Scalable SpaceWire backplane system using µTCA

In space instrumentation, a new-generation network interface called SpaceWire has been gaining its momentum following the standardization by the European Space Agency and the European Cooperation for Space Standardization. SpaceWire, providing a high-speed peer-to-peer serial data link and network capability, can be used as an infrastructure of intra-satellite data communication, and replaces a legacy shared-bus type data transfer interface such as MIL-STD-1553B. The paper presents our recent development of SpaceWire Backplane, a uTCA-based backplane system which interconnects AMC cards with SpaceWire links. Physically, a SpaceWire link consists of 4 LVDS pairs, and therefore, a uTCA backplane can be used without almost no modification from the original design which assumes PCI express and GigabitEthernet as data link protocol. Several types of AMC modules (CPU/FPGA boards) with SpaceWire links are available together with a SpaceWire Router module attached to the MCH. Using 12-AMC-slot crate and our Generic SpaceWire I/F AMC module (4 external SpaceWire ports) for example, one can construct a system which has 48 SpaceWire links at maximum. This is considerably large compared to those available from other parties (typically providing 1-8 SpaceWire links per system). Thanks to this scalability, the SpaceWire Backplane system has been adopted in a SpaceWire network test of a satellite simulating mission instrument electronics. The system will also be useful in high-energy particle experiments where large-scale data processing and data transfer are critical.