ECSS-E-50-12A – SpaceWire – Links, nodes, routers and networks (24 January 2003)

This standard has been cancelled and replaced by ECSS-E-ST-50-12C (31 July 2008).


This Standard specifies 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-topoint, serial data communication links.

The scope of this Standard is the physical connectors and cables, 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. SpaceWire does not specify the contents of the packets of information.

This Standard covers the following protocol levels:

  • Physical level: Defines connectors, cables, cable assemblies and printed circuit board tracks.
  • Signal level: Defines signal encoding, voltage levels, noise margins, and data signalling rates.
  • Character level: Defines the data and control characters used to manage the flow of data across a link.
  • Exchange level: Defines the protocol for link initialization, flow control, link error detection and link error recovery.
  • Packet level: Defines how data for transmission over a SpaceWire link is split up into packets.
  • 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.