Waveform Top

Meas. mode:
Scope
Flex Apps:
FlexDCA
Waveform type:
NRZ
PAM4
Pulse
Oscilloscope Mode
Amplitude Toolbar

The Oscilloscope mode Waveform Top is the most prevalent value of the upper 40% of a pulse or eye diagram. This measurement may be compatible with PAM4 signals, depending on the PAM4 waveform. The measurement can be restricted to a measurement region. An annotation label is placed at the measurement result.

Depending on the waveform type, one of the following algorithms is employed:

  • Histogram Peak Algorithm. Used for square waveforms and low duty-cycle waveforms.
  • Maximum Algorithm. Used for waveforms that result in even histogram distributions, such as triangular waveforms. Using the histogram peak algorithm for waveforms that have even histogram distributions would result in an unstable identification of the Waveform Top.

PAM4 Compatibility. Because this measurement is based on waveform top and base levels and the passing of the waveform's edge through proximal, mesial, and distal thresholds, the measurement is not designed for PAM4 signals. However, the measurement may be able to be made on PAM4 signals if the waveform top and base definitions are manual set. This can be attempted using the Top-Base Definition tab of the Configure Measurements dialog.

This measurement may be compatible with PAM4 signals, depending on the PAM4 waveform. PAM measurement capability requires the Research and Developement or Manufacturing package license or the legacy PAM-N Analysis license.

The entire display or measurement region is used to calculate the result. Therefore, position a single cycle or an integer number of positive pulses in the display or region.

This measurement is available in oscilloscope mode only.

On the 86100D, this measurement is named V top.

Configurable Measurement Parameters

This measurement is affected by the following setting (click Measure > Configure Base Measurements):

To measure

  1. Select Oscilloscope Mode.
  2. Click the toolbar's Amplitude tab.
  3. Click the toolbar's More buttons to locate the Waveform Top button.
  4. Click the button.
  5. If measurement regions are enabled, the Select Measurement Region, Setting dialog is displayed. Select the area over which the measurement is to be performed: a Region or the Entire Display.

SCPI Command

:MEASure:OSCilloscope:VTOP