Crossbar circuitry and method of operation of such crossbar circuitry

Abstract

Crossbar circuitry, and a method of operation of such crossbar circuitry, are provided. The crossbar circuitry has an array of data input paths and data output paths where the data output paths are transverse to the data input paths. At each intersection between a data input path and a data output path, a crossbar cell is provided that comprises a storage circuit programmable to store a routing value, and a transmission circuit. In a transmission mode of operation the transmission circuit is responsive to the routing value indicating that the data input path should be coupled to the data output path to detect the data input along the data input path, and to output an indication of that data on the data output path at the associated intersection. Control circuitry is used to issue control signals to the crossbar cells, and during a configuration mode of operation the control circuitry re-utilizes at least one of the data output paths to program the storage circuitry of one or more of the crossbar cells. Such a construction of crossbar circuitry provides a very regular design, with uniform delay across all paths, and which requires significantly less control lines than typical prior art crossbar designs. Such crossbar circuitry is readily scalable to form large crossbars.