C51单片机中怎么写一个中断程序，可以用一个温度传感器来实现。当温度过高时就自动报警。

#include <reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit DS=P3^7; //define interface 定义DS18B20接口
uint temp; // variable of temperature
uchar flag1; // sign of the result positive or negative
sbit p0_5=P0^5;
sbit p2_7=P2^7;
sbit p2_4=P2^4;
sbit p2_5=P2^5;
sbit p2_6=P2^6;

unsigned char code TABLE[]={
0xd7,0x11,0xcd,0x5d,0x1b,
0x5e,0xde,0x15,0xdf,0x5f,
0x9f,0xdf,0xc6,0xd7,0xce,0x8e};
void delay(uint count) //delay
{
uint i;
while(count)
{
i=200;
while(i>0)
i--;
count--;
}
}
void Init_Com(void)
{
TMOD = 0x20;
PCON = 0x00;
SCON = 0x50;
TH1 = 0xFd;
TL1 = 0xFd;
TR1 = 1;
}
void dsreset(void) //send reset and initialization command
{
uint i; //DS18B20初始化
DS=0;
i=103;
while(i>0)i--;
DS=1;
i=4;
while(i>0)i--;