ds12c887时间显示乱码而且只有秒是在走

请帮忙看下哪里有错
#include
#include"74hc595.h"
#include"boardinit.h"
#include"delay.h"
#include"lcd1602.h"
#include"clock.h"
#include"keyscan.h"

#define uchar unsigned char
#define uinit unsigned int

uchar time=0;
uchar miao,fen,shi;

***it as_ds12c887=P1^2;
***it ds_ds12c887=P1^0;
***it rw_ds12c887=P1^1;

void ds12c887_init()
{
      write_byte_74hc595(0x02);
}

void write_ds12c887(uchar add_ds12c887,uchar data_ds12c887)/*写数据*/
{
      as_ds12c887=1;
      ds_ds12c887=1;
      rw_ds12c887=1;
      P0=add_ds12c887;
      as_ds12c887=0;
      rw_ds12c887=0;
      P0=data_ds12c887;
      as_ds12c887=1;
      rw_ds12c887=1;
}

uchar read_ds_ds12c887(uchar add_ds12c887)/*读数据*/
{
      uchar ds_date;
      as_ds12c887=1;
      ds_ds12c887=1;
      rw_ds12c887=1;
      P0=add_ds12c887;
      as_ds12c887=0;
      P0=0xff;
      ds_ds12c887=0;
      ds_date=P0;
      as_ds12c887=1;
      ds_ds12c887=1;
      return ds_date;
}

void main()
{
      ds12c887_init();
      boardinit();
      lcdinit();

      disp_1602(1,1," 2015-07-14 ",16);
      disp_1602(1,2," 08:11:00 ",16);
      while(1)
      {
            miao=read_ds_ds12c887(0);
            fen=read_ds_ds12c887(2);
            shi=read_ds_ds12c887(4);
            write_twoline(5,shi);
            write_twoline(8,fen);
            write_twoline(11,miao);
            /*
            keyscan();
            clock();*/
      }
}