A scalable, high-performance interconnect scheme for a multi-threaded, multi-processing system-on-a-chip network processor unit. An apparatus implementing the technique includes a plurality of masters configured in a plurality of clusters, a plurality of targets, and a chassis interconnect that may be controlled to selectively connects a given master to a given target. In one embodiment, the chassis interconnect comprises a plurality of sets of bus lines connected between the plurality of clusters and the plurality of targets forming a cross-bar interconnect, including sets of bus lines corresponding to a command bus, a pull data bus for target writes, and a push data bus for target reads. Multiplexer circuitry for each of the command bus, pull data bus, and push data bus is employed to selectively connect a given cluster to a given target to enable commands and data to be passed between the given cluster and the given target.