Bus organized structure with variable arbitration means

Abstract From the Canadian patent

A variable priority arbitration scheme to control access by plural peripheral devices to a common data bus in which each peripheral device transmits a priority byte before transmitting data, monitors the data bus for a bit collision on a bit by bit basis, and on detection of a bit collision disables transmission increments its priority byte and repeats all steps until access to the bus is gauged and data transmission is completed. The priority byte is such that each peripheral is guaranteed access to the bus within a predetermined number of attempts.