产生几种不同的波形

要求：利用DA转化产生几种不同的波形，例如三角波，锯齿波等等

#include

#define uchar unsigned char

#define uint unsigned int

#define juchi 0

#define fangbo 1

#define sanjiao 2

#define zhengxian 3

uchar xdata DA_CS _at_ 0xA000;

uint i;

uchar tag;

void delay(int ms)

{

int i,j;

for(i = 0;i < 50;i++)

for(j = 0;j < 60;j++)

{

;

}

}

void time0() interrupt 1

{

TH0=(65535-10000)/256;

TL0=(65535-10000)%256;

switch(tag){

case juchi:

//锯齿

i++;

DA_CS=i;

break;

case fangbo:

i+=85;

if(i==255){

i=0;

}

DA_CS=i;

break;

case sanjiao:

for(i=0;i<254;i++){

DA_CS=i;

// if(i = 0x80) delay(30);

delay(1);

}

for(i=255;i>1;i--){

DA_CS=i;

// if(i = 0x80) delay(30);

delay(1);

}

break;

case zhengxian:

break;

}

}

void main()

{

TMOD=0x01;

TR0=1;

IE=0x82;

TH0=(65535-10000)/256;

TL0=(65535-10000)%256;

i=0;

tag=sanjiao;

while(1);

}