steve parkes , chris mcclements -...

SpaceFibre

Steve Parkes1, Chris McClements1, Martin Dunstan1

Albert Ferrer2, Alberto Gonzalez2

1Space Technology Centre, University of Dundee. UK

2STAR-Dundee Ltd, UK 1

Contents SpaceFibre Applications SpaceFibre Network Level SpaceFibre Standard Update

2

SpaceFibre Applications

3

Instrument 2Interface

Data Output

Local Instrument


Data Output

Local Instrument

Data BusTo Memory

Mass Memory Unit

Mass MemoryInterface


4


Data Output

SpaceWireTo

SpaceFibre Bridge

SpaceWireInstrument

SpaceWireInstrument

SpaceWireInstrument

SpaceWireInstrument

Data Output

Data Output

Local Instruments

Remote Instruments

Local Instrument


Data Output

Local Instrument

Data BusTo Memory

Mass Memory Unit



5


Data Output

SpaceWireTo

SpaceFibre Bridge

SpaceWireInstrument

SpaceWireInstrument

SpaceWireInstrument

SpaceWireInstrument

Data Output

Data Output

Local Instruments

Remote Instruments

Local Instrument


Data Output

Local Instrument

Data BusTo Memory

Mass Memory Unit


Downlink TelemetryInterface

Data Output

Downlink Telemetry


6

Instrument 2InterfaceSpW Control/HK

Data Output

SpaceWireTo

SpaceFibre Bridge

SpaceWireInstrument

SpaceWireInstrument

SpaceWireInstrument

SpaceWireInstrument

SpW Control/HKData Output

SpW Control/HKData Output

Local Instruments

Remote Instruments

Local Instrument

SpaceFibreRouter

Instrument 1InterfaceSpW Control/HK

Data Output

Local Instrument

Mass MemoryInterface Data Bus

To Memory

Mass Memory Unit

Downlink TelemetryInterface SpW Control/HK

Data Output

Downlink Telemetry

ControlProcessorInterface SpW Control/HK

Data Input/Output

Control Processor

Principal On-board Communications Instrument

– Data to mass-memory– Configuration and control– Housekeeping

Mass memory– Data from instruments– Data to downlink– Configuration and control– Housekeeping

Downlink– Data from mass-memory– Configuration and control– Housekeeping

7

SpaceFibre Network Level SpaceFibre transfers SpaceWire packets

– Destination address– Cargo– EOP

Path and logical addressing can be used Routing concept identical to SpaceWire VCs can be used to provide

– Virtual networks – like SpaceWire– Constrained virtual networks– Virtual point to point links

Improved FDIR

8

SpaceFibre Routing Switch

9

Routing SwitchMatrix

SpaceFibreInterface

VC

VC

VC

VC

VC

SpaceFibreInterface

VC

VC

VC

VC

VC

SpaceFibreInterface

VC

VC

VC

VC

VC

SpaceFibreInterface

VC

VC

VC

VC

VC

ConfigurationPort

Port 2 Port 3

Port 1 Port 4

SpaceFibrePort 2

SpaceFibrePort 1

SpaceFibrePort 3

SpaceFibrePort 4

SpaceFibre Virtual Network

10

SpaceFibreRoutingSwitch

VC

VC 6

VC

VC

VC

VC 6

VC

VC

VC

VC

VC 6

VC

VC

VC

VC

VC

VC

VC

VC 6

VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 6

VC

VC

SpFiI/F

ControlProcessor

VC

VC 6

VC

SpFiI/F

MassMemory

Unit

VC

VC 6

VC

SpFiI/FInstrument 2

VC

VC 6

VC

SpFiI/FInstrument 1

Virtual channel buffers are configured to support specific virtual channelsOne set of buffers is always configured to support VC 0, the Configuration Virtual Network

SpaceFibre Virtual Point to Point Link

11


VC

VC 6

VC

VC

VC

VC 6

VC 4

VC 2

VC

VC

VC 6

VC 4

VC

VC

VC

VC 2

VC

VC

VC 6

VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 6

VC

VC

SpFiI/F

ControlProcessor

VC 2

VC 6

VC 4

SpFiI/F

MassMemory

Unit

VC 2

VC 6

VC

SpFiI/F

Instrument 2

VC 4

VC 6

VC

SpFiI/F

Instrument 1

SpaceFibre Virtual Point to Point Link

12


VC

VC 6

VC

VC

VC

VC 6

VC 4

VC 2

VC

VC

VC 6

VC 4

VC

VC

VC

VC 2

VC

VC

VC 6

VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 6

VC

VC

SpFiI/F

ControlProcessor

VC 2

VC 6

VC 4

SpFiI/F

MassMemory

Unit

VC 2

VC 6

VC

SpFiI/F

Instrument 2

VC 4

VC 6

VC

SpFiI/F

Instrument 1

Simple SpaceFibre Network

13


VC

VC 6

VC

VC

VC

VC 6

VC 4

VC 2

VC

VC

VC 6

VC 4

VC

VC

VC

VC 2

VC

VC

VC 6

VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 6

VC

VC

SpFiI/F

ControlProcessor

VC 2

VC 6

VC 4

SpFiI/F

MassMemory

Unit

VC 2

VC 6

VC

SpFiI/F

Instrument 2

VC 4

VC 6

VC

SpFiI/F

Instrument 1

Spacecraft Data Handling Application

14

SpaceWire - SpaceFibre Bridge

VC 7VC 1VC 2VC 3VC 4

SpFiI/F

VC 5VC 6VC 8


VCVC 7VCVCVC


VC 7VC 1VCVCVC

VC 2VCVC

VC 7VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 7VCVC

SpFiI/F

ControlProcessor

MassMemory

Unit

VC 2VC 7VC

SpFiI/F

Instrument 2

VC 1VC 7VC

SpFiI/F

Instrument 1

VC 7VC VC

VC 8VC


SpFiPort

4

SpFiPort

1

VC 8VC 7VC

SpFiI/F

DownlinkTelemetry

VC 4VC 7VC 5

SpFiI/F

SpaceWire Router

I 3

I 4

I 5

I 6

VC 6

VC 3

VC 5VC 6VC 8

Instruments


15

ControlProcessor

MassMemory

Unit

Instrument 2

Instrument 1

DownlinkTelemetry

I 3

I 4

I 5

I 6

Instruments


16


ControlProcessor

MassMemory

Unit

Instrument 2

Instrument 1

DownlinkTelemetry

SpaceWire SpaceFibre

Bridge

I 3

I 4

I 5

I 6

Instruments

Impact on spacecraft mass Mass saving

– 13 cables 2m each 90g = 2.34 kg Replaced with

– 6 cables 2m each 60g = 0.72 kg– Saving of 1.6 kg

Plus redundancy– Saving of 3.2 kg

17

Addition FDIR capability

18


VC

VC 6

VC

VC

VC

VC 6

VC 4

VC 2

VC

VC

VC 6

VC 4

VC

VC

VC

VC 2

VC

VC

VC 6

VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 6

VC

VC

SpFiI/F

ControlProcessor

VC 2

VC 6

VC 4

SpFiI/F

MassMemory

Unit

VC 2

VC 6

VC

SpFiI/F

Instrument 2

VC 4

VC 6

VC

SpFiI/F

Instrument 1

Not allowed to use this Port since no VC 4

SpaceWire packet discarded

Can only route to same VC

VN routing to all destinations

19


VC

VC 6

VC

VC

VC

VC 6

VC

VC

VC

VC

VC 6

VC

VC

VC

VC

VC

VC

VC

VC 6

VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 6

VC

VC

SpFiI/F

ControlProcessor

VC

VC 6

VC

SpFiI/F

MassMemory

Unit

VC

VC 6

VC

SpFiI/FInstrument 2

VC

VC 6

VC

SpFiI/FInstrument 1

VN routing to restricted destinations

20


VC

VC 6

VC

VC

VC

VC

VC

VC

VC

VC

VC 6

VC

VC

VC

VC

VC

VC

VC

VC 6

VC

SpFiPort

3

SpFiPort

4

SpFiPort

2

SpFiPort

1

VC 6

VC

VC

SpFiI/F

ControlProcessor

VC

VC

VC

SpFiI/F

MassMemory

Unit

VC

VC 6

VC

SpFiI/FInstrument 2

VC

VC 6

VC

SpFiI/FInstrument 1

Not allowed to route to this port

SpaceFibre Network Level Overview of intended SpaceFibre network

operation Targeted at spacecraft data-handling

applications VC buffers configured to specific VCs Can only route information within same

VC/VN Provides additional FDIR capability Using redundancy of information

– (address and VC number)– to detect faults

Scheduling can be used with VNs for deterministic control applications21

SpaceFibre Standard Update

22

SpaceFibre Standard Update E1– Retry layer completed.– Lane initialisation state diagram simplified.– Data word identification state diagram simplified.– Control symbols changed to improve robustness.– Service interfaces improved (not yet finished).– Quality of service specification improved.– Management parameters added (more work yet).– Electrical connectors and cable assemblies added to

physical layer.– Other corrections and clarifications throughout the

document.

23

Physical Layer Connectors SpaceFibre specification

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

implementation Based on 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

24

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

12/10/2012

INNOVATIVE SPACE INTERCONNECT HIGH

SPEED DATA TRANSMISSION UP TO 40 Gb/s

25

Design : heritage of microD

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

26

INNOVATIVE SPACE INTERCONNECT HIGH

SPEED DATA TRANSMISSION UP TO 40 Gb/s

Female inline

Male inline

SpaceFibre Flight Cable Assembly

29

12

34

43

21

cable assembly

connectormale

connectormale

Individual shields

backshell

43

21

TX -TX +

RX +RX -

connectorfemale

PCBtracks

SpaceFibreCODEC

connectorbodybackshell

TX +TX -

12

34

RX -RX +

PCBtracks

SpaceFibreCODEC

connectorbody

connectorfemale

SpaceFibre Flight/EGSE Cable Assembly

30

SpaceFibre EGSE Cable Assemblies External Serial ATA (eSATA) connectors

used– Low cost– Small– High performance

Crossover cable assemblies

31

SpaceFibre EGSE Cable Assembly

32

23

1

4

56

7

65

7

4

32

1

shield

cable assembly

cable receptacle

cable receptacle

shield

B +B -

GND

GND

A -A +

GND

TX -TX +

RX +RX -

deviceplug

PCBtracks

SpaceFibreCODEC

TX +TX -

A +A -

GND

GND

B -B +

GND

RX -RX +

deviceplug

PCBtracks

SpaceFibreCODEC

SpaceFibre EGSE Cable Assembly

33

SpaceFibre Flight to EGSE Adaptor

34

43

21

cable assembly

connectormale

Individual shields

backshell

43

21

TX -TX +

RX +RX -

connectorfemale

PCBtracks

SpaceFibreCODEC

Flight Unit

connectorbody

23

1

4

56

7

cable receptacle

TX +TX -

A +A -

GND

GND

B -B +

GND

RX -RX +

deviceplug

PCBtracks

SpaceFibreCODEC

EGSE Unit

43

21

cable assembly

connectorfemale

Individual shields

backshell

23

1

4

56

7

cable receptacle

TX +TX -

A +A -

GND

GND

B -B +

GND

RX -RX +

deviceplug

PCBtracks

SpaceFibreCODEC

EGSE Unit

SpaceFibre Flight/EGSE Adaptor

35

Quality of service Reminder about the QoS mechanism

– Bandwidth reserved– Priority– Scheduled

36

Medium Access Controller

37

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

38

QoS: Bandwidth Reserved

39

time

12

3

Precedence

Bandwidth Credit Counter

QoS: Bandwidth Reserved

40

time

Precedence

QoS Priority

41

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

42

Scheduled Precedence Time divided into time-slots

– E.g. 64 time-slots of say 1 ms each Each VC allocated time-slots in which it is

permitted to send data frames During a time-slot

– If allowed to send in that time-slot– VC competes with other VCs also allowed to send

in that time-slot– Based on precedence (priority and BW credit)

A fully deterministic system would have one VC allowed to send in each time-slot

43

Scheduled Precedence

44

Time-slot 1 2 3 4 5 6 7 8VC 1VC 2VC 3VC 4VC 5VC 6VC 7VC 8

Configured for Priority and BW Reserved Only

45


Mixed Deterministic and Priority/BW-Reserved

46


SpaceFibre Update

47

Overview

1. Retry layer completed– Fastest error recovery time (3-5us at 2.5Gb/s) – Supports any link speeds (no timeouts used)– Recovers from nominal errors and detects non

nominal link error conditions (i.e. multiple bit flips)

2. Lane initialization state machine simplified– Same functionality, 40% reduction in complexity.

3. More robust control word encoding scheme– Any single bit flip in the line is ALWAYS detected

by the combination of encoding and retry layer.

4. SpaceFibre specifications completed– Management and physical layer described

48

Retry Layer features

Recovers from an error as fast as possible.– A NACK is sent when any type of error is

detected. 8B10B disparity error CRC error Out of sequence frame (data, idle, FCT..)

– Retry starts as soon as a NACK is received. Current data frame is aborted

– Broadcasts have higher priority than data frames at all times. (i.e. even when an error occurs)

49

Retry Layer features (2)

Reliable link under any type of error – Including the loss of NACKs, ACKs or any other

word.– Nominal errors (i.e. single bit flips) are always

recovered.– Non-nominal conditions (i.e. multi bit flips) are

detected before there is a change that the link reliability is compromised.

– Fatal errors such as unexpected hardware resets do not affect the link operation and user data integrity.

Supports any link speeds without configuration– It does not use timeouts, so it can work with any

link speed (i.e. multiple lanes or SpaceWire links)50

Retry Layer naïve approach

51

EDF 1

NACK 1

EDF 2

EDF 3

EDF 2NACK 1

EDF 2

Resend Data 2

Resend Data 2

If we retry every time a NACK is received, a single error can produce more than one retry event

If we send a single NACK for the first error, then this NACK could get lost.

Disparity error

Frame Sequence error

NACK 2 Frame Sequence error

Retry Layer actual operation

52

EDF +1

NACK +1

EDF +2

EDF +3

EDF -2NACK +1

EDF -3

NACK received, use negative sequences

NACK discarded because sequence is not negative

EDF -4

There are positive and negative sequence numbers (sequence polarity)

• The receiver changes the polarity when an error occurs.

• The sender changes the polarity when a NACK is received

EDF -5

The worst case recovery time is the round trip delay plus the transmission time of a data frame.

• This is less than 4us with a 100m cable length @2.5Gb/s in a prototype implementation.

Broadcasts that are delayed due to a retry event are marked with a flag in EBF word.

When a retry occurs, new broadcasts have priority over data to be resend.

A single ACK word can acknowledge more than one frame.

ACK word usage of bandwidth is limited. – 16 words must be sent between ACK words.– This helps to guarantee the bandwidth allocated

to data frames

Retry Layer additional features

53

Retry Layer TX implementation

54

Three Separate retry buffers for:1. Broadcast Frames2. FCTs3. Data frames

Retry buffer control module removes frames acknowledged by the ACKs received

The retry buffers holds frames and FCTs until they are acknowledged.

One or more retry buffer can get full if:1. The retry buffer is small and can not hold the amount of data sent

before an ACK is received.2. One or more ACKs are lost due to the cable being disconnected

and connected. We need to request to send a new ACK using the FULL word

Retry buffer full condition

55

Data 1

ACK 1

FULL

- When the retry buffer is full, a FULL word is sent

- When a FULL word is received, and ACK is sent

Data 2

ACK 2

ACK 2

Retry Layer RX implementation

56

The Demux is implemented with the word identification state machine, which keeps track of which frame type is currently receiving.

If the CRC is correct the sequence number is checked against the expected value.

A Data frame and Broadcast frame buffer is used to temporally store one frame until the CRC at the end is checked.

Lane initialization state machine

57

State machine now described using only 11 states instead of the original 19 states.– Error recovery state machine is removed as its

functionality is already covered by the retry layer

Lane is disconnected when the lane receive error counter overflows – This indicates that the BER is too high. – BER is measured by decreasing the error counter every N

words (i.e. leaky bucket algorithm)

Functionality is the same as the previous version.– Supports AutoStart, inverted RX polarity, Standby and

LossOfSignal or receive error overflow indication.

Implementation requires less than half of the original hardware resources.

58NewRXERR = RXERR AND Previous Word NOT RXERRA Timeout error causes a transition to the ClearLine state.No Signal at receiver in any state causes a transition to the ClearLine state.

>8 RXERR ORUpper Layer Error

Active

Rx’edRCLR

FarEndRecoveringSend 1xRACK

NearEndRecoveringSend 9xRCLR

Rx’ed RCLR

RXERR

Sent1xRACKAND NotRx’edRCLR

NewRXERR

Sent9xRCLRAND Rx’edRACK

StartRecoveryStart Timeout Timer

AutoStartStart

Start Timeout TimerSend IDLE

AutoStartPolarityInvert Rx Polarity

Rx’ed 2xiIDLE ORRx’ed 2xiINIT

Rx’ed2xINIT

Rx’ed2xiIDLE

Rx’ed2xIDLE

StartPolarityInvert Rx Polarity

SEND IDLE

Lane_Start

FarEndStartedStart Timeout Timer

Send IDLE

Rx’ed2xIDLE

NearEndStartedSend INIT

Errors in the Receive Synchronisation state machine, which result in an RXERR control word are ignored.Eight consecutive RXERR control words in any state except Start and AutoStart cause a transition to the ClearLine state.A Timeout error in any state except the AutoStart states causes a transition to the ClearLine state.No Signal at receiver in any state except the Start and AutoStart states causes a transition to the ClearLine state.

Lane_StartAutoStart AND/Lane_Start

Active

/Lane_Start AND/AutoStart

WaitStart

/Lane_StartAND /AutoStart

BothEndsStartedSend IACK

Rx’ed2xIDLE

Rx’ed2xINIT

Rx’ed2xINIT

Rx’ed2xIDLE

HalfConnectedSend 16xIACK

Rx’ed2xIACK

Sent 16xIACKRx’ed2xIACKANDSent16xIACK

Rx’ed2xINIT

WaitStartDisable TX, RX, PLL

ColdResetDisable TX, RX, PLLClear Configuration

Recover Error

Initialise

Warm_Reset

Initialised

ActiveConnected

PrepareStandbySend 32x STANDBY

LossOfSignalSend 32x

LOST_SIGNAL

No Signal

Cold_Reset

Recovered

ClearLine ClearLine

InitialisationError

ClearLineDisable TX, RX, PLL

After 2μs

Timeout ORNo Signal

>8 RXERR OR Rx’ed RCLR ORUpper Layer Error

No Signal means no signal detected at receiver inputs.Initialisation errors are listed in Figure 5-9.

Rx’edLOST_SIGNALOR Rx’edSTANDBY

Lane_StartOR AutoStart



OLD state machine

WaitDisable TX

ClearLineDisable TX, RX, PLL

InvertRxPolaritySend INIT1s

StartedStart Timeout Timer

Send INIT1s

Warm_Reset

ConnectingSend INIT2s

Cold_Reset

DisabledDisable TX, RX, PLL

After 2μs

No Signal means no signal detected at receiver inputs.

Rx’ed 3x INIT1sOR Rx’ed 3x INIT2s

Lane_StartOR AutoStart

NOT Lane_Start ANDNOT AutoStart

ColdResetDisable TX, RX, PLLClear Configuration

Lane_StartOR

NOT No_SignalRx’ed 3x i_INIT1sOR Rx’ed 3x i_INIT2s


ConnectedSend INIT3s


Active

Rx’ed 3x INIT3s

PrepareStandbySend 32x STANDBY

LossOfSignalSend 32x LOS

No_Signal ORRX_ERROR counter overflow

NOT Lane_Start ANDNOT AutoStart

- No Signal in states: InvertRxPolarity, Connecting, Connected

- Timer Timeout in states:Started, InvertRxPolarity, Connecting,Connected

- Rx’ed 8x LOS OR Rx’ed 8x STANDBY in any state

Simplified state machine

Typical initialization sequence

1. Disabled– Leave state when lane enabled

2. Wait– Leave state when in Start mode or signal is received.

3. Started– Sends INIT1s to start connection– Leave state when INIT1 or INIT2 received

4. Connecting– Sends INIT2s to indicate that it is receiving words.– Leave state when INIT2 or INIT3 received

5. Connected– Sends INIT3s to exchange connection parameters– Leave state when INIT3 received

6. Active– Sends user data– Leave state when in either end an errors occurs or is

disabled.59

60

Active Active

Started

Connecting

Started

Connecting

Connected Connected

Link Initialisation - Handshaking

Robust control words encoding A control word begins with a comma

– Comma symbol K28.7 is used so that a single bit flip error in a data word can not convert it into a control word.

Second character indicates type of control word. – They are selected to have polarity so any single bit flip

occurred before will produce a 8B10B disparity error.

– They are selected to maximize the hamming distance (number of different bits) between them, so more than three bit flips are required to convert one valid character into another valid one. The hamming distance is 4.

61

Medium Access Control and QoS rules A Virtual Channel can send a data frame:

– If there is user data in the input buffer– If there is space at the destination– If It is scheduled to send data in the current TimeSlot.

The Virtual Channel (VC) with higher precedence will be selected.Precedence = Priority Precedence + BW credit– Priority precedence depends on the priority level of the

VC.– BW credit depends on the amount of data sent respect

to the reserved bandwidth of the VC.– BW credit only matters on VCs with same priority

Indicate to the user if a VC is using too much bandwidth or it is idle more than expected.62

QoS schemes supported

Deterministic scheduling scheme– All VCs scheduled at different timeslots.

Simple priority scheme– Each VC is set to a different priority levels

Simple Bandwidth allocation– All VCs set to same priority level

Different priorities with bandwidth allocation – Bandwidth arbitration between multiple VCs for payload data– Command and Control set to use higher priority VCs

Different priorities with bandwidth allocation and scheduling– Some slots are reserved for VCs with deterministic

requirements.

63

SpaceFibre versus Rapid IO

Rapid IO (Xilinx srio_ds696)

SpaceFibre

Automatic retry Yes Yes

Power management Yes Yes

Scrambling Yes Yes

Worst case retry reaction time

Timeout value Delay of the line

Virtual Channels 1 8

Flow control Yes Yes

Priorities Yes (3 levels) Yes (8 levels)

BW allocation No Yes

Scheduling No Yes

64

SpaceFibre smaller than RAPID IO

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

65

Rapid IO Total SpaceFibre CODEC (1 VC) SpaceWire RMAP+CODECLUTs 5400 2530 1667FF 5250 1825 1329

0

1000

2000

3000

4000

5000

6000C

ompl

exity

Rapid IO vs SpaceFibre vs SpW & RMAP

LUTs

FF

SpaceFibre cost of multiple VCs

66

SpaceFibre CODEC (1 VC) SpaceFibre CODEC (8 VC)LUTs 2530 4850FF 1825 3470

0

1000

2000

3000

4000

5000

6000C

ompl

exity

Complexity: 1 VC vs 8 VC

LUTs

FF

SpaceFibre Next Steps

67

SpaceFibre FDIR FDIR

– Fault detection Parity/disparity Invalid 8B/10B codes Enhance Hamming distance 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 reporting68

SpaceFibre Next Steps Provide TKL2711 interface to CODEC Complete Multi-Lane layer specification Include Multi-Lane layer in CODEC Complete SpaceFibre specification Add Network layer

69

steve parkes , chris mcclements -...

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