Abstract: Embodiments of the present invention provide end-to-end frame time synchronization designed to improve smoothness for displaying images of 3D applications, such as PC gaming applications. Traditionally, an application that renders 3D graphics functions based on the assumption that the average render time will be used as the animation time for a given frame. When this condition is not met, and the render time for a frame does not match the average render time of prior frames, the frames are not captured or displayed at a consistent rate. This invention enables feedback to be provided to the rendering application for adjusting the animation times used to produce new frames, and a post-render queue is used to store completed frames for mitigating stutter and hitches. Flip control is used to sync the display of a rendered frame with the animation time used to generate the frame, thereby producing a smooth, consistent image.

Abstract: Embodiments of the present invention provide end-to-end frame time synchronization designed to improve smoothness for displaying images of 3D applications, such as PC gaming applications. Traditionally, an application that renders 3D graphics functions based on the assumption that the average render time will be used as the animation time for a given frame. When this condition is not met, and the render time for a frame does not match the average render time of prior frames, the frames are not captured or displayed at a consistent rate. This invention enables feedback to be provided to the rendering application for adjusting the animation times used to produce new frames, and a post-render queue is used to store completed frames for mitigating stutter and hitches. Flip control is used to sync the display of a rendered frame with the animation time used to generate the frame, thereby producing a smooth, consistent image.

Abstract: Embodiments of the present invention provide end-to-end frame time synchronization designed to improve smoothness for displaying images of 3D applications, such as PC gaming applications. Traditionally, an application that renders 3D graphics functions based on the assumption that the average render time will be used as the animation time for a given frame. When this condition is not met, and the render time for a frame does not match the average render time of prior frames, the frames are not captured or displayed at a consistent rate. This invention enables feedback to be provided to the rendering application for adjusting the animation times used to produce new frames, and a post-render queue is used to store completed frames for mitigating stutter and hitches. Flip control is used to sync the display of a rendered frame with the animation time used to generate the frame, thereby producing a smooth, consistent image.

Abstract: Embodiments of the present invention provide end-to-end frame time synchronization designed to improve smoothness for displaying images of 3D applications, such as PC gaming applications. Traditionally, an application that renders 3D graphics functions based on the assumption that the average render time will be used as the animation time for a given frame. When this condition is not met, and the render time for a frame does not match the average render time of prior frames, the frames are not captured or displayed at a consistent rate. This invention enables feedback to be provided to the rendering application for adjusting the animation times used to produce new frames, and a post-render queue is used to store completed frames for mitigating stutter and hitches. Flip control is used to sync the display of a rendered frame with the animation time used to generate the frame, thereby producing a smooth, consistent image.

Abstract: Embodiments of the present invention provide end-to-end frame time synchronization designed to improve smoothness for displaying images of 3D applications, such as PC gaming applications. Traditionally, an application that renders 3D graphics functions based on the assumption that the average render time will be used as the animation time for a given frame. When this condition is not met, and the render time for a frame does not match the average render time of prior frames, the frames are not captured or displayed at a consistent rate. This invention enables feedback to be provided to the rendering application for adjusting the animation times used to produce new frames, and a post-render queue is used to store completed frames for mitigating stutter and hitches. Flip control is used to sync the display of a rendered frame with the animation time used to generate the frame, thereby producing a smooth, consistent image.

Abstract: A multiprocessor switching device substantially implemented on a single CMOS integrated circuit is described in connection with a parallel routing scheme for calculating routing information for incoming packets. Using the programmable hash and route routing scheme, a hash and route circuit can be programmed for a variety of applications, such as routing, flow-splitting or load balancing.

Abstract: A multiprocessor switching device substantially implemented on a single CMOS integrated circuit is described in connection with a parallel routing scheme for calculating routing information for incoming packets. Using the programmable hash and route routing scheme, a hash and route circuit can be programmed for a variety of applications, such as routing, flow-splitting or load balancing.

Abstract: Where a null response can be expected from devices snooping a load operation, data may be used by a requesting processor prior to the coherency response window. A null snoop response may be determined, for example, from the availability of the data without a bus transaction. The capability of accelerating data in this fashion requires only a few simple changes in processor state transitions, required to permit entry of the data completion wait state prior to the response wait state. Processors may forward accelerated data to execution units with the expectation that a null snoop response will be received during the coherency response window. If a non-null snoop response is received, an error condition is asserted. Data acceleration of the type described allows critical data to get back to the processor without waiting for the coherency response window.

Abstract: A system and method are provided for maintaining cache coherency in symmetric multiprocessor system by having logic for performing snoop queries separate from logic for performing snoop actions. This logic split permits increased throughput because pending snoop queries must no longer wait until snoop actions complete. Two state machines are disclosed: a pipeline state machine for snoop queries; and a snoop action state machine, for executing the split logic handling snoop requests.

Abstract: A method and system of facilitating storage accesses within a multiprocessor system subsequent to a synchronization instruction by a local processor consists of determining if data for the storage accesses is cacheable and if there is a “hit” in a cache. If both conditions are met, the storage accesses return the data to the local processor. The storage accesses have an entry on an interrupt table which is used to discard the returned data if a snoop kills the line before the synchronization instruction completes. After the cache returns data, a return data bit is set in the interrupt table. A snoop killing the line sets a snooped bit in the interrupt table. Upon completion of the synchronization instruction, any entries in the interrupt table subsequent to the synchronization instruction that have the return data bit and snooped bit set are flushed.

Abstract: A multiprocessor computer system including a set of processors where each processor in the set includes an execution unit for issuing operations and a processor queue suitable for queuing previously issued and still pending operations. The multiprocessor further includes means for forwarding operations issued by the processor to the processor queue and to an operation block queue of a memory subsystem that is connected to the multiprocessor. The depth of (i.e., the number of entries in) the operation block queue matches the depth of the processor queue. The processor queue, when full, inhibits the processor from issuing additional operations. In this manner, an operation issued by the processor is guaranteed an available entry in the operation block queue of the memory subsystem thereby eliminating the need for operation retry circuitry and protocols such as handshaking.

Abstract: A multi processor computer system including a set of processors connected to a memory subsystem via a local interconnect. The memory subsystem includes a load miss block suitable for queuing a first processor load operation that misses in an L1 cache of the first processor and a store miss block suitable for queuing store type operations. The subsystem further includes an arbiter suitable for receiving queued operations from the load and store miss blocks. The arbiter is further configured for selecting one of the received operations and initiating the selected operation. The subsystem further includes means for snooping the address associated with the first processor load operation when the first processor load operation is selected and initiated by the arbiter. The subsystem further includes a snoop control block adapted to receive a snoop response from a second processor associated with the memory subsystem.

Abstract: A method and system for performing write-through store operations of valid data of varying sizes in a data processing system, where the data processing system includes multiple processors that are coupled to an interconnect through a memory hierarchy, where the memory hierarchy includes multiple levels of cache, where at least one lower level of cache of the multiple of levels of cache requires store operations of all valid data of at least a predetermined size. First, it is determined whether or not a write-through store operation is a cache hit in a higher level of cache of the multiple levels of cache. In response to a determination that cache hit has occurred in the higher level of cache, the write-through store operation is merged with data read from the higher level of cache to provide a merged write-through operation of all valid data of at least the predetermined size to a lower level of cache.

Abstract: The present invention provides a method and apparatus for allowing autonomous, way specific tag updates. More specifically, the invention provides way specific tag and status updates while concurrently allowing reads of the ways not currently being updated. If a read hit is determined, then the read is processed in a typical fashion. However, if the read is a read miss and one of the ways is flagged as being updated, then all ways are read again once the specific way has completed its updated.

Abstract: A multiprocessor computer system including a set of processors connected to a memory subsystem via a local interconnect. The memory subsystem includes a load miss block suitable for queuing a first processor load operation that misses in an L1 cache of the first processor and a store miss block suitable for queuing store type operations. The subsystem further includes an arbiter suitable for receiving queued operations from the load and store miss blocks. The arbiter is further configured for selecting one of the received operations and initiating the selected operation. The subsystem further includes means for snooping the address associated with the first processor load operation when the first processor load operation is selected and initiated by the arbiter. The subsystem further includes a snoop control block adapted to receive a snoop response from a second processor associated with the memory subsystem.

Abstract: Data loaded from system memory to a cache within a multiprocessor system is set to the exclusive coherency state if no other cache or processor has a copy of that data. Subsequent accesses to the data by another processor or cache which are snooped by the data owner result in an exclusive intervention by the data owner. The data owner sources the data to and shares the data with the requesting device on a read and transfers exclusive ownership of the data to the requesting device on a read with intent to modify. Unmodified intervention with cache-to-cache transfers over possibly much slower accesses to memory is thus supported by the multiprocessor system without requiring additional tag or status bits in the cache directories, saving a significant area.

Abstract: A queuing apparatus associated with a processor includes at least one static queue (11), an index generator (34), at least one index queue (37), and a static queue accessing arrangement. Each static queue (11) has a number of static queue locations (12), each for storing a static queue entry and an availability indicator (14) for indicating an availability status of the respective static queue location. The index generator (34) uses information from the static queue (11) to provide a unique index value for each static queue entry, the index value for a particular static queue entry identifying the static queue location (12) containing the particular static queue entry. Each index queue (37, 42) has a number of index queue locations (40), each for storing one of the index values provided by the index generator (34).

Abstract: A multiprocessor computer system including a multiprocessor device preferably comprised of a set of processors, each including a respective L1 cache. The multiprocessor is preferably fabricated as a single device. The computer system includes a memory subsystem comprised of a load miss block adapted for queuing a load operation issued by a first processor that misses in an L1 cache of the first processor and a store miss block adapted for queuing store type operations. An arbiter of the memory subsystem is configured to receive queued operations from the load and store miss blocks and further configured to select and initiate one of the received operations. The subsystem further includes means for forwarding the address associated with the load miss operation to a lower level cache and means for receiving a hit/miss response from the lower level cache.

Abstract: Where a plurality of ordered transactions are received for data transfers on a pipelined bus, each transaction in the series is initiated before all prospective retry responses to the preceding ordered transactions may be asserted. The address responses to all preceding ordered transfers are then monitored in connection with performance of the newly initiated transfer. If a retry response to any preceding ordered transaction is asserted, a self-initiated retry response for all subsequent transactions, including the newly initiated transfer, is also asserted. The system-retried transactions and all succeeding, ordered transactions are immediately reattempted. The overlapping performance of the ordered transfers reduces the latency of non-retried transfers, achieving performance comparable to non-ordered transactions.

Abstract: The present invention provides a method and apparatus for optimizing bus utilization while maintaining read and write coherence. More specifically the invention provides bus utilization optimization by prioritizing read transactions before write transactions, where there is no collision pending. When a collision pending is determined, then the read and write transactions are processed according to the age of the transaction(s) allowing for data coherency.