Apparatus for providing conflict-free highway access

• Main Author: READ; EDGAR L
• Format: Patent
• Language: English
• Published: 03.12.1985
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; PHYSICS

An interface apparatus, which interfaces a communication device to a highway wherein the highway includes a clock line, a data line, and a busy line, comprises a counter element which counts a clock signal transmitted on the clock line to generate a clock value. The counter includes a second input terminal connected to the busy line to disable the counting when a busy signal is present on the busy line. A compare element compares the clock value to a device number value associated with the communication device, each communication device coupled to the highway having a unique device number value, and outputs an enable signal when the clock value and the device number value are equal. A driver element permits data to be transmitted onto the data line in response to the enable signal when the communication device has data to be transmitted. The driver element further causes the busy signal to be generated and coupled onto the busy line of the highway thereby disabling the counter elements of each interface apparatus connected to the highway.