Abstract: A bus expander bridge is provided for interfacing first and second external buses (such as PCI buses) to a third bus. The bus expander bridge is configurable in either an independent mode in which the first and second external buses operate independently and a combined mode in which the first and second external buses are combined to create a single bus. The bus expander bridge includes a first set of data queues for routing data between the first external bus and the third bus, and a second set of data queues for routing data between the second external bus and the third bus. The bus expander bridge also includes a controller coupled to the first and second sets of data queues and operating the first and second sets of data queues in parallel for the independent mode. The controller routes even addressed data through the first set of data queues and routes odd addressed data through the second set of data queues for the combined mode.

Abstract: A method for processing an atomic transaction in a multi-bus system that includes a local bus and a remote bus. According to the method, a first transaction in an atomic sequence is received from the local bus. The first transaction is terminated on the local bus. The first transaction is performed on the remote bus. A response to the first transaction is received and the response is placed on the local bus.