Teledyne LeCroy QPHY-DDR4 - Manual (Page 41)

QPHY-DDR4 Software Option
In the Measure section:
• tBurst W (P2) displays the number of W bursts detected in the acquisition.
• ClockFreq (P8) is the measured clock frequency from the acquired waveform
• VIHL_AC (P11) calculates the minimum eye opening for each UI. The measured value is reported
as VIHL_AC min.
Read Bursts (Outputs) - DQ and DQS Eyes
This is an informational only test that creates an eye diagram for DQ and DQS of all of the R bursts
detected in the acquisition. DQS is the timing reference for both eye diagrams and the reference point is
shown on the second division.
After the completion of the Read Bursts (Outputs) – DQ and DQS Eyes the oscilloscope is in the following
configuration:
Figure 27 - Oscilloscope Configuration after Read Bursts (Outputs) Test
Shown on this screen:
• F6 is the DQS eye diagram of the R bursts from the acquired signal. DQS is used as the timing
reference for this test which causes the eye to come to a “pin point” on the second division. This
math function is assigned an alias based on the assigned DQS signal name. The number of bits
contained in the eye diagram is displayed in the bottom row of the F6 descriptor box. In this case
there are 7,000 DQS bits in the eye.
• F7 is the DQ eye diagram of the write bursts from the acquired signal. This math function is assigned
an alias based on the assigned DQ signal name. The number of bits contained in the eye diagram
is displayed in the bottom row of the F7 descriptor box. In this case there are 7,000 DQ bits in the
eye.
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