Displayport is a relatively new digital video and audio interface, developed to replace VGA, DVI, and LVDS (low voltage differential signaling). It allows computers and other digital devices to connect to display devices such as computer monitors. At the same time, it has the capability to transmit audio, USB and other forms of data.

VGA was the standard video interface for computers for a large number of years. DVI, which is compatible with the newer HDMI standard has replaced it in more recent years, although most computers are still manufactured with VGA connections as well as DVI. As Displayport gains a larger acceptance, we should see these two formats gradually be phased out.

The Video Electronics Standards Association (VESA) is the developer and owner of Displayport, licensing it on a royalty-free basis, which differentiates Displayport from other digital interfaces. VESA was created as an industry-wide standards body by a number of electronics manufacturers. Currently, there are over 40 major electronics manufacturers involved in VESA, specifically in the manufacture and use of devices that use the Displayport interface.

Displayport is unique in that it is the first display interface to rely on packetized data transmission. This allows a higher video resolution with a lower number of connector pins. One way that it eliminates unnecessary pins is by containing the clock signal integral in the information packet, instead of requiring a clock line to synchronize devices.

Although the interface contains both audio and video channels, they are capable of being used separately, or simultaneously. The data transmission capacity of Displayport is even higher than HDMI or DVI; providing over twice the bandwidth of HDMI.


Displayport Adaptability

One of the benefits of using Displayport is the availability of readily adapting it to other video interfaces. Adapters exist to convert Displayport to HDMI, DVI and VGA, all three of the other common video interfaces used with computer and digital equipment. This allows computers that have the Displayport interfaces to be used with all existing video equipment, including monitors, flat-panel displays and video projectors.

A dual-mode Displayport version exists, which allows data to be transmitted in the same format as HDMI, DVI and VGA, facilitating the use of simple adapters for connection of Displayport equipment to other devices. By designing Displayport to be compatible with the other major video interfaces on the market, VESA made it easy for this interface to integrate into existing systems and designs.


Displayport Performance

Displayport is designed specifically to be a high performance interface, matching and surpassing the capability of modern video equipment. It provides compact external connection with optional latching, which works well with today’s low-voltage digital equipment. The interface is designed to go well beyond HDMI, being capable of handling WQXGA at 10 bit color (2560 x 1600 pixels).

Passive Displayport cables can transmit up to 15 meters. For signal transmission beyond this distance, active cable systems, which amplify the signal are used.


Displayport Availability

While still considered a relatively new interface, many new computers are being designed with Displayport connections. This is especially true of laptop computers, where the compact design of Displayport makes it much easier to use on slimline laptops than either VGA or DVI connections.

While not all equipment is currently manufactured with Displayport connections, over 60 different companies have announced their intention to implement Displayport on future designs.

Rich Murphy.