Abstract: A write filter cache system for protecting a microprocessor core from soft errors and method thereof are provided. In one aspect, data coming from a processor core to be written in primary cache memory, for instance, L1 cache memory system, is buffered in a write filter cache placed between the primary cache memory and the processor core. The data from the write filter is move to the main cache memory only if it is verified that main thread's data is soft error free, for instance, by comparing the main thread's data with that of its redundant thread. The main cache memory only keeps clean data associated with accepted checkpoints.

Abstract: This invention involves a new method for preparing chitosan nano-particles. This method uses the nano-cavity technology so as to obtain pure chitosan nano-particles and pure chitosan nano-particle latex in a simple way.

Abstract: A multithreaded processor, fetch control for a multithreaded processor and a method of fetching in the multithreaded processor. Processor event and use (EU) signals are monitored for downstream pipeline conditions indicating pipeline execution thread states. Instruction cache fetches are skipped for any thread that is incapable of receiving fetched cache contents, e.g., because the thread is full or stalled. Also, consecutive fetches may be selected for the same thread, e.g., on a branch mis-predict. Thus, the processor avoids wasting power on unnecessary or place keeper fetches.

Abstract: A multithreaded processor, fetch control for a multithreaded processor and a method of fetching in the multithreaded processor. Processor event and use (EU) signs are monitored for downstream pipeline conditions indicating pipeline execution thread states. Instruction cache fetches are skipped for any thread that is incapable of receiving fetched cache contents, e.g., because the thread is full or stalled. Also, consecutive fetches may be selected for the same thread, e.g., on a branch mis-predict. Thus, the processor avoids wasting power on unnecessary or place keeper fetches.

Abstract: A multithreaded processor, fetch control for a multithreaded processor and a method of fetching in the multithreaded processor. Processor event and use (EU) signals are monitored for downstream pipeline conditions indicating pipeline execution thread states. Instruction cache fetches are skipped for any thread that is incapable of receiving fetched cache contents, e.g., because the thread is full or stalled. Also, consecutive fetches may be selected for the same thread, e.g., on a branch mis-predict. Thus, the processor avoids wasting power on unnecessary or place keeper fetches.

Abstract: An instruction cache (I-Cache) for a processor is configured to include a Branch Target Extension associated with each Instruction Sector. When an Instruction Sector is fetched, the Branch Target Extension is simultaneously fetched. If the Instruction Sector has a branch instruction that is predicted taken, then the branch target address in the branch extension is used to access the next Instruction Sector. In other embodiments, each Instruction Sector has a plurality of Branch Target Extensions each corresponding to a potential branch instruction in an Instruction Sector. In this case, the Branch Target Extensions are partitioned into an instruction index field for locating branch instruction in the Instruction Sector, a local predictor field for predicted taken status and a target address field for the branch target address. The least significant bits of the instruction fetch address are compared to the instruction indexes to determine a particular Branch Target Extension to use.

Abstract: A write filter cache system for protecting a microprocessor core from soft errors and method thereof are provided. In one aspect, data coming from a processor core to be written in primary cache memory, for instance, L1 cache memory system, is buffered in a write filter cache placed between the primary cache memory and the processor core. The data from the write filter is move to the main cache memory only if it is verified that main thread's data is soft error free, for instance, by comparing the main thread's data with that of its redundant thread. The main cache memory only keeps clean data associated with accepted checkpoints.

Abstract: A method for replacing cache lines in a computer system having a non-uniform set associative cache memory is disclosed. The method incorporates access latency as an additional factor into the existing ranking guidelines for replacement of a line, the higher the rank of the line the sooner that it is likely to be evicted from the cache. Among a group of highest ranking cache lines in a cache set, the cache line chosen to be replaced is one that provides the lowest latency access to a requesting entity, such as a processor. The distance separating the requesting entity from the memory partition where the cache line is stored most affects access latency.

Abstract: Arrangements and method for enabling and disabling cache bypass in a computer system with a cache hierarchy. Cache bypass status is identified with respect to at least one cache line. A cache line identified as cache bypass enabled is transferred to one or more higher level caches of the cache hierarchy, whereby a next higher level cache in the cache hierarchy is bypassed, while a cache line identified as cache bypass disabled is transferred to one or more higher level caches of the cache hierarchy, whereby a next higher level cache in the cache hierarchy is not bypassed. Included is an arrangement for selectively enabling or disabling cache bypass with respect to at least one cache line based on historical cache access information.

Abstract: A device for controlling power parameters in a microprocessor includes a resource activation control unit for controlling the maximum power of the microprocessor and two or more resources. The resource activation control unit controls the activation of the resources such that the consumed and dissipated power of the microprocessor does not exceed a power bound which is configurable to a predetermined value below the maximum power.

Abstract: Arrangements and methods for providing cache management. Preferably, a buffer arrangement is provided that is adapted to record incoming data into a first cache memory from a second cache memory, convey a data location in the first cache memory upon a prompt for corresponding data, in the event of a hit in the first cache memory, and refer to the second cache memory in the event of a miss in the first cache memory.

Abstract: A system and method for reducing latency in memory systems is provided. A copy way is established in a set of a set associative cache, which is physically closer to a requesting entity than other memory positions. Likely to be accessed data is copied to the copy way for subsequent access. In this way, subsequent accesses of the most likely data have their access time reduced due to the physical proximity of the data being close to the requesting entity. Methods herein further provide ranking and rearranging blocks in the cache based on coupled local and global least recently used (LRU) algorithms to reduce latency time.

Abstract: A hardware based method for determining when to migrate cache lines to the cache bank closest to the requesting processor to avoid remote access penalty for future requests. In a preferred embodiment, decay counters are enhanced and used in determining the cost of retaining a line as opposed to replacing it while not losing the data. In one embodiment, a minimization of off-chip communication is sought; this may be particularly useful in a CMP environment.

Abstract: Arrangements and method for enabling and disabling cache bypass in a computer system with a cache hierarchy. Cache bypass status is identified with respect to at least one cache line. A cache line identified as cache bypass enabled is transferred to one or more higher level caches of the cache hierarchy, whereby a next higher level cache in the cache hierarchy is bypassed, while a cache line identified as cache bypass disabled is transferred to one or more higher level caches of the cache hierarchy, whereby a next higher level cache in the cache hierarchy is not bypassed. Included is an arrangement for selectively enabling or disabling cache bypass with respect to at least one cache line based on historical cache access information.

Abstract: A multithreaded processor, fetch control for a multithreaded processor and a method of fetching in the multithreaded processor. Processor event and use (EU) signs are monitored for downstream pipeline conditions indicating pipeline execution thread states. Instruction cache fetches are skipped for any thread that is incapable of receiving fetched cache contents, e.g., because the thread is full or stalled. Also, consecutive fetches may be selected for the same thread, e.g., on a branch mis-predict. Thus, the processor avoids wasting power on unnecessary or place keeper fetches.

Abstract: An adaptive cache decay technique is disclosed that removes power from cache lines that have not been accessed for a variable time interval, referred to as the cache line decay interval, assuming that these cache lines are unlikely to be accessed in the future. The decay interval may be increased or decreased for each cache line to increase cache performance or save power, respectively. A default decay interval is initially established for the cache and the default decay interval may then be adjusted for a given cache line based on the performance of the cache line following a cache decay. The cache decay performance is evaluated by determining if a cache line was decayed too quickly. If a cache line is decayed and the same cache contents are again required, then the cache line was decayed too quickly and the cache line decay interval is increased. If a cache line is decayed and the cache line is then accessed to obtain a different cache content, the cache line decay interval can be decreased.

Abstract: A method for replacing cache lines in a computer system having a non-uniform set associative cache memory is disclosed. The method incorporates access latency as an additional factor into the existing ranking guidelines for replacement of a line, the higher the rank of the line the sooner that it is likely to be evicted from the cache. Among a group of highest ranking cache lines in a cache set, the cache line chosen to be replaced is one that provides the lowest latency access to a requesting entity, such as a processor. The distance separating the requesting entity from the memory partition where the cache line is stored most affects access latency.

Abstract: A system and method for reducing latency in memory systems is provided. A copy way is established in a set of a set associative cache, which is physically closer to a requesting entity than other memory positions. Likely to be accessed data is copied to the copy way for subsequent access. In this way, subsequent accesses of the most likely data have their access time reduced due to the physical proximity of the data being close to the requesting entity. Methods herein further provide ranking and rearranging blocks in the cache based on coupled local and global least recently used (LRU) algorithms to reduce latency time.

Abstract: An adaptive cache decay technique is disclosed that removes power from cache lines that have not been accessed for a variable time interval, referred to as the cache line decay interval, assuming that these cache lines are unlikely to be accessed in the future. The decay interval may be increased or decreased for each cache line to increase cache performance or save power, respectively. A default decay interval is initially established for the cache and the default decay interval may then be adjusted for a given cache line based on the performance of the cache line following a cache decay. The cache decay performance is evaluated by determining if a cache line was decayed too quickly. If a cache line is decayed and the same cache contents are again required, then the cache line was decayed too quickly and the cache line decay interval is increased. If a cache line is decayed and the cache line is then accessed to obtain a different cache content, the cache line decay interval can be decreased.