题目：
在8位数码管中，前面4位显示年份“”，接着2位是分割符“—”，最后两位是月份，从1月份开始，每隔一段时间加1个月，到12月之后又从1月份开始递增，如此往复。
#include "reg52.h"unsigned char month=1; //定义月份//共阳极数码管unsigned char code duan_code[18]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x80,0xc6,0xc0,0x86,0x8e,0xbf,0x7f};//选择锁存器void Select_HC573(unsigned char n){switch(n){case 4:P2=(P2&0x1f)|0x80;break;case 5:P2=(P2&0x1f)|0xa0;break;case 6:P2=(P2&0x1f)|0xc0;break;case 7:P2=(P2&0x1f)|0xe0;break;}}void SEG_Bit(unsigned char pos,unsigned char value){Select_HC573(6); //位选P0=0x01<<pos;Select_HC573(7); //段选P0=value;}//数码管延时函数void Delay_SEG(unsigned int t){while(t--);}//数码管静态显示void SEG_Dynamic(){SEG_Bit(0,duan_code[2]); //2Delay_SEG(500);SEG_Bit(1,duan_code[0]); //0Delay_SEG(500);SEG_Bit(2,duan_code[1]); //1Delay_SEG(500);SEG_Bit(3,duan_code[8]); //8Delay_SEG(500);SEG_Bit(4,duan_code[16]); //-Delay_SEG(500);SEG_Bit(5,duan_code[16]); //-Delay_SEG(500);SEG_Bit(6,duan_code[month/10]); //月份的十位Delay_SEG(500);SEG_Bit(7,duan_code[month%10]); //月份的个位Delay_SEG(500);}void delay(unsigned char t){while(t--){SEG_Dynamic();}}void main(){while(1){SEG_Dynamic();month++;if(month>12){month=1;}delay(100);}}
