| 摘要 |
PURPOSE:To check all terminals in a short time by providing a pull-up circuit, and a pull-down circuit, on input/output terminals of a memory card, and input/ output terminals of a reader/writer, respectively, and reading its connecting state. CONSTITUTION:A bus line 8 of a memory card 14 is connected to a power source 16 through a resistance 15 and pulled up. A bus line 9 of a reader/writer 12 is connected to an earth through a resistance 17 and pulled down. A second contact point 7 of their connecting part 13 becomes open and, an input/output port 9 of a CPU 10 used as a control circuit becomes Low. On the other hand, a first contact point 6 of the connecting part 13 becomes connected, the potential of bus lines 4, 5 becomes high, and the input/output port of the CPU 10 becomes High. In this state, the CPU 10 reads a High level and a Low level of the input/output port of the CPU 10, by which the connecting state to the connecting part 13 is decided. |
