DVI (Digital Visual Interface), digital video interface. It was launched in 1999 by the DDWG (Digital Display Working Group), which is composed of companies such as Silicon Image, Intel, Compaq, IBM, HP, NEC, and Fujitsu. Interface standard.
DVI is based on TMDS (Transition Minimized Differential Signaling), which converts the minimum differential signal technology to transmit digital signals. TMDS uses advanced encoding algorithms to encode 8-bit data (each channel's primary color signal in R, G, and B) to 10 bits using minimum conversion. (Including line and field synchronization information, clock information, data DE, error correction, etc.) After DC balance, differential signals are used to transmit data. It has better electromagnetic compatibility performance than LVDS and TTL, and can be used for low-cost applications. Cables enable long-distance, high-quality digital signal transmission. The Digital Video Interface (DVI) is an international open interface standard that has a wide range of applications on PCs, DVDs, HDTVs, high-definition projectors, and other devices.
In order to achieve the high-definition display requirements, the scan generally uses 1080i@60Hz format (ie, interlaced scanning, line frequency 33.75kHz, field frequency 60Hz, pixel frequency 74.25MHz), in order to reduce the line frequency conversion in real applications, all the video input formats ( Such as 480P, 576P, 720P, etc.) are converted to 1080i@60Hz format output by format conversion (Scale, De-interlace, etc.), that is, multi-frequency normalization. The DVI interface discussed in this article considers the application based on the above digital television standard.
Adding DVI interface to digital TV is relatively simple. Considering hardware circuit, one is adding DVI decoding part at the interface, and the other is providing a data channel at the back end. If the original program of the TV has A/D conversion and corresponding data at the later stage. Processing channels, then the DVI interface decoding output data can be shared with it, because in the case of a certain digital signal format, the code rate, line frequency, field frequency, clock is consistent.