An Overview of Current Display Interfaces

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An Overview of

Current Display

Interfaces

Table of Contents:

Introduction ...........................................................................................1

The Future of Display Interfaces ...............................................................2

Monitor and TV Market Trends ........................................................................ 2

VGA ............................................................................................................... 4

DVI ................................................................................................................. 5

HDMI .............................................................................................................. 6

DisplayPort ..................................................................................................... 7

Display Interface Comparison Table.........................................................8

Introduction

Concerns over image quality, the near-complete replacement of the CRT by LCDs

and other new display technologies, and growing concerns over content protection

are prompting significant changes in display interface technology. Although PCs

will likely continue to use the VGA interface in the short run, long-term, the future is

moving to all-digital.

Various proposals, including improved analog connectors, hybrid digital-plus-

analog approaches, and several all-digital interfaces have been put forth since the

early 1990s. One, the Digital Visual Interface (DVI), which is available in both

analog plus digital and digital-only forms, has seen reasonable success in higher-

end PC products, but has not managed to take the majority of the market from the

VGA. Consumer HDTV products have started a migration from the various analog

connections to the all-digital High Definition Multimedia Interface (HDMI) – but

HDMI shows no signs of adoption in PCs, except for connection to TV products.

Most recently, the DisplayPort (DP) connection now appears to be the long-term

future for the PC industry, and possibly the converged standard for both PC and CE

products.

This paper gives an overview of the four leading display interfaces – VGA, DVI,

HDMI, and DisplayPort – in the PC industry, and includes a brief history of each,

their basic characteristics and pinouts, and provides a comparison of each

interface’s features and performance.

Summary of content (8 pages)

PAGE 1
An Overview of Current Display Interfaces Table of Contents: Introduction ...........................................................................................1 The Future of Display Interfaces ...............................................................2 Monitor and TV Market Trends ........................................................................2 VGA ...............................................................................................................4 DVI .......................
PAGE 2
The Future of Display Interfaces Monitor and TV Market Trends The following trends seem likely over the next 3-5 years in the monitor and TV markets.  While there will continue to be a trend to larger-sized monitors, the upper end of this market will not increase significantly in terms of size – the majority of desktop monitors will remain under 30-inch diagonal.
PAGE 3
 The HDMI connector has completely displaced DVI in consumer HDTV gear. HDMI will continue to grow in popularity in the consumer market for both HD and digital SDTV equipment and start to displace the older analog-only TV interfaces (such as S-Video). HDMI, however, is very unlikely to see much use as a PC monitor connection or graphics output, except for TV connectivity purposes and in the short term as a smaller DVI-compatible output for some notebook PCs.
PAGE 4
VGA The VGA connector – named for the Video Graphics Array standard introduced by IBM for the original Personal Computer products in 1987, has been the most successful PC monitor interface to date in the computer industry. In use now for almost 25 years, the VGA (also known as the 15HD connector, for15-pin high-density D-subminiature) remains the standard analog video interface of the PC industry, but is beginning to experience limitations.
PAGE 5
DVI The Digital Visual Interface, or DVI, standard was published by the Digital Display Working Group (DDWG) in 1999. The DDWG was an ad-hoc consortium of seven PC-industry companies – HP, Compaq, Intel, IBM, NEC, Fujitsu, and Silicon Image (the developer of the Transition Minimized Differential Signaling or TMDS electrical interface on which the standard was based). DVI became the first reasonablysuccessful digital display interface for PC monitors.
PAGE 6
HDMI After the DDWG failed to agree on a specification for a consumer version of the DVI specification, Silicon Image formed a new consortium to develop a digital interface specifically for the consumer TV market, this time with six leading CE companies. The result was the High Definition Multimedia Interface, or HDMI.
PAGE 7
DisplayPort In late 2005, another consortium of computer and display electronics manufacturers – HP, Dell, Philips, NVIDIA, ATI (now AMD), Samsung, and Genesis Microchip – brought a new digital display interface specification to the Video Electronics Standards Association (VESA) as a proposed new standard. About a year later, VESA published the original DisplayPort standard. Since then, the original group of promoters has expanded to include Intel and Lenovo, and the spec was revised to the 1.
PAGE 8
Display Interface Comparison Table Table 5. Display Interface Comparison Table VGA DVI HDMI DisplayPort Connector Type 15-pin high-density D-subminiature, often with thumbscrews for latching Unique 24-pin, 3row main field, DVI-I adds 4-pin micro-cross section. Unique 19-pin dual-row connector (HDMI-A) Unique 20-pin dualrow connector with latch Capacity/ Bandwidth Undefined; usually ok to about 150 MHz pixel rates. 4.8 Gb/s (single link); 9.6 Gb/s (dual-llink) 4.8 Gb/s thru HDMI 1.2; up to 9.