#include <stdio.h>
#define ORDER 6
#define N_TYPE 4

float uan[ORDER];

const float am[N_TYPE][ORDER] =
    {{ 4.1192222308E+00, -7.9461239440E+00,  8.8783717620E+00,
      -6.0217835144E+00,  2.3394595546E+00, -4.0893882993E-01},
     { 2.8926648468E+00, -4.4359438709E+00,  3.8883448827E+00,
      -2.2117294769E+00,  7.2001335496E-01, -1.5465692383E-01},
     { 3.5888336860E+00, -6.1889446395E+00,  6.5416338267E+00,
      -4.4882980453E+00,  1.8702361764E+00, -3.7994438305E-01},
     { 3.4281234344E+00, -5.5413916526E+00,  5.3792232701E+00,
      -3.2646085703E+00,  1.1097043528E+00, -1.5772714318E-01}};

const float bm[N_TYPE][ORDER+1] =
    {{ 2.0997096708E-02, -3.7296829396E-02,  6.5179345746E-02, -6.0192456239E-02,
       6.5179345746E-02, -3.7296829396E-02,  2.0997096708E-02},
     { 2.8372284397E-01, -1.4556129719E+00,  3.3288547189E+00, -4.3109161099E+00,
       3.3288547189E+00, -1.4556129719E+00,  2.8372284397E-01},
     { 4.7108438268E-02, -5.4379658554E-02, -2.8654478123E-02, -2.0920349128E-17,
       2.8654478123E-02,  5.4379658554E-02, -4.7108438268E-02},
     { 4.5973608329E-01, -2.0865614291E+00,  4.5221275998E+00, -5.7439281990E+00,
       4.5221275998E+00, -2.0865614291E+00,  4.5973608329E-01}};

void main()
{
    short yn;
    int m, type;
    float y, utmp;
    volatile int pos;                   /* position of slider    */
   
    InitDSK(cach_bk4);                  /* Initialize DSK        */

    for (m=0; m<ORDER; m++) uan[m] = 0.0;
    pos = 0;

    while(1)                            /* Endless loop          */
    {
        utmp = (float)McBSP0ReadRdy();  /* input                 */

        if (pos != 0)                   /* LPF, HPF, BPF, or BRF */
        {
            type = pos - 1;
            for (m=0; m<ORDER; m++) utmp = utmp + am[type][m]*uan[m];
            y = bm[type][0]*utmp;
            for (m=0; m<ORDER; m++) y = y + bm[type][m+1]*uan[m];
            yn = (short)y & 0xFFFE; 
            for (m=ORDER-1; m>0; m--) uan[m] = uan[m-1];
            uan[0] = utmp;
        }
        else                            /* No filter             */
            yn = (short)utmp & 0xFFFE;
        McBSP0Write(yn);                /* output                */
    }
}

u/n은 안되다고 나와서 uan 으로 바꿈.ㅠ
InitDSK(cach_bk4); 요건 지우고
input 이랑 output 를 바꿔서 출력하라는데 어떻게 바꿔야 할지 모르겠어요. ㅠㅠ
교수님은 잘 바꾸면 된다고하고. 교실엔 2시간동안 되는사 람이 없고.
하나만 알면 나머지도 다 잘 될것 같은데 ..ㅠㅠ 도와주실 분..ㅠㅠ