CROSSBAR DEVICE, MULTISTAGE CROSSBAR DEVICE AND INFORMATION PROCESSOR

摘要

PROBLEM TO BE SOLVED: To provide a multistage crossbar device capable of performing request sequence assurance with a simple configuration. SOLUTION: A small-scale crossbar device 10 provided with an input buffering part 11, a crossbar switch 12 and an output buffering part 13 including plural output buffers is provided with an other crossbar output buffer state monitoring part 14 which monitors the output buffering parts of the other small- scale crossbar devices belonging to the same processing stage of the multistage crossbar device and an output buffer busy generating part 15 which generates an output buffer busy signal in accordance with its output. The other crossbar output buffer state monitoring part obtains the absolute value of the number of requests in every connection destination of each output buffer and outputs maximum write request number information. The output buffer busy generating part decides if write should be stopped in every output buffer based on the maximum write request number information and the states of the output buffering part of a self-crossbar and the input buffering part.