Abstract: A media player and a method for operating a media player are disclosed. A media program is able to substantially immediately begin playing after a media play selection has been made. Through intelligent operation, the media program is able to start playing even before the media program has been substantially or completely loaded from disk storage into semiconductor memory (i.e., cache memory). Additionally, the media program can be loaded into semiconductor memory through use of a background process without disturbing the playing of the media program. Further, if desired, the disk storage is able to be aggressively “powered off” when not being accessed, thereby enhancing battery life when being battery-powered.

Abstract: A cache is provided which has low power dissipation. An execution engine generates a sequential fetch signal indicating that data required at a next cycle is stored at a next location of just previously used data. A line reuse buffer is provided which stores data that is stored in a data memory of the cache and is in the same cache line as data just previously used by the execution engine. In the case where the sequential fetch signal is received and data required according to a memory request signal is stored in the same cache line of the data memory as the just previously used data, a cache controller fetches data from the line reuse buffer and controls the cache so as to stay in a stand-by mode.

Abstract: A congestion control and avoidance method including a method check step of determining whether the request contents is cacheable or uncacheable on the basis of the request inputted from the client terminal, a first Uniform Resource Identifier (URI) check step of, when it is determined that the request contents is cacheable in the method check step, checking a URI included in the request from the client terminal to determine whether the request contents is cacheable or uncacheable, a first URI hash search step of, when it is determined that the request contents is cacheable based on determination of the first URI check step, searching a URI hash to determine to execute any of regular caching, priority caching and access limitationing operation, and a step of executing any of the regular caching, priority caching and access limitationing operation according to determination in the first URI hash search step.

Abstract: Embodiments of the present invention include a memory controller that provides memory line caching and memory transaction coherency by using at least one memory controller agent. The memory controller includes at least one memory-controller agent, an incoming memory-transaction dispatch unit, and an outgoing memory-transaction completion unit. Each memory-controller agent has a memory-line memory controller and a memory-line coherency controller, along with a cache memory capable of caching the contents of a memory line along with coherency information for the memory line. Memory transactions are received from cacheable entities of a computer system at the incoming memory-transaction dispatch unit, and are then presented to one or more agents. If multiple memory-read transactions are received for a single memory line, the agents will configure themselves into a linked list to queue up the requests.

Abstract: Method and apparatus for conditioning program control flow on the presence of requested data in a cache memory. In a data processing system that includes a cache memory and a system memory coupled to a processor, in various embodiments program control flow is conditionally changed based on whether the data referenced in an instruction are present in the cache memory. When an instruction that includes a data reference and an alternate control path is executed, the control flow of the program is changed in accordance with the alternate control path if the referenced data are not present in the cache memory. The alternate control path is either explicitly specified or implicit in the instruction.

Abstract: A method and system directed to reducing the bottleneck to storage. In one aspect of the invention, a data-aware data flow manager is inserted between storage and a process or device requesting access to the storage. The data-aware data flow manager determines which data to cache and which data to pipe directly through. Through intelligent management and caching of data flow, the data-aware data flow manager is able to avoiding some of the latencies associated with caches that front storage devices. The data-aware data flow manager may determine whether to cache data or pipe it directly through based on many factors including type of data requested, state of cache, and user or system policies.

Abstract: In a computer architecture using a prevalidated tag cache design, logic circuits are added to enable store and invalidation operations without impacting integer load data access times and to invalidate stale cache lines. The logic circuits include a translation lookaside buffer (TLB) architecture to handle store operations in parallel with a smaller, faster integer load TLB architecture. A store valid module, added to the TLB architecture, sets a valid bit when a new cache line is written. The valid bit is cleared on the occurrence of an invalidation operation. The valid bit prevents multiple store updates or invalidates for cache lines that are already invalid.

Abstract: A shared bypass bus structure for low-latency coherency controller access in a coherent scalable switch. In a coherent scalable switch with multiple coherent interconnect ports, distributed coherency control structures, and a crossbar interface between them, a shared bypass bus permits data transfer between the coherent interconnect ports and the coherency control structures while bypassing the crossbar interface. Some embodiments may comprise scalable switches to support one or more sets of processors with substantially independent snoop or cache coherency paths or arrangements.

Abstract: Data movement within a computing environment is at the very least reduced. Data is transmitted between a file system of the computing environment and a transmission medium of that environment. The transmission includes bypassing non-file system buffers in performing the transmission. For example, when data is sent to the file system to be written to one or more storage media, the file system swaps one or more buffers of the file system with the one or more buffers containing the data. The swapping does not require the copying of data. Further, for a read operation, the file system calls a routine, which is provided with one or more pointers to the data that is to be sent to a requester of the data.

Abstract: Techniques for thread-based register file access by a multithreaded processor are disclosed. The multithreaded processor determines a thread identifier associated with a particular processor thread, and utilizes at least a portion of the thread identifier to select a particular portion of an associated register file to be accessed by the corresponding processor thread. In an illustrative embodiment, the register file is divided into even and odd portions, with a least significant bit or other portion of the thread identifier being used to select either the even or the odd portion for use by a given processor thread. The thread-based register file selection may be utilized in conjunction with token triggered threading and instruction pipelining. Advantageously, the invention reduces register file port requirements and thus processor power consumption, while maintaining desired levels of concurrency.

Abstract: A hierarchically organized, compilable semiconductor memory circuit having multiple levels with simultaneous access and cache loading. A first level memory portion and at least a next level memory portion are provided as part of the semiconductor memory circuit, wherein the memory portions are associated with separate Data In (DIN) and Data Out (DOUT) buffer blocks for effectuating data operations. DIN buffer blocks of the first level and intermediate levels, if any, are provided with multiplexing circuitry that is selectively actuatable for providing data accessed in the next level memory portion to Local Data In (LDIN) driver circuitry, whereby the accessed data is simultaneously loaded into the first and intermediate levels. Accordingly, extra clock cycles are saved from cache loading of the data used for subsequent memory operations.

Abstract: A virtual sequential data storage (VSDS) system includes a VSDS controller coupled to physical data storage and a host machine with at least one host application. The controller is configured to carry out commands from the host application referencing VSDS. A router installed at the host intercepts prescribed types of host application commands directed to the controller. For each intercepted read/write command, the router determines a target physical location in physical data storage to carry out the intercepted host read/write command. Also, if the host application command is a read command, the router transfers data requested by the read command from the target physical location to the host application bypassing the controller. If the host application command is a write command, the router transfers write data associated with the write command from the host application to the target physical location bypassing the controller.

Abstract: In a multiprocessor data processing system including: a main memory; at least first and second shared caches; a system bus coupling the main memory and the first and second shared caches; at least four processors having respective private caches with the first and second private caches being coupled to the first shared cache and to one another via a first internal bus, and the third and fourth private caches being coupled to the second shared cache and to one another via a second internal bus; method and apparatus for preventing hogging of ownership of a gateword stored in the main memory and which governs access to common code/data shared by processes running in at least three of the processors. Each processor includes a gate control flag. A gateword CLOSE command, establishes ownership of the gateword in one processor and prevents other processors from accessing the code/data guarded until the one processor has completed its use.

Abstract: A system and method for storing data, the system having one or more storage devices, caches data from a sender into a first random-access structure located in a first cache level, caches data from the first cache level into a log structure located in a second cache level, and stores data from CL into a second random-access structure located in a storage level, wherein CL is the first cache level or the second cache level. In further embodiments of the invention, the second cache level caches in the log structure parity data for the data cached in the log structure. In a still further embodiment of the invention, the storage level stores in the second random-access structure parity data for the data stored in the second random-access structure.

Abstract: There is disclosed a data processor for stalling the instruction execution pipeline after a cache miss and re-loading the correct cache data into any bypass devices before restarting the pipeline.

Abstract: A cache management system includes a main memory for storing instructions and information for identifying cache control instructions, a central processing unit (CPU) for executing the instructions, an instruction identifier for identifying that an instruction stored the main memory is a cache control instruction, a cache controller for predicting a next instruction to be executed by the CPU and for reading a corresponding program information in advance when the cache control instruction is identified by the instruction identifier, and a cache memory for storing executable instructions and data from the main memory and for supplying the executable instructions to the CPU under the control of the cache controller.

Abstract: Layer 7 switching may be accomplished using one or more caches placed throughout a computer network. Changes to a file on a server may be detected and propagated throughout the network. At the switch or router level, once notification of changes to a file is received, the content may be retrieved from the server and placed in a connected cache. A routing table entry may be created for the content and also placed in the cache. The routing table entry may contain an original location field identifying the original location of the content, a distance field indicating a distance from the cache to the server, and a field indicating a version number of the content. Additional fields may also be contained within the routing table entry. When a user requests a specific file, rather than forward the request directly to the server containing the original file, the request may be handled by the router closest to the user which has a connected cache containing the content.

Abstract: A multi-processor includes multiple processing clusters for performing assigned applications. Each cluster includes a set of compute engines, with each compute engine coupled to a set of cache memory. A compute engine includes a central processing unit and a coprocessor with a set of application engines. The central processing unit and coprocessor are coupled to the compute engine's associated cache memory. The sets of cache memory within a cluster are also coupled to one another.

Abstract: Embodiments are provided in which cache updating is described for a computer system having at least a first processor and a second processor having a first cache and a second cache, respectively. When the second processor obtains from the first processor a lock to a shared memory region, the first cache pushes to the second cache cache lines for the addresses in the shared memory region accessed by the first processor while the first processor had the lock.

Abstract: A system and method are provided for using cache memory when reading data from system memory particularly when the primary memory could include memory types other than fast read-write memory. Also, a system and method are provided for using cache memory when writing data to system memory particularly when the primary memory could include memory types other than fast read-write memory.

Abstract: The present invention provides an instruction cache apparatus and method using the instruction read buffer. The apparatus comprises an instruction hit analysis unit, an instruction read buffer, a first cache instruction word memory, a second cache instruction word memory, a first multiplexer and a second multiplexer. The instruction hit analysis unit receives a programmable counter output signal, compares this with a plurality of tags, and after the analysis, outputs the instruction hit signal of the instruction read buffer and the instruction hit signal of the first cache instruction word memory. The second multiplexer reads the expected instruction word from one of either the first cache instruction word memory, the second cache instruction word memory or the first multiplexer according to the instruction hit signal of the instruction read buffer and the instruction hit signal of the first cache instruction word memory.

Abstract: A system and method are provided for moving information between cache coherent memory systems of a partitioned multiprocessor computer system while containing faults to a single partition. The multiprocessor computer system includes a plurality of processors, memory subsystems and input/output (I/O) subsystems that can be divided into a plurality of partitions. Each I/O subsystem includes at least one I/O bridge for interfacing between one or more I/O devices and the multiprocessor system. The I/O bridge has a data mover configured to retrieve information from a “source” partition and to store that information within its own “destination” partition. When activated, the data mover issues a request to the source partition for a non-coherent copy of the information. The home memory subsystem in the source partition preferably responds to the request by sending the data mover “valid”, but non-coherent copy of the information, e.g.

Abstract: A system and method is provided for user and command specific place based caching with cache validation, including a server; a database; a server cache; the server responsive to receiving a request message for generating a user-specific cache file name, accessing the server based cache with the file name to obtain a cached response message, validating the cached response message, generating a response message selectively from the cached response message if obtained and validated, and otherwise generating from the database and selectively caching the response message.

Abstract: A method of operating a circuit is disclosed. The method generally comprises the steps of (A) generating a particular policy of a plurality of policies by a lookup operation on a first transaction request received by the circuit, (B) generating a second transaction request for use by a memory external to the circuit based upon the first transaction request and the particular policy in response to a first cache signal of the first transaction request having a non-cacheable state and (C) searching a plurality of address tags for cache data cached within the circuit for a match with the first transaction request in response to the first cache signal having a cacheable state.

Abstract: A technique for reducing the latency associated with a memory read request. A bypass path is provided to direct the address of a corresponding request to a memory controller. The memory controller initiates a speculative read request to the corresponding address location. In the meantime, the original request is decoded and directed to the targeted area of the system. If the request is a read request, the memory controller will receive the request, and after comparing the request address to the address received via the bypass path, the memory controller will cancel the request since the speculative read has already been issued. If the request is directed elsewhere or is not a read request, the speculative read request is cancelled.

Abstract: Cache allocation includes a cache memory and a cache management mechanism configured to allow an external agent to request data be placed into the cache memory and to allow a processor to cause data to be pulled into the cache memory.

Abstract: A memory controller retrieves data from memory before such data has actually been requested by an electrical device. The RAM controller may store such data into a prefetch buffer.

Abstract: The present invention provides a technique of controlling cache operation on a node device in a computer system that enables transmission and receipt of data between clients and a storage device via the node device. In accordance with a first control method, the data stored in the storage device includes attribute data, as to whether or not the data is cacheable. This application enables the node device to relay non-cacheable data without process of the cache. In accordance with a second control method, the node device encrypts the data when caching the data in the disk. In accordance with a third control method, non-cacheable data is transmitted and received directly without going through the node device. These applications enable the cache in the node device to be restricted, and thereby ensure security.

Abstract: In a computer architecture using a prevalidated tag cache design, logic circuits are added to enable store and invalidation operations without impacting integer load data access times and to invalidate stale cache lines. The logic circuits may include a translation lookaside buffer (TLB) architecture to handle store operations in parallel with a smaller, faster integer load TLB architecture. A store valid module is added to the TLB architecture. The store valid module sets a valid bit when a new cache line is written. The valid bit is cleared on the occurrence of an invalidation operation. The valid bit prevents multiple store updates or invalidates for cache lines that are already invalid. In addition, an invalidation will block load hits on the cache line. A control logic is added to remove stale cache lines. When a cache line fill is being processed, the control logic determines if the cache line exists in any other cache segments.

Abstract: One embodiment of the present invention provides a system that facilitates storage of objects in a persistent memory with asymmetric access characteristics. The system operates by receiving an access to an object. If the access is a read access, the system looks up the object through an indirectory. This indirectory includes an entry that points to a location of the object within the persistent memory if updates to the object have been recorded in the persistent memory. Otherwise, the indirectory entry points to a location of the object within a volatile memory. If the object is located in the volatile memory, the system reads the object from the volatile memory. Otherwise, if the object is located in the persistent memory, the system reads the object from the persistent memory directly without first copying the object into the volatile memory. In one embodiment of the present invention, if the access is a write access, the system looks up the object through the indirectory.

Abstract: A digital system and method of operation is provided in which several processors (590n) are connected to a shared cache memory resource (500). A translation lookaside buffer (TLB) (310n) is connected to receive a request virtual address from each respective processor. A set of address regions (pages) is defined within an address space of a back-up memory associated with the cache and write allocation in the cache is defined on a page basis. Each TLB has a set of entries that correspond to pages of address space and each entry provides a write allocate attribute (550) for the associated page of address space. During operation of the system, software programs are executed and memory transactions are performed. A write allocate attribute signal (550) is provided with each write transaction request. In this manner, the attribute signal is responsive to the value of the write allocation attribute bit assigned to an address region that includes the address of the write transaction request.

Abstract: A peripheral interface circuit for handling graphics responses in an I/O node of a computer system. A peripheral interface circuit includes a buffer circuit coupled to receive packet commands. The buffer circuit includes a plurality of buffers each corresponding to a respective virtual channel of a plurality of virtual channels for storing selected packet commands that belong to the respective virtual channel. The peripheral interface circuit may determine whether a given one of the received packet commands is a graphics response belonging to a particular respective virtual channel. In response to determining that the given packet command is a graphics response belonging to the particular respective virtual channel, the buffer circuit may cause the given packet command to bypass the plurality of buffers.

Abstract: Briefly, in accordance with one embodiment of the invention, a processor has a loop buffer and a cache that provides requested information to a processor core.

Abstract: A system 100 including a central processing unit 101 operates in response to a set of instructions for processing information. A port 134 provides access to selected circuitry forming a part of the system by an external device. A set of non-volatile programmable security elements 136 selectively enable and disable the operation of the interface to provide a private environment for processing the information.

Abstract: A system and method for distributed cache. Cache tag storage and cache data storage are maintained in separate pipeline stages. Cache tag storage is operated by a data producer. Cache data storage is operated by a data consumer. Cache hits and misses are determined by the data producer prior to any operations being performed by the processor. In the event of a cache miss, produced data is sent to the processor to be processed. In the event of a cache hit, the cache address of the corresponding previously processed data is sent to the data consumer so that the corresponding processed data unit can be retrieved from cache data storage.

Abstract: A method and system directed to reducing the bottleneck to storage. In one aspect of the invention, a data-aware data flow manager is inserted between storage and a process or device requesting access to the storage. The data-aware data flow manager determines which data to cache and which data to pipe directly through. Through intelligent management and caching of data flow, the data-aware data flow manager is able to avoiding some of the latencies associated with caches that front storage devices. The data-aware data flow manager may determine whether to cache data or pipe it directly through based on many factors including type of data requested, state of cache, and user or system policies.

Abstract: Machine-readable media, methods, and apparatus are described for processing coherent requests of a computing device comprising multiple cache nodes. In some embodiments, a coherent switch may receive from a requesting cache node a coherent request for a line of memory. The coherent switch may further issue snoop requests to one or more non-requesting cache nodes based upon whether a snoop filter bypass mode is enabled. In particular, the coherent switch when not in snoop filter bypass mode may obtain coherency data from a snoop filter and may issue snoop requests to zero or more non-requesting cache nodes based upon the coherency data obtained from the snoop filter. Further, the coherent switch when in snoop filter bypass mode may bypass the snoop filter and may issue snoop requests to all non-requesting cache agents.

Abstract: A method and apparatus for purging data from a middle cache level without purging the corresponding data from a lower cache level (i.e., a cache level closer to the processor using the data), and replacing the purged first data with other data of a different memory address than the purged first data, while leaving the data of the first cache line in the lower cache level. In some embodiments, in order to allow such mid-level purging, the first cache line must be in the “shared state” that allows reading of the data, but does not permit modifications to the data (i.e., modifications that would have to be written back to memory). If it is desired to modify the data, a directory facility will issue a purge to all caches of the shared-state data for that cache line, and then the processor that wants to modify the data will request an exclusive-state copy to be fetched to its lower-level cache and to all intervening levels of cache.

Abstract: Computer systems and methods that provide for cacheable above one megabyte system management random access memory (SMRAM). The systems and methods comprise a central processing unit (CPU) having a processor and a system management interrupt (SMI) dispatcher, a cache coupled to the CPU, and a chipset memory controller that interfaces the CPU to a memory. The memory includes system memory and the system management random access memory. The systems and methods un-cache the SMRAM while operating outside of system management mode, transfer CPU operation to system management mode upon execution of a system management interrupt (SMI), and change cache settings to cache the extended memory and system management random access memory with write-through. The systems and methods then change cache settings to cache the extended memory with write-back and un-cache the SMRAM upon execution of an resume instruction.

Abstract: A method and system are shown for bypassing memory controller components when processing memory requests. A memory controller analyzes internal components to determine if any pending memory requests exist. If particular memory controller components are idle, a memory client is informed that a bypassing of memory controller components is possible. A bypass module of the memory controller receives memory requests from the memory client. The bypass module examines memory controller parameters and a configuration of main memory to determine which memory controller components may be bypassed and routes the memory request accordingly. In a system with asynchronous memory, the memory controller provides copies of the memory request through a dual pipeline. A first copy of the memory request is processed through a bypass module to attempt to bypass memory controller components. A second copy of the memory request is processed in a normal fashion in case a bypass of the memory access request is not possible.

Abstract: A source cache transfers data to an intermediate cache along a data connection. The intermediate cache is provided between the source cache and a target, and includes a memory array. The source cache may also transfer data to the target along the data connection while bypassing the memory array of the intermediate cache.

Abstract: The present invention relates to a system and method to efficiently move data from one data bus to another data bus in a network switch. The method includes generating a packet cycle on a first data bus. The method also includes generating a control data cycle on a second data bus. The method further includes processing the packet cycle on the first data bus after processing the control data cycle on the second data bus.

Abstract: A method of optimizing speculative address load processing by a microprocessor includes identifying a speculative load, marking the speculative load, determining whether a miss occurs for the speculative load, and preventing use of the marked speculative load by the microprocessor if a miss occurs. A method of optimizing speculative address load processing by a microprocessor includes identifying a speculative load, marking the speculative load, inserting the marked speculative load into a load miss queue, determining whether a miss occurs for the speculative load, and preventing the load miss queue from committing the marked speculative load to cache if a miss occurs.

Abstract: A memory architecture is disclosed. A memory device may comprise at least two memory blocks electrically coupled in a pipelined manner. Each block may comprise a memory array, and a bypass network. A system may include several memory blocks coupled together in a pipelined manner electrically coupled to at least two functional units.

Abstract: A computer system includes a processor, a cache, a system bus, a memory-control subsystem, an external memory bus, RAM memory, and flash memory. All but the last three are fabricated on a single ASIC. The memory control subsystem includes a RAM controller, a flash-memory controller, and a memory interface between the controllers and the memories. In addition, the memory-control subsystem includes a system-bus FIFO write buffer. During an external-memory access, the request information is transferred from the system bus to the system-bus buffer instead of directly to the memory interface. The system-bus buffer stores address data, content data (in the case of a write request), and control data. In turn, the control data is forwarded to the appropriate controller and the address data and the content data are forwarded to external memory bus. Note that only one system-bus write buffer is required despite the plural memory controllers.

Abstract: This invention provides a dual usage cache reload buffer (CRB) to hold both demand loads as well as prefetch loads. A new form of a data cache block touch (DCBT) instruction specifies which level of the cache hierarchy to prefetch data into. A first asynchronous form of a DCBT instruction is issued to prefetch a stream of data into a L2 cache. A second synchronous form of a DCBT instruction is used to prefetch data from the L2 cache to the CRB in the main CPU, which will bypass the L1 data cache and forward data directly to the register file. This CRB has a dual usage and is used to hold both normal cache reloads as well as the aforementioned prefetched cache lines.

Abstract: Methods and systems for handling requests received from a client for information stored on a server. In general, when a request for information is received, cache functions are bypassed or executed based on whether an execution of cache functions in an attempt to access the information from cache is likely to slow processing of a request for the information without at least some compensating reduction in processing time for a request for the information received at a later time. Also described is receiving information that identifies the location of a resource within a domain and selecting a cache based on the information that identifies the location of the resource within the domain.

Abstract: Cache defining arrangements for maximizing cacheable memory space, including a mixed technique scheme using a bottom-up scheme defining a first non-memory-hole portion using mainly substantially additive blocks of cacheable space, and a top-down scheme defining a second non-memory-hole portion by defining an oversized block of cacheable space and using mainly substantially subtractive blocks of cacheable space.

Abstract: In an information processing system having a data processing apparatus, a control unit for a cache memory, and a storage unit for storing a record, respectively interconnected together, wherein when the control unit receives from the data processing apparatus a write request for a record to be written and if the record to be written is not being stored in the cache memory, the control unit receives a data to be written in the object record from the data processing apparatus and stores the received data in the cache memory. After notifying the data processing apparatus of a completion of a data write process, the control unit checks if the object record in which the data stored in the cache memory is being stored in the storage unit, if the object record is being stored in the storage unit, the data in the cache memory is written in the storage unit, and if not, the data in the cache memory is not written and such effect is notified to the data processing apparatus.

Abstract: A method and system of monitoring code as it is executed by a target processor is provided for debugging, etc. Standardized software code function preamble and postamble instructions are dynamically replaced with instructions that will generate a predetermined exception. This exception is of a type included in the standard instruction set of the target processor, such as a misalignment exception. The exception generates a branch to a conventional exception vector table. An exception routine is inserted into the vector table, and includes instruction(s) to disable the data and/or address caches. Subsequent instructions in the vector table execute the replaced preamble instruction and, with or without re-enabling the cache, branch back to the address of the program code immediately following the faulted preamble address. Instructions of the function executed while cache is disabled are executed on the bus where they are visible, as opposed to within cache.