The OpenSoC Fabric is an ongoing project to create a open source network-on-chip generator capable of creating a synthesizeable network for connecting processors, memory and I/O devices.
Being written and designed in Chisel, OpenSoC Fabric is completely hierarchical and parameterizable. Standard interfaces for all modules make it easy for you to drop in different implementations or write your own. The hierarchical nature also provides a top-down parameter definition, allowing you to easily define parameters for the whole network.