DisplayPort

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DisplayPort
DisplayPort-rid.jpg
DisplayPort connector
Type Digital audio/video connector
Production history
Designer VESA
Designed May 2006
Produced 2008-present
Specifications
Hot pluggable Yes
External Yes
Electrical +3.3 V
Max. voltage 16.0 V
Max. current 500  mA
Audio signal Optional; 1-8 channels, 16 or 24-bit linear PCM; 32 to 192 kHz sampling rate; maximum bitrate 49152 Kbit/s
Video signal Optional, maximum resolution limited by available bandwidth
Data signal Yes
Bandwidth 1.62, 2.7, or 5.4 GHz symbol rate; 1, 2, or 4 lanes (total 5.184, 8.64, or 17.28  Gbit/s data rate) plus 1 Mbit/s or 720 Mbit/s for the auxiliary channel.
Protocol mini-packet
Cable Maximum length 15 meters for video transmission (resolution at least 1920×1080p60 at 24 bpp),
3 meters for full bandwidth transmission, made of materials of either copper or optical fibre.
Pins 20 pins for external connectors on desktops, notebooks, graphics cards, monitors, etc. and 30/20 pins for internal connections between graphics engines and built-in flat panels.
Pin out
DisplayPort Connector.svg

External connector (source-side) on PCB
Pin 1 ML_Lane 0 (p) Lane 0 (positive)
Pin 2 GND Ground
Pin 3 ML_Lane 0 (n) Lane 0 (negative)
Pin 4 ML_Lane 1 (p) Lane 1 (positive)
Pin 5 GND Ground
Pin 6 ML_Lane 1 (n) Lane 1 (negative)
Pin 7 ML_Lane 2 (p) Lane 2 (positive)
Pin 8 GND Ground
Pin 9 ML_Lane 2 (n) Lane 2 (negative)
Pin 10 ML_Lane 3 (p) Lane 3 (positive)
Pin 11 GND Ground
Pin 12 ML_Lane 3 (n) Lane 3 (negative)
Pin 13 CONFIG1 connected to Ground1)
Pin 14 CONFIG2 connected to Ground1)
Pin 15 AUX CH (p) Auxiliary Channel (positive)
Pin 16 GND Ground
Pin 17 AUX CH (n) Auxiliary Channel (negative)
Pin 18 Hot Plug Hot Plug Detect
Pin 19 Return Return for Power
Pin 20 DP_PWR Power for connector (3.3 V 500 mA)
1) Pins 13 and 14 may either be directly connected to ground or connected to ground through a pulldown device.

2) This is the pinout for source-side connector, the sink-side connector pinout will have lanes 0-3 reversed in order; i.e., lane 3 will be on pin 1 and 3 while lane 0 will be on pin 10 and 12.

DisplayPort is a digital display interface standard put forth by the Video Electronics Standards Association (VESA) since 2006. It defines a new royalty-free, digital audio/video interconnect, intended to be used primarily between a computer and its display monitor, or a computer and a home-theater system.

The first version was approved in May 2006, version 1.1a was approved on April 2, 2007, and the current version 1.2 was approved on December 22, 2009.

DisplayPort is designed to replace digital (DVI) and analog component video (VGA) connectors in the computer monitors and video cards, as well as replace internal digital LVDS links in computer monitor panels and TV panels. [1] HDMI connector with HDCP copy-protection is the de facto standard digital connection for high-definition consumer electronics devices and, recently, 1080p computer monitors, although it does not directly compete with DisplayPort. [2] [1] Unified Display Interface was a competing standard based on HDMI, [3] however the founding companies abandoned UDI in favor of DisplayPort.

Contents

[edit] Overview

The DisplayPort connector supports 1, 2, or 4 data pairs (lanes) in a Main Link, each with a symbol rate of 1.62, 2.7, or 5.4 GHz, with self-clock and optional audio signals. The video signal path supports 6 to 16 bits per color channel. The audio path supports up to 8 channels of 24 bit 192 KHz uncompressed PCM audio and can encapsulate compressed audio formats in the audio stream. [4] Computer support for DisplayPort audio was introduced by AMD in the Catalyst 9.12 hotfix.[5]

A bi-directional half-duplex auxiliary channel carries device management and device control data for the Main Link, such as VESA EDID, MCCS, and DPMS standards.

The data transmission protocol in DisplayPort is based on micro packets, allowing flexible allocation of available bandwidth, and is extensible for future feature additions. Unlike the separate DVI/HDMI and LVDS standards, DisplayPort supports both external (box-to-box) and internal (laptop LCD panel) display connections, and embeds the clock in the data signal.

Although DisplayPort's signal is not compatible with HDMI or DVI, Dual-mode ports (which are marked with DP++ logo) can use DisplayPort wires to transmit HDMI and single-link DVI signals which are then converted to higher signal levels by passive external adapters. Dual-link DVI and analog VGA are supported through powered adapters which perform active conversion.[4]

DisplayPort 1.1 supports a maximum of 8.64 Gbit/s data rate over a 2 meter cable. [6] It also supports alternative link layers such as fiber optic, allowing a much longer reach between source and display without signal degradation,[7], and supports HDCP in addition to DisplayPort Content Protection (DPCP).

DisplayPort version 1.2 was approved on December 22, 2009. Most significant improvement of the new version is the doubling of the bandwidth up to 17.28 Gbit/s, which allows for increased resolutions, higher refresh rates, and greater color depth. Other improvements include multiple independent video streams (daisy-chain connection with multiple monitors), support for stereoscopic 3D, increased AUX channel bandwidth (from 1 Mbit/s to 720 Mbit/s), Global Time Code (GTC) for sub 1 µs audio/video synchronisation, and addition of Apple Inc.'s Mini DisplayPort connector, which is much smaller and more appropriate for laptop computers and other small devices.[8][9][10][4]

[edit] Companion standards

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.[11] It supports 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 supports DisplayPort 1.2 data rates as well as 120 Hz sequential color monitors.

Direct Drive Monitor 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 supported resolutions and color depth are limited to 2-lane operation.

Internal DisplayPort (iDP) 1.0 was approved in April 2010. The iDP standard defines an internal link between a TV/monitor controller system on a chip and the display panel's timing controller, and aims to replace currently used internal LVDS lanes with DisplayPort connection.[12] iDP features 2.7 GHz clock (3.24 Gbit/s data rate) per lane, resulting in 6-fold decrease in wiring requirements over LVDS for the same resolution and refresh rate.[4]

PDMI (Portable Digital Media Interface) is an interconnection between docking stations/display devices and portable media players, which includes 2-lane DisplayPort v1.1a connection.[4] It has been ratified in February 2010 as ANSI/CEA-2017-A.

[edit] DRM protection

DisplayPort includes optional DPCP (DisplayPort Content Protection) copy-protection from Philips, which uses 128-bit AES encryption. It also features full authentication and session key establishment (each encryption session is independent). There is an independent revocation system. This portion of the standard is licensed separately. It also adds support for verifying 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.

Version 1.1 added support for HDCP.

[edit] Advantages over legacy standards

[edit] Compatibility with DVI and HDMI

Dual-mode DisplayPort
Dual-mode Pin Mapping
DisplayPort Pins DVI 1.0/HDMI Mode
Main Link Lane 0 TMDS Clock
Main Link Lane 1 TMDS Channel 0
Main Link Lane 2 TMDS Channel 1
Main Link Lane 3 TMDS Channel 2
AUX CH+ DDC Clock
AUX CH- DDC Data
DP_PWR DP_PWR
Hot Plug Detect Hot Plug Detect
Config 1 Cable Adaptor Detect
Config 2 CEC (HDMI only)

DisplayPort is capable of directly emitting single-link HDMI and DVI signals using Dual-mode DisplayPort. VESA has issued interoperability guidelines for supporting single-link DVI and HDMI through a DisplayPort connection using a relatively simple passive adapter that adjusts for the lower voltages required by DisplayPort. [2] [13] Dual-mode DisplayPort chipset detects the DVI or HDMI passive adapter and switches to DVI/HDMI mode which uses the 4-lane main DisplayPort link and AUX channel link to transmit 3 TMDS signals plus a Clock signal and Display Data Channel data/clock from the chipset. Dual-mode compatible ports are marked with the DP++ logo; most current DisplayPort graphics cards and monitors support this mode. [4]

A notable limitation is that Dual-mode can only transmit single-link DVI/HDMI, as the number of pins in the DisplayPort connector is insufficient for dual-link connections and an active converter is needed for Dual-Link DVI and analog VGA, however VESA foresees that all HDMI conversion will eventually be handled by active adapters which act as DisplayPort Sink devices, in order to facilitate easier updates to latest HDMI specs and support multiple streams, dual-link HDMI, [4], or DisplayPort connection with fewer than 4 lanes, as in PDMI. DVI 1.0 spec was finalized in 1999 and the DVI industry consortium has since disbanded, which means future updates to DVI spec are unlikely; also, although dual-link HDMI "Type B" is defined in the HDMI specs, it has not seen any practical use so far.

[edit] Technical specifications

†Sample data rates required by various display resolutions using common vertical blanking methods, Gbit/s
Resolution × color depth @ frame rate CVT CVT-R CEA-861-E
1280 × 720 × 24 bpp @ 60 Hz 1.79 1.54 1.78
1920 × 1080 × 24 bpp @ 60 Hz 4.15 3.33 3.56
1920 × 1200 × 30 bpp @ 60 Hz 5.81 4.62 -
2560 × 1600 × 30 bpp @ 60 Hz 10.46 8.06 -
3840 × 2160 × 30 bpp @ 60 Hz 21.39 16.00 -
Note: bpp is the number of bits for each pixel.

For RGB and YCbCr 4:4:4 encodings, bpp = 3 × bpc (bits per color component);
for YCbCr 4:2:2 subsampling, bpp = 2 × bpc.

[edit] Relationship with HDMI

The DisplayPort website states that DisplayPort is expected to complement HDMI, a popular compact audio/video interface.[2] DisplayPort can emit HDMI video and audio using passive adapters connected to Dual-mode ports, and supports HDCP content protection used in the HDMI standard.

Most of the DisplayPort supporters are computer companies such as Apple, Dell, HP, Lenovo, Fujitsu, Toshiba and Acer, some of which have released several computer monitors that support DisplayPort and some also with HDMI.[15][16]

HDMI has certain features that DisplayPort lacks such as native support for the xvYCC color space and Consumer Electronics Control (CEC) signals.[17][18] However, VESA asserts that CEC can be transmitted over the AUX channel if needed; [4] additional color spaces defined in Vendor Specific Block could also be defined using CEA EDID extensions, which were designed for DVI-mode connections which lack VSB communications.

DisplayPort is currently royalty free, while the HDMI royalty is 4 cents per device and has an annual fee of $10,000 for high volume manufacturers.[19] HDMI Licensing LLC claims that, like HDMI, the DisplayPort specification allows for compensation from implementers to unspecified rights holders.[20]

[edit] Products

 This section may require cleanup to meet Wikipedia's quality standards. Please improve this section if you can. (June 2010)

Before being acquired by AMD, one of the supporters, ATI reported that they were expecting DisplayPort products in early 2007. On July 25 2007, at AMD's Technology Analyst Day 2007, AMD renewed their commitment to supporting DisplayPort with the 790G chipset and RV670 graphics cards with external DisplayPort transmitter. The company also committed to implement the transmitter on chip level for its RV635 and RV620 graphics products in its Financial Analyst Day 2007 held on 13 December 2007, providing support without external transmitters. These products obtained certification from VESA on 19 March 2008.[21]

In 2009, some graphic card manufacturers started including DisplayPort on their graphic cards based on ATI/AMD RV870 Graphic chip.

The newest line of AMD/ATI graphics cards, the Radeon 5700 and 5800 series, are the first line to incorporate DisplayPort connector on a GPU-wide level, along side 2x DualLink DVI connectors, and a single HDMI connector. It will allow up to 3 displays on a single graphics card. A second version is also available with 6 Mini DisplayPorts allowing up to 6 displays on the same card.[22]

Genesis Microchip also announced DisplayPort products to be available in 2007,[23] as did Samsung.[24] A concept monitor by Dell implementing DisplayPort was demonstrated early May 2007.[25]

The Dell 3008WFP 30-inch (76 cm), released in January 2008 was the first monitor to support DisplayPort.[26][27] The Dell 2408WFP 24-inch (61 cm) followed in April 2008.[28] Apple's LED Cinema Display, and HP's LP2275w, LP2475w, and LP2480zx monitors also support DisplayPort. Dell also supplies current products such as the Adamo, Studio XPS, Latitude and Precision laptops and Optiplex desktops with DisplayPort connectors - sometimes superseding DVI connectors.

On 14 October 2008, Apple introduced several products featuring a Mini DisplayPort[29] as their sole video connector. As of 20 October 2009, all current Mac models available directly from Apple support output through a Mini DisplayPort. The current iMac, MacBook, MacBook Air, MacBook Pro, and Xserve models use Mini DisplayPort as their sole video output port while the Mac Mini and Mac Pro models have both a Mini DisplayPort and either a DVI port (Mac Pro) or an HDMI port (Mac Mini). The 27-inch iMac model also allows the Mini DisplayPort to act as an input, turning the iMac into a standalone display.[30]


Laptops supporting DisplayPort (chronologically):

[edit] Adopters and supporters

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

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

[edit] See also

[edit] References

  1. ^ a b Direct2Dell Blog: The Truth About DisplayPort vs. HDMI
  2. ^ a b c "DisplayPort FAQ". DisplayPort website. http://www.displayport.org/consumer/?q=content/faq. Retrieved 2008-06-19. 
  3. ^ Tuan Nguyen (2007-02-19). "The Future of HDMI". DailyTech. http://www.dailytech.com/The+Future+of+HDMI/article6098.htm. Retrieved 2007-07-16. 
  4. ^ a b c d e f g h i "DisplayPort Technical Overview, May 2010". VESA. 2010-05-23. http://www.displayport.org/cms/sites/default/files/downloads/DisplayPort_Technical_Overview.pdf. 
  5. ^ . AMD. http://support.amd.com/us/kbarticles/Pages/ATICatalyst912Hotfix.aspx. Retrieved 2009-12-18. 
  6. ^ Thomas Ricker (2007-01-03). "DisplayPort to support HDCP, too". Engadget. http://www.engadget.com/2007/01/03/displayport-to-support-hdcp-too/. Retrieved 2007-12-22. 
  7. ^ "Video Electronics Standards Association (VESA) Endorses Alternative to Copper Cables". Luxtera Inc.. 2007-04-17. http://www.luxtera.com/2007041644/video-electronics-standards-association-vesa-endorses-alternative-to-copper-cables-%E2%80%93-enables-optical-video-interconnect-in-displayport-standard.html. Retrieved 2010-01-19. 
  8. ^ Tony Smith, "DisplayPort revision to get mini connector, stereo 3D", The Register, 13 January 2009
  9. ^ "WinHEC 2008 GRA-583: Display Technologies". Microsoft. 2008-11-06. http://download.microsoft.com/download/5/E/6/5E66B27B-988B-4F50-AF3A-C2FF1E62180F/GRA-T583_WH08.pptx. 
  10. ^ "CES 2009 Press Event". VESA. 2009-01-11. http://www.displayport.org/news-presentations/press-releases/DP_CES_v3_09.pdf. 
  11. ^ "Embedded DisplayPort Standard Ready from VESA". VESA. 2009-02-23. http://www.displayport.org/news-presentations/press-releases/eDPpr.pdf. 
  12. ^ "VESA Issues Internal DisplayPort® Standard for Flat Panel TVs". VESA. 2010-05-10. http://www.displayport.org/cms/sites/default/files/downloads/press-releases/iDP_VESA_PR.pdf. 
  13. ^ "DisplayPort Interoperability Guideline Version 1.1a". VESA.org. 2009-02-05. http://www.displayport.org. Retrieved 2010-07-02. 
  14. ^ DisplayPort/DVI/HDMI Comparison table, VESA DisplayPort Standard v1.0—Audioholics Home Theater Reviews and News.
  15. ^ Paul Miller (2007-12-18). "Dell's 3008WFP 30-inch (760 mm)-inch LCD with DisplayPort sneaks available -- in US too". engadget. http://www.engadget.com/2007/12/18/dells-3008wfp-30-inch-lcd-with-displayport-sneaks-available/. Retrieved 2008-06-18. 
  16. ^ Thomas Ricker (2008-01-17). "Dell's 24-inch (610 mm)-inch 2408WFP monitor with DisplayPort (and everything else) now available". engadget. http://www.engadget.com/2008/01/17/dells-24-inch-2408wfp-monitor-with-displayport-and-everything/. Retrieved 2008-06-18. 
  17. ^ "HDMI Specification 1.3a". HDMI Licensing, LLC.. 2006-11-10. http://www.hdmi.org. Retrieved 2008-06-21. 
  18. ^ "DisplayPort 1.1a Standard". VESA.org. 2008-01-11. http://www.displayport.org. Retrieved 2008-06-23. 
  19. ^ "HDMI Adopter Terms". HDMI.org. http://www.hdmi.org/manufacturer/terms.aspx. Retrieved 2008-06-23. 
  20. ^ "Interview with Steve Venuti from HDMI Licensing". http://www.hdmi.org/pdf/2009_10_Veritas_Visus_Venuti_Interview.pdf. 
  21. ^ AMD Press Release: AMD Receives First Ever DisplayPort Certification for PC Graphics. Retrieved 2008-03-20.
  22. ^ "ATI Radeon HD 5870 1GB Graphics Card and AMD Eyefinity Review". PC Perspective. 2009-09-23. http://www.pcper.com/article.php?aid=783&type=expert&pid=4. Retrieved 2009-09-23. 
  23. ^ "Genesis Microchip (GNSS) Q4 2006 Earnings Conference Call". Seeking Alpha. 2006-05-02. http://seekingalpha.com/article/9956. Retrieved 2007-07-16. 
  24. ^ "Samsung touts development of first DisplayPort desktop LCD". TG Daily. 2006-07-25. http://www.tgdaily.com/content/view/33064/135/. Retrieved 2007-07-25. 
  25. ^ "Dell Shows Off Super-Slim Display Port LCD Monitor". Gearlog.com. 2007-05-17. http://www.gearlog.com/2007/05/dell_shows_off_superslim_displ.php. Retrieved 2007-07-16. 
  26. ^ Dell 3008WFP specifications. Retrieved 2008-01-30.
  27. ^ "Dell UltraSharp 3008WFP 30-Inch LCD Monitor". http://www.washingtonpost.com/wp-dyn/content/article/2008/01/03/AR2008010301753_pf.html. Retrieved 2008-06-25. 
  28. ^ "Dell UltraSharp 2408WFP". http://cnet.nytimes.com/lcd-monitors/dell-ultrasharp-2408wfp/4505-3174_7-32886455.html. Retrieved 2008-06-25. 
  29. ^ "Software Licensing and Trademark Agreement: Mini DisplayPort". http://developer.apple.com/softwarelicensing/agreements/minidisplayport.html. 
  30. ^ "Apple - iMac - Technical Specifications". http://www.apple.com/imac/specs.html. 
  31. ^ Analogix announces DisplayPort transmitter, published 2006-08-26, seen 2009-08-10
  32. ^ ASRock announces motherboard with embedded DisplayPort, published 2008-03-25, seen 2009-08-10
  33. ^ MSI announces video adaptor with DisplayPort, published 2008-01-17, seen 2009-08-10

[edit] External links

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