Unbalanced multiplexer and arbiter combination

摘要

A method and apparatus for high speed signal path arbitration and transfer of a plurality of source signals to a destination signal path, is provided. An arbiter system includes an arbiter and a multiplexer. The multiplexer includes a plurality of n inputs each coupled to receive a source signal from one of a plurality of source signal paths and an output coupled to provide an output signal to the destination signal path. The multiplexer is controlled by a plurality of n select signal values received from the arbiter. The arbiter is coupled to receive a plurality of request signal values which prompt the arbiter to control the multiplexer to pass one of the source signals to the destination signal path. The multiplexer includes a plurality of n multiplexer signal paths each extending from one of n multiplexer inputs to the multiplexer output. Time characteristics of each of the n multiplexer signal paths are unequal. Request signal transfer times are required by the arbiter for providing a select signal value corresponding to each of the n request signal values. In the present invention, the time characteristics of the multiplexer signal paths and the request signal transfer times are matched such that an arbiter system transfer time, required to process one of the request signal values over the arbiter and pass a source signal from the corresponding multiplexer input to the multiplexer output, is approximately equal for each of the inputs to the multiplexer.