CMSIS-DSP: arm_rfft_q15.c File Reference

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arm_rfft_q15.c File Reference

## Functions

void | arm_radix4_butterfly_q15 (q15_t *pSrc16, uint32_t fftLen, q15_t *pCoef16, uint32_t twidCoefModifier)
| Core function for the Q15 CFFT butterfly process. More...
void | arm_radix4_butterfly_inverse_q15 (q15_t *pSrc16, uint32_t fftLen, q15_t *pCoef16, uint32_t twidCoefModifier)
| Core function for the Q15 CIFFT butterfly process. More...
void | arm_bitreversal_q15 (q15_t *pSrc, uint32_t fftLen, uint16_t bitRevFactor, uint16_t *pBitRevTab)
void | arm_split_rfft_q15 (q15_t *pSrc, uint32_t fftLen, q15_t *pATable, q15_t *pBTable, q15_t *pDst, uint32_t modifier)
| Core Real FFT process. More...
void | arm_split_rifft_q15 (q15_t *pSrc, uint32_t fftLen, q15_t *pATable, q15_t *pBTable, q15_t *pDst, uint32_t modifier)
| Core Real IFFT process. More...
void | arm_rfft_q15 (const arm_rfft_instance_q15 *S, q15_t *pSrc, q15_t *pDst)
| Processing function for the Q15 RFFT/RIFFT. More...

## Function Documentation

void arm_bitreversal_q15 | ( | q15_t * | pSrc,
|  | uint32_t | fftLen,
|  | uint16_t | bitRevFactor,
|  | uint16_t * | pBitRevTab
| ) |  |

Referenced by arm_cfft_radix2_q15(), arm_cfft_radix4_q15(), and arm_rfft_q15().

void arm_radix4_butterfly_inverse_q15 | ( | q15_t * | pSrc16,
|  | uint32_t | fftLen,
|  | q15_t * | pCoef16,
|  | uint32_t | twidCoefModifier
| ) |  |

Parameters

  [in,out] | *pSrc16 | points to the in-place buffer of Q15 data type.
  [in] | fftLen | length of the FFT.
  [in] | *pCoef16 | points to twiddle coefficient buffer.
  [in] | twidCoefModifier | twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.

Returns
  none.

References __SIMD32, and _SIMD32_OFFSET.

Referenced by arm_cfft_radix4_q15(), and arm_rfft_q15().

void arm_radix4_butterfly_q15 | ( | q15_t * | pSrc16,
|  | uint32_t | fftLen,
|  | q15_t * | pCoef16,
|  | uint32_t | twidCoefModifier
| ) |  |

end of ComplexFFT group

Parameters

  [in,out] | *pSrc16 | points to the in-place buffer of Q15 data type.
  [in] | fftLen | length of the FFT.
  [in] | *pCoef16 | points to twiddle coefficient buffer.
  [in] | twidCoefModifier | twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.

Returns
  none.

References __SIMD32, and _SIMD32_OFFSET.

Referenced by arm_cfft_radix4_q15(), and arm_rfft_q15().

void arm_split_rfft_q15 | ( | q15_t * | pSrc,
|  | uint32_t | fftLen,
|  | q15_t * | pATable,
|  | q15_t * | pBTable,
|  | q15_t * | pDst,
|  | uint32_t | modifier
| ) |  |

end of RealFFT group

Parameters

  *pSrc | points to the input buffer.
  fftLen | length of FFT.
  *pATable | points to the A twiddle Coef buffer.
  *pBTable | points to the B twiddle Coef buffer.
  *pDst | points to the output buffer.
  modifier | twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.

Returns
  none. The function implements a Real FFT

References __SIMD32.

Referenced by arm_rfft_q15().

void arm_split_rifft_q15 | ( | q15_t * | pSrc,
|  | uint32_t | fftLen,
|  | q15_t * | pATable,
|  | q15_t * | pBTable,
|  | q15_t * | pDst,
|  | uint32_t | modifier
| ) |  |

Parameters

  [in] | *pSrc | points to the input buffer.
  [in] | fftLen | length of FFT.
  [in] | *pATable | points to the twiddle Coef A buffer.
  [in] | *pBTable | points to the twiddle Coef B buffer.
  [out] | *pDst | points to the output buffer.
  [in] | modifier | twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.

Returns
  none. The function implements a Real IFFT

References __SIMD32.

Referenced by arm_rfft_q15().