LeCroy SDA, Operator'S Manual

Page: 348 / 397

348
SDA-OM-E Rev H
AltNcycle Control Summary
Control Values Description
Synch to pattern On/off Synchronizes the measurement to a
repeating data pattern (if present) in the
signal when this control is checked. The
timing is measured between the first
transition in the pattern and each
subsequent transition. For an N-bit pattern,
each transition is measured in succession
and measurements are accumulated by
shifting the measurement window by N bits
and repeating the measurement.
Ver. Output Mean, sdev, DDmean, DDsdev These are the vertical units of the
measurement. Mean gives the average
position of edges for each value of N relative
to a reference clock at the bit rate. Sdev
gives the standard deviation for each edge
for each value of N relative to the reference
clock. DDmean gives the mean value of
each edge relative to the first edge
normalized to a unit interval for each N.
DDsdev gives the standard deviation for
each edge relative to the first edge
normalized to a UI for each N.
Length (UI) The maximum N value This field displays the pattern length if Sync
to Pattern is selected. Otherwise, this is the
maximum N value displayed in the plot.
Tx dens. 0.0 to 1.0 Transition density of the data stream. This
control reads out the measured transition
density of the signal when the Find Pattern
button is pressed. This field is not used by
the N-cycle plot.
Seq. Type PRBS or Pattern Selects whether the repeating pattern is a
standard PRBS or a general pattern. This
control is only used when snyc to pattern is
selected.
PRBS 5 to 15 When PRBS is selected, sets the length.