/*1 */ // FIR_c.c  FIR filter. Include file of N order FIR filter coefficients 
/*2 */ #include "DSK6713_aic23.h"
/*3 */ #include "LPF1500.cof"              // coefficient file LPF @ 1500Hz
/*4 */ int yn = 0;                         // initialize filter's output
/*5 */ short x[N+1];                       // input samples (N+1 samples)
/*6 */ Uint32 fs=DSK6713_AIC23_FREQ_8KHZ;  // sampling frequency of codec
/*7 */ 
/*8 */ interrupt void c_int11()            // ISR
/*9 */ {
/*10*/         short k;
/*11*/    
/*12*/         x[0] = input_left_sample(); // new input @ beginning of buffer
/*13*/         yn = 0;                     // initialize filter's output
/*14*/         
/*15*/         for (k = 0; k<= N; k++)
/*16*/            yn += (h[k] * x[k]);     // y(n) += h(k)* x(n-k)
/*17*/            
/*18*/         for (k = N; k > 0; k--)     // starting @ end of buffer
/*19*/            x[k] = x[k-1];           // update delays with data move
/*20*/ 
/*21*/         output_left_sample((short)(yn >> 15));// scale output filter
/*22*/         return;                     
/*23*/ }
/*24*/ 
/*25*/ void main()
/*26*/ {
/*27*/         comm_intr();                // init DSK, codec, McBSP
/*28*/         while(1);                   // infinite loop
/*29*/ }