Requires: Digital Filter Design Toolkit

Right-click an FPGA target in the Project Explorer window and select Start IP Generator from the shortcut menu to display the Start IP Generator dialog box. Select Multirate Filter and click the OK button to display the Generate LabVIEW FPGA Code for Multirate Filter dialog box.
Note The Start IP Generator dialog box is available only if you install the LabVIEW FPGA Module and NI-RIO driver software on the host computer.

Use the Generate LabVIEW FPGA Code for Multirate Filter dialog box to generate LabVIEW FPGA code for fixed-point multirate filters. You can implement the resulting LabVIEW FPGA code on NI FPGA targets to perform fixed-point filtering.

This dialog box includes the following options:

  • FilesContains the following options:
    • Filter file to loadSpecifies the filter file from which you want to generate LabVIEW FPGA code. You can obtain the filter file by using the DFD Save to File VI.
      Note If you did not quantize the filter, LabVIEW quantizes it by using the default settings of the DFD FXP MRate Quantization VI.
    • Filter VI to generateSpecifies the full path to the filter VI that LabVIEW generates, including the filename.
  • Fixed-Point ModelingSpecifies the settings for modeling the filter. If you already modeled the filter, LabVIEW loads the modeling settings from the filter file. You can choose from the following options:
    • Input Data TypeSpecifies the input word length and input integer word length of the filter.
      • Word lengthSpecifies the word length, in number of bits, that LabVIEW uses to represent the input signal. The valid range is [1, 32].
      • Integer word lengthSpecifies the integer word length, in number of bits, that LabVIEW uses to represent the input signal. The valid range is [2048, 2047].
    • Output Data TypeSpecifies the output word length and output integer word length of the filter.
      • Adapt to sourceSpecifies whether LabVIEW decides the word length and integer word length of the output signal.
      • Word lengthSpecifies the word length, in number of bits, that LabVIEW uses to represent the output signal. The valid range is [1, 32].
      • Integer word lengthSpecifies the integer word length, in number of bits, that LabVIEW uses to represent the output signal. The valid range is [2048, 2047].
    • Rounding modeSpecifies the rounding mode that LabVIEW uses in the output quantizer.
  • Magnitude ResponsesDisplays the plot of the magnitude responses of the reference floating-point filter and the fixed-point filter.
  • ImplementationSpecifies the settings for implementing the filter. You can choose from the following options:
    • Number of channelsSpecifies the number of channels that you want the generated code to process for each data path. The valid range is [1, 255]. The default is 1. If the multirate filter is a cascaded integrator comb (CIC) filter, the valid range is [1, 32].
      Note The generated multirate filter block does not have front panel indicators or controls. The generated multirate filter block has two FIFOs, filtername_DataIn and filtername_DataOut, to communicate with the data source and the destination of the filtered signal. For a multi-channel multirate filter, data from multiple channels is interleaved into a single input. You are responsible for controlling the data sequence into/out of the filter block.
    • ThroughputSpecifies the minimum number of cycles between two successive values of valid input data.
    • Throughput configurationDisplays the Throughput Configuration dialog box.
  • FeedbackDisplays information about the filter type and LabVIEW FPGA code generation, such as the maximum input sampling frequency per channel.
  • More OptionsConfigures additional settings for generating the LabVIEW FPGA code. Click this button to display the More Options for Multirate FIR Filter dialog box.