Presentation is loading. Please wait.

Presentation is loading. Please wait.

ESTEC/ TOS-ETD section www.estec.esa.nl/tech/spacewire 1 University Of Dundee APPLIED COMPUTING SpaceWire 1.Scope 2.Standard ECSS-E-50-12, Draft-1 3.Layers.

Similar presentations


Presentation on theme: "ESTEC/ TOS-ETD section www.estec.esa.nl/tech/spacewire 1 University Of Dundee APPLIED COMPUTING SpaceWire 1.Scope 2.Standard ECSS-E-50-12, Draft-1 3.Layers."— Presentation transcript:

1 ESTEC/ TOS-ETD section 1 University Of Dundee APPLIED COMPUTING SpaceWire 1.Scope 2.Standard ECSS-E-50-12, Draft-1 3.Layers above the Standard 4.Space vs commercial digital technologies

2 ESTEC/ TOS-ETD section 2 University Of Dundee APPLIED COMPUTING SpaceWire Networks Point-to-point links –Serial digital links : Mbit/s - typical distance: 10 meters –Bi-directional (full-duplex) –Good EMC characteristics – low power consumption - –Scaleable, low cost, low latency Nodes –A source or a destination of a packet (e.g. a processor, memory unit, sensor, Ground Support Equipment Routers –Switch connecting several links that routes packets from one link to another

3 ESTEC/ TOS-ETD section 3 University Of Dundee APPLIED COMPUTING Node Point-to-point serial links SpaceWire Interface Devices (chips) Example Cascaded routers Nodes Network Router

4 ESTEC/ TOS-ETD section 4 University Of Dundee APPLIED COMPUTING Electrical Ground Support Equipment (EGSE) Computer Unit Instrument Mass Memory Module Digital Processing Unit SpaceWire Router SpaceWire links SpaceWire Network SpaceWire Basic Communications infrastructure Processor EM

5 ESTEC/ TOS-ETD section 5 University Of Dundee APPLIED COMPUTING Board for On-Board Processing 8kx32 DPRAM In red : 1355 / SpaceWire related modules TSC (DSP) BOOT PROM Back side: 128kx40 (DM) 128kx48 (PM) SRAM Support FPGA SpaceWire connectors LVDS Two SMCS-332 Encoder / Decoder

6 ESTEC/ TOS-ETD section 6 University Of Dundee APPLIED COMPUTING Node SpaceWire Interface (part of a chip) Node Additional logic for System on a Chip Channel 1 Ch. 2 Ch. 3 Glue logic (e.g. FIFO, Checksum) COMIHOCICOMIHOCI JT AG Device for a SpaceWire node SMCS332 RxDS TxDS Space Wire SpcW routersCascaded (Simple: approximately 5000 gates) ENCODER DECODER RECEIVE FIFO TRANSMIT FIFO Interface to Host Data Strobe Data Strobe STATE MACHINE 8 bits

7 ESTEC/ TOS-ETD section 7 University Of Dundee APPLIED COMPUTING SpaceWire Standard Physical Level Signal Level Character Level Exchange Level Packet Level Network Level Recovery Schemes (Recommendations)

8 ESTEC/ TOS-ETD section 8 University Of Dundee APPLIED COMPUTING Application Presentation Session TOPNET Layers Data-Link Physical Application Software Transport Network UDP / TCP-like ? IP-like CCSDS-SOIF ( ) Physical Signal Character Exchange Network Packet SpaceWire Levels (legacy from IEEE 1355)

9 ESTEC/ TOS-ETD section 9 University Of Dundee APPLIED COMPUTING Physical Level Physical Level covers –Cables 4 screened twisted pairs with overall shield –Connectors 9 pin micro-miniature D-types –Cable Assemblies –PCB / backplane tracking

10 ESTEC/ TOS-ETD section 10 University Of Dundee APPLIED COMPUTING Cable Construction Conductor 28 AWG (7 x 36 AWG) Insulating layer Twisted pair Inner shield around twisted pair (40AWG) Outer shield (38AWG) Outer Jacket Filler Jacket Filler Binder

11 ESTEC/ TOS-ETD section 11 University Of Dundee APPLIED COMPUTING Signal Level Signal Level covers:- –Electrical characteristics –Signal coding –Signal timing –EMC recommendations

12 ESTEC/ TOS-ETD section 12 University Of Dundee APPLIED COMPUTING SpaceWire Links Point to point Bi-directional (Full duplex) High-speed 2 Mbits/s to 400 Mbits/s Low power 0.5 W per link interface Mbps) Cable or PCB trace / backplane LVDS Data-Strobe encoding LINK (LVDS + Cable/PCB) FIFO TYPE INTERFACE FIFO TYPE INTERFACE LINK INTERFACE LINK INTERFACE

13 ESTEC/ TOS-ETD section 13 University Of Dundee APPLIED COMPUTING SpaceWire Link Interface ENCODERDECODER RECEIVE FIFO TRANSMIT FIFO Interface to Host SpaceWire Link Micro- Miniature D-Type Data Strobe LVDS Data Strobe LVDS STATE MACHINE 8 bits

14 ESTEC/ TOS-ETD section 14 University Of Dundee APPLIED COMPUTING SpaceWire Link Interface (as it is presented in the Standard) Receiver Transmitter State Machine Tx Clock Rx clock Recovery D S D S Clock 8 // bits ENCODER DECODER RECEIVE FIFO TRANSMIT FIFO Data Strobe Data Strobe STATE MACHINE 8 bits Figure 7-1 of the SpaceWire Std, Draft-1 =

15 ESTEC/ TOS-ETD section 15 University Of Dundee APPLIED COMPUTING Physical Signal Character Data-Link Exchange Network Packet SpaceWire Levels (legacy from IEEE 1355) SpaceWire Application Software Intelligent node Local-EGSE Application Software Intelligent node On-Board Application Software

16 ESTEC/ TOS-ETD section 16 University Of Dundee APPLIED COMPUTING SpaceWire Network Interconnected with SpaceWire links Alternative paths give the redundancy Node 1Node 2 Router 1 Router 2 Router 3

17 ESTEC/ TOS-ETD section 17 University Of Dundee APPLIED COMPUTING SpaceWire Error Recovery Link Errors –Disconnect error –Parity error –Escape sequence error –Credit error –Empty packet error Network Errors –Link error –EEP received –Destination address error Recommendation of possible actions : –Examples : Disconnect link / Discard packet / report to higher level (e.g. application)

18 ESTEC/ TOS-ETD section 18 University Of Dundee APPLIED COMPUTING On-Board Buses for Command& Control Mil-Std-1553 –Max. 1 Mbit/s –Asynchronous –Half-duplex (one-direction at a time) –American On-Board-Data-Handling –Max. 512 kbit/s –Synchronous –Full-duplex (bi-directional) –European

19 ESTEC/ TOS-ETD section 19 University Of Dundee APPLIED COMPUTING Similar Standards for On-Board Space Interfaces IEEE 1394 (FireWire) same Data-Strobe Scheme and LVDS=> data rates 100 – 200 and 400 Mbit/s

20 ESTEC/ TOS-ETD section 20 University Of Dundee APPLIED COMPUTING SpaceWire New generation of High Speed Serial Links Unified high-speed interface all over the Spacecraft 2 Mbps < Variable data rates < 400 Mbps and scalable with number of cables High-speed gives margin for above layers overheads => sort of Intranet possible in the S/C It is bi-directional: required for DSPs, and allows remote configuration/control of camera/SSMM Routers allow dynamic switching (packets switched according to Header Content) A large number of nodes can be reached with a reduced number of cables => seamless communication intra-box (backplane) and inter-box (cable) => good for SW It is reliable => Robust physical level => BER < Mbps = 1 error every 11.5 days In addition: Detection of disconnect and Parity errors + Link restart Redundant paths are available On top of SpaceWire, Network / Transport Layers for further protection Enabling end-to-end model (HW and SW) for high-speed interfaces => Facilitates SOFTWARE developments: message passing & Virtual Channels High speed links can talk to computers on-board => Intranet possible in the S/C Possibilities for integration / testing via Internet – Just a Gateway is needed

21 ESTEC/ TOS-ETD section 21 University Of Dundee APPLIED COMPUTING Methodology 2) between units EGSE 3) directly with EGSE => many other features (see next presentation) TOPNET complements the OSI (CCSDS-SOIF) model with Network / Transport Layers 4) as a gateway to the Internet Internet SpaceWire provides the high-speed network infrastructure for communications 1) within the unit SpaceWire Router SpaceWire links

22 ESTEC/ TOS-ETD section 22 University Of Dundee APPLIED COMPUTING Topnet: Features summary TopNet at a glance –Provides an end to end solution –SpaceWire infrastructure –Network / Transport Layers & FDIR –Frame for a de-centralised and progressive functional Integration. –Interface to the Internet Benefits to Users –Reduces development risks/costs by allowing early pre-integration –Fosters complete compatibility and modules re-use

23 ESTEC/ TOS-ETD section 23 University Of Dundee APPLIED COMPUTING Defying traditional mindset Projects interested in –what other projects did before (reliability, cost) –Availability of components and modules –Standards => compatibility, re-use => cost, time to market –Potential gains in the short term More R&D budget needed to prove concepts first

24 ESTEC/ TOS-ETD section 24 University Of Dundee APPLIED COMPUTING Conclusion SpaceWire provides the infrastructure to have a sort of Internet On-Board the Spacecraft A large number of Spacecraft in the U.S. and Europe –use SMCS devices based on IEEE 1355 –plan to use SpaceWire and its routers The Network/Transport Layers have to be further defined


Download ppt "ESTEC/ TOS-ETD section www.estec.esa.nl/tech/spacewire 1 University Of Dundee APPLIED COMPUTING SpaceWire 1.Scope 2.Standard ECSS-E-50-12, Draft-1 3.Layers."

Similar presentations


Ads by Google