# :MEASure:JITTer:JITTer:DDPWs?

Jitter DDPWS Commands

- :MEASure:JITTer:JITTer:DDPWs?
- :MEASure:JITTer:JITTer:DDPWs:STATus?
- :MEASure:JITTer:JITTer:DDPWs:STATus:DETails?
- :MEASure:JITTer:JITTer:DDPWs:STATus:REASon?

## Query Syntax

    :MEASure:JITTerN:JITTer:DDPWs?

Where N identifies one of four possible jitter/noise analyses {1:4}. For example, `JITTer4`.

## Description

The DDPWS (Data Dependent Pulse Width Shrinkage) measurement implements the equation:

> T - min(all pulse widths)

Where T is the nominal bit width determined by the user-specified clock recovery algorithm.

For constant frequency clock/data recovery (CDR), this is the reciprocal of the best fit data rate through the acquisition.

For PLL clock/data recovery (CDR), this is the average of the PLL data rate throughout the acquisition.

The pulse widths are measured at the user specified thresholds. Because it is the min of all pulse widths, one measurement is provided per acquisition. The markers are placed on the minimum pulse width.

For the DDPWS measurement to appear, these selections must be made in the Jitter measurement setup dialog box:

1. TIE (Phase) must be selected as the Jitter Measurement.
2. Periodic must be selected for Pattern Sequence (in Advanced settings tab).
3. Both Edges must be selected for Show Results Based on these Edges.