Teledyne LeCroy QPHY-DDR4 - Manual (Page 66)

Figure 58 – tDIPW Results
In the Measure section:
• tDIPW (P1) is measuring the high time of DQS. The high time is determined by measuring the time
DQ crosses Vref on a rising edge (centered on the screen) at to the time DQ crosses the next
associated falling edge at Vref (indicated by the trace label). The minimum value is the measured
value for tDIPW min High and is reported in mUI. This test is considered passing if the minimum
value is greater than 0.58 UI.
• tDQDQS (P2) is measuring the skew between DQ and DQS. Since this measurement is performed
once per burst, this shows how many W bursts were in the acquired waveform.
• t@tDIPWmin (P4) displays the location of where the minimum value of tDIPW occurred. This is
used to position the zoom traces at the location of the “worst case results”.
tDSS/tDSH, DQS to CK Setup/Hold Time
The purpose of this test is to characterize the setup and hold time for a falling DQS edge to the rising CK
edge on W bursts. The minimum value is measured for both tDSS and tDSH.
Note: Only tDSS will be discussed below. The measurement methodology is the same for the tDSH
expect the hold time is measured rather than the setup time.
After the completion of the tDSS test the oscilloscope is in the following configuration:
Figure 59 - Oscilloscope Configuration after the tDSS test
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