12-Edge Output Jitter Jnu Result

Meas. mode:
Jitter
Waveform type:
PAM4
Output Jitter Table

The Jitter Mode 12-edge Output Jitter Jnu measurements (J1U, J2U, J3U, J4U, or J5U) are based on IEEE 802.3bs standard for Output Jitter measurements. All of the output jitter Jnu measurements are made on an RJ/PJ histogram at a specific output jitter probability. For example, J4u is defined as the time interval that includes all but 10–4 of the estimated probability distributions from the 0.005th to the 99.995th percentile. The measurement uses probability, because the measurement references a particular edge. The likelihood that these edges cause a bit error is low, because that must also account for the probability of that exact edge occuring.

At the selected probability, measurements are performed for each of the 12 edge transitions as well as for the combined effect of all edge transitions. The standard specifies that the measurement be performed using an PRBS13Q pattern. The measurement includes f/2 and uncorrelated data effects. On PAM4 signals that are derived from two NRZ signals, this measurement allows you to observe the effect of different uncorrelated jitter on each stream based on the transitioning bits.

  • To select the edges used used in the displayed Outer Jitter Histogram graph, use Show Graph of Edge Category field in the Jitter Measurements tab of the Jitter Mode Masurement Setup dialog.
  • To select the probability use in the measurement, use Select Jnu Type field in the Jitter Measurements tab of the Jitter Mode Masurement Setup dialog.

The following measurements are shown in the Output Jitter panel:

Jnu (All)
As called out in the standard, this measurement adds the probability distributions (histogram scaled by total hits) for each waveform edge type and makes the measurement on the combined distribution.
From Ln to Ln
These are the RJ/PJ histogram measurements for each of the 12 individual edge (level) transitions.

To run this measurement, click the 12-Edge Output Jitter button which is located on Jitter mode's Meas toolbar.

More Information

SCPI Command

:MEASure:JITTer:OJITter:JNU