Digital Visual Interface

The Digital Visual Interface (DVI) is a video interface standard designed to maximize the visual quality of digital display devices such as flat panel LCD computer displays and digital projectors. It was developed by an industry consortium, the Digital Display Working Group (DDWG).

About the Connector

The DVI connector usually contains pins to pass the DVI-native digital video signals. In the case of dual-link systems, additional pins are provided for the second set of data signals. The DVI connector may also incorporate pins to pass through the legacy analog signals using the VGA standard. This feature was included in order to make DVI universal, as it allows either type of monitor (analog or digital) to be operated from the same connector. The DVI connector on a device is therefore given one of three names, depending on which signals it implements: DVI-D (digital only) DVI-A (analog only) DVI-I (digital & analog) The connector also includes provision for a second data link for high resolution displays, though many devices do not implement this. In those that do, the connector is sometimes referred to as DVI-DL (dual link). DVI is the only widespread standard that includes analog and digital transmission options in the same connector. Competing standards are exclusively digital: these include a system using low-voltage differential signalling (LVDS), known by its proprietary names FPD (for Flat-Panel Display) Link and FLATLINK; and its successors, the LVDS Display Interface (LDI) and OpenLDI.

One oversight in DVI is that USB signals were not incorporated into the connector. This has been addressed in the VESA M1-DA connector used by InFocus on their projector systems, and in the now-defunct Apple Display Connector used by Apple Computer. The VESA M1 connector is essentially the VESA Plug & Display (P&D) connector, which was itself originally named the Enhanced Video Connector (EVC). The pinout of the Apple Display Connector is electrically compatible with the VESA P&D/M1, but physically the shell of the connector is a different shape.

Some new DVD players, TV sets (including HDTV sets) and video projectors have DVI/HDCP connectors; these are physically the same as DVI connectors but transmit an encrypted signal using the HDCP protocol for copyright protection. Computers with DVI video connectors can use many DVI-equipped HDTV sets as a display.

Specifications

Digital

• Minimum clock frequency: 21.76 MHz
• Maximum clock frequency in single link mode: Capped at 165 MHz (3.7 Gbit/s)
• Maximum clock frequency in dual link mode: Limited only by cable quality (more than 7.4 Gbit/s)
• Pixels per clock cycle: 1 (single link) or 2 (dual link)
• Bits per pixel: 24
• Example display modes (single link):
• HDTV (1920 × 1080) @ 60 Hz with 5% LCD blanking (131 MHz)
• UXGA (1600 × 1200) @ 60 Hz with GTF blanking (161 MHz)
• WUXGA (1920 × 1200) @ 60 Hz (154 MHz)
• SXGA (1280 × 1024) @ 85 Hz with GTF blanking (159 MHz)
• Example display modes (dual link):
• QXGA (2048 × 1536) @ 75 Hz with GTF blanking (2×170 MHz)
• HDTV (1920 × 1080) @ 85 Hz with GTF blanking (2×126 MHz)
• WQXGA (2560 × 1600) pixels (30" LCD)
• WQUXGA (3840 × 2400) @ 41 Hz
• GTF (Generalized Timing Formula) is a VESA standard.

Analog

• RGB bandwidth: 400 MHz at -3 dB