Abstract: Embodiments of the present invention provide a memory arbiter for directing chipset and graphics traffic to system memory. Page consistency and priorities are used to optimize memory bandwidth utilization and guarantee latency to isochronous display requests. The arbiter also contains a mechanism to prevent CPU requests from starving lower priority requests. The memory arbiter thus provides a simple, easy to validate architecture that prevents the CPU from unfairly starving low priority agent and takes advantage of grace periods and memory page detection to optimize arbitration switches, thus increasing memory bandwidth utilization.

Abstract: The present invention optimizes graphics performance during zone rendering by providing an automatic management of bin memory between the binning and rendering phases. Embodiments of the present invention provide a mechanism by which the binner and renderer automatically share a pool of physical memory pages in order to build bin buffers and recycle them after they have been used in rendering. This is performed in such a fashion that multiple binned scenes can be queued up concurrently, with no requirement for software intervention except under exceptional conditions. The need for software management of zone rendering bin buffer memory is thus eliminated. Multiple scenes for binning and rendering can also be queued without software intervention.

Abstract: Embodiments of the present invention provide a memory arbiter for directing chipset and graphics traffic to system memory. Page consistency and priorities are used to optimize memory bandwidth utilization and guarantee latency to isochronous display requests. The arbiter also contains a mechanism to prevent CPU requests from starving lower priority requests. The memory arbiter thus provides a simple, easy to validate architecture that prevents the CPU from unfairly starving low priority agent and takes advantage of grace periods and memory page detection to optimize arbitration switches, thus increasing memory bandwidth utilization.

Abstract: A system and method for controlling peripheral devices wherein at least one command is written to a location in a system memory and a write pointer is advanced. A peripheral device then reads the at least one command from that location in memory, increments a read pointer and executes the at least one command.

Abstract: A method and apparatus for efficient translation lookaside buffer (“TLB”) management of three-dimensional surfaces is disclosed. A three-dimensional surface is represented as a square pixel surface. The square-surface representation is stored in a single entry of the TLB.

Abstract: A method, apparatus, and system to concurrently render independent images for display on one or more display devices. In an embodiment, a graphics-rendering engine concurrently renders independent images for display on multiple display devices. A time allocator arbitrates the concurrent use of the graphics-rendering engine between each independent image being rendered.

Abstract: A method, apparatus, and system to concurrently render independent images for display on one or more display devices. In an embodiment, a graphics-rendering engine concurrently renders independent images for display on multiple display devices. A graphics context manager stores in a first memory area and restores from the first memory area information describing a first rendering context associated with a first independent image. The graphics context manager stores in a second memory area and restores from the second memory area information describing a second rendering context associated with a second independent image.

Abstract: An apparatus for loading texture data into a tiled memory includes state machine logic to generate a sequence of addresses for writing a cacheline of texture data into the tiled memory according to Y-major tiling. The cacheline comprises quadwords (QWs) 0-3, wherein the sequence corresponds to an ordering of the QWs 0-3, ordered as either: (a) QW0, QW1, QW2, QW3; (b) QW1, QW0, QW3, QW2; (c) QW2, QW3, QW0, QW1; or (d) QW3, QW2, QW1, QW0, depending upon a starting address.

Abstract: An embodiment of a system logic device for improving memory bandwidth utilization in a computer system with an isochronous data stream includes a FIFO for the isochronous data stream. The FIFO includes two watermarks. When the data level of the FIFO falls below a first watermark level, a low priority request is issued to a memory controller. If the data level of the FIFO falls below a second watermark level, a high priority memory request is issued to the memory controller. The low priority memory request is assigned the lowest priority level by the memory controller. The high priority request is assigned the highest priority level by the memory controller. The low priority request allows the isochronous data stream to retrieve small amounts of data from memory without negatively impacting overall system performance while the high priority request allows the isochronous data stream to retrieve larger amounts of data from memory within a fixed time in order to ensure that the FIFO never completely drains.

Abstract: A method and apparatus for implementing a dynamic display memory is provided. A memory control hub suitable for interposition between a central processor and a memory includes a graphics memory control component. The graphics memory control component determines whether operands accessed by the central processor are graphics operands. If so, the graphics memory control component transforms the virtual address supplied by the central processor to a system address suitable for use in locating the graphics operand in the memory. In one embodiment, the graphics control component maintains a graphics translation table in the memory and utilizes the graphics translation table in transforming virtual addresses to system addresses. Furthermore, in one embodiment, the graphics control component reorders the addresses of the graphics operands to optimize for performance memory accesses by a graphics device.

Abstract: A method and apparatus for implementing a dynamic display memory is provided. A memory control hub suitable for interposition between a central processor and a memory includes a graphics memory control component. The graphics memory control component determines whether operands accessed by the central processor are graphics operands. If so, the graphics memory control component transforms the virtual address supplied by the central processor to a system address suitable for use in locating the graphics operand in the memory. In one embodiment, the graphics control component maintains a graphics translation table in the memory and utilizes the graphics translation table in transforming virtual addresses to system addresses. Furthermore, in one embodiment, the graphics control component reorders the addresses of the graphics operands to optimize for performance memory accesses by a graphics device.

Abstract: According to one embodiment, a computer system is disclosed that includes a memory and a memory controller coupled to the memory. The memory controller includes an arbitration unit that may be programmed to operate according to a first arbitration mode or a second arbitration mode. The computer system also includes a first device and a second device coupled to the arbitration unit. According to a further embodiment, the first device is assigned a higher priority classification than the second device for accessing the memory while the arbitration unit is operating according to the first arbitration mode. In addition, the first device and the second device are assigned equal priority classifications for accessing the memory while the arbitration unit is operating according to the second arbitration mode.

Abstract: A method for controlling processing of overlay requests is disclosed. The method comprises the step of disabling an overlay request to a memory. The overlay request to system memory has expedited processing priority over requests to a system memory by other devices. The overlay request is disabled for a predetermined time period and enabled after the predetermined time period has elapsed.

Abstract: An apparatus for an efficient display flip is disclosed. The apparatus has a computer readable medium having a graphics driver. The execution of the graphics driver is configured to generate instructions for checking status of a graphics device to determine whether the graphics device is ready to display a next frame data on a display device. The graphics device is coupled to a system memory. The graphics device is configured to forwarding a display flip status to the system memory for access by the graphics driver in response to the instructions.

Abstract: A method for mutual exclusion of drawing engine execution on a graphics device is disclosed. The method checks a busy signal of an executing drawing engine. The executing drawing engine is one of a plurality of drawing engines of the graphics device and the only drawing engine executing out of the plurality of drawing engines. The method forwards a graphics instruction and associated data packet to a next drawing engine to execute after the executing drawing engine has completed execution. The next drawing engine to execute is one of the plurality of drawing engines.

Abstract: A pipeline apparatus for processing 3D graphics data will be described. The pipeline apparatus includes a first request memory to fetch information corresponding to a texture operand. A second request memory fetches information responding to a color operand and Z operand. A control circuit coordinates data flow from the first request memory and the second request memory into a memory channel by preventing the number of requests from the first request memory from exceeding by a predetermined number, the number of requests from the second request memory. By properly coordinating the data flow, deadlock of a data fetching pipeline is avoided.

Abstract: A method for communicating graphics device status information to a graphics driver. Status of a graphics device is checked to determine whether the graphics device is ready to process a next instruction. A location in cacheable memory accessible to a graphics driver is updated with the status. The graphics driver reads the status to determine when to generate the next instruction for processing by the graphics data. A first instruction to be forwarded to the graphics device is generated. A status in an operating register in the graphics device is updated indicating that an event is being monitored. The updating is performed in response to receipt of the first instruction by the graphics device. The status is written to a second cacheable location in system memory accessible to the graphics driver. A second instruction is generated by the graphics driver to provide a predetermined address and instruction completion data to the graphics device.

Abstract: In one aspect of the present invention, a method is provided for controlling dispatches of requested data packets. The method includes sending information on each of the requested data packets to a request buffer, generating at least one size signal from the information sent on each of the requested data packets, and generating an available space signal. The size signal corresponds to a size of one of the requested data packets that may be received next. The available space signal corresponds to space available in a data buffer. The data buffer receives the requested data packets. The method also includes comparing the size signal to the available space signal and asserting a data buffer full signal in response to the size signal being greater than the available space signal.

Abstract: A method and apparatus for regulating the deferral of a transaction issued on a bus by a processor in a computer system is disclosed. A bus transaction recorder coupled to the bus processes encoded signals from the transaction issued on the bus. A line coupled to the bus sends an indication signal when a pending transaction request is issued on the bus. A CPU latency timer times the current transaction on the bus when a new pending transaction is waiting on the bus. The CPU latency timer outputs an expiration signal when the transaction takes more than a predetermined amount of time to complete. A transaction processor unit is coupled to the bus transaction recorder, the line, and the CPU latency timer.

Abstract: A data storage array is provided having a number, n, of sequential data storage areas for the storage of data. A valid status array including n bits is provided where there is a one to one correspondence between the bits of the valid status array and the data storage areas of the data storage array. When valid data are written into a data storage area, the status bit of the valid status array corresponding to this data storage area is set to indicate that valid data are present. When data are read out of the data storage area, the corresponding status bit is cleared indicating the absence of valid data. If the data storage array is one that is written to in a random access manner and read from sequentially, as a queue, then the valid status array would indicate the presence of valid data at the head of the queue for the data storage array.