section 7 - Index of

; first group in the last passmove x:(rO)+,A y:(r4)+,Bsub B,A x:(rO)+,xO y:(r6)+,yOaddl A,B A,x:(r1) y:(r4),Asub xO,A B,x:(r7)move y:(r4)+,Badd xO,B A,y:(r1)move x:(rO)+,A B,y:(r7);A=a, B=c;A=a-c=c',xO=b, yO=Wr for next bfly;B=a+C=a', A=d,PUT c' to x:b;A=d-b=d',PUT a' to x;B=d;B=d+b=b', A=next a,PUT d';A=next a, PUT b'movedox:(r2)+,xO y:(r4)+,Bn2,endJastg;xO=Wi,B=next c;rest groups in the last passIntermediate Passes -- W(n) < 1A---\ /---A'= Re[ A + jC + (B - jO)W(k)] = A+BWr+OWi=A+ T1B----\-'-'----B'= Im[ A + jC - (B - jO)W(k)] = C+OWr-BWi= T2+CC----/I \----C'= Re[ A + jC - (B - jO)W(k)] = A-(BWr+OWi)=A-T10---/ \---0'= Im[-A - jC - (B - jO)W(k) ] = -C+OWr-BWi= T2-Cmove x:(rO)+,x1 y:(r4)-,y1mpy x1 ,yO,B x:(r3)+,r7mac xO,y1,B x:(r3)+,r1sub B,Aaddl A,B A,x:(r1)mpy y1 ,yO,A B,x:(r7)mac -x1,xO,A y:(r4)+n4,Bsub B,A x:(r2)+,xO y:(r6)+,yOaddl A,B A,y:(r1)move x:(rO)+,A B,y:(r7)move y:(r4)+,B;x1 =b, y1 =d, r4 ptr back to c;A=bWr,;B=bWr +dWi= T1 , get first index;A=a-T1=c', get second index;B=a+ T1 =a', PUT c' to x:b;B=dWr, B=c PUT a';A=dWi-bWr= T2, B=c, r4 ptr to next c;A= T2-c=d',xO=next Wi, yO=next Wr;B= T2+c=b', update r4, A=next a, PUT d';PUT b', A=next a;B=nextcendm; Real input FFT based on Glenn Bergland algorithm; Normal order input and normal order output.; Since 56001 does not support Bergland addressing, extra instruction cycles are needed; for converting Bergland order to normal order.lt has been done in the last pass by; looking at the bergtable.; 'bergsincos' generates sin and cos table with size of points/4,COS in Y, SIN in X; 'bergorder' generates table for address conversion, the size of twiddle factors is half; of FFT output's; 'rfft-56b' does FFT.; Normal order input and normal order output.Figure 8-5 Real Input FFT Based on Glenn Bergland Algorithm (Sheet 7 of 8)