关于数码管动态显示，为什么不能跑完接龙，到第二下就停住了

#include <reg52.h>
void delay(unsigned int t)
{
    while(t--)
    {
        unsigned char j;
        for(j=0;j<125;j++);
    }
}
/*unsigned char code b[]={
 
                0x3F,  //"0"
                0x06,  //"1"
                0x5B,  //"2"
                0x4F,  //"3"
                0x66,  //"4"
                0x6D,  //"5"
                0x7D,  //"6"
                0x07,  //"7"
                0x7F,  //"8"
                0x6F,  //"9"
                0x77,  //"A"
                0x7C,  //"B"
                0x39,  //"C"
                0x5E,  //"D"
                0x79,  //"E"
                0x71,  //"F"
                0x76,  //"H"
                0x38,  //"L"
                0x37,  //"n"
                0x3E,  //"u"
                0x73,  //"P"
                0x5C,  //"o"
                0x40,  //"-"
                0x00,  //熄灭
                0x00  //自定义
 
                         };*/
unsigned char code c[]={  //weixuan
    0x7f,
    0xbf,
    0xdf,
    0xef,
    0xf7,
    0xfb,
    0xfd,
    0xfe,

};
unsigned char code d520[]={       //520
    0x3f,
    0x5b,
    0x6d,

};
sbit we=P2^7;
sbit du=P2^6;
#define uchar unsigned char
#define uint unsigned int
void main()
{
    uchar i;
    uchar j;
   
    uint t1=100;
    for(j=0;j<6;j++)
    {
        while(t1--)
        {
             for(i=0;i<3;i++)
             {
                 du=1;
                P0=d520[i];
                du=0;
   
                we=1;
                P0=c[(j+i)];
                we=0;
                delay(1);
             }
        }
    }

        
}