Abstract: Systems, methodologies, media, and other embodiments associated with mitigating the effects of context switch cache and TLB misses are described. One exemplary system embodiment includes a processor configured to run a multiprocessing, virtual memory operating system. The processor may be operably connected to a memory and may include a cache and a translation lookaside buffer (TLB) configured to store TLB entries. The exemplary system may include a context control logic configured to selectively copy data from the TLB to the data store for a first process being swapped out of the processor and to selectively copy data from the data store to the TLB for a second process being swapped into to the processor.

Abstract: A method, and a corresponding apparatus, mask error detection and correction latency during multilevel cache transfers. The method includes the steps of transferring error protection encoded data lines from a first cache, checking the error protection encoded data lines for errors, wherein the checking is completed after the transferring begins, receiving the error protection encoded data lines in a second cache, and upon detecting an error in a data line, preventing further transfer of the data line from the second cache.

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: A method and apparatus consolidate ports on a unified cache. The apparatus uses plurality of access connections with a single port of a memory. The apparatus comprises multiplexor and a logic circuit. The multiplexor is connected to the plurality of access connections. The multiplexor has a control input and a memory connection. The logic circuit produces an output signal tied to the control input. In another form, the apparatus comprises means for selectively coupling a single one of the plurality of access connections to the memory, and a means for controlling the means for coupling. Preferably, the plurality of access connections comprise a data connection and an instruction connection, and the memory is cache memory. The method uses a single memory access connection for a plurality of access types. The method accepts one or more memory access requests on one or more respective ones of a plurality of connections.

Abstract: A method, and a corresponding apparatus, mask error detection and correction latency during multilevel cache transfers. The method includes the steps of transferring error protection encoded data lines from a first cache, checking the error protection encoded data lines for errors, wherein the checking is completed after the transferring begins, receiving the error protection encoded data lines in a second cache, and upon detecting an error in a data line, preventing further transfer of the data line from the second cache.

Abstract: Methods and apparatus mask the latency of error detection and/or error correction applied to data transferred between a first memory and a second memory. The method comprises determining whether there is an error in a data unit in the first memory; transferring data based on the data unit from the first memory to a second memory, wherein the transferring step commences before completion of the determining step; and disabling at least part of the second memory if the determining step detects an error in the data unit. The disabling step may be accomplished, for example, by disabling the buffering of an address of the data unit or stalling the second memory.

Abstract: Disclosed is a device and method for testing of a program or a design of an electronic device comprising digital logic circuitry. The method comprises testing the design of software or an electronic device and injecting, after initiation of the testing step, a predetermined error pattern into a value operated upon by the design of the digital logic circuitry. In a preferred embodiment, the software is a simulation of the design of a processor having a cache with error detection and/or correction circuitry. A triggering condition is preferably a cache hit, in response to which a detectable error is injected into the cache. The simulated operations of the model are observed to determine whether the injected error is detected, as should happen if the processor's error detection circuitry has been designed properly. In another respect, the invention is an apparatus, or computer software embedded on a computer readable medium, for testing a program comprising an error detector.