子程序名称：dtocdw
功能：将一个双字型数据转化为以0结束的十进制字符串，并输出于指定位置
参数：ax=双字型数据低16位
      dx=双字型数据高16位
      ds:si指向字符串首地址
返回：无
 DTOCDW:  PUSH      CX
              PUSH      SI
              PUSH      AX
              PUSH      DX
     
              SUB       CX,CX
              PUSH      CX
 DTOCDW_DIV:  MOV       CX,10
              CALL      DIVDW
              ADD       CX,30H
              PUSH      CX
              MOV       CX,AX
              JCXZ      DTOCDW_DIV_LOK
              JMP       SHORT DTOCDW_DIV
         DTOCDW_DIV_LOK:  MOV       CX,DX
              JCXZ      DTOCDW_TRANS
              JMP       SHORT DTOCDW_DIV
              
           DTOCDW_TRANS:
              POP       CX
              JCXZ      DTOCDW_TRANS_OK
              MOV       [SI],CX
              INC       SI
              INC       CX
              LOOP      DTOCDW_TRANS
        DTOCDW_TRANS_OK:
              POP       DX
              POP       AX
              POP       SI
              POP       CX
              RET


              
           
      DIVDW:  PUSH      BP
              PUSH      AX
              MOV       AX,DX
              SUB       DX,DX
              DIV       CX
              MOV       BP,SP
              MOV       [BP-2],AX
              POP       AX
              DIV       CX
              MOV       CX,DX
              MOV       DX,[BP-2]
              POP       BP
              RET