代码如下：

#include"reg51.h"

#define uchar unsigned char

sbit ksaw=P2^0; //锯齿波按键.

sbit ktran=P2^1; //三角波按键.

sbit ksquare=P2^2; //方波按键.

sbit ksin=P2^3; //正弦波按键.本文引用地址：http://www.eepw.com.cn/article/201611/315465.htm

uchar key1;

uchar keya;

uchar keyb;

uchar keyc;

uchar keyd;void delay( );

uchar code tab[128]={

64,67,70,73,76,79,82,85,88,91,94,96,99,102,104,106,

109,111,113,115,117,118,120,121,123,124,125,126,126,

127,127,127,127,127,127,127,126,126,125,124,123,121,

120,118,117,115,113,111,109,106,104,102,99,96,94,91,

88,85,82,79,76,73,70,67,64,60,57,54,51,48,45,42,39,

36,33,31,28,25,23,21,18,16,14,12,10,9,7,6,4,3,2,1,

1,0,0,0,0,0,0,0,1,1,2,3,4,6,7,9,10,12,14,16,18,21,23,

25,28,31,33,36,39,42,45,48,51,54,57,60};

void delay( )

{

uchar i;

for(i=0;i<255;i++);

}

void saw(void) //锯齿波.

{

uchar i;

while(1)

{

if(keya==1)

{

for(i=0;i<255;i++)

P0=i;

}

else break;

}

}

void tran(void) //三角波

{

uchar i;

while(1)

{

if(keyb==1)

{

for(i=0;i<255;i++)

P0=i;

for(i=255;i>0;i--)

P0=i;

}

else break;

}

}

void square(void) //方波

{

while(1)

{

if(keyc==1)

{

P0=0x00;

delay();

P0=0xff;

delay();

}

else break;

}

}

void sin( ) //正弦波

{

unsigned int i=0;

while(1)

{

if(keyd==1)

{

if(++i==128)i=0;

{P0=tab[i];}

}

else break;

}

}

void main(void) //主函数

{

EA=1;

EX0=1;

while(1)

{

if(key1)

{

switch(key1)

{

case 0x01:

//P0=0XC0;//

saw();

break;

case 0x02:

//P0=0XC0;//

tran();

break;

case 0x03:

//P0=0XBE;//

square();

break;

case 0x04:

//P0=0XB6;//

sin();

break;

}

}

}

}

void int0(void)interrupt0 using 1

{

if(ksaw==0)

{key1=0x01;keya=1;keyb=0;keyc=0;keyd=0;}

if(ktran==0)

{key1=0x02;keya=0;keyb=1;keyc=0;keyd=0;}

if(ksquare==0)

{ key1=0x03;keya=0;keyb=0;keyc=1;keyd=0;}

if(ksin==0)

{key1=0x04;keya=0;keyb=0;keyc=0;keyd=1;}

}

图片如下：