CHANNEL SELECTION SIGNAL CONTENTION CONTROLLER FOR CATV RECEIVER

摘要

PURPOSE:To prevent the contention of selection signals by transmitting a channel selection signal while turning a bus to a using state after passing time adding different discrimination numbers set in respective receivers and a waiting time set in advance when the bus is decided in an idle state. CONSTITUTION:A CPU 337 applies a control signal to a driver 37 from an I/O control circuit 340, and the bus is turned to be high impedance by the driver 37. The CPU 337 decides whether the channel selection signal is transmitted or not, waits when the channel selection signal is not transmitted, and sets the time of (T+nt) to a timer when to be transmitted. When a BS tuner 33a completes the transmission of the channel selection signal and the bus becomes a non-active state, the CPU 337 decides whether the timer firaishes counting of the time of (T+nt) or not, decides the state of the bus again when it is not finished, and transmits the channel selection signal to turn the bus to high impedance when the timer finishes counting the time of (T+nt).