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CMSIS-DSP
Version 1.4.2
CMSIS DSP Software Library
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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. | |
void | arm_cfft_radix2_f32 (const arm_cfft_radix2_instance_f32 *S, float32_t *pSrc) |
Radix-2 CFFT/CIFFT. | |
arm_status | arm_cfft_radix2_init_f32 (arm_cfft_radix2_instance_f32 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag) |
Initialization function for the floating-point CFFT/CIFFT. | |
arm_status | arm_cfft_radix2_init_q15 (arm_cfft_radix2_instance_q15 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag) |
Initialization function for the Q15 CFFT/CIFFT. | |
arm_status | arm_cfft_radix2_init_q31 (arm_cfft_radix2_instance_q31 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag) |
Initialization function for the Q31 CFFT/CIFFT. | |
void | arm_cfft_radix2_q15 (const arm_cfft_radix2_instance_q15 *S, q15_t *pSrc) |
Processing function for the fixed-point CFFT/CIFFT. | |
void | arm_cfft_radix2_q31 (const arm_cfft_radix2_instance_q31 *S, q31_t *pSrc) |
Processing function for the fixed-point CFFT/CIFFT. | |
void | arm_cfft_radix4_f32 (const arm_cfft_radix4_instance_f32 *S, float32_t *pSrc) |
Processing function for the floating-point Radix-4 CFFT/CIFFT. | |
arm_status | arm_cfft_radix4_init_f32 (arm_cfft_radix4_instance_f32 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag) |
Initialization function for the floating-point CFFT/CIFFT. | |
arm_status | arm_cfft_radix4_init_q15 (arm_cfft_radix4_instance_q15 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag) |
Initialization function for the Q15 CFFT/CIFFT. | |
arm_status | arm_cfft_radix4_init_q31 (arm_cfft_radix4_instance_q31 *S, uint16_t fftLen, uint8_t ifftFlag, uint8_t bitReverseFlag) |
Initialization function for the Q31 CFFT/CIFFT. | |
void | arm_cfft_radix4_q15 (const arm_cfft_radix4_instance_q15 *S, q15_t *pSrc) |
Processing function for the Q15 CFFT/CIFFT. | |
void | arm_cfft_radix4_q31 (const arm_cfft_radix4_instance_q31 *S, q31_t *pSrc) |
Processing function for the Q31 CFFT/CIFFT. | |
2*fftLen
interleaved values as shown below. {real[0], imag[0], real[1], imag[1],..}The FFT result will be contained in the same array and the frequency domain values will have the same interleaving.
fftLen
when computing the forward transform. The inverse transform includes a scale of 1/fftLen
as part of the calculation and this matches the textbook definition of the inverse FFT. arm_const_structs.h
. Include this header in your function and then pass one of the constant structures as an argument to arm_cfft_f32. For example: arm_cfft_f32(arm_cfft_sR_f32_len64, pSrc, 1, 1)
1/fftLen
as compared to the standard textbook definition of the FFT. The inverse FFT also scales down during each butterfly stage and this corresponds to the standard textbook definition. *arm_cfft_radix2_instance_q31 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor}; *arm_cfft_radix2_instance_q15 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor}; *arm_cfft_radix4_instance_q31 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor}; *arm_cfft_radix4_instance_q15 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor}; *arm_cfft_instance_f32 S = {fftLen, pTwiddle, pBitRevTable, bitRevLength};
fftLen
length of CFFT/CIFFT; ifftFlag
Flag for selection of forward or inverse transform. When ifftFlag is set the inverse transform is calculated. bitReverseFlag
Flag for selection of output order (Set bitReverseFlag to output in normal order otherwise output in bit reversed order); pTwiddle
points to array of twiddle coefficients; pBitRevTable
points to the bit reversal table. twidCoefModifier
modifier for twiddle factor table which supports all FFT lengths with same table; pBitRevTable
modifier for bit reversal table which supports all FFT lengths with same table. onebyfftLen
value of 1/fftLen to calculate CIFFT; void arm_cfft_f32 | ( | const arm_cfft_instance_f32 * | S, |
float32_t * | p1, | ||
uint8_t | ifftFlag, | ||
uint8_t | bitReverseFlag | ||
) |
[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 forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
[in] | bitReverseFlag | flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
References arm_bitreversal_32(), arm_cfft_radix8by2_f32(), arm_cfft_radix8by4_f32(), arm_radix8_butterfly_f32(), arm_cfft_instance_f32::bitRevLength, arm_cfft_instance_f32::fftLen, arm_cfft_instance_f32::pBitRevTable, and arm_cfft_instance_f32::pTwiddle.
Referenced by arm_rfft_fast_f32(), and main().
void arm_cfft_radix2_f32 | ( | const arm_cfft_radix2_instance_f32 * | S, |
float32_t * | pSrc | ||
) |
[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. |
References arm_bitreversal_f32(), arm_radix2_butterfly_f32(), arm_radix2_butterfly_inverse_f32(), arm_cfft_radix2_instance_f32::bitReverseFlag, arm_cfft_radix2_instance_f32::bitRevFactor, arm_cfft_radix2_instance_f32::fftLen, arm_cfft_radix2_instance_f32::ifftFlag, arm_cfft_radix2_instance_f32::onebyfftLen, arm_cfft_radix2_instance_f32::pBitRevTable, arm_cfft_radix2_instance_f32::pTwiddle, and arm_cfft_radix2_instance_f32::twidCoefModifier.
arm_status arm_cfft_radix2_init_f32 | ( | arm_cfft_radix2_instance_f32 * | S, |
uint16_t | fftLen, | ||
uint8_t | ifftFlag, | ||
uint8_t | bitReverseFlag | ||
) |
[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 forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
[in] | bitReverseFlag | flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
fftLen
is not a supported value.ifftFlag
controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated 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. fftLen
Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. References ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, armBitRevTable, arm_cfft_radix2_instance_f32::bitReverseFlag, arm_cfft_radix2_instance_f32::bitRevFactor, arm_cfft_radix2_instance_f32::fftLen, ifftFlag, arm_cfft_radix2_instance_f32::ifftFlag, arm_cfft_radix2_instance_f32::onebyfftLen, arm_cfft_radix2_instance_f32::pBitRevTable, arm_cfft_radix2_instance_f32::pTwiddle, status, arm_cfft_radix2_instance_f32::twidCoefModifier, and twiddleCoef.
arm_status arm_cfft_radix2_init_q15 | ( | arm_cfft_radix2_instance_q15 * | S, |
uint16_t | fftLen, | ||
uint8_t | ifftFlag, | ||
uint8_t | bitReverseFlag | ||
) |
[in,out] | *S | points to an instance of the Q15 CFFT/CIFFT structure. |
[in] | fftLen | length of the FFT. |
[in] | ifftFlag | flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
[in] | bitReverseFlag | flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
fftLen
is not a supported value.ifftFlag
controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated 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. fftLen
Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. References ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, armBitRevTable, arm_cfft_radix2_instance_q15::bitReverseFlag, arm_cfft_radix2_instance_q15::bitRevFactor, arm_cfft_radix2_instance_q15::fftLen, ifftFlag, arm_cfft_radix2_instance_q15::ifftFlag, arm_cfft_radix2_instance_q15::pBitRevTable, arm_cfft_radix2_instance_q15::pTwiddle, status, arm_cfft_radix2_instance_q15::twidCoefModifier, and twiddleCoefQ15.
arm_status arm_cfft_radix2_init_q31 | ( | arm_cfft_radix2_instance_q31 * | S, |
uint16_t | fftLen, | ||
uint8_t | ifftFlag, | ||
uint8_t | bitReverseFlag | ||
) |
[in,out] | *S | points to an instance of the Q31 CFFT/CIFFT structure. |
[in] | fftLen | length of the FFT. |
[in] | ifftFlag | flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
[in] | bitReverseFlag | flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
fftLen
is not a supported value.ifftFlag
controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated 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. fftLen
Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. References ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, armBitRevTable, arm_cfft_radix2_instance_q31::bitReverseFlag, arm_cfft_radix2_instance_q31::bitRevFactor, arm_cfft_radix2_instance_q31::fftLen, ifftFlag, arm_cfft_radix2_instance_q31::ifftFlag, arm_cfft_radix2_instance_q31::pBitRevTable, arm_cfft_radix2_instance_q31::pTwiddle, status, arm_cfft_radix2_instance_q31::twidCoefModifier, and twiddleCoefQ31.
void arm_cfft_radix2_q15 | ( | const arm_cfft_radix2_instance_q15 * | S, |
q15_t * | pSrc | ||
) |
[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. |
References arm_bitreversal_q15(), arm_radix2_butterfly_inverse_q15(), arm_radix2_butterfly_q15(), arm_cfft_radix2_instance_q15::bitRevFactor, arm_cfft_radix2_instance_q15::fftLen, arm_cfft_radix2_instance_q15::ifftFlag, arm_cfft_radix2_instance_q15::pBitRevTable, arm_cfft_radix2_instance_q15::pTwiddle, and arm_cfft_radix2_instance_q15::twidCoefModifier.
void arm_cfft_radix2_q31 | ( | const arm_cfft_radix2_instance_q31 * | S, |
q31_t * | pSrc | ||
) |
[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. |
References arm_bitreversal_q31(), arm_radix2_butterfly_inverse_q31(), arm_radix2_butterfly_q31(), arm_cfft_radix2_instance_q31::bitRevFactor, arm_cfft_radix2_instance_q31::fftLen, arm_cfft_radix2_instance_q31::ifftFlag, arm_cfft_radix2_instance_q31::pBitRevTable, arm_cfft_radix2_instance_q31::pTwiddle, and arm_cfft_radix2_instance_q31::twidCoefModifier.
void arm_cfft_radix4_f32 | ( | const arm_cfft_radix4_instance_f32 * | S, |
float32_t * | pSrc | ||
) |
[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. |
References arm_bitreversal_f32(), arm_radix4_butterfly_f32(), arm_radix4_butterfly_inverse_f32(), arm_cfft_radix4_instance_f32::bitReverseFlag, arm_cfft_radix4_instance_f32::bitRevFactor, arm_cfft_radix4_instance_f32::fftLen, arm_cfft_radix4_instance_f32::ifftFlag, arm_cfft_radix4_instance_f32::onebyfftLen, arm_cfft_radix4_instance_f32::pBitRevTable, arm_cfft_radix4_instance_f32::pTwiddle, and arm_cfft_radix4_instance_f32::twidCoefModifier.
Referenced by main().
arm_status arm_cfft_radix4_init_f32 | ( | arm_cfft_radix4_instance_f32 * | S, |
uint16_t | fftLen, | ||
uint8_t | ifftFlag, | ||
uint8_t | bitReverseFlag | ||
) |
[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 forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
[in] | bitReverseFlag | flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
fftLen
is not a supported value.ifftFlag
controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated 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. fftLen
Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. References ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, armBitRevTable, arm_cfft_radix4_instance_f32::bitReverseFlag, arm_cfft_radix4_instance_f32::bitRevFactor, arm_cfft_radix4_instance_f32::fftLen, ifftFlag, arm_cfft_radix4_instance_f32::ifftFlag, arm_cfft_radix4_instance_f32::onebyfftLen, arm_cfft_radix4_instance_f32::pBitRevTable, arm_cfft_radix4_instance_f32::pTwiddle, status, arm_cfft_radix4_instance_f32::twidCoefModifier, and twiddleCoef.
Referenced by arm_rfft_init_f32(), and main().
arm_status arm_cfft_radix4_init_q15 | ( | arm_cfft_radix4_instance_q15 * | S, |
uint16_t | fftLen, | ||
uint8_t | ifftFlag, | ||
uint8_t | bitReverseFlag | ||
) |
[in,out] | *S | points to an instance of the Q15 CFFT/CIFFT structure. |
[in] | fftLen | length of the FFT. |
[in] | ifftFlag | flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
[in] | bitReverseFlag | flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
fftLen
is not a supported value.ifftFlag
controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated 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. fftLen
Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. References ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, armBitRevTable, arm_cfft_radix4_instance_q15::bitReverseFlag, arm_cfft_radix4_instance_q15::bitRevFactor, arm_cfft_radix4_instance_q15::fftLen, ifftFlag, arm_cfft_radix4_instance_q15::ifftFlag, arm_cfft_radix4_instance_q15::pBitRevTable, arm_cfft_radix4_instance_q15::pTwiddle, status, arm_cfft_radix4_instance_q15::twidCoefModifier, and twiddleCoefQ15.
Referenced by arm_rfft_init_q15().
arm_status arm_cfft_radix4_init_q31 | ( | arm_cfft_radix4_instance_q31 * | S, |
uint16_t | fftLen, | ||
uint8_t | ifftFlag, | ||
uint8_t | bitReverseFlag | ||
) |
[in,out] | *S | points to an instance of the Q31 CFFT/CIFFT structure. |
[in] | fftLen | length of the FFT. |
[in] | ifftFlag | flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
[in] | bitReverseFlag | flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
fftLen
is not a supported value.ifftFlag
controls whether a forward or inverse transform is computed. Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated 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. fftLen
Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. References ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, armBitRevTable, arm_cfft_radix4_instance_q31::bitReverseFlag, arm_cfft_radix4_instance_q31::bitRevFactor, arm_cfft_radix4_instance_q31::fftLen, ifftFlag, arm_cfft_radix4_instance_q31::ifftFlag, arm_cfft_radix4_instance_q31::pBitRevTable, arm_cfft_radix4_instance_q31::pTwiddle, status, arm_cfft_radix4_instance_q31::twidCoefModifier, and twiddleCoefQ31.
Referenced by arm_rfft_init_q31().
void arm_cfft_radix4_q15 | ( | const arm_cfft_radix4_instance_q15 * | S, |
q15_t * | pSrc | ||
) |
[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. |
References arm_bitreversal_q15(), arm_radix4_butterfly_inverse_q15(), arm_radix4_butterfly_q15(), arm_cfft_radix4_instance_q15::bitReverseFlag, arm_cfft_radix4_instance_q15::bitRevFactor, arm_cfft_radix4_instance_q15::fftLen, arm_cfft_radix4_instance_q15::ifftFlag, arm_cfft_radix4_instance_q15::pBitRevTable, arm_cfft_radix4_instance_q15::pTwiddle, and arm_cfft_radix4_instance_q15::twidCoefModifier.
void arm_cfft_radix4_q31 | ( | const arm_cfft_radix4_instance_q31 * | S, |
q31_t * | pSrc | ||
) |
[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. |
References arm_bitreversal_q31(), arm_radix4_butterfly_inverse_q31(), arm_radix4_butterfly_q31(), arm_cfft_radix4_instance_q31::bitReverseFlag, arm_cfft_radix4_instance_q31::bitRevFactor, arm_cfft_radix4_instance_q31::fftLen, arm_cfft_radix4_instance_q31::ifftFlag, arm_cfft_radix4_instance_q31::pBitRevTable, arm_cfft_radix4_instance_q31::pTwiddle, and arm_cfft_radix4_instance_q31::twidCoefModifier.