#includereg52.h>

sbit KEY1 = P3^1; //定義調(diào)速按鍵
sbit PWM = P1^5; //定義調(diào)速端口
unsigned char CYCLE; //定義周期T=x*0.1ms
unsigned char PWM_ON ; //定義高電平時(shí)間

void delay(unsigned int cnt)
{
while(--cnt);
}

main()
{
unsigned char PWM_Num;
TMOD |=0x01;
TH0=(65536-1000)/256;
TL0=(65536-1000)%256;
IE= 0x82;
TR0=1;

CYCLE = 10;
while(1)
{
if(!KEY1)
{
delay(10000);
if(!KEY1)
{
PWM_Num++;
if(PWM_Num==4)

PWM_Num=0;
switch(PWM_Num)

{
case 0:P0=0x06;PWM_ON=0;break;
case 1:P0=0x5B;PWM_ON=4;break;
case 2:P0=0x4F;PWM_ON=6;break;
case 3:P0=0x66;PWM_ON=8;break;
default:break;
}
}
}
}

}

void tim(void) interrupt 1 using 1
{
static unsigned char count;
TH0=(65536-1000)/256;
TL0=(65536-1000)%256;

if (count==PWM_ON)
{
PWM = 1;
}
count++;
if(count == CYCLE)
{
count=0;
if(PWM_ON!=0)
PWM = 0;

}

}