CSI-DSP  Version 1.0.0
CSI DSP Software Library
Functions
csky_cfft_radix4_q15.c File Reference

Functions

void csky_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 csky_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 csky_bitreversal_q15 (q15_t *pSrc, uint32_t fftLen, uint16_t bitRevFactor, uint16_t *pBitRevTab)
 
void csky_cfft_radix4_q15 (const csky_cfft_radix4_instance_q15 *S, q15_t *pSrc)
 Processing function for the Q15 CFFT/CIFFT. More...
 

Function Documentation

void csky_bitreversal_q15 ( q15_t pSrc,
uint32_t  fftLen,
uint16_t  bitRevFactor,
uint16_t *  pBitRevTab 
)
void csky_cfft_radix4_q15 ( const csky_cfft_radix4_instance_q15 S,
q15_t pSrc 
)
Deprecated:
Do not use this function. It has been superseded by csky_cfft_q15 and will be removed
Parameters
[in]*Spoints to an instance of the Q15 CFFT/CIFFT structure.
[in,out]*pSrcpoints 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:
void csky_radix4_butterfly_inverse_q15 ( q15_t pSrc16,
uint32_t  fftLen,
q15_t pCoef16,
uint32_t  twidCoefModifier 
)
Parameters
[in,out]*pSrc16points to the in-place buffer of Q15 data type.
[in]fftLenlength of the FFT.
[in]*pCoef16points to twiddle coefficient buffer.
[in]twidCoefModifiertwiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
Returns
none.
void csky_radix4_butterfly_q15 ( q15_t pSrc16,
uint32_t  fftLen,
q15_t pCoef16,
uint32_t  twidCoefModifier 
)
Parameters
[in,out]*pSrc16points to the in-place buffer of Q15 data type.
[in]fftLenlength of the FFT.
[in]*pCoef16points to twiddle coefficient buffer.
[in]twidCoefModifiertwiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
Returns
none.