Anritsu BERTWave Series, Руководство по эксплуатации, Страница: 61 / 466

1.5 Technical Terms
1-35
1
Outline
Levels p-p, Levels RMS, Level Skews
When measuring the histogram of each level with PAM4 waveform, the
peak value of its width is Levels p-p and the standard deviation is Levels
RMS.
If Sample Timing is Independent, Levels p-p, Levels and RMS are
measured at the following positions.
Level 3 The center of Upper Eye
Level 2 Halfway between the center of Upper Eye and the center
of Middle Eye.
Level 1 Halfway of the center of Middle Eye and the center of
Lower Eye
Level 0 The center of Lower Eye
Level Skews are differences between the positions measured at each level
and their averages.
When Sample Timing is Track to Middle Eye Timing , Levels p-p and
Levels RMS are measured at the center of Center Eye. And Level Skews
are 0.
Figure 1.5-19 PAM4 Levels p-p and Levels RMS
(When Sample Timing is Independent)
Level 2
Level 1
Level 3
Level 0
Levels RMS
Levels p-p
Average of four measured positions
Level Skews
Upper Eye
Center
Lower Eye
Center
Middle Eye
Center