programming Echo audio effect on DSK6455 : problem implementing delay line, processor not fast enough?

Good morning,

I am currently trying to implement simple audio effects such as echo reverberation...  When i run my program the audio output is really dirty.  I am not sure why my code doesnt work.

My code :

#include "dsk6455.h"

#include "dsk6455_aic23.h"

/* Codec configuration settings */

DSK6455_AIC23_Config config = {

    0x0117, // 0 DSK6455_AIC23_LEFTINVOL  Left line input channel volume

    0x0017, // 1 DSK6455_AIC23_RIGHTINVOL Right line input channel volume

    0x00d8, // 2 DSK6455_AIC23_LEFTHPVOL  Left channel headphone volume

    0x00d8, // 3 DSK6455_AIC23_RIGHTHPVOL Right channel headphone volume

    0x0011, // 4 DSK6455_AIC23_ANAPATH    Analog audio path control

    0x0001, // 5 DSK6455_AIC23_DIGPATH    Digital audio path control

    0x0000, // 6 DSK6455_AIC23_POWERDOWN  Power down control

    0x0043, // 7 DSK6455_AIC23_DIGIF      Digital audio interface format

    0x0081, // 8 DSK6455_AIC23_SAMPLERATE Sample rate control

    0x0001 // 9 DSK6455_AIC23_DIGACT     Digital interface activation

};

void main()

{

    DSK6455_AIC23_CodecHandle hCodec;

    Uint32 leftsample,x[2201],  y=0;

    Int16 i;

                // initailize x with zeros

                for(i=0;i<22000;i++)

                               x[i] =0

    // initializes the board

    DSK6455_init();

     DSK6455_DIP_init();

    /* Start the codec */

    hCodec = DSK6455_AIC23_openCodec(0, &config);

    DSK6455_AIC23_setFreq(hCodec,DSK6455_AIC23_FREQ_44KHZ);  //set sampling frequency to 44Khz

                while(1)

                {

            /* read a sample from the left channel */

            while (!DSK6455_AIC23_read32(hCodec, &leftsample));

                    // 0.5s delay line

                      for(i=0;i<22000;i++)

                               x[i] = x[i-1];

                               x[0] = leftsample+y;

                    y = leftsample + x[22000] /2 ;

                    leftsample = y;

                /* Send a sample to the left channel */

                while (!DSK6455_AIC23_write32(hCodec,  2*leftsample));

            }

    /* Close the codec */

    DSK6455_AIC23_closeCodec(hCodec);

}

For exemple when i replace the part in red with

                    for(i=0;i<5;i++)

                               x[i] = x[i-1];

                               x[0] = leftsample+y;

                    y = leftsample + x[5] /2 ;

                    leftsample = y;

   i can hear the sound of music input with good quality. The more i increases the worst the audio output gets. So I thought that the DSP doesnt process fast enougth betweem to samples. The TMS320C6455 is 1Ghz fast. If this is the problem, how can I implement delay lines?

Thank you for your help

Regards

Samuel