Vector DDFS - 2020.2 English

Vivado Design Suite Reference Guide: Model-Based DSP Design Using System Generator (UG958)

Document ID
Release Date
2020.2 English

The Vector DDFS block generates Real and Imaginary vector output signals of desired frequency.


The input port I is used for providing the desired output frequency value as a vector type.

The input port I value should be equal to:

(desired output Frequency * Sampling time *2^(Frequency Resolution))

The VI input port and VO output are used for synchronization purposes with the other blocks in the design. The VO is just a delayed version of VI based on the block latency. The DITH input port is used to turn on/off the phase noise dithering feature. The CONJ input port is set to '1' to conjugate the complex exponential output. The output ports, O_RE and O_IM, generate Real and Imaginary components of the desired vector output frequency signal.

Data Type Support

  • The input port I should be a signed fixed-point data type.
  • The input port VI, DITH, and CONJ should be Boolean data types.

Block Parameters

Super Sample Rate (SSR)

This configurable GUI parameter is primarily used to control the processing of multiple data samples on every sample period. This block enables 1-D vector support for the primary block operation.

Frequency Resolution (bits)

Defines the smallest incremental step in frequency that the block can output. This should be an integer value.

Sin/Cos Table Depth

Defines the depth of the Sin/Cos Table and should be an integer value.

Sin/Cos Table Width

Defines the width of the Sin/Cos Table and should be an integer value.