Silicon Graphics, Incorporated

Silicon Grpahics, Inc.

Mark W Troeller

Henry Packard Moreton

Michael L Fuccio

Te-Li Lau

Bent Hagemark

Michael J Nielsen

Linda S Gardner

Charles F Tuffli, Iii

David K Barnett

A method and arrangement for a dma transfer mode having multiple transactions is provided. The invention generates a set of transaction entries for a DMA transfer each of which contains information related to the address and command instruction of a transaction. The transaction entries are stored in an address/cmd-output-FIFO. The invention negotiates for the control of the system bus. Upon gaining control of the bus, the commands and address relate to each transaction are sequentially place on the system bus. If the transaction is a read operation, data received back from the system bus is first stored in a data-in-FIFO before being sent to the desired destination. If the transaction is a write operation, the data to be transferred is first stored in a data-out-FIFO before being timely place on the system bus for transferring to the desired destination. In either case, the number of data words transferred is monitored to determine when a transaction is complete. The number of transactions carried out is also monitored to determine when a DMA transfer is complete.

Direct memory access apparatus for transferring a block of data having

A method and arrangement for separating interleaved luminance and chrominance color space components data in a single data stream with minimum CPU intervention is provided. In the separating circuit, the separating circuit receives as input a series of graphics/video image data composed of interleaved luminance and chrominance color space components at successive clock cycles. The separating circuit directs selected bytes of the graphics/video image data representing the luminance color space component to a first path wherein luminance component data received at two successive clock cycles are combined. Likewise, selected bytes of the graphics/video image data representing the chrominance color space component are directed to a second path wherein chrominance component data received at two successive clock cycles are combined. Then, the combined luminance and chrominance component data are output alternately. Conversely, a method and arrangement for interleaving luminance and chrominance color space components data in stored separately into a single data stream is also provided.

Circuit to separate and combine color space component data of a video

This relates to a general purpose circuit that maximizes the computing power of a Unix workstation or other computer system for processing image or other data in accordance with a selected one or ones of several alternative compression and decompression algorithms. This dynamically allocates system memory for storage of both compressed and uncompressed data and ensures adequate compression and decompression rates.

Compression and decompression scheme performed on shared workstation

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Visalia, CA, United States of America

Mark W Troeller