AT89C51SND1C Programmieren Interruptproblem

#include <stdio.h>

#include <at8xc51snd1.h>

code unsigned char *Adresse;

extern void initlcd (void);

extern void loeschenlcd (void);

extern void textlcd (unsigned char *text, unsigned char zeile);

void InitMP3();

void InitAudio();

void InitPLL();

void MP_ISR(void) interrupt 5;

unsigned char zeile1[16];

unsigned char zeile2[16];

void main (void)

{

  initlcd();

  loeschenlcd();

  Adresse=0x2000;

  InitMP3();

  InitAudio();

  InitPLL();

  P5_3=1;

  //Interrupt & MP3 Interrupt ein

  EA = 1;

  EMP3 = 1;

  //Bit MSKREQ löschen

  MP3CON = 0b10011000;

  AUDCON1 = AUDCON1&&0b00000001;

  IPH0 = IPH0&&0b00100000;

  IPL0 = IPL0&&0b00100000;

  while(1)  

  {

    sprintf(zeile1, "NO Interrupt");

    textlcd (zeile1,1);

  }

}

void InitMP3()

{

  MP3CLK=3;

  MP3VOL = MP3VOR = 0x0F;

  //MP3CON=0xA0;

}

void InitAudio()

{

  AUDCLK=7;

  AUDCON0=0x86;

  AUDCON1=0x41;

}

void InitPLL()

{

  PLLNDIV=125;

  PLLRDIV=0x8E;

  PLLCON=0b00000010;

}

void MP3_Decoder_ISR(void) interrupt 5

{

  sprintf(zeile2, "Interrupt OK");

  textlcd (zeile2,2);

  if(MP3STA1&&0b00001000)

  {

    MP3DAT = *Adresse;

    Adresse++;

  }

}