Generate sine wave program using PWM

/*******************************************************************
     Experiment name: Generate sine wave demonstration experiment
    device: ATmega16L
   crystal oscillator: external 12M
     wiring method:
        1. PD5 connects to low-pass filter input
     2. Use oscilloscope to measure its output waveform
******************************************************************/
#include
#include
#include
#pragma interrupt_handler timer1:9
char auc_SinParam[128]={//128-point sine wave sample value
128,134,140,147,153,159,165,171,177,182,188,193,198,204,208,213,
218,222,226,230,233,237,240,242,245,247,249,251,252,253,254,254,
254,254,253,252,251,250,248,246,244,241,238,235,232,228,2 24,220,
215,211,206,201,196,191,185,179,174,168,162,156,150,144,137,131,
125,119,112,106,100,94,88,82,77,71,65,60,55,50,45,41,
36,32,28,24,21,18,15,12,10,8,6,5,4,3,2,2,
2,2,3,4,5,7,9,11,14,16,19,23,26,30,34,38,
43,48,52,57,63,68,74,79,85,91,97,103,109,116,122,128 
};
char x=0;
//T/C1 overflow interrupt service
void timer1(void)
{
       x=x+1;
       if (x>128)
       x=0;
      OCR1A=auc_SinParam[x];//auc_SinParam[x];//Sampling point pointer to compare match register
}
void main(void)
{
      DDRD=0xff;//PB3 output mode, as OC0 output PWM wave
      TIMSK=0x04; //Interrupt mask bit, no interrupt is enabled
      TIFR=0; //Interrupt flag
      TCCR1A=0xA1; //Open PWM
      TCCR1B=0x09;//System clock
      SREG=0x80; //Open global interrupt
      OCR1A=128;//auc_SinParam[x];
}