1.4.2.29 DSP_TransformFFT16_setup Function
Creates FFT coefficients for use in the FFT16 function.
Description
void DSP_TransformFFT16_setup(int16c *twiddles, int log2N);
Calculates the N twiddle factors required to operate the FFT16 function. These factors are done in serial fashion, and require considerable processing power. Ideally this function would be run only once prior to an ongoing FFT, and the results held in a buffer.
Preconditions
twiddles must be N in length N is calculated (2^log2N)
Parameters
twiddles pointer to a complex array of factors (int16c)
log2N binary exponent of number of data points (int)
Returns
None.
Remarks
This function is of considerable length and executed in C.
It is recommended it only be called once for any given FFT length in time sensitive applications.
Example
see DSP_TransformFFT16 for example.
C
void DSP_TransformFFT16_setup (int16c * twiddles , int log2N );