Teledyne LeCroy QPHY-HDMI - Manual (Page 18)

QPHY-HDMI Testing
Test Preparation
Before beginning any test or data acquisition, the oscilloscope should be warmed for at least 20
minutes.
Calibration is automatic under software control and no manual calibration is required. The
calibration will be run again if the temperature of the oscilloscope changes by more than a few
degrees.
Required Test Modes
The QPHY-HDMI script requires that you place the DUT (Device Under Test) in the required test
modes. The script will prompt you to do so before each specific test, but it is recommended that
you ensures the DUT is capable of being placed in the required test modes before beginning
testing.
Physical Setup
The Teledyne LeCroy direct measurement solution uses SMA cables to connect two differential
signals at one time to the oscilloscope channels through the TF-HDMI-3.3V SIG input. SMA
cables are also used to terminate the unused signal onto specific TERM inputs.
See the description of each test configuration for specific set up information.
Deskew
HDMI signals are properly probed using two separate channels on the oscilloscope connected
to the appropriate SMA jacks on the test fixture. The highest measurement accuracy is achieved
when the timing skew between the two channels is calibrated.
The configurations will guide you through an initial deskew procedure. See the end of this
manual for two approaches to deskew. For optimal results, we recommend that you always first
deskew channels 2 and 3, then channels 1 and 2, followed by channels 3 and 4.
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