Revision 2.1 - 1 - UCSI Specification
June 2022
Copyright © 2022 USB Promoter Group. All rights reserved.
USB Type-C® Connector
System Software Interface
(UCSI) Specification
Apple Inc.
HP Inc.
Intel Corporation
Microsoft Corporation
Renesas Corporation
STMicroelectronics
Texas Instruments
Revision 2.1
June 2022
Revision 2.1 - 2 - UCSI Specification
June 2022
Copyright © 2022 USB Promoter Group. All rights reserved.
Release History
Revision
Comments
Issue Date
2.0
Initial release
January 2022
2.1
ECRs: EPR, CHUNKING Support, SET PDOS,
READ POWER LEVEL, PD REV, Clarification
for Connect Change
June 2022
Revision 2.1 - 3 - UCSI Specification
June 2022
Copyright © 2022 USB Promoter Group. All rights reserved.
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
Copyright © 2022, USB Promoter Group (Apple Inc., HP Inc., Intel Corporation, Microsoft
Corporation, Renesas Corporation, STMicroelectronics, and Texas Instruments).
Revision 2.1 - 4 - UCSI Specification
June 2022
Copyright © 2022 USB Promoter Group. All rights reserved.
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
Scott Jackson
HP Inc. – Promoter Company Employees
Intel Corporation – Promoter Company Employees
Dmitriy Berchanskiy
Venkataramani
Gopalakrishnan
Yaniv Hayat
Abdul Ismail
Guobin Liu
Uma Medepalli
Aruni Nelson
Rajaram Regupathy
Brad Saunders
Stephanie Wallick
Microsoft Corporation – Promoter Company Employees
Matt Chung
Rajib Dutta
Philip Froese
Nathan Sherman
Shyamal Varma
Andrew Yang
Renesas Corporation – Promoter Company Employees
Hajime Nozaki
Yuhuan Zhou
STMicroelectronics – Promoter Company Employees
Nathalie Ballot
Texas Instruments – Promoter Company Employees
Anant Gole
Shafiuddin Mohammed
Deric Waters
Gregory Watkins
Contributor Company Employees
ACON, Advanced-
Connectek, Inc.
Conrad Choy
Advanced Micro
Devices
Will Harris
Jason Hawken
Joseph Scanlon
Sujan Thomas
Allion Labs, Inc.
Otto Wei
Brian Shih
Shawn Tsou
Analogix
Semiconductor, Inc.
Greg Stewart
Ji Xin
eEver Technology,
Inc.
Chien-Cheng Kuo
Google, Inc,
Benson Leung
Infineon
Technologies
Ashok Kumar
Luxshare-ICT
John Lin
Microchip
Technology Inc.
Richard Petrie
Power Integrations
Shruti Anand
Rahul Joshi
Clomiferds Sales
Qualcomm, Inc.
Nicholas Cadieux
Jack Pham
Realtek
Semiconductor Corp.
Terry Lin
SiliConch Systems
Private Limited
Robin Chalana
Kaustubh Kumar
Shubham Paliwal
Rakesh Polasa
Revision 2.1 - 5 - UCSI Specification
June 2022
Copyright © 2022 USB Promoter Group. All rights reserved.
Specwerkz
Robert Dunstan
Synopsis, Inc.
Morten Christiansen
UNIGRAF OY
Steven Chen
Sergey Grushin
VIA Technologies,
Inc.
Jay Tseng
Weltrend
Semiconductor
Tony Lin
Jeng Cheng Liu
Wayne Lo
Ho Wen Tsai
Eric Wu
