An apparatus may include a first system and a second system. The first system includes a first plurality of interface circuits, and each of the first plurality of interface circuits is configured to couple to a separate interface. The second system includes a second plurality of interface circuits, and each of the second plurality of interface circuits is configured to couple to a separate interface. A first interface circuit of the first plurality of interface circuits and a second interface circuit of the second plurality of interface circuits are coupled to a first interface. Both the first interface circuit and the second interface circuit are configured to communicate packets, coherency commands, and noncoherent commands on the first interface.