CMSIS-DSP  Version 1.7.0
CMSIS DSP Software Library
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Variables
Complex FFT Tables
Complex FFT Functions

Variables

const uint16_t armBitRevTable [1024]
 Table for bit reversal process. More...
 
const float32_t twiddleCoef_16 [32]
 Floating-point Twiddle factors Table Generation. More...
 
const float32_t twiddleCoef_32 [64]
 
const float32_t twiddleCoef_64 [128]
 
const float32_t twiddleCoef_128 [256]
 
const float32_t twiddleCoef_256 [512]
 
const float32_t twiddleCoef_512 [1024]
 
const float32_t twiddleCoef_1024 [2048]
 
const float32_t twiddleCoef_2048 [4096]
 
const float32_t twiddleCoef_4096 [8192]
 
const q31_t twiddleCoef_16_q31 [24]
 Q31 Twiddle factors Table. More...
 
const q31_t twiddleCoef_32_q31 [48]
 
const q31_t twiddleCoef_64_q31 [96]
 
const q31_t twiddleCoef_128_q31 [192]
 
const q31_t twiddleCoef_256_q31 [384]
 
const q31_t twiddleCoef_512_q31 [768]
 
const q31_t twiddleCoef_1024_q31 [1536]
 
const q31_t twiddleCoef_2048_q31 [3072]
 
const q31_t twiddleCoef_4096_q31 [6144]
 
const q15_t twiddleCoef_16_q15 [24]
 q15 Twiddle factors Table More...
 
const q15_t twiddleCoef_32_q15 [48]
 
const q15_t twiddleCoef_64_q15 [96]
 
const q15_t twiddleCoef_128_q15 [192]
 
const q15_t twiddleCoef_256_q15 [384]
 
const q15_t twiddleCoef_512_q15 [768]
 
const q15_t twiddleCoef_1024_q15 [1536]
 
const q15_t twiddleCoef_2048_q15 [3072]
 
const q15_t twiddleCoef_4096_q15 [6144]
 

Description

Variable Documentation

const uint16_t armBitRevTable[1024]
Pseudo code for Generation of Bit reversal Table is 
for (l = 1; l <= N/4; l++)
{
  for (i = 0; i< logN2; i++)
  {
    a[i] = l & (1 << i);
  }
  for (j = 0; j < logN2; j++)
  {
    if (a[j] != 0)
    y[l] += (1 << ((logN2 - 1) - j));
  }
  y[l] = y[l] >> 1;
 }
where N = 4096, logN2 = 12
N is the maximum FFT Size supported
const float32_t twiddleCoef_1024[2048]
Example code for Floating-point Twiddle factors Generation: 
for (i = 0; i< N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 1024, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_1024_q15[1536]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 1024, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_1024_q31[1536]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 1024, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_128[256]
Example code for Floating-point Twiddle factors Generation: 
for (i = 0; i< N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 128, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_128_q15[192]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 128, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_128_q31[192]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i < 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 128, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_16[32]
Example code for Floating-point Twiddle factors Generation: 
for (i = 0; i < N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 16, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_16_q15[24]
Example code for q15 Twiddle factors Generation:: 
fori = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 16, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_16_q31[24]
Example code for Q31 Twiddle factors Generation:: 
 for(i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 16, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_2048[4096]
Example code for Floating-point Twiddle factors Generation: 
for (i = 0; i< N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 2048, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_2048_q15[3072]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 2048, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_2048_q31[3072]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 2048, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_256[512]
Example code for Floating-point Twiddle factors Generation: 
for(i = 0; i< N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 256, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_256_q15[384]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 256, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_256_q31[384]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 256, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_32[64]
Example code for Floating-point Twiddle factors Generation: 
for (i = 0; i< N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 32, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_32_q15[48]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 32, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_32_q31[48]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 32, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_4096[8192]
Example code for Floating-point Twiddle factors Generation: 
for (i = 0; i< N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 4096, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_4096_q15[6144]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 4096, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_4096_q31[6144]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 4096, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_512[1024]
Example code for Floating-point Twiddle factors Generation: 
for (i = 0; i< N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 512, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_512_q15[768]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 512, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_512_q31[768]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 512, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))
const float32_t twiddleCoef_64[128]
Example code for Floating-point Twiddle factors Generation: 
for(i = 0; i < N/; i++)
{
      twiddleCoef[2*i]   = cos(i * 2*PI/(float)N);
      twiddleCoef[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 64, PI = 3.14159265358979
Cos and Sin values are in interleaved fashion
const q15_t twiddleCoef_64_q15[96]
Example code for q15 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefq15[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefq15[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 64, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to q15(Fixed point 1.15): round(twiddleCoefq15(i) * pow(2, 15))
const q31_t twiddleCoef_64_q31[96]
Example code for Q31 Twiddle factors Generation:: 
for (i = 0; i< 3N/4; i++)
{
   twiddleCoefQ31[2*i]   = cos(i * 2*PI/(float)N);
   twiddleCoefQ31[2*i+1] = sin(i * 2*PI/(float)N);
}
where N = 64, PI = 3.14159265358979
Cos and Sin values are interleaved fashion
Convert Floating point to Q31(Fixed point 1.31): round(twiddleCoefQ31(i) * pow(2, 31))