Complex FFT F32

Macros
#define	FFTINIT(EXT, SIZE)
#define	CFFTINIT_F32(LEN, LENTWIDDLE)

Functions
void	riscv_cfft_f32 (const riscv_cfft_instance_f32 *S, float32_t *p1, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Processing function for the floating-point complex FFT. More...
	CFFTINIT_F32 (4096, 4096)
	Initialization function for the cfft f32 function with 4096 samples. More...
	CFFTINIT_F32 (2048, 1024)
	Initialization function for the cfft f32 function with 2048 samples. More...
	CFFTINIT_F32 (1024, 1024)
	Initialization function for the cfft f32 function with 1024 samples. More...
	CFFTINIT_F32 (512, 256)
	Initialization function for the cfft f32 function with 512 samples. More...
	CFFTINIT_F32 (256, 256)
	Initialization function for the cfft f32 function with 256 samples. More...
	CFFTINIT_F32 (128, 64)
	Initialization function for the cfft f32 function with 128 samples. More...
	CFFTINIT_F32 (64, 64)
	Initialization function for the cfft f32 function with 64 samples. More...
	CFFTINIT_F32 (32, 16)
	Initialization function for the cfft f32 function with 32 samples. More...
	CFFTINIT_F32 (16, 16)
	Initialization function for the cfft f32 function with 16 samples. More...
riscv_status	riscv_cfft_init_f32 (riscv_cfft_instance_f32 *S, uint16_t fftLen)
	Generic initialization function for the cfft f32 function. More...

Detailed Description

Macro Definition Documentation

CFFTINIT_F32

#define CFFTINIT_F32	(		LEN,
			LENTWIDDLE
	)

FFTINIT

#define FFTINIT	(		EXT,
			SIZE
	)

Function Documentation

CFFTINIT_F32() [1/9]

CFFTINIT_F32	(	1024	,
		1024
	)

Initialization function for the cfft f32 function with 1024 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [2/9]

CFFTINIT_F32	(	128	,
		64
	)

Initialization function for the cfft f32 function with 128 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [3/9]

CFFTINIT_F32	(	16	,
		16
	)

Initialization function for the cfft f32 function with 16 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [4/9]

CFFTINIT_F32	(	2048	,
		1024
	)

Initialization function for the cfft f32 function with 2048 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [5/9]

CFFTINIT_F32	(	256	,
		256
	)

Initialization function for the cfft f32 function with 256 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [6/9]

CFFTINIT_F32	(	32	,
		16
	)

Initialization function for the cfft f32 function with 32 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [7/9]

CFFTINIT_F32	(	4096	,
		4096
	)

Initialization function for the cfft f32 function with 4096 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [8/9]

CFFTINIT_F32	(	512	,
		256
	)

Initialization function for the cfft f32 function with 512 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

CFFTINIT_F32() [9/9]

CFFTINIT_F32	(	64	,
		64
	)

Initialization function for the cfft f32 function with 64 samples.

Parameters

[in,out]

S

points to an instance of the floating-point CFFT structure

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

riscv_cfft_f32()

void riscv_cfft_f32	(	const riscv_cfft_instance_f32 *	S,
		float32_t *	p1,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Processing function for the floating-point complex FFT.

Parameters

[in]	S	points to an instance of the floating-point CFFT structure
[in,out]	p1	points to the complex data buffer of size 2*fftLen. Processing occurs in-place
[in]	ifftFlag	flag that selects transform direction value = 0: forward transform value = 1: inverse transform
[in]	bitReverseFlag	flag that enables / disables bit reversal of output value = 0: disables bit reversal of output value = 1: enables bit reversal of output

Returns

none

riscv_cfft_init_f32()

riscv_status riscv_cfft_init_f32	(	riscv_cfft_instance_f32 *	S,
		uint16_t	fftLen
	)

Generic initialization function for the cfft f32 function.

Parameters

[in,out]	S	points to an instance of the floating-point CFFT structure
[in]	fftLen	fft length (number of complex samples)

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : an error is detected

Use of this function is mandatory only for the MVE version of the FFT.

Other versions can still initialize directly the data structure using variables declared in riscv_const_structs.h

This function should be used only if you don't know the FFT sizes that you'll need at build time. The use of this function will prevent the linker from removing the FFT tables that are not needed and the library code size will be bigger than needed.

If you use NMSIS-DSP as a static library, and if you know the FFT sizes that you need at build time, then it is better to use the initialization functions defined for each FFT size.