Mic92/fft
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Inneren Schleifenheader und Scaling als TIE Instruktionen implementiert

Browse Source
This commit is contained in:
unknown 2015-03-04 18:52:18 +01:00
parent 0c0c708e70
commit f8cfb71c62
2 changed files with 39 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
fft.c
View File

@ -61,6 +61,7 @@ int fix_fft(fixed fr[], fixed fi[], int m, int inverse)
scale = 0;
int mm = m;
xtbool t;
/* decimation in time - re-order data */
for(m=1; m<=nn; ++m) {
@ -87,19 +88,14 @@ int fix_fft(fixed fr[], fixed fi[], int m, int inverse)
shift = 0;
for(i=0; i<n; ++i)
{
j = fr[i];
if(j < 0) j = -j;
m = fi[i];
if(m < 0) m = -m;
if(j > 16383 || m > 16383)
{
shift = 1;
break;
}
xtbool sshift;
FFT_scale(fr[i], fi[i], sshift, scale);
if(sshift)
{
shift = (int) sshift;
break;
}
}
if(shift) ++scale;
}
else
{
@ -122,9 +118,14 @@ int fix_fft(fixed fr[], fixed fi[], int m, int inverse)
FFT_reg reg;
fixed *reg_s = ((fixed*) &reg);
for(i=m; i<n; i+=istep)
WUR_FFT_loop(m);
while(1)
{
j = i + l;
i = RUR_FFT_loop();
FFT_loop_check(n, istep, t, j);
if(!t)
break;
reg_s[3] = fr[i];
reg_s[2] = fr[j];

24
fft_inst.tie
View File

@ -132,6 +132,30 @@ table SIN_wave 16 1024 {
regfile FFT_reg 64 2 fftv
state FFT_loop 32 add_read_write
operation FFT_scale {in AR fr, in AR fi, out BR shift, inout AR scale} {}
{
wire [4:0] jc1 = TIEcmp(fr[15:0], 16'd16383, 1'b1);
wire [4:0] mc1 = TIEcmp(fi[15:0], 16'd16383, 1'b1);
wire [4:0] jc2 = TIEcmp(fr[15:0], 16'd49153, 1'b1);
wire [4:0] mc2 = TIEcmp(fi[15:0], 16'd49153, 1'b1);
wire x = jc1[0] | mc1[0] | jc2[4] | mc2[4];
assign shift = x;
wire [15:0] scaleInc = TIEadd(scale, 16'b0, 1'b1);
assign scale = TIEmux(x, scale, scaleInc);
}
operation FFT_loop_check {in AR n, in AR istep, out BR t, out AR j} {inout FFT_loop}
{
wire [4:0] cmpres = TIEcmp(FFT_loop, n, 1'b0);
assign t = cmpres[4];
assign FFT_loop = TIEadd(FFT_loop, istep, 1'b0);
assign j = TIEadd(FFT_loop, {1'b0, istep[15:1]}, 1'b0);
}
operation FFT_bit_reverse {in AR b, out AR o, in AR m} {}
{
assign o = {