Complex FFT F32

void riscv_cfft_f32(const riscv_cfft_instance_f32 *S, float32_t *p1, uint8_t ifftFlag, uint8_t bitReverseFlag)
CFFTINIT_F32 (4096, 4096)
CFFTINIT_F32 (2048, 1024)
CFFTINIT_F32 (1024, 1024)
CFFTINIT_F32 (512, 256)
CFFTINIT_F32 (256, 256)
CFFTINIT_F32 (128, 64)
CFFTINIT_F32 (64, 64)
CFFTINIT_F32 (32, 16)
CFFTINIT_F32 (16, 16)
riscv_status riscv_cfft_init_f32(riscv_cfft_instance_f32 *S, uint16_t fftLen)
FFTINIT(EXT, SIZE)
CFFTINIT_F32(LEN, LENTWIDDLE)
group ComplexFFTF32

Defines

FFTINIT(EXT, SIZE)
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.

Parameters
  • S[in] points to an instance of the floating-point CFFT structure

  • p1[inout] points to the complex data buffer of size 2*fftLen. Processing occurs in-place

  • ifftFlag[in] flag that selects transform direction

    • value = 0: forward transform

    • value = 1: inverse transform

  • bitReverseFlag[in] flag that enables / disables bit reversal of output

    • value = 0: disables bit reversal of output

    • value = 1: enables bit reversal of output

Returns

none

CFFTINIT_F32 (4096, 4096)

Initialization function for the cfft f32 function with 4096 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (2048, 1024)

Initialization function for the cfft f32 function with 2048 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (1024, 1024)

Initialization function for the cfft f32 function with 1024 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (512, 256)

Initialization function for the cfft f32 function with 512 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (256, 256)

Initialization function for the cfft f32 function with 256 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (128, 64)

Initialization function for the cfft f32 function with 128 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (64, 64)

Initialization function for the cfft f32 function with 64 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (32, 16)

Initialization function for the cfft f32 function with 32 samples.

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

Parameters

S[inout] 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

CFFTINIT_F32 (16, 16)

Initialization function for the cfft f32 function with 16 samples.

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

Parameters

S[inout] 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

riscv_status riscv_cfft_init_f32(riscv_cfft_instance_f32 *S, uint16_t fftLen)

Generic initialization function for the cfft f32 function.

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.

Parameters
  • S[inout] points to an instance of the floating-point CFFT structure

  • fftLen[in] fft length (number of complex samples)

Returns

execution status

  • RISCV_MATH_SUCCESS : Operation successful

  • RISCV_MATH_ARGUMENT_ERROR : an error is detected