Fixed-point 16-bit FFT

Data Structures
struct	nrf_dsp_cfft_i16_s
struct	nrf_dsp_rfft_i16_s

Typedefs
typedef struct nrf_dsp_cfft_i16_s	nrf_dsp_cfft_i16_t
typedef struct nrf_dsp_rfft_i16_s	nrf_dsp_rfft_i16_t
typedef void(*	nrf_dsp_cfft_radix_func_i16_t) (const nrf_dsp_cfft_i16_t *p_cfft, int16_t *p_input)
	Complex FFT 16-bit radix function type.

Functions
void	nrf_dsp_rfft_init_i16 (nrf_dsp_rfft_i16_t *p_rfft, uint16_t len, const int16_t *p_twiddle_rfft, const int16_t *p_twiddle_cfft, const uint16_t *p_bitrev_table, uint16_t bitrev_table_len)
	Initialize real FFT instance structure.
void	nrf_dsp_rfft_i16 (const nrf_dsp_rfft_i16_t *p_rfft, int16_t *p_input, int16_t *p_output)
	The fixed-point 16-bit real FFT function Real FFT algorithms take advantage of the symmetry properties of the FFT and have a speed advantage over complex algorithms of the same length. This function can compute results "in-place" of input buffer.
void	nrf_dsp_rfft_rdx_i16 (const nrf_dsp_rfft_i16_t *p_rfft, int16_t *p_input, int16_t *p_output, nrf_dsp_cfft_radix_func_i16_t radix_func)
	The fixed-point 16-bit real FFT function with custom radix function to use. Real FFT algorithms take advantage of the symmetry properties of the FFT and have a speed advantage over complex algorithms of the same length. This function can compute results "in-place" of input buffer.
void	nrf_dsp_cfft_init_i16 (nrf_dsp_cfft_i16_t *p_cfft, uint16_t len, const int16_t *p_twiddle_cfft, const uint16_t *p_bitrev_table, uint16_t bitrev_table_len)
	Initialize complex FFT instance structure.
void	nrf_dsp_cfft_i16 (const nrf_dsp_cfft_i16_t *p_cfft, int16_t *p_input, uint8_t bitreverse_flag)
	The fixed-point 16-bit complex FFT function.
void	nrf_dsp_cfft_rdx_i16 (const nrf_dsp_cfft_i16_t *p_cfft, int16_t *p_input, uint8_t bitreverse_flag, nrf_dsp_cfft_radix_func_i16_t radix_func)
	The fixed-point 16-bit complex FFT function with custom radix function to use.
void	nrf_dsp_cfft_radix4_i16 (const nrf_dsp_cfft_i16_t *p_cfft, int16_t *p_input)
	The fixed-point 16-bit complex FFT uses a radix algorithm. Single radix-8 1-stage, algorithm. The algorithm supports lengths of [16, 64, 256, 1024, 4096] and each length uses a different twiddle factor table.
void	nrf_dsp_cfft_radix4by2_i16 (const nrf_dsp_cfft_i16_t *p_cfft, int16_t *p_input)
	The fixed-point 16-bit complex FFT uses a mixed-radix algorithm. Multiple radix-4 stages are performed along with a radix-1 stage, as needed. The algorithm supports lengths of [32, 128, 512, 2048] and each length uses a different twiddle factor table.
uint16_t	nrf_dsp_rfft_twiddle_factors_i16 (int16_t *p_twiddle_rfft, uint16_t fft_len)
	Generate fixed-point 16 bit real twiddle factors buffer:
uint16_t	nrf_dsp_cfft_twiddle_factors_i16 (int16_t *p_twiddle_cfft, uint16_t fft_len)
	Generate fixed-point 16 bit complex twiddle factors buffer.

Detailed Description