Deprecated Complex FFT functions

Functions
void	riscv_cfft_radix2_f16 (const riscv_cfft_radix2_instance_f16 *S, float16_t *pSrc)
	Radix-2 CFFT/CIFFT. More...
void	riscv_cfft_radix2_f32 (const riscv_cfft_radix2_instance_f32 *S, float32_t *pSrc)
	Radix-2 CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix2_init_f16 (riscv_cfft_radix2_instance_f16 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the floating-point CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix2_init_f32 (riscv_cfft_radix2_instance_f32 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the floating-point CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix2_init_q15 (riscv_cfft_radix2_instance_q15 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the Q15 CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix2_init_q31 (riscv_cfft_radix2_instance_q31 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the Q31 CFFT/CIFFT. More...
void	riscv_cfft_radix2_q15 (const riscv_cfft_radix2_instance_q15 *S, q15_t *pSrc)
	Processing function for the fixed-point CFFT/CIFFT. More...
void	riscv_cfft_radix2_q31 (const riscv_cfft_radix2_instance_q31 *S, q31_t *pSrc)
	Processing function for the fixed-point CFFT/CIFFT. More...
void	riscv_cfft_radix4by2_f16 (float16_t *pSrc, uint32_t fftLen, const float16_t *pCoef)
void	riscv_cfft_radix4_f16 (const riscv_cfft_radix4_instance_f16 *S, float16_t *pSrc)
	Processing function for the floating-point Radix-4 CFFT/CIFFT. More...
void	riscv_cfft_radix4_f32 (const riscv_cfft_radix4_instance_f32 *S, float32_t *pSrc)
	Processing function for the floating-point Radix-4 CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix4_init_f16 (riscv_cfft_radix4_instance_f16 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the floating-point CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix4_init_f32 (riscv_cfft_radix4_instance_f32 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the floating-point CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix4_init_q15 (riscv_cfft_radix4_instance_q15 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the Q15 CFFT/CIFFT. More...
riscv_status	riscv_cfft_radix4_init_q31 (riscv_cfft_radix4_instance_q31 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag)
	Initialization function for the Q31 CFFT/CIFFT. More...
void	riscv_cfft_radix4_q15 (const riscv_cfft_radix4_instance_q15 *S, q15_t *pSrc)
	Processing function for the Q15 CFFT/CIFFT. More...
void	riscv_cfft_radix4_q31 (const riscv_cfft_radix4_instance_q31 *S, q31_t *pSrc)
	Processing function for the Q31 CFFT/CIFFT. More...

Detailed Description

Function Documentation

riscv_cfft_radix2_f16()

void riscv_cfft_radix2_f16	(	const riscv_cfft_radix2_instance_f16 *	S,
		float16_t *	pSrc
	)

Radix-2 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_f16 and will be removed in the future

Parameters

[in]	S	points to an instance of the floating-point Radix-2 CFFT/CIFFT structure
[in,out]	pSrc	points to the complex data buffer of size 2*fftLen. Processing occurs in-place

Returns

none

riscv_cfft_radix2_f32()

void riscv_cfft_radix2_f32	(	const riscv_cfft_radix2_instance_f32 *	S,
		float32_t *	pSrc
	)

Radix-2 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_f32 and will be removed in the future

Parameters

[in]	S	points to an instance of the floating-point Radix-2 CFFT/CIFFT structure
[in,out]	pSrc	points to the complex data buffer of size 2*fftLen. Processing occurs in-place

Returns

none

riscv_cfft_radix2_init_f16()

riscv_status riscv_cfft_radix2_init_f16	(	riscv_cfft_radix2_instance_f16 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the floating-point CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_f16 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the floating-point CFFT/CIFFT structure
[in]	fftLen	length of the FFT
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix2_init_f32()

riscv_status riscv_cfft_radix2_init_f32	(	riscv_cfft_radix2_instance_f32 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the floating-point CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_f32 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the floating-point CFFT/CIFFT structure
[in]	fftLen	length of the FFT
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix2_init_q15()

riscv_status riscv_cfft_radix2_init_q15	(	riscv_cfft_radix2_instance_q15 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the Q15 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q15 and will be removed

Parameters

[in,out]	S	points to an instance of the Q15 CFFT/CIFFT structure.
[in]	fftLen	length of the FFT.
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix2_init_q31()

riscv_status riscv_cfft_radix2_init_q31	(	riscv_cfft_radix2_instance_q31 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the Q31 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q31 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the Q31 CFFT/CIFFT structure
[in]	fftLen	length of the FFT
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix2_q15()

void riscv_cfft_radix2_q15	(	const riscv_cfft_radix2_instance_q15 *	S,
		q15_t *	pSrc
	)

Processing function for the fixed-point CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q15 and will be removed in the future.

Parameters

[in]	S	points to an instance of the fixed-point CFFT/CIFFT structure
[in,out]	pSrc	points to the complex data buffer of size 2*fftLen. Processing occurs in-place

Returns

none

riscv_cfft_radix2_q31()

void riscv_cfft_radix2_q31	(	const riscv_cfft_radix2_instance_q31 *	S,
		q31_t *	pSrc
	)

Processing function for the fixed-point CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q31 and will be removed in the future.

Parameters

[in]	S	points to an instance of the fixed-point CFFT/CIFFT structure
[in,out]	pSrc	points to the complex data buffer of size 2*fftLen. Processing occurs in-place

Returns

none

riscv_cfft_radix4_f16()

void riscv_cfft_radix4_f16	(	const riscv_cfft_radix4_instance_f16 *	S,
		float16_t *	pSrc
	)

Processing function for the floating-point Radix-4 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_f16 and will be removed in the future.

Parameters

[in]	S	points to an instance of the floating-point Radix-4 CFFT/CIFFT structure
[in,out]	pSrc	points to the complex data buffer of size 2*fftLen. Processing occurs in-place

Returns

none

riscv_cfft_radix4_f32()

void riscv_cfft_radix4_f32	(	const riscv_cfft_radix4_instance_f32 *	S,
		float32_t *	pSrc
	)

Processing function for the floating-point Radix-4 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_f32 and will be removed in the future.

Parameters

[in]	S	points to an instance of the floating-point Radix-4 CFFT/CIFFT structure
[in,out]	pSrc	points to the complex data buffer of size 2*fftLen. Processing occurs in-place

Returns

none

riscv_cfft_radix4_init_f16()

riscv_status riscv_cfft_radix4_init_f16	(	riscv_cfft_radix4_instance_f16 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the floating-point CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superceded by riscv_cfft_f16 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the floating-point CFFT/CIFFT structure
[in]	fftLen	length of the FFT
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix4_init_f32()

riscv_status riscv_cfft_radix4_init_f32	(	riscv_cfft_radix4_instance_f32 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the floating-point CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superceded by riscv_cfft_f32 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the floating-point CFFT/CIFFT structure
[in]	fftLen	length of the FFT
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix4_init_q15()

riscv_status riscv_cfft_radix4_init_q15	(	riscv_cfft_radix4_instance_q15 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the Q15 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q15 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the Q15 CFFT/CIFFT structure
[in]	fftLen	length of the FFT
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix4_init_q31()

riscv_status riscv_cfft_radix4_init_q31	(	riscv_cfft_radix4_instance_q31 *	S,
		uint16_t	fftLen,
		uint8_t	ifftFlag,
		uint8_t	bitReverseFlag
	)

Initialization function for the Q31 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q31 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the Q31 CFFT/CIFFT structure.
[in]	fftLen	length of the FFT.
[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

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLen is not a supported length

Details

The parameter ifftFlag controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

The parameter fftLen Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.

This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.

riscv_cfft_radix4_q15()

void riscv_cfft_radix4_q15	(	const riscv_cfft_radix4_instance_q15 *	S,
		q15_t *	pSrc
	)

Processing function for the Q15 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q15 and will be removed in the future.

Parameters

[in]	S	points to an instance of the Q15 CFFT/CIFFT structure.
[in,out]	pSrc	points to the complex data buffer. Processing occurs in-place.

Returns

none

Input and output formats:

Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process. Hence the output format is different for different FFT sizes. The input and output formats for different FFT sizes and number of bits to upscale are mentioned in the tables below for CFFT and CIFFT:

CFFT Size	Input format	Output format	Number of bits to upscale
16	1.15	5.11	4
64	1.15	7.9	6
256	1.15	9.7	8
1024	1.15	11.5	10

CIFFT Size	Input format	Output format	Number of bits to upscale
16	1.15	5.11	0
64	1.15	7.9	0
256	1.15	9.7	0
1024	1.15	11.5	0

riscv_cfft_radix4_q31()

void riscv_cfft_radix4_q31	(	const riscv_cfft_radix4_instance_q31 *	S,
		q31_t *	pSrc
	)

Processing function for the Q31 CFFT/CIFFT.

Deprecated:

Do not use this function. It has been superseded by riscv_cfft_q31 and will be removed in the future.

Parameters

[in]	S	points to an instance of the Q31 CFFT/CIFFT structure
[in,out]	pSrc	points to the complex data buffer of size 2*fftLen. Processing occurs in-place

Returns

none

Input and output formats:

Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process. Hence the output format is different for different FFT sizes. The input and output formats for different FFT sizes and number of bits to upscale are mentioned in the tables below for CFFT and CIFFT:

CFFT Size	Input format	Output format	Number of bits to upscale
16	1.31	5.27	4
64	1.31	7.25	6
256	1.31	9.23	8
1024	1.31	11.21	10

CIFFT Size	Input format	Output format	Number of bits to upscale
16	1.31	5.27	0
64	1.31	7.25	0
256	1.31	9.23	0
1024	1.31	11.21	0

riscv_cfft_radix4by2_f16()

void riscv_cfft_radix4by2_f16	(	float16_t *	pSrc,
		uint32_t	fftLen,
		const float16_t *	pCoef
	)