International Business Machines Corporation

Leland D Richardson

William Robert Lee

Paul Mark Schanely

Lawrence D Curley

Dennis P Cheney

Ronald S Svec

David C Tannenbaum

Andrew D Bowen

Robert Spencer Horton

Bruce C Hempel

An integrated digital video system is configured to implement picture-in-picture merging of video signals from two or more video sources, as well as selective overlaying of on-screen display graphics onto the resultant merged signal. The picture-in-picture signal is produced for display by a television system otherwise lacking picture-in-picture capability. The digital video system can be implemented, for example, as an integrated decode system within a digital video set-top box or a digital video disc player. In one implementation, a decompressed digital video signal is downscaled and merged with an uncompressed video signal to produce the multi-screen display. The uncompressed video signal can comprise either analog or digital video. OSD graphics can be combined within the integrated system with the resultant multi-screen display or only with a received uncompressed analog video signal.

Integrated video processing system having multiple video sources and implementing picture-in-picture with on-screen display graphics

A programmable bi-directional external graphics/video (EGV) port for a video decode system chip having a video decoder and an internal digital display generator circuit is provided. The programmable EGV port employs a fixed number of signal input/output (I/O) pins on the video decode system chip while providing a plurality of connection configurations for an external graphics controller, an external digital display generator circuit and an external digital multi-standard decoder to the video decoder or the internal digital display generator circuit of the chip. The EGV port includes receiver/driver circuitry for accommodating in parallel a plurality of input/output signals, including pixel data signals and corresponding synchronization signals, as well as a programmable port controller adapted to be coupled between the receiver/driver circuitry and an internal bus of the video decode system allowing access to at least one of the video decoder and the internal digital display generator circuit. The programmable port controller is programmable to either receive data into the video decode system chip or to send data out from the video decode system chip.

Programmable external graphics/video port for digital video decode system chip

A variable clock generator includes a clock multiplier that generates from a reference clock at least two clock signals which are out of phase with each other and a clock divider which receives a plurality of divider patterns and which receives at least two clock signals from the clock multiplier. The clock divider generates an output clock based on the divider patterns and the clock signals. In a particular embodiment, the clock divider includes a plurality of loadable linear feedback shift registers each having an output. An EXCLUSIVE OR gate that is responsive to the outputs of the linear feedback shift registers then EXCLUSIVE ORs the outputs of the linear feedback shift registers to produce the output clock. Preferably, the size of the linear feedback shift registers corresponds to the size of the divider patterns.

Dynamically configurable variable frequency and duty cycle clock and

Hardware logic and processing methods for enhanced data manipulation within a graphics display system are described. The graphics display system includes a graphics processor sub-system and a rendering subsystem which are serially connected for pipeline processing of an interleaved stream of commands and data. One or more status bits or XBITs are defined within each rasterizer of a multi-rasterizer rendering sub-system. An XBIT, which may comprise a ZBIT, a UBIT, or an RBIT, etc., provides a mechanism for introducing execution of various logic functions within the rendering sub-system portion of the computer graphics adapter. Corresponding data processing methods are also described.

Decision variable hardware logic and processing methods for graphics

A method and apparatus for the management of the data associated with multiple graphics contexts in a computer graphics rendering system. Graphics contexts are built by graphics engines and selectively saved into a context save RAM. Context switches are managed either by modifying a context base pointer to address a new section of the context save RAM, or by writing out a portion of the context save RAM to external storage and reading in a replacement context from external storage. The writing and reading process are managed by a control processor allowing the graphics engines to switch context at the same time. New contexts read from external storage automatically cause regeneration of downstream rasterization parameters.

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Apex, NC, United States of America

Leland D Richardson