Abstract: A number, Y, of ports are coupled to a common bus and to a bus arbitration extension device. The extension device is coupled to X pairs of arbitration signal lines, where X is less than Y. The extension device controls the assertion and receipt of request and grant signal in response to a control input which can be controlled by the operation of system software or BIOS. For example, two of the ports share one pair of arbitration signal lines under the control of the extension device and its control input. In a preferred embodiment of the present invention, a port that is empty or contains a non bus master device or a device that infrequently initiates transfers over the bus shares arbitration signal lines with a standard bus master device. The bus arbitration extension device allows for selectively controlling the access of components to an arbiter or the like based on the control input.

Abstract: A printed circuit board having a selectable circuit routing configuration comprises a substrate, a plurality of electrical traces mounted to the substrate for interconnecting electrical components, and at least one fusible connector mounted to the substrate. Each of the fusible connectors has a fuse line formed from a conductive layer of the printed circuit board and forms a fusible connection between at least two of the electrical traces. The circuit routing configuration can be selected by application of a predetermined current through at least one of the fusible connectors to break the fusible connection formed by the fusible connector.