DSPF_sp_ifftSPXSP_c2r
[Fast Fourier Transform]

Collaboration diagram for DSPF_sp_ifftSPXSP_c2r:


Detailed Description

void DSPF_sp_ifftSPxSP_c2r (int N, float *ptr_x, float *ptr_w, float *ptr_y, unsigned char *brev, int n_min, int offset, int n_max)


Function Documentation

void DSPF_sp_ifftSPxSP_c2r ( int  N,
float *  ptr_x,
float *  ptr_w,
float *  ptr_y,
unsigned char *  brev,
int  n_min,
int  offset,
int  n_max 
)

The benchmark performs a mixed radix inverse fft.

Parameters:
N length of FFT in complex samples
ptr_x pointer to complex data input
ptr_w pointer to complex twiddle factor
ptr_y pointer to real output data
brev pointer to bit reverse table containing 64 entries
n_min should be 4 if N can be represented as Power of 4 else, n_min should be 2
offset index in complex samples of sub-fft from start of main fft
n_max size of main fft in complex samples
Algorithm:
DSPF_sp_ifftSPxSP_c2r_cn.c is the natural C equivalent of the optimized linear assembly code without restrictions. Note that the linear assembly code is optimized and restrictions may apply.
Assumptions:
N needs to be power of 2
8 <= N <= 131072
Arrays pointed by ptr_x, ptr_w, and ptr_y should not overlap
Arrays pointed by ptr_x, ptr_w, and ptr_y should align on the double words boundary
Implementation Notes:
Interruptibility: The code is interrupt-tolerant but not interruptible.
Endian Support: The code supports both big and little endian modes.


Copyright 2014, Texas Instruments Incorporated