#include

sbit key =P1^1;

sbit led1=P1^2;

sbit led2=P1^3;

sbit led3=P1^4;

bit key_flag;

bit flag_500ms;

void InitTimer0(void)

{

TMOD |= 0x01;

TH0 = 0x3C;

TL0 = 0x0B0;

EA = 1;

ET0 = 1;

TR0 = 1;

}

unsigned char stat;

void main(void)

{

InitTimer0();

key_flag=0;

stat=0;

while (1)

{

if (key_flag) stat++;

stat%=3;

switch (stat)

{

case 0:

led3=led2=1;

led1=flag_500ms;

break;

case 1:

led1=led3=1;

led2=flag_500ms;

break;

case 2:

led1=led2=1;

led3=flag_500ms;

break;

default :break;

}

}

}

unsigned char key_time,time_500;

void Timer0Interrupt(void) interrupt 1 //50ms

{

TH0 = 0x3C;

TL0 = 0x0B0;

//add your code here!

key=1;

if (!key) key_time++;

else key_time=0;

if (key_time>5)

{

key_time=5;

}

if (key_time==4)key_flag=1;

if (time_500)time_500--;

else

{flag_500ms=1;time_500=10;}

}