Texas Instruments C28 Series User Manual

Function Descriptions
Example:
The following sample code obtains the FFT of the real input.
#include "FPU.h"
#define RFFT_STAGES 9
#define RFFT_SIZE (1 << RFFT_STAGES)
RFFT_ADC_F32_STRUCT rfft_adc;
RFFT_F32_STRUCT rfft;
/
*
RFFTin1Buff section to 2
*
FFT_SIZE in the linker file
*
/
#pragma DATA_SECTION(RFFTin1Buff,"RFFTdata1");
float32 RFFTin1Buff[RFFT_SIZE];
#pragma DATA_SECTION(RFFToutBuff,"RFFTdata2");
float32 RFFToutBuff[RFFT_SIZE];
#pragma DATA_SECTION(RFFTmagBuff,"RFFTdata3");
float32 RFFTmagBuff[RFFT_SIZE/2+1];
#pragma DATA_SECTION(RFFTF32Coef,"RFFTdata4");
float32 RFFTF32Coef[RFFT_SIZE];
main()
{
rfft_adc.Tail = &rfft.OutBuf; /
*
Tail is passed to OutBuf
*
/
rfft.FFTSize = RFFT_SIZE; /
*
FFT size
*
/
rfft.FFTStages = RFFT_STAGES; /
*
FFT stages
*
/
rfft_adc.InBuf = &RFFTin1Buff[0]; /
*
Input buffer 12-bit ADC input
*
/
rfft.OutBuf = &RFFToutBuff[0]; /
*
Output buffer
*
/
rfft.CosSinBuf = &RFFTF32Coef[0]; /
*
Twiddle factor
*
/
rfft.MagBuf = &RFFTmagBuff[0]; /
*
Magnitude output buffer
*
/
... ...
RFFT_f32_sincostable(&rfft) /
*
Initialize twiddle buffer
*
/
RFFT_adc_f32u(&rfft); /
*
Calculate output
*
/
}
Benchmark Information:
The following table provides benchmark numbers for the function:
FFTSize C-Callable ASM (Cycle Count)
32 698
64 1444
128 3102
256 6792
512 14962
1024 31387
2048 68549
Table 3.17: Benchmark Information
Sep 10, 2012 37

Texas Instruments C28 Series Specifications

General

Brand	Texas Instruments
Model	C28 Series
Category	Computer Hardware
Language	English