Abstract: A cache includes a cache pipeline, a request receiver configured to receive off chip coherency requests from an off chip cache and a plurality of state machines coupled to the request receiver. The cache also includes an arbiter coupled between the plurality of state machines and the cache pipe line and is configured to give priority to off chip coherency requests as well as a counter configured to count the number of coherency requests sent from the cache pipeline to a lower level cache. The cache pipeline is halted from sending coherency requests when the counter exceeds a predetermined limit.

Abstract: A computer implemented method of optimizing sequential data fetches in a computer system is provided. The method includes fetching a data segment from a main memory, the data segment having a plurality of target data entries; extracting a first portion of the data segment and storing the first portion into a target data cache, the first portion having a first target data entry; and storing the data segment into an intermediate cache line buffer in communication with the target data cache to enable subsequent fetches to a number of target data entries in the data segment.

Abstract: A computer-implemented method for managing data transfer in a multi-level memory hierarchy that includes receiving a fetch request for allocation of data in a higher level memory, determining whether a data bus between the higher level memory and a lower level memory is available, bypassing an intervening memory between the higher level memory and the lower level memory when it is determined that the data bus is available, and transferring the requested data directly from the higher level memory to the lower level memory.

Abstract: Methods of error correction code (ECC) debugging may comprise detecting whether a bit error has occurred; determining which bit or bits were in error; and using the bit error information for debug. The method may further comprise comparing ECC syndromes against one or more ECC syndrome patterns. The method may allow for accumulating bit error information, comparing error bit failures against a pattern, trapping data, counting errors, determining pick/drop information, or stopping the machine for debug.

Abstract: Optimizing EDRAM refresh rates in a high performance cache architecture. An aspect of the invention includes receiving a plurality of first signals. A refresh request is transmitted via a refresh requestor to a cache memory at a first refresh rate which includes an interval, including a subset of the first signals. The first refresh rate corresponds to a maximum refresh rate. A refresh counter is reset based on receiving a second signal. The refresh counter is incremented after receiving each of a number of refresh requests. A current count is transmitted from a refresh counter to the refresh requestor based on receiving a third signal. The refresh request is transmitted at a second refresh rate, which is less than the first refresh rate. The refresh request is transmitted based on receiving the current count from the refresh counter and determining that the current count is greater than a refresh threshold.

Abstract: The method includes initiating a processor request to a cache in a requesting node and broadcasting the processor request to remote nodes when the processor request encounters a local cache miss, performing a directory search of each remote cache to determine a state of a target line's address and an ownership state of a specified address, returning the state of the target line to the requesting node and forming a combined response, and broadcasting the combined response to each remote node. During a fetch operation, when the directory search indicates an IM or a Target Memory node on a remote node, data is sourced from the respective remote cache and forwarded to the requesting node while protecting the data, and during a store operation, the data is sourced from the requesting node and protected while being forwarded to the IM or the Target Memory node after coherency has been established.

Abstract: Controlling refresh request transmission rates in a cache comprising: a refresh requestor configured to transmit a refresh request to a cache memory at a first refresh rate, the first refresh rate comprising an interval, the interval comprising receiving a plurality of first signals, the first refresh rate corresponding to a maximum refresh rate, and a refresh counter operatively coupled to the refresh requestor and configured to reset in response to receiving a second signal, increment in response to receiving each of a plurality of refresh requests from the refresh requestor, and reset and transmit a current count to the refresh requestor in response to receiving a third signal, wherein the refresh requestor is configured to transmit a refresh request at a second refresh rate, in response to receiving the current count from the refresh counter and determining that the current count is greater than a refresh threshold.

Abstract: A two pipe pass method for least recently used (LRU) compartment capture in a multiprocessor system. The method includes receiving a fetch request via a requesting processor and accessing a cache directory based on the received fetch request, performing a first pipe pass by determining whether a fetch hit or a fetch miss has occurred in the cache directory, and determining an LRU compartment associated with a specified congruence class of the cache directory based on the fetch request received, when it is determined that a fetch miss has occurred, and performing a second pipe pass by using the LRU compartment determined and the specified congruence class to access the cache directory and to select an LRU address to be cast out of the cache directory.

Abstract: Improved access to retained data useful to a system is accomplished by managing data flow through cache associated with the processor(s) of a multi-node system. A data management facility operable with the processors and memory array directs the flow of data from the processors to the memory array by determining the path along which data evicted from a level of cache close to one of the processors is to return to a main memory and directing evicted data to be stored, if possible, in a horizontally associated cache.

Abstract: Optimizing refresh request transmission rates in a high performance cache comprising: a refresh requestor configured to transmit a refresh request to a cache memory at a first refresh rate, the first refresh rate comprising an interval, the interval comprising receiving a plurality of first signals, the first refresh rate corresponding to a maximum refresh rate, and a refresh counter operatively coupled to the refresh requestor and configured to reset in response to receiving a second signal, increment in response to receiving each of a plurality of refresh requests from the refresh requestor, and reset and transmit a current count to the refresh requestor in response to receiving a third signal, wherein the refresh requestor is configured to transmit a refresh request at a second refresh rate, in response to receiving the current count from the refresh counter and determining that the current count is greater than a refresh threshold.

Abstract: A pipelined processing device includes: a device controller configured to receive a request to perform an operation; a plurality of subcontrollers configured to receive at least one instruction associated with the operation, each of the plurality of subcontrollers including a counter configured to generate an active time value indicating at least a portion of a time taken to process the at least one instruction; a pipeline processor configured to receive and process the at least one instruction, the pipeline processor configured to receive the active time value; and a shared pipeline storage area configured to store the active time value for each of the plurality of subcontrollers.

Abstract: A cache includes a cache pipeline, a request receiver configured to receive off chip coherency requests from an off chip cache and a plurality of state machines coupled to the request receiver. The cache also includes an arbiter coupled between the plurality of state machines and the cache pipe line and is configured to give priority to off chip coherency requests as well as a counter configured to count the number of coherency requests sent from the cache pipeline to a lower level cache. The cache pipeline is halted from sending coherency requests when the counter exceeds a predetermined limit.

Abstract: A method of debugging a memory element is provided. The method includes initializing a line fetch controller with at least one of write data and read data; utilizing at least two separate clocks for performing at least one of write requests and read requests based on the at least one of the write data and the read data; and debugging the memory element based on the at least one of write requests and read requests.

Abstract: Various embodiments of the present invention manage access to a cache memory. In or more embodiments a request for a targeted interleave within a cache memory is received. The request is associated with an operation of a given type. The target is determined to be available. The request is granted in response to the determining that the target is available. A first interleave availability table associated with a first busy time associated with the cache memory is updated based on the operation associated with the request in response to granting the request. A second interleave availability table associated with a second busy time associated with the cache memory is updated based on the operation associated with the request in response to granting the request.

Abstract: A computer-implemented method for managing data transfer in a multi-level memory hierarchy that includes receiving a fetch request for allocation of data in a higher level memory, determining whether a data bus between the higher level memory and a lower level memory is available, bypassing an intervening memory between the higher level memory and the lower level memory when it is determined that the data bus is available, and transferring the requested data directly from the higher level memory to the lower level memory.

Abstract: Defining a set of correctable error and uncorrectable error syndrome code points, generating an error correction code (ECC) syndrome decode, regarding the uncorrectable error syndrome code points as “don't cares” and logically minimizing the ECC syndrome decode for the determination of the correctable error syndrome code points based on the regarding of the uncorrectable error syndrome code points as the “don't cares” whereby output data can be ignored for the uncorrectable error syndrome code points.

Abstract: A memory system is provided. The memory system includes a memory element that is configured to selectively output data stored to and data fetched from the memory element. An error checking station is configured to receive the data stored to and the data fetched from the memory element. The error checking station is further configured to perform error checking on the data.

Abstract: Dynamic re-allocation of cache buffer slots includes moving data out of a reserved buffer slot upon detecting an error in the reserved buffer slot, creating a new buffer slot, and storing the data moved out of the reserved buffer slot in the new buffer slot.

Abstract: User-controlled targeted cache purging includes receiving a request to perform an operation to purge data from a cache, the request including an index identifier identifying an index associated with the cache. The index specifies a portion of the cache to be purged. The user-controlled targeted cache purging also includes purging the data from the cache, and providing notification of successful completion of the operation.

Abstract: A computer implemented method of optimizing sequential data fetches in a computer system is provided. The method includes fetching a data segment from a main memory, the data segment having a plurality of target data entries; extracting a first portion of the data segment and storing the first portion into a target data cache, the first portion having a first target data entry; and storing the data segment into an intermediate cache line buffer in communication with the target data cache to enable subsequent fetches to a number target data entries in the data segment.