Multiple client memory arbitration system capable of operating multiple configuration types

Claim 1

A multiple client memory arbitration system for a cache memory in an I/O controller device having a plurality of internal clients of said cache memory and at least one external client of said cache memory, said system comprising: an arbitrator of said cache memory in said I/O controller device; means for selecting a configuration type for said I/O controller device selected from a group of configuration types consisting of: unknown device configuration, single device configuration, multiple device master configuration, and multiple device slave configuration, wherein said arbitration system is capable of operating said unknown device configuration, said single device configuration, said multiple device master configuration, and said multiple device slave configuration, and wherein said means for selecting said configuration type includes means for defining a configuration field in a register of said I/O controller, means for programming said configuration field with a selected one of said configuration type, and means for testing said configuration field at arbitraton device initialization time to identify said configuration type; means for configuring said arbitrator of said cache memory based on said configuration type; means for refreshing said cache memory at any time independent of said configuration type; and means for executing failover control of said cache memory in an event of an I/O controller device failure in a multiple device configuration.