User`s guide

Random Data with Bit Clock
This tool makes measurements relative to a bit-clock. Therefore modulation or PJ cannot be determined.
Similarly because the histogram is composed of many different data transitions, the DCD+ISI value is not
directly determined. The DJ, RJ and TJ values are determined from a TailFit on the histogram of Rising
and Falling data edges.
To use this tool, you will need:
(1) A data signal
(2) A synchronous bit clock
This measurement is similar to that made by a scope using the bit clock as a trigger and analyzing a
particular data crossing point histogram.(above example). This tool is able to give more information and
separate the histograms of rising data edges and falling data edges.
Measurements RDwBC Can Make
DCD + DDJ PJ DJ RJ TJ Views (Plots)
X X X Histogram Probability Bathtub
Summary
Signal Requirements (1)Data Pattern (2)Bit Clock
Benefits • Compare to a Scope crossing point histogram
• Measure relative to a bit-clock
Disadvantages • Needs bit-clock (clock jitter will affect measurements
on data)
• Frequency of operation may be limited by hardware
• No spectral information
• Limited DJ accumulation
© WAVECREST Corporation 2005 Section 4 - GigaView
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