Patent ID: 8108585

Claim:
Crossbar circuitry for interconnecting a plurality of source circuits and a plurality of destination circuits such that data input to the crossbar circuitry from any of said plurality of source circuits can be output to any of said plurality of destination circuits, the crossbar circuitry comprising: a plurality of data input paths passing through said crossbar circuitry, each data input path being connectable to one of said plurality of source circuits; a plurality of data output paths passing through said crossbar circuitry transverse to the plurality of data input paths, each data output path being connectable to one of said plurality of destination circuits; a crossbar cell associated with each intersection between one of said data input paths and one of said data output paths, each crossbar cell comprising: storage circuitry programmable to store a routing value, the routing value being programmed to a first value to indicate that data input along the data input path to the associated intersection is to be output on the data output path at the associated intersection, and the routing value being programmed to a second value to indicate that data input along the data input path to the associated intersection is not to be output on the data output path at the associated intersection; and transmission circuitry operable in a transmission mode of operation to be responsive to the routing value having said first value 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; and control circuitry for issuing control signals to the crossbar cells, during a configuration mode of operation the control circuitry re-utilising at least one of the data output paths to program the storage circuitry of one or more of the crossbar cells.