关于动态数码管，为什么只亮一半的？代码如下#include<

关于动态数码管，为什么只亮一半的？
代码如下
#include<reg52.h>typedef unsigned char u8;typedef unsigned int u16;sbit LCA=P2^2;sbit LCB=P2^3;sbit LCC=P2^4;u8 code mima[16]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
void delay(u16 i){while(i--);}
void global(){u8 i;
for(i=0;i<8;i++){
switch(i){
case 0:LCA=0;LCB=0;LCB=0;break;
case 1:LCA=1;LCB=0;LCB=0;break;
case 2:LCA=0;LCB=1;LCB=0;break;
case 3:LCA=1;LCB=1;LCB=0;break;
case 4:LCA=0;LCB=0;LCB=1;break;
case 5:LCA=1;LCB=0;LCB=1;break;
case 6:LCA=0;LCB=1;LCB=1;break;
case 7:LCA=1;LCB=1;LCB=1;break;default :break;}
P0=mima[i];
delay(50000);
P0=0x00;}}
void main(){
while(1)
{global(); }
}