#include
#define?uchar?unsigned?char
#define?uint?unsigned?int
void?isr_t0（void）;????//定時器T0中斷，
sbit?SINGAL1=P2^0;?????????//兩路PWM信號輸出端口，
sbit?SINGAL2=P2^1;
sbit?P1_0=P1^0;???????//P1端口做為調節信號輸入口，
sbit?P1_1=P1^1;
sbit?P1_2=P1^2;
sbit?P1_3=P1^3;

int?a=100;
int?b;
uchar?c=5;
uint?PWM1;

void?isr_t0（void）?interrupt?1?????//定時器實現T0方波輸出
{?????int?khmn;??
??????TH0=0xFF;?????????????????//定時初值0.1ms
??????TL0=0x9B;
	??PWM1++;?
	??b=a/5*c;
????if?（PWM1<=b）????????????????//a=10初始頻率為50Hz，
	????{?SINGAL1=0;
		??SINGAL2=1;}
????else?if?（（PWM1>b）&&（PWM1<2*a））
	??????{SINGAL1=1;
		???SINGAL2=0;}
????else?if（PWM1=2*a）
	?????????{PWM1=0;}	
??if?（P1_0==0）
	??{k=20000;
	???while?（k--）;
	???