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Keysight Technologies
Serial Data Equalization Software for
Infiniium Series Oscilloscopes
Data Sheet
02 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
Significantly reduce receiver errors by opening even
tightly shut eyes through equalization emulation
Keysight Technologies, Inc. serial data equalization software for Infiniium Series
oscilloscopes provides fast and accurate equalization simulating decision feedback
equalization (DFE), feed-forward equalization (FFE), and continuous time linear
equalization (CTLE) modeling in real time. Serial data equalization software allows users
to input their own self-designated tap values or will find the optimal tap values for the
designer for FFE and DFE. CTLE allows DC gain and up to three pole modeling.
Used in conjunction with the Infiniium Series unique Infiniium data accelerator (IDA) chip,
serial data equalization software provides fast update rates and rapid analysis of
real-time eyes that have been partially or fully closed by the serial data link. The serial
data equalization software package includes a wizard that provides an easy-to-follow
step-by-step process to set up and emulate full equalization.
Figure 1: Complete link
03 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
Equalization FAQ
1. Why do I need equalization?
As data rates go up, the signal deteriorates from the transmitter to the receiver
due to ISI, noise, etc. The more loss that occurs, the more difficult it is for a
receiver comparator to distinguish a "1" from a "0". A high data rate coupled with a
lossy channel will cause an open eye at a transmitter to be closed at the receiver.
Receivers need to be able to evaluate 1's and 0's; As eyes get more and more
closed, the receiver has a more difficult time interpreting the correct value as a
1 or a 0. This difficulty ultimately leads to significant data corruption and errors.
Equalization uses advanced filtering techniques to correct the voltage level of the
current bit. By removing much of the intersymbol interference through filtering,
equalization can improve closed eyes into open eyes and significantly reduce the
data corruption. The equalization software provides insight into designers'
equalizer designs and key data into the viability of the channel link after
equalization.
2. What is the difference between decision feedback equalization (DFE) and
feed-forward equalization (FFE)?
FFE typically looks only at the bits preceding the current bit to open the eye while
DFE dynamically will change based on the current bit in addition to any previous
bits. FFE uses the same filter for each receiver and every bit. DFE is adaptive and
can vary by device. DFE can be used in addition to FFE; however FFE cannot be
used in addition to DFE.
3. Why is it important to use an oscilloscope with low noise when using equalization
software?
If an oscilloscope has the lowest noise, the equalization technique will open the
eye wider. Keep in mind that equalization will amplify any noise not caused by ISI,
which by definition includes oscilloscope noise. Infiniium oscilloscopes have the
industry's lowest noise floor, so there is much less noise to be amplified. This
results in greater equalization accuracy.
4. Why does the equalization software require serial data analysis software?
Equalization requires the oscilloscope to know where the clock transitions. Clock
data recovery allows the scope to know where the transition occurs, making
equalization possible. Full clock data recovery can only be found in the serial data
analysis software package.
04 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
Easy Equalization Setup
The serial data equalization software extends the ease-of-use advantages of Keysight's
Infiniium oscilloscopes to complete analysis of the receiver. The equalization wizard
walks you quickly through the steps required to setup and perform equalization. Intuitive
displays and clear labeling of information make it easy to perform complex equalization
emulation. The serial data equalization wizard walks you through seven different equal-
ization scenarios.
Equalization wizard options
1. FFE or CTLE are emulated, but the real time eye is not displayed. You will see only
the waveform. This option lets you use the equalized waveform to perform further
analysis on it such as jitter decompensation.
2. No equalization applied. Option 2 is to see the eye with no equalization applied.
The option works great for comparing the impact of different equalization
techniques.
3. FFE or CTLE are applied only to recover the clock, but the referenced eye is
unequalized. As real time eyes get closer to being fully closed, it can be difficult
for the software to recover a clock because it can be difficult to distinguish
between a 1 and 0 and provide the correct data rate. This option makes it possible
to easily recover the clock, even on closed eyes.
4. FFE or CTLE emulation.
5. Standard DFE emulation. One caveat for this option is that if your real time eye is
closed, the DFE will not work correctly. You will need to use the next option to use
FFE or CTLE to open the eye a little bit and then DFE.
6. Standard DFE emulation for a closed eye. Note that FFE or CTLE is used to recover
the clock, but is not displayed in the real time eye.
7. FFE is applied and then DFE is applied to the real time eye. Both are displayed in
the resulting real time eye.
Figure 2: Equalization options from the wizard
05 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
CTLE, FFE and DFE
Emulation
The serial data equalization software will
provide full emulation of decision
feedback, feed-forward or continuous time
linear equalization. The software provides
the flexibility to compare real time eyes
of a non-equalized waveform versus an
equalized waveform or to compare a DFE
waveform versus an FFE or CTLE
waveform.
In addition to allowing you to compare
DFE versus FFE or CTLE equalization
techniques, the serial data equalization
software allows you to quickly
compare different tap values. Tap values
are dimensionless correction factors
applied to the bit voltage levels in serial
data patterns during equalization. Tap
values can be viewed as the ratio of the Figure 3. Equalization menu in the equalization wizard
voltage the receiver should have seen
versus what the receiver actually did see.
Accurate tap values are essential for
modeling an ideal real time eye at the
receiver. Serial data equalization software
will save you time by modeling up to forty
tap values for you. In addition to this, you
can use the serial data equalization
software package to find what
combination of tap values will maximize
eye height. SDE software provides pre Figure 4. Automatically find the tap values
cursor tap functionality for FFE emulation.
Serial data equalization provides multiple
inputs including an "Eye Width" option
that optimizes the tap values based on
whether the designer wants a wider or
higher eye. Unlike some equalization
emulation packages, serial data
equalization will work on any pattern and
the software doesn't need to know the
pattern the designer is using.
Figure 5. Equalization allows you to choose between FFE, CTLE, and DFE
06 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
Continuous Time Linear Equalization (CTLE)
CTLE
Many of today's standards require CTLE as part of compliance testing. The SDE software
makes verifying emulation easy. Simply enter your DC gain value, zero frequency, and
pole1 and pole2 frequency values to verify your design.
Serial data equalization also supports USB 3.5's specific CTLE.
Figure 6. Serial data equalization supports both 2- and 3-pole CTLE
07 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
Flexible Clock Recovery
You can choose constant-frequency, first-order phase-locked
loop (PLL), second-order PLL clock recovery, explicit clock,
explicit first order PLL, explicit second order PLL or FibreChannel
clock recovery methods. You can adjust the center frequency and
bandwidth, and in the case of second-order PLL, the damping
factor.
New to the equalization software is the equalized first and second
order PLL, which allows you to recover the clock on a closed
eye. This is accomplished by first applying FFE or CTLE to the
waveform and then recovering the clock, making clock recovery
possible even on closed eyes.
Oscilloscope compatibility
The N5461A Infiniium serial data equalization software is
compatible with Infiniium 9000, 90000A, 90000 X- and 90000 Figure 7. Clock recovery set up
Q-Series oscilloscopes with operating software revision 1.40 or
higher (Windows XP Pro). For oscilloscopes with earlier software
revisions, free upgrade software is available at:
http://www.keysight.com/find/infiniium_sw_download.
The software is also now available as part of Infiniium Offline,
meaning you can do all your equalization emulation at your PC
and not be tied to the oscilloscope.
Ordering information
To purchase the N5461A Infiniium serial data equalization
software for your new or existing 9000, 90000A, 90000 X- or
90000 Q-Series oscilloscope, order the following:
For Infiniium Series oscilloscopes
License type Infiniium Z-Series Infiniium S-Series Infiniium 90000A, X-, Infiniium 9000 Series
or Q-Series
Fixed Factory-installed N5461B-1FP N5461B-1FP Option 012 Option 012
User-installed N5461A-1NL N5461B-1NL
Floating Transportable N5461A-1TP N5461A-1TP N5461A-1TP N5461A-1TP
Server-based N5435A-025 N5435A-025 N5435A-025 N5435A-025
08 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
Related literature
Publication title Publication type Publication number
Keysight E2688A, N5384A High-Speed Serial Data Analysis and Clock Recovery Software Data sheet 5989-0108EN
for Infiniium Oscilloscopes
Infiniium 9000 Series Oscilloscopes Data sheet 5990-3746EN
Infiniium 90000 Series Oscilloscopes Data sheet 5989-7819EN
Infiniium 90000 X-Series Oscilloscopes Data sheet 5990-5271EN
Infiniium S-Series Oscilloscopes Data sheet 5991-3904EN
Infiniium Z-Series Oscilloscopes Data sheet 5991-3868EN
Keysight Oscilloscopes
Multiple form factors from 20 MHz to >90 GHz | Industry leading specs | Powerful applications
09 | Keysight | Serial Data Equalization Software for Infiniium Series Oscilloscopes - Data Sheet
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