急求:单片机上电时数码管显示“0”,编写C51语言程序 利用单片机的外部中 ...答:include<reg51.h> define uchar unsigned char;uchar distab[]= {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x00};uchar flag;sbit key=P3^2;void ext0() interrupt 0 { flag=1;} main(){ IT0=1;EA=1;EX0=1;P1=distab[0];...