LeCroy DDA 7 Zi series, Operator'S Manual

Page: 393 / 544

Operator's Manual
WP700Zi-OM-E-RevA
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deterministic jitter separation, and direct measurement of periodic jitter, DDj, and DCD. The SDA also provides
the capability to directly measure failed bits and to indicate their locations in the bit stream.
Note:
SDA
- name of the instrument: Serial Data Analyzer
SDM - Serial Data Mask testing package, available on WaveMaster, WaveRunner Series, and WavePro Series
oscilloscopes. Not available on the SDA.
SDA Capabilities
In addition to all the standard WaveMaster scope measurement functions, the SDA provides two other types of
measurements: jitter and eye pattern. It also includes bit error rate analysis to the SDA. These measurements are
available together in the summary screen, as well as in individual modes.
Measurements on the SDA are performed on long, continuous acquisitions of the signals under test. All jitter
measurements and all displays are based on times of successive edges of the signal only; nothing is relative to
the trigger. As a result, they are not affected by trigger jitter. Acquisitions should be long enough to include at
least several thousand UI of the signal under test: 30,000 UI or more is optimal. To see low frequency jitter, it may
be desirable to acquire longer records. Acquisitions can be up to the full available memory depth of the instrument
(up to 258M samples with option SDA Zi-L-128), which may take considerable time to process.
Serial Data Analysis, which includes mask testing and jitter parameters (Rj, Dj, Tj, DDJ, Pj, DCD), is standard in
the SDA. It is also available with option ASDA-J, which adds a major upgrade in capability over the standard SDA
instrument. The different measurements available with each configuration are shown in
Table 1 .
SDM Capabilities
The capabilities of option SDM are standard in the SDA, so it is not available for purchase for the SDA. This
option is only available for the WaveMaster, WaveRunner 6000 Series, and WavePro 7000 Series of
oscilloscopes. SDM adds eye pattern testing to these oscilloscopes.
The option also adds other key components to the basic scope, including JTA2 with its TIE@lvl parameter.
TIE@lvl is a JTA2 measurement that measures the time interval error of the crossing points of the signal under
test and, with option SDM, also includes a golden PLL clock recovery module that is used for forming the eye
pattern without an external trigger. Standard masks are included with option SDM as indicated in
Table 2 . Note
that not all data rates can be tested with all oscilloscopes. The analog bandwidth limits the upper data rate that
can be tested.
Advanced Capabilities
In its standard form, the SDA includes eye pattern testing with mask hit indication; Jitter testing, including jitter
bathtub computation and separation of jitter into its random and deterministic components; as well as the
breakdown of deterministic jitter into periodic, data dependent, and duty cycle distortion.
Standard advanced features include:
x
Mask violation location This is the ability to list and view the individual bits that violate the selected mask.
(Mask violation location takes much more time than jitter testing; acquisition size should be just a few
thousand UI.)
x
Filtered jitter Processes the time interval error trend vs. time with a user-selectable band-pass filter. This
feature provides peak-to-peak and rms measurements of the jitter on the filtered waveform.
x
ISI plot Generates an eye diagram including only those affects from data dependent sources. The user can
select from 3 to 10 bit patterns for this test and can view the contribution from any individual pattern. The
ISI plot is an alternate method for measuring data dependent jitter when the signal under test does not
contain a repeating bit pattern.
x
Bit error test with error map Measures the number of bit errors and error rate on the acquired waveform by
converting the wave shape to a bit stream and comparing the result to a user-definable reference pattern.
The data can be further divided into frames that can be arranged in a 3-dimensional map with frame
number on the Y-axis, bit number on the X-axis, and failed bits shown in a light color.