/************************************************************************
File Name:	Fir_test.asm

Date Modified:	6/22/01		BM
				

Purpose:	Demonstrate initialization and operation of 
			FIR.asm on the ADSP-2192.  FIR.asm is a
			single precision direct form FIR filter.  All 
			coefficients and data values are assumed to 
			be in 1.15 format.
	
************************************************************************/

#define 	Num_Samp 		512							/* NUmber of Input samples */
#define     Taps       		31                  		/* Number of filter taps */
#define     Shift  			2                  			/* Number of shifts */
#define     Samps_per_Bin   40                  		/* Number of Input samples in each bin */
#define 	Num_Bins 		(Num_Samp/Samps_per_Bin)   	/* Number of bins */

.EXTERN fir;

/* DM data */
.section/data data1;
.VAR    IN[Num_Samp] = "input_dec.dat";	/* Input buffer */
.VAR    OUT[Num_Samp];                 	/* Output buffer */
.VAR    Delay_Line[Taps];               /* Delay line */


/* PM data */
.section/pm data2;
.VAR    COEFF[Taps] = "coeff_l.dat";

/* PM interrupt vector code */
.section/pm IVreset;
        JUMP start; NOP; NOP; NOP;      

/* Program memory code */
.section/pm program;
start:
    I0=Delay_Line;                      /* Initialize delay line pointer */
    M1 = 1;                             
    I1 = IN;							/* Initialize Input pointer */
    I2 = OUT;							/* Initialize Output pointer */
    L1=0;                               /* Initialize for modulo addressing */
    L2=0;                               /* Initialize for modulo addressing */
    M3=-1;                              
    M4=1;                               
	SE = Shift;                        	
	DMPG2=page(COEFF);

	L0=LENGTH (Delay_Line);             /* Initialize delay line circular buffer */
	ax0 = Delay_Line;                         
   	REG(b0) = ax0;                  	/* Initialize pointer to delay line */

	L4=length(COEFF);                   /* Initialize coeficient circular buffer */
    ax0 = COEFF;         
	reg(b4) = ax0;                      /* Initialize pointer to coeficient */

 	CNTR=Taps;							/* 'Taps' location delay line */	
    DO zero UNTIL CE;
zero:  dm(I0,M1)=L0;                   	/* Delay_line = 0 */


	CNTR = Num_Bins;                  	/* Num_Bins to process Num_Samp  */
    do per_bin until CE;
   		call fir (db);
 		I4=COEFF;                       /* Load Coeff buffer pointer */
    	nop;
per_bin:
		nop;

looping:   JUMP looping;                /* Loop upon itself */

/************************************************************************/