AVR 16-bit Fixed Point FFT Routines
Neil Klingensmith
2011-09-15


To perform forward FFT:

fix_fft(realpart, imagpart, LOG2NFFT, 0) ;

Where:
	realpart = real part of the time domain signal
	imagpart = imaginary part of the time domain signal
	LOG2NFFT = log base 2 of length(realpart). e.g. if length(realpart) = 16, LOG2NFFT = 4.
	0        => forward FFT

To perform inverse FFT:

fix_fft(realpart, imagpart, LOG2NFFT, 1) ;

Where:
	realpart = real part of the frequency domain signal
	imagpart = imaginary part of the frequency domain signal
	LOG2NFFT = log base 2 of length(realpart). e.g. if length(realpart) = 16, LOG2NFFT = 4.
	1        => inverse FFT







