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- ;
- ; This program originally available on the Motorola DSP bulletin board.
- ; It is provided under a DISCLAMER OF WARRANTY available from
- ; Motorola DSP Operation, 6501 Wm. Cannon Drive W., Austin, Tx., 78735.
- ;
- ; Lattice FIR Filter Macro (modified modulo count).
- ;
- ; Last Update 08 Aug 86 Version 1.0
- ;
- latfir2 macro order
- latfir2 ident 1,0
- ;
- ; LATTICE FIR
- ;
- ; Lattice FIR filter macro
- ;
- ; Input value in register B, output value in register B.
- ;
- ; Macro call: latfir2 order
- ; order - order of filter (number of K coefficients)
- ;
- ; Alters Data ALU Registers:
- ; x0 y0 y1 a b
- ;
- ; Alters Address Registers:
- ; r0 r4
- ;
- ; Alters Program Control Registers:
- ; pc sr
- ;
- ; Uses 2 locations on stack
- ;
- move b,x:(r0)+ y:(r4)+,y0 ;sv B as fst st., mv fst k
- do #order,_endlat
- move x:(r0),a b,y1 ;get state, set t for mul by k
- macr y1,y0,a a,x0 ;t*k+s, copy s
- macr x0,y0,b a,x:(r0)+ y:(r4)+,y0 ;s*k+t, sv st., nxt k
- _endlat
- move x:(r0)-,x0 y:(r4)-,y0 ;adjust pointers
- endm
-