Unit Interval

The Unit Interval measurement searches your waveform for the narrowest data pulse and uses it as the ideal unit interval for computing the statistics.

There are two modes that can be used to find the data:

  • In Automatic mode, the data rate is found by searching your waveform for the narrowest data pulse. When the Automatic mode has trouble finding the data rate due to excessive high-frequency jitter on the waveform, the Semi Automatic mode can be used.
  • In the Semi Automatic mode, Infiniium starts by searching around the Symbol Rate that you specify then automatically finds the data rate.

When measuring over the waveform, the Unit Interval measurement is made on all the cycles of the waveform including any cycles that are not in the waveform window. When measuring in a region, the Unit Interval measurement is made on all the cycles inside the region only.

Configurable Measurement Parameters

This measurement is affected by the following settings (choose Measure > Thresholds...):

To measure

  1. Click the toolbar's Data tab.
  2. Click the Unit Interval button.
  3. Select the signal on which to make the measurement.
  4. Select the Region in which to make the measurement:
    • Displayed Waveform — is what you see in the waveform window (which can be a zoomed-in view of the complete waveform).
    • Entire Waveform — specifies the complete waveform.
    • Region N — If regions are enabled for the selected signal, you can select one of those regions.
  5. Select the Data Width Calculation as either Automatic or Semi Automatic.
  6. If the Data Width Calculation is Semi Automatic, specify the Nominal Data Rate for the selected signal.
  7. Click Apply.

SCPI Command

:MEASure:DATA:UINTerval