DisplayPort

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DisplayPort


DisplayPort connector

Type Digital audio/video connector
Production history
Designer VESA
Designed May 2006
Produced 2008
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; 48, 96, or 192 kHz sampling rate; uncompressed; max. 6.144 Mbit/s bit rate
Video signal Optional, maximum resolution limited by available bandwidth
Data signal Yes
Bandwidth 1.62 or 2.7 GHz symbol rate; 1, 2, or 4 lanes (total 5.184 or 8.64 Gbit/s data rate) plus 1 Mbit/s for the auxiliary channel.
Protocol mini-packet
Cable Maximum length 15 metres for video transmission (resolution at least 1920×1080p60 at 24 bpp),
3 metres 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

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
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, while the current version (1.1a) was approved on January 11, 2008.

Contents

[edit] Overview

The DisplayPort connector supports 1, 2, or 4 data pairs in a Main Link that also carries clock and optional audio signals, each with a symbol rate of 1.62 or 2.7 Gbit/s. The video signal path supports 6 to 16 bits per color channel. A bi-directional auxiliary channel (at a constant 1 Mbit/s) carries management and device control data for the Main Link using VESA EDID and VESA MCCS standards. The video signal is not compatible with DVI or HDMI, but a DisplayPort connector can pass these signals through. While DVI and HDMI require separate clock signals, DisplayPort embeds the clock in the data signal. The data transmission protocol in DisplayPort is based on micro packets and is extensible for future feature additions, whereas DVI/HDMI transmission protocol is a Serial Data Stream at a multiple of 10 of the pixel clock rate. Finally, unlike the separate DVI/HDMI and LVDS standards, DisplayPort supports both external (box-to-box) and internal (laptop LCD panel) display connections.

DisplayPort currently supports a maximum of 8.64 Gbit/s data rate over a 2 metre cable.[1]

DisplayPort is a competitor to the HDMI connector (with HDCP copy-protection), the de facto digital connection for high-definition consumer electronics devices. Another competitor was Unified Display Interface,[2] a low cost compatible alternative to HDMI and DVI. However, the main supporter of UDI, Intel Corporation, has stopped the development of the technology and now supports DisplayPort.

Newly featured in version 1.1 is support for fiber optic cables as an alternative to copper, allowing a much longer reach between source and display without image degradation,[3] as well as DPCP (see below).

Embedded DisplayPort (eDP) 1.1a standard was adopted in February 2008. Its aims to define a standardized display panel interface for internal connections, i.e. graphic cards to notebook display panels.[4]

A preview of DisplayPort 1.2 was given at WinHEC 2008 and CES 2009. One planned improvement of this version is the doubling of the bandwidth, which would allow for increased resolutions, higher refresh rates, and deeper color depth. Other improvements include multiple independent video streams, support for stereoscopic 3D, increased AUX channel bandwidth, and addition of Apple Inc.'s Mini DisplayPort connector, which is much smaller and more appropriate for laptop computers and other small devices.[5]. The DisplayPort 1.2 standard is expected to be adopted in 2009.[6] [7]

[edit] DRM protection

DisplayPort includes optional DPCP (DisplayPort Content Protection) copy-protection from AMD, which uses 128-bit AES encryption, with modern cryptography ciphers. 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 content protection system to send data out to distant, unauthorized users.

Version 1.1 added the support of HDCP content protection.

[edit] Advantages over DVI

  1. Based on micro-packet protocol.
    • Allows easy expansion of the standard
    • Allows multiple video streams over single physical connection (in a future version)
  2. Designed to support internal chip-to-chip communication
    • Can drive display panels directly, eliminating scaling and control circuits and allowing for cheaper and slimmer displays
    • Aimed to replace internal LVDS links in notebook panels with a unified link interface
    • Compatible with low-voltage signalling used with 45 nm CMOS fabrication
  3. Supports both RGB and YCbCr encoding formats
  4. Auxiliary channel can be used for touch-panel data, USB links, camera, microphone, etc.
  5. Fewer lanes with embedded clock reduce RFI.
  6. Slimmer cables and a much smaller connector that doesn't require thumbscrews. Connector pins don't run the risk of bending if improperly handled.
  7. In low-light conditions or awkward under-desk connections, the DisplayPort connector is easier to connect when guided only by touch.

[edit] Relationship with HDMI

The DisplayPort website states that DisplayPort is expected to complement HDMI, a popular compact audio/video interface.[8] Most of the DisplayPort supporters are computer companies such as Dell which has released several computer monitors that support both DisplayPort and HDMI.[9][10]

DisplayPort has an advantage over HDMI in that it 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.[11]

There are a few advantages that HDMI has over DisplayPort such as support for the xvYCC color space, Dolby TrueHD and DTS-HD Master Audio bitstream support, Consumer Electronics Control (CEC) signals, and electrical compatibility with DVI.[12][13]

[edit] Technical specifications

  • 5.184 or 8.64 Gbit/s forward link channel supports high resolution displays with a single cable.
  • 8b/10b data transmission (up to 2.7 GHz symbol rate, up to 4 lanes).
  • Reduced bandwidth transmission for 15 metre cable (at least 1920x1080p60, 24 bpp).
  • Full bandwidth transmission for 2 metre cable.
  • Supports color depth of 6, 8, 10, 12 and 16 bits per color component.
  • Supports YCbCr color space (ITU-R BT.601-5 and BT.709-4), 4:2:2 chroma subsampling
  • Optional Dual-Mode support generates DVI/HDMI signal with a simple line-level conversion dongle. [14]
  • 128-bit AES DisplayPort Content Protection (DPCP) support, and support for 40-bit High-bandwidth Digital Content Protection (HDCP) from version 1.1 onwards.
  • Supports internal and external connections so that one standard can be used by computer makers reducing costs.[15]
  • Open and extensible standard to help with broad adoption.

General and technical overviews can be downloaded at DisplayPort.org.

† Data rates required by some common display modes and different vertical blanking methods, Gbit/s:

Resolution × frame rate × color depth No blanking GTF CVT CVT-RB
1920 × 1080 × 60 Hz × 24 bpp 2.99 4.15 4.15 3.33
1920 × 1200 × 60 Hz × 30 bpp 4.15 5.79 5.81 4.62
2560 × 1600 × 60 Hz × 30 bpp 7.37 10.44 10.46 8.06

Note: bpp is the number of bits for each pixel; for RGB and YCbCr 4:4:4, the bpp value is three times the bits per color component (bpc); for YCbCr 4:2:2 subsampling, the bpp value is twice the bpc value.

[edit] Products

Before being acquired by AMD, one of the supporters, ATI reported that they were expecting DisplayPort products in early 2007. On 25 July 2007, at AMD's Technology Analyst Day 2007, AMD renewed their commitment to supporting DisplayPort with the 780G 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.[16]

Genesis Microchip also announced DisplayPort products to be available in 2007,[17] as did Samsung.[18] A concept monitor by Dell implementing DisplayPort was demonstrated early May 2007.[19]

The Dell 3008WFP 30-inch (76 cm), released in January 2008 was the first monitor to support DisplayPort.[20][21] The Dell 2408WFP 24-inch (61 cm), which followed in April 2008,[22] Apple's LED Cinema Display, and HP's LP2275w, LP2475w, and LP2480zx monitors also support DisplayPort.

On 14 October 2008, Apple introduced several products featuring a Mini DisplayPort[23] as their sole video connector. Currently, all of their desktop and laptop computers use Mini DisplayPort. Their iMac and MacBook models use Mini DisplayPort as their sole video output port while their Mac Mini and Mac Pro models have both a Mini DisplayPort and either a DVI port (Mac Pro) or Mini DVI port (Mac Mini).

[edit] Supporters

The following companies have announced their intention, at one point or another, to implement or support DisplayPort: AMD/ATI, Analogix, Apple, ASRock, ASUSTeK, Circuit Assembly, Dell, Genesis Microchip, Hewlett-Packard, Hosiden Corporation, Intel, Integrated Device Technology, Japan Aviation Electronics, Lenovo, Luxtera, Molex, NVIDIA, NXP Semiconductors, Palit Microsystems Palit, Parade Technologies, Pioneer Corporation, Philips, Quantum Data, S3 Graphics, Samsung, Sparkle Computer, Texas Instruments, Tyco Electronics and Unigraf Oy.

[edit] References

  1. ^ Thomas Ricker (2007-01-03). "DisplayPort to support HDCP, too". Engadget. http://www.engadget.com/2007/01/03/displayport-to-support-hdcp-too/. Retrieved on 2007-12-22. 
  2. ^ Tuan Nguyen (2007-02-19). "The Future of HDMI". DailyTech. http://www.dailytech.com/The+Future+of+HDMI/article6098.htm. Retrieved on 2007-07-16. 
  3. ^ "Video Electronics Standards Association (VESA) Endorses Alternative to Copper Cables". Luxtera Inc.. 2007-04-17. http://www.luxtera.com/2007-04-17.html. Retrieved on 2008-10-15. 
  4. ^ "Embedded DisplayPort™ Standard Ready from VESA". VESA. 2009-02-23. http://www.displayport.org/news-presentations/press-releases/eDPpr.pdf. 
  5. ^ Tony Smith, "DisplayPort revision to get mini connector, stereo 3D", The Register, 13 January 2009
  6. ^ "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. 
  7. ^ "CES 2009 Press Event". VESA. 2009-01-11. http://www.displayport.org/news-presentations/press-releases/DP_CES_v3_09.pdf. 
  8. ^ "DisplayPort FAQ". DisplayPort website. http://www.displayport.org/FAQ/default.htm. Retrieved on 2008-06-19. 
  9. ^ 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 on 2008-06-18. 
  10. ^ 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 on 2008-06-18. 
  11. ^ "HDMI Adopter Terms". HDMI.org. http://www.hdmi.org/manufacturer/terms.aspx. Retrieved on 2008-06-23. 
  12. ^ "HDMI Specification 1.3a". HDMI Licensing, LLC.. 2006-11-10. http://www.hdmi.org. Retrieved on 2008-06-21. 
  13. ^ "DisplayPort 1.1a Standard". VESA.org. 2008-01-11. http://www.displayport.org. Retrieved on 2008-06-23. 
  14. ^ www.displayport.org/news-presentations/press-releases/DP_Computex_Final_08.pdf
  15. ^ DisplayPort/DVI/HDMI Comparison table, VESA DisplayPort Standard v1.0—Audioholics Home Theater Reviews and News.
  16. ^ AMD Press Release: AMD Receives First Ever DisplayPort Certification for PC Graphics. Retrieved 2008-03-20
  17. ^ "Genesis Microchip (GNSS) Q4 2006 Earnings Conference Call". Seeking Alpha. 2006-05-02. http://seekingalpha.com/article/9956. Retrieved on 2007-07-16. 
  18. ^ "Samsung touts development of first DisplayPort desktop LCD". TG Daily. 2006-07-25. http://www.tgdaily.com/content/view/33064/135/. Retrieved on 2007-07-25. 
  19. ^ "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 on 2007-07-16. 
  20. ^ Dell 3008WFP specifications, retrieved 2008-01-30
  21. ^ "Dell UltraSharp 3008WFP 30-Inch LCD Monitor". http://www.washingtonpost.com/wp-dyn/content/article/2008/01/03/AR2008010301753_pf.html. Retrieved on 2008-06-25. 
  22. ^ "Dell UltraSharp 2408WFP". http://cnet.nytimes.com/lcd-monitors/dell-ultrasharp-2408wfp/4505-3174_7-32886455.html. Retrieved on 2008-06-25. 
  23. ^ "Software Licensing and Trademark Agreement: Mini DisplayPort". http://developer.apple.com/softwarelicensing/agreements/minidisplayport.html. 

[edit] External links


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