Modular fabric internal datapath

Described is an apparatus comprising one or more router circuitries. One or more of the circuitries may be a shared-bus router circuitry including a plurality of shared-bus ports and a shared-bus datapath, and one or more of the circuitries may be a crossbar router circuitry including a plurality of crossbar ports and a crossbar datapath. Also described are methods of making the apparatus, which may include: providing one or more design files modeling the apparatus, the shared-bus datapath, and the crossbar datapath; incorporating a configuration parameter for the datapath into the one or more design files; and setting an RTL configuration parameter to instantiate either the shared-bus backbone or the crossbar backbone. The methods may also include loading the one or more design files with a design tool and compiling the one or more design files with the design tool.