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Digital Visual Interface (DVI) and other digital display interfaces.

Digital Visual Interface (DVI) and other digital display interfaces

The push is on to make displays digital, whether they’re legacy CRTs (Cathode Ray Tubes) or newer LCDs (Liquid Crystal Displays)—because a digital monitor provides both excellent picture quality and higher transfer bandwidths.

Three main types of DVI's

There are three main types of digital video interfaces: P&D, DFP, and DVI. P&D (Plug & Display, also known as EVC), the earliest of these technologies, supports both digital and analogue RGB connections and is now used primarily on projectors. DFP ( Digital Flat-Panel Port) was the first digital-only connector on displays and graphics cards; it’s being phased out.

Two types of DVI Connectors

There are two types of DVI connectors in use: DVI-D and DVI-I. DVI-D is a digital-only connector like DFP, but it offers much faster data transfer and higher resolution along with power-saving modes. DVI-I handles both digital and analogue connections like P&D does, but it’s somewhat smaller. Manufacturers such as Intel®, IBM, Compaq®, HP®, Fujitsu®, and NEC® are backing DVI technology, particularly the DVI-I connector type because it can do what previously required separate analogue and digital connectors.


All these standards are based on transition-minimised differential signalling (TMDS). In a typical single-line digital signal, voltage is raised to a high level and decreased to a low level to create transitions that convey data. TMDS uses a pair of signal wires to minimise the number of transitions needed to transfer data. When one wire goes to a high-voltage state, the other goes to a low-voltage state. This balance increases the data-transfer rate and improves accuracy.

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