| 摘要 |
PURPOSE:To make high speed and highly efficient circuit connection without a program and without casting a burden on the device or software by providing transfer request using a break signal, a transmission acceptable signal line and a receiving acceptable signal line without having any troublesome procedure. CONSTITUTION:The transmission controlling section 10 of a communication controlling device 2 sends out a break signal from a break issuing circuit 12 to a receiving data RD line 15 at the time of transmission request. The break signal is expressed by an OFF period of more than 16 bits, and can be distinguished clearly from ordinary start-stop system data. The break signal is detected by a break detecting circuit 5 of a communication controlling device 1 and a receiving controlling section 3 is started by interruption. When the controlling section 3 starts receiving action, a signal SR is sent from an interface circuit 8 to a transmission acceptable signal SR line 18. The signal SR is received by an interface circuit 13 of the device 2 as a receiving acceptable signal PR, and data transmission okay is indicated in the controlling section 10.
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