Hi
I am using CMSIS 3.2 library along with codewarrior 10.6, with FRDM-K20D50M board, In that I am using arm_cfft_f32(&arm_cfft_sR_f32_len16, testInput_f32_10khz, ifftFlag, doBitReverse); function present in arm_fft_bin_example_f32 which is present in CMSIS3.2 library(I reduced the size as it was overflowing the uc 's memory) In that when doBitReverse = 1 , The code hangs in the highlighted line of the following code which is present in the arm_cfft_f32.c . When doBitReverse = 0 , The code works except the bit reversal is not done. Kindly look into the issue
void arm_cfft_f32(
const arm_cfft_instance_f32 * S,
float32_t * p1,
uint8_t ifftFlag,
uint8_t bitReverseFlag)
{
uint32_t L = S->fftLen, l;
float32_t invL, * pSrc;
if(ifftFlag == 1u)
{
/* Conjugate input data */
pSrc = p1 + 1;
for(l=0; l<L; l++) {
*pSrc = -*pSrc;
pSrc += 2;
}
}
switch (L) {
case 16:
case 128:
case 1024:
arm_cfft_radix8by2_f32 ( (arm_cfft_instance_f32 *) S, p1);
break;
case 32:
case 256:
case 2048:
arm_cfft_radix8by4_f32 ( (arm_cfft_instance_f32 *) S, p1);
break;
case 64:
case 512:
case 4096:
arm_radix8_butterfly_f32( p1, L, (float32_t *) S->pTwiddle, 1);
break;
}
if( bitReverseFlag )
arm_bitreversal_32((uint32_t*)p1,S->bitRevLength,S->pBitRevTable);
if(ifftFlag == 1u)
{
invL = 1.0f/(float32_t)L;
/* Conjugate and scale output data */
pSrc = p1;
for(l=0; l<L; l++) {
*pSrc++ *= invL ;
*pSrc = -(*pSrc) * invL;
pSrc++;
}
}
}
in the debug window I captured the following result
entering the loop
hanged
i/p to CFFT function
The o/p of CFFT without bit reversal
Kind Regards
Amit Kumar
Original Attachment has been moved to: K20-CMSIS-Test-30-06-2014.zip
