#include <reg51.h>
#include"intrins.h"
sbit fan=P3^7;
sbit pressed=P3^5;

unsigned char fan_open=0;
unsigned char int_time=0;
unsigned char table[9]={20,30,40,50,60,70,80,90,100};
unsigned char p=0;

//中斷子程序
void ext0(void) interrupt 0
{
int_time++;
fan_open--;
if(fan_open==0)	  {fan_open=table[p];fan=0;}
if(int_time>=100)  {fan_open=table[p];int_time=0;fan=1;}
} 

//延時(shí)子程序
void delay(void)
{
unsigned int i,j;
for(i=0;i<10000;i++)
	for(j=0;j<4;j++)
		_nop_();
}

/************主  程序*************/
void main(void)
{ 
fan_open=table[p];
IT0=1;
EA=1;
EX0=1;
fan=1;
while(1)
{
if(pressed==0)	{if(p>=9) p=0;p++;}	
delay();  	
}
}