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Proposed DisplayPort Alt Mode on USB Type-C

Standard

Version 1, Draft 3

28 July, 2014

Purpose

The purpose of this document is to specify the use of DisplayPort as an Alternate Mode for the USB Type-C connector.

Summary

This standard describes the use of the DisplayPort protocol between devices that support the USB Type-C connector using USB Type-C to USB Type-C Cable Assemblies. It describes cable assemblies that adapt the USB Type-C connector to Legacy DisplayPort connectors. It describes cable assemblies and adapters to adapt DisplayPort on USB Type-C to other video protocols. It describes the simultaneous use of USB Enhanced SuperSpeed and the DisplayPort protocol on the USB Type-C connector for docking applications.

This standard describes the USB Type-C connector pin assignments and DisplayPort signaling rates to be used in various scenarios when using the above cable assemblies and adapters. It describes how the USB-PD Alternate Mode Discovery and Entry Processes are applied to DisplayPort on the USB Type-C connector.

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Contents

Purpose .......................................................................................................................................................... 1 Summary ........................................................................................................................................................ 1 Contents ........................................................................................................................................................ 2 Figures .......................................................................................................................................................... 5 Tables ............................................................................................................................................................ 6 Preface .......................................................................................................................................................... 7 Intellectual Property ................................................................................................................................. 7

Trademarks .............................................................................................................................................. 7 Patents ..................................................................................................................................................... 8 Support for this Standard ........................................................................................................................... 8 Acknowledgements ................................................................................................................................... 8 Revision History ..................................................................................................................................... 10 Introduction ........................................................................................................................................... 11 Purpose ........................................................................................................................................ 11 Scope ........................................................................................................................................... 11 Related Documents ...................................................................................................................... 12 Conventions ................................................................................................................................. 12 1.4.1 Precedence ...................................................................................................................... 12 1.4.2 Keywords ........................................................................................................................ 12 1.4.3 Numbering ...................................................................................................................... 13 1.5 Terms and Abbreviations ............................................................................................................. 13 Overview ............................................................................................................................................... 15 2.1 Introduction ................................................................................................................................. 15 2.2 USB Type-C Receptacles, Plugs and Cables ................................................................................. 15 2.3 Signaling and cable types ............................................................................................................. 15 2.4 Multi-Function systems ................................................................................................................ 16 Pin Assignments and Descriptions .......................................................................................................... 17 3.1 Pin Assignments Overview ........................................................................................................... 17 3.2 USB Type-C DisplayPort Pin Assignments ................................................................................... 18

3.2.1 Pinout Assignment support requirements ......................................................................... 19 3.3 DFP_D Pin Assignment A ............................................................................................................ 21 3.4 DFP_D Pin Assignment B ............................................................................................................ 21 3.5 DFP_D Pin Assignment C ............................................................................................................ 22 3.6 DFP_D Pin Assignment D ............................................................................................................ 23 3.7 DFP_D Pin Assignment E ............................................................................................................ 24 3.8 DFP_D Pin Assignment F............................................................................................................. 26 3.9 UFP_D Pin Assignment A ............................................................................................................ 27 3.10 UFP_D Pin Assignment B ........................................................................................................... 28 3.11 UFP_D Pin Assignment C ........................................................................................................... 28 3.12 UFP_D Pin Assignment D ........................................................................................................... 29 3.13 UFP_D Pin Assignment E ........................................................................................................... 30 3.14 USB Gen 2 PHY signaling for DisplayPort (GEN2_BR) .............................................................. 31 3.15 AUX and HPD signaling ............................................................................................................. 31 Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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1.1 1.2 1.3 1.4

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3.15.1 AUX signaling ............................................................................................................... 31 3.15.2 HPD signaling ................................................................................................................ 32 3.15.3 AUX and HPD schematics .............................................................................................. 32 3.16 Legacy DisplayPort Connector CONFIG1 and CONFIG2 pins ..................................................... 35 USB Type-C Cable Assemblies used for DisplayPort ............................................................................. 36 4.1 Scenario 1 USB Type-C Full-Featured Cable Assembly ................................................................ 36

4.1.1 Scenario 1 USB Type-C Full-Featured cable Assembly using GEN2_BR ......................... 36 4.1.2 Scenario 1 USB Type-C Full-Featured cable Assembly using DP_BR .............................. 38 4.2 Scenarios 2a and 2b USB Type-C to Legacy DisplayPort Cable Assemblies ................................. 39

4.2.1 Scenario 2a USB Type-C DFP_D to Legacy DisplayPort UFP_D ..................................... 39 4.2.2 Scenario 2b Legacy DisplayPort DFP_D to USB Type-C UFP_D ..................................... 41 4.2.3 USB Type-C to Legacy DisplayPort Cable Assembly electrical properties ....................... 43 4.2.4 USB Type-C to Legacy DisplayPort Cable Assembly functionality .................................. 46 4.3 Scenarios 3a and 3c USB Type-C DFP_D to Protocol Converter ................................................... 48

4.3.1 HDMI Protocol Converter Adapters ................................................................................. 48 4.3.2 VGA Protocol Converter Adapters ................................................................................... 49 4.3.3 DVI Protocol Converter Adapters .................................................................................... 49 4.4 Scenario 4a USB Type-C DFP_D to a Multi-Function Dock (MF Dock) ....................................... 49

4.4.1 Scenario 4a USB Type-C Full-Featured Cable Assembly using GEN2_BR Multi-Function49 4.4.2 Scenario 4a USB Type-C Full-Featured Cable Assembly using DP_BR Multi-Function ... 50 4.5 Scenario 4b USB Type-C DFP_D to a VESA DockPort adapter .................................................... 52 4.6 Scenarios 4c/d USB Type-C DFP_D to Multi-Function cradle/captive cable dock ......................... 54

4.6.1 Scenarios 4c/d USB Type-C DFP_D to Multi-Function cradle dock using GEN2_BR

Multi-Function ............................................................................................................... 54

4.6.2 Scenario 4c/d USB Type-C DFP_D to Multi-Function cradle/captive cable dock using

DP_BR Multi-Function ................................................................................................... 56

Discovery and USB-PD .......................................................................................................................... 57 5.1 Connection discovery ................................................................................................................... 57 5.2 DisplayPort Mode discovery and entry/exit .................................................................................. 57

5.2.1 Structured VDM Header .................................................................................................. 57 5.2.2 DisplayPort Enter Mode .................................................................................................. 60 5.2.3 DisplayPort Status Update ............................................................................................... 60 5.2.4 DisplayPort Configure ..................................................................................................... 61 5.2.5 Attention ......................................................................................................................... 63 5.2.6 DisplayPort Exit Mode .................................................................................................... 63 5.3 VDM Message flows .................................................................................................................... Miscellaneous ........................................................................................................................................ 75 6.1 VCONN and VBUS ........................................................................................................................ 75 6.2 Low power operation ................................................................................................................... 75 6.3 Equivalent USB Functionality ...................................................................................................... 75 DisplayPort Alternate Mode Examples .................................................................................................. 76 A.1. Purpose ....................................................................................................................................... 76

A.1.1. DisplayPort Alternate Mode Examples ........................................................................... 76 A.2. USB Type-C USB Host to DisplayPort Video Adapter Example .................................................. 76

A.2.1. DisplayPort Video Adapter Assumptions ........................................................................ 76 A.2.2. Block Diagrams .............................................................................................................. 77 A.2.3. Solution ......................................................................................................................... 78

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A.3.1. USB Dock with DisplayPort Assumptions ...................................................................... 80 A.3.2. Block Diagrams .............................................................................................................. 81 A.3.3. Solution ......................................................................................................................... 81

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Figures

Figure 2-1 USB Type-C Full-Feature Receptacle Interface (Front View) (Informative) ................................................... 15 Figure 2-2 USB Type-C Full-Feature Plug Interface (Front View) (Informative) ............................................................. 15 Figure 3-1 AUX and HPD Signaling using USB Type-C to USB Type-C cable assemblies ............................................ 33 Figure 3-2 AUX and HPD Signaling using USB Type-C to Legacy DisplayPort Adapters .............................................. 34 Figure 3-3 AUX and HPD Signaling using Legacy DisplayPort to USB Type-C Adapters .............................................. 35 Figure 4-1 Scenario 1 ......................................................................................................................................................... 36 Figure 4-2 Scenario 1 GEN2_BR Cable Assembly Wiring ............................................................................................... 37 Figure 4-3 Scenario 1 DP_BR Cable Assembly Wiring .................................................................................................... 38 Figure 4-4 Scenario 2a ....................................................................................................................................................... 39 Figure 4-6 Scenario 2b ....................................................................................................................................................... 41 Figure 4-8 ILfit at HBR, HBR2 and HBR3 ....................................................................................................................... 43 Figure 4-9 IMR versus ILfit at HBR3 ................................................................................................................................ 44 Figure 4-10 IRL versus ILfit at HBR3 ............................................................................................................................... 45 Figure 4-11 Scenario 3a ..................................................................................................................................................... 48 Figure 4-13 Scenario 4a ..................................................................................................................................................... 49 Figure 4-14 Scenario 4a GEN2_BR MF Cable Assembly Wiring ..................................................................................... 50 Figure 4-15 Scenario 4a DP_BR MF Cable Assembly Wiring .......................................................................................... 51 Figure 4-16 Scenario 4b ..................................................................................................................................................... 52 Figure 4-18 Scenario 4c ..................................................................................................................................................... 54 Figure 5-1 Connect Initial Actions ...................................................................................................................................... Figure 5-2 DFP_U DisplayPort Alternate Mode Discovery and Entry ............................................................................... 65 Figure 5-3 DFP_U DisplayPort Configuration .................................................................................................................. 66 Figure 5-4 DFP_U DisplayPort Operation and Reconfiguration ....................................................................................... 67 Figure 5-5 DFP_U Reconfigure to USB Configuration ..................................................................................................... 68 Figure 5-6 DFP_U Exit Mode ............................................................................................................................................. 69 Figure 5-7 UFP_U DisplayPort Alternate Mode Discovery and Entry .............................................................................. 70 Figure 5-8 UFP_U USB Configuration Wait State ............................................................................................................ 71 Figure 5-9 UFP_U DisplayPort Configuration ................................................................................................................... 72 Figure 5-10 UFP_U DisplayPort Operation ....................................................................................................................... 73 Figure 5-11 UFP_U Exit Mode ........................................................................................................................................... 74 Figure 5-12 Hard Reset and Disconnection ....................................................................................................................... 74 Figure A-1 Host System Block Diagram ............................................................................................................................ 77 Figure A-2 DisplayPort Video Adapter Cable Assembly .................................................................................................. 78 Figure A-3 Example USB Dock with DisplayPort ............................................................................................................ 81

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Tables

Table 1-1 Terms and Abbreviations referenced from USB specifications ......................................................................... 13 Table 1-2 Terms and Abbreviations ................................................................................................................................... 14 Table 2-1 USB Type-C to USB Type-C DisplayPort Signaling ........................................................................................ 16 Table 3-1 USB Type-C Receptacle DFP_D Pin Assignment Summary ............................................................................. 18 Table 3-3 USB Type-C Receptacle DFP_D Pin Assignment Requirements ...................................................................... 20 Table 3-4 USB Type-C Receptacle UFP_D Pin Assignment Requirements ...................................................................... 20 Table 3-5 USB Type-C Plug DFP_D Pin Assignment Requirements................................................................................. 20 Table 3-6 USB Type-C Plug UFP_D Pin Assignment Requirements................................................................................. 20 Table 3-7 DFP_D Pin Assignment A .................................................................................................................................. 21 Table 4-1 USB Type-C DFP_D to Legacy DisplayPort UFP_D Usage ............................................................................. 40 Table 4-2 Legacy DisplayPort DFP_D to USB Type-C UFP_D Usage ............................................................................. 42 Table 4-3 Legacy DisplayPort Connector AUX states........................................................................................................ 46 Table 4-4 Legacy DisplayPort Connector HPD and AUX states ........................................................................................ 47 Table 4-5 Legacy DisplayPort Connector HPD and AUX states in adapter UFP_D configuration .................................... 47 Table 4-6 USB Type-C DFP_D to Legacy DockPort Receptacle ....................................................................................... 53 Table 4-7 USB Type-C Cable Assembly DisplayPort Usage (MF cradle/captive cable dock) GEN2_BR ........................ 55 Table 4-8 USB Type-C Cable Assembly DisplayPort Usage (MF cradle/captive cable dock) DP_BR ............................. 56 Table 5-1 VDM Message Header....................................................................................................................................... 58 Table 5-2 DisplayPort capabilities ..................................................................................................................................... 59 Table 5-3 DisplayPort Status ............................................................................................................................................. 61 Table 5-4 DisplayPort Configuration ................................................................................................................................. 62

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Preface

Intellectual Property

Company, Intel Corporation, Microsoft Corporation, Renesas Corporation, STMicroelectronics, and Texas Instruments and are reproduced with permission.

Extracts from drafts of Universal Serial Bus Type-C Cable and Connector Specification Revision 1.0, are Copyright © 2014 USB 3.0 Promoter Group and are reproduced with permission. Extracts from drafts of Universal Serial Bus Power Delivery Specification Revision 2.0 are Copyright © 2014, USB 2.0 Promoter Group and are reproduced with permission.

While every precaution has been taken in the preparation of this standard, the Video Electronics

Standards Association and its contributors assume no responsibility for errors or omissions, and make no warranties, expressed or implied, of functionality or suitability for any purpose.

Trademarks

Editor’s Note: FYI, the VESA trademark list will be updated after all content is included in this spec.

All trademarks used within this document are the property of their respective owners. DP, DisplayPort, Mini DisplayPort, mDP, and VESA are trademarks of the Video Electronics Standards Association.

HDMI is a licensed trademark of HDMI Licensing, LLC.

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Patents

VESA draws attention to the fact that it is claimed that compliance with this standard might

involve the use of a patent or other intellectual property right (collectively, “IPR”). VESA takes no position concerning the evidence, validity, and scope of this IPR.

The following holders of this IPR have assured VESA that they are willing to license the IPR on Reasonable and Non-Discriminatory (RAND) terms. The statement of the holder of this IPR is registered with VESA.

Table 1: Patents

Holder Name Contact Information Claims Known 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 2 265

Attention is drawn to the possibility that some of the elements of this VESA standard might be the subject of IPR other than those identified above. VESA shall not be held responsible for identifying any or all such IPR, and has made no inquiry into the possible existence of any such IPR.

THIS STANDARD IS BEING OFFERED WITHOUT ANY WARRANTY WHATSOEVER, AND IN PARTICULAR, ANY WARRANTY OF NON-INFRINGEMENT IS EXPRESSLY

DISCLAIMED. ANY IMPLEMENTATION OF THIS STANDARD SHALL BE MADE ENTIRELY AT THE IMPLEMENTER’S OWN RISK, AND NEITHER VESA, NOR ANY OF ITS MEMBERS OR SUBMITTERS, SHALL HAVE ANY LIABILITY WHATSOEVER TO ANY IMPLEMENTER OR THIRD PARTY FOR ANY DAMAGES OF ANY NATURE WHATSOEVER DIRECTLY OR INDIRECTLY ARISING FROM THE IMPLEMENTATION OF THIS STANDARD.

Support for this Standard

Clarifications and application notes to support this Standard might be written. To obtain the latest standard and any support documentation, contact VESA.

If you have a product that incorporates DisplayPort on a USB Type-C connector, ask the company that manufactured your product for assistance. If you are a manufacturer, VESA can assist you with any clarification you might require. Submit all comments or reported errors, in writing, to VESA, using one of the following methods: Fax: Email: Mail:

510-651-5127, direct this fax to Technical Support at VESA support@vesa.org

Technical Support

Video Electronics Standards Association 399 Balentine Drive, Suite 125 Newark, CA 94560

Acknowledgements

This document would not have been possible without the efforts of VESA's DisplayPort on USB Type-C Subgroup. In particular, Table 2 lists the individuals and their companies that

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contributed significant time and knowledge to this version of the standard.

Table 2: Main Contributors to DisplayPort on USB Type-C Standard

Name Jim Hunkins Mehran Badii Greg Stewart Sree Anantharanan Bill Cornelius Will Ferry Derek Iwamoto Souvik Mukherjee Anil Pannikkat Bob Ridenour Colin Whitby-Strevens Chris Pasqualino David Tsai Glenn Moore Steve Sedio David Schneider Simon Ellis Mike Hamann Christine Krause Jamie Johnston Greg Young Alan Kobayashi David Stears Craig Wiley Vijendra Kuroodi Chi Tai Hong Scott Shuey Richard Hubbard Yoon Lee Bob Crepps AMD Analogix Analogix Apple Apple Apple Apple Apple Apple Apple Apple Company Contribution Technical Content Technical Content Technical Content Technical Content Technical Content Technical Content Technical Content Technical Content Technical Content Technical Content Document Editor Technical Content Technical Content Technical Content Technical Content Technical Content Chairman Technical Content Technical Content Technical Content Technical Content Technical Content Technical Content Co-Chairman Technical Content Technical Content Technical Content Technical Content Technical Content Technical Content Broadcom Chrontel Foxconn Foxconn Google Intel Intel Intel Intel I-PEX Megachips Nvidia Parade Rohm Semtech TE Connectivity Texas Instruments Texas Instruments VTM Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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Revision History

Table 3: Revision History

Date July 2014 July 2014 Version D1 D2 Initial draft of the standard. Description Extensive editorial updates, including updated terminology Updated the values of the resistors and capacitors in the AUX and HPD circuits Updated the flow charts for Alternate Mode discovery and control Updated to VESA style and added VESA style introductory sections, updated to reflect DisplayPort TGR comment resolutions July 2014 D3 274

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1 Introduction

The USB Type-C specification envisages the support of Alternate Modes using the USB Type-C connector and

cables, in which various of the pins on the USB Type-C connector may be reconfigured to support interfaces outside the scope of USB Type-C.

The USB Type-C specification (and the USB-PD specification, which it leverages) provides a Discovery Process for the discovery of the support of Alternate Modes in connected devices, including specifying the means for switching into and out of a mode whereby the Alternate Mode is used on the USB Type-C connector. The USB Type-C specification gives rules by which Alternate Modes must abide.

This specification defines the use of DisplayPort as an Alternate Mode for the USB Type-C connector.

1.1 Purpose

The purpose of this specification is to enable an ecosystem in which the USB Type-C connector can be used to support DisplayPort and other video protocols (e.g. HDMI and VGA) in a way that is fully interoperable with existing DisplayPort and other video protocol products, with an emphasis on simplicity and ease of use with the minimum of cable types to minimize user confusion.

It defines the use of DisplayPort as an Alternate Mode on the USB Type-C to USB Type-C Cable Assembly, it defines cable assemblies that adapt the USB Type-C connector to Legacy DisplayPort connectors, it defines cable assemblies and adapters for DisplayPort on USB Type-C to other video protocols, and the simultaneous use of USB Enhanced SuperSpeed and DisplayPort for docking applications.

This specification defines the pinouts and DisplayPort signaling rates to be used in various scenarios using the above cable assemblies and adapters. It describes how the USB-PD Discovery Process is applied to DisplayPort on USB Type-C.

1.2 Scope

This specification is intended to complement the existing USB Type-C and DisplayPort 1.3 specifications. Normative information is provided to allow interoperability of components designed to this specification. Informative material, when provided, may illustrate possible design implementations.

Nothing in this specification is intended to change the normative requirements of the referenced USB and DisplayPort specifications. Extracts are copied from the referenced specifications to assist with clarity of description, but all such material is informative and the referenced specifications should be consulted for the

normative requirements. In the event of an apparent conflict between the requirements stated in this specification and similar requirements in the referenced specifications, then the referenced specifications shall prevail.

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1.3 Related Documents

USB Type-C

Universal Serial Bus Type-C Cable and Connector Specification Revision 1.0 – USB Implementers Forum, Inc http://www.usb.org/developers/docs

Universal Serial Bus Power Delivery Specification Revision 2.0 – USB Implementers Forum, Inc

http://www.usb.org/developers/docs

USB Billboard Device Class Specification, Revision 1.0, August xx, 2014 http://www.usb.org/developers/docs

Universal Serial Bus 3.1 Specification Revision 1.0 - USB Implementers Forum, Inc

http://www.usb.org/developers/docs

VESA® DisplayPort® Standard Version 1, Revision 3 XXX, 2014 http://www.vesa.org

VESA® DockPort® Standard Version 1.0, May 13, 2014

USB-PD

USB Billboard USB 3.1

DisplayPort 1.3 DockPort

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1.4 Conventions

1.4.1 Precedence

If there is a conflict between text, figures, and tables, the precedence shall be tables, figures, and then text.

1.4.2 Keywords

The following keywords differentiate between the levels of requirements and options.

1.4.2.1 May

May is a keyword that indicates a choice with no implied preference.

1.4.2.2 N/A

N/A is a keyword that indicates that a field or value is not applicable and has no defined value and shall not be checked or used by the recipient.

1.4.2.3 Optional

Optional is a keyword that describes features not mandated by this specification. However, if an optional feature is implemented, the feature shall be implemented as defined by this specification (optional normative).

1.4.2.4 Reserved

Reserved is a keyword indicating reserved bits, bytes, words, fields, and code values that are set-aside for future standardization. Their use and interpretation may be specified by future extensions to this specification and, unless otherwise stated, shall not be utilized or adapted by vendor implementation. A reserved bit, byte, word, or field shall be set to zero by the sender and shall be ignored by the receiver. Reserved field values shall not be sent by the sender and, if received, shall be ignored by the receiver.

1.4.2.5 Shall

Shall is a keyword indicating a mandatory requirement. Designers are mandated to implement all such requirements to ensure interoperability with other compliant Devices.

1.4.2.6 Should

Should is a keyword indicating flexibility of choice with a preferred alternative. Equivalent to the phrase “it is recommended that”.

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332 333 334 335 336 337 338 1.4.3 Numbering

Numbers that are immediately followed by a lowercase “b” (e.g., 01b) are binary values. Numbers that are

immediately followed by an uppercase “B” are byte values. Numbers that are immediately followed by a lowercase “h” (e.g., 3Ah) are hexadecimal values. Numbers not immediately followed by either a “b”, “B”, or “h” are decimal values.

1.5 Terms and Abbreviations

The following Terms and Abbreviations are defined in the USB Type-C specification, the USB 3.1 specification or the USB-PD specification, and are copied in Table 1-1 for information.

Table 1-1 Terms and Abbreviations referenced from USB specifications

Term Description (Informative) Active cable An Electronically Marked Cable with additional electronics to condition the data path signals. Captive cable A cable that is terminated on one end with a USB Type-C plug and has a vendor-specific connect means (hardwired or custom detachable) on the opposite end CC Configuration Channel. Enhanced An adjective referring to any valid collection of USB defined features SuperSpeed defined for the bus that runs over the SSRx and SSTx differential pairs in a USB 3.0 or USB 3.1 system. It is used in place of phrases like SuperSpeed/SuperSpeedPlus. Gen 1 Gen 1 is an adjective used to refer to the Physical layer associated with a 5.0 Gbps signaling rate. The original USB SuperSpeed Phy and a Gen 1 Phy refer to the same Phy. Gen 2 Gen 2 is an adjective used to refer to the Physical layer associated with a 10 Gbps signaling rate. Gen X Gen X is a generic term used to refer to any of the combinations USB 3.1 Gen 1, Gen 2 or Gen 1/Gen 2 when the topic is specific to the phy layers but does not need to be specific to either Gen 1 or Gen 2. Examples include: Gen X phy/connection. SVID Generic term for either a SID or a VID Initiator The port initiating a USB-PD Vendor Defined Message. It is independent of the port’s PD role (e.g., Provider, Consumer, Provider/Consumer, or Consumer/Provider). Passive cable A cable that does not incorporate any electronics to condition the data path signals. A passive cable may or may not be electronically marked. Responder The port responding to the Initiator of a USB-PD Vendor Defined Message. It is independent of the port’s PD role (e.g., Provider, Consumer, Provider/Consumer, or Consumer/Provider). SBU Sideband Use. SID A SID is a unique 16-bit unsigned value assigned by the USB-IF for a Standard ID SSRX USB SuperSpeed receiver differential pair (possibly qualified to indicate positive or negative side, and/or channel) SSTX USB SuperSpeed transmitter differential pair (possibly qualified to indicate positive or negative side, and/or channel) Proposed DisplayPort Alt Mode on USB Type-C

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Term Description (Informative) USB Type-C Plug A plug conforming to the mechanical and electrical requirements in the USB Type-C specification. USB Type-C Port The USB port associated to a USB Type-C receptacle. This includes the USB signaling, CC logic, multiplexers and other associated logic. USB Type-C A receptacle conforming to the mechanical and electrical requirements Receptacle of the USB Type-C specification. VID A VID is a unique 16-bit unsigned value assigned by the USB-IF to a Vendor 341 342 The terms and abbreviations given in Table 1-2 are introduced in this specification

343

Table 1-2 Terms and Abbreviations

Term Description DFP_U Downstream Facing Port, specified as “DFP” in the USB Type-C specification. Typically the ports on a host or the ports on a hub to which devices are connected. Direct connect The host’s DFP_U is connected directly, either via a cable or without (e.g., thumb drive), to the device’s UFP_U. DFP_D A port that is a Downstream Facing Port as defined in DisplayPort 1.3 and referred to as “DFP” in that specification Generally associated with a DisplayPort Source, but may also be associated with a DisplayPort Branch Device. DRP_U Dual-Role Port, specified as DRP in the USB Type-C specification. A port that can operate as either a DFP_U or a UFP_U. The role that the port offers may be fixed to either a DFP_U or UFP_U or may alternate between the two port states. The port’s role may be changed dynamically. DP_BR Bit rate and electrical signaling as specified in DisplayPort 1.3 (i.e. one of RBR, HBR, HBR2 and HBR3 GEN2_BR Bit rate and electrical signaling as specified in USB 3.1 using a Gen 2 PHY Legacy DisplayPort A connector or a DisplayPort port presented through a connector defined in DisplayPort 1.3 Multi-Function A configuration on the USB Type-C connector that combines USB 3.1 SuperSpeed signaling simultaneously with DisplayPort 1.3 signaling USB Type-C A generic reference to a USB Type-C Plug, USB Type-C Port, USB Type-C Receptacle or USB Type-C Cable Assembly as specified in USB Type-C UFP_U Upstream Facing Port, specified as “UFP” in the USB Type-C specification. The port on a device or a hub that connects to a host or the DFP_U of a hub. UFP_D A port that is an Upstream Facing Port as defined in DisplayPort 1.3 and referred to as a “UFP” in that specification Generally associated with a DisplayPort Sink, but may also be associated with a DisplayPort Branch Device. 344 Proposed DisplayPort Alt Mode on USB Type-C

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2 Overview

2.1 Introduction

Figure 2-1 illustrates the USB Type-C receptacle, as specified in the USB Type-C specification.

Figure 2-1 USB Type-C Full-Feature Receptacle Interface (Front View) (Informative)

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Figure 2-2 illustrates the comprehensive functional signal plan for the USB Type-C plug. The notable differences are that only one CC pin is connected through the cable and the “unused” CC pin is reconfigured as VCONN

(available as a power source for electronics that may be incorporated into USB Type-C plugs, cable assemblies or adaptors), and that there’s only one D+/D- pair instead of two.

Figure 2-2 USB Type-C Full-Feature Plug Interface (Front View) (Informative)

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2.2 USB Type-C Receptacles, Plugs and Cables

This specification uses the USB Type-C to USB Type-C Fully Featured cable assembly as defined in the USB Type-C specification.

In addition, this specification defines the following USB Type-C captive cables:

  

USB Type-C plug to Legacy DisplayPort/ Legacy mini DisplayPort plug cable assembly

USB Type-C plug to other video interface (e.g. HDMI, DVI, VGA) cable assembly (i.e. with a plug) or adaptor (i.e. with a receptacle)

USB Type-C plug to DockPort receptacle.

2.3 Signaling and cable types

This specification uses DisplayPort signaling speeds and electrical specifications as specified in the DisplayPort 1.3 specification (denoted DP_BR). In addition it anticipates a future specification defining the signaling speeds and electrical specifications for DisplayPort using the USB Gen 2 PHY as specified in the USB 3.1 specification, i.e. at 10 Gbps (nominally, more precisely likely to be 9.99Gbps, i.e. 270Mbps * 37). This signaling speed is denoted GEN2_BR.

Adapters (USB Type-C plug at one end and Legacy DisplayPort plug or DockPort receptacle at the other end) shall always use DP_BR.

USB Type-C captive protocol converters (USB Type-C plug on one end and non-DisplayPort video connector at the other end) shall always support DP_BR, but may also support GEN2_BR.

The various varieties of the Fully Featured USB Type-C to USB Type-C cable assembly support DP_BR and

GEN2_BR as specified in Table 2-1, which gives the maximum number of DisplayPort lanes that can be supported in each case. Each combination of DisplayPort and USB signaling is associated with a specific pin Assignment, Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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described in more detail in section 3.1. A DFP_D or UFP_D may support less than the maximum permitted number of lanes, as specified in section 3.2.1.

Note that Assignment C is mandatory for DFP_Ds and UFP_Ds that support DisplayPort on USB Type-C receptacles (see section 3.2.1), and so this provides a guarantee of interoperability on passive USB Type-C cables.

Table 2-1 USB Type-C to USB Type-C DisplayPort Signaling

Pin Assignment (see section 3.1) A B C D DisplayPort and USB Gen X Signaling GEN2_BR (No USB Gen X) Cable Type (Note 2) Gen 1 Passive (2m) Gen 2 Passive (1m) Gen 2 Active  4 2 GEN2_BR 1 channel USB Gen X DP_BR (No USB Gen X) DP_BR 1 channel USB Gen X Maximum number of DisplayPort lanes (Note 1) 2 14 4 2 2  382 383 384 385 386 387 388 3 390

Note 1: This cable is capable of supporting 1 channel of USB Gen 1, but is not capable of supporting GEN2_BR. Note 2: These cables are specified in USB Type-C. References to cable capabilities are informative.

2.4 Multi-Function systems

A USB Type-C interface may support USB SuperSpeed signaling as specified in USB 3.1, or DisplayPort signaling, as described in this specification, or both simultaneously on separate USB Type-C SuperSpeed data signal pairs. In some systems (such as docks) it may be desirable to be able to switch between various configurations, depending on what the user connects to the particular system. It may also be desirable to select a particular configuration when the system is first connected (still with the possibility of changing configuration later). To support this, a mechanism is provided for the system to indicate its preferred configuration to its port partner, see section 5.2.3.

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391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436

3 Pin Assignments and Descriptions

All USB Type-C pin Assignments specified in this document define the Assignments on the USB Type-C receptacle, assuming that the corresponding plug is inserted into the receptacle in normal orientation. The same Assignments apply to the corresponding plug when the plug is inserted into the receptacle in normal orientation. The system with the USB Type-C receptacle shall support the necessary muxing to provide the appropriate pin functions on the receptacle to match the plug pin Assignments when the plug is inserted into the receptacle in both normal and inverted orientation.

A USB Type-C receptacle that supports DFP_D functionality (e.g. it can act as a DisplayPort Source or as a DFP_D on a DisplayPort Branch device) shall support one or more DFP_D Assignments. Likewise, a USB Type-C

receptacle that supports UFP_D (e.g. it can act as a DisplayPort Sink or as the UFP_D on a DisplayPort Branch device) shall support one or more UFP_D Assignments.

A USB Type-C plug that is intended to plug directly into a receptacle-based DFP_D (e.g. it can act as a DisplayPort Sink or as the UFP_D on a DisplayPort Branch device) shall support one or more DFP_D Assignments. Likewise, a USB Type-C plug that is intended to plug directly into a receptacle-based UFP_D (e.g. it can act as a DisplayPort Source or as the DFP_D on a DisplayPort Branch device) shall support one or more UFP_D Assignments.

Note that port directionality advertised for a USB Type-C plug is opposite to the directionality of the DisplayPort functionality implemented behind the plug. For example, the protocol converter in a USB Type-C to HDMI or VGA protocol converter adapter will implement DisplayPort upstream functionality (it is a DisplayPort receiver), but the USB Type-C plug on the adapter will advertise a DFP_D Assignment as it is intended to plug into a USB Type-C DFP_D receptacle.

Assignments are advertised and configured as described in section 5.

All associations of USB Type-C functions with specific pins on the USB Type-C connector are informative. Reference should be made to USB Type-C for normative USB Type-C pin functionality.

3.1 Pin Assignments Overview

Six possible pinout Assignments are defined for USB Type-C when configured to act as a DFP_D and five possible pinout Assignments are defined for USB Type-C when configured to act as a UFP_D. The pinout Assignments in each case are identified by letter. The application of the various pinout Assignments to various scenarios is given in Section 4.

Assignments A, B, C and D are intended for use in conjunction with USB Type-C to USB Type-C cables and with adapters from USB Type-C to other video standards. The receptacles at each end of the cable shall use Assignments with the same letter. Assignments E and F are intended for use in conjunction with Adapters from USB Type-C to Legacy DisplayPort plugs or receptacles.

DisplayPort protocol is carried using GEN2_BR when using Assignments A and B, and is carried using DP_BR when using Assignments C, D, E and F.

Assignments B, D and F are used as variants of Assignments A, C and E respectively to carry one channel of USB Enhanced SuperSpeed protocol simultaneously with one or two lanes of DisplayPort. This configuration is described as Multi-Function.

Assignment B is the most constrained. This Assignment supports one lane of DisplayPort and one channel of USB Enhanced SuperSpeed over a USB Type-C active cable. Thus SSTX1/SSRX1 is used for USB Enhanced SuperSpeed and SSTX2 is used for one lane of DisplayPort and is assigned to ML0. SSRX2 is assigned to ML1 for use on the equivalent passive cables to support extra DisplayPort bandwidth.

Assignment F, which uses DisplayPort signaling rates in combination with one channel of USB Enhanced SuperSpeed, is designed to support the VESA DockPort standard.

Assignment E, which supports four lanes of DisplayPort using DisplayPort signaling rates, is derived from

Assignment F and assigns SSTX1 to ML2 and SSRX1 to ML3. This Assignment also supports the VESA DockPort standard.

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437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454

Assignments E and F allow the USB Type-C connector flip to be implemented by DFP_Ds which support reversal of pinout allocations (i.e. ML0, ML1, ML2 and ML3 can be reversed to ML3, ML2, ML1 and ML0 respectively). DFP_D Assignments C and D use the same Assignments as E and F to save on further muxing.

Assignment A supports two lanes of DisplayPort over a USB Type-C active cable. To minimize muxing from Assignment B, SSTX2 is assigned to ML0 and SSTX1 is assigned to ML1. To extend this pinout to be used on

equivalent passive cables, SSRX1 is assigned to ML3 to be compatible with DFP_D Assignment C, leaving SSRX2 to be assigned to ML2.

UFP_D Assignments A, B, C and D are derived from the corresponding DFP_D Assignments, taking into account the A2/3 to B11/10, A11/10 to B2/3 and SBU1 to SBU2 crossovers in the USB Type-C to USB Type-C cable assembly. UFP_D Assignment E is derived from DFP_D Assignment E, taking into account the requirement that the USB Type-C to Legacy DisplayPort (or Legacy mini DisplayPort) cable assembly should be reversible. This, in effect, exchanges ML0, ML1, ML2 and ML3 with ML3, ML2, ML1 and ML0. UFP_D Assignment E also has +/- polarity inversion on all pin pairs.

3.2 USB Type-C DisplayPort Pin Assignments

Table 3-1 summarizes the DFP_D pin Assignments and Table 3-2 summarizes the UFP_D pin Assignments. In both cases, these show the Assignments when the attached plug is in normal orientation. The USB Type-C rules for connector rotation apply when the attached plug is inserted in the flipped orientation.

Table 3-1 USB Type-C Receptacle DFP_D Pin Assignment Summary

Assignment Cable DisplayPort Signaling A USB Type-C to USB Type-C or Adapter GEN2_BR B USB Type-C to USB Type-C or Adapter GEN2_BR C USB Type-C to USB Type-C or Adapter DP_BR D USB Type-C to USB Type-C or Adapter DP_BR E USB Type-C to Legacy DP DP_BR F USB Type-C to Legacy DP DP_BR Receptacle Pin number A11/10 A2/3 B11/10 B2/3 A8 B8 Open/ ML2 ML1 Open/ ML3 ML0 AUX_P/HPD AUX_N/HPD Open/ ML1 SSTX SSRX ML0 AUX_P/HPD AUX_N/HPD ML0 ML2 ML3 ML1 AUX_P/HPD AUX_N/HPD ML0 SSTX SSRX ML1 AUX_P/HPD AUX_N/HPD ML0 ML2 ML3 ML1 AUX_P/HPD AUX_N/HPD ML0 SSTX SSRX ML1 AUX_P/HPD AUX_N/HPD 455 Note: Connections marked as optionally Open are not used when active cables are connected.

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Table 3-2 USB Type-C Receptacle UFP_D Pin Assignment Summary

Assignment Cable Receptacle Pin number A11/10 A2/3 B11/10 B2/3 A8 B8 DisplayPort Signaling A USB Type-C to USB Type-C or Adapter GEN2_BR ML0 Open/ ML3 ML1 Open/ ML2 AUX_N/HPD AUX_P/HPD B USB Type-C to USB Type-C or Adapter GEN2_BR ML0 SSTX SSRX Open/ ML1 AUX_N/HPD AUX_P/HPD C USB Type-C to USB Type-C or Adapter DP_BR ML1 ML3 ML2 ML0 AUX_N/HPD AUX_P/HPD D USB Type-C to USB Type-C or Adapter DP_BR ML1 SSTX SSRX ML0 AUX_N/HPD AUX_P/HPD E Legacy DP to USB Type-C DP_BR ML3 ML1 ML0 ML2 AUX_P/HPD AUX_N/HPD 457 458 459 460 461 462 463 4 465 466 467

Note: Connections marked as optionally Open are not used when active cables are connected.

Note: The polarity on each lane is inverted when Assignment E is used at the UFP_D receptacle. AUX_P and AUX_N are inverted with respect to the other Assignments when Assignment E is used at the UFP_D receptacle. Pins A2, A3, B2 and B3 shall be AC coupled in receptacle-based systems between the port orientation switch and the connector. Pins A10, A11, B10 and B11 shall be DC coupled in receptacle-based systems. These requirements match the requirements for the use of these pins for USB Enhanced SuperSpeed operation. Adapter cables and plug-based systems shall include AC capacitors on pins A10, A11, B10 and B11.

3.2.1 Pinout Assignment support requirements

Table 3-3 and Table 3-4 show the required assignments for a USB Type-C receptacle that supports DisplayPort. The required assignments depend on whether the port also implements a USB Host or a USB Device (including a USB UFP that supports a Powered Accessory).

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Table 3-3 USB Type-C Receptacle DFP_D Pin Assignment Requirements

Assignment Cable DisplayPort Signaling A B C D E F USB Type-C to USB Type-C to USB Type-C to USB Type-C to USB Type-C to USB Type-C to USB Type-C or USB Type-C or USB Type-C or USB Type-C or Legacy DP Legacy DP Adapter Adapter Adapter Adapter GEN2_BR GEN2_BR Required if A is supported, otherwise prohibited Optional DP_BR DP_BR DP_BR DP_BR USB Host Optional Required Optional Required Optional USB Device Optional Required Optional Required (Not applicable) 469

Table 3-4 USB Type-C Receptacle UFP_D Pin Assignment Requirements

Assignment Cable DisplayPort Signaling A USB Type-C to USB Type-C or Adapter GEN2_BR B USB Type-C to USB Type-C or Adapter GEN2_BR Required if A is supported, otherwise prohibited Optional C USB Type-C to USB Type-C or Adapter DP_BR D USB Type-C to USB Type-C or Adapter DP_BR E USB Type-C to Legacy DP DP_BR USB Host Optional Required Optional Required USB Device Optional Required Optional Required 470 471

Table 3-5 and Table 3-6 show the required assignments for a USB Type-C plug that supports DisplayPort.

Table 3-5 USB Type-C Plug DFP_D Pin Assignment Requirements

USB Host USB Device Assignment DisplayPort Signaling A GEN2_BR Optional Optional B GEN2_BR Optional Optional C DP_BR Required Required D DP_BR Optional Optional E DP_BR Required Required F DP_BR (Not applicable) Optional 472

Table 3-6 USB Type-C Plug UFP_D Pin Assignment Requirements

Assignment DisplayPort Signaling A GEN2_BR B GEN2_BR Required if A is supported, otherwise prohibited Optional C DP_BR D DP_BR E DP_BR USB Host Optional Required Optional Required USB Device Optional Required Optional Required 473 474 475 476 477

Systems supporting a DFP_D on a USB Type-C receptacle shall support HBR.

Systems supporting a DFP_D or a UFP_D on a USB Type-C receptacle may support one, two or four lanes of DisplayPort, according to system functionality.

Adapters and captive cable docks supporting a DFP_D on a USB Type-C plug and adapting this to a Legacy DisplayPort connector shall be capable of supporting four lanes of DisplayPort.

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478 479 480 481 482 483 484 485 486 487 488 4 490 491 492 493 494

Adapters and captive cable docks supporting a DFP_D on a USB Type-C plug and adapting this to a non-DisplayPort video interface may support two or four lanes of DisplayPort, according to adapter functionality.

Note: DVI adapters and VGA adapters need to support two lanes of HBR, and HDMI adapters need to support four lanes of HBR2, as a consequence of minimum display mode support requirements given in section 4.3.

Cradle docks supporting DisplayPort on a USB Type-C plug are typically designed to complement a specific product or product family, and typically are restricted by mechanical constraints. Accordingly, they may support one, two or four lanes of DisplayPort, according to the functionality of the complementary system.

Note: the number of DisplayPort lanes used at any moment in time for a particular connection follows the DisplayPort specification requirements.

3.3 DFP_D Pin Assignment A

The usage and configuration of the USB Type-C connector pins when reconfigured to support DisplayPort using GEN2_BR signaling, assuming normal plug orientation, is defined in Table 3-7. This pinout is appropriate only for USB Type-C to USB Type-C cables and UFP_Ds with USB Type-C plugs, but supports both Passive and Active Gen 2 cables. This pinout does not support Gen 1 cables, as these do not support GEN2_BR (see USB Type-C for the capabilities of the various USB Type-C to USB Type-C cables). See section 3.14 for further details on GEN2_BR signaling.

Table 3-7 DFP_D Pin Assignment A

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Positive half of Lane 1 Negative half Lane 1 Negative half of Lane 2 Positive half of Lane 2 Ground return DisplayPort Function GND ML1+ ML1- (Type-C)* (Type-C)* (Type-C)* (Type-C)* AUX_P/HPD (Type-C)* ML2- (1) ML2+ (1) GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Positive half of Lane 3 Negative half of Lane 3 Negative half of Lane 0 Positive half of Lane 0 Ground return DisplayPort Function GND ML3+ (1) ML3- (1) (Type-C)* AUX_N/HPD (Type-C)* (Type-C)* (Type-C)* (Type-C)* ML0- ML0+ GND 495 496 497 498 499 500

*(Type-C) denotes no change from the USB Type-C specification Note 1: Passive Gen 2 cables only, not Active Gen 2 cables

3.4 DFP_D Pin Assignment B

The usage and configuration of the USB Type-C connector pins when reconfigured to support DisplayPort using

GEN2_BR signaling combined with USB SuperSpeed (Multi-Function), assuming normal plug orientation, is defined in Table 3-8. This pinout is appropriate only for USB Type-C to USB Type-C cables and UFP_Ds with USB Type-C

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501 502 503 504

plugs. It supports two lanes of DisplayPort for Passive Gen 2 cables but only supports one lane of DisplayPort for Active Gen 2 cables.

See section 3.14 for further details on GEN2_BR signaling.

Table 3-8 DFP_D Pin Assignment B

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Negative half of Lane 1 Positive half of Lane 1 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_P/HPD (USB Type-C)* ML1- (1) ML1+ (1) GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Negative half of Lane 0 Positive half of Lane 0 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_N/HPD (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* ML0- ML0+ GND 505 506 507 508 509

*(USB Type-C) denotes no change from the USB Type-C specification. Note (1) Passive Gen 2 cables only.

3.5 DFP_D Pin Assignment C

The usage and configuration of USB Type-C connector pins when reconfigured to support for DisplayPort using DP_BR signaling, assuming normal plug orientation, is defined in Table 3-9. The DisplayPort electrical signaling

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510 511 512 513 514

when using this pinout shall comply with DisplayPort 1.3 for transmission at RBR, HBR, HBR2 or HBR3 bit rates, as supported by the system. The encoding and higher level signaling shall be 8B10B as defined in DisplayPort 1.3. This pinout is appropriate only for passive USB Type-C to USB Type-C cables and UFP_Ds with USB Type-C plugs.

Table 3-9 DFP_D Pin Assignment C

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Positive half of Lane 2 Negative half of Lane 2 Negative half of Lane 0 Positive half of Lane 0 Ground return DisplayPort Function GND ML2+ ML2- (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_P/HPD (USB Type-C)* ML0- ML0+ GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Positive half of Lane 3 Negative half of Lane 3 Negative half of Lane 1 Positive half of Lane 1 Ground return DisplayPort Function GND ML3+ ML3- (USB Type-C)* AUX_N/HPD (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* ML1- ML1+ GND 515 516 517 518 519

*(USB Type-C) denotes no change from the USB Type-C specification.

3.6 DFP_D Pin Assignment D

The usage and configuration of the USB Type-C connector pins when reconfigured to support for DisplayPort using DP_BR signaling combined with USB SuperSpeed (Multi-Function), assuming normal plug orientation, is defined in Table 3-10. The DisplayPort electrical signaling when using this pinout shall comply with DisplayPort 1.3 for

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520 521 522 523 524

transmission at RBR, HBR, HBR2 and HBR3 bit rates, as supported by the system. The encoding and higher level signaling shall be 8B10B as defined in DisplayPort 1.3.

This pinout is appropriate only for passive USB Type-C to USB Type-C cables and UFP_Ds with USB Type-C plugs.

Table 3-10 DFP_D Pin Assignment D

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Negative half of Lane 0 Positive half of Lane 0 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_P/HPD (USB Type-C)* ML0- ML0+ GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Negative half of Lane 1 Positive half of Lane 1 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_N/HPD (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* ML1- ML1+ GND 525 526 527 528 529

*( USB Type-C) denotes no change from the USB Type-C specification.

3.7 DFP_D Pin Assignment E

The usage and configuration of the USB Type-C connector pins when reconfigured to support for DisplayPort using DP_BR signaling, assuming normal plug orientation, is defined in Table 3-11. The DisplayPort electrical signaling when using this pinout shall comply with DisplayPort 1.3 for transmission at RBR, HBR, HBR2 and HBR3 bit rates,

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530 531 532 533 534 as supported by the system, except that the reference cable model shall be for the USB Type-C to DP cable defined in Section 4.2.3.

This pinout is appropriate only for USB Type-C to Legacy DisplayPort cables and USB Type-C to Legacy DisplayPort DockPort adaptors, but supports both Passive and Active cables.

Note: the reference cable has lower loss than the HBR reference cable in DisplayPort 1.3 in order to permit higher 535 losses in the system design due to the need for signal muxing.

536

Table 3-11 DFP_D Pin Assignment E

Pin Description DisplayPort Pin Description DisplayPort Function Function A1 Ground return GND B12 Ground return GND A2 Positive half of Lane 2 ML2+ B11 Positive half of Lane 3 ML3+ A3 Negative half of Lane 2 ML2- B10 Negative half of Lane 3 ML3- A4 (USB Type-C)* B9 (USB Type-C)* A5 (USB Type-C)* B8 AUX_N/HPD A6 (USB Type-C)* B7 (USB Type-C)* A7 (USB Type-C)* B6 (USB Type-C)* A8 AUX_P/HPD B5 (USB Type-C)* A9 (USB Type-C)* B4 (USB Type-C)* A10 Negative half of Lane 0 ML0- B3 Negative half of Lane 1 ML1- A11 Positive half of Lane 0 ML0+ B2 Positive half of Lane 1 ML1+ A12 Ground return GND B1 Ground return GND 537 *( USB Type-C) denotes no change from the USB Type-C specification.

Proposed DisplayPort Alt Mode on USB Type-C

538 539 540 541 542 543 544 545 546 547 3.8 DFP_D Pin Assignment F

The usage and configuration of the USB Type-C connector pins when reconfigured to support for DisplayPort using DP_BR signaling combined with USB Gen 1 signaling (Multi-Function), assuming normal plug orientation, is defined in Table 3-12.

The DisplayPort electrical signaling when using this pinout shall comply with DisplayPort 1.3 for transmission at RBR, HBR, HBR2 and HBR3 bit rates, as supported by the system.

This pinout is appropriate only for Adapters that adapt DisplayPort on USB Type-C to Legacy DisplayPort

receptacles that are then connected to DisplayPort captive cables that support simultaneous DisplayPort and USB Gen 1 signaling as defined in the VESA DockPort specification. USB Gen 2 signaling is not supported as this pin Assignment is intended for use with a DisplayPort receptacle, which is not specified to support Gen 2 signaling 548 rates.

549

Table 3-12 DFP_D Pin Assignment F

Pin Description DisplayPort Pin Description DisplayPort Function Function A1 Ground return GND B12 Ground return GND A2 (USB Type-C)* B11 (USB Type-C)* A3 (USB Type-C)* B10 (USB Type-C)* A4 (USB Type-C)* B9 (USB Type-C)* A5 (USB Type-C)* B8 AUX_N/HPD A6 (USB Type-C)* B7 (USB Type-C)* A7 (USB Type-C)* B6 (USB Type-C)* A8 AUX_P/HPD B5 (USB Type-C)* A9 (USB Type-C)* B4 (USB Type-C)* A10 Negative half of Lane 0 ML0- B3 Negative half of Lane 1 ML1- A11 Positive half of Lane 0 ML0+ B2 Positive half of Lane 1 ML1+ A12 Ground return GND B1 Ground return GND 550 *( USB Type-C) denotes no change from the USB Type-C specification.

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551 552 553 554 555 3.9 UFP_D Pin Assignment A

This pinout is appropriate only for USB Type-C to USB Type-C cables and DFP_Ds with USB Type-C plugs, but 556 supports both Passive and Active cables.

557

Table 3-13 UFP_D Pin Assignment A

Pin Description DisplayPort Pin Description DisplayPort Function Function A1 Ground return GND B12 Ground return GND A2 Positive half of Positive half of Main Link 3 ML3+ (1) B11 Main Link 1 ML1+ A3 Negative half of Negative half of Main Link 3 ML3- (1) B10 Main Link 1 ML1- A4 (USB Type-C)* B9 (USB Type-C)* A5 (USB Type-C)* B8 AUX_P/HPD A6 (USB Type-C)* B7 (USB Type-C)* A7 (USB Type-C)* B6 (USB Type-C)* A8 AUX_N/HPD B5 (USB Type-C)* A9 (USB Type-C)* B4 (USB Type-C)* A10 Negative half of Main Link 0 ML0- B3 Negative half of Main Link 2 ML2- (1) A11 Positive half of Main Link 0 ML0+ B2 Positive half of Main Link 2 ML2+ (1) A12 Ground return GND B1 Ground return GND 558 *( USB Type-C) denotes no change from the USB Type-C specification. 559

Note (1): Passive cables only.

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3.10 UFP_D Pin Assignment B

The usage and configuration of the USB Type-C connector pins when reconfigured to support DisplayPort using

GEN2_BR signaling combined with USB SuperSpeed (Multi-Function), assuming normal plug orientation, is defined in Table 3-14. See section 3.14 for further details on GEN2_BR signaling.

This pinout is appropriate only for USB Type-C to USB Type-C cables and DFP_Ds with USB Type-C plugs. It supports two lanes of DisplayPort for Passive cables but only supports one lane of DisplayPort for Active cables.

Table 3-14 UFP_D Pin Assignment B

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Negative half of Lane 0 Positive half of Lane 0 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_N/HPD (USB Type-C)* ML0- ML0+ GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Negative half of Lane 1 Positive half of Lane 1 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_P/HPD (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* ML1- (1) ML1+ (1) GND 567 568 569 570 571

*( USB Type-C) denotes no change from the USB Type-C specification. (1) Passive cable only.

3.11 UFP_D Pin Assignment C

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when using this pinout shall comply with DisplayPort 1.3 for transmission at RBR, HBR, HBR2 and HBR3 bit rates, as supported by the system. The encoding and higher level signaling shall be 8B10B as defined in DisplayPort 1.3. This pinout is appropriate only for passive USB Type-C to USB Type-C cables and DFP_Ds with USB Type-C plugs.

Table 3-15 UFP_D Pin Assignment C

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Positive half of Lane 3 Negative half of Lane 3 Negative half of Lane 1 Positive half of Lane 1 Ground return DisplayPort Function GND ML3+ ML3- (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_N/HPD (USB Type-C)* ML1- ML1+ GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Positive half of Lane 2 Negative half of Lane 2 Negative half of Lane 0 Positive half of Lane 0 Ground return DisplayPort Function GND ML2+ ML2- (USB Type-C)* AUX_P/HPD (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* ML0- ML0+ GND 577 578 579 580 581

*(USB Type-C) denotes no change from the USB Type-C specification.

3.12 UFP_D Pin Assignment D

The usage and configuration of the USB Type-C connector pins when reconfigured to support DisplayPort using DP_BR signaling combined with USB SuperSpeed (Multi-Function), assuming normal plug orientation, is defined in Table 3-16. The DisplayPort electrical signaling when using this pinout shall comply with DisplayPort 1.3 for

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582 583 584 585 586

transmission at RBR, HBR, HBR2 and HBR3 bit rates, as supported by the system. The encoding and higher level signaling shall be 8B10B as defined in DisplayPort 1.3.

This pinout is appropriate only for passive USB Type-C to USB Type-C cables and DFP_Ds with USB Type-C plugs.

Table 3-16 UFP_D Pin Assignment D

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Negative half of Lane 1 Positive half of Lane 1 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_N/HPD (USB Type-C)* ML1- ML1+ GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Negative half of Lane 0 Positive half of Lane 0 Ground return DisplayPort Function GND (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_P/HPD (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* ML0- ML0+ GND 587 588 5 590 591

*(USB Type-C) denotes no change from the USB Type-C specification.

3.13 UFP_D Pin Assignment E

The usage and configuration of the USB Type-C connector pins when reconfigured to support DisplayPort using DP_BR signaling, assuming normal plug orientation, is defined in Table 3-17. The DisplayPort electrical signaling when using this pinout shall comply with DisplayPort 1.3 for transmission at RBR, HBR, HBR2 and HBR3 bit rates,

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592 593 594 595 596 597 598

as supported by the system, except that the reference cable model shall be for the USB Type-C to DP cable defined in Section 4.2.3.

This pinout is appropriate only for Legacy DisplayPort to USB Type-C cables, but supports both Passive and Active cables.

Note: the reference cable has lower loss than the HBR reference cable in DisplayPort 1.3 in order to permit higher losses in the system design due to the need for signal muxing.

Table 3-17 UFP_D Pin Assignment E

Pin A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Description Ground return Negative half of Lane 1 Positive half of Lane 1 Positive half of Lane 3 Negative half of Lane 3 Ground return DisplayPort Function GND ML1- ML1+ (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* AUX_P/HPD (USB Type-C)* ML3+ ML3- GND Pin B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Description Ground return Negative half of Lane 0 Positive half of Lane 0 Positive half of Lane 2 Negative half of Lane 2 Ground return DisplayPort Function GND ML0- ML0+ (USB Type-C)* AUX_N/HPD (USB Type-C)* (USB Type-C)* (USB Type-C)* (USB Type-C)* ML2+ ML2- GND 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617

*( USB Type-C) denotes no change from the USB Type-C specification

Note the inverted use of A8/B8 (AUX+/AUX-) and inverted polarity of the main link lanes on A2/A3, A10/A11, B11/B10 and B3/B2 compared to the UFP_D Pin Assignments A, B, C and D.

3.14 USB Gen 2 PHY signaling for DisplayPort (GEN2_BR)

DisplayPort protocol may be transmitted and received using the electrical specifications defined in USB 3.1 for the Gen 2 PHY (GEN2_BR).

This version of this specification does not provide a complete specification for GEN2_BR. However it is anticipated that a complete specification will be added as a new PHY in a revision of DisplayPort 1.3. This specification

provides the basis upon which it is anticipated that the complete specification for GEN2_BR will be developed. In the event of conflict the new PHY in the anticipated revision of DisplayPort 1.3 takes precedence.

When transmitting/receiving at GEN2_BR, the DFP_D or UFP_D shall comply with sections 6.5, 6.6, 6.7, 6.8, 6.10 and 6.11 of USB 3.1.

Open issues in the definition of GEN2_BR include encoding and training, the alternatives being to maintain

DisplayPort 8B10B encoding and DisplayPort training (possibly with some form of Gen 2 PHY training), or to use Gen 2 128B132B encoding with some form of mapping of the DisplayPort protocol.

3.15 AUX and HPD signaling

3.15.1 AUX signaling

AUX shall be supported on the USB Type-C connector when operating in DisplayPort Alternate Mode using

differential 100 Ohm terminated signaling on the A8 and B8 receptacle connection. AC coupling capacitors shall be Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED V1, d3

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placed between the AUX+/- transceiver and the USB Type-C receptacle. The HPD common mode signal shall be presented on the receptacle side of the AC coupling capacitors. The AUX differential signal levels shall be as specified in DisplayPort 1.3, with the exception that the eye diagrams are measured for 1 UI after a differential signal transition. The AUX common mode signal levels as specified in DisplayPort 1.3 are not used. Instead the AUX common mode is used to carry the state of the HPD signal (see section 3.15.2). Consequently, the system’s SBU isolation and plug orientation switches need to support a Vpass voltage, i.e. the voltage that is allowed to pass through the switch without clipping, which may range between -0.35V to 3.95V. Adapter cables shall incorporate an AC capacitor on each of the AUX signal wires to isolate the AUX common mode on the Legacy DisplayPort

connector side from the AUX common mode on the USB Type-C connector side that is used to carry the HPD signal. Note that the receptacle connection is disconnected in the system until the connection is switched into DisplayPort Alternate Mode and a configuration is selected. Likewise, the plug connection on adapter cables is disconnected until the connection is switched into DisplayPort Alternate Mode and a configuration is selected.

3.15.2 HPD signaling

HPD shall be supported on the USB Type-C connector when operating in DisplayPort Alternate Mode by applying the HPD signal to the AUX common mode.

Note that the receptacle connection is disconnected in the system until the connection is switched into DisplayPort Alternate Mode and a configuration is selected. Likewise, the plug connection on adapter cables is disconnected until the connection is switched into DisplayPort Alternate Mode and a configuration is selected.

3.15.3 AUX and HPD schematics

The AUX and HPD implementations are designed to support the scenarios described in Section 4, which may use a USB Type-C to USB Type-C cable assembly, a USB Type-C to Legacy DisplayPort cable assembly, or a USB Type-C protocol converter cable assembly or adapter. See section 4.2.4.2 for the behavior of these adapters for Legacy DisplayPort DFP_D/UFP_D detection.

The tolerance on the resistors shown in Figure 3-1, Figure 3-2 and Figure 3-3 is ±5%, and the tolerance on the capacitors is ±20%, except for the capacitors on the Legacy DisplayPort systems, where the minimum/maximum values are shown.

Figure 3-1 shows the system design of a DFP_D on a USB Type-C connector connected to a UFP_D on a USB Type-C connector using a USB Type-C to USB Type-C cable. The 2MΩ pull-downs on SBU1 and SBU2 are representative of the leakage of ESD and EMI/RFI components including termination to ensure no floating nodes, and are intended to show compliance with zSBUTermination in the USB Type-C specification. Note: These schematics do not show the ESD protection and EMI/RFI components typically included in the system designs.

HPD shall be applied to AUX common mode in the USB Type-C UFP_D and derived from AUX common mode in the USB Type-C DFP_D. The 100 kΩ pull-downs at the HPD transmitter and receiver shall be as specified in

DisplayPort 1.3. Note that the effect of the AUX terminations on the HPD signal are to significantly slow the HPD rise and fall times as seen at the HPD receiver. This in turn may have the effect of shortening an IRQ_HPD low

pulse by up to 35%. Implementers are advised to ensure that the detection of an IRQ_HPD pulse meets the 0.25 msec requirement in DisplayPort 1.3, section 5.1.4.

The plug orientation switch may be replaced by AUX polarity inversion logic in the DisplayPort transmitter or the DisplayPort receiver, controlled by the plug orientation detection mechanism associated with the USB Type-C receptacle.

Note that the 3.3V levels in the adapters are derived from VCONN, as not all Legacy DisplayPort UFP_D devices provide DP_PWR.

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660 Figure 3-1 AUX and HPD Signaling using USB Type-C to USB Type-C cable assemblies

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Figure 3-2 shows the system design of a DFP_D on a USB Type-C connector connected to a UFP_D on a Legacy DisplayPort connector using a USB Type-C to Legacy DisplayPort adapter. Note that during the Discovery Process switches S1 and S2 are open, but once connection to a Legacy DisplayPort UFP_D has been discovered, the AUX pull-up/downs that emulate a Legacy DisplayPort DFP_D on the AUX single ended connections are engaged by closing switches S1 and S2.

Care should be taken in the system design of the Legacy DisplayPort DFP_D/UFP_D Connect Detect logic to be able to detect the weak (nominal 1MΩ pull-up) on AUX+ in the Legacy DisplayPort UFP_D, bearing in mind the system leakage that may be present in the connected Legacy DisplayPort UFP_D due to its ESD and EMI components. The 470kΩ resistor represents a compromise between providing an adequate pull-down to overcome these losses and the need for a relatively low threshold for the connection detection that this requires. Actual values will depend on the specific system design. The very weak (4.7MΩ) resistor on AUX- represent circuitry required to avoid a floating

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conductor when the adapter is not connected to a Legacy DisplayPort UFP_D without compromising the threshold in the Legacy DisplayPort UFP_D used to detect the adapter’s pull-up. HPD shall be applied to AUX common mode in the cable adapter.

Equivalent implementations to the one illustrated are permissible, for example, an implementation in which the HPD signal is regenerated by the HPD detection logic in the USB Type-C to Legacy DisplayPort adapter.

Figure 3-2 AUX and HPD Signaling using USB Type-C to Legacy DisplayPort Adapters

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Figure 3-3 shows the system design of a DFP_D on a Legacy DisplayPort connector connected to a UFP_D on a USB Type-C connector using a Legacy DisplayPort to USB Type-C adapter. Note that the AUX pull-up/downs that are used to emulate a Legacy DisplayPort DFP_D on the AUX single-ended signals are disengaged in the adapter by

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opening switches S1 and S2. Note also that this adapter is the same adapter as is used in the previous example, but that DisplayPort signaling is flowing in the opposite direction.

HPD shall be summed from the AUX common mode in the cable adapter.

Equivalent implementations to the one illustrated are permissible, for example, an implementation in which the HPD signal is detected on the AUX common mode and regenerated as a single-ended signal towards the Legacy DisplayPort connector.

Figure 3-3 AUX and HPD Signaling using Legacy DisplayPort to USB Type-C Adapters

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3.16 Legacy DisplayPort Connector CONFIG1 and CONFIG2 pins

The CONFIG1 and CONFIG2 pins on the Legacy DisplayPort plug in the USB Type-C to Legacy DisplayPort adapters shall each be pulled low by means of a 1MΩ resistor to GND. Section 4.5 describes the connection of CONFIG1 and CONFIG2 for a Legacy DisplayPort receptacle adapter to a legacy Multi-Function dock. Note that DisplayPort Dual-Mode Cable Adapters are not supported on the USB Type-C to Legacy DisplayPort adapter’s Legacy DisplayPort Connector.

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4 USB Type-C Cable Assemblies used for DisplayPort

All associations of USB Type-C functions with specific pins on the USB Type-C connector are informative. Reference should be made to USB Type-C for normative USB pin functionality.

4.1 Scenario 1 USB Type-C Full-Featured Cable Assembly

Figure 4-1 shows an example of a USB Type-C full-featured standard cable assembly (as defined in the USB Type-C specification), used for DisplayPort. DisplayPort signaling speeds are as for USB Gen 2 (10.0 Gbps) or as specified in DisplayPort (passive cables only). Multi-Function (DisplayPort and USB Enhanced SuperSpeed simultaneously) is supported.

Figure 4-1 Scenario 1

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4.1.1 Scenario 1 USB Type-C Full-Featured cable Assembly using GEN2_BR

Figure 4-2 illustrates the DisplayPort usage of the signal connections in the USB Type-C Full-Featured standard cable assembly, when the plugs at both ends are inserted in normal orientation. This scenario uses DFP_D pin Assignment A at the DisplayPort Source and UFP_D pin Assignment A at the DisplayPort Sink. Note: This figure omits the USB-PD Identification Circuitry that is incorporated in the cable assembly.

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Figure 4-2 Scenario 1 GEN2_BR Cable Assembly Wiring

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4.1.2 Scenario 1 USB Type-C Full-Featured cable Assembly using DP_BR

Figure 4-2 illustrates the DisplayPort usage of the signal connections in the USB Type-C Full-Featured standard cable assembly, when the plugs at both ends are inserted in normal orientation. This scenario uses DFP_D pin Assignment C at the DisplayPort Source and UFP_D pin Assignment C at the DisplayPort Sink. Note: This figure omits the USB-PD Identification Circuitry that is incorporated in the cable assembly.

Figure 4-3 Scenario 1 DP_BR Cable Assembly Wiring

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4.2 Scenarios 2a and 2b USB Type-C to Legacy DisplayPort Cable Assemblies

4.2.1 Scenario 2a USB Type-C DFP_D to Legacy DisplayPort UFP_D

Figure 4-4 shows a USB Type-C plug to Legacy DisplayPort plug cable assembly. Signaling speeds are as per DisplayPort 1.3.

Figure 4-4 Scenario 2a

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Figure 4-5 and Table 4-1 illustrates the DisplayPort usage of the signal connections in the USB Type-C DFP_D to Legacy DisplayPort UFP_D cable assembly, when the USB Type-C plug is inserted in normal orientation. This scenario uses DFP_D pin Assignment E at the DisplayPort Source. The pin numbering on the Legacy DisplayPort connector is that for the full size Legacy DisplayPort connector. See Table 4-1 for pin numbering for the Legacy Mini DisplayPort connector.

Note: This figure omits the pull-downs on CONFIG1 and CONFIG2.

Figure 4-5 Scenario 2a Cable Assembly Wiring

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741 Table 4-1 USB Type-C DFP_D to Legacy DisplayPort UFP_D Usage

USB Type-C Plug #1 –DFP_D Pin A1, B1, A12, B12 A4, B4, A9, B9 A5 A6 A7 A2 A3 B11 B10 B2 B3 A11 A10 A8 B8 B5 Shell (DP) Signal Name GND Wire Number 1 [16] Wire Signal Name GND_PWRrt1 [GND_PWRrt2] Legacy DisplayPort/ Legacy mini DisplayPort Plug UFP_D DP Pin 2, 5, 8, 11, 16, 19 13 14 6 4 3 1 9 7 12 10 15 17 18 20 Shell mDP Pin 1, 7, 8, 13, 14, 19 4 6 11 9 5 3 17 15 12 10 16 18 2 20 Shell (DP) Signal Name GND VBUS CC Dp1 Dn1 ML2+ ML2- ML3+ ML3- ML1+ ML1- ML0+ ML0- AUX_P/HPD AUX_N/HPD VCONN Shield 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Braid Powers USB Billboard Cable logic (PD) Cable logic (USB Billboard) Cable logic (USB Billboard) 1M to GND 1M to GND SDPp1 SDPn1 SDPp2 SDPn2 SDPp3 SDPn3 SDPp4 SDPn4 Cable logic Cable logic Cable logic Powers Cable logic n.c Shield CONFIG1 CONFIG2 ML2+ ML2- ML3+ ML3- ML1+ ML1- ML0+ ML0- AUX_P AUX_N HPD DP_PWR Shield 742 743 744 745 746 747 748 749

The cable assembly shall contain logic to implement USB-PD and support the Discovery Process (see Section 5). The cable assembly contains a USB Billboard device, which the PD logic shall connect to D+/D- in the event that a switch to the use of DisplayPort as an Alternate Mode is not successful. The connections in the cable assembly behind pins A10, A11, B11 and B10 on the USB Type-C plug shall contain series AC capacitors as specified in DisplayPort 1.3 (75nF – 200nF), as these pins are required to be AC coupled at the DFP_D by the DisplayPort specification but are DC connected in the system behind the USB Type-C receptacle. The series AC capacitors on these pins are also required by the USB Type-C specification.

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4.2.2 Scenario 2b Legacy DisplayPort DFP_D to USB Type-C UFP_D

Figure 4-6 shows a Legacy DisplayPort plug to USB Type-C plug cable assembly. Signaling speeds are as per DisplayPort 1.3.

Figure 4-6 Scenario 2b

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Figure 4-7 and Table 4-2 illustrate the DisplayPort usage of the signal connections in the Legacy DisplayPort

DFP_D to USB Type-C UFP_D cable assembly, when the USB Type-C plug is inserted in normal orientation. This scenario uses UFP_D pin Assignment E. The cable assembly is the same cable assembly as is used in Scenario 2a, but with the DisplayPort signaling running in the opposite direction. The pin numbering on the Legacy DisplayPort connector is that for the full size Legacy DisplayPort connector. See Table 4-2 for pin numbering for the Legacy Mini DisplayPort connector.

Figure 4-7 Scenario 2b Cable Assembly Wiring

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763 Table 4-2 Legacy DisplayPort DFP_D to USB Type-C UFP_D Usage

Legacy DisplayPort/ Legacy mini DisplayPort Plug DFP_D (DP) Signal Name GND USB Type-C Plug Wire Signal Name GND_PWRrt1 [GND_PWRrt2] UFP_D (DP) Signal Name GND DP Pin 2, 5, 8, 11, 16, 19 13 14 6 4 3 1 9 7 12 10 15 17 18 20 Shell mDP Pin 1, 7, 8, 13, 14, 19 4 6 11 9 5 3 17 15 12 10 16 18 2 20 Shell Wire Number 1 [16] Pin A1, B1, A12, B12 A4, B4, A9, B9 A5 A6 A7 A2 A3 B11 B10 B2 B3 A11 A10 A8 B8 B5 Shell CONFIG1 CONFIG2 ML1- ML1+ ML0- ML0+ ML2- ML2+ ML3- ML3+ AUX_P AUX_N HPD DP_PWR Shield Powers USB Billboard Cable logic (PD) Cable logic (USB Billboard) Cable logic (USB Billboard) 1M to GND 1M to GND SDPp1 SDPn1 SDPp2 SDPn2 SDPp3 SDPn3 SDPp4 SDPn4 Cable logic Cable logic Cable logic Powers Cable logic n.c Shield 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Braid VBUS CC Dp1 Dn1 ML1- ML1+ ML0- ML0+ ML2- ML2+ ML3- ML3+ AUX_P/HPD AUX_N/HPD VCONN Shield 7 765 766

Pins A10, A11, B11 and B10 are DC coupled in the system behind the USB Type-C receptacle, so the capacitors on these pins provide the optional AC coupling permitted by the DisplayPort 1.3 specification.

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4.2.3 USB Type-C to Legacy DisplayPort Cable Assembly electrical properties

The electrical specification of the Cable Assembly is based on the specification methodology for USB Type-C to USB Type-C Passive Cable Assemblies (section 3.7.3 in the USB Type-C specification).

4.2.3.1 Intra-pair skew (Informative)

The intra-pair skew should be limited to 30ps. This is designed to support 2m cables at 15ps per meter.

4.2.3.2 Insertion Loss Fit at Nyquist Frequencies

The insertion loss fit at Nyquist frequency (ILfitatNq) shall meet the following requirements:

  

>= -5.5dB at 1.35GHz >= -8.5dB at 2.7GHz >= -11.0dB at 4.05GHz

1.35GHz, 2.7GHz and 4.05 GHz are the Nyquist frequencies for HBR, HBR2 and HBR3 respectively. Figure 4-8 illustrates the ILfit curves for the three DisplayPort transmission rates

Figure 4-8 ILfit at HBR, HBR2 and HBR3

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4.2.3.3 Integrated Multi-reflection

For the Input Pulse Spectrum (used in the calculation of IMR), the DisplayPort bit rates correspond to a UI of 370.4ps, 185.2ps and 123.5ps respectively. The rise time is 0.4 UI.

IMR has dependency on ILfitatNq. More IMR may be tolerated when ILfitatNq decreases. The IMR limit is specified as a function of ILfitatNq:

𝐼𝑀𝑅 ≤0.0579∙𝐼𝐿𝑓𝑖𝑡𝑎𝑡𝑁𝑞2+1.∙𝐼𝐿𝑓𝑖𝑡𝑎𝑡𝑁𝑞−30.23

Figure 4-9 shows the compensation curve of IMR versus ILFitatNq at HBR3.

Figure 4-9 IMR versus ILfit at HBR3

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4.2.3.4 Power Summed Integrated Crosstalk between DP Lanes

The power sum limits for integrated crosstalk between the DisplayPort lanes shall comply with the following limits:

IFEXT <= -35 dB (up to 12 GHz)

INEXT <= -35dB (up to 12 GHz) when measured through the USB Type-C connector INEXT <= -33dB (up to 12 GHz) when measured through the Legacy DisplayPort connector

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796 IRL has a strong dependency on ILfitatNq, and its limit is specified as a function of ILfitatNq:

797 𝐼𝑅𝐿 ≤0.0336∙𝐼𝐿𝑓𝑖𝑡𝑎𝑡𝑁𝑞2+1.28∙𝐼𝐿𝑓𝑖𝑡𝑎𝑡𝑁𝑞−10.87

798 Figure 4-10 shows the compensation curve of IRL versus ILFitatNq at HBR3.

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Figure 4-10 IRL versus ILfit at HBR3

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SCD12/SCD21 shall be <= -17 dB from 100 MHz to 8.1 GHz.

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4.2.4 USB Type-C to Legacy DisplayPort Cable Assembly functionality

The Cable Assembly includes logic to perform the following functions

4.2.4.1 Support of USB-PD

The logic supports the USB-PD protocol in the role of a UFP_U, negotiates a power contract, and responds to PD Commands for the discovery of DisplayPort Mode capability, entry and exit by the connected DFP_U using Structured Vendor Defined Messages as specified in USB-PD and USB Type-C. The logic reports whether the

Legacy DisplayPort connector is disconnected, connected to a Legacy DisplayPort DFP_D or connected to a Legacy DisplayPort UFP_D.

4.2.4.2 Legacy DisplayPort DFP_D/UFP_D detection

The cable assembly shall contain logic to detect the presence of a connected Legacy DisplayPort DFP_D or a connected Legacy DisplayPort UFP_D, and shall report the status that the Legacy DisplayPort connector is

disconnected, connected to a Legacy DisplayPort DFP_D, or connected to a Legacy DisplayPort UFP_D by means of messaging on USB-PD. The adapter shall report a change of state between these three states by means of messaging on USB-PD.

The following description outlines a method by which connection detection can be performed. Any implementation with equivalent behavior may be used.

The DisplayPort 1.3 specification defines pull-up and pull-down resistors for the AUX[P,N] pair at both Legacy DisplayPort DFP_D and Legacy DisplayPort UFP_D, between the AC coupling capacitors. This implementation

allows a Legacy DisplayPort UFP_D to determine when a Legacy DisplayPort DFP_D has been connected. Table 4-3 illustrates the use of the pull-up and pull-down resistors.

Table 4-3 Legacy DisplayPort Connector AUX states

AUX_P AUX_N Legacy DisplayPort DFP_D 100 kΩ to GND 100 kΩ to 3.3V Legacy DisplayPort UFP_D 1 MΩ to 3.3V 1 MΩ to GND Logic value when connected 0 1 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845

The Legacy DisplayPort connector in the adapter must be able to be configured as either a Legacy DisplayPort DFP_D or a Legacy DisplayPort UFP_D, so the design includes analog switches (S1 and S2) in series with the 100 kΩ resistors. In general, the switches must be closed when a Legacy DisplayPort UFP_D is connected, i.e. the

Legacy DisplayPort connector (and therefore the USB Type-C system) represents a Legacy DisplayPort DFP_D, and open when a Legacy DisplayPort DFP_D is connected and the Legacy DisplayPort connector (and therefore the USB Type-C system) represents a Legacy DisplayPort UFP_D. Example schematics are given in section 3.15. Disabling the 100 kΩ resistors means that a non-connected adapter creates a floating AUX bias between the AC coupling caps (and therefore an unknown logic state). To avoid this, a very weak (4.7 MΩ) pull-down resistor is added to AUX- pair. A weak (470 kΩ) pull-down is used on AUX+ as part of the Legacy DisplayPort UFP_D detection mechanism.

After filtering to generate AUX logic states while ignoring actual AUX channel traffic and filtering HPD to avoid an IRQ-HPD being detected as a disconnect, the state of the Legacy DisplayPort connector may be determined. The adapter places HPD in high impedance and initially disconnects the 100 kΩ resistors (by opening S1 and S2).. A powered Legacy DisplayPort DFP_D always has a pull-up on AUX_N. Thus, given that the adapter’s pull-up on AUX_N is disabled, a logic 1 on AUX_N indicates a connected Legacy DisplayPort DFP_D. If the adapter detects a connected Legacy DisplayPort DFP_D, then it reports the presence of the connected Legacy DisplayPort DFP_D to the USB Type-C system over PD and awaits a Command from the USB Type-C system to switch into UFP_D

configuration. On receipt of this Command, the adapter closes the SBU isolation switches, thus asserting HPD on the Legacy DisplayPort connector towards the Legacy DisplayPort DFP_D.

A powered Legacy DisplayPort UFP_D will provide the weak pull-up on AUX_P. Some legacy displays don’t provide this pull-up, but assert HPD without Legacy DisplayPort DFP_D detection. Thus, given that the adapter’s pull-down on AUX_P is disabled, either a logic 1 (using a threshold appropriate for the adapter’s weak pull-down on Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED V1, d3

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AUX_P) on AUX_P or HPD indicates a connected Legacy DisplayPort UFP_D. If the adapter detects the presence of a connected Legacy DisplayPort UFP_D, then it enables the 100 kΩ resistors on the Legacy DisplayPort connector. The adapter awaits the assertion of HPD by the connected Legacy DisplayPort UFP_D, and, on sensing HPD, reports the presence of the connected Legacy DisplayPort UFP_D to the USB Type-C system over PD and awaits a

Command from the USB Type-C system to switch into Legacy DisplayPort DFP_D configuration. On receipt of this Command, the adapter closes the SBU isolation switches, thus asserting HPD on the USB Type-C connector towards the USB Type-C DisplayPort DFP_D.

Table 4-4 enumerates the possible states of HPD, AUX_P and AUX_N. Given the appropriate filtering, the adapter may use the various states to determine the state of the connection at any time.

Table 4-4 Legacy DisplayPort Connector HPD and AUX states

HPD 0 0 0 AUX_P 0 0 1 AUX_N 0 1 0 Interpretation Nothing is connected, or a powered down device is connected An external Legacy DisplayPort DFP_D has been connected An external Legacy DisplayPort UFP_D has been connected and is waiting to detect the presence of the Legacy DisplayPort DFP_D (i.e. waiting for the 100 kΩ resistors to be connected). The adapter connects the 100 kΩ resistors Invalid An external Legacy DisplayPort UFP_D has been connected (one that does not implement the 1 MΩ resistors, but asserts HPD directly) Legacy DisplayPort UFP_D is connected and ready. The adapter has already connected the 100 kΩ resistors. Presence of Legacy DisplayPort UFP_D may be reported. This state is maintained until the Legacy DisplayPort UFP_D is disconnected. Invalid (possible transitory state between 0 1 0 and 1 0 1 if the Legacy DisplayPort UFP_D detects a connection resulting from the adapter’s weak pull-down) Invalid (this state may occur if the connected device is a Legacy DisplayPort DFP_D side DP++ adapter with DDC pull-ups). 0 1 1 1 0 0 1 0 1 1 1 1 1 0 1 856 857 858 859

Once the adapter is operating in Legacy DisplayPort UFP_D configuration (i.e. connected to a Legacy DisplayPort DFP_D on the Legacy DisplayPort connector) and passing HPD from the USB Type-C connector to the Legacy DisplayPort connector, the table simplifies to that shown in Table 4-5.

Table 4-5 Legacy DisplayPort Connector HPD and AUX states in adapter UFP_D configuration

HPD 1 1 1 AUX_P 0 0 1 AUX_N 0 1 0 Interpretation A powered-down device is connected Legacy External DisplayPort DFP_D is connected and operational Transitional state when the previously connected Legacy DisplayPort DFP_D is disconnected, the adapter should switch out of Legacy DisplayPort UFP_D configuration and report the new status to the USB Type-C UFP_D, which in turn should disable the Legacy DisplayPort Configuration, isolating the SBU connection and thus de-asserting HP Invalid 1 1 1 Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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4.3 Scenarios 3a and 3c USB Type-C DFP_D to Protocol Converter

Figure 4-11 and Figure 4-12 show a USB Type-C DFP_D to protocol converter adapters. Signaling speeds are as per DisplayPort 1.3.

Figure 4-11 Scenario 3a

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Figure 4-12 Scenario 3c

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This scenario uses DFP_D pin Assignment C. The implementation of AUX signaling and HPD in the protocol converter is the same as is used in a USB Type-C UFP_D, see section 3.15.

4.3.1 HDMI Protocol Converter Adapters

HDMI protocol adapters shall comply with the requirements for DP to HDMI Protocol Converter Adaptors specified in DisplayPort 1.3.

In addition, DETAILED_CAP_INFO_AVAILABLE in the DPCD register DOWNSTREAM_PORT_PRESENT (DPCD register 00005h) shall have value 1 (i.e. that the DFP_D capability fields in DPCD registers starting at 00080h use the longer four byte format.).

The following features, optional in the DisplayPort 1.3 specification, shall be supported.

          

594 M characters per second per channel 4K@60 YCbCr 4:4:4 as specified in HDMI 2.0. HDMI Sink max character per channel rate indication HDMI Sink Error Status

CEC, including low power management Passthru of YCbCr 4:2:0 color format

Conversion from YCbCr 4:4:4 format or YCbCr 4:2:2 format to YCbCr 4:2:0 Generation of IRQ_HPD on HDMI status changes HDCP 1.4 and HDCP 2.2 on the USB Type-C connection HDCP 1.4 and HDCP 2.2 on the HDMI connection

Conversion from DP Frame Sequential to HDMI Frame Pack 3D format

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

887 888 8 0 1 2 3 4 5 6 7 8 9 900 901 902 903

4.3.1.1 Audio Return Channel

The protocol adapter may include a USB 2.0 bridge Device to convert the Audio Return Channel (ARC) to the USB Audio Device Class (audio input).

Support is optional for the Protocol Adapter, and its support is exposed to the Host as part of the Service Abstraction defined in DisplayPort 1.3. The Source policy may or may not support CEC.

Note that CEC support is a pre-requisite for ARC for both the protocol adapter and the Source. Note that ARC is only supported on Sources that are also USB Hosts.

4.3.2 VGA Protocol Converter Adapters

VGA protocol adapters shall support a minimum resolution of 1920 x 1200 @60Hz, 24 bpp reduced blanking, 1600 x 1200 @60Hz, 24 bpp full blanking. VGA protocol adapters shall support at least two lanes of HBR and at least one lane of HBR2, but are not required to support bandwidths in excess of two lanes of HBR/one lane of HBR2.

4.3.3 DVI Protocol Converter Adapters

Single link DVI protocol adapters shall support a minimum resolution of 1920 x 1200 @60Hz, 24 bpp. DVI protocol adapters shall support two lanes of HBR, but are not required to support bandwidths in excess of two lanes of HBR.

4.4 Scenario 4a USB Type-C DFP_D to a Multi-Function Dock (MF Dock)

Figure 4-13 shows a USB Type-C DFP_D connected to a Multi-Function dock

Figure 4-13 Scenario 4a

904 905 906 907 908 909 910 911 912 913 914

4.4.1 Scenario 4a USB Type-C Full-Featured Cable Assembly using GEN2_BR Multi-Function

Figure 4-14 illustrates the DisplayPort usage of the signal connections in the USB Type-C Full-Featured standard cable assembly, when the plugs at both ends are inserted in normal orientation. This scenario uses DFP_D pin

Assignment B at the DisplayPort Source and UFP_D pin Assignment B at the DisplayPort Sink. In the event that the Multi-Function Dock can be configured to apply all four DisplayPort lanes to the DisplayPort connector, then pin Assignment A is used when the dock is configured to operate in this configuration. Note that the Multi-Function dock must contain a DisplayPort Branch device that can adapt from GEN2_BR to DP_BR on the Legacy DisplayPort connector.

Note: This figure omits the USB-PD Identification Circuitry that is incorporated in the cable assembly.

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

915 916

Figure 4-14 Scenario 4a GEN2_BR MF Cable Assembly Wiring

917 918 919 920 921 922

4.4.2 Scenario 4a USB Type-C Full-Featured Cable Assembly using DP_BR Multi-Function

Assignment D at the DisplayPort Source and UFP_D pin Assignment D at the DisplayPort Sink. In the event that the

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

923 924 925 926 927

Multi-Function Dock can be configured to apply all four DisplayPort lanes to the DisplayPort connector, then pin Assignment C is used when the dock is configured to operate in this configuration.

Note: This figure omits the USB_PD Identification Circuitry that is incorporated in the cable assembly.

Figure 4-15 Scenario 4a DP_BR MF Cable Assembly Wiring

928

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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4.5 Scenario 4b USB Type-C DFP_D to a VESA DockPort adapter

Figure 4-16 shows a USB Type-C DFP_D connected to a dock, as defined in the VESA DockPort specification, via a Legacy DockPort receptacle adapter.

Figure 4-16 Scenario 4b

933 934 935 936 937 938

The adapter has additional functionality compared to the USB Type-C to DP cable assemblies to support DockPort discovery and to connect CONFIG1/2 to the USB 2.0 signals from the Host via a hub. This scenario uses DFP_D pin Assignment F at the DisplayPort Source. Note, DFP_D pin Assignment E is used in the case that the DockPort is in the mode that is supporting four lanes of DisplayPort.

Figure 4-17 Scenario 4b Legacy DockPort Receptacle Adapter Wiring

939

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940 Table 4-6 USB Type-C DFP_D to Legacy DockPort Receptacle

USB Type-C Plug – DFP_D (DP) Signal Name GND Wire Number 1 [16] Wire Signal Name GND_PWRrt1 [GND_PWRrt2] Legacy DisplayPort/mini DisplayPort Receptacle DFP_D DP Pin 2, 5, 8, 11, 16, 19? 13 14 7 9 10 12 1 3 4 6 15 17 18 20 Shell mDP Pin 1, 7, 8, 13, 14, 19 4 6 15 17 10 12 3 5 9 11 16 18 2 20 Shell (DP) Signal Name GND Pin A1, B1, A12, B12 A4, B4, A9, B9 A5 A6 A7 A2 A3 B11 B10 B2 B3 A11 A10 A8 B8 B5 Shell VBUS CC Dp1 Dn1 SSTXp1 SSTXn1 SSRXp1 SSRXn1 ML1+ ML1- ML0+ ML0- AUX_P/HPD AUX_N/HPD VCONN Shield 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Braid Powers USB Billboard Cable logic (PD) Cable logic (USB Billboard)/Dp1 Cable logic (USB Billboard)/Dn1 SDPp1 SDPn1 SDPp2 SDPn2 SDPp3 SDPn3 SDPp4 SDPn4 Cable logic Cable logic Cable logic Cable logic n.c Shield CONFIG1 CONFIG2 SSTXp1 SSTXn1 SSRXp1 SSRXn1 ML0+ ML0- ML1+ ML1- AUX_P AUX_N HPD DP_PWR Shield 941 942 943

The electrical performance of the USB Type-C to DockPort Receptacle adapter shall meet the requirements for Resizing Adapters given in DisplayPort 1.3 section 4.1.5.

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

944 945 946 947

4.6 Scenarios 4c/d USB Type-C DFP_D to Multi-Function cradle/captive cable dock

Figure 4-18 shows a USB Type-C DFP_D connected to a Multi-Function cradle dock.

Figure 4-18 Scenario 4c

948 949 950

Figure 4-19 shows a USB Type-C DFP_D connected to a Multi-Function captive cable dock.

Figure 4-19 Scenario 4d

951 952 953 954 955

4.6.1 Scenarios 4c/d USB Type-C DFP_D to Multi-Function cradle dock using GEN2_BR Multi-Function

This scenario uses DFP_D pin Assignment B at the DisplayPort Source. In the event that the Multi-Function Dock can be configured to apply all four DisplayPort lanes to the Legacy DisplayPort connector, then pin Assignment A is

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

956 957 958

used when the dock is configured to operate in this configuration. Note that the Multi-Function dock must contain a DisplayPort Branch device that can adapt from GEN2_BR to DP_BR on the Legacy DisplayPort connector.

Table 4-7 USB Type-C Cable Assembly DisplayPort Usage (MF cradle/captive cable dock) GEN2_BR

USB Type-C Plug DFP_D Pin Signal Name A1, B1, A12, B12 GND A4, B4, A9, B9 VBUS A5 CC A6 Dp1 A7 Dn1 A2 SSTXp1 A3 SSTXn1 B11 SSRXp1 B10 SSRXn1 B2 ML0+ B3 ML0- A11 ML1+ A10 ML1- A8 AUX_P/HPD B8 AUX_N/HPD B5 VCONN Shell Shield Proposed DisplayPort Alt Mode on USB Type-C

959 960 961 962 963 9

4.6.2 Scenario 4c/d USB Type-C DFP_D to Multi-Function cradle/captive cable dock using DP_BR Multi-Function

This scenario uses DFP_D pin Assignment D at the DisplayPort Source. In the event that the Multi-Function Dock can be configured to apply all four DisplayPort lanes to the Legacy DisplayPort connector, then pin Assignment C is used when the dock is configured to operate in this configuration.

Table 4-8 USB Type-C Cable Assembly DisplayPort Usage (MF cradle/captive cable dock) DP_BR

USB Type-C Plug DFP_D Pin Signal Name A1, B1, A12, B12 GND A4, B4, A9, B9 VBUS A5 CC A6 Dp1 A7 Dn1 A2 SSTXp1 A3 SSTXn1 B11 SSRXp1 B10 SSRXn1 B2 ML1+ B3 ML1- A11 ML0+ A10 ML0- A8 AUX_P/HPD B8 AUX_N/HPD B5 VCONN Shell Shield 965

Proposed DisplayPort Alt Mode on USB Type-C

966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 9 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003

5 Discovery and USB-PD

All descriptions of USB-PD signaling are informative. Reference should be made to USB-PD for normative USB-PD functionality.

5.1 Connection discovery

A system supporting a DFP_D on a USB Type-C receptacle shall either implement a USB DFP (with Rp pull-up on CC1/CC2 for connection discovery) or shall implement a USB DRP (able to assert Rp pull-up on CC1/CC2

periodically) or shall implement a USB UFP with Accessory Support. After USB Type-C Discovery, all these ports are described in this specification as DFP_U. A system supporting a UFP_D on a USB Type-C receptacle shall implement a USB DRP (able to assert Rp pull-up on CC1/CC2 periodically) or shall implement a USB UFP with Accessory Support. After USB Type-C Discovery, both of these ports are described in this specification as USB_U. Note, a USB UFP with Accessory Support is not required to operate as a USB Host when it asserts Rp and discovers a DisplayPort capable UFP.

If either or both of the connected systems are USB DRPs, then they resolve into one being USB DFP and one being USB UFP on first connection. Note that they may exchange roles using a DR_Swap USB-PD message. The roles are static (DFP_U or UFP_U) during the time that DisplayPort discovery and DisplayPort Mode is used.

If a DR_Swap message is issued during DisplayPort discovery, then the current USB DFP abandons the Discovery Process and the new USB DFP initiates a new Discovery Process. The new USB DFP is described as DFP_U in this specification, and the new USB UFP is described as UFP_U in this specification.

A system supporting DisplayPort on a USB Type-C plug shall implement a USB UFP, with Rd pull-down on CC. The system may be self-powered, in which case it shall present zOPEN on VCONN, or may be VCONN-Powered Accessory, as specified in the USB Type-C specification, in which case it shall present Ra on VCONN. If it is a VCONN-Powered Accessory, then it is strongly recommended for the Accessory to reduce the power consumption through Ra once it detects that VCONN is provided. The system shall support BMC PD signaling on CC.

The system supporting DisplayPort on a USB Type-C receptacle that is also the DFP_U (including a USB UFP with Accessory Support that has detected a Powered Accessory) provides VCONN if it detects Ra on the CC1/2 pin not being used for PD communications.

5.2 DisplayPort Mode discovery and entry/exit

Discovery of support for DisplayPort and entry/exit into DisplayPort Mode shall be performed using USB-PD

messages as described in the Discovery Process defined in the USB-PD and the USB Type-C specifications. These shall be augmented for the specific case of DisplayPort as described in this section.

The 16-bit USB Standard ID assigned by the USB-IF to DisplayPort (0xFF01) is denoted in this section by DP_SID. Only a receptacle-based DFP_U supporting DisplayPort may act as an Initiator for the USB-PD messages related to the DisplayPort Alternate Mode, apart from the Attention Command, which may only be issued by the UFP_U (which may be receptacle based or plug based). Note, this specification does not support plug-based DFP_Us.

5.2.1 Structured VDM Header

The Structured VDM Header as specified in USB-PD shall be used for the DisplayPort specific Commands, i.e. DisplayPort Status Update and DisplayPort Configure, in conjunction with DP_SID. Table 5-1 is reproduced from Table 6-19 of USB-PD but updated to show the additional DisplayPort specific Commands.

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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Bit(s) B31..16 Table 5-1 VDM Message Header

Description Standard or Vendor ID Values Base SID (for Discover SVIDs Command) or DP_SID, a 16-bit unsigned integer, assigned by the USB-IF 1 = Structured VDM Version 1.0 = 0 Values 1-3 are reserved B12..11 B10..8 Reserved Object Position (000b reserved) 001b..110b = Index into the list of VDOs to identify the desired Mode VDO 111b = Exit all Modes (equivalent of a power on reset). Shall not be used with the Enter Mode Command B7..6 Command Type Initiator shall set to zero 00 = Initiator 01 = Responder ACK 10 = Responder NAK 11 = Responder BUSY 0 = Reserved, shall not be used 1 = Discover Identity 2 = Discover SVIDs 3 = Discover Modes 4 = Enter Mode 5 = Exit Mode 6 = Attention 7-15 = Reserved, shall not be used 16 = DisplayPort Status Update 17 = DisplayPort Configure 18-31 = Reserved for DP_SID Use B15 B14..13 VDM Type Structured VDM Version B5 B4..0 Reserved Command 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015

The UFP_U may support SVIDs other than the DisplayPort SVID, in which case the UFP_U may present them in an arbitrary order in its response. The DFP_U shall search all the SVIDs returned so as to discover the DP_SID. The UFP_U may support a DFP_D, a UFP_D, or both. An example of supporting both is a USB Type-C to Legacy DisplayPort adaptor cable, which is required to be reversible. The UFP_U when it sends the Responder Discover Modes VDM shall indicate its DisplayPort capabilities in the VDO as specified in Table 5-2.

Future versions of this specification may describe other Modes associated with DP_SID. Such Modes will be

identified by having a non-zero value in B31-24 of the VDO. The DFP_U shall examine the list of Modes returned until it finds zeros in B31-24 of the VDO and a non-zero value in B23-0 of the VDO (i.e. DisplayPort capabilities). The DFP_U and UFP_U shall use the corresponding offset (indexed from 1) in the Enter Mode, DisplayPort Configure, DisplayPort Status Update, Attention and Exit Mode Commands.

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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Bit(s) B31..24 B23..16 Table 5-2 DisplayPort capabilities

Description Values Reserved (always 0) 00000000 = UFP_D pinouts not supported xxxxxxx1 = Pinout A supported xxxxxx1x = Pinout B supported (1) xxxxx1xx = Pinout C supported xxxx1xxx = Pinout D supported (1) xxx1xxxx = Pinout E supported xx1xxxxx = Reserved x1xxxxxx = Reserved 1xxxxxxx = Reserved B15..8 DFP_D Pin Assignments supported 00000000 = DFP_D pinouts not supported xxxxxxx1 = Pinout A supported xxxxxx1x = Pinout B supported (1) xxxxx1xx = Pinout C supported xxxx1xxx = Pinout D supported (1) xxx1xxxx = Pinout E supported xx1xxxxx = Pinout F supported (1) x1xxxxxx = Reserved 1xxxxxxx = Reserved B7 USB 2.0 signaling not used 0 = USB 2.0 signaling may be required on A6/A7 or B6/B7 while configured to DisplayPort 1 = USB 2.0 signaling not required on A6/A7 or B6/B7 while configured to DisplayPort B6 Receptacle indication 0 = DisplayPort interface is presented on a USB Type-C plug 1 = DisplayPort interface is presented on a USB Type-C receptacle B5..2 Signaling for transport of DisplayPort protocol xxx1 = Supports DisplayPort 1.3 signaling rates and electrical specification (shall always be set apart from diagnostic purposes). xx1x = Supports USB Gen 2 signaling rate and electrical specification x1xx = Reserved 1xxx = Reserved B1..0 Port capability 00 = Reserved 01 = UFP_D capable (including Branch Device) 10 = DFP_D capable (including Branch Device) 11 = Both DFP_D and UFP_D capable UFP_D Pin Assignments supported 1017 1018 1019 1020 1021 1022 1023 1024 1025

Note 1: A system supporting DisplayPort on a USB Type-C connector that supports Multi-Function operation (i.e. supports the simultaneous transmission of USB SuperSpeed signaling and DisplayPort signaling) shall offer both the Multi-Function pinout and the associated DisplayPort only pinout. The associated DisplayPort only pinout is

identified by the previous letter, e.g. Pinout D for Multi-Function and Pinout C for DisplayPort only. It shall offer both pinouts even if it only supports one or two lanes of DisplayPort signaling.

The DFP_U shall ensure that the capabilities of the UFP_U are consistent with its own capabilities, taking care to note that a UFP_U that uses a USB Type-C Plug describes the pinouts supported of the corresponding receptacle (i.e. a UFP_D will describe the DFP_D pinouts to which it connects), whereas a UFP_U that uses a USB Type-C

Receptacle describes its pinouts directly (i.e. a UFP_D will describe its own UFP_D pinouts). In general the DFP_U Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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will select a pin Assignment for its USB Type-C receptacle (one of A-F) and configure the port partner with the same pin Assignment (same identifying letter).

An adapter may require more than the USB Type-C level of power on VCONN in order to fully power its DisplayPort functionality. The DFP_U shall ensure that the power VCONN power specified in this specification is available prior to issuing an Enter Mode command addressed to DP_SID. The adapter shall not exceed the USB Type-C specified level of power consumption on VCONN prior to receiving an Enter Mode Command addressed to DP_SID.

5.2.2 DisplayPort Enter Mode

The Enter Mode Command/Exit Mode Command pair addressed to the DisplayPort SVID act as brackets for the various other DisplayPort Mode specific Commands, which may only be issued during the time that DisplayPort Mode is established.

On receiving the Responder ACK in a response to the Enter Mode Command, the DFP_U proceeds to the next step towards configuring the port by sending a DisplayPort Status Update Command to the UFP_U. If the UFP_U responds to the Enter Mode VDM with a Responder NAK, the Mode is not entered and the UFP_U shall expose a USB Billboard device. The UFP_U is not allowed to return a Responder BUSY .

Once the DisplayPort Mode is entered, the DFP_U and UFP_U shall remain in that Mode until one of the three following events occur:

1. The Exit Mode Command is successful 2. A Hard Reset occurs on PD 3. The device is disconnected

An adapter may consume power from VCONN up to the limit specified in section 6.1 after receiving an Enter Mode Command addressed to the DisplayPort SVID and selecting the DisplayPort mode.

A UFP_U may transmit a USB-PD Attention Command at any time once in DisplayPort Mode, and shall do so whenever its status changes.

5.2.3 DisplayPort Status Update

The DFP_U may send a Status Update Command at any time, and generally will do so immediately after receiving the Responder ACK in response to a DisplayPort Enter Mode Command. The DFP_U provides its latest DisplayPort Status in the VDO. The UFP_U replies by in turn transmitting its DisplayPort Status in the VDO. The UFP_U is not allowed to return a Responder NAK. There is no requirement for the UFP_U to carry out any specific behavior based on the information that it receives concerning the DFP_U’s status, and any use that it makes of this information is implementation specific. However, this information may be useful for diagnostic purposes.

A DFP_U or UFP_U that integrates a DFP_D or a UFP_D shall set the appropriate connected status flag permanently to 1. A DFP_U or UFP_U that integrates both a DFP_D and a UFP_D shall set both of the appropriate connected status flags permanently to 1.

In order to resolve the direction of DisplayPort signaling when two systems both capable of acting as both a DFP_D and as a UFP_D are connected together, vendor-dependent means of disabling one or other function shall be

provided, and, when this is done, the respective system shall issue an updated DisplayPort Status Update Command with only the DFP_D Connected or UFP_D Connected bit set, as appropriate. Table 5-3 shows the DisplayPort Status as transmitted in the VDO.

Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

Bit(s) B31..7 B6 Table 5-3 DisplayPort Status

Description Values Reserved (always 0) 0 = maintain current Mode 1 = request exit from DisplayPort Mode (if in DisplayPort Mode) B5 USB Configuration request 0 = Maintain current configuration 1 = Request switch to USB configuration (if in DisplayPort Configuration) B4 Multi-Function preferred 0 = no preference for Multi-Function 1 = Multi-Function preferred B3 Enabled 0 = Adapter DisplayPort functionality is disabled 1 = Adapter DisplayPort functionality is enabled and operational B2 Power low 0 = Adapter is functioning normally, or is disabled 1 = Adapter has detected low power and has disabled DisplayPort support B1..0 DFP_D/UFP_D Connected 00 = neither DFP_D nor UFP_D connected, or adapter is disabled 01 = DFP_D Connected 10 = UFP_D Connected (1) 11 = Both DFP_D and UFP_D Connected Exit DisplayPort Mode request 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 10 1090 1091 1092

Note 1: an adapter that contains a DisplayPort Branch Device with its DisplayPort receiver connected to the USB Type-C plug shall report UFP_D Connected, regardless of whether or not the Branch Device has DFP_Ds connected.

5.2.4 DisplayPort Configure

The switch to use DisplayPort signaling is controlled using the DisplayPort Configure Command with the VDO containing the details of the requested configuration. A DFP_U may transmit a DisplayPort Configure Command at any time while in DisplayPort Mode. Prior to issuing the Command, the DFP_U shall place the USB Type-C pins that are to be reconfigured to DisplayPort in Safe State (as specified in USB Type-C, i.e. ensure that there is no USB signaling on these pins). The UFP_U may enable DisplayPort signaling immediately upon receipt of this Command. It shall respond to this Command with a Responder ACK once it has ensured that the reconfigured pins are

connected to DisplayPort. Note: the UFP_U may directly connect the reconfigured pins to appropriate DisplayPort functionality (e.g. to pins on a DisplayPort connector, or to a DisplayPort protocol converter device). In this case, there is no reconnection required and the Responder ACK may be issued immediately. On receipt of the Responder ACK to this Command, the DFP_U shall switch the reconfigured pins on its USB Type-C receptacle from Safe State to DisplayPort and shall then connect the SBU pins.

The DFP_U may change the number of DisplayPort lanes that are connected as a result of reconfiguration. In this case, as well as placing any additional USB Type-C pins into Safe State before sending the DisplayPort Configure Command, the DFP_U shall isolate the SBU pins. The DFP_U shall not reconnect the SBU pins until after receiving the Responder ACK and then reconnecting the reconfigured high speed pins. In addition, the DFP_U shall ensure that the SBU pins remain disconnected for a minimum of 5 msec. This enables an implementation to ensure that its DisplayPort transmitter (e.g. GPU) sees an HPD disconnect event (and not an IRQ_HPD).

The DFP_U may switch to USB configuration using the DisplayPort Configure Command with the Select

Configuration field set to USB. Prior to issuing the Command, the DFP_U shall isolate the USB Type-C pins that were previously reconfigured to DisplayPort, including the SBU pins. The DFP_U shall ensure that the SBU pins remain disconnected for a minimum of 5 msec. This enables an implementation to ensure that its DisplayPort transmitter (e.g. GPU) sees an HPD disconnect event (and not an IRQ_HPD). The UFP_U may start to use USB

signaling immediately upon receipt of this Command. It shall respond to this Command with a Responder ACK once it has connected the reconfigured pins to USB where USB functionality on these pins is supported. On receipt of the Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106

Responder ACK to this Command, the DFP_U shall switch the previously reconfigured pins on the USB Type-C receptacle to USB.

The DFP_U shall take into account the capabilities of the UFP_U together with the limitations of the cable

connecting the two systems (in the case of a USB Type-C to USB Type-C cable) when determining the configuration of DisplayPort on the interface and select a configuration that is mutually supported. In the case that multiple configurations are available, the configuration to be selected is a matter of DFP_U policy.

Table 5-4 shows the DisplayPort configurations. The DFP_U shall select one of the signaling rates and

configurations and one pinout for either DFP_D or UFP_D (according to the DFP_U’s role), unless it is switching back to USB configuration, in which both pinouts shall be set to zero.

Note that the setting of appropriate multiplexors to support DisplayPort is associated with DisplayPort Configure Command.

Note that it is not necessary for the DFP_U to exit the DisplayPort Mode in order to change the DisplayPort configuration settings on the interface.

Table 5-4 DisplayPort Configuration

Bit(s) B31..24 B23..16 Description Configure UFP_U with UFP_D Pin Assignment Values Reserved (always 0) 00000000 = Deselect UFP_D Assignments 00000001 = Select Assignment A 00000010 = Select Assignment B 00000100 = Select Assignment C 00001000 = Select Assignment D 00010000 = Select Assignment E All other values reserved B15..8 Configure UFP_U with DFP_D Pin Assignment 00000000 = Deselect DFP_D Assignment 00000001 = Select Assignment A 00000010 = Select Assignment B 00000100 = Select Assignment C 00001000 = Select Assignment D 00010000 = Select Assignment E 00100000 = Select Assignment F All other values reserved B7..6 B5..2 Signaling for transport of DisplayPort protocol Reserved (always 0) 0000 = Signaling unspecified (only used when Select Configuration field is set for USB) 0001 = Select DisplayPort 1.3 signaling rates and electrical settings 0010 = Select Gen 2 signaling rates and electrical specifications all other values = reserved B1..0 Select Configuration 00 = Set configuration for USB 01 = Set configuration for UFP_U as DFP_D 10 = Set configuration for UFP_U as UFP_D 11 = Reserved 1107 1108 1109 1110 1111

A UFP_U supporting DisplayPort on a USB Type-C connector that supports Multi-Function operation (i.e. supports the simultaneous transmission of USB SuperSpeed signaling and DisplayPort signaling) may be instructed by the DFP_U to configure the related DisplayPort signaling-only pin Assignment (i.e. pin Assignment A, C or E). If the UFP_U supports only one or two lanes of DisplayPort, then, when so instructed, it shall ensure that the channels Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131

normally associated with USB SuperSpeed signaling but not being used in this Assignment are in Safe State (as specified in USB Type-C).

The UFP_U shall respond with a Responder NAK in the event that it is unable to switch to the requested configuration. Note: this indicates an error in the DFP_U.

5.2.5 Attention

The Attention VDM is used by a UFP_U to signal to the DFP_U that there has been some change in the UFP_U’s status since last reported. The UFP_U shall report its updated status in the VDO following the header, using the format specified in Table 5-3. See section 5.2.3 for full details of the use of status reporting.

5.2.6 DisplayPort Exit Mode

The Exit Mode Command is used by a DFP_U to instruct the UFP_U to exit the DisplayPort Mode of operation. The DFP_U shall only issue an Exit Mode Command when the port is configured to be operating in the USB

configuration. If the UFP_U receives an Exit Mode Command when in a DisplayPort configuration, it shall switch to USB configuration and then continue with the other actions that it performs on receiving an Exit Mode Command. Note: receipt of an Exit Mode Command while not configured as USB indicates an error in the DFP_U.

The UFP_U that receives the Exit Mode VDM shall return to VCONN default power consumption, and exit the Mode, returning to normal USB operation. It shall then send the Responder ACK response. The device is not allowed to return either a Responder NAK or a Responder BUSY.

After the DFP_U receives the Responder ACK it exits into the state that it enters on a new connection.

Note that the Exit Mode Command may be addressed directly to DP_SID plus the Object Position that identifies the Mode, or may be addressed to DP_SID plus Object Position 111b (Exit All Modes).

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1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145

5.3 VDM Message flows

Figure 5-1 shows the initial actions when a new connection is detected. These include

   

Starting the tAMETimeout timer (see Section 5.1.3 of USB Type-C) at the UFP_U, on expiry of which USB Billboard is connected if VBUS is being received;

Determining the cable or adapter properties by using Discover Identity addressed to SOP’;

Negotiating a PD Contract: mandatory, but for simple devices a contract not to supply/consume power is sufficient; and

Establishing the port’s data role: optional, but if used must be performed before VDMs related to Alternate Modes are sent, or after DisplayPort Mode has been successfully exited. A DFP_U/UFP_U role swap, if performed, must be completed before entering the DisplayPort mode.

The result is to move to either the DFP_U or the UFP_U message flows, depending on the port role.

Note: Implementers should take care to ensure that sufficient time is allowed to discover the connected display during system boot and resume from sleep.

Figure 5-1 Connect Initial Actions

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Figure 5-2 shows the message flow at the DFP_U for DisplayPort Alternate Mode discovery and entry and the

receipt of Attention messages, the generation of status update requests, up to the point where the port is ready to be configured to use DisplayPort. While waiting to be configured to use DisplayPort, the port waits in a DisplayPort Mode/USB Configuration wait state. When the DFP_U and the UFP_U are attached via a USB Type-C to USB Type-C cable, the DFP_U shall ensure that the capabilities of the DFP_U, the cable (where present) and the UFP_U are compatible with each other (i.e. that the connection is not DFP_D-to-DFP_D or UFP_D-to-UFP_D, and that there is Proposed DisplayPort Alt Mode on USB Type-C DISTRIBUTION TO NON-MEMBERS IS PROHIBITED

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a signaling configuration that all three support). If the DFP_U, cable and UFP_U are incompatible, then the DFP_U shall stay in USB Mode.

Figure 5-2 DFP_U DisplayPort Alternate Mode Discovery and Entry

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Figure 5-3 shows the message flow at the DFP_U for configuration, up to the point that the SuperSpeed connections and SBU connections start to use DisplayPort. Note: If the UFP_U requests MF Mode, and if the DFP_U supports MF Mode, then it is a matter of DFP_U implementation policy whether to select MF Mode or stay in DP Mode.

Figure 5-3 DFP_U DisplayPort Configuration

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Figure 5-4 shows the message flow when the DFP_U is operating in a DisplayPort configuration and receives a request for reconfiguration by a DisplayPort Status transmitted as the VDO in an Attention Command from the UFP_U. The UFP_U may send a DisplayPort Status that either requests a different configuration, or requests a switch to using USB instead of DisplayPort. If the DisplayPort Status indicates that the UFP_U no longer has a connected display, then the DFP_U shall initiate a transition to the USB Configuration. In addition the DFP_U may make a policy change, for example in preparation to exiting DisplayPort Mode prior to using PD for a data role swap.

Figure 5-4 DFP_U DisplayPort Operation and Reconfiguration

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Figure 5-5 shows the sequence at the DFP_U for reconfiguring the port to USB operation. This may be performed as a result of a configuration request to reconfigure from DisplayPort configuration, or may be performed as a result of an Exit Mode request, which can only be completed when in USB Configuration. Prior to transmitting the

DisplayPort Configure Command specifying USB configuration, the DFP_U places the previously reconfigured pins into USB Safe Sate and isolates the SBU pins, as described in section 5.2.6.

Figure 5-5 DFP_U Reconfigure to USB Configuration

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Figure 5-6 shows the Exit Mode sequence at the DFP_U. This sequence is only entered when the port configuration has been set or reset to USB Configuration.

Figure 5-6 DFP_U Exit Mode

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Figure 5-7 shows the message flow for the UFP_U DisplayPort Alternate Mode discovery and entry up to the point where the port enters a wait state ready to be configured to use DisplayPort.

Note that the USB Type-C specification requires that the UFP_U present a USB Billboard Device Class if it fails to receive and act upon an Enter Mode request within tAMETimeout (see Section 5.1.3 of USB Type-C). In this case, the UFP_U shall await further Commands from the DFP_U (for example, it may receive a DisplayPort Enter Mode Command even though it has already presented USB Billboard).

Figure 5-7 UFP_U DisplayPort Alternate Mode Discovery and Entry

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Figure 5-8 shows the message flow for the UFP_U while in the USB Wait State. In this state, it may receive a

Command to report status, a Command to configure the UFP_U into a DisplayPort Configuration, or a Command to exit DisplayPort Mode. Also during this state it may detect a change in connection status on its DisplayPort side (such as a DFP_D or a UFP_D is attached) and consequently generate an Attention message towards the DFP_U.

Figure 5-8 UFP_U USB Configuration Wait State

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Figure 5-9 shows the message flow at the UFP_U for configuration, up to the point that the SuperSpeed connections and SBU connections start to use DisplayPort.

Figure 5-9 UFP_U DisplayPort Configuration

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Figure 5-10 shows the message flow for UFP_U operation while in the DisplayPort configuration. If it detects a

change in the connection status on its DisplayPort side (for example a DFP_D or UFP_D is disconnected) it sends an Attention message to the DFP_U. Simultaneously it waits for a Command from the DFP_U. The UFP_U may receive

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a status update Command, a configuration Command for a different configuration, or a Command to switch to using USB instead of DisplayPort.

Figure 5-10 UFP_U DisplayPort Operation

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Figure 5-11 shows the Exit Mode sequence at the UFP_U. The UFP_U shall acknowledge the Command but takes no further action. The UFP_U shall not send Attention messages after acknowledging the Exit Mode Command. The

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UFP_U shall not restart its tAMETimeout (USB Billboard connect) timer (i.e. USB Billboard is never displayed once the connection has entered DisplayPort Mode).

Figure 5-11 UFP_U Exit Mode

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A port may be disconnected or be subject to a Hard Reset at any time. The port resets the DisplayPort Alternate Mode. Figure 5-12 shows the sequence of actions on a Hard Reset or Disconnection at both the DFP_U and the UFP_U. The UFP_U shall reduce its power consumption to no more than the default VCONN. No Alternate Mode messaging takes place. After a Hard Reset, the port behaves as if a new connection has been detected.

Figure 5-12 Hard Reset and Disconnection

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6 Miscellaneous

6.1 VCONN and VBUS

As specified in USB Type-C, VCONN is provided by the DFP_U at a voltage between 2.7V and 5.5V. As DisplayPort adapters may require more power than that specified in USB Type-C, a DFP_U supporting DisplayPort on a USB Type-C receptacle shall support 1.5W at any voltage in this range when operating in DisplayPort Mode.

The adapter shall operate at any voltage between 2.7V and 5.5V (as presented at the adapter’s USB Type-C plug, there may be an IR drop on a VCONN wire in the adapter’s cable), and the adapter shall not consume in excess of 1.5W. PD communications may be maintained if the voltage falls below 2.7V, but the power consumption shall not exceed 70mW and DisplayPort adapter functionality may be disabled. The adapter shall report if it continues to operate but disables DisplayPort functionality (see Table 5-3).

During the Discovery Process and at any time that DisplayPort Mode is not entered, the adapter shall comply with the USB Type-C VCONN power consumption requirements.

A DFP_U supporting DisplayPort Mode may either be a USB Power Provider, or may be a UFP_U with Accessory Support that has detected a Powered Accessory (as defined in the USB Type-C specification), and in this respect is operating as a DFP_U but not providing VBUS. Correspondingly, no assumptions can be made about the presence or direction of power on VBUS.

An adapter supporting DisplayPort on a USB Type-C plug shall operate as a Powered Accessory. It is not required to provide power on VBUS, and does not depend on the presence of power on VBUS (except to power the presentation of USB Billboard class when required). A UFP_U with Accessory Support supporting DisplayPort on a USB Type-C receptacle shall not depend on power being available on VBUS. An Adapter shall power the USB Billboard class from VBUS not VCONN so that Billboard is presented should the Adapter be plugged into a DFP_U that does not support Alternate Modes and does not support VCONN.

6.2 Low power operation

PD remains operational during system low power modes. The DFP_U shall not exit the DisplayPort Mode (i.e. issue an Exit Mode Command) during display sleep (as controlled by writing to DisplayPort DPCD 00600h). It is recommended that a DFP_U does not exit the DisplayPort Mode during system low power states.

6.3 Equivalent USB Functionality

The USB Type-C specification strongly encourages devices that support Alternate Modes to provide equivalent USB functionality where such exists for best user experience (see section 5.1 of the USB Type-C specification). An

example of equivalent USB functionality for DisplayPort is the support of USB-AV for the uncompressed transport of video with a resolution of 1080p60 24bpp RGB.

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A DisplayPort Alternate Mode Examples

A.1.

Purpose

Examples are offered to illustrate how Alternate Modes, negotiated using USB-PD, are used to provide DisplayPort functionality beyond the basic functionality defined in USB Type-C. The examples are not intended to be complete designs.

A.1.1. DisplayPort Alternate Mode Examples

There are many usage scenarios for including DisplayPort on a USB Type-C connector. In all cases, the system with a USB Type-C connector may be a USB Host or a USB Device, and, independently, may act as a DFP_D or a UFP_D.

Some possible examples include:

   

Transmission of DisplayPort over a USB Type-C to USB Type-C cable;

Transmission of DisplayPort over a USB Type-C to Legacy DisplayPort plug or receptacle cable (either direction);

Transmission of DisplayPort over a USB Type-C to other video format connector cable (e.g. HDMI, VGA). In these cases, the adapter would also contain a DisplayPort to other video format protocol converter; Transmission of DisplayPort and USB 3.1 simultaneously to a dock (DisplayPort is limited to two lanes in this example as two of the USB SuperSpeed data signal pairs are used for USB Enhanced SuperSpeed signaling).

These particular examples are intended only to illustrate the overall Discovery Process and Alternate Mode entry and exit flow using PD vendor defined messages. Note that additional messaging is used to support the DisplayPort Alternate Mode specific configuration, status and control. A.2.

USB Type-C USB Host to DisplayPort Video Adapter Example

This example describes a USB Host with a USB Type-C receptacle that also can act as a DFP_D, and connects to an adapter that has a USB Type-C plug and a DisplayPort plug to adapt to a legacy DisplayPort monitor. Note that the same DisplayPort functionality can be supported by a USB Device. A.2.1. DisplayPort Video Adapter Assumptions



The DisplayPort Video Adapter is a cable with a USB Type-C plug on one end and a Legacy DisplayPort connector on the other. It is an active adapter that contains circuitry (e.g. in the plug overmold, lump in the cable etc.) that communicates with the USB Host to expose its capabilities and enable its functionality. The DisplayPort Video Adapter does not provide power to charge the USB Host because DisplayPort does not support the provision of power over the cable.

The Host in this example has the capability to source native DisplayPort video (i.e. act as a DisplayPort Source).

The Host and the DisplayPort Video Adapter both use the specific USB SID associated with DisplayPort (DP_SID) to identify themselves. DP_SID is used firstly to indicate support for DisplayPort as a Alternate Mode and secondly to distinguish Commands that are specific to the support of DisplayPort as a Alternate Mode.

The Host is permitted to use the DisplayPort Video Adapter only if it identifies it as a DisplayPort Video Adapter. Failure to meet this results in a connection to a USB Billboard Device that will provide error information.

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  



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

The DisplayPort Video Adapter is powered by VCONN for the switch, CC logic and PD engine and the DisplayPort functions, but the USB 2.0 related functions must be powered by VBUS.

A.2.2. Block Diagrams

Figure A-1 shows a block diagram of the Host system with its MUX and Figure A-2 shows a block diagram of the DisplayPort Video Adapter cable assembly.

Figure A-1 Host System Block Diagram

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The Host has a MUX that can steer either: 1) the USB SS signals, or 2) all four lanes of the DisplayPort signals, or 3) two lanes of the DisplayPort signals together with the USB SS signals to the USB Type-C receptacle. The MUX or a combination of the MUX and DisplayPort port output manages the USB Type-C plug flipping. When the USB-PD block is instructed by the Host system to reconfigure the pins on the port to output DisplayPort signaling, the MUX is activated when the attached system identifies itself as a DisplayPort Video Adapter cable in the Discovery Process and responds to the Enter Mode request with an ACK. If the DisplayPort Video Adapter responds at any point during the Discovery Process with a NAK, the Host shall stay in the default USB 2.0/USB 3.1 configuration. The Host sees that the operational mode has changed based on the OpMode signal.

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The DisplayPort Video Adapter cable assembly provides a USB-PD interface to communicate with the Host. It also, by default, provides a USB 2.0 Device interface that is used by Hosts that do not support DisplayPort video adapters to detect that a DP Video Adapter is connected and to provide information for the user about the adapter and the Host system’s inability to use it. The DisplayPort video adapter also contains circuitry to isolate the SBU

connections until DisplayPort Mode is established. The DisplayPort Video Adapter is powered by VCONN for the switch, CC logic and PD engine and the DisplayPort functions, but the USB 2.0 related functions must be powered by VBUS. The same Video Adapter can be plugged into a USB Host or a USB Device (with dual role discovery), i.e. either may act as a DisplayPort Source. In the latter case, VBUS is not available, so it is not used by the adapter. A.2.3. Solution

The Host system and the DisplayPort Video Adapter use USB-PD DisplayPort Defined Messages to communicate and take advantage of advanced features.

The flow of messages from the point after the DisplayPort Video Adapter is plugged into the USB Type-C receptacle, plug orientation has been determined and Host/Device relationship established, is as follows:



Host system does not support PD

o After tAMETimeout, the Host will see the USB 2.0 Device interface with USB Billboard and will

report to the user that an unsupported Device has been connected, identifying the type of Device from the USB descriptor information presented in the USB Billboard.

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 Host system supports PD and advanced functions, but does not support any DisplayPort Video Adapter(s)

o The Host may look for other advanced functions, but does support the DisplayPort Video Adapter

even though its presence is discovered, as the video adapter responds with DP_SID that the Host does not recognize as identifying something that it supports. o Since DP Video Adapters are not supported, after tAMETimeout the Host will see the USB 2.0

Device interface with USB Billboard and will report to the user that an unsupported Device has

been connected, identifying the type of Device from the USB descriptor information presented in the USB Billboard.

 Host system supports PD and the DisplayPort Video Adapter

o The Host looks for advanced functions and discovers a DisplayPort Video Adapter by means of

responses to USB-PD messages using DP_SID. o Since a usable DisplayPort Video Adapter is discovered, the Host enters DisplayPort Mode and then

reconfigures its USB Type-C receptacle to output DisplayPort signals on the connector. The video adapter cancels its tAMETimeout on entry to DisplayPort Mode.

This example uses the basic extensions when connected that do the following: Base Set VDMs used

   

Discover SVIDs

Discover Modes (DP_SID)

Enter Mode (DP_SID, Alternate Mode offset) Exit Mode (DP_SID, Alternate Mode offset)

Process Outline

The Host acts in its role as a DFP_U.

1. DFP_U detects presence of a device (CC pins) and connector orientation 2. DFP_U applies 5V to VBUS and VCONN

3. DFP_U uses PD to make a power contract with the UFP_U 4. DFP_U runs Discover SVID process

a. Sends Discover SVIDs message

b. Receives Response message with a list of SVIDs for which the UFP_U supports Modes

5. DFP_U runs Discover Modes process

a. Sends Discover Mode VDM for each of the SVIDs previously discovered that it supports, including

DP_SID b. Receives Response message with a list of Modes associated with DP_SID

c. If a DisplayPort Video Adapter is not discovered – stays in USB Mode, discovers the USB

Billboard after tAMETimeout, and informs user - done d. Else

6. DPF runs Enter Mode process

a. Sends Enter Mode VDM with DP_SID and offset to Mode

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b. Receives Response

i. Responder ACK – DFP_U is now attached to the DisplayPort Video Adapter, running in

DisplayPort Mode and USB Configuration ii. Responder NAK – DFP_U returns to default USB 3.1 configuration

7. DFP_U discovers adapter status, and waits until the adapter reports that it has a connected display 8. DFP_U runs the DisplayPort Configure process

a. Places signals to be reconfigured into Safe State b. Sends a DisplayPort Configure Command to the adapter c. Receives Responder ACK response d. Configures signals to use DisplayPort

9. If DFP_U receives a Status update from Device that requires a change in configuration, DFP_U re-runs the

Configure Process (possibly reconfiguring the interface back into USB Mode) 10. DFP_U continues to run Mode until

a. Explicitly exited by an Exit Mode VDM b. Hard Reset signaling on PD c. Power is removed from the host d. Adapter is disconnected

The Host and the DisplayPort Video Adapter will use the base set VDMs without change but augmented by the DP_SID-specific VDMs.

Note the DisplayPort Video Adapter is required to follow and/or not interfere with ALL rules for normal PD operation. A.3.

USB Dock with DisplayPort Example

In this example, a Device uses its USB Type-C connector as a cradle dock for a Host. Note: There are additional mechanical requirements that are not covered in this example. A.3.1. USB Dock with DisplayPort Assumptions

   

The cradle dock provides mechanical alignment and attachment in addition to those provided by the USB Type-C connector.

The dock uses USB-PD to charge/power the Host.

The dock sources two lanes of native DisplayPort video on a Legacy DisplayPort receptacle.

The dock contains a USB hub that exposes three USB ports and attached internal USB Devices: 1) a USB Ethernet Device (RJ-45 connector) and 2) a USB audio Device (a 3.5mm phone jack).

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A.3.2. Block Diagrams

Figure A-3 Example USB Dock with DisplayPort

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The dock communicates to the Host that it can act as a two lane DisplayPort Source and participates in the

negotiation process to put the Host in the Alternate mode that supports the dock. Since USB-PD is used, it may also be used to negotiate power for the dock and Host. In this example, the USB SS signals allow the dock to work as a USB hub with a host that does not support PD or DisplayPort.

A more complex dock can be designed that multiplexes SSTx1/SSRx1 to be either the USB SS channel or to support an additional two lanes of DisplayPort. Such a dock is outside the scope of this example, but is not precluded by this specification’s support for Alternate Modes. A.3.3. Solution

The Host system and USB Dock with DisplayPort use USB-PD Vendor Defined Messages to communicate and take advantage of advanced features.

The flow of messages from the point where the USB dock with DisplayPort is plugged into the USB Type-C receptacle, plug orientation has been determined and Host/Device relationship established is as follows:



Host system does not support PD

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 

o The Host will discover the USB hub and operate as it would when connected to a USB hub o After tAMETimeout, the Host will see the USB 2.0 Device interface with USB Billboard and will

report to the user that an unsupported Device has been connected, identifying the type of Device from the USB descriptor information presented in USB Billboard. Host system supports PD and advanced functions but does not support the USB Dock with DisplayPort

o The Host will discover the USB hub and operate as it would for a USB hub.

o The Host may look for other advanced functions, but does support the USB Dock with DisplayPort. o Since the USB Dock with DisplayPort is not supported, after tAMETimeout the Host will see the

USB 2.0 Device interface with USB Billboard and will report to the user that an unsupported Device has been connected, identifying the type of Device from the USB descriptor information presented in USB Billboard. Host system supports the USB Dock with DisplayPort

o The Host looks for advanced functions by discovering if the Device reports SVIDs for advanced

functions. It then discovers a USB Dock with DisplayPort by means of responses to USB-PD messages using DP_SID. o Since a usable USB Dock with DisplayPort is discovered, the Host enters DisplayPort Mode, signals

the dock to enter the ‘DisplayPort ‘ mode and then reconfigures the USB Type-C receptacle to output DisplayPort signals on SSTx2/SSRx2 on the connector. The USB Dock with DisplayPort cancels its tAMETimeout on entry to DisplayPort Mode. The Host sends USB SS signals on SSTx1/SSRx1 and operates USB through the hub in the Dock as normal.

This example uses the basic extensions when docked that do the following: Base Set VDMs used

   

Discover SVIDs

Discover Modes (DP_SID)

Enter Mode (DP_SID, Alternate Mode offset) Exit Mode (DP_SID, Alternate Mode offset)

Process Outline

The Host acts in its role as a DFP_U.

1. DFP_U detects presence of a device (CC pins) and connector orientation 2. DFP_U applies 5V to VBUS and VCONN

3. DFP_U discovers USB hub in the Dock with DisplayPort and enumerates the hub and the attached USB

Devices (if any) 4. DFP_U uses PD to make power contract with the Dock device 5. DFP_U runs Discover SVIDs process

a. Sends Discover SVIDs message

b. Receives Response message with list of SVIDs for which the Dock device has Modes

6. DFP_U runs Discover Modes process

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a. Sends Discover Modes VDM for each of the SVIDs previously discovered that it supports, including

DP_SID b. Receives Response message with a list of Modes associated with DP_SID

c. If a USB Dock with DisplayPort mode is not discovered – stays in USB Mode, discovers the USB

Billboard after tAMETimeout,and informs user– done d. Else

7. DFP_U runs Enter Mode process

a. Sends Enter Mode VDM with DP_SID and offset to Mode b. Receives Response –

i. Responder ACK - DFP_U is now attached to the USB Dock with DisplayPort, running in

DisplayPort Mode and USB Configuration ii. Responder NAK – DFP_U returns to the default USB 3.1 configuration

8. DFP_U discovers adapter status, and waits until the adapter reports that it has a connected display 9. DFP_U runs the DisplayPort Configure process

a. Places signals to be reconfigured into Safe State b. Sends a DisplayPort Configure Command to the adapter c. Receives Responder ACK response

d. Configures signals to use DisplayPort; Host is now supporting native DisplayPort signaling on the

dock’s Legacy DisplayPort connector in combination with USB SuperSpeed signaling

10. If DFP_U receives a Status update from Device that requires a change in configuration, Host re-runs the

Configure Process (possibly reconfiguring the interface back into USB Mode) 11. DFP_U stays in this mode until

a. The Host is removed from the dock

b. Explicitly exited by an Exit Alternate Mode VDM c. Hard Reset on PD

d. Power is removed from the host

The USB Dock with DisplayPort is required to follow and/or not interfere with ALL rules for normal PD operation.

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