[ibis-macro] Re: Jitter Transfer Function
- From: "Dmitriev-Zdorov, Vladimir" <vladimir_dmitriev-zdorov@xxxxxxxxxx>
- To: "msteinb@xxxxxxxxxx" <msteinb@xxxxxxxxxx>, David Banas <DBanas@xxxxxxxxxx>
- Date: Fri, 23 Sep 2011 18:59:41 +0000
I agree with the idea of filtering the jitter spectrum in the models. But then,
it seems logical to require definition of the input jitter spectral density,
too. For example, if we know jitter spectral density at Tx, we can find the
density at Rx input by multiplying it on the channel's modular transfer
function (save for possible interaction between jitter and pattern ISI), and
then apply Rx filter to the resulted spectrum and find spectral density at the
output. Spectral density can be converted into 'sigma' but not into PDF unless
we assume normalization.
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]
On Behalf Of Mike Steinberger
Sent: Friday, September 23, 2011 12:45 PM
To: David Banas
Cc: 'Gregory R Edlund'; 'ibis-macro@xxxxxxxxxxxxx';
'ibis-macro-bounce@xxxxxxxxxxxxx'
Subject: [ibis-macro] Re: Jitter Transfer Function
Dave-
Exactly so.
I'm trying to make sure we focus our attention on those concepts which must be
explicitly addressed in the standard.
Thanks for the clarification.
Mike S.
On 9/23/2011 2:40 PM, David Banas wrote:
Jitter Transfer Function is not relevant to the IBIS discussions. While it's a
well established and extremely useful concept, it refers to an analysis to be
performed in the EDA tool based on existing outputs from a receiver model. For
example, our DesignCon2011 paper presented jitter transfer function results
from QCD. The IBIS-AMI model neither knows nor cares that a jitter transfer
function analysis is being performed.
Hi Mike,
Just so we're clear, we are agreed that a receiver model can apply some
spectral shaping to the jitter that comes into it, either via the incoming data
stream or the reference clock, and that any spectral shaping thusly applied
will have a very real effect on BER; right?
Thanks,
-db
From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx>
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Steinberger
Sent: Friday, September 23, 2011 11:05 AM
To: Gregory R Edlund
Cc: ibis-macro@xxxxxxxxxxxxx<mailto:ibis-macro@xxxxxxxxxxxxx>;
ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx>
Subject: [ibis-macro] Re: Jitter Transfer Function
Greg-
http://www.minicircuits.com/app/VCO15-6.pdf
Offers a treatment of clock spectral phase noise density that appears to be
clear, complete, and rigorous. I don't hope to do as good a job. Use this.
Jitter Transfer Function is not relevant to the IBIS discussions. While it's a
well established and extremely useful concept, it refers to an analysis to be
performed in the EDA tool based on existing outputs from a receiver model. For
example, our DesignCon2011 paper presented jitter transfer function results
from QCD. The IBIS-AMI model neither knows nor cares that a jitter transfer
function analysis is being performed.
Jitter with a specified Jitter Spectral Density is, however, a service that a
model may require from the EDA tool in order to produce accurate results.
Hope this helps.
Mike S.
On 09/23/2011 12:29 PM, Gregory R Edlund wrote:
Mike,
Is this this infamous Project Blue Book? Alien abductions? 8-)
Would you be interested in making a MS Word file with two equations in it for
Jitter Spectrum and Jitter Transfer Function?
Greg Edlund
Senior Engineer
Signal Integrity and System Timing
IBM Systems & Technology Group
3605 Hwy. 52 N Bldg 050-3
Rochester, MN 55901
[Inactive hide details for Mike Steinberger ---09/22/2011 02:14:52
PM---All- I strongly suggest that we be very precise in the
t]Mike Steinberger ---09/22/2011 02:14:52 PM---All- I strongly suggest
that we be very precise in the terminology we use,
From: Mike Steinberger <msteinb@xxxxxxxxxx><mailto:msteinb@xxxxxxxxxx>
To: ibis-macro@xxxxxxxxxxxxx<mailto:ibis-macro@xxxxxxxxxxxxx>
Date: 09/22/2011 02:14 PM
Subject: [ibis-macro] Re: Jitter Transfer Function
Sent by: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx>
________________________________
All-
I strongly suggest that we be very precise in the terminology we use, and so I
offer the following two simplified definitions:
Jitter Spectrum: The frequency domain spectral density of the phase noise on a
clock, as compared to an ideal reference clock. To normalize out the resolution
bandwidth of the measurement equipment, this spectral density is expressed with
respect to the spectral density of the main spectral component: dB Carrier per
root Hz (dbC/root Hz).
Jitter Transfer Function: The ratio of the Fourier transform of the output
phase noise of a system divided by the Fourier transform of the input phase
noise for that system. This is a transfer function. It has a magnitude and a
phase. It's a mapping between an input and an output.
Both of these terms have been widely used in communications analysis for a long
time. For example the Bell Labs "Blue Book":
Members of the Bell Labs Technical Staff, Transmission Systems for
Communications, Fifth Edition, pg. 723-40, copyright Bell Telephone
Laboratories, Inc. 1982.
Thanks for your understanding and your cooperation.
Mike Steinberger
On 09/22/2011 12:57 PM, Walter Katz wrote:
All,
There have been several suggestions to enhance AMI to support a Jitter Transfer
function for the Tx input and Rx CDR reference clock. The Jitter Transfer
Function is simply a table containing two columns; Frequency and Amplitude.
This table can either be a Table in the .ami file or a pointer to a file
containing the table.
So the following specific questions:
1. Do we want the .ami file to contain a Jitter Transfer Function for the
Tx stimulus and the Rx reference clock?
2. If yes.
a. Do we want to add this to the Jitter BIRD (BIRD123), or create a new
BIRD?
b. Do we this to be implement as a Table in the .ami file and/or a pointer
in the .ami file to a file?
Walter
Walter Katz
wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 720.333-1107
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