DisplayPort

DisplayPort

DisplayPort connector
Type	Digital audio/video connector
Production history
Designer	VESA
Designed	May 2006
Produced	2008–present
General specifications
Hot pluggable	Yes
External	Yes
Audio signal	Optional; 1–8 channels, 16 or 24-bit linear PCM; 32 to 192 kHz sampling rate; maximum bitrate 49,152 kbit/s (6MB/s)
Video signal	Optional, maximum resolution limited by available bandwidth
Cable	3 meters for full bandwidth transmission over passive cable. 33 meters over active cable.
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.
Electrical
Signal	+3.3 V
Max. voltage	16.0 V
Max. current	500  mA
Data
Data signal	Yes
Bitrate	1.62, 2.7, or 5.4 Gbit/s data rate per lane; 1, 2, or 4 lanes; (effective total 5.184, 8.64, or 17.28 Gbit/s for 4-lane link); 1 Mbit/s or 720 Mbit/s for the auxiliary channel.
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 (3.3 V 500 mA)
Pins 13 and 14 may either be directly connected to ground or connected to ground through a pulldown device. 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(n) and 3(p) while lane 0 will be on pin 10(n) and 12(p).

DisplayPort is a digital display interface developed by the Video Electronics Standards Association (VESA). The VESA DisplayPort specification is royalty-free and is designed to replace VGA, DVI, and LVDS, but not HDMI.

The first version, 1.0, was approved by VESA on May 3, 2006. 1.1a was approved on April 2, 2007 followed by the current standard 1.2 on December 22, 2009.

Overview

DisplayPort protocol relies on packetized data transmission which is found in technologies like Ethernet, USB, and PCI Express. The DisplayPort connector supports 1, 2, or 4 differential data pairs (lanes) in a Main Link, each with a raw bit rate of 1.62, 2.7, or 5.4 Gbit/s per lane with self-clock running at 162, 270, or 540 MHz. Data is 8b/10b encoded where each 8 bits of information are encoded with a 10 bit symbol. The effective data rates after decoding are 1.296, 2.16, and 4.32 Gbit/s per lane (or 80% of the total).

Unlike legacy standards such as DVI, HDMI and LVDS, where some differential pairs are fixed to transmitting a clock signal and separate pairs are dedicated to RGB or YUV color channel data, the DisplayPort protocol is based on small data packets known as micro packets in the standard, which embed the clock signal within the data stream. The use of data packets allows DisplayPort to be extensible and scalable, meaning additional features can be added over time without significant changes to the interface itself, and variable number of differential pairs means that performance can easily scale with additional lanes.

DisplayPort supports both internal and external display connections, i.e. can be used as a connection to an external display device such as a computer monitor or television set, or as an internal link to the display panel in high-resolution monitors and televisions.

Displayport can transmit audio and video simultaneously, although both streams are optional and each can be transmitted without the other. The video packet supports 6 to 16 bits per color channel, and the audio packet supports up to 8 channels of 24 bit 192 kHz uncompressed PCM audio, which can encapsulate compressed audio formats in the audio stream. 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, as well as bi-directional USB data.

The DisplayPort signal is not compatible with DVI or HDMI. However dual-mode ports (marked with a DP++ logo) will transmit a single-link DVI or HDMI signal when they detect that an external passive adapter is attached. VGA and dual-link DVI require powered active adapters, which do not require dual-mode DisplayPorts (see compatibility with HDMI, DVI and VGA).

Versions

1.0 to 1.1

DisplayPort 1.0 supports a maximum of 8.64 Gbit/s data rate over a 2 meter cable. DisplayPort 1.1 also supports devices which implement alternative link layers such as fiber optic, allowing a much longer reach between source and display without signal degradation, although alternative implementations are not standardized. It also supports HDCP in addition to DisplayPort Content Protection (DPCP).

1.2

DisplayPort version 1.2 was approved on December 22, 2009. The most significant improvement of the new version is the doubling of the effective bandwidth to 17.28 Gbit/s, which allows 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), support for more color spaces including xvYCC, scRGB and Adobe RGB 1998, and Global Time Code (GTC) for sub 1 µs audio/video synchronisation. Also Apple Inc.'s Mini DisplayPort connector, which is much smaller and more appropriate for laptop computers and other small devices, is compatible with the new standard.

Companion standards

Mini DisplayPort (mDP) is a standard announced by Apple in the fourth quarter of 2008. Shortly after announcing the 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.

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. 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, 120 Hz sequential color monitors, and a new display panel control protocol that works through the AUX channel. 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. PSR mode allows GPU to enter power saving state in between frame updates by including framebuffer memory in the display panel controller.

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 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 digital TV system on a chip controller and the display panel's timing controller. It aims to replace currently used internal LVDS lanes with DisplayPort connection. 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. iDP features non-variable 2.7 GHz clock and is nominally rated at 3.24 Gbit/s data rate per lane, with up to 16 lanes in a bank, resulting in 6-fold decrease in wiring requirements over LVDS for a 1080p24 signal; other data rates are also possible. iDP was built with simplicity in mind and it doesn't support AUX channel, content protection, or multiple streams; however it does support frame sequential and line interleaved stereo 3D.

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.

Wireless DisplayPort is a standard which will enable DisplayPort 1.2 bandwidth and feature set for cable-free applications operating in 60 GHz radio band; this was announced on November 2010 by WiGig Alliance and VESA as a cooperative effort.

Specifications

Technical specifications

• Forward link channel with 1 to 4 lanes; effective data rate 1.296, 2.16, or 4.32 Gbit/s per lane (total 5.184, 8.64, or 17.28 Gbit/s for a 4-lane link)^†.
• 8b/10b encoding provides DC-balancing and Embedded Clock within serial channel (10 bit symbols, 20% coding overhead)
• Supports RGB (unspecified) and YCbCr (ITU-R BT.601-5 and BT.709-4) color spaces, 4:4:4 and 4:2:2 chroma subsampling
  • sRGB, Adobe RGB 1998, DCI-P3, RGB XR, scRGB, xvYCC, Y-only, Simple Color Profile (version 1.2)
• Supports color depth of 6, 8, 10, 12 and 16 bits per color component
• Optional 8-channel audio with sampling rates up to 24 bit 192 kHz, supports encapsulation of audio compression formats
• Bidirectional half-duplex AUX channel, 1 Mbit/s (v1.0) or optional 720 Mbit/s (v1.2)
• Supports stereoscopic 3D formats: frame sequential (v1.1a), field sequential, side-by-side, top-bottom, line interleaved, pixel interleaved and dual interface (v1.2)
• Optional dual-mode support generates TMDS and clock for single-link DVI/HDMI signaling with a simple line-level conversion dongle.
• Supports up to 63 video and audio streams with time-division transport multiplexing and hot-plug bandwidth allocation (from version 1.2)
• 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.

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

DRM

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). 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.

DisplayPort 1.1 added support for industry-standard 56-bit HDCP (High-bandwidth Digital Content Protection) revision 1.3, which has been compromised in September 2010 with the release of HDCP master key.

Comparisons

Compatibility with HDMI, DVI and VGA

Dual-mode DisplayPort

Dual-mode pin mapping

DisplayPort pins	DVI 1.0/HDMI mode
Main Link Lane 0	TMDS Channel 2
Main Link Lane 1	TMDS Channel 1
Main Link Lane 2	TMDS Channel 0
Main Link Lane 3	TMDS Clock
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)

Dual-mode DisplayPort can directly emit single-link HDMI and DVI signals using a simple passive adapter that adjusts for the lower voltages required by DisplayPort. When dual-mode chipset detects that a DVI or HDMI passive adapter is attached, it switches to DVI/HDMI mode which uses the 4-lane main DisplayPort link and the AUX channel link to transmit 3 TMDS signals, a Clock signal and Display Data Channel data/clock. Dual-mode ports are marked with the DP++ logo; most current DisplayPort graphics cards and monitors support this mode.

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; an active converter is needed for Dual-Link DVI (and analog component video such as VGA, since it employs digital to analog conversion). Active conversion can be powered by +3.3 V wire in the DisplayPort connector, but some active adapters require external power.

VESA foresees that all HDMI and DVI conversion will eventually be handled by active adapters which act as DisplayPort Sink devices, in order to facilitate easier updates to latest HDMI and DisplayPort specs, and support dual-link HDMI, DisplayPort connections with either fewer than 4 lanes or different data rates, and multiple DisplayPort streams. It should be noted that DVI 1.0 spec was finalized in 1999 and the DVI industry consortium has since disbanded, so future updates to DVI specification are unlikely; also, although dual-link HDMI Type B connector is defined in the HDMI specification, it has not seen any practical use as of 2012.

Advantages over DVI, VGA and LVDS

In December 2010 it was announced that several computer vendors and display makers including Intel, AMD, Dell, Lenovo, Samsung and LG would begin phasing out support for LVDS, VGA and DVI-I over the next few years moving forward with developing technologies DisplayPort and HDMI as their replacements.. One notable exception to the list of manufacturers is Nvidia, who has yet to announce any plans regarding future support of legacy interfaces.

Legacy interfaces such as VGA, DVI and LVDS have not kept pace, and newer standards such as DisplayPort and HDMI clearly provide the best connectivity options moving forward. In our opinion, DisplayPort 1.2 is the future interface for PC monitors, along with HDMI 1.4a for TV connectivity.

AMD, Dell, Intel Corporation, Lenovo, Samsung Electronics and LG. Dec 8, 2010.

DisplayPort has several advantages over VGA, DVI and LVDS.

• Open (except HDCP), royalty-free and extensible standard to help broad adoption
• Fewer lanes with embedded self-clock, reduced EMI with data scrambling and spread spectrum mode
• Based on a micro-packet protocol
  • Allows easy expansion of the standard with multiple data types
  • Flexible allocation of available bandwidth between audio and video
  • Multiple video streams over single physical connection (version 1.2)
  • Long-distance transmission over alternative physical media such as optical fiber (version 1.1a)
• Supports high resolution displays and multiple displays with a single cable
  • 17.28 Gbit/s of effective video bandwidth, enough for supporting 4 simultaneous 1080p60 displays (CEA-861 timings) or 2,560 × 1,600 × 30 bit @120 Hz (CVT-R timings)
• Designed to support internal chip-to-chip communication
  • Aimed at replacing internal LVDS links to display panels with a unified link interface
  • Compatible with low-voltage signaling used with sub-nanometer CMOS fabrication
  • Can drive display panels directly, eliminating scaling and control circuits and allowing for cheaper and slimmer displays
• Link training with adjustable amplitude and preemphasis adapts to differing cable lengths and signal quality
  • Reduced bandwidth transmission for 15 meter cable (at least 1920x1080p60, 24 bpp)
  • Full bandwidth transmission for 2 meter cable
• High-speed auxiliary channel for DDC, EDID, MCCS, DPMS, HDCP, adapter identification etc. traffic
  • Can be used for transmitting bi-directional USB, touch-panel data, CEC, etc.
• Self-latching connector

Comparison with HDMI

Although DisplayPort supports much of the same functionality as HDMI, it is expected to complement the HDMI interface, not replace it. 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 DisplayPort's supporters are computer companies including Apple, Dell, HP, Lenovo, Fujitsu, Toshiba and Acer, which intend DisplayPort to replace DVI, VGA and LVDS in their computers and monitors.

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. DisplayPort has more than twice the bandwidth with up to 21.6 Gbit/s (17.28 Gbits/s with overhead removed) as opposed to HDMI's 10.2 Gbits/s (8.16 Gbits/s with overhead removed), and can share this bandwidth with multiple streams of video and audio to separate devices.

DisplayPort in native mode lacks some features present in HDMI, such as support for the xvYCC color space (added in DisplayPort version 1.2) and Consumer Electronics Control (CEC) commands, which allow to control multiple devices through a single remote; VESA asserts that CEC commands can be transmitted over the AUX channel if needed. HDMI uses unique Vendor Specific Block structure which allows for specific features such as additional color spaces, however these can be defined by CEA EDID extensions.

Products

Left-hand side connectors on a Lenovo X220 laptop. From left to right, top to bottom: USB 3.0 host, VGA connector, Multi-mode DisplayPort connector, ExpressCard slot, USB 2.0 host

Since its introduction in 2006, DisplayPort has slowly gained popularity within the computer industry, and as of 2010, DisplayPort connectors are featured on many graphic cards, displays, and notebook computers.

ATI/AMD

AMD Graphics Product Group (former ATI Technologies) was the first company to release consumer products with a DisplayPort beginning with their 790G chipset and Radeon HD 2000 series graphics cards. The first were unveiled at AMD's Technology Analyst Day on July 25, 2007. AMD later implemented the DisplayPort on the GPU chip in Radeon HD 3600 and HD 3400 graphics products, unveiled at AMD Financial Analyst Day on 13 December 2007. These products received DisplayPort certification from VESA in March 2008.

In 2008, DisplayPort connectors were featured on many graphics cards based on the ATI/AMD HD 4000 series. In 2009, the HD 5000 series graphics cards incorporated a DisplayPort connector as a standard feature, along with two Dual-link DVI connectors and a HDMI connector. The Eyefinity versions can carry up to six Mini DisplayPort connectors. Support for DisplayPort audio was introduced by AMD in the Catalyst 9.12 hotfix.

As of February 2011, the latest HD 6000 series graphics cards feature support for DisplayPort 1.2, allowing daisy-chaining multiple monitors from the same connector. A DisplayPort hub containing three Dual-link DVI connectors is also available.

Apple

On 14 October 2008, Apple introduced several products featuring a Mini DisplayPort as the sole video connector. This connector was proprietary at that time. Later, with versions 1.1a and 1.2 of the specification, it became part of the standard. Between October 2009 and February 2011, all Mac models feature Mini DisplayPort connector; during that time iMac, MacBook, MacBook Air, MacBook Pro, and Xserve models used Mini DisplayPort as their sole video output while the Mac Mini and Mac Pro models had both a Mini DisplayPort and either a DVI port (Mac Pro) or an HDMI port (Mac Mini). On February 24, 2011 MacBook Pros began shipping with Thunderbolt (known previously by Intel codename Light Peak) which provides both DisplayPort and PCI Express functionality in a single port. On May 3, 2011 Apple introduced their first iMac lineup with Thunderbolt built in. The iMac 21 in (53 cm) received one and the iMac 27 in (69 cm) received two Thunderbolt ports.

Apple's 24 in (61 cm) and 27 in (69 cm) LED Cinema Displays feature Mini DisplayPort connector. The 27-inch iMac introduced in 2009 allowed the Mini DisplayPort to act as an input, turning the iMac into a standalone display. 2011 iMacs support this 'Target Display Mode' via the Thunderbolt port, but only when the source is also equipped with Thunderbolt.

Dell

A concept monitor by Dell implementing DisplayPort was demonstrated in early May 2007.

The Dell 3008WFP 30-inch (76 cm), released in January 2008 was the first monitor to support DisplayPort. The Dell 2408WFP 24-inch (61 cm) followed in April 2008. Many other Dell monitors also offer the DisplayPort interface, including four of their 'Professional' series and five of their 'UltraSharp' series monitors.

Hewlett Packard

The HP Elite L2201 21.5-inch (55 cm) released in June 2011 is the first monitor from Hewlett Packard to ship with a DisplayPort as the primary (and only) means of connectivity. HP EliteBook laptops provide both a VGA and a DisplayPort connector.

Lenovo

Lenovo offers DisplayPort connectors on some models.

Adopters and supporters

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

• Agilent
• Altera
• AMD Graphics Product Group
• Analogix
• Apple
• Astrodesign
• Broadcom Corporation
• Chi Mei Optoelectronics
• Chrontel
• Dell
• Display Labs
• Foxconn Electronics
• Genesis Microchip
• Hewlett-Packard
• Hosiden
• Hirose Electric Group
• Intel
• I-PEX
• Integrated Device Technology
• JAE Electronics
• Kawasaki Microelectronics (K-Micro)
• Lenovo
• LG Display
• Luxtera
• Molex
• NEC
• NVIDIA
• NXP Semiconductors
• Parade Technologies
• Realtek Semiconductor
• Samsung
• SMK
• STMicroelectronics
• SyntheSys Research Inc.
• Tektronix
• Texas Instruments
• TLi
• Tyco Electronics
• ViewSonic
• VTM

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

• Acer
• ASRock
• Biostar
• Chroma
• Circuit Assembly
• DataPro
• Eizo
• Fujitsu
• Gigabyte Technology
• Hall Research Technologies
• ITE Tech.
• Matrox Graphics
• Micro-Star International
• MStar Semiconductor
• Palit Microsystems Ltd.
• Pioneer Corporation
• S3 Graphics
• Toshiba
• Philips
• Quantum Data
• Sparkle Computer
• Unigraf

Market share

Figures from IDC show that DisplayPort was on 5.1 percent of commercial desktops and 2.1 percent on commercial notebooks in 2009. However, they predict that the figure for commercial desktops will grow to 89.5 percent, and for commercial notebooks to 95 percent by 2014. The main factor behind this is the phase out of VGA, and that both Intel and AMD will also stop supporting low-voltage differential signaling (LVDS), by 2013.

See also

• DiiVA
• HDBaseT
• HDMI
• Mini DisplayPort
• List of video connectors
• Thunderbolt

External links

• DisplayPort homepage
• Bridging the new DisplayPort standard
• Introducing the Panel Self Refresh Technology