Audio-video data interface for a high speed communication link in a

Abstract

An interface architecture for interconnecting a plurality of video display devices together over a high speed digital communication link having limited bandwidth provides at each node for transmitting during a 'transmit mode'; (1) sequential pixels of digital data (COMVIDOUT) comprising separate luminance and chrominance fields, from a digital TV source associated with each display node which data represents a scaled video window, (2) the local system clock (SCLK), (3) vertical and horizontal communication sync signals (COMVSOUT and COMSHOUT), (4) luminance and chrominance clock enable signals (COMYOCE and COMCOCE) based on a scaling algorithm utilized in the transmitting video device to insure that both the proper pixels and the proper luminance and chrominance fields associated with these pixels are selected by the communications device for transmission. Further, the interface architecture at each display node provides for receiving during a 'receive mode', (5) video input data pixels (COMVIDIN), (6) a video input data clock enable signal from the communications adapter (COMVINCE) which controls the storage of the received video data window in the local frame buffer, (7) horizontal and vertical video input sync signals from the communications adapter (COMHSIN and COMVSIN) for properly synchronizing the storing of the received video input data from the communications adapter into the frame buffer beginning ata predetermined address therein. The system utilizes, to a great extent, exisiting hardware in conventional video display device architectures and associated communications adapters such that a versatile generally applicable transmission system is achievable requiring a minimum of additional control hardware and software.