IIR filter in 56300

Hi, Can you tel me, is this code can represents IIR filter in 56300
procesor?

MOVE #STATES,R0
MOVE #COEF,R4
MOVE #N-1,M0
MOVE #2*N, M4
MOVE #OUT,R1

DO FOREVER , END

MOVE X:(R0)+,X0 Y:(R4)+,Y0

REP #N-1
MAC -X0,Y0,A X:(R0)+,X0 Y:(R4)+,Y0
MACR -X0,Y0,A X:(R0)+,X0 Y:(R4)+,Y0

CLR A A,Y1

REP #N-1
MAC +X0,Y0,A X:(R0)+,X0 Y:(R4)+,Y0
MAC +X0,Y0,A X(R0)-,X0 Y:(R4)+,Y0

MACR +Y1,Y0,A Y1,X:(R0)
MOVE A1,X:(R1)+

END


Thank You for help,
Best Regards
Bartosz Rzemek

On Feb 8, 5:41 pm, "i...@nazwisko.com" <bartosz.rze...@gmail.com>
wrote:
> Hi, Can you tel me, is this code can represents IIR filter in 56300
> procesor?
>
> MOVE #STATES,R0
> MOVE #COEF,R4
> MOVE #N-1,M0
> MOVE #2*N, M4
> MOVE #OUT,R1
>
> DO FOREVER , END
>
> MOVE X:(R0)+,X0 Y:(R4)+,Y0
>
> REP #N-1
> MAC -X0,Y0,A X:(R0)+,X0 Y:(R4)+,Y0
> MACR -X0,Y0,A X:(R0)+,X0 Y:(R4)+,Y0
>
> CLR A A,Y1
>
> REP #N-1
> MAC +X0,Y0,A X:(R0)+,X0 Y:(R4)+,Y0
> MAC +X0,Y0,A X(R0)-,X0 Y:(R4)+,Y0
>
> MACR +Y1,Y0,A Y1,X:(R0)
> MOVE A1,X:(R1)+
>
> END

it approximates working code (i think it's a Direct Form 2), but will
not work for a few reasons i can identify.

you have to indent the executable lines if they aren't to be mistaken
as labels.  "END" is not a good choice for a label as it is an
assembler directive.

you need to reset your state pointer, R0, before doing the feedforward
signal paths (oh, maybe you don't since you have modulo arithmetic on
that pointer).  and you're not inputing any signal at the beginning.
that first MAC instruction, what is the value of accumlator A before
it is executed (i think it should be your input).

what platform are you running this on and what is your application?
if it is audio, i don't think the Direct Form 2 is your best choice,
particularly for a fixed-point DSP as the 56K is.

r b-j