Abstract: The CATV system includes a center device and a plurality of terminal devices. The center device sends downstream timeslots, to the terminal devices, including upstream timeslots occupancy information and collision information. Upstream timeslot occupancy information indicates whether or not an upstream timeslot corresponding to the downstream timeslot is vacant, and collision information indicates whether or not a collision has occurred. The terminal device receives the downstream timeslot, checks upstream timeslot occupancy information to detect upstream timeslot in the vacant state, and sends upstream data to the center device via the vacant upstream timeslot. If the upstream timeslot makes a collision, the center device detects it and sends a downstream timeslot which includes collision information indicative of the occurrence of the collision. The user of the terminal device recognizes the collision having occurred or not by referring to the collision information.

Abstract: The CATV system includes a center device and a plurality of terminal devices. The center device sends downstream timeslots, to the terminal devices, including upstream timeslot occupancy information and collision information. Upstream timeslot occupancy information indicates whether or not an upstream timeslot corresponding to the downstream timeslot is vacant, and collision information indicates whether or not a collision has occurred. The terminal device receives the downstream timeslot, checks upstream timeslot occupancy information to detect upstream timeslot in the vacant state, and sends upstream data to the center device via the vacant upstream timeslot. If the upstream timeslot makes a collision, the center device detects it and sends a downstream timeslot which includes collision information indicative of the occurrence of the collision. The user of the terminal device recognizes the collision having occurred or not by referring to the collision information.

Abstract: A CATV telephone system includes a center device and a plurality of terminal devices connected by wired communication lines. The center device receives a request data from the terminal device, examines the frequency bands and the time slots currently occupied, allocates non-busy frequency bands and non-busy time slots to the transmission frequency band, the transmission time slot, the reception frequency band and the reception time slot, and notifies the allocation to the terminal device. Then, the terminal device transmits telephone data to the center device using the transmission frequency band and the transmission time slot designated by the center device, and receives telephone data from the center device using the reception frequency band and the reception time slot designated by the center device.

Abstract: In a multiprocessor system comprising a primary processor and at least one subsidiary processor, the primary processor carries out an operation by the use of a predetermined address space divided into first and partial address spaces assigned to the primary processor and to both the primary and the subsidiary processors in common, respectively. The primary processor is coupled to a primary local memory defining the first partial address space while each subsidiary processor is coupled to a common memory to which the second partial address space is assigned by dividing the second partial address space. Each common memory is coupled to the primary processor through a first gate circuit and to each subsidiary processor through a second gate circuit. The first and the second gate circuits are controlled by a controlled to selectively connect the primary and each subsidiary processors to the common memory and to thereby share the same with the primary and each subsidiary processors.