| 摘要 |
PURPOSE:To reduce the number of connecting ports of two or more kinds of ex- ternal peripheral devices of different data sending and receiving systems so as to ecomonize the space of an information processor, by giving two or more kinds of functions to one connecting port and switching the functions. CONSTITUTION:An information processor 10 has a connecting port 11 and the connecting port 11 becomes a connecting port for input and that for output by switching. To be concrete, when ''0'' is written on a flip-flop 110, the connecting port 100 becomes the one for output, because a tri-state buffer 140 becomes active and another tri-state buffer 150 becomes inactive. When ''1'' is written in the flip-flip 110, the connecting port 100 becomes the one for input, because the tri- state buffer 150 becomes active and the other tri-state buffer 14 becomes inactive. Therefore, the one connecting port 11 can deal with either of two kinds of external peripheral devices 20 and 30 of different data sending and receiving systems. |
