Networks, CCSDS SOIF and Support Tools: SpaceWire Research at Dundee ESTEC May 2003

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Networks, CCSDS SOIF and Support ToolsSpaceWire
Research at DundeeESTECMay 2003

• Stuart Mills, Chris McClements, Steve Parkes
• Space Systems Research Group
• University of Dundee

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Contents

• SpaceWire Introduction
• SpaceWire Interface VHDL
• SpaceWire Router
• CCSDS SOIF and higher level protocols for
  SpaceWire
• SpaceWire Development Support Tools

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SpaceWire

• SpaceWire is a computer network for use onboard
  spacecraft
• Connects together
• Sensors
• Memory
• Processing subsystems
• Down-link telemetry subsystem
• Point to point
• Bi-directional
• Full duplex
• High-speed 2 Mbits/s to 400 Mbits/s
• Cable or PCB trace / backplane
• Low Voltage Differential Signalling
• Data-Strobe encoding

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SpaceWire Standard

• European Cooperation for Space Standardization
• ECSS-E50-12A
• Thanks to SpaceWire Working Group
• Particularly
• Josep Rosello-Guasch
• Philippe Armbruster
• Enrique-Gonzalez-Conde Lopez

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SpaceWire Interface VHDL

• Funded by ESA
• Link Interface developed by University of Dundee
• Test Bench developed by Austrian Aerospace and
  University of Dundee
• Evaluation by Austrian Aerospace, Astrium and
  ESTEC
• Will be available from ESA

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SpaceWire Interface VHDL
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SpaceWire Router

• Eight SpaceWire ports.
• External parallel port
• Comprises input FIFO and output FIFO.
• Non-blocking crossbar switch
• connects an input port to any output port.
• Internal configuration port
• accessible via the crossbar switch
• from the external parallel port
• or the SpaceWire ports.
• Routing table
• accessible via the configuration port
• holds the logical address to output port mapping.

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SpaceWire Router

• Control logic to control the operation of the
  switch
• performing arbitration
• and group adaptive routing.
• Control registers
• written and read by the configuration port
• hold control information e.g. link operating
  speed.
• External time-code interface
• comprising tick_in, tick_out
• and current tick count value.
• Internal status/error registers
• accessible via the configuration port
• External status/error signals

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SpaceWire Router
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SpaceWire-RouterUSB

• Eight port SpaceWire router
• FPGA prototype for SpaceWire Router ASIC
• Operates at 200 Mbps
• External port connected to USB 2.0 interface
• Unit operates from single 5V power supply

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SpaceWire-RouterUSB
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SpaceWire-RouterUSB
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CCSDS SOIF

• Spacecraft Onboard Interfaces Panel
• Consultative Committee for Space Data
  Standardization
• Specifying standards for spacecraft onboard
  interfaces
• Aim to provide
• A standard for satellite onboard interfaces
• Enable separation of software from underlying
  hardware
• Encourage reuse
• Enhance reliability
• Do this without incurring high performance
  penalties

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SOIF Protocol Stack
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TCP/IP over SpaceWire Evaluation System
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TCP/IP over Ethernet and SpaceWire
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TCP/IP over SpaceWire Effect of changing MTU
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SpaceWire Development Support Tools

• SpaceWire-PCI
• SpaceWire-PCI Drivers
• Windows,
• Linux,
• VxWorks
• SpaceWire-RouterUSB
• SpaceWire-Monitor
• SpaceWire-DSP
• SpaceWire-PCI-2

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SpaceWire Monitor

• Monitors traffic on a SpaceWire link
• Two banks of LEDs show
• connection state
• Data flow
• EOPs/EEP
• NULLs
• FCTs
• Errors
• Logic analyser connections
• Break-out decoded SpaceWire signals
• For analysis of what is happening on the link
• Both directions monitored simultaneously

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SpaceWire-Monitor
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SpaceWire Monitor

• Logic Analyser Images

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SpaceWire Monitor

• Logic Analyser Images

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SpaceWire-DSP
External RAM 512k x 64-bits
ADSP-21160 DSP Processor
SpaceWire Router
SHARC LINKS
External RAM 512k x 64-bits
SpaceWire Links
Boot EPROM
JTAG Port
POWER SUPPLY
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SpaceWire-PCI-2
SMCS FPGA
DUAL-PORT MEMORY
SpaceWire Interfaces
PCI INTERFACE
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SpaceWire Research

• SpaceWire is being accepted widely for Space
  applications
• Recent research at Dundee has focused on a range
  of issues related to SpaceWire
• Supporting the adoption of SpaceWire
• SpaceWire Interface VHDL
• SpaceWire Router
• Developing support equipment and tools
• Researching higher level protocols