Teledyne LeCroy QPHY-DDR2 - Manual (Page 24)

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QPHY-DDR2-OM-E Rev A
Skew
This field shows the measured skew between the probe in the specified channel and the reference channel. This
can be entered manually or as the result of an automatic calibration. In the case of automatic calibration, it can be
the result of a portion of the full calibration or it can be the result of a standalone deskew calibration. Even after
the deskew has been performed automatically, the deskew correction can be adjusted manually.
Clear
All probe calibrations can be cleared by pressing this button corresponding to a specific probe.
Calibration Source
This field specifies the signal source used for DC calibrations. When using the PCF200 fixture, specify AUX OUT
as the calibration source (even if the PCF200 is connected to Fast Edge output). This signal is not used for
deskew.
Calibration Skew Reference
These values specify the channel or external input where the skew reference is supplied. The skew reference is
the absolute time reference to which all deskew measurements are made. When the PCF200 fixture is used,
select the EXT input.
Recall Calibration
Whenever a probe calibration is applied, the oscilloscope saves the information in a file on the disk. If the
oscilloscope must be rebooted for any reason, the probe calibration information is always cleared, but can be
manually recalled by pressing this button.
Advanced Mode Checkbox
When the Advanced Mode checkbox is unchecked, you have access to the basic probe calibration menu. The
basic probe calibration menu shows you only what is absolutely needed to perform a simple calibration of the
probes. In other words, it shows you the calibration information and provides the capability to calibrate the probe
with a single button press, clear the calibration information, and manually reload the calibration information
following an oscilloscope reboot. When the advanced mode button is checked, you have access to the advanced
mode probe calibration menu.
This checkbox must be checked for deskew calibration using PCF200.
Advanced Mode Probe Calibration Menu
The advanced mode is entered by checking the advanced mode box in the basic probe calibration menu.
Figure 18. Advanced Mode Probe Calibration menu