Mixer Stream - 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/Stream IO

Description

This block implements the stream-based Mixer targeted for AI Engines.

Parameters

Main
Input/Output Data Type:
  • Describes the type of individual data samples output of the DDS function. It should be cint16, cint32, or cfloat.
Input Frame Size (Number of Samples):
  • Specifies the number of samples in the input frame. The value must be in the range 8 to 1024 and the default value is 32.
Mixer Mode:
  • This specifies the mixer operation modes. Two modes are supported by Mixer function:
    Single Input Mode
    This is a DDS plus Mixer for a single data input port. Each data input sample is complex multiplied with the corresponding DDS sample to create a modulated signal that is written to the output window. This is the default Mixer mode.
    Dual Input Mode
    This is a special configuration for symmetrical carriers and two data input ports. Each data sample of the first input is complex multiplied with the corresponding DDS sample to create a modulated signal. Each data sample of the second data input is complex multiplied with the conjugate (which is equivalent to a signal rotating in the opposite direction) of the DDS sample to create a second modulated signal. These two modulated signals are added together and written to the output window.
Number of parallel input/output (SSR):
  • This parameter specifies the number of input (or output) ports and must be of the form 2^N, where N is a non-negative integer.
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.
Initial Phase Offset:
  • Specifies the initial phase offset. The default value is 0.
Advanced
Target Output Throughput (MSPS):
  • Specifies the output sampling rate of the Mixer function in Mega Samples per Second (MSPS). The value must be in the range 1 to 1000 and the default value is 200.