FFT/IFFT ParaCore Parameters

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Parameters used when compiling the Dillon Engineering FFT/IFFT IP Core

PARAMETER TYPE DESCRIPTION n Integer Number of points in the DFT (n must be power of 2) forward Select Forward or inverse FFT (assignment options are forward, inverse, or both). inputs Integer Number of data input paths (must be a power of 2) outputs Integer Number of data output paths (must be a power of 2) scale List Used for fixed-point data to selectively scale the data by 1 bit after each rank is executed. Scaling removes errors created by the overflow caused by the complex addition performed in each butterfly structure. type nType The nType definition specifies the fixed or floating-point data used by the FFT (see also the notes below). width Integer Used to define the width of fixed-point data (if floating-point data is selected, than refer to the following table for additional floating-point parameters). mag_out Boolean Produce magnitude output instead of complex results (note that when mag_out is active, the output port width will be reduced by half). hanning Select Used to select the type of Hanning Window (options are to select a formula type).

 

The following table defines the nType parameter, which is used to define the number types to be implemented by ParaCore Architect:

PARAMETER TYPE DESCRIPTION type Select Select number type (options are int or float). width Integer For type == int, this parameter sets the integer width. For type == float, this parameter is automatically set to e_width + m_width + 1 (see below). e_width Integer When type == float, this parameter defines the width of the exponent (it should be set to 8 for single precision and 11 for double precision). m_width Integer When type == float, this parameter defines the width of the mantissa (it should be set to 23 for single precision and 52 for double precision).