SIST EN 16603-50-11:2020

SLOVENSKI STANDARD
01-november-2020
Vesoljska tehnika - SpaceFibre - Zelo hiter serijski vmesnik
Space engineernig - SpaceFibre - Very high-speed serial link
Raumfahrttechnik - SpaceFibre - Serielle Verbindung mit sehr hoher Geschwindigkeit
Ingénierie spatiale - SpaceFibre - Liaison série très haut débit
Ta slovenski standard je istoveten z: EN 16603-50-11:2020
ICS:
49.140 Vesoljski sistemi in operacije Space systems and
operations
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 16603-50-11
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2020
ICS 49.140
English version
Space engineernig - SpaceFibre - Very high-speed serial
link
Ingénierie spatiale - SpaceFibre - Liaison série très Raumfahrttechnik - SpaceFibre - Teil 50-11: Sehr
haut débit schnelle serielle Schnittstelle
This European Standard was approved by CEN on 3 May 2020.

CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical
references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to
any CEN and CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN and CENELEC member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium,
Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

CEN-CENELEC Management Centre:
Rue de la Science 23, B-1040 Brussels
© 2020 CEN/CENELEC All rights of exploitation in any form and by any means Ref. No. EN 16603-50-11:2020 E
reserved worldwide for CEN national Members and for
CENELEC Members.
Table of contents
European Foreword . 9
1 Scope . 10
2 Normative references . 11
3 Terms, definitions and abbreviated terms . 13
3.1 Terms defined in other standards . 13
3.2 Terms specific to the present standard . 13
3.3 Abbreviated terms. 26
3.4 Conventions. 29
3.4.1 Numbers . 29
3.4.2 Multiplication . 29
3.4.3 Differential signals . 29
3.4.4 Order of sending bits in symbols . 29
3.4.5 Graphical representation of packets . 30
3.4.6 State diagram notation . 30
3.4.7 UML diagram notation . 31
3.4.8 D/K notation for 8B/10B characters . 32
3.5 Nomenclature . 32
4 Principles . 34
4.1 SpaceFibre purpose . 34
4.2 SpaceFibre overview . 35
5 Requirements . 37
5.1 Overview . 37
5.2 Protocol stack and interface architecture . 37
5.2.1 General . 37
5.2.2 Network layer . 39
5.2.3 Data Link layer . 39
5.2.4 Multi-Lane layer . 40
5.2.5 Lane layer . 40
5.2.6 Physical layer . 41
5.2.7 Management Information Base . 41
5.3 Formats . 41
5.3.1 Control words and encoding/decoding . 41
5.3.2 8B/10B encode/decode . 42
5.3.3 Lane control words . 44
5.3.4 Multi-Lane control words . 51
5.3.5 Data Link control words . 53
5.3.6 Receive error indication control word (RXERR) . 62
5.3.7 Characters . 63
5.3.8 Frames . 66
5.3.9 Packets . 70
5.3.10 Control word and frame precedence . 70
5.3.11 K-code summary . 73
5.3.12 Control word symbol summary . 73
5.4 Physical layer . 74
5.4.1 Physical layer responsibilities . 74
5.4.2 Serialisation . 75
5.4.3 Electrical physical layer . 77
5.4.4 Electrical medium . 88
5.4.5 Fibre optic physical layer . 97
5.4.6 Fibre optic medium . 103
5.5 Lane layer . 112
5.5.1 Lane layer responsibilities . 112
5.5.2 Lane initialisation and standby management . 114
5.5.3 Data signalling rate compensation . 126
5.5.4 IDLE words . 126
5.5.5 Parallel loopback . 127
5.5.6 Symbol synchronisation . 127
5.5.7 Word synchronisation . 127
5.5.8 Receive synchronisation state machine . 129
5.6 Multi-Lane layer . 131
5.6.1 Multi-Lane layer responsibilities . 131
5.6.2 Multi-Lane link . 132
5.6.3 Multi-Lane bypass . 133
5.6.4 Multi-Lane distribution . 133
5.6.5 Multi-Lane concentration . 137
5.6.6 Lane Alignment . 137
5.6.7 Alignment state diagram . 141
5.6.8 Asymmetric links . 144
5.6.9 Initialisation of unidirectional lanes . 145
5.6.10 Hot redundant lanes . 146
5.7 Data Link layer . 149
5.7.1 Data Link layer responsibilities . 149
5.7.2 Virtual channels . 151
5.7.3 Flow control. 153
5.7.4 Medium access controller. 155
5.7.5 Broadcast flow control . 163
5.7.6 Framing . 164
5.7.7 Error recovery . 177
5.7.8 Data word identification state machine . 184
5.7.9 Link Reset state machine . 189
5.7.10 Link reset . 192
5.8 Network layer . 194
5.8.1 Network layer responsibilities . 194
5.8.2 SpaceFibre network . 195
5.8.3 Virtual networks . 196
5.8.4 Links . 199
5.8.5 Packet format . 199
5.8.6 Sending a packet . 200
5.8.7 Receiving a packet . 200
5.8.8 Routing switch . 201
5.8.9 Packet addressing. 207
5.8.10 Group adaptive routing . 209
5.8.11 Packet multicast . 209
5.8.12 Broadcast messages . 210
5.8.13 SpaceFibre nodes . 212
5.8.14 SpaceFibre units . 213
5.9 Management Information Base . 214
5.9.1 Management Information Base responsibilities . 214
5.9.2 Network management . 214
5.9.3 Configuration parameters . 215
5.9.4 Status parameters . 219
6 Service interfaces . 221
6.1 Overview . 221
6.2 Network layer service interface . 221
6.2.1 Network layer services . 221
6.2.2 Packet Transfer service . 221
6.2.3 Broadcast message service . 223
6.3 Data Link layer service interface . 224
6.3.1 Data Link layer services . 224
6.3.2 Virtual Channel service . 224
6.3.3 Broadcast message service . 225
6.3.4 Schedule synchronisation service . 226
6.4 Physical layer service interfaces . 227
6.4.1 Physical layer services . 227
6.4.2 Transfer symbols service . 227
6.4.3 Control service . 228
6.5 Management Information Base service interface . 230
6.5.1 Management Information Base services . 230
6.5.2 Link Management service . 230
Bibliography . 232

Figures
Figure 3-1: Convention for first bit to be sent . 29
Figure 3-2: Graphical packet notation . 30
Figure 3-3: State diagram style . 30
Figure 3-4: UML notation . 31
Figure 3-5: D/K notation for 8B/10B characters . 32
Figure 4-1: Overview of SpaceFibre protocol stack . 35
Figure 5-1: SpaceFibre protocol stack - single-lane . 38
Figure 5-2: SpaceFibre protocol stack - multi-lane . 39
Figure 5-3: Fills at the end of packets . 65
Figure 5-4: Fills at the start and end of a packet . 66
Figure 5-5: Data frame format for a single lane . 66
Figure 5-6: Idle frame format . 67
Figure 5-7: Broadcast frame format . 68
Figure 5-8: Interfaces to the Physical layer . 75
Figure 5-9: One direction of electrical Physical layer, showing series capacitors,
discharge resistors, and different grounds . 77
Figure 5-10: Serial output signals . 79
Figure 5-11: Serial output test circuit . 80
Figure 5-12: Serial eye pattern mask . 80
Figure 5-13: Serial input signals . 86
Figure 5-14: Type-A electrical flight cable assembly . 89
Figure 5-15: Type-A electrical flight connector saver . 90
Figure 5-16: Type-C electrical EGSE cable assembly . 93
Figure 5-17: Type-C electrical EGSE to flight adaptor cable assembly . 94
Figure 5-18: One direction of fibre optic Physical layer, showing fibre optic transmitter,
receiver, connectors and cable . 97
Figure 5-19: One direction of active optical cable type of fibre optic Physical layer . 97
Figure 5-20: Electro-optical eye pattern for 1 Gbit/s to 5 Gbit/s transmitters . 99
Figure 5-21: Electro-optical eye pattern for 1 Gbit/s to 10 Gbit/s transmitters . 100
Figure 5-22: SpaceFibre lane comprising two Type-A fibre optic flight cable assemblies,
one for each direction . 105
Figure 5-23: Type-B fibre optic flight cable assembly with one lane . 107
Figure 5-24: Type-B fibre optic flight cable assembly with several lanes . 108
Figure 5-25: Type-B fibre optic flight cable assembly for an asymmetric link . 108
Figure 5-26: Type-C flight active optical cable assembly . 111
Figure 5-27: Interfaces to the Lane layer for a single lane link . 113
Figure 5-28: Interfaces to the Lane layer for a multi-lane link. 114
Figure 5-29: Lane initialisation state machine . 115
Figure 5-30: Receive synchronisation state machine . 129
Figure 5-31: Interfaces to Multi-Lane layer . 132
Figure 5-32: Multi-Lane link with different number of lanes at each end . 133
Figure 5-33: Words forming a row across a multi-lane link . 134
Figure 5-34: Spreading data across a multi-lane link . 135
Figure 5-35: PAD control words in a multi-lane link . 135
Figure 5-36: Row alignment across a multi-lane link . 140
Figure 5-37: Alignment state machine . 141
Figure 5-38: Multi-Lane link incorporating some unidirectional lanes . 144
Figure 5-39: Interfaces to the Data Link layer for a single lane link . 150
Figure 5-40: Interfaces to the Data Link layer for a multi-lane link . 150
Figure 5-41: Scrambler / de-scrambler . 165
Figure 5-42: Example of scrambling of a short data frame . 166
Figure 5-43: Effect of scrambling on an idle frame . 167
Figure 5-44: Examples of CRC calculation for a short data frame . 172
Figure 5-45: Illustration of bit ordering during 16-bit CRC calculation . 172
Figure 5-46: Examples of CRC calculation for a broadcast frame and FCT . 175
Figure 5-47: Illustration of bit ordering during 8-bit CRC calculation . 176
Figure 5-48: Receive Error state machine . 182
Figure 5-49: Data Word Identification state machine . 185
Figure 5-50: Link Reset state machine . 190
Figure 5-51: Interfaces to the Network layer . 194
Figure 5-52: Components of a SpaceFibre network . 195
Figure 5-53: Relationships of a SpaceFibre virtual network . 197
Figure 5-54: SpaceFibre packet format . 199
Figure 5-55: Components of a SpaceFibre routing switch . 202
Figure 5-56: Components and specialisations of a SpaceFibre node . 212
Figure 5-57: Components and specialisations of a SpaceFibre unit . 214

Tables
Table 5-1: 5B/6B encoding . 43
Table 5-2: 3B/4B encoding . 44
Table 5-3: Lane control words . 44
Table 5-4: Multi-Lane control words. 51
Table 5-5: Data framing control words . 53
Table 5-6: Flow control word . 58
Table 5-7: Error recovery control words . 60
Table 5-8: Receive error indication control word . 63
Table 5-9: SpaceFibre N-Char Symbols . 64
Table 5-10: Fill control character symbol . 64
Table 5-11: Meaning of K-codes . 73
Table 5-12: Meaning of control word symbols . 73
Table 5-13: Serial output interface . 77
Table 5-14: Serial eye pattern mask intervals 1 Gbit/s to 3,125 Gbit/s . 81
Table 5-15: Serial eye pattern mask intervals above 3,125 Gbit/s to 6,25 Gbit/s . 81
Table 5-16: Coefficient α for different values of BER . 82
Table 5-17: Driver and receiver characteristics 1 Gbit/s to 3,125 Gbit/s . 83
Table 5-18: Driver and receiver characteristics above 3,125 Gbit/s to 6,25 Gbit/s . 84
Table 5-19: Serial input interface . 85
Table 5-20: Type-A electrical flight cable assembly connector contact terminations . 89
Table 5-21: Type-A electrical flight connector saver connector contact terminations . 89
Table 5-22: Type-B electrical flight cable assembly connector contact terminations . 92
Table 5-23: Type-C electrical EGSE cable assembly connector contact terminations . 93
Table 5-24: Type-C electrical EGSE to flight adaptor cable assembly connector contact
terminations . 94
Table 5-25: Type-D electrical EGSE cable assembly connector contact terminations . 96
Table 5-26: Electro-optical characteristics for 1 Gbit/s to 5 Gbit/s transmitters . 100
Table 5-27: Electro-optical characteristics for 1 Gbit/s to 10 Gbit/s transmitters . 101
Table 5-28: Electro-optical characteristics for 1 Gbit/s to 5 Gbit/s receivers . 102
Table 5-29: Electro-optical characteristics for 1 Gbit/s to 10 Gbit/s receivers . 103
Table 5-30: Connection of SpaceFibre lane using Type-A flight fibre optic cable
assemblies . 105
Table 5-31: Type-B flight fibre optic cable assembly connector contact terminations for
each SpaceFibre lane . 107
Table 5-32: Type-C flight active optical cable connector terminations for each
SpaceFibre lane . 109
Table 5-33: Type-C flight active optical cable assembly connector contact terminations
for each SpaceFibre lane . 110
Table 5-34: Precedence for different qualities of service . 158
Table 5-35: Routing switch addresses . 204
Table 5-36: SpaceFibre configuration parameters . 216
Table 5-37: SpaceFibre status parameters . 219

European Foreword
This document (EN 16603-50-11:2020) has been prepared by Technical
Committee CEN-CENELEC/TC 5 “Space”, the secretariat of which is held by
DIN.
This document (EN 16603-50-11:2020) originates from ECSS-E-ST-50-11C.
This European Standard shall be given the status of a national standard, either
by publication of an identical text or by endorsement, at the latest by March
2021, and conflicting national standards shall be withdrawn at the latest by
March 2021.
Attention is drawn to the possibility that some of the elements of this document
may be the subject of patent rights. CEN [and/or CENELEC] shall not be held
responsible for identifying any or all such patent rights.
This document has been prepared under a standardization request given to
CEN by the European Commission and the European Free Trade Association.
This document has been developed to cover specifically space systems and has
therefore precedence over any EN covering the same scope but with a wider
domain of applicability (e.g. : aerospace).
According to the CEN-CENELEC Internal Regulations, the national standards
organizations of the following countries are bound to implement this European
Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
Scope
SpaceFibre is a very high-speed serial link and network technology, designed
specifically for use on board spacecraft. SpaceFibre is able to operate over fibre-
optic and electrical cable and supports data rates of up to 5 Gbit/s (6,25 Gbit/s
data signalling rate). It complements the capabilities of the widely used
SpaceWire on-board networking standard: improving the data rate by a factor
of 10, reducing the cable mass and providing galvanic isolation. Multi-laning
improves the data rate further to well over 20 Gbit/s.
SpaceFibre provides a coherent quality of service mechanism able to support
bandwidth reserved, scheduled and priority-based qualities of service. It
substantially improves the fault detection, isolation and recovery (FDIR)
capability compared to SpaceWire.
SpaceFibre aims to support high data-rate payloads, for example synthetic
aperture radar and hyper-spectral optical instruments. It provides robust, long
distance communications for launcher applications and supports avionics
applications with deterministic delivery constraints through the use of virtual
channels. SpaceFibre enables a common on-board infrastructure to be used
across many different mission applications resulting in cost reduction and
design reusability. SpaceFibre uses a packet format which is the same as
SpaceWire enabling simple connection between existing SpaceWire equipment
and high-speed SpaceFibre links and networks. Applications developed for
SpaceWire can be readily transferred to SpaceFibre.
The SpaceFibre standard specifies the interfaces to the user application and to
the physical medium. Intermediate interfaces between protocol layers are also
specified. The functions that a SpaceFibre interface has to implement are
specified. Connector and cable characteristics for SpaceFibre optical and copper
implementations are also specified.
This standard may be tailored for the specific characteristics and constraints of a
space project in conformance with ECSS-S-ST-00.
Normative references
The following normative documents contain provisions which, through
reference in this text, constitute provisions of this ECSS Standard. For dated
references, subsequent amendments to, or revision of any of these publications
do not apply. However, parties to agreements based on this ECSS Standard are
encouraged to investigate the possibility of applying the more recent editions of
the normative documents indicated below. For undated references, the latest
edition of the publication referred to applies.

EN reference Reference in text Title
EN 16601-00-01 ECSS-S-ST-00-01 ECSS system - Glossary of terms
EN 16603-50-52 ECSS-E-ST-50-52 Space engineering - SpaceWire – Remote memory
access protocol
EN 16602-70-02 ECSS-Q-ST-70-02 Space product assurance - Thermal vacuum
outgassing test for the screening of space materials
EN 16602-70-21 ECSS-Q-ST-70-21 Space product assurance - Flammability testing for the
screening of space materials
EN 16602-70-29 ECSS-Q-ST-70-29 Space product assurance - Determination of offgassing
products from materials and assembled articles to be
used in a manned space vehicle crew compartment
ESCC 2263420:2017 Evaluation Test programme for optical fibre cable
assemblies, ESCC Basic Specification, issue 1, June
ESCC 3401/090:2018 High Data Rate Connectors Savers, Plugs based on
type AxoMach, ESCC Detail Specification, issue 1,
ESCC 3409:2018 High Data Rate Cable Assemblies, ESCC Generic
Specification, issue 1, 2018
ESCC 3409/001:2018 High Data Rate Harnesses based on type AxoMach,
ESCC Detail Specification, issue 1, 2018
ESCC 3420:2017 Optical Fibre Cable Assemblies with Single Fibre
Ferrules, ESCC Generic Specification, issue 1, June
ESCC 3420/001:2017 Optical Fibre Cable Assemblies with Single Fibre
Ferrules, ESCC Detail Specification, issue 1, June 2017
EN reference Reference in text Title
IEC 60793-2-10:2015 Optical fibres - Part 2-10: Product specifications -
Sectional specification for category A1 multimode
fibres, IEC, 2015
IEC 61754-5:2005 Fibre optic connector interfaces - Part 5: Type MT
connector family, IEC, 2005
IEC 61755-3-31:2015 Fibre optic interconnecting devices and passive
components - Connector optical interfaces - Part 3-31:
Connector parameters of non-dispersion shifted single
mode physically contacting fibres - Angled
polyphenylene sulphide rectangular ferrules
IEC 61755-3-32:2015 Fibre optic interconnecting devices and passive
components - Connector optical interfaces - Part 3-32:
Connector parameters of non-dispersion shifted single
mode physically contacting fibres - Angled thermoset
epoxy rectangular ferrules
IEEE 802.3:2012 IEEE Standard for Ethernet, IEEE Standards
Association, 28 December 2012
MIL-PRF-49291, Performance Specification, Fiber, Optical, (Metric)
Revision D, General Specification
Amendment 1,
20 November 2014
Serial ATA Revision Serial ATA Revision 3.0, clause 6.6.1, Serial ATA
3.0:2009 International Organization, June 2, 2009, Gold
Revision
Terms, definitions and abbreviated terms
3.1 Terms defined in other standards
a. For the purpose of this Standard, the terms and definitions from ECSS-S-
ST-00-01 apply.
3.2 Terms specific to the present standard
3.2.1 active lane
unidirectional lane or bi-directional lane which is in the Active state
3.2.2 asymmetric link
multi-lane link that includes one or more unidirectional lanes
3.2.3 available bandwidth
number of data words or control words sent since the bandwidth credit was
last updated
3.2.4 bandwidth credit
amount of link bandwidth that a virtual channel has accumulated
3.2.5 bandwidth credit limit
maximum amount of positive or negative bandwidth credit that a virtual
channel is allowed to accumulate
3.2.6 bandwidth utilisation
measure of how much bandwidth allocated to a virtual channel has been used
recently, allowing for loss of measured use of bandwidth when either the
positive or negative bandwidth credit limit is reached
3.2.7 bi-directional lane
active lane or inactive lane which has the TX_EN and RX_EN configuration
bits asserted at both ends of the link, so that when active it can send
information in both directions of the link
3.2.8 bit error rate
ratio of the number of bits received in error to the total number of bits sent
across a link
3.2.9 bit interval
duration of a bit travelling over a serial interface
3.2.10 broadcast frame
broadcast message which has been encapsulated using an SBF at the front of
the broadcast message and an EBF at the end of the broadcast message
3.2.11 broadcast message
eight bytes of application data sent to every node on the network, along with
an eight-bit broadcast type, which determines the meaning of the application
data
3.2.12 byte
eight bits
3.2.13 cargo
information for transferring from a source to a destination which is
encapsulated in a packet
3.2.14 character
data character or control character
3.2.15 coding
act of translating a set of bits into another set of bits which are more appropriate
for transmitting across a medium
3.2.16 comma
K28.5 or K28.7 control symbol
3.2.17 configuration port
port in a routing switch or node that gives access to a configuration node
3.2.18 configuration node
type of node whose purpose is to configure the routing switch that it is part of
3.2.19 continuous mode
mode of virtual channel operation which ignores flow control so that data can
always be accepted from the Network layer but if the virtual channel buffer is
full that data will be discarded
3.2.20 control character
character containing 8-bits of control information
3.2.21 control symbol
K-symbol
3.2.22 control word
word used for control of the SpaceFibre protocol comprising a comma, or the K-
code of an EBF, EDF, FCT or RXERR, followed by three data characters or Fills
3.2.23 current running disparity
accumulated disparity of a bit stream from when it started to the present
moment in time
3.2.24 data character
character containing 8-bits of data information
3.2.25 data frame
segment of N-Chars and Fills from one or more packets which have been
encapsulated using an SDF, for each lane, at the front of the segment and an
EDF, for each lane, at the end of that segment
3.2.26 Data Link layer
protocol layer which is responsible for transferring packets and broadcast
messages over the link, for the quality of service over the link, and for recovery
from errors on the link
3.2.27 Data Link layer control word
ACK, NACK, FULL, RETRY, SDF, EDF, SBF, EBF, SIF, or FCT control word
3.2.28 data rate
rate at which the application data is transferred across a link
3.2.29 data-receiving lane
active, receive enabled lane, which is connected to a data-sending lane so that
it can receive Data Link layer words
NOTE Receive enabled lane means RX_EN asserted at
the near-end of the link.
3.2.30 data segment
group of up to N×64 sequential data words from one or more packets, where N
is an integer less than or equal to the "maximum number of data-sending lanes"
parameter
NOTE The term ”segment” is synonymous.
3.2.31 data-sending lane
active, transmit enabled lane which when provided with Data Link layer
words, sends them to the data-receiving lane at the far-end of the link
NOTE Transmit enabled lane means TX_EN asserted
at the near-end of the link.
3.2.32 data signalling rate
rate at which the bits constituting control and data symbols are transferred
across a link
3.2.33 data symbol
D-symbol
3.2.34 data word
word of data comprising four SpaceFibre N-Chars or Fill characters
3.2.35 decoding
act of translating an encoded set of bits back into the original set of bits prior to
encoding
3.2.36 device
node or routing switch
3.2.37 de­serialisation
transformation of a serial bit stream into parallel data
3.2.38 deserialiser
circuit that converts a sequence of bits from a serial bit stream into parallel data
3.2.39 destination
end-point that a packet is being sent to
3.2.40 destination address
route to be taken by a packet in moving from source to destination or an
identifier specifying the destination
3.2.41 destination node
node that is the destination of one or more SpaceFibre packets
3.2.42 disparity
number of ones in a bit stream minus the number of zeros in that bit stream
3.2.43 driver
electronic circuit that transmits signals across a particular transmission
medium
3.2.44 D-code
9-bit representation of an 8-bit data character which is transmitted using 8B/10B
encoding comprising a D/K flag, which is set to zero, and the 8-bit data
character
3.2.45 D-symbol
10-bit symbol formed by 8B/10B encoding of a D-code
3.2.46 D/K flag
1-bit flag forming part of a D-code or K-code, which when set to zero indicates
the code is a D-code or when set to one, is a K-code
3.2.47 end of packet marker (EOP)
N-Char which indicates the end of a packet
3.2.48 end-point
interface between the network and a host system providing a single port into
the network
3.2.49 error end of packet marker (EEP)
N-Char which indicates the end of a packet in which an error has occurred
3.2.50 FarEndActive
indication that the far-end of a lane is in the Active state, the indication being
sent in an ACTIVE control word over any lane forming part of a multi-lane
link
3.2.51 Fill
character used in a PAD control word or used for word alignment which can
occur in a data frame between the end of one packet and the beginning of the
next one, or after reset, before the beginning of the first packet
3.2.52 flow control token (FCT)
control word used to manage the flow of data across a link and which is
exchanged for M×64 data words, where M is an integer in the range 1 to 8
3.2.53 frame
data frame, broadcast frame or idle frame
3.2.54 header deletion
removal of the leading data character of a packet by a routing switch after it
has been used to determine the output port that the packet is forwarded to and
before the packet is switched to that output port, that leading data character
being replaced by a Fill
3.2.55 host interface
interface to a host system
3.2.56 host system
system that is connected to a SpaceFibre network via an end-point and which
uses the services of that SpaceFibre network
3.2.57 hot redundant lane
active, transmit enabled lane, which is not a data-sending lane and which is
ready to replace a failed data-sending lane
NOTE Transmit enabled lane means TX_EN asserted
at the near-end of the link.
3.2.58 idle frame
frame of pseudo-random data which is sent when there are no data frames or
broadcast frames to be sent
3.2.59 inactive lane
unidirectional lane or bi-directional lane which is N
...