; ; This program originally available on the Motorola DSP bulletin board. ; It is provided under a DISCLAIMER OF WARRANTY available from ; Motorola DSP Operation, 6501 Wm. Cannon Drive W., Austin, Tx., 78735. ; ; Last Update 15 Jul 87 Version 1.0 ; iir7 macro nsec iir7 ident 1,0 ; ; Implements cascaded biquads ; ori #$08,mr ;set scaling mode move x:(r0)+,x0 y:(r4)+,y0 ;first state, a12 do #nsec,_ends ;do each section mac -x0,y0,a x:(r0)-,x1 y:(r4)+,y0 ;ax2 macr -x1,y0,a x1,x:(r0)+ y:(r4)+,y0 ;ax1 mac x0,y0,a a,x:(r0)+ y:(r4)+,y0 ;bx2 mac x1,y0,a x:(r0)+,x0 y:(r4)+,y0 ;bx1 _ends rnd a ;round result andi #$f7,mr ;remove scaling mode endm