stm32的DSP

void arm_cfft_f32 ( const arm_cfft_instance_f32 * S,
float32_t * p1,
uint8_t ifftFlag,
uint8_t bitReverseFlag
)

s:points to an instance of the floating-point CFFT structure //指向浮點CFFT結構體
p1: points to the complex data buffer of size 2fftLen. Processing occurs in-place //指向2fftLen大小的複數緩衝
ifftFlag：flag that selects transform direction //選擇變化的方向標誌
bitReverseFlag : flag that enables / disables bit reversal of output// 開斷位方向輸出
/
typedef struct
{
uint16_t fftLen; /**< length of the FFT. fftd的長度/
const float32_t *pTwiddle; /< points to the Twiddle factor table.指向旋轉因數表 */
const uint16_t *pBitRevTable; /< points to the bit reversal table.指向位反向表 /
uint16_t bitRevLength; /**< bit reversal table length. 位反向長度/
} arm_cfft_instance_f32;