Patent ID: 6925520

Claim:
A crossbar switch, comprising: a plurality of input sorting units, each input sorting unit capable of receiving from a respective device an access request to any one of a plurality of physical memory devices; a plurality of merge and interleave units, each merge and interleave unit capable of arbitrating among competing access requests received from any of the input sorting units, selecting one of the competing access requests and forwarding the selected request for implementation on a respective memory device; wherein each merge and interleave unit includes: a priority generator for each input sorting unit capable of generating a composite request priority from a plurality of characteristics of the access requests and a plurality of operational characteristics; a priority compare circuit capable of selecting one access request; a request multiplexer controlled by the priority compare circuit to output the selected access request; a plurality of programmable registers; a decode unit receiving the selected request from the request multiplexer to determine whether the selected request is a register operation and, if so, to send a plurality of control and data signals to the registers; and an output multiplexer for combining register read data with request data for output.