#include <reg52.h>

#include <intrins.h>

#define uint unsigned int

#define uchar unsigned char

sbit SPK = P3^7;

uchar FRQ = 0x00;

void Delayms(uint ms)

{

  uchar i;

while(ms--)

{

for(i=0;i<120;i++);

}

}

void main()

{

  P2 = 0x00;

TMOD = 0x11;//两个16bit定时器全开

TH0 = 0x00;

TL0 = 0xff;

IT0 = 1;

IE = 0x8b;//10001011三个中断被允许

IP = 0x01;//外部中断0优先级最高

TR0 = 0;

TR1 = 0;

while(1)

{

FRQ++;

Delayms(1);

}

}

void EX0_INT() interrupt 0

{

  TR0 = !TR0;

TR1 = !TR1;

if(P2 == 0x00)//当前状态决定了按键的作用

P2 = 0xe0;//同时亮3个

else 

P2 = 0x00;

}

void T0_INT() interrupt 1//响铃

{

  TH0 = 0xfe;

TL0 = FRQ;//随时间增加（中断加快，频率提高，声调变高），之后溢出

SPK = ~SPK;

}

void T1_INT() interrupt 3//亮灯

{

  TH0 = -45000/256;

TL0 = -45000%256;

P2 = _crol_(P2,1);

}