| 摘要 |
PURPOSE:To attain accurate communication for hand-shake by passing a control signal at a time and a data signal at other time through one and same line through the use of a switching signal outputted from a CPU to constitute the titled device with less space. CONSTITUTION:A transmission/reception switching signal 9 goes to a low level, a gate 10 of a transmission circuit changeover device 2 is set and an output of a data generating circuit 3 controls a driving transistor (TR) 19. On the other hand, a gate 16 of a reception circuit changeover circuit 6 is set and the input data is inputted to a transmission control circuit 8. The transmission control circuit 8 receives a signal from a reception circuit 5 to judge whether or not an external device is in the reception state, and when the reception preparation state, the circuit 8 outputs a data from a data generating circuit 3. The transmission/reception switching signal 9 goes to a high level, a gate 11 of the transmission switching circuit 2 is set and an output of a reception control circuit 4 controls the driving TR 19. On the other hand, the gate 15 of the reception circuit switching circuit 6 is set and the input data is inputted to a data detection circuit 7.
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