Abstract: The present invention provides for asynchronous DMA command completion notification in a computer system. A command tag, associated with a plurality DMA command is generated. A DMA data movement command having the command tag is grouped with another DMA data movement command having the command tag. DMA commands belonging to the same tag group are monitored to see whether all DMA commands of the same tag group are completed.

Abstract: The present invention provides for atomic update primitives in an asymmetric single-chip heterogeneous multiprocessor computer system having a shared memory with DMA transfers. At least one lock line command is generated from a set comprising a get lock line command with reservation, a put lock line conditional command, and a put lock line unconditional command.

Abstract: A system and method are provided for improving performance of a computer system by providing a direct data transfer between different processors. The system includes a first and second processor. The first processor is in need of data. The system also includes a directory in communication with the first processor. The directory receives a data request for the data and contains information as to where the data is stored. A cache is coupled to the second processor. An internal bus is coupled between the first processor and the cache to transfer the data from the cache to the first processor when the data is found to be stored in the cache.

Abstract: A computer architecture and programming model for high speed processing over broadband networks are provided. The architecture employs a consistent modular structure, a common computing module and uniform software cells. The common computing module includes a control processor, a plurality of processing units, a plurality of local memories from which the processing units process programs, a direct memory access controller and a shared main memory. A synchronized system and method for the coordinated reading and writing of data to and from the shared main memory by the processing units also are provided. A hardware sandbox structure is provided for security against the corruption of data among the programs being processed by the processing units. The uniform software cells contain both data and applications and are structured for processing by any of the processors of the network. Each software cell is uniquely identified on the network.

Abstract: A system and method are provided for efficiently processing data with a cache in a computer system. The computer system has a processor, a cache and a system memory. The processor issues a data request for streaming data. The streaming data has one or more small data portions. The system memory is in communication with the processor. The system memory has a specific area for storing the streaming data. The cache is coupled to the processor. The cache has a predefined area locked for the streaming data. A cache controller is coupled to the cache and is in communication with both the processor and the system memory to transmit at least one small data portion of the streaming data from the specific area of the system memory to the predefined area of the cache when the one small data portion is not found in the predefined area of the cache.

Abstract: The present invention provides for determining an MRU or LRU way of a partitioned cache. The partitioned cache has a plurality of ways. There are a plurality of partitions, each partition comprising at least one way. An updater is employable to update a logic table as a function of an access of a way. Partition comparison logic is employable to determine whether two ways are members of the same partition, and to allow the comparison of the ways correlating to a first matrix indices and a second matrix indices. An intersection generator is employable to create an intersection box of the memory table as a function of a first and second matrix indices. Access order logic is employable to combine the output of the intersection generator, thereby determining which way is the most or least recently used way.

Abstract: A processor-cache operational scheme and topology within a multi-processor data processing system having a shared lower level cache (or memory) by which the number of coherency busses is reduced and more efficient snoop resolution and coherency operations with the processor caches are provided. A copy of the internal (L1) cache directory is provided within the lower level (L2) cache or memory. The snoop operations and coherency maintenance operations of the L1 directory are completed by comparing the snoop addresses with the address tags of the copy of the L1 directory in the L2 cache. Updates to the coherency states of the copy of the L1 directory are mirrored in the L1 directory and L1 cache. This eliminates the need for the individual coherency buses of each processor that is coupled to the L2 cache and speeds up coherency operations because the snoops do not have to be transmitted to the L1 caches.

Abstract: A system and method are provided for improving performance of a computer system by providing a direct data transfer between different processors. The system includes a first and second processor. The first processor is in need of data. The system also includes a directory in communication with the first processor. The directory receives a data request for the data and contains information as to where the data is stored. A cache is coupled to the second processor. An internal bus is coupled between the first processor and the cache to transfer the data from the cache to the first processor when the data is found to be stored in the cache.

Abstract: Memory management in a computer system is improved by preventing a subset of address translation information from being replaced with other types of address translation information in a cache memory reserved for storing such address translation information for faster access by a CPU. This way, the CPU can identify the subset of address translation information stored in the cache.

Abstract: A system and method are provided for directly accessing a cache for data. A data transfer request is sent to a system bus for transferring data to a system memory. The data transfer request is snooped. A snoop request is sent to a cache. It is determined whether the snoop request has a valid entry in the cache. Upon determining that the snoop request has a valid entry in the cache, the data is caught and sent to the cache for update.

Abstract: The present invention renders a triangular mesh for employment in graphical displays. The triangular mesh comprises triangle-shaped graphics primitives. The triangle-shaped graphics primitives represent a subdivided triangular shape. Each triangle-shaped graphics primitive shares defined vertices with adjoining triangle-shaped graphics primitives. These shared vertices are transmitted and employed for the rendering of the triangle-shaped graphics primitives.

Abstract: The present invention provides data encryption for a differential bus employing transitional coding. The present invention maps, encodes and encrypts input data as a logic status for a given bus transfer cycle. The mapping, encoding and encrypting of the input data changes from bus transfer cycle to bus transfer cycle. The mapping, encoding and encrypting is a function of a pseudo-random number. A logic status is differentially transmitted from a bus transmitter to a bus receiver, to be mapped, decrypted and decoded as the corresponding output data.

Abstract: The present invention provides employing differential transitional encoding with a differential bus. Employing the differential transitional encoding comprises dividing the differential bus into one or more groups comprising four bus lines. Employment of the differential bus also comprises asserting half the bus lines of a group during a bus data transfer, thereby defining an asserted set of bus lines and a de-asserted set of bus lines. The method and system further comprises transmitting data by differentially driving two of the bus lines, one bus line per set, by de-asserting one of the bus lines of the asserted set, and asserting one of the bus lines of the de-asserted set.

Abstract: A method and apparatus in a data processing system for asynchronous context switching. Requests of graphics processes are received to process graphics data for display in a queue in the graphics adapter. A current context is switched for a first graphics process to a new context for a second graphics process only in response to requests received in the queue. In this manner, the graphics adapter is able to continuously process commands in the queue instead of waiting for new commands to be sent after each context switch.

Abstract: A frame buffer system includes a first frame buffer containing a first set of pixels, and a second frame buffer containing a second set of pixels. A first register is connected to an output of the first frame buffer, wherein the first register a number of pixels is stored in which a group of bytes of data is stored for each of the number of pixels. A second register is connected to an output of the second frame buffer, wherein the second register a number of pixels is stored in which a group of bytes of data is stored for each of the number of pixels. A selection logic is connected to the first frame buffer and to the second frame buffer. The selection logic selectively selects pixels to be read from the first frame buffer and the second frame buffer into the first register and the second register. A multiplexer has a first input connected to an output of the first register, a second input connected to an output of the second register, and an output configured for connection to a digital to analog converter.

Abstract: A processor-cache operational scheme and topology within a multi-processor data processing system having a shared lower level cache (or memory) by which the number of coherency busses is reduced and more efficient snoop resolution and coherency operations with the processor caches are provided. A copy of the internal (L1) cache directory is provided within the lower level (L2) cache or memory. The snoop operations and coherency maintenance operations of the L1 directory are completed by comparing the snoop addresses with the address tags of the copy of the L1 directory in the L2 cache. Updates to the coherency states of the copy of the L1 directory are mirrored in the L1 directory and L1 cache. This eliminates the need for the individual coherency buses of each processor that is coupled to the L2 cache and speeds up coherency operations because the snoops do not have to be transmitted to the L1 caches.

Abstract: A method, apparatus, and computer implemented instructions for generating antialiased lines for display in a data processing system. Graphics data is received for display, wherein the graphics data includes primitives defining lines. A gamma correction is applied to the graphics data on a per primitive basis to form antialiased lines. The antialiased lines are displayed.

Abstract: Primitives are divided into span groups of 2N spans, and then processed in M×N blocks of pixels, with the pixel blocks preferably being as close to square as possible and therefore optimized for small spans and texture mapping. Each span group is rendered block-by-block in a serpentine manner from an initial or entry block, first in a direction away from the long edge of the primitive and then in a direction towards the long edge. The interpolators include a one-deep stack onto which pixel and texel information for the initial or entry block are pushed before rendering any other blocks within the span group. Blocks or pairs of blocks within different span subgroups of the span group are then alternately rendered, such that rendering zig-zags between the span subgroups as it proceeds to the end of the span group.

Abstract: A method and apparatus for moving pixel data from one area of a frame buffer to another in block fashion are provided. In one embodiment of the invention, pixel data is decomposed into its RGB component and each RGB component is stored into the frame buffer in a particular memory bank. The pixel data is moved by moving all the components of the data stored in a memory bank before moving the components in other memory banks.

Abstract: Graphics information is efficiently transferred from a host computer to a graphics subsystem in which rendering and pixel data is generated by the host system. A masked span operation provides an assist for 3D rendering performed by the system processor of the host and other system resources. Storage of depth, alpha, stencil, and other pixel data is in system memory including one or more ancillary graphics buffers. The main processor of the host system generates pixel data associated with an image. This data is checked against the buffers. As a result of such checking, a mask is generated by the host system. The mask is transferred in burst mode across the host-graphic subsystem PCI bus to the graphics subsystem in combination with span width, and in the case of interpolated color, color base and color increment data, and X,Y coordinate of the first pixel. In the graphics subsystem the mask is employed with the other data to load the frame buffer with the portion of pixel data defined by the mask.