diff options
Diffstat (limited to 'FFT_Test/fft_old.hcc')
| -rw-r--r-- | FFT_Test/fft_old.hcc | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/FFT_Test/fft_old.hcc b/FFT_Test/fft_old.hcc new file mode 100644 index 0000000..5c106bf --- /dev/null +++ b/FFT_Test/fft_old.hcc @@ -0,0 +1,274 @@ +#include <pal_master.hch>
+#include <stdlib.hch>
+#include "weights256.hch"
+#include "config.hch"
+#include "debug.hch"
+
+/* Define two multi-port RAMs for FFT calculation; one for real and one for imaginary values
+ * Extra block RAM settings are defined to make sure read and write actions can be performed
+ * within one clock-cycle.
+ * Left out extra settings on new board the clock changes TODO !!!!
+ */
+mpram
+{
+ ram signed 32 rwrite[256];
+ rom signed 32 read[256];
+} real with {block = "BlockRAM"/*, westart=2.5, welength=1, rclkpos={1.5}, wclkpos={3}, clkpulselen=0.5*/};
+
+mpram
+{
+ ram signed 32 rwrite[256];
+ rom signed 32 read[256];
+} imaginary with {block = "BlockRAM"/*, westart=2.5, welength=1, rclkpos={1.5}, wclkpos={3}, clkpulselen=0.5*/};
+
+// multiplication factors for equalizer function
+ram signed 7 eq_settings[16] = {0,2,4,7,10,13,16,19,22,26,30,35,41,48,55,63};
+
+
+/****************************************************************
+* Function: multiply *
+* *
+* Arguments *
+* x,y signed variables *
+* *
+* Description *
+* Just a multiplier. But by doing this in a function the *
+* FPGA space needed is reduced. *
+* *
+* Return Values *
+* The result after multiplication *
+****************************************************************/
+signed multiply(signed x,signed y)
+{
+ return(x*y);
+}
+
+
+/*******************************************************************
+* Function: calculate_fft *
+* *
+* Arguments *
+* select_inverse Boolean that indicates FFT or iFFT calculation *
+* *
+* Description *
+* This routine performs the Fast Fourier Transform for *
+* calculation of the frequency spectrum *
+* *
+*******************************************************************/
+void calculate_fft(unsigned 1 *select_inverse)
+{
+ unsigned 4 level;
+ unsigned 8 point1,point2,j,f,k;
+ unsigned 9 e,i;
+ signed 16 weight1,weight2;
+ signed 32 p,q,r,t;
+ signed 38 a,b;
+
+ for(level=1;level<=NUMBER_OF_COLUMNS;level++) // count all the columns
+ {
+ e=1<<(NUMBER_OF_COLUMNS-level+1); // number of points in each block in this column
+ f=(e>>1)<-8; // number of butterflies in each block in this column
+
+ for(j=1;j<=f;j++)
+ // count all the butterflies in each block
+ //par
+ {
+ // Weight factors for real (the same for FFT and iFFT)
+ weight1 = weight_re[((j-1)<<(level-1))<-7];
+
+ // Weight factors for imaginary (opposite for FFT and iFFT)
+ weight2 = (*select_inverse==0) ? -(weight_im[((j-1)<<(level-1))<-7]) : weight_im[((j-1)<<(level-1))<-7];
+
+ for(i=0@j;i<=NUMBER_OF_POINTS;i+=e) // count all the blocks in this column
+ { // Butterfly calculation
+ //par{
+ point1 = ((i<-8)-1);
+ point2 = (((i<-8)+f)-1);
+ //}
+ //par{
+
+ p = real.read[point1];
+ p += real.read[point2];
+
+ r = real.read[point1];
+ r -= real.read[point2];
+
+ q = imaginary.read[point1];
+ q += imaginary.read[point2];
+
+ t = imaginary.read[point1];
+ t -= imaginary.read[point2];
+ //}
+ a = multiply(adjs(r,38),adjs(weight1,38));
+ b = multiply(adjs(t,38),adjs(weight2,38));
+ //par{
+ real.rwrite[point2] = ((a-b)>>FRACBITS)<-32;
+ imaginary.rwrite[point1] = q;
+ //}
+ a = multiply(adjs(t,38),adjs(weight1,38));
+ b = multiply(adjs(r,38),adjs(weight2,38));
+ //par{
+ real.rwrite[point1] = p;
+ imaginary.rwrite[point2] = ((a+b)>>FRACBITS)<-32;
+ //}
+ }
+ }
+ }
+ k=0;
+ do
+ {
+ print_string("FFT[");
+ print_hex_value(adju(k,32));
+ print_string("]: ");
+ print_hex_value((unsigned)(real.read[k]));
+ print_eol();
+ k++;
+ }
+ while (k!=0);
+ // Start bit-reversing samples
+ j = 0;
+ for(i = 0;i < NUMBER_OF_POINTS;i++)
+ {
+ if(i < (0@j))
+ {
+ // point1 = j-1;
+ // point2 = (i-1)<-8;
+ //par
+ //{
+ //seq
+ //{
+ p = real.read[j];
+ real.rwrite[j] = real.read[i<-8];
+ real.rwrite[i<-8] = p;
+ //}
+ //seq
+ //{
+ q = imaginary.read[j];
+ imaginary.rwrite[j] = imaginary.read[i<-8];
+ imaginary.rwrite[i<-8] = q;
+ //}
+ //}
+ }
+
+ k = NUMBER_OF_POINTS>>1;
+
+ while((j>=k)&&(k>=2))
+ {
+ j -= k;
+ k = k>>1;
+ }
+ j += k;
+ } // Bit reversing end
+}
+
+/********************************************************************/
+
+void perform_fft(signed 16 *pcm_audio)
+{
+ unsigned 1 select_inverse;
+ unsigned 8 k;
+
+ // copy audio data to real-array before starting FFT calculation
+ // and set imaginary values to zero
+ k=0;
+ do
+ //par
+ {
+ real.rwrite[k] = (0@pcm_audio[k]);
+ imaginary.rwrite[k]=0;
+ k++;
+ } while (k!=0);
+
+ do
+ {
+ print_string("IA[");
+ print_hex_value(adju(k,32));
+ print_string("]: ");
+ print_hex_value((unsigned)(real.read[k]));
+ print_eol();
+ k++;
+ }
+ while (k!=0);
+ select_inverse=0;
+ calculate_fft(&select_inverse);
+
+ /* do
+ {
+ // print_signed_hex_value(real.read[k],32);
+ // print_eol();
+ k++;
+ }while(k!=0);*/
+}
+
+/********************************************************************/
+
+void perform_ifft(signed 16 *modified_audio/*, unsigned 6 *ifft_info*/)
+{
+ unsigned 1 select_inverse;
+ unsigned 8 k;
+ signed 32 p;
+
+ select_inverse=1;
+ calculate_fft(&select_inverse);
+
+ k=0;
+ do
+ {
+ // divide samples by number of points
+ p=(real.read[(k+95)]>>NUMBER_OF_COLUMNS);
+
+ // write data to output buffer & display buffer
+ modified_audio[k <- 6] = (p<-16);
+ //ifft_info[k] = (unsigned)(p[15:10]);
+ // print_string("MA[");
+ // print_hex_value(adju(k,16));
+ // print_string("]: ");
+ // print_hex_value((unsigned)(modified_audio[k]));
+ // print_eol();
+
+ k++;
+ } while(k[5:0] != 0);
+}
+
+/********************************************************************/
+
+void equalize_audio(unsigned 8 *fft_info)
+{
+ signed 32 p,q;
+ signed 38 a;
+ unsigned 8 i, mirror_i, old_value, m, n;
+ unsigned 8 bit;
+ unsigned 9 tmp;
+
+ macro expr equalize_bar = multiply(adjs(q,38),a)[37:6];
+
+ real.rwrite[0] = real.read[0] - 8470527; // remove DC component for calculations
+// imaginary.rwrite[0] = 0; // remove DC component
+
+ //write data to fft_info for display purposes
+ for(i=0;i<NUMBER_OF_FREQUENCIES;i++)
+ {
+ p=real.read[i];
+ q=imaginary.read[i];
+
+ if (p[31]==1) p=-p; else delay;
+ if (q[31]==1) q=-q; else delay;
+ p = (p<q) ? q : p; // This is done to get the best visual frequency result
+
+ // Logartimic display of the frequency spectrum
+ bit=248;
+ while ((p[21]==0) && (bit!=0))
+ //par
+ {
+ p = p<<1;
+ bit = bit - 31;
+ }
+ old_value = fft_info[i];
+ tmp=((0@old_value) + (0@bit))>>1;
+ fft_info[i] = (old_value<=(tmp<-8)) ? (tmp<-8) : old_value-1;
+ }
+
+ // add DC component again before IFFT calculation is performed
+ real.rwrite[0] = real.read[0] + 8470527;
+}
+
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