PWM输出频率问题

只看该作者 · 2007-1-8 10:22

我想要改变这个程序的PWM输出频率。
可是我怎么改定时器的值，输出的频率都是在2kHZ不变。请高手指教。应用的芯片是P89LPC901.
Uchar code sintab[160]= {
0xFF,0xEB,0xFF,0xFA,0xFF,0xE6,0xFF,0xF0,0xFF,0xE1,0xFF,0xE6,0xFF,0xDC,0xFF,0xDC,0xFF,0xD7,0xFF,0xD2,
0xFF,0xD2,0xFF,0xC8,0xFF,0xCD,0xFF,0xBE,0xFF,0xC8,0xFF,0xB4,0xFF,0xC3,0xFF,0xAA,0xFF,0xBE,0xFF,0xA0,
0xFF,0xB4,0xFF,0xAA,0xFF,0xBE,0xFF,0xB4,0xFF,0xC3,0xFF,0xBE,0xFF,0xC8,0xFF,0xC8,0xFF,0xCD,0xFF,0xD2,
0xFF,0xD2,0xFF,0xDC,0xFF,0xD7,0xFF,0xE6,0xFF,0xDC,0xFF,0xF0,0xFF,0xE1,0xFF,0xFA,0xFF,0xE6,0xFF,0xEB,
0xFF,0xEB,0xFF,0xE6,0xFF,0xFA,0xFF,0xE1,0xFF,0xF0,0xFF,0xDC,0xFF,0xE6,0xFF,0xD7,0xFF,0xDC,0xFF,0xD2,
0xFF,0xD2,0xFF,0xCD,0xFF,0xC8,0xFF,0xC8,0xFF,0xBE,0xFF,0xC3,0xFF,0xB4,0xFF,0xBE,0xFF,0xAA,0xFF,0xB4,
0xFF,0xA0,0xFF,0xBE,0xFF,0xAA,0xFF,0xC3,0xFF,0xB4,0xFF,0xC8,0xFF,0xBE,0xFF,0xCD,0xFF,0xC8,0xFF,0xD2,
0xFF,0xD2,0xFF,0xD7,0xFF,0xDC,0xFF,0xDC,0xFF,0xE6,0xFF,0xE1,0xFF,0xF0,0xFF,0xE6,0xFF,0xFA,0xFF,0xEB,
} ;

sbit OUT=P0^4;

main()
{
P0M1&=0xef;
P0M2|=0x10;
TMOD=0x11;
EA=1;
ET1=1;
ET0=1;
TR0=1;
TR1=0;
while(1);
}

Timer0() interrupt 1
{
TR0=0;
OUT=1;
TR1=1;
}

Timer1() interrupt 3
{
Uchar aa,bb;
OUT=0;
aa=bb*4;
TR1=0;
TH0=sintab[aa];
TL0=sintab[aa+1];
TH1=sintab[aa+2];
TL1=sintab[aa+3];
bb++;
if(bb>39)
{
bb=0;
}
TR0=1;
}