The nesting of timer 0 and external interrupt 0 realizes the running light and button respectively

#include <STC12C5A60S2.h>

typedef unsigned char u8;

typedef enum

{

Tim0_L_Int0_H = 1,

Tim0_L_Int0_L,

Tim0_H_Int0_L,

}EnumCase;

sbit LED1 = P2 ^ 4;

sbit LED2 = P2 ^ 5;

sbit LED3 = P2 ^ 6;

sbit LED4 = P2 ^ 7;

sbit BEEP = P1 ^ 0;     

sbit KEY1 = P3 ^ 2;

sbit KEY2 = P3 ^ 4;

//---------------------------------------------------------------------

static u8 i_1sCnt = 0;

static u8 LEDStatus = 0;

//---------------------------------------------------------------------

void delay_2ms(unsigned long int time) //2ms�Ļ�

{

unsigned long int i;

for (i = 0; i < time * 100; i++);

}

void SetPriorty(EnumCase chose)

{

switch (chose)

{

case Tim0_L_Int0_H:

IP = 0x01;

break;

case Tim0_L_Int0_L:

IP = 0x00;

break;

case Tim0_H_Int0_L:

IP = 0x02;

break;

default:

break;

}

}

void Timer0_Init()

{

TH0 = 0; // Maximum delay, about 130ms

TL0 = 0;

TMOD = 0x01;     

TR0 = 1;

ET0 = 1;

  EA = 1;

}

void Timer0() interrupt 1

{

TH0 = 0;  

TL0 = 0;

i_1sCnt++;

if (i_1sCnt==15)

{

i_1sCnt = 0;

LEDStatus++;

switch (LEDStatus)

{

case 1:

LED1 = 0; LED2 = 1; LED3 = 1; LED4 = 1;

break;

case 2:

LED1 = 1; LED2 = 0; LED3 = 1; LED4 = 1;

break;

case 3:

LED1 = 1; LED2 = 1; LED3 = 0; LED4 = 1;

break;

case 4:

LED1 = 1; LED2 = 1; LED3 = 1; LED4 = 0;

LEDStatus = 0;

break;

default:

break;

}

}

}

void ISR_Init()

{

IT0 = 0;   

EX0 = 1;   

  EA = 1;    

}

void INT0_ISR() interrupt 0

{

EX0 = 0;  

BEEP = 1;

delay_2ms(125);

BEEP = 0;

delay_2ms(125);

BEEP = 1;

delay_2ms(125);

BEEP = 0;

delay_2ms(125);

EX0 = 1; 

}

//-------------------------------------------------------------------------

//Set the ones you want to view to 1, and the ones you don't want to view to 0. Only one is 1

#define TEST1  1

#define TEST2  0

#define TEST3  0

void main()

{

BEEP = 0;

#if TEST1

SetPriorty(Tim0_L_Int0_H);

#endif

#if TEST2

SetPriorty(Tim0_L_Int0_L);

#endif

#if TEST3

SetPriorty(Tim0_H_Int0_L);

#endif

Timer0_Init(); //

ISR_Init();

while (1);

}