For each MI that can be accessed by multiple SIs, round-robin arbiters in the MI select the read command (AR channel) and write command (AW channel) to issue from the MI. A new read/write command can be issued each clock cycle, regardless of whether re-arbitrating a command from a different SI, or issuing a subsequent command from the same SI (back-to-back command arbitration). Commands presented to different MIs can be arbitrated and issued concurrently.
For each SI that accesses multiple MIs, round-robin arbiters in the SIs select among the R-channel and B-channel responses returned from the various MIs. These arbiters also support back-to-back transfers. Along the R-channel, the response arbiters support interleaving of read data beats among multiple MIs, without waiting for the end of the read burst (rlast) before re-arbitrating.