PAM Level Skews

The Eye mode PAM Level Skews measurement measures the skew (seconds or UI) of each level (0, 1, 2, 3) of a PAM4 eye diagram relative to the average center time of all levels. On NRZ signals, this measurement will measure the level one and zero skew relative to each other.

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 of Level	Specifies the method used to locate the time at which to measure an eye's level.
Time Units	Sets the time units for measurement: seconds or unit intervals.

• Overall PAM4 measurement algorithm for Eye mode

The skew of each level is calculated by:

1. For each level, determine the time at which the level's thickness is at a minimum value. The minimum value is determined by minimum RMS or peak-to-peak values (Level Time Method setting).
2. Calculate the average time for all levels measured in step 1.
3. Skew for each level is the time of the level calculated in step 1 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 Level Skews button.

SCPI Command

:MEASure:EYE:PAM:SKEW