Modifications of an Asynchronous Ring Arbiter

Some modifications of an asynchronous ring arbiter are proposed. This arbiter is composed of a chain of cells. Each cell has one to one correspondence to a device. In the chain, there exists only one privilege to arbitrate conflicts of requests from many devices. A class of modifications is high speed arbiters, obtained by increasing the number of connecting wires between two adjacent cells. As the results, the time required for the privilege to pass through a cell decreases by about one-half compared with the original arbiter. Another class of modifications is arbiters with priority rules. They are obtained by adding a few hardware to the original arbiter. The priority order of request acknowledgements in all the cells is specified. Using above modifications, conflicts of requests in many digital systems may be feasibly arbitrated.