# include ' reg 52.h ' typedefunsignedcharu 8; typedef unsigned int u16; sbit led=P2^0; sbit k4=P3^3; //外部中断1voiddelay(U16I ) {while(I-- ); } void中段() {EA=1; //总中断EX1=1; //外部中断1接通IT1=1; //外部中断1低电平触发(}void main ) {中端}; //调用中断函数while(1) }voidzhong(interrupt2//外部中断服务函数) Delay ) 1000; //消除按键抖动if (k4==0) ) {led=~led; //led默认为高电平,在此实现状态反转}