Teledyne LeCroy QPHY-DDR4 - Manual (Page 60)

interpolation algorithm has determined where the device is no longer driving. This is the signal
which is measured in this test.
Figure 50 – tHZ/tLZ Results
In the Measure section:
• tHZ (P1) is measuring the time from CK at Vref to the time DQ quits driving. This time is indicated by
the trace label which is found through interpolation. Essentially the time between the two trace
labels is measured. The maximum value is the measured value for tHZ(DQ) max. This test is
considered informational only since the limit is undefined.
• tDQDQS (P2) is measuring the skew between DQ and DQS. Since this measurement is performed
once per burst, this shows how many R bursts were in the acquired waveform.
• t@tHZmax (P3) displays the location of where the maximum value of tHZ occurred. This is used to
position the zoom traces at the location of the “worst case results”.
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