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DisplayPort

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DisplayPort
Type Digital audio/video connector
Production history
Designer VESA
Designed May 2006
Produced 2008
General specifications
Hot pluggable Yes
External Yes
Audio signal Optional, 1-8 channels, 16 or 24-bit linear PCM, 48/96/192 kHz sampling rate, uncompressed, max. 6.144 Mbit/s bit rate
Video signal Optional, maximum resolution unlimited
Cable Maximum length 15 metres for video transmission (resolution at least 1920×1080p60 at 24bpp),
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. / 30/20 pins for internal connections between graphics engines and built-in flat panels.
Electrical
Signal +3.3 V
Max. voltage 16.0 V
Max. current 500mA
Data
Data signal Yes
Bitrate 1.62 or 2.7 GHz symbol rate, 1/2/4 lanes (total 5.184 or 8.64 Gbit/s data rate) plus 1 Mbit/s for AUX CH (for additional data)
Protocol mini-packet
Pinout
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 (approved May 2006, current version 1.1a approved on January 11, 2008) put forth by the Video Electronics Standards Association (VESA). It defines a new license-free, 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.

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 10x 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).

A preview of DisplayPort 1.2 was given at WinHEC 2008. One planned improvement of this version is an increase in the bandwdith which will be decided on by VESA. The bandwidth increase would allow for increased resolutions, higher refresh rates, and deeper color depth. The DisplayPort 1.2 standard is expected to be adopted in 2009.[4]

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.

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 control circuits and allowing for cheaper and slimmer displays
    • Aimed to replace internal LVDS links in notebook panels with a unified link interface
  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. The DisplayPort connector is easier to connect when guided only by touch.

Advantages compared to HDMI

  1. DisplayPort does not require licensing or royalty payments.

Disadvantages compared to HDMI

  1. No xvYCC color space support.
  2. No Dolby TrueHD or DTS-HD Master Audio bitstream support.
  3. No support for Consumer Electronics Control signals.

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, 8B/10B modulation).
  • 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
  • Supports legacy signal streams (analog and DVI/HDMI); backward compatibility achieved with adapters/dongles
  • 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.[5]
  • Open and extensible standard to help with broad adoption.

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

† Not taking into account blanking (20-30% overhead for GTF, 10-20% for CVT-RB):
   1920 × 1080 × 60fps × 24bpp = 3.0 Gbit/s,
   1920 × 1200 × 60fps × 30bpp = 4.1 Gbit/s,
   2560 × 1600 × 60fps × 30bpp = 7.4 Gbit/s,
   4096 × 2160 × 24fps × 36bpp = 7.7 Gbit/s,
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.

Products

Before being acquired by AMD, one of the supporters, ATI reported that they were expecting DisplayPort products in early 2007. On 2007-07-25, 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 2007-12-13, providing support without external transmitters. These products obtained certification from VESA on March 19.[6]

Genesis Microchip also announced DisplayPort products to be available in 2007,[7] as did Samsung.[8] A concept monitor by Dell implementing DisplayPort was demonstrated early May 2007.[9]

The Dell 3008WFP 30-inch (76 cm), released in January 2008 was the first monitor to support DisplayPort.[10][11] The Dell 2408WFP 24-inch (61 cm), which followed in April 2008,[12] and HP's LP2475w monitor also support DisplayPort.

On October 14, 2008, Apple introduced several products featuring a Mini DisplayPort[13] as their sole video connector. Apple indicated that this was a first step in transitioning their line of products to DisplayPort technology.[14]

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, Philips, Quantum Data, Samsung, Sparkle Computer, Texas Instruments, and Tyco Electronics.

References

  1. ^ Thomas Ricker (2007-01-03). "DisplayPort to support HDCP, too". Engadget. Retrieved 2007-12-22. {{cite web}}: Check date values in: |date= (help)
  2. ^ Tuan Nguyen (2007-02-19). "The Future of HDMI". DailyTech. Retrieved 2007-07-16. {{cite web}}: Check date values in: |date= (help)
  3. ^ "Video Electronics Standards Association (VESA) Endorses Alternative to Copper Cables". Luxtera Inc. 2007-04-17. Retrieved 2008-10-15. {{cite web}}: Check date values in: |date= (help)
  4. ^ "WinHEC 2008 GRA-583: Display Technologies". Microsoft. 2008-11-06.
  5. ^ DisplayPort/DVI/HDMI Comparison table, VESA DisplayPort Standard v1.0 — Audioholics Home Theater Reviews and News.
  6. ^ AMD Press Release: AMD Receives First Ever DisplayPort Certification for PC Graphics. Retrieved 2008-03-20
  7. ^ "Genesis Microchip (GNSS) Q4 2006 Earnings Conference Call". Seeking Alpha. 2006-05-02. Retrieved 2007-07-16. {{cite web}}: Check date values in: |date= (help)
  8. ^ "Samsung touts development of first DisplayPort desktop LCD". TG Daily. 2006-07-25. Retrieved 2007-07-25. {{cite web}}: Check date values in: |date= (help)
  9. ^ "Dell Shows Off Super-Slim Display Port LCD Monitor". Gearlog.com. 2007-05-17. Retrieved 2007-07-16. {{cite web}}: Check date values in: |date= (help)
  10. ^ Dell 3008WFP specifications, retrieved 2008-01-30
  11. ^ "Dell UltraSharp 3008WFP 30-Inch LCD Monitor". Retrieved 2008-06-25.
  12. ^ "Dell UltraSharp 2408WFP". Retrieved 2008-06-25.
  13. ^ http://developer.apple.com/softwarelicensing/agreements/minidisplayport.html. {{cite web}}: Missing or empty |title= (help)
  14. ^ Cohen, Peter (2008-10-17). "DisplayPort: What You Need to Know". PC World. PC World Communications. Retrieved 2008-10-17. Apple didn't just introduce new laptops Tuesday; it also introduced a new term to the vocabulary of Mac users—DisplayPort. The Mini DisplayPort found on new MacBooks, the refreshed Macbook Air and 15-inch MacBook Pros replaces the DVI and mini-DVI interfaces found on older models.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=DisplayPort&oldid=263263284"