spacefibre spw wg april 2012 -...

SpaceFibre

Steve Parkes1, Chris McClements1, Martin Dunstan1

Albert Ferrer2, Alberto Gonzalez2

1Space Technology Centre, University of Dundee. UK

2STAR-Dundee Ltd, UK1

Contents Requirements Standard Complexity Implementation Flight Projects Demonstration Next Steps SpaceWire-RT

2

SpaceFibre Requirements SpaceFibre Objectives

– Compatible with SpaceWire At the packet and network levels

– High speed 2 Gbits/s now (2.5 Gbit/s signalling) 5 Gbits/s planned (6.5 Gbits/s signalling)

– Very high speed Multiple lanes e.g. 4 lanes 8 Gbits/s

– Galvanic isolation– Copper and fibre optic implementations

5 m copper 100 m optical fibre

– Low mass cable 60 g/m copper 30 g/m fibre3

SpaceFibre Target SpaceFibre capabilities to the space

application– Very high-speed – Point-to-point– Virtual networks– Virtual circuits– Low latency signalling– Integrated networks

FDIR QoS

4

Qualitative RequirementsDistance Rate Latency Packet size QoS

Data-handling network

Short to long Low to very high

Not important Short to long Reserved bandwidth

Control bus Short to long Low Low Short to long Deterministic delivery

Telemetry bus Short to long Low Low Short Reserved bandwidth

Computer bus Short Very high Low Short to long Reserved bandwidth

Time-sync bus Short to long Low Very low Short High priority

Side-band Short Low to high Very low Short High priority

5 Russian/European Requirements from SpaceWire-RT project (Submicron)

VHiSSI(Very High Speed Serial Interfaces)

Set of Requirements for SpaceFibre-HSSI

6

The VHiSSI project has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement no. 284389

VHiSSI

7

The Consortium University of Dundee STAR-Dundee ACE-IC RAMON chips IHP ASTRIUM EIT


VHiSSI

8

Overview


VHiSSI

9

Primary Applications SpaceWire to SpaceFibre Bridge Instrument to Mass Memory or Processor Mass Memory from Instruments Mass Memory to Downlink Telemetry Downlink Telemetry from Mass Memory Control Processor controlling instruments and other units Data Processor Array Integrated Avionics Network Long distance control connection for launcher using Fibre

Optics


VHiSSI

10

Use Case - Bridge


VHiSSI

11

Main characteristics of the SpaceWire to SpaceFibre Bridge

SpaceWire to SpaceFibre Bridge Remarks

Number of SpaceWire links At least 8At least 4

Using LVTTLUsing LVDS(configurable)

Number of virtual channels (number of VC buffers (VCB) is twice the number of VCs due to bi-directional manner)

At least 8 Minimum: one VC for each SpaceWire link

Configuration SpW link None(option)

At least one SpW link can be used for configuration

SpW transmit rate 10, 50, 100, 200, 400, 300 (TBC)

Configurable per SpW link

Parallel interface none

Characteristics - Bridge


VHiSSI

12

Use Case - Instrument


VHiSSI

13

Main characteristics of the VHiSSI chip in instrument modeinstrument mode Remarks

Parallel interface (FIFO-type) with:-interface clock-write-signal-programmable full signal-programmable empty signal (TBC)-VCB-addresses-data (in)-EOP-marker (in)-Interrupt signal

All inputs and outputs are LVTTL.All data lines shall be configured as inputs.

Number of virtual channels At least 2 One VC for (instrument) data. One additional VC for other kind of information (like housekeeping data, control, status)

Configuration SpW link 1 A LVTTL-SpW link is used for configuration and control (C&C), can also be used to configure the instrument/module.

SpW transmit rate 10, 50, 100, 200, 400 (TBC)

selectable for configuration SpW link

Characteristics - Instrument


VHiSSI

14

Application SpaceWire to SpaceFibre Bridge

– Provide options for LVDS or LVTTL interfaces (8 pins and 4 pins per SpaceWire interface respectively)

– Multiplex as many SpaceWire connections as possible over SpaceFibre– Be able to send and receive over either SpaceFibre interface– At least one SpaceWire interface shall be able to configure the VHiSSI

chip– Configuration over either SpaceFibre interface shall be possible


VHiSSI

15

Application Instrument to Mass Memory or Processor

– Very high data rate from instrument– Data to go to mass-memory or processor using point-

to point link or virtual point-to-point link which requires a single virtual channel for the data.

– Instrument likely to contain FPGA providing the data.– FPGA might be a slow device (< 100 MHz IO) or a

faster device (>100 MHz IO).– Instrument will need to be configured and controlled

over SpaceFibre.– Configuration, status monitoring and control of the

VHiSSI chip shall be via either SpaceFibre interface or via a local (e.g. SpaceWire) interface


VHiSSI

16

Application Mass memory from Instruments

– Receive data from several instruments each with varying data rates, e.g. one very high data rate instrument or several SpaceWire instruments connected via a SpaceWire to SpaceFibre Bridge.

– Many virtual channels from different instruments likely to be multiplexed over each SpaceFibre interface. The number of VCs will determine the number of instruments that can be connected using virtual point-to-point links.

– Each instrument has a point-to-point link or virtual point-to-point link to the mass memory.

– Mass memory likely to contain FPGA receiving the data and passing it on to memory modules.

– It shall be possible to provide configuration, status monitoring and control information to and from the mass memory via either SpaceFibre interface.

– Configuration, status monitoring and control of the VHiSSI chip shall be via either SpaceFibre interface or via a local (e.g. SpaceWire) interface.

SpaceFibre Standard

17

SpaceFibre Overview

18

Retry InterfaceRetry Layer

Encoding/Decoding InterfaceEncoding Layer

SerDes InterfaceSerialisation Layer

Virtual Channel Layer

VC Interface

Serial InterfacePhysical Layer

Lane Control InterfaceLane Control Layer

Lane InterfaceLane Layer

Broadcast Interface

Broadcast Layer

Framing LayerFrame Interface

Equivalent toSpaceWireCODEC

QoS &FDIR

Multi-Lane

SpaceFibre Layers Virtual Channel:

– Quality of service and flow control Broadcast:

– Broadcasts short messages across network Framing:

– Frames information to be sent over link– Scrambles SpaceWire packet data

Retry:– Recovers from transient and persistent errors

19

SpaceFibre Layers

Lane Control:– Runs several SpaceFibre lanes in parallel– Provides higher data throughput and redundancy

with graceful degradation Lane:

– Lane initialisation, error detection and re-initialisation

Encoding/Decoding:– Encodes data into symbols for transmission

Serialisation:– Serialises SpaceFibre symbols

Physical:– Fibre optic or copper medium.20

SpaceFibre Standard

21

Retry InterfaceRetry Layer

Encoding/Decoding InterfaceEncoding Layer

SerDes InterfaceSerialisation Layer


VC Interface

Serial InterfacePhysical Layer

Lane Control InterfaceLane Control Layer

Lane InterfaceLane Layer

Broadcast Interface

Broadcast Layer

Framing LayerFrame Interface

SpaceFibre QoS Simple approach Low implementation cost Versatile Provides integrated QoS scheme

– Priority VC with highest priority

– Bandwidth reserved VC with allocated bandwidth and recent low utilisation

– Best Effort VC can send when no other VC ready to send

– Scheduled Time-slots defined by broadcast messages VCs allocated to specific time-slots In allocated time-slot, VC allowed to send22

Medium Access Controller

23

Frames FCTs

VC B

UFF

ER

RX FCTDECODE

Output VCBs

Medium AccessController

VC B

UFF

ER

VC B

UFF

ER

VC B

UFF

ER

Medium Access Controller Determines

– Output VCB permitted to send next frame Depends on:

– Which output VCBs have data to send– Which input VCBs at other end of link have room – Arbitration or QoS policy in force for each virtual

channel

24

QoS: Bandwidth Reserved

25

time

12

3

Precedence

Bandwidth Credit Counter


26

time

Precedence


27

time

1 2

Precedence


28

time

Precedence


29

time

1 2

3

MinimumBandwidthCredit

QoS: Scheduled

30

time

1 2

MinimumBandwidthCredit

QoS Priority

31

time

Priority 1

Priority 2

Priority 3

FDIR Support in QoS Bandwidth credit counter also supports fault

detection:– Excessive bandwidth utilisation

When BW credit counter reaches negative limit

– Under utilisation of allocated bandwidth When BW credit counter stays at maximum limit for long

period of time

Can be used to detect– Babbling idiots– Faulty units

All provided with simple, low cost, mechanism

32

SpaceFibre Complexity

33

Complexity Comparison against

– SpaceWire CODEC– SpaceWire RMAP– Rapid IO

Actual implementation figures– Eight VCs– Estimate for retry– No laning

34

Complexity About 3x more complex than SpaceWire

35

SpaceFibreLane

SpaceWireCODEC

SpaceFibreCODEC

SpaceWireRMAP+CODEC

LUTs 1033 329 5184 1667FF 955 385 3029 1329

0

1000

2000

3000

4000

5000

6000C

ompl

exity

Complexity: SpaceFibre vs SpaceWire

Complexity Similar complexity to Rapid IO

36

Rapid IO Total SpF CODECLUTs 5400 4491FF 5250 3038

0

1000

2000

3000

4000

5000

6000C

ompl

exity

Complexity: SpaceFibre vs Rapid IO

Rapid IO v2.1 x1 (Based on Xilinx srio_ds696, Spartan 6 results)

Implementing SpaceFibre

37

Implementation Physical Layer

– Examples– Copper cable/connectors– Fibre Optics

CODEC IP Core Test and development equipment

38

Physical Layer Connectors SpaceFibre specification

– Characteristics of cable and connectors– If possible open specification of specific

implementation Example high performance connectors

– Axon AxoMach– Designed for spaceflight applications– Very high bandwidth– Cable assemblies– PCB mounting connectors– Cable mass 60 g/m for SpFi full duplex– Connector mass approx 25 g

39

axoMachtm (R&T CNES)

• 2 coaxials space cable media ax2.4S per way• 100 Ohm differential impedance• Up to 10Gb/s per way (1,2 &4 ways)• Low skew• Low size• E.M.I. improved• Surface mount & parallel gap PCB terminations

16/05/2012

INNOVATIVE SPACE INTERCONNECT HIGH

SPEED DATA TRANSMISSION UP TO 40 Gb/s

40

Design : heritage of microD

• MicroD space contacts• PTFE inserts (Zc=100 Ohms)• twin‐coaxials (2 times ax2.4S)• EMI gasket• Retractable jack screw

41

INNOVATIVE SPACE INTERCONNECT HIGH

SPEED DATA TRANSMISSION UP TO 40 Gb/s

Female inline

Male inline

ESA Presentation | DD/MM/YYYY | Slide 44

ESA UNCLASSIFIED – For Official Use

Diamond Connectors

ESA Contract – Diamond (CH)Diamond connectors with space heritage currently undergoing formal ESCC Evaluation and Qualification Diamond AVIM Connector

Mass 6gLength 60mm

Diamond Mini-AVIM ConnectorMass 1gLength 27mm

Evaluation of connectors has been completed using a step stress approach (ESCC Basic Specification No. 2263010) . Qualification proposal is under approval. Qualification testing should be completed by Q3 2012



Evaluation of a Fibre Optic Cable Assembly

ESA Contract - GSTP Parallel Contracts awarded - Fibre Pulse (Ir) and T&G Elektro (N)

Objectives:• Collect space user requirements• Screen optical fibre, connector and cable suppliers• Trade-off and select cable assemblies• Manufacture cable assemblies• Perform a first evaluation (thermo/mechanical testing)

Results should be available Q4 2012

Both simplex and parallel optical cables to be examined.



Radiation Darkening Test Results

Annealingafter

radiation exposure has been

completed

When space dose rates are considered radiation darkening appears not to be a serious issue for commercial and rad-hard GI fibres at 850nm.

With the exception possibly at very low temperatures!



Transceiver Sensitivity to Radiation

• VCSELS and PIN diodes have proven to perform well in the space radiation environment – small active area.

• Laser drivers have shown some sensitivity to SEE (results are still being analysed)



Space Fibre 2

ESA Contract - ARTES 5.1Prime: Patria Aviation Oy Systems (Fin)Subcontractors: VTT (Fin) and Dlightsys (F) - transceiver manufacture

Alter (E) – optical component test houseThales Alenia Space (F) - end user

Objective:To develop an Engineering Model (EM) of a high speed fibre-optic transceiver (>6.25Gbps) for use onboard telecom satellites consolidated through testing.

Test Readiness Review held 20.04.2012Mechanical, thermal, life test, outgassing, TID, end-user and SpaceWire network tests to be performed on Dlightsys and VTT modules.

Test results should be available by Q4(Patria to provide further details of progress)



Planned Space Environment Testing on Space Fibre 2 Modules

• Random Vibration: 50 g rms (100-2000Hz)• Shock Testing: 3000g at 10kHz (5 shocks per axis)• Life Test: 2000 hours at Max. Case temperature• Thermal Cycling: -55°C … +125°C (operational at least 500 cycles)• Radiation Testing

• Gamma TID 100 krads• Single Event Effects - Heavy Ion Testing (different energy levels

up to 15, 35 and 70MeV)• Proton 1012 Fluence

• Material Outgassing• Leak Test• Moisture Resistance Test• ESD



Current Applications of

Fibre Optics

SMOS – Optical CommsData and Clock Distribution

PROBA 2 – Fibre Optic Sensor NetworkISS - Optical Communications

Demeter - Optopyro

Planck - FOG

SpaceFibre CODEC SpaceFibre CODEC IP

– Generic number of virtual channels– Broadcast channels– Full QoS support– FDIR– Designed to operate with several SerDes

Developed by UoD and STAR-Dundee Will be available from ESA

– For use on ESA missions Will be available from STAR-Dundee

– For other missions Alpha customer testing in summer 2012

51

SpaceFibre Test and Development Kit SpaceFibre to USB interface SpaceFibre to PCIe interface SpaceFibre Link Analyser

– USB or PCIe versions SpaceFibre EGSE

– USB or PCIe versions

52

SpaceFibre USB Interface

Two SpaceFibre interfaces Two SpaceWire interfaces USB interface SpaceFibre pattern generators Eight virtual channels Full QoS GUI to configure53

SpaceFibre PCIe Interface

Two SpaceFibre interfaces PCI Express interface SpaceFibre pattern generators Eight virtual channels Full QoS GUI to configure

54

SpaceFibre Link Analyser

SpaceFibre Link Analyser and Monitor External logic analyser connections Internal logic analyser

– Configured over USB interface– Extensive triggering capability– Large capture memory– Various data display modes

55

SpaceFibre EGSE

Extensive pattern generation capability Scripting language to define

– Packets– Schedules– States

Very simple to simulate an instrument SpaceWire and SpaceFibre versions USB and PCIe platforms56

Spaceflight Capable Designs

57

FPGA Implementation

Flight FPGA Implementation– Using ESA/UoD IP Core– External SerDes TLK2711-SP– Copper and Fibre versions– Flight board to be designed– Contract to be placed by ESA/UoD– Q3/4 2012

58

FPGAe.g.

Actel ProASIC

TLK2711SerDes

VML to

CMLSpFiIO


VHiSSI VHiSSI Chip Implementation VHiSSI FP7 Project

– Aim Very High Speed Serial Interface (VHiSSI) technology for

space applications Radiation tolerant SpaceFibre device

– Team University of Dundee STAR-Dundee Ltd Astrium GmbH Ramon Chips ACE-IC IHP Euro Instruments Trading

59


VHiSSI VHiSSI Chip Implementation VHiSSI chip specification

– High speed serial interface 2.5 Gbits/s (at least)

– Fully integrated SpaceFibre interface Including QoS and FDIR

– Two SpaceFibre ports– Low power– Small size

20 x 14 mm

– Radiation tolerant– ITAR free technology

60


VHiSSI VHiSSI Chip Implementation VHiSSI chip modes

– SpaceWire to SpaceFibre Several SpaceWire interfaces Connected to SpaceFibre virtual channels Mix of LVDS and LVTTL interfaces

– Various other interface modes Designed for simple interfacing to

– FPGA– Memory– Processors

61


VHiSSI VHiSSI Chip Implementation VHiSSI Chip Implementation

62

ESA Projects Using SpaceFibre

63

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NGMMANext Generation Mass MemoryArchitecture

DDR2-SDRAM&

NAND FlashMemory Module

High SpeedInput & Output

Interface Controller

Memory System Supervisor

&Network

Simulator

Data High WayConfigurationReal Time Control

Test Equipment

Next Generation Mass MemoryTeam Astrium GmbH IDA University of Dundee

Objective High capacity High I/O bandwidth Flexible architecture Radiation tolerant memory devices Mass memory for future space applications

64

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NGMMANext Generation Mass MemoryArchitecture Next Generation Mass Memory

65

SpaceFibreNetwork

IOController

SpaceFibre

SpaceWire

NGMMController

MemoryModules

MemoryModules

MemoryModules

MemoryModules

MemoryModules

MemoryModules

MemoryModules

MemoryModules

MemoryModules

MemoryModules

InstrumentInterfaces

Downlink

High Performance COTS based Computer step II ESA led activity (GSTP funded)

Aims to build a demonstrator of a COTS based payload data processor

Planned end of study : December 2013

Aims at defining a framework that can accommodate a range of COTS processors

Date - 66

High Performance COTS based Computer use of SpF Aimed at payload data

processing

Computations on Processor Modules, error mitigation by SMART IO

High rate instrument data buffered on SMART IO and then forwarded to PMs

RMAP over SpF between SMART IO and PMs

Date - 67

High Processing Power DSP Team

– Astrium Ltd– STAR-Dundee Ltd– CG Space

Objective– DSP system for space applications– High performance– Wide bandwidth interfaces– Flexible interfaces

SpaceFibre SpaceWire GPIO

68

High Processing Power DSP

69

DSP

IOFPGA

Memory

SpaceFibre

SpaceWire

GPIO

Japanese SpaceFibre projects NEC and Melco are both developing

SpaceFibre interfaces Will be tested for interoperability with UoD

– in November 2012

70

Demonstration

71

SpaceFibre Demo Unit Architecture

72

VC/BCIF

Reg

USB 3

Router

SpW

SpW

1

2

56

SpaceFibrePort 1

(8 Virtual Channels)

SpF

AnalyserMictor

VC/BCIF

SpaceFibrePort 2

(8 Virtual Channels)

Reg

78

Analyser

SpF

Mictor

RMAP Config(RMAP Target)

4

Configuration Bus

Virtual Channel Interfaces

73

SpaceFibre CODEC

VC 3-6Data Generator

VC 3-6Data Checker

VC 3-6

VC 7Data Generator

VC 7Data Checker

VC 7

Reg

iste

rs

QO

S

Fram

ing

SpW to SpF

SpF to SpWVC 0

SpW to SpF

SpF to SpWVC 1

VC 0Data Generator

VC 0Data Checker

VC 2

SpW

Rou

ter

VC 3-6Data Generator

VC 3-6Data Checker

VC 3-6

Demonstration Set Up

74

SpaceFibreInterface

Unit

SpaceFibreInterface

Unit

SpaceFibreLab Cables

TriggerCable

USBCablesto PC

What will be demonstrated Link initialisation Data frames and idle frames Broadcast frames QoS: Bandwidth Reserved QoS: Best Effort QoS: Priority SpaceWire over SpaceFibre

75

76

Active Active

Start

NearEndStarted

Start

NearEndStarted

BothEndsStarted

BothEndsStarted

Link Initialisation - Handshaking


77

AUTOSTARTSTART

NearEndStarted

FarEndStarted

BothEndsStarted

Start Tx Auto-Start Tx


78

AUTOSTART

(Data) ActiveActive (Data)

START

NearEndStarted

FarEndStarted

BothEndsStarted

HalfConn

Start Tx Auto-Start Tx

Control Words & Frames

79

• FCTs- Control of the RX Buffer empty space

• ACKs- Confirmation of the reception of frames

• Idle Frames- Keep the link active with low EMC

Control Words & Frames

80

• Data Frames- Encapsulate user data into independent

virtual channels with the requested quality of service

• Broadcast Frames- Highest priority to distribute critical

information through the network

Quality of Service - Bandwidth Reservation

81

Virtualchannel

Sourcedata rate

BwAllocated

BwMeasured

2 45 % 50 % 45 %3 45 % 50 % 45 %

Virtualchannel

Sourcedata rate

BwAllocated

BwMeasured

2 45 % 50 % 45 %3 100 % 50 % 55 %

Quality of Service – Priority of Service

82

Virtualchannel Priority

Sourcedata rate

BwAllocated

BwMeasured

2 High 45 % 50 % 45 %3 High 100 % 50 % 55 %


Sourcedata rate

BwAllocated

BwMeasured

2 Low 45 % 50 % 0 %3 High 100 % 50 % 100 %

Quality of Service – Priority of Service

83


Sourcedata rate

BwAllocated

BwMeasured

2 High 20 % 25 % 20 %3 Medium 20 % 25 % 20 %4 Medium 20 % 25 % 20 %5 Low 20 % 25 % 20 %


Sourcedata rate

BwAllocated

BwMeasured

2 High 20 % 25 % 20 %3 Medium 20 % 25 % 20 %4 Medium 50 % 25 % 50 %5 Low 20 % 25 % 10 %

Complex configuration

84


Sourcedata rate

BwAllocated

BwMeasured

BC - - - -0 High ~ 7 % 10 % ~ 7 %1 High ~ 7 % 10 % ~ 7 %2 Highest 10 % 15 % 10 %3 Medium 10 % 15 % 10 %4 Medium 10 % 15 % 10 %5 Medium 10 % 15 % 10 %6 Low 10 % 20 % 10 %7 Low 10 % 20 % 10 %

SpaceFibre Next Steps

85

SpaceFibre FDIR FDIR

– Fault detection Parity/disparity Invalid 8B/10B codes CRC Over and under utilisation of expected bandwidth

– Fault isolation Galvanic isolation Data framing – time containment Virtual channels – bandwidth containment

– Fault recovery Link level retry Graceful degradation on lane failure Babbling idiot protection Error reporting

86

SpaceFibre Next Steps Finish implementation of retry layer ESA/UoD ITT for SpaceFibre developments

– Issue ITT– Kick off activities

Support alpha-site customers– Variety of implementation targets– Variety of application areas

Update SpaceFibre specification– Taking into account

Implementation experience Feedback from SpaceWire working group Alpha-site feedback

87

SpaceWire-RT

EU FP7 ProjectRussian and European Partners

SUAI, SubMicron, ELVEESUniversity of Dundee, Astrium GmbH

88

The SPACEWIRE-RT project has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement no. 263148

Aims

89

Distance Rate Latency Packet size QoS

Data-handling network

Short to long Low to very high

Not important Short to long Reserved bandwidth

Control bus Short to long Low Low Short to long Deterministic delivery

Telemetry bus Short to long Low Low Short Reserved bandwidth

Computer bus Short Very high Low Short to long Reserved bandwidth

Time-sync bus Short to long Low Very low Short High priority

Side-band Short Low to high Very low Short High priority


Trade-OffsTable 10-1 Trade-Off of Alternative Solutions

Trade‐Off SpFi‐LVDS SpFi‐OS‐LVDS SpFi over SpW SpFi‐SpW‐8B12B

SpFi‐8B12B

Speed Range 10‐600 Mbits/s

1 to 50 Mbits/s

1 to 300 Mbits/s

1 to 200 Mbits/s

1 to 200 Mbits/s

Low Power Yes Yes No No NoLow Mass Yes Yes No No NoQualified FPGA

No Yes Yes Yes Yes

PLL needed PLL No PLL No PLL No PLL No PLLGalvanic Isolation

Yes Yes No Yes Yes

Compatible with SpaceWire

No No Yes No No

Efficient coding

Yes Yes Yes No No

Significant modification

No No No Yes Yes

90


SpaceFibre over SpaceWire

91

Lane Interface

Retry Interface


Retry Layer

SpaceWire Link Layer

VC Interface

Frame Interface

Framing Layer

Lane Control Interface

Lane Control Layer

Broadcast Interface

Broadcast Layer


SpaceFibre over SpaceWire

92

EDF

SDF

EOP

EOP

DA

EDF

SDF

EDF

SDF

SDF

EOP

EDF

EDF

SDF

EDF

SDF

EOP

DA

EDF

SDF

EOP

DA

SDF

EOP

EDF

EOP

DA

Application SpaceWire Packet

Application SpaceWirePacket Segmented inSpaceFibre Frames

SpaceFibre Frames in SpaceWire Packets

SpaceWire-RT Protocol Stack

93

Lane Interface

Retry Interface


Retry Layer

Lane Layer

VC Interface

Frame Interface

Framing Layer

Lane Control Interface

Lane Control Layer

Broadcast Interface

Broadcast Layer

Encoding Interface

Encoding Layer

Serialisation Interface

Serialisation Layer

Physical InterfaceCopper CMLFibre Optic Copper

LVDS

Lane Interface

Packet Interface

SpaceWire Exchange Level

Encoding Interface

SpaceWire Character Level

SpaceWire Signal LevelCopper LVDS

Physical Interface

Frame Encapsulation

Preliminary CharacteristicsTable 11-1 SpaceWire-RT Protocol Characteristics

Characteristic SpFi‐FO SpFi‐CML SpFi‐ LVDS SpFi over SpWMedia Fibre Optic Copper CML Copper LVDS Copper LVDSEncoding 8B/10B 8B/10B 8B/10B Data‐StrobeSpeed Range 0.1 to 20 Gbits/s

50 Gbits/s in future0.1 to 20 Gbits/s50 Gbits/s in future

1 to 600 Mbits/s1 to 50 Mbits/s OS

1 to 300 Mbits/s

Distance 100 m 5 m 10 m 10 mGalvanic Isolation Yes Yes Yes NoPacket Size Arbitrary Arbitrary Arbitrary ArbitrarySpaceWire Packet Level

Yes Yes Yes Yes

Latency (TBC) 1 µs 1 µs 1 µs 10 1 µsCable Mass < 30g/m < 60g/m < 40g/m ~87 g/mPower (TBC) < 200 mW < 200 mW < 200 mW < 400 mWQoS BW Reserved Yes Yes Yes YesQoS Priority Yes Yes Yes YesQoS Scheduled Yes Yes Yes YesQoS Best Effort Yes Yes Yes YesBroadcast Message Yes Yes Yes YesDeterminism Yes Yes Yes YesReliability Yes Yes Yes YesFault Detection Yes Yes Yes YesFault Isolation Yes Yes Yes YesRetry Yes Yes Yes YesSpaceWire compatible Packet level only Packet level only Packet level only Yes 94

Summary SpaceFibre designed for spacecraft

– SpaceWire packets– Very high speed– QoS and FDIR

Specification– Initial draft under review– CODEC implemented and under test– Retry function to be added– Specification to be updated by end 2012

Radiation tolerant implementations– FPGA with external SerDes– VHiSSI ASIC– Physical layer components available

95

Summary SpaceWire-RT aims to

– Extend SpaceFibre to cover– Broad range of space applications– Including mixed data-handling and avionics

96

spacefibre spw wg april 2012 -...

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