The GRSPWROUTER IP core is a VHDL model of a SpaceWire routing switch as defined in the ECSS-E-ST-50-12C standard. The core is highly configurable, flexible and portable to a wide variety of FPGA and ASIC technologies. The core supports all mandatory and optional features in the ECSS-E-ST-50-12C standard and can be configured from the minimum number of ports 2 to the maximum 31. In addition to this there is the mandatory configuration port. The configuration port provides access to configuration and status registers and the routing table using the Remote Memory Access Protocol (RMAP) defined in ECSS-E-ST-50-52C. The SpaceWire Plug-and-Play (PnP) protocol can optionally be supported on the configuration port.