SIST EN IEC 62680-4-1:2023

SLOVENSKI STANDARD
01-marec-2023
Vmesniki univerzalnega serijskega vodila za prenos podatkov in napajanje - 4-1.
del: Specifikacija univerzalnega serijskega vodila 4 (tm) (IEC 62680-4-1:2022)
Universal Serial Bus interfaces for data and power - Part 4-1: Universal Serial Bus 4 (tm)
Specification (IEC 62680-4-1:2022)
Schnittstellen des Universellen Seriellen Busses für Daten und Energie - Teil 4-1:
Universeller Serieller Bus 4 (TM) Spezifikation (IEC 62680-4-1:2022)
Interfaces de bus série universel (USB) pour les données et l'alimentation électrique -
Partie 4-1: Spécification du bus série universel 4 (tm) (IEC 62680-4-1:2022)
Ta slovenski standard je istoveten z: EN IEC 62680-4-1:2022
ICS:
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62680-4-1

NORME EUROPÉENNE
EUROPÄISCHE NORM November 2022
ICS 29.200; 33.120.20; 35.200
English Version
Universal Serial Bus interfaces for data and power - Part 4-1:
Universal Serial Bus 4 (tm) Specification
(IEC 62680-4-1:2022)
Interfaces de bus série universel (USB) pour les données et Schnittstellen des Universellen Seriellen Busses für Daten
l'alimentation électrique - Partie 4-1: Spécification du bus und Energie - Teil 4-1: Universeller Serieller Bus 4 (TM)
série universel 4 (tm) Spezifikation
(IEC 62680-4-1:2022) (IEC 62680-4-1:2022)
This European Standard was approved by CENELEC on 2022-11-23. 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 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62680-4-1:2022 E

European foreword
The text of document 100/3754/CDV, future edition 1 of IEC 62680-4-1, prepared by IEC/TC 100
"Audio, video and multimedia systems and equipment" was submitted to the IEC-CENELEC parallel
vote and approved by CENELEC as EN IEC 62680-4-1:2022.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2023-08-23
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2025-11-23
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 62680-4-1:2022 was approved by CENELEC as a
European Standard without any modification.

IEC 62680-4-1 ®
Edition 1.0 2022-10
INTERNATIONAL
STANDARD
colour
inside
Universal Serial Bus interfaces for data and power –

Part 4-1: Universal Serial Bus 4 ™ Specification

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.200; 33.120.20; 35.200 ISBN 978-2-8322-5816-3

- 2 - IEC 62680-4-1:2022
© USB-IF 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
UNIVERSAL SERIAL BUS INTERFACES FOR DATA AND POWER

Part 4-1: Universal Serial Bus 4™ Specification

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical
Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations
liaising with the IEC also participate in this preparation. IEC collaborates closely with the International
Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 62680-4-1 has been prepared by technical area 18: Multimedia
home systems and applications for end-user networks, of IEC technical committee 100: Audio,
video and multimedia systems and equipment.
The text of this standard was prepared by the USB Implementers Forum (USB-IF). The
structure and editorial rules used in this publication reflect the practice of the organization
which submitted it.
The text of this International Standard is based on the following documents:
Draft Report on voting
100/3754/CDV 100/3813/RVC
IEC 62680-4-1:2022 - 3 -
© USB-IF 2021
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

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© USB-IF 2021
INTRODUCTION
The IEC 62680 series is based on a series of specifications that were originally developed by the USB
Implementers Forum (USB-IF). These specifications were submitted to the IEC under the auspices of
a special agreement between the IEC and the USB-IF.
This standard is the USB-IF publication, USB4™ Specification, Version 1.0 with Errata and ECN
through May 19, 2021.
The USB Implementers Forum, Inc.(USB-IF) is a non-profit corporation founded by the group of
companies that developed the Universal Serial Bus specification. The USB-IF was formed to provide
a support organization and forum for the advancement and adoption of Universal Serial Bus
technology. The Forum facilitates the development of high-quality compatible USB peripherals
(devices), and promotes the benefits of USB and the quality of products that have passed compliance
testing.
ANY USB SPECIFICATIONS ARE PROVIDED TO YOU "AS IS, "WITH NO WARRANTIES
WHATSOEVER, INCLUDING ANY WARRANTY OF MERCHANTABILITY, NON-INFRINGEMENT,
OR FITNESS FOR ANY PARTICULAR PURPOSE. THE USB IMPLEMENTERS FORUM AND THE
AUTHORS OF ANY USB SPECIFICATIONS DISCLAIM ALL LIABILITY, INCLUDING LIABILITY
FOR INFRINGEMENT OF ANY PROPRIETARY RIGHTS, RELATING TO USE OR
IMPLEMENTATION OR INFORMATION IN THIS SPECIFICAITON.
THE PROVISION OF ANY USB SPECIFICATIONS TO YOU DOES NOT PROVIDE YOU WITH ANY
LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL
PROPERTY RIGHTS.
Entering into USB Adopters Agreements may, however, allow a signing company to participate in a
reciprocal, RAND-Z licensing arrangement for compliant products. For more information, please see:
https://www.usb.org/documents
IEC DOES NOT TAKE ANY POSITION AS TO WHETHER IT IS ADVISABLE FOR YOU TO ENTER
INTO ANY USB ADOPTERS AGREEMENTS OR TO PARTICIPATE IN THE USB IMPLEMENTERS
FORUM.”
IEC 62680-4-1:2022 - 5 -
© USB-IF 2021
Universal Serial Bus 4 (USB4™)
Specification
Apple Inc.
HP Inc.
Intel Corporation
Microsoft Corporation
Renesas Corporation
STMicroelectronics
Texas Instruments
Version 1.0 with Errata and ECN through May 19, 2021

May 2021
- 6 - IEC 62680-4-1:2022
© USB-IF 2021
Release History
Version Comments Issue Date
1.0 First release August 2019
1.0 with Errata and ECN through Includes errata and ECN through May 4, June 2020
May 4, 2020 2020 as part of the specification text.
1.0 with Errata and ECN through Includes errata and ECN through October October 2020
October 15, 2020 15, 2020 as part of the specification text.
1.0 with Errata and ECN through Includes errata and ECN through May 19, May 2021
May 19, 2021 2021 as part of the specification text.

IEC 62680-4-1:2022 - 7 -
© USB-IF 2021
NOTE: Adopters may only use this USB specification to implement USB or third party functionality as
expressly described in this Specification; all other uses are prohibited.

LIMITED COPYRIGHT LICENSE: The Promoters grant a conditional copyright license under the
copyrights embodied in this USB Specification to use and reproduce the Specification for the sole
purpose of, and solely to the extent necessary for, evaluating whether to implement the
Specification in products that would comply with the specification. Without limiting the foregoing,
use of the Specification for the purpose of filing or modifying any patent application to target the
Specification or USB compliant products is not authorized. Except for this express copyright license,
no other rights or licenses are granted, including without limitation any patent licenses. In order to
obtain any additional intellectual property licenses or licensing commitments associated with the
Specification a party must execute the USB Adopters Agreement. NOTE: By using the Specification,
you accept these license terms on your own behalf and, in the case where you are doing this as an
employee, on behalf of your employer.

INTELLECTUAL PROPERTY DISCLAIMER
THIS SPECIFICATION IS PROVIDED TO YOU “AS IS” WITH NO WARRANTIES WHATSOEVER INCLUDING
ANY WARRANTY OF MERCHANTABILITY, NON-INFRINGEMENT, OR FITNESS FOR ANY PARTICULAR
PURPOSE. THE AUTHORS OF THIS SPECIFICATION DISCLAIM ALL LIABILITY FOR INFRINGEMENT OF
ANY PROPRIETARY RIGHTS, RELATING TO THE USE OR IMPLEMENTATION OF INFORMATION IN THIS
SPECIFICATION. THE PROVISION OF THIS SPECIFICATION TO YOU DOES NOT PROVIDE YOU WITH
ANY LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY
RIGHTS.
Please send comments to techsup@usb.org.
For industry information, refer to the USB Implementers Forum web page at
http://www.usb.org.
USB Type-C®, USB-C®, USB 2.0 Type-C™, and USB4™ are trademarks of the Universal
Serial Bus Implementers Forum (USB-IF). DisplayPort™ is a trademark of VESA. All product
names are trademarks, registered trademarks, or service marks of their respective owners.
Thunderbolt™ is a trademark of Intel Corporation. You may only use the Thunderbolt™
trademark or logo in conjunction with products designed to this specification that complete
proper certification and executing a Thunderbolt™ trademark license – see usb.org/compliance
for further information
Corporation, Renesas Corporation, STMicroelectronics, and Texas Instruments).

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© USB-IF 2021
Acknowledgement of Technical Contribution
The authors of this specification would like to recognize the following people who participated
in the USB4 Specification technical work group.
Apple Inc. – Promoter Company Employees
Majd Abu Tayeh Nimrod Agmon Lior Aloni Brian Baek
Omer Bar-Lev Moshe Benyamini Gopu Bhaskar Carlos Calderon
David Conroy Bill Cornelius Scott Deandrea William Ferry
Amit Flanter Itay Franko Radia Gantous Alex Gerber
Mark Goikhman Nir Guetta Yair Hershkovitz Scott Jackson
Husam Khashiboun Alan Kobayashi Alexei Kosut Christine Krause
Dmitri Krichevsky Alex Lozovik Rachel Menes Shlomi Mor
Shlomi Museri Mona Omari Tal Ostro Arie Peled
Collin Pieper Idan Reller Reese Schreiber Oleg Schtofenmaher
Etan Shirron Ori Moshe Stern Jose Tierno Maxim Tsudik
Anatoly Uskach Jeff Wilcox Dan Wilson Ohad Zalcman
HP Inc. – Promoter Company Employees
Roger Benson Marcus Benzel Alan Berkema Kenneth Chan
Frank Chen Phil Chen Hosup Chung Glen Dower
Mark Lessman Nam Nguyen Roger Pearson Kenneth Smith
Chris Tabarez
Intel Corporation – Promoter Company Employees
Nausheen Ansari Noam Arzy Alexandre Audier Binata Bhattacharyya
Huimin Chen Hengju Cheng Salauddin Choudhury John Crouter
Maxim Dan Jhuda Dayan Yoni Dishon Eran Galil
Saranya Gopal Venkataramani Raul Gutierrez Michael Gouzenfeld
Gopalakrishnan
Mickey Gutman Benjamin Hacker Yaniv Hayat Uri Hermoni
Alon Horn Abdul Ismail Abhilash K V Ziv Kabiry
Vijaykumar Kadgi Vijay Kasturi Sergey Khaykin Lev Kolomiets
Vladislav Kopzon Efraim Kugman Edmond Lau Uriel Lemberger
Yun Ling Guobin Liu Balaji Manoharan Liran Manor
Uma Medepalli Assaf Mevorach Hezi Naaman Ohad Navon
Naod Negussie CheeLim Nge Leonid Plaks Duane Quiet
Rajaram Regupathy Reuven Rozic Oren Salomon Zeeshan Sarwar
Brad Saunders Leonid Shaposhnik Ehud Shoor Ari Sharon

IEC 62680-4-1:2022 - 9 -
© USB-IF 2021
Uri Soloveychik Einat Surijan Aviel Uzan Karthi Vadivelu
Alex Vekker Chen Vrubel Stephanie Wallick Tzewen Wang
Sarel Wechsler Ady Weiss Vitaly Zhivov Gal Yedidia
Vladimir Yudovich Aruni Nelson
Microsoft Corporation – Promoter Company Employees
Randy Aull Jim Belesiu Martin Borve Anthony Chen
Jesse Chen Matt Chung Aacer Daken Rajib Dutta
Mark Friend Philip Froese David Hargrove Robbie Harris
Kit Hui Toby Nixon Rahul Ramadas Andrea Severson
Kiran Shastry Nathan Sherman Ji Sun Shyamal Varma
Renesas Corporation – Promoter Company Employees
Tam Do Robert Dunstan Philip Leung Kiichi Muto
Ziba Nami Hajime Nozaki Raman Sargis Yoshiyuki Tomoda
Starry Tsai Jia Wei Toshifumi Yamaoka
STMicroelectronics – Promoter Company Employees
Nathalie Ballot Joel Huloux Gerard Mas
Texas Instruments – Promoter Company Employees
Mike Campbell Anant Gole Craig Greenburg Michael Koltun IV
Sai Karthik Rajaraman Anwar Sadat Cory Stewart Sue Vining
Deric Waters Gregory Watkins
Contributor Company Employees
ACON, Advanced- Victory Chen Conrad Choy Vicky Chuang
Connectek, Inc.
Jessica Feng Sharon Hsiao Wayne Wang
Advanced Micro Dennis Au Nat Barbiero Jason Chang
Devices
Michael Comai Walter Fry Will Harris
Jason Hawken Jim Hunkins Ling Kong
Scott Ogle Victor Salim Joseph Scanlon
Peter Teng
Allion Labs, Inc. Howard Chang Casper Lee Brian Shih
Analogix Greg Stewart Haijian Sui Yueke Tang
Semiconductor, Inc.
Ning Zhu
Anritsu Corporation Wataru Aoba John Jerico Custodio Kazuhiro Fujinuma

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© USB-IF 2021
Hiroshi Goto Alessandro Messina Tadanori Nishikobara
Ryo Sunayama Toshihiro Suzuki Mitsuhiro Usuba
Takeshi Wada
ASMedia Technology Chang Chinyu Chang Weiyun Chen Chiahsin
Inc.
Chen Chunhung Chuang Weber Kuo Han Sung
Lin Curtis Lin ShuYu Tseng PS
Tseng YD Wei Daniel Wu ShengChung
Avery Design Systems,
Chris Browy Chilai Huang Zhihong Zeng
Inc.
BitifEye Digital Test
Sebastian Muschala Hermann Stehling
Solutions GmbH
Bizlink Technology, Morphy Hsieh Kevin Tsai
Inc. Alex Chou
Cadence Design Marcin Behrendt Jacek Duda Shikha Gupta
Systems, Inc.
Gaurav Jain Poonam Khatri Yash Kothari
Vinod Lakshman Shivaji Magadum Andy Mauffet-Smith
Rohit Mishra Uyen Nguyen Raja Pounraj
Thirumal Reddy Anand RK Anshul Shah
Neelabh Singh Ofer Steinberg Mark Summers
Claire Ying Wasiq Zia
Corigine, Inc. Kevin Fan Ali Khan Xiao Xiao
Corning Optical Mark Bradley Wojciech Giziewicz Ian McKay
Communications LLC
Jamie Silva
Cypress Mark Fu Naman Jain Savan Javia
Semiconductor
Palani Subbiah
Dell Inc. Mohammed Hijazi Tom Lanzoni Ken Nicholas
Marcin Nowak Scott Ogle Adie Tan
Lee Zaretsky
Diodes Incorporated Qun Song
DisplayLink (UK) Ltd. Pete Burgers Dan Ellis
DJI Technology Co.,
Ltd. Steve Huang
Electronics Testing
Sophia Liu
Center, Taiwan
Elka International Ltd. Alvin Cheng Chloe Hsieh Roy Ting

IEC 62680-4-1:2022 - 11 -
© USB-IF 2021
Jui-Ming Yang
Ellisys Abel Astley Mario Pasquali Chuck Trefts
Tim Wei
Etron Technology, Inc. Andy Chen Shihmin Hsu Bryan Huang
Chien-Cheng Kuo Jen Hong Larn
Foxconn / Hon Hai Patrick Casher Joe Chen Jason Chou
Fred Fons Bob Hall Terry Little
Christine Tran A.J. Yang Jie Zheng
Fresco Logic Inc. Tim Barilovits Bob McVay Christopher Meyers
Jie Ni Jeffrey Yang
Genesys Logic, Inc. Sean Chen Gerry Chou Thomas Hsieh
Jerry Hu Perlman Hu Roy Huang
ChunYen Kuo Weddell Lee Jimmy Lin
Miller Lin D.C. Lu Greg Tu
Han Wu Yihsun Wu
Google Inc. Mark Hayter Benson Leung Raj Mojumder
David Schneider
Granite River Labs Nikhil Acharya Yun Han Ang Sandy Chang
Allen Chen Cyan Chen Swee Guan Chua
Alan Chuang Steven Lee Caspar Lin
Tim Lin Krishna Murthy Johnson Tan
Rajaraman V Chin Hun Yaep
Hotron Precision
Rosa Chen Patrick Yeh YF Zhang
Electronic Ind. Corp.
I-PEX (Dai-ichi Seiko) Alan Kinningham Ro Richard
Japan Aviation
Electronics Industry
Mark Saubert Junichi Takeuchi
Ltd.
JMicron Technology
Charon Chen Mika Cheng Kevin Liu
Corp.
Kandou Bus SA Brian Holden Hitaish Sharma David Stauffer
Andrew Stewart Mark Vennebarger
Keysight Technologies Atsushi Imaoka Biing Lin Lem Jit Lim
Inc.
Francis Liu Roland Scherzinger

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© USB-IF 2021
L&T Technology Binu Chinna Thankam Sunil Kumar Siddharth Pethe
Services
Badrinath Ramachandra Arunkumar Selvam Gayathri SN
LeCroy Corporation Alan Blankman Patrick Connally Carl Damn
David Fraticelli Daniel H Jacobs Farnoosh Jafary
Tyler Joe Carlo Mazzetti Mike Micheletti
Kathryn Morales Jeff Sabuda Joseph Schachner
Chris Webb
Lenovo Toshikazu Horino Shinji Matsushima Yuuki Matsuura
Nozomu Nagata Munefumi Nakata Kazuya Shibayama
Shunki Sugai Chikara Takahashi Masahiro Tokuno
Kayanagi Tsuneo
LG Electronics Inc. Do Kyun Kim Yoon Jong Lee Seung Yoo
Lintes Technology Co., Tammy Huang Charles Kaun RD Lintes
Ltd.
Max Lo CT Pien Jin Yi Tu
Jason Yang
Lotes Co., Ltd. Regina Liu-Hwang John Lynch
Luxshare-ICT Josue Casillo CY Hsu Antony Lin
John Lin Stone Lin Scott Shuey
Eric Wen Pat Young
Maxio Technology
George Fang
(Hangzhou) Ltd.
MediaTek Inc. Henry Chen Alexyc Lin Pochou Lin
Chiachun Wang
MegaChips
Rahul Agarwal Ramesh Dandapani Satoru Kumashiro
Corporation
Ryuichi Mariizumi Sireesha Vemulapalli Nobu Yanagisawa
Mercedes-Benz
Research &
Hans Wickler
Development, North
America, Inc.
Microchip Technology Mark Bohm Atish Ghosh Fernando Gonzalez
Inc.
Mark Gordon Richard Petrie Brigham Steele
Anthony Tarascio Robert Zakowicz
Molex LLC Alan MacDougall
MQP Electronics Ltd. Sten Carlsen Pat Crowe

IEC 62680-4-1:2022 - 13 -
© USB-IF 2021
Newnex Technology
Sam Liu
Corp.
NVIDIA Jamie Aitken Mark Overby
NXP Semiconductors Mahmoud El Sabbagh Ken Jaramillo Abhijeet Kulkarni
Vijendra Kuroodi Krishnan TN
Oculus VR LLC Marty Evans Joaquin Fierro Chao Hu
ON Semiconductor Eduardo De Reza Oscar Freitas Christian Klein
Amir Lahooti
Parade Technologies,
Jian Chen Jimmy Chiu Mark Qu
Inc.
Craig Wiley Paul Xu Kevin Yuan
Alan Yuen
Phison Electronics Jimmy Chen Ko Hong Lipp Sebastien Jean
Corp.
Stark Kuan Thomas Lee Anton Lin
Winnie Lu Wei Sui-Ning James Tsai
Michael Wu Fu-Hua Yang Chang Yuan-Cheng
Qualcomm, Inc Tomer Ben Chen Yiftach Benjamini Richard Burrows
Amit Gil James Goel Philip Hardy
Raja Jagadeesan Lalan Mishra Dmitrii Vasilchenko
Chris Wiesner
Realtek Semiconductor Chung-Chun Chen Jen Wen Chen Shen Chen
Corp.
Jonathan Chou Chang Ding Yao Feng
Bokai Huang An-Ming Lee Ray Lee
Ryan Lin Terry Lin Luobin Wang
Kay Yin Chris Zeng
Rohde & Schwarz
Johannes Ganzert Randy White
GmbH & Co. KG
Samsung Electronics Jaedeok Cha KangSeok Cho CheolYoon Chung
Co., Ltd.
Sangju Kim Termi Kwon Cheolho Lee
Edward Lee Jun Bum Lee Chahoon Park
Sunggeun Yoon
Seagate Technology Alvin Cox Paul McParland Michael Morgan
LLC
Cuong Tran
Silicon Line GmbH Ian Jackson
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© USB-IF 2021
Rakesh Polasa Satish Anand Verkila
SiliConch Systems
Private Limited
Kaustubh Kumar
Softnautics LLP Hetal Jariwala Dipakkumar Modi
Bhavesh Desai
Ujjwal Talati
Ishita Shah
James McGrath
Spectra7 Microsystems
Corp.
Alex Chow
Specwerkz Sydney Fernandes Amanda Hosler Diane Lenox
Soren Petersen
STMicroelectronics Nathalie Ballot Joel Huloux Gerard Mas
Sumitomo Electric Ind.,
Ltd., Optical Comm.
Sainer Siagian Mitsuaki Tamura
R&D Lab
Synaptics Inc. Jeff Lukanc Mark Miller Prashant Shamarao
Synopsys, Inc. Prishkrit Abrol Subramaniam Jeanne Cai
Aravindhan
Jun Cao Morten Christiansen Scott Guo
Eric Huang Joseph Juan Venkataraghavan
Krishnan
Jitendra Kushwaha Behram Minwalla Saleem Mohammad
Rick Schmidt Jasjeet Singh Mahendra Singh
John Stonick Zongyao Wen Fred Yu
Madhusudan Acharya Sourabh Das Keyur Diwan
Tektronix, Inc.
Mark Guenther Abhijeet Shinde Gary Simontom
Shuhei Yamamoto
Thine Electronics, Inc.
Simon Li Jeff Mason Jacky Mo
Tyco Electronics
Corp., a TE
Tommy Yu Yuanbo Zhang Tony Zhu
Connectivity Ltd.
company
Kai Inha
Varjo Technologies
Wayne Tseng
VIA Labs, Inc.
Benjamin Pan Terrance Shih Jay Tseng
VIA Technologies, Inc.
Fong-Jim Wang
Chao-Chee Ku Jeng Cheng Liu Wayne Lo
Weltrend
Semiconductor
Ho Wen Tsai Eric Wu Randolph Wu
Simon Yeh
David Landsman Larry McMillan Rob Ryan
Western Digital
Steve Bright Zach Moore Joe O’Brien
Wilder Technologies
Majid Shayegh
IEC 62680-4-1:2022 - 15 -
© USB-IF 2021
CONTENTS
1 Introduction . 41
1.1 Scope of the Document . 41
1.2 USB Product Compliance . 41
1.3 Document Organization . 41
1.4 Design Goals . 41
1.5 Related Documents . 41
1.6 Conventions . 42
1.6.1 Precedence . 42
1.6.2 Keywords . 42
1.6.2.1 Informative . 42
1.6.2.2 May . 42
1.6.2.3 N/A . 42
1.6.2.4 Normative . 42
1.6.2.5 Optional . 42
1.6.2.6 Reserved . 42
1.6.2.7 Shall . 42
1.6.2.8 Should . 43
1.6.3 Capitalization . 43
1.6.4 Italic Text . 43
1.6.5 Numbering . 43
1.6.6 Bit, Byte, DW, and Symbol Conventions . 43
1.6.7 Implementation Notes. 43
1.6.8 Connection Manager Notes . 43
1.6.9 Pseudocode . 43
1.6.10 CRC Algorithms . 44
1.6.11 FourCC . 44
1.7 Reserved Values and Fields . 44
1.8 Terms and Abbreviations . 45
2 Architectural Overview . 50
2.1 USB4 System Description . 50
2.1.1 Architectural Constructs . 52
2.1.1.1 Routers. 52
2.1.1.2 Adapters . 52
2.1.1.3 USB4 Ports and Links . 52
2.1.1.4 USB4 Devices . 53
2.1.1.5 USB4 Host . 54
2.1.1.6 Re-timers . 55
2.1.1.7 Connection Manager . 55
2.1.2 USB4 Mechanical . 55
2.1.3 USB4 Power . 55
2.1.4 USB4 System Configuration . 55
2.1.5 Thunderbolt™ 3 (TBT3) Compatibility Support. 55
2.1.6 USB Type-C Alternate Mode Compatibility Support . 56
2.2 USB4 Fabric Architecture . 56
2.2.1 USB4 Functional Stack . 56

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© USB-IF 2021
2.2.1.1 Electrical Layer . 57
2.2.1.2 Logical Layer . 57
2.2.1.3 Transport Layer . 57
2.2.1.4 Configuration Layer . 58
2.2.1.5 Protocol Adapter Layer . 58
2.2.2 USB4 Fabric Topology . 58
2.2.3 Paths . 59
2.2.4 Communication Constructs . 61
2.2.4.1 USB4 Link . 61
2.2.4.2 Sideband Channel . 62
2.2.5 USB4 Host-to-Host Communications . 63
2.2.6 Programming Model . 63
2.2.6.1 Connection Manager . 63
2.2.6.2 Configuration Spaces . 64
2.2.6.3 Operations . 64
2.2.7 Time Synchronization . 64
2.2.8 USB4 Fabric Data Integrity . 64
2.2.9 Global Life of a Router . 65
2.2.10 Protocol Tunneling . 65
2.2.10.1 USB3 Tunneling . 66
2.2.10.2 Display Tunneling . 70
2.2.10.3 PCIe Tunneling . 73
2.2.10.4 Host Interface Adapter . 77
3 Electrical Layer . 79
3.1 Sideband Channel Electrical Specifications . 80
3.2 USB4 Ecosystem . 81
3.2.1 Insertion-Loss Considerations (Informative) . 81
3.2.2 Coded Bit-Error-Ratio Considerations (Informative) . 82
3.3 USB4 Electrical Compliance Methodology . 82
3.3.1 System Compliance Test Point Definitions . 82
3.3.2 AC Coupling Capacitors . 83
3.3.3 Reference Clock-and-Data-Recovery (CDR) Function . 84
3.3.4 Reference Equalization Function . 84
3.3.4.1 Reference CTLE . 85
3.3.4.2 Reference DFE . 87
3.3.5 Time Domain Measurements . 87
3.3.6 Compliance Boards . 87
3.3.6.1 Compliance Plug Test Board. 87
3.3.6.2 Compliance Receptacle Test Board . 87
3.4 Router Assembly Transmitter Compliance . 87
3.4.1 Transmitter Specifications Applied for All Speeds . 87
3.4.1.1 Transmitter Frequency Variations during Link Training . 89
3.4.1.2 Transmitter Differential Return Loss . 90
3.4.1.3 Transmitter Common Mode Return Loss . 91
3.4.1.4 Transmit Equalization . 92
3.4.2 Transmitter Compliance Specifications for Gen 2 . 95
3.4.3 Transmitter Compliance Specifications for Gen 3 Interconnects . 97
3.5 Router Assembly Receiver Compliance . 98

IEC 62680-4-1:2022 - 17 -
© USB-IF 2021
3.5.1 Receiver Specifications Applied for All Speeds . 98
3.5.1.1 Receiver Differential Return Loss . 99
3.5.1.2 Receiver Common Mode Return Loss . 100
3.5.2 Receiver Uncoded BER Tolerance Testing . 101
3.5.3 Receiver Multi Error-Bursts Testing . 103
3.6 Captive Device Compliance . 105
3.6.1 Captive Device Compliance Test Setup . 105
3.6.2 Captive Device Transmitter Specifications . 105
3.6.2.1 Conducted Energy in Wireless Bands . 105
3.6.2.2 Transmitter Specifications . 106
3.6.2.3 Transmitter Differential Return Loss . 109
3.6.2.4 Transmitter Common Mode Return Loss . 109
3.6.2.5 Transmit Equalization . 109
3.6.3 Captive Device Receiver Specifications . 109
3.6.3.1 Receiver Specifications Applied for All Speeds . 109
3.6.3.2 Receiver Differential Return Loss . 110
3.6.3.3 Receiver Common Mode Return Loss . 110
3.6.4 Captive Device Receiver Uncoded BER Tolerance Testing . 111
3.6.5 Captive Device Receiver Multi Error-Bursts Testing . 112
3.7 Low Frequency Periodic Signaling (LFPS) . 113
3.7.1 LFPS Signal Definition . 113
3.8 Receiver Lane Margining (Testability) . 114
3.8.1 Background . 114
3.8.1.1 Software Margining Mode . 115
3.8.1.2 Hardware Margining Mode . 115
3.8.2 Receiver Voltage Margining and Timing Margining Requirements . 116
3.8.3 Receiver Parameter Access . 118
4 Logical Layer . 119
4.1 Sideband Channel . 119
4.1.1 Transactions . 120
4.1.1.1 Symbols . 120
4.1.1.2 Transaction Types . 120
4.1.1.3 SB Register Space . 128
4.1.2 Lane Initialization . 136
4.1.2.1 Phase 1 – Determination of Initial Conditions . 137
4.1.2.2 Phase 2 – Router Detection . 139
4.1.2.3 Phase 3 – Determination of USB4 Port Characteristics . 139
4.1.2.4 Phase 4 – Lane Parameters Synchronization and Transmit
Start . 140
4.1.2.5 Phase 5 – Link Equalization . 140
4.2 Logical Layer State Machine . 143
4.2.1 Lane Adapter State Machine . 143
4.2.1.1 Disabled . 144
4.2.1.2 CLd . 144
4.2.1.3 Training . 145
4.2.1.4 CL0 . 152
4.2.1.5 Lane Bonding . 153
4.2.1.6 Low Power (CL0s, CL1, and CL2) . 154

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© USB-IF 2021
4.2.2 USB4 Link Transitions . 170
4.2.2.1 Transition from One Single-Lane Link to Two Single-Lane
Links. 170
4.2.2.2 Transition from Two Single-Lane Links to Dual-Lane Link
...................................................................................... 171
4.2.2.3 Transition from Dual-Lane Link to Two Single-Lane Links
...................................................................................... 172
4.2.2.4 Transition from Two Single-Lane Links to One Single-Lane
Link . 172
4.2.3 Logical Layer Link State . 173
4.3 USB4 Link Encoding . 173
4.3.1 Lane Distribution . 175
4.3.2 Symbol Encoding . 176
4.3.2.1 Symbol Encoding of Transport Layer Bytes . 176
4.3.3 Ordered Sets . 177
4.3.4 Bit Swap . 178
4.3.4.1 Sync Bits . 178
4.3.4.2 Data Symbol Payload . 178
4.3.4.3 Ordered Set Symbol Payload . 179
4.3.5 Scrambling . 180
4.3.6 RS-FEC . 181
4.3.6.1 RS-FEC Activation and Deactivation . 183
4.3.6.2 Pre-Coding . 184
4.4 USB4 Link Operation . 184
4.4.1 Start of Data . 184
4.4.2 Error Cases and Recovery . 184
4.4.3 Clock Compensation and SKIP . 186
4.4.4 Dual-Lane Skew . 186
4.4.5 Disconnect . 187
4.4.5.1 Upstream Facing Port Disconnect . 187
4.4.5.2 Downstream Port Disconnect . 188
4.4.6 Lane Adapter Disable and Enable . 190
4.4.6.1 Disabled Adapter is the Upstream Adapter . 191
4.4.6.2 Disabled Adapter is not the Upstream Adapter . 192
4.4.7 Time Sync Notification Ordered Set (TSNOS) . 194
4.5 Sleep and Wake . 194
4.5.1 Entry to Sleep . 194
4.5.2 Behavior in Sleep State . 196
4.5.3 Wake Events . 196
4.5.4 Exit from Sleep . 197
4.5.4.1 Upstream Facing Port Disconnect . 197
4.5.4.2 Wake on USB4 Event . 197
4.6 Timing Parameters .
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