BUS-BASED PRIORITY ARBITRATION SYSTEM WITH OPTIMUM CODEWORDS

A bus-based priority arbitration system employs optimum priority codewords to arbitrate in time t. For m arbitration busses, each priority codeword has m bits and at most t intervals of consecutive 0's or consecutive 1's, disregarding leading consecutive 0's. The arbitration busses are wired-OR busses. An arbitration protocol performed by the modules involved in an arbitration process applies respective codewords of the contending modules to the arbitration busses, each bit on a different bus. The codewords insure that the modules determine from the arbitration busses the contending module of highest priority in at most t units of time. Also, the arbitration system defines priority codewords as a function of arbitration time and number of aribitration busses which enables design optimization of a desired arbitration system. In one case, the number of arbitration busses m required in a system of n supportable modules is defined by the relationships 1 g n .ltoreq.m.ltoreq. 1 g n +1 and t= 1/21 g n .