81250 Datasheet, PDF (7/64 Pages) Keysight Technologies – Agilent ParBERT 81250 Parallel Bit Error Ratio Tester

Automatic data synchronization
The latency between DUT input
and output is often not exactly
known or not even deterministic.
Having to set ParBERT’s sample
point for analysis manually
would be tedious.
Therefore ParBERT 81250
analyzers provide three modes
to automatically synchronize
and align upon expected data
with BER below a user defined
threshold as a criteria (figure 5).
• Auto Bit Sync
Finds the proper bit position
in a data stream. For memory
based patterns a unique detect
word is required. Automated
phase alignment is optional.
• Fast Bit Sync
Possible for PRBS/PRWS only.
Especially useful for burst-mode
applications, e.g. optical
re-circulating loops.
• Auto Delay Align
Only the sample point timing
of the analyzers is adjusted.
The latency between input
and output must be within the
delay range of the analyzers
used.
For applications w/o expected
data with ParBERT running in
data acquisition mode, e.g. for
A/D test, proper sample point
adjustment can automatically be
achieved with the CDR / lane
mode (7 and 13Gb/s analyzer
modules only)
Figure 6. ParBERT standard mode sequence editor with PRBS/PRWS patterns and data
synchronization mode chosen
Interrupt-free change of
analyzer and generator delay
The analyzer sample timing can
be adjusted ±1 period while the
instrument keeps running w/o
interrupting the measurement
(see figure 7).
For the 13.5 Gb/s, 7 Gb/s and
3.35 Gb/s the delay of the genera-
tor modules can be adjusted ±1
period while running as well.
Figure 7. Analyzer delay can be changed without
stopping the system, CDR/lane can be enabled
ParBERT 812507Main Overview
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