Teledyne LeCroy QPHY-DDR4 - Manual (Page 49)

QPHY-DDR4 Software Option
Shown on this screen:
• Z2 is a zoom of F2, the acquired DQS signal after any probe deskew has been applied. The zoom is
positioned at the location of the “worst case” Overshoot Peak Amplitude measurement indicated
by t@PeakMax. A trace label is applied on this trace according to the signal name assigned to
DQS. This signal is not measured in this test and is only provided as a visual reference.
• Z3 is a zoom of F3, the acquired DQ signal after any probe deskew has been applied. The zoom is
position at the location of the “worst case” Overshoot Peak Amplitude measurement indicated by
t@PeakMax. A trace label is applied on this trace on the pulse with the worst overshoot peak
amplitude according to the signal name assigned to DQ. This is the signal which is measured in
this test.
Figure 36 – Overshoot/Undershoot Results
In the Measure section:
• OvershootPeak (P1) is measuring the overshoot peak amplitude above VDDQ for of each DQ
pulse. The VDDQ level is indicated by alternating dashed cursor and the peak amplitude level is
indicator by the other cursor. The peak amplitude is measured only 1 UI after a transition. The
maximum value is the measured value for DQ Overshoot peak amplitude Max. This test is
considered passing if the measured value is less than 400 mV.
• t@PeakMax (P3) displays the location of where the maximum value of OvershootPeak occurred.
This is used to position the zoom traces at the location of the “worst case results”.
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