, 24 May 2013 14:03:15 +0000
Walter,
Here are my comments on this BIRD draft.
What does "differential transmission" mean in this sentence:
"This Impulse Response characterizes the differential transmission of the Tx
analog buffer model,"?
Could you make this clearer with better wording?
In the following sentence you are talking about the "die side
of the package":
"For a Tx buffer, the Transmitter Circuit defines the analog buffer model
between the zero impedance stimulus input voltage source and the die side of
the package model. For an Rx buffer, the Receiver Circuit defines the analog
buffer model between the die side of the package model and a high impedance
probe at the input to the Rx Algorithmic model."
However, it is not clear whether this means that the buffer model
described by the data in the Touchstone file can/should also
include the on-die interconnect or not. I think this should
be clearly stated otherwise different people will make different
assumptions to model on-die interconnects.
This sentence:
"Note that this Touchstone analog model only represent the on-die model between
the die pad and buffer interface to the algorithmic model"
is somewhat misleading, because it can be interpreted as if the
Touchstone model is **the** on-die interconnect model between the
pad and the buffer's terminals ("buffer interface").
You use the words "unit excitation". This sentence:
"This BIRD defines what that unit excitation is when the Tsonefile parameter is
present."
really doesn't make sense, because by definition a unit = 1,
i.e. the "unit excitation" would have to have a fixed and
predefined magnitude of 1 volt, yet in this BIRD you define
Tx_Voh and Tx_Vol, which is not "unit" anymore. Also, please
correct the spelling of "Tsonefile" in this sentence (missing
"t").
You mention in the discussion of the Impulse Response generation
that the Tstonefile parameter is a Reserved Parameter, but you
don't say anywhere in the document whether the rest of the parameters
in this BIRD are Reserved or Model_Specific. Please specify what
you want them to be.
I would also like to request to put a "0" before and after each
decimal point for properness. For example, instead of "(Range 1. .5 1.)"
please write "(Range 1.0 0.5 1.0)", it is much more readable that way...
Thanks,
Arpad
======================================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]
On Behalf Of Walter Katz
Sent: Thursday, May 23, 2013 9:04 PM
To: IBIS-ATM
Subject: [ibis-macro] BIRD 158.3
All,
Please review version 158.3 (Tstonefile AMI models) before I send the final
version to Michael tomorrow afternoon.
The major change is that there are now two Tx voltage levels (Tx_Vol and
Tx_Voh) that determine the differential step response stimulus that is assumed
for generating the Impulse Response of the channel. This make BIRD158
Tstonefile models directly convertible to BIRD 160 external models, and gives
the model maker the ability to determine the common mode voltage when
generating the Impulse Response of a channel.
Walter
Walter Katz
wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 303.335-6156
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