Complex FFT F32

Functions
void	arm_cfft_f32 (const arm_cfft_instance_f32 *S, float32_t *p1, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Processing function for the floating-point complex FFT.
arm_status	arm_cfft_init_4096_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 4096 samples.
arm_status	arm_cfft_init_2048_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 2048 samples.
arm_status	arm_cfft_init_1024_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 1024 samples.
arm_status	arm_cfft_init_512_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 512 samples.
arm_status	arm_cfft_init_256_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 256 samples.
arm_status	arm_cfft_init_128_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 128 samples.
arm_status	arm_cfft_init_64_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 64 samples.
arm_status	arm_cfft_init_32_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 32 samples.
arm_status	arm_cfft_init_16_f32 (arm_cfft_instance_f32 *S)
	Initialization function for the cfft f32 function with 16 samples.
arm_status	arm_cfft_init_f32 (arm_cfft_instance_f32 *S, uint16_t fftLen)
	Generic initialization function for the cfft f32 function.

Description

Function Documentation

arm_cfft_f32()

void arm_cfft_f32	(	const arm_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

arm_cfft_init_1024_f32()

arm_status arm_cfft_init_1024_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_128_f32()

arm_status arm_cfft_init_128_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_16_f32()

arm_status arm_cfft_init_16_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_2048_f32()

arm_status arm_cfft_init_2048_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_256_f32()

arm_status arm_cfft_init_256_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_32_f32()

arm_status arm_cfft_init_32_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_4096_f32()

arm_status arm_cfft_init_4096_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_512_f32()

arm_status arm_cfft_init_512_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_64_f32()

arm_status arm_cfft_init_64_f32

(

arm_cfft_instance_f32 *

S

)

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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_const_structs.h

arm_cfft_init_f32()

arm_status arm_cfft_init_f32	(	arm_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

• ARM_MATH_SUCCESS : Operation successful
• ARM_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 arm_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 CMSIS-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.