Manual

QPHY-DDR4 Software Option
Shown on this screen:
• RjBUjSpect is the RjBUj Spectrum of the differential clock signal. The signal type on the signal input
section of SDA III is setup to measure a Clock and to use “Period” as the Jitter Parameter.
Figure 17 - tJIT(per)_total and tJIT(per)_dj Results
In the SDA Jitter section:
• Tj(1e-12) is the total jitter calculated using the spectral direct method in SDA III. The user can modify
the BER level using the Jitter BER Level variable (see the QPHY-DDR4 Variables section for
more information). This value is reported as tJIT(per)_total in ps for informational purposes. The
value is also reported in UI to be tested against the limit from the specification.
• Rj(spD) is the random jitter calculated using the spectral direct method in SDA III. This value is
reported for informational purposes.
• Dj(spD) is the deterministic jitter calculated using the spectral direct method in SDA III. This value is
reported as tJIT(per)_dj in ps for informational purposes. The value is also reported in UI to be
tested against the limit from the specification.
tJIT(cc)_total, tJIT(cc)_dj, Total and Deterministic Cycle to Cycle Period Jitter
tJIT(cc) is defined as the absolute difference in clock period between two consecutive clock cycles.
After the completion of the tJIT(cc)_total and tJIT(cc)_dj tests the oscilloscope is in the following
configuration:
924291 Rev A 33