Exhibition

DisplayPort From Wikipedia - Features

Features[edit]

 DisplayPort Version
1.01.1–1.1a1.2–1.2a1.31.42.0
Hot-PluggableYesYesYesYesYesYes
Inline AudioYesYesYesYesYesYes
DisplayPort Content
Protection (DPCP)
DPCP 1.0[36](§1.2.6)DPCP 1.0DPCP 1.0DPCP 1.0DPCP 1.0DPCP 1.0
High-Bandwidth Digital
Content Protection (HDCP)
NoHDCP 1.3[9](§1.2.6)HDCP 1.3[37](§1.2.6)HDCP 2.2[20]HDCP 2.2HDCP 2.2
Dual-Mode (DP++)NoYesYesYesYesYes
Maximum DP++ Bandwidth
(TMDS Clock)
N/A4.95 Gbit/s
(165 MHz)
9.00 Gbit/s
(300 MHz)
18.00 Gbit/s
(600 MHz)
18.00 Gbit/s
(600 MHz)
18.00 Gbit/s
(600 MHz)
Stereoscopic 3D VideoNoYesYesYesYesYes
Multi-Stream Transport (MST)NoNoYesYesYesYes
High Dynamic Range Video (HDR)NoNoNoNoYesYes
Display Stream Compression (DSC)NoNoNoNoDSC 1.2DSC 1.2a
Panel ReplayNoNoNoNoNoYes[40]

DisplayPort Dual-Mode (DP++)[edit]

Dual-mode DisplayPort logo
Dual-mode pin mapping
DisplayPort pinsDVI/HDMI mode
Main Link Lane 0TMDS Channel 2
Main Link Lane 1TMDS Channel 1
Main Link Lane 2TMDS Channel 0
Main Link Lane 3TMDS Clock
AUX CH+DDC Clock
AUX CH−DDC Data
DP_PWRDP_PWR
Hot Plug DetectHot Plug Detect
Config 1Cable Adaptor Detect
Config 2CEC (HDMI only)

DisplayPort Dual-Mode (DP++), also called Dual-Mode DisplayPort, is a standard which allows DisplayPort sources to use simple passive adapters to connect to HDMI or DVI displays. Dual-mode is an optional feature, so not all DisplayPort sources necessarily support DVI/HDMI passive adapters, though in practice nearly all devices do. Officially, the "DP++" logo should be used to indicate a DP port that supports dual-mode, but most modern devices do not use the logo.

Devices which implement dual-mode will detect that a DVI or HDMI adapter is attached, and send DVI/HDMI TMDS signals instead of DisplayPort signals. The original DisplayPort Dual-Mode standard (version 1.0), used in DisplayPort 1.1 devices, only supported TMDS clock speeds of up to 165 MHz (4.95 Gbit/s bandwidth). This is equivalent to HDMI 1.2, and is sufficient for up to 1920 × 1080 or 1920 × 1200 at 60 Hz.

In 2013, VESA released the Dual-Mode 1.1 standard, which added support for up to a 300 MHz TMDS clock (9.00 Gbit/s bandwidth), and is used in newer DisplayPort 1.2 devices. This is slightly less than the 340 MHz maximum of HDMI 1.4, and is sufficient for up to 1920 × 1080 at 120 Hz, 2560 × 1440 at 60 Hz, or 3840 × 2160 at 30 Hz. Older adapters, which were only capable of the 165 MHz speed, were retroactively termed "Type 1" adapters, with the new 300 MHz adapters being called "Type 2".[50]

With the release of the DisplayPort 1.3 standard, VESA added dual-mode support for up to a 600 MHz TMDS clock (18.00 Gbit/s bandwidth), the full bandwidth of HDMI 2.0. This is sufficient for 1920 × 1080 at 240 Hz, 2560 × 1440 at 144 Hz, or 3840 × 2160 at 60 Hz. However, no passive adapters capable of the 600 MHz dual-mode speed have been produced as of 2018.

Dual-Mode limitations[edit]

Picture of a DisplayPort to DVI adapter after removing its enclosure. The chip on the board converts the voltage levels generated by the dual-mode DisplayPort device to be compatible with a DVI monitor.

Multi-Stream Transport (MST) [edit]

Multi-Stream Transport is a feature first introduced in the DisplayPort 1.2 standard. It allows multiple independent displays to be driven from a single DP port on the source devices by multiplexing several video streams into a single stream and sending it to a branch device, which demultiplexes the signal into the original streams. Branch devices are commonly found in the form of an MST hub, which plugs into a single DP input port and provides multiple outputs, but it can also be implemented on a display internally to provide a DP output port for daisy-chaining, effectively embedding a 2-port MST hub inside the display.[37](Fig. 2-59)[51]. Theoretically, up to 63 displays can be supported,[37](p20) but the combined data rate requirements of all the displays cannot exceed the limits of a single DP port (17.28 Gbit/s for a DP 1.2 port, or 25.92 Gbit/s for a DP 1.3/1.4 port). In addition, the maximum number of links between the source and any device (i.e. the maximum length of a daisy-chain) is 7,[37](§2.5.2), and the maximum number of physical output ports on each branch device (such as a hub) is 7.[37](§2.5.1) With the release of MST, standard single-display operation has been retroactively named "SST" mode (Single-Stream Transport).

Daisy-chaining is a feature that must be specifically supported by each intermediary display; not all DisplayPort 1.2 devices support it. Daisy-chaining requires a dedicated DisplayPort output port on the display. Standard DisplayPort input ports found on most displays cannot be used as a daisy-chain output. Only the last display in the daisy-chain does not need to support the feature specifically or have a DP output port. DisplayPort 1.1 displays can also be connected to MST hubs, and can be part of a DisplayPort daisy-chain if it is the last display in the chain.[37](§2.5.1)

The host system's software also needs to support MST for hubs or daisy-chains to work. While Microsoft Windows environments have full support for it, Apple operating systems currently do not support MST hubs or DisplayPort daisy-chaining as of macOS 10.13 ("High Sierra").[52][53]

DisplayPort-to-DVI and DisplayPort-to-HDMI adapters/cables may or may not function from an MST output port; support for this depends on the specific device.[citation needed]

MST is supported by USB Type-C DisplayPort Alternate Mode, so standard DisplayPort daisy-chains and MST hubs do function from Type-C sources with a simple Type-C to DisplayPort adapter.[54]

High Dynamic Range (HDR)[edit]

Support for HDR video was introduced in DisplayPort 1.4. It implements the CTA 861.3 standard for transport of static HDR metadata in EDID.[23]

Content protection [edit]

DisplayPort 1.0 includes optional DPCP (DisplayPort Content Protection) from Philips, which uses 128-bit AES encryption. It also features full authentication and session key establishment. Each encryption session is independent, and it has an independent revocation system. This portion of the standard is licensed separately. It also adds the ability to verify the proximity of the receiver and transmitter, a technique intended to ensure users are not bypassing the content protection system to send data out to distant, unauthorized users.[9](§6)

DisplayPort 1.1 added optional implementation of industry-standard 56-bit HDCP (High-bandwidth Digital Content Protection) revision 1.3, which requires separate licensing from the Digital Content Protection LLC.[9](§1.2.6)

DisplayPort 1.3 added support for HDCP 2.2, which is also used by HDMI 2.0.[20]

Cost[edit]

VESA, the creators of the DisplayPort standard, state that the standard is royalty-free to implement. However, in March 2015, MPEG LA issued a press release stating that a royalty rate of $0.20 per unit applies to DisplayPort products manufactured or sold in countries that are covered by one or more of the patents in the MPEG LA license pool, which includes patents from Hitachi MaxellPhilipsLattice SemiconductorRambus, and Sony.[55][56] In response, VESA updated their DisplayPort FAQ page with the following statement:[57]

MPEG LA is making claims that DisplayPort implementation requires a license and a royalty payment. It is important to note that these are only CLAIMS. Whether these CLAIMS are relevant will likely be decided in a US court.

As of October 2017 there still seems to be no royalty, according to the VESA's official FAQ.

While the standard may not require any per-device royalty fees, VESA requires membership for access to said standards.[58] The minimum cost is presently $5,000.[59]

Advantages over DVI, VGA and FPD-Link[edit]

In December 2010, several computer vendors and display makers including Intel, AMD, Dell, Lenovo, Samsung and LG announced they would begin phasing out FPD-Link, VGA, and DVI-I over the next few years, replacing them with DisplayPort and HDMI.[60][61] One notable exception to the list of manufacturers is Nvidia, who has yet[when?] to announce any plans regarding future implementation of legacy interfaces.[citation needed]

DisplayPort has several advantages over VGA, DVI, and FPD-Link.[62]

Comparison with HDMI[edit]

Although DisplayPort has much of the same functionality as HDMI, it is a complementary connection used in different scenarios.[66][67] A dual-mode DisplayPort port can emit an HDMI signal via a passive adapter.

Market share[edit]

Figures from IDC show that 5.1% of commercial desktops and 2.1% of commercial notebooks released in 2009 featured DisplayPort.[60] The main factor behind this was the phase-out of VGA, and that both Intel and AMD planned to stop building products with FPD-Link by 2013. Nearly 70% of LCD monitors sold in August 2014 in the US, UK, Germany, Japan, and China were equipped with HDMI/DisplayPort technology, up 7.5% on the year, according to Digitimes Research.[76] IHS Markit, an analytics firm, forecast that DisplayPort would surpass HDMI in 2019.[77]

Companion standards[edit]

Mini DisplayPort[edit]

Mini DisplayPort (mDP) is a standard announced by Apple in the fourth quarter of 2008. Shortly after announcing Mini DisplayPort, Apple announced that it would license the connector technology with no fee. The following year, in early 2009, VESA announced that Mini DisplayPort would be included in the upcoming DisplayPort 1.2 specification. On 24 February 2011, Apple and Intel announced Thunderbolt, a successor to Mini DisplayPort which adds support for PCI Express data connections while maintaining backwards compatibility with Mini DisplayPort based peripherals.[78]

Micro DisplayPort[edit]

Micro DisplayPort would have targeted systems that need ultra-compact connectors, such as phones, tablets and ultra-portable notebook computers. This standard would have been physically smaller than the currently available Mini DisplayPort connectors. The standard was expected to be released by Q2 2014.[79] This project seems aborted to be replaced by DisplayPort Alt Mode for USB Type-C Standard.[80]

DDM[edit]

Direct Drive Monitor (DDM) 1.0 standard was approved in December 2008. It allows for controller-less monitors where the display panel is directly driven by the DisplayPort signal, although the available resolutions and color depth are limited to two-lane operation.

Display Stream Compression[edit]

Display Stream Compression (DSC) is a VESA-developed low-latency compression algorithm to overcome the limitations posed by sending high-resolution video over physical media of limited bandwidth. It is a visually lossless low-latency algorithm based on delta PCMcoding and YCoCg-R color space; it allows increased resolutions and color depths and reduced power consumption.[81][82]

DSC has been tested to meet the requirements of ISO/IEC 29170-2 Evaluation procedure for nearly lossless coding using various test patterns, noise, subpixel-rendered text (ClearType), UI captures, and photo and video images.[82]

DSC version 1.0 was released on 10 March 2014, but was soon deprecated by DSC version 1.1 released on 1 August 2014. The DSC standard supports up to 3:1 compression ratio with constant or variable bit rate, 4:4:4 chroma subsampling, optional 4:2:2 conversion and 6/8/10/12 bits per color component.

DSC version 1.2 was released on 27 January 2016 and is included with DisplayPort 1.4; version 1.2a was released on 18 January 2017. The update includes native encoding of 4:2:2 and 4:2:0 formats in pixel containers, 14/16 bits per color, and minor modifications to the encoding algorithm.

DSC compression works on a horizontal line of pixels encoded using groups of three consecutive pixels for native 4:4:4 and simple 4:2:2 formats, or six pixels (three compressed containers) for native 4:2:2 and 4:2:0 formats. If RGB encoding is used, it is first converted to reversible YCgCo. Simple conversion from 4:2:2 to 4:4:4 can add missing chroma samples by interpolating neighboring pixels. Each luma component is coded separately using three independent substreams (four substreams in native 4:2:2 mode). Prediction step is performed using one of the three modes: modified median adaptive coding (MMAP) algorithm similar to the one used by JPEG-LS, block prediction (optional for decoders due to high computational complexity, negotiated at DSC handshake), and midpoint prediction. Bit rate control algorithm tracks color flatness and buffer fullness to adjust the quantization bit depth for a pixel group in a way that minimizes compression artifacts while staying within the bitrate limits. Repeating recent pixels can be stored in 32-entry Indexed Color History (ICH) buffer, which can be referenced directly by each group in a slice; this improves compression quality of computer-generated images. Alternatively, prediction residuals are computed and encoded with entropy coding algorithm based on delta size unit-variable length coding (DSU-VLC). Encoded pixel groups are then combined into slices of various height and width; common combinations include 100% or 25% picture width, and 8-, 32-, or 108-line height.

On 4 January 2017, HDMI 2.1 was announced which supports up to 10K resolution and uses DSC 1.2 for video that is higher than 8K resolution with 4:2:0 chroma subsampling.[83][84][85]

eDP[edit]

Embedded DisplayPort (eDP) 1.0 standard was adopted in December 2008. It aims to define a standardized display panel interface for internal connections; e.g., graphics cards to notebook display panels.[86] It has advanced power-saving features including seamless refresh rate switching. Version 1.1 was approved in October 2009 followed by version 1.1a in November 2009. Version 1.2 was approved in May 2010 and includes DisplayPort 1.2 data rates, 120 Hz sequential color monitors, and a new display panel control protocol that works through the AUX channel.[13] Version 1.3 was published in February 2011; it includes a new Panel Self-Refresh (PSR) feature developed to save system power and further extend battery life in portable PC systems.[87] PSR mode allows GPU to enter power saving state in between frame updates by including framebuffer memory in the display panel controller.[13] Version 1.4 was released in February 2013; it reduces power consumption with partial-frame updates in PSR mode, regional backlight control, lower interface voltage, and additional link rates; the auxiliary channel supports multi-touch panel data to accommodate different form factors.[88] Version 1.4a was published in February 2015; it is based on DisplayPort 1.3 and supports HBR3 data rate, Display Stream Compression 1.1, Segmented Panel Displays, and partial updates for Panel Self-Refresh.[89] Version 1.4b was published in October 2015; its protocol refinements and clarifications are intended to enable adoption of eDP 1.4 in production by mid-2016.[90]

iDP[edit]

Internal DisplayPort (iDP) 1.0 was approved in April 2010. The iDP standard defines an internal link between a digital TV system on a chip controller and the display panel's timing controller. It aims to replace currently used internal FPD-Link lanes with DisplayPort connection.[91] iDP features unique physical interface and protocols, which are not directly compatible with DisplayPort and are not applicable to external connection, however they enable very high resolution and refresh rates while providing simplicity and extensibility.[13]iDP features non-variable 2.7 GHz clock and is nominally rated at 3.24 Gbit/s data rate per lane, with up to sixteen lanes in a bank, resulting in six-fold decrease in wiring requirements over FPD-Link for a 1080p24 signal; other data rates are also possible. iDP was built with simplicity in mind and it doesn't have AUX channel, content protection, or multiple streams; however it does have frame sequential and line interleaved stereo 3D.[13]

PDMI[edit]

Portable Digital Media Interface (PDMI) is an interconnection between docking stations/display devices and portable media players, which includes 2-lane DisplayPort v1.1a connection. It has been ratified in February 2010 as ANSI/CEA-2017-A.

wDP[edit]

Wireless DisplayPort (wDP) enables DisplayPort 1.2 bandwidth and feature set for cable-free applications operating in 60 GHz radio band; it was announced on November 2010 by WiGig Alliance and VESA as a cooperative effort.[92]

SlimPort[edit]

A SlimPort-to-HDMI adapter, made by Analogix

SlimPort, a brand of Analogix products,[93] complies with Mobility DisplayPort, also known as MyDP, which is an industry standard for a mobile audio/video Interface, providing connectivity from mobile devices to external displays and HDTVs. SlimPort implements the transmission of video up to 4K-UltraHD and up to eight channels of audio over the micro-USB connector to an external converter accessory or display device. SlimPort products support seamless connectivity to DisplayPort, HDMI and VGA displays.[94] The MyDP standard was released in June 2012,[95] and the first product to use SlimPort was Google's Nexus 4 smartphone.[96]

SlimPort is an alternative to Mobile High-Definition Link (MHL).[97][98]

DisplayID[edit]

DisplayID is designed to replace the E-EDID standard. DisplayID features variable-length structures which encompass all existing EDID extensions as well as new extensions for 3D displays and embedded displays.

The latest version 1.3 (announced on 23 September 2013) adds enhanced support for tiled display topologies; it allows better identification of multiple video streams, and reports bezel size and locations.[99] As of December 2013, many current 4K displays use a tiled topology, but lack a standard way to report to the video source which tile is left and which is right. These early 4K displays, for manufacturing reasons, typically use two 1920×2160 panels laminated together and are currently generally treated as multiple-monitor setups.[100] DisplayID 1.3 also allows 8K display discovery, and has applications in stereo 3D, where multiple video streams are used.

DockPort[edit]

DockPort, formerly known as Lightning Bolt, is an extension to DisplayPort to include USB 3.0 data as well as power for charging portable devices from attached external displays. Originally developed by AMD and Texas Instruments, it has been announced as a VESA specification in 2014.[101]

USB-C[edit]

On 22 September 2014, VESA published the DisplayPort Alternate Mode on USB Type-C Connector Standard, a specification on how to send DisplayPort signals over the newly released USB-C connector. One, two or all four of the differential pairs that USB uses for the SuperSpeed bus can be configured dynamically to be used for DisplayPort lanes. In the first two cases, the connector still can carry a full SuperSpeed signal; in the latter case, at least a non-SuperSpeed signal is available. The DisplayPort AUX channel is also supported over the two sideband signals over the same connection; furthermore, USB Power Delivery according to the newly expanded USB-PD 2.0 specification is possible at the same time. This makes the Type-C connector a strict superset of the use-cases envisioned for DockPort, SlimPort, Mini and Micro DisplayPort.[102]

Products[edit]

Dual-mode DisplayPort connector

Since its introduction in 2006, DisplayPort has gained popularity within the computer industry and is featured on many graphic cards, displays, and notebook computers. Dell was the first company to introduce a consumer product with a DisplayPort connector, the Dell UltraSharp 3008WFP, which was released in January 2008.[103] Soon after, AMD and Nvidia released products to support the technology. AMD included support in the Radeon HD 3000 series of graphics cards, while Nvidia first introduced support in the GeForce 9 series starting with the GeForce 9600 GT.[104][105]

A Mini DisplayPort connector

Later the same year, Apple introduced several products featuring a Mini DisplayPort.[106] The new connector – proprietary at the time – eventually became part of the DisplayPort standard, however Apple reserves the right to void the license should the licensee "commence an action for patent infringement against Apple".[107] In 2009, AMD followed suit with their Radeon HD 5000 Series of graphics cards, which featured the Mini DisplayPort on the Eyefinity versions in the series.[108]

Nvidia launched NVS 810 with 8 Mini DisplayPort outputs on a single card on 4 November 2015.[109]

Nvidia revealed the GeForce GTX 1080, the world's first graphics card with DisplayPort 1.4 support on 6 May 2016.[110] AMD followed with the Radeon RX 480 to support Displayport 1.3/1.4 on 29 June 2016.[111] The Radeon RX 400 Series will support DisplayPort 1.3 HBR and HDR10, dropping the DVI connector(s) in the reference board design.

In February 2017, VESA and Qualcomm announced that DisplayPort Alt Mode video transport will be integrated into the Snapdragon 835 mobile chipset, which powers smartphones, VR/AR head-mounted displays, IP cameras, tablets and mobile PCs.[112]

Support for DisplayPort Alternate Mode over USB-C[edit]

Patent holders[edit]

The following organizations hold active patents that contributed towards the development of DisplayPort technology, as listed in a patent pool by MPEG LA.[1]

OrganizationActive patents
Maxell24
Sun Patent Trust13
Lattice Semiconductor12
Philips10
Sony Corporation5
Rambus1

Participating companies[edit]

The following companies have participated in preparing the drafts of DisplayPort, eDP, iDP, DDM or DSC standards:

The following companies have additionally announced their intention to implement DisplayPort, eDP or iDP:

See also[edit]