Getting Started
SDAX Descriptor and Status Messages
When SDAX is enabled, the SDAX descriptor box is added to the display next to the Timebase and Trigger
descriptors. Under normal operation, it shows the Serial Standard or custom signal type and data rate tested.
Touching the descriptor will re-open the SDA Expert dialogs, if they are closed.
However, if there is an application state that could possibly lead to erroneous measurements, the descriptor issues a
status message:
Click on the descriptor box to go to the setup dialog where the setting in question can be corrected. In some cases,
there will be a red "LED" indicator next to the problematic setting.
Following is a list of status messages that may appear in the SDAX descriptor.
Message Occurs when...
Emulate / Deembed setup needs attention Files (e.g., S-parameters) or settings required to de-embed / emulate a fixture or
channel have not been specified or are missing from the path; the de-embedding
setup has not been Applied in order to build the circuit model.
DFE training failed There is too low sample rate or too few UIs/pattern repetitions for the DFE to train;
the wrong pattern is specified.
Check Jitter status! There is no signal found on the specified input; a jitter analysis setting needs cor-
rection; there is a pattern mis-match.
Low statistics Too few UIs or pattern repetitions in acquisition for valid measurements.
Pattern mis-match! The signal pattern does not match the pattern specified for the measurements;
there is no recognizable signal on the input. Change the pattern from the DUT to
the pattern shown on the measurement dialog. If the pattern is still not recognized,
on the Test Pattern subdialog, choose a Built-in pattern or upload a pattern file.
Differential inputs required The measurement requires a differential signal, but the input selection is single-
ended. On the Signal dialog, make the selections required for a differential signal.
Be sure there is a differential signal on the designated channel(s).
Pattern inverted! The input signal pattern is the inverse of the expected pattern (perhaps due to inad-
vertently reversing the inputs). On the Test Pattern subdialog of the Signal dialog,
check Invert Pattern.
Pulse reference for TxEQ required An unequalized reference pulse must be saved prior to making Tx EQ meas-
urements. Go to the Tx EQ dialog and follow the procedure for Reference Pulse
Measurement.
No lanes enabled At least one Lane must be enabled (shown) for any measurements or graphs to be
displayed. On the SDAX dialog, choose a Lane, then check the Enable box next to it.
Accumulation complete The number of UIs/pattern repetitions set on the Accumulate dialog has been
reached. Additional acquisitions will not be computed into SDAX measurements.
Noise reference required The selected noise measurements require a saved reference pulse (to be used for
noise removal). Note: This is primarily used for PCIe 6.0 Compliance pattern meas-
urements.
Noise reference not enabled The noise reference pulse has not been applied to the model. Note: This is primar-
ily used for PCIe 6.0 Compliance pattern measurements.
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