| 摘要 |
PURPOSE:To control a subscriber equipment in multi-point connection for access of a common channel by providing a common channel access control circuit comprising a data transmission/reception LSI for single point access and a simple accessory circuit to each subscriber equipment. CONSTITUTION:When a frame transmission start/end identification circuit 3 detects the transmission of head of a data frame for data transmission/reception LSI1 and a common channel idle detection circuit 6 does not detect any idle state at the data transmission of a subscriber equipment TEi, the common channel access control circuit CNT stops the supply of transmission clock to the said LSI1 to bring it into standby state. When idle state is detected in the said standby state, the supply of transmission clock is started to start transmission to a common channel of the data frame, missing of data due to transmission collision is prevented by writing the data transmitted by the LSI1 to a transmission buffer at the same time to stop the transmission of a frame subject to collision, and just after the common channel is idle, the buffer 2 transmits automonously again the said data frame. |
