PAM Eye Skews

The Eye mode PAM Eye Skews measurement measures the skew (seconds or UI) of each of the three eyes of a PAM4 eye diagram relative to the average center time of all eyes. On NRZ signals, this measurement measures the time at the center of the single eye.

Settings That Affect This Measurement

Setting	Description
PAM-N Analysis Setup Dialog Box Settings
Receiver Sample Timing	Configures the timing for sampling the signal data for all PAM measurements in Eye/Mask mode.
Eye Center Location	Selects the basis for determining the location of an eye's center on the waveform: at maximum eye width or maximum eye height.
Eye Level Width	Defines the timespan (in percentage of symbol width) over which an eye's amplitude level is measured.
Time Units	Sets the time units for measurement: seconds or unit intervals.

• Overall PAM4 measurement algorithm for Eye mode

The skew of each eye is calculated by:

1. For each eye, determine the time at the eye's center, which is the time at the measured eye height. Eye height is affected by the Eye Opening Probability setting.
2. Calculate the average time of all eyes.
3. Skew for each eye is the time of the eye relative to the average time calculated in step 2.
4. Display the measurements in the units specified in the Time Units setting.

To measure

1. Select Eye/Mask Mode.
2. Click Auto Scale in the menu toolbar.
3. Click the toolbar's PAM tab.
4. On the toolbar, locate and click the Eye Skews button.

SCPI Command

:MEASure:EYE:PAM:ESKew