Thread: Unified Display Interface

Managed by a working group of several major manufacturers, the Unified Display Interface (Um) was designed for low-cost and volume production. At
present, the DVI interface is too costly for mass integration into PC chipsets. um offers a smaller, cheaper connector that, like HDMI, is simple to plug in with one hand. All the functions of DVI, including HDCP support, are available in UDI.

Unlike HDMI or Displayport, um has no audio capability. It's aimed at PCs, where it is hoped that it will become a cost-effective replacement for DVI. And because of its low cost, the promoters hope that digital-only, flat-panel monitors will be made without the need for legacy analogue VGA connectors and hardware.

Far from competing with HDMI, um is designed to be able to share a single connector supporting both standards. Where both standards are supported in a single device, it will detect whether a um or HDMI device has been connected and automatically switch to the correct protocol.



Although um doesn't include some of HDMI's features, such as audio, the spec allows for their optional support. This means it's permissible to create a um device that can connect to an HDMI device with full audio support, although such functionality is never required by the um spec.

um has features to help it work well when connecting to DVI displays, although the UDI spec says that implementing these features will not guarantee DVI interoperability without additional design, implementation and testing. um, like Displayport, also has an internal form.

Again, this will create greater compatibility between components, and it will allow simpler designs that do not need to convert between internal and external signalling systems, meaning less hardware and cheaper monitors. Like HDMI 1.3, um supports higher bit¬depths than DVI, enabling support for billions of colours. It's also capable of far higher bandwidths than either of these two standards, allowing for much higher image resolutions in the future.