DDS - 2022.2 English

Vitis Model Composer User Guide (UG1483)

Document ID
UG1483
Release Date
2023-01-13
Version
2022.2 English


Library

AI Engine/DSP/Window IO

Description

This block implements the Direct Digital Synthesizer (DDS) targeted for AI Engines.

Parameters

Main
Output data type
Describes the types of individual data samples output of the DDS function. The supported data types are cint16 and cfloat.
Output window size (Number of samples)
Specifies the number of samples in output window. The value must be in the range 8 to 1024 and the default value is 32.
Phase increment
Specifies the phase increment between samples. The value must be in the range 0 to 2^31 and the default value is 0. Input value 2^31 corresponds to Pi (i.e., 180).

Phase increment is calculated using the formula (Fo*(2^N)) / Fs

Where:
  • Fo = Output frequency
  • N = 32, which represents the accumulator width, and it is fixed
  • Fs = Sampling frequency
Sample time
Specifies the sample time for the block output port. The default value is -1.
Advanced
Target output throughput (MSPS)
Specifies the output sampling rate of the DDS function in Mega Samples per Second (MSPS). The value must be in the range 1 to 1000 and the default value is 200.