include<AT89X51.H>include<intrins.h>数码管为共阴数码管sbit s0=P27个位选通sbit s1=P26十位选通sbit s2=P25百位选通sbit s3=P24千位选通sbit dp=P07小数点sbit in=P32外部中断接CX20106的脚sbit csb=P3340KHz方波输出脚define seg P0 数码管的数据口为P1口define