For dsPIC® Digital Signal Controllers (DSCs), how can the FFT be used with data block lengths that are not a power of two?

The fast Fourier transform (FFT) size must be a power of two. In the case where the number of input samples is not a power of two, extra elements can be added to the input data array. The newly added elements are set to zero in a process known as zero padding. The DSP library supplied with the MPLAB® XC16 C Compiler includes a function for this called VectorZeroPad.

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