C5000，汇编语言写的FIR滤波器

【实例简介】这个是低通滤波器 参数由matlab产生，DSP为C5000

【实例截图】

【核心代码】

/* 
   exp5a.c - Block FIR filter function experiment
               using input data file
*/
#define M    128       /* Input sample size */
#define L     48       /* Number of FIR filter coefficients */
#define SN     L       /* Signal buffer size */
extern unsigned int fir(int *, unsigned int, int *, unsigned int, int *, int *, unsigned int);

/* Define DSP system memory map */
#pragma DATA_SECTION(LP_h, "fir_coef");
#pragma DATA_SECTION(x, "fir_data");
#pragma DATA_SECTION(index, "fir_data");
#pragma DATA_SECTION(out, "output");
#pragma DATA_SECTION(in, "input"); 
#pragma DATA_SECTION(input, "input");
#pragma CODE_SECTION(main, "fir_code");  

/* Input data */
#include "input5.dat"

/* Low-pass FIR filter coefficients */
int LP_h[L]={
-6,28,46,27,-35,-100,-93,26,191,240,52,-291,-497,-278,
337,888,773,-210,-1486,-1895,-442,2870,6793,9445,
9445,6793,2870,-442,-1895,-1486,-210,773,888,337,
-278,-497,-291,52,240,191,26,-93,-100,-35,27,46,28,-6};

int x[SN];             /* Signal buffer */
unsigned int index;    /* Signal buffer index */
int out[M];            /* Output buffer */
int in[M];             /* Input buffer */
  
void main(void)
{
    unsigned int i,j; 

    /* Initialize filter signal buffer */
    for (i=0; i<SN;i  )
        x[i]=0;	     
    index = 0;

    /* Processing samples using a block FIR filter */    
    j=0;
    for (;;)           
    {
        for (i=0; i<M; i  )
        {
            in[i]=input[j  ];	/* Get a buffer of samples */
            if (j == 160)
                j=0;
        }
        index=fir(in,M,LP_h,L,out,x,index); /* FIR filter */ 
    }
}