Spacewire

SpaceWire utilizes asynchronous communication and allows speeds between 2 Mbit/s and 400 Mbit/s.

Quick Explanation

  • Allows speeds between 2 Mbit/s and 400 Mbit/s
  • Provides bit formats, routing, flow control and error detection in hardware
  • Supports wider set of speeds for data transmission
  • Features automatic failover
  • Propagation of time interrupts over SpaceWire links

Protocol

  • SpaceWire is a spacecraft communication network based in part on the IEEE 1355 standard . It is coordinated by the European Space Agency (ESA), NASA, JAXA and RKA. Additional support is provided for IEEE 1355 DS-DE The following Protocol ID's have been assigned in ECSS-E-ST-50-11:
  • 1: Remote Memory Access Protocol (RMAP)
  • 2: CCSDS Packet Transfer Protocol
  • 238: Proposal for Reliable Data Delivery Protocol (RDDP) (used on GOES-R)
  • 239: Serial Transfer Universal Protocol (STUP) (Used on SMCS-332 ASIC)

Spacewire

VisualSim Spacewire modeling environment is a hardware and software architecture simulation system for spacecraft, satellite, rocket and aircraft systems. The Spacewire library consists of switch, links and nodes blocks that can be constructed in any possible topology. These nodes can be connected at the nodes to the computing terminals such as communication equipment, navigation systems, avionics, instrumentation and other electronics. To complete the whole system design, the Spacewire network can be connected to Serial Rapid IO, PCIe and Gigabit Ethernet works. Within a node, the Spacewire can be used to connect a network of FPGAs, Processors and other custom hardware accelerators. The Spacewire network and the node devices have fully embedded performance, power and behavior characteristics. The modeling environment can be used to evaluate traffic loading, capacity utilization, power consumption, end-to-end latency and the response time for a sequence of application tasks. The library comes with detailed documentation, multiple modeling templates and pre-built statistics. In addition, the user can embed the implementation characteristics that would affect performance and power consumption, such as the differences in FPGA, software on processor and ASIC.

SpaceWire is a spacecraft communication network based in part on the IEEE 1355 standard of communications. It is coordinated by the European Space Agency (ESA) in collaboration with international space agencies including NASA, JAXA and RKA. Within a SpaceWire network the nodes are connected through low-cost, low-latency, full-duplex, point-to-point serial links and packet switching wormhole routing routers. SpaceWire covers two (physical and data-link) of the seven layers of the OSI model for communications.

SpaceWire is defined in the European Cooperation for Space Standardization ECSS-E50-12A. This defines the links, nodes, routers and networks. The library block contains the physical interconnection media and data communication protocols to enable the reliable sending of data at high-speed (between 2 Mb/s and 400 Mb/s) from one unit to another. SpaceWire links are full-duplex, point-to-point, serial data communication links. The scope of this library is the electrical properties, and logical protocols that comprise the SpaceWire data link. SpaceWire provides a means of sending packets of information from a source node to a specified destination node. VisualSim SpaceWire supports any contents in the packet.

This model covers the following protocol levels:

  1. Character level: Defines the data and control characters used to manage the flow of data across a link.
  2. Exchange level: Defines the protocol for link initialization, flow control, link error detection and link error recovery.
  3. Packet level: Defines how data for transmission over a SpaceWire link is split up into packets.
  4. Network level: Defines the structure of a SpaceWire network and the way in which packets are transferred from a source node to a destination node across a network. It also defines how link errors and network level errors are handled.

The protocol is not encrypted and can be fully visualized by the user. The user is free to make any changes, without royalty, to meet the specific characteristics and constraints of a space project in conformance with ECSS-S-ST-00.

Spacewire in a flight avionics system