www.pudn.com > x28x_FFT.rar > fftcd.c

/* ============================================================================== 
 
System Name:    Complex FFT - Software Test Bench (STB) 
 
File Name:      FFTCD.C 
 
Description:    Primary System file for demonstrating the Complex FFT module 
 
Originator:     Advanced Embeeded Control (AEC) - Texas Instruments 
 
Target dependency:  x28x 
 
Description: 
============ 
 
*/ 
 
#include  
#include  
 
/* Create an instance of Signal generator module    */ 
SGENTI_1 sgen = SGENTI_1_DEFAULTS; 
 
/* Create an instance of DATALOG Module             */ 
DLOG_4CH dlog=DLOG_4CH_DEFAULTS;       
     
/* Create an Instance of FFT module                 */ 
#define N   128 
#pragma DATA_SECTION(ipcb, "FFTipcb"); 
#pragma DATA_SECTION(mag, "FFTmag"); 
CFFT32  fft=CFFT32_128P_DEFAULTS;      
long ipcb[2*N]; 
long mag[N];  
 
/* Define window Co-efficient Array  and place the 
.constant section in ROM memory				*/ 
const long win[N/2]=HAMMING128; 
 
CFFT32_ACQ  acq=CFFT32_ACQ_DEFAULTS;         
     
int xn,yn; 
void main() 
{     
 
/* DATALOG module initialisation                    */         
       dlog.iptr1=&xn; 
       dlog.iptr2=&yn; 
       dlog.trig_value=0x800; 
       dlog.size=0x400;         /* Can log 1024 Samples                      */ 
       dlog.init(&dlog); 
 
/* Signal Generator module initialisation           */  
       sgen.offset=0; 
       sgen.gain=0x7fff;        /* gain=1 in Q15                              */ 
       sgen.freq=10000;         /* freq = (Required Freq/Max Freq)*2^15       */ 
                                /*      = (931/3051.7)*2^15 = 10000           */          
       sgen.step_max=10000;     /* Max Freq= (step_max * sampling freq)/65536 */ 
                                /* Max Freq = (10000*20k)/65536 = 3051.7      */ 
 
/* Initialize acquisition module                    */ 
        acq.buffptr=ipcb; 
        acq.tempptr=ipcb; 
        acq.size=N; 
        acq.count=N; 
        acq.acqflag=1; 
 
/* Initialize FFT module                            */ 
        fft.ipcbptr=ipcb; 
        fft.magptr=mag;   
        fft.winptr=(long *)win; 
        fft.init(&fft);   
 
/*--------------------------------------------------------------------------- 
    Nothing running in the background at present            
----------------------------------------------------------------------------*/ 
 
        while(1)  
        { 
            sgen.calc(&sgen); 
            xn=sgen.out; 
            yn=sgen.out; 
            dlog.update(&dlog); 
 
            acq.input=((unsigned long)xn)<<16; 
            acq.update(&acq);    
 
            if (acq.acqflag==0)     // If the samples are acquired       
            {    
                CFFT32_brev2(ipcb,ipcb,N); 
                CFFT32_brev2(ipcb,ipcb,N);  // Input samples in Real Part 
                fft.win(&fft);       
                CFFT32_brev2(ipcb,ipcb,N); 
                CFFT32_brev2(ipcb,ipcb,N);  // Input after windowing     
                fft.izero(&fft);  
                fft.calc(&fft); 
                fft.mag(&fft);  
                acq.acqflag=1;      // Enable the next acquisition           
            } 
 
        }        
 
} /* End: main() */