In an embodiment, one or more fabric control circuits may be inserted in a communication fabric to control various aspects of the communications by components in the system. The fabric control circuits may be included on the interface of the components to the communication fabric, in some embodiments. In other embodiments that include a hierarchical communication fabric, fabric control circuits may alternatively or additionally be included. The fabric control circuits may be programmable, and thus may provide the ability to tune the communication fabric to meet performance and/or functionality goals.