Abstract: Recovery circuits react to errors in a processor core by waiting for an error-free completion of any pending store-conditional instruction or a cache-inhibited load before ceasing to checkpoint or backup progress of a processor core. Recovery circuits remove the processor core from the logical configuration of the symmetric multiprocessor system, potentially reducing propagation of errors to other parts of the system. The processor core is reset and the checkpointed values may be restored to registers of the processor core. The core processor is allowed not just to resume execution just prior to the instructions that failed to execute correctly the first time, but is allowed to operate in a reduced execution mode for a preprogrammed number of groups. If the preprogrammed number of instruction groups execute without error, the processor core is allowed to resume normal execution.

Abstract: A logic gate is described that implements complex logic within a memory array. The logic gate receives at least three of a first storage cell signal, a second storage cell signal, a first external signal, or a second external signal at a first input circuitry and second input circuitry. The logic gate then performs one of a set of logic functions using the first storage cell signal, the second storage cell signal, the first external signal, or the second external signal. The set of logic functions includes at least one of a matching function, an OR-AND function, or an AND function.

Abstract: A register file is often used within integrated circuitry to temporarily hold data. Sometimes this data needs to be retained within the register file for a period of time, such as when there is a stall operation. Conventional register files have utilized a hold multiplexor to perform such a stall operation. The multiplexor however inserts a delay that is undesirable in high performance integrated circuitry. The multiplexor is replaced with a tri-state inverter coupled to the global bit line of the register file, which minimizes this additional delay from the register file data access time.

Abstract: A method, system and apparatus for detecting soft errors in non-dataflow circuits. In a preferred embodiment, input is received at a latch system. The latch system consists of two pairs of latches. The second pair of latches is parallel to the first pair of latches. Both pairs of latches capture the input. However, the second pair of latches captures the input later in time relative to the first pair of latches latch. The captured input is then transferred from the first latch in each pair of latches to the second latch in each pair of latches. A comparison is made of the input in the two second latches. If the input captured in the two second latches is not the same, then a message is sent to a recovery unit.

Abstract: Recovery circuits react to errors in a processor core by waiting for an error-free completion of any pending store-conditional instruction or a cache-inhibited load before ceasing to checkpoint or backup progress of a processor core. Recovery circuits remove the processor core from the logical configuration of the symmetric multiprocessor system, potentially reducing propagation of errors to other parts of the system. The processor core is reset and the checkpointed values may be restored to registers of the processor core. The core processor is allowed not just to resume execution just prior to the instructions that failed to execute correctly the first time, but is allowed to operate in a reduced execution mode for a preprogrammed number of groups. If the preprogrammed number of instruction groups execute without error, the processor core is allowed to resume normal execution.

Abstract: A logic gate is described that implements complex logic within a memory array. The logic gate receives at least three of a first storage cell signal, a second storage cell signal, a first external signal, or a second external signal at a first input circuitry and second input circuitry. The logic gate then performs one of a set of logic functions using the first storage cell signal, the second storage cell signal, the first external signal, or the second external signal. The set of logic functions includes at least one of a matching function, an OR-AND function, or an AND function.

Abstract: A method and apparatus are provided for dispatch group checkpointing in a microprocessor, including provisions for handling partially completed dispatch groups and instructions which modify system coherent state prior to completion. An instruction checkpoint retry mechanism is implemented to recover from soft errors in logic. The processor is able to dispatch fixed point unit (FXU), load/store unit (LSU), and floating point unit (FPU) or vector multimedia extension (VMX) instructions on the same cycle. Store data is written to a store queue when a store instruction finishes executing. The data is held in the store queue until the store instruction is checkpointed, at which point it can be released to the coherently shared level 2 (L2) cache.

Abstract: A logic gate is described that implements complex logic within a memory array. The logic gate receives at least three of a first storage cell signal, a second storage cell signal, a first external signal, or a second external signal at a first input circuitry and second input circuitry. The logic gate then performs one of a set of logic functions using the first storage cell signal, the second storage cell signal, the first external signal, or the second external signal. The set of logic functions includes at least one of a matching function, an OR-AND function, or an AND function.

Abstract: Recovery circuits react to errors in a processor core by waiting for an error-free completion of any pending store-conditional instruction or a cache-inhibited load before ceasing to checkpoint or backup progress of a processor core. Recovery circuits remove the processor core from the logical configuration of the symmetric multiprocessor system, potentially reducing propagation of errors to other parts of the system. The processor core is reset and the checkpointed values may be restored to registers of the processor core. The core processor is allowed not just to resume execution just prior to the instructions that failed to execute correctly the first time, but is allowed to operate in a reduced execution mode for a preprogrammed number of groups. If the preprogrammed number of instruction groups execute without error, the processor core is allowed to resume normal execution.

Abstract: A register file is often used within integrated circuitry to temporarily hold data. Sometimes this data needs to be retained within the register file for a period of time, such as when there is a stall operation. Conventional register files have utilized a hold multiplexor to perform such a stall operation. The multiplexor however inserts a delay that is undesirable in high performance integrated circuitry. The multiplexor is replaced with a tri-state inverter coupled to the global bit line of the register file, which minimizes this additional delay from the register file data access time.

Abstract: A register file is often used within integrated circuitry to temporarily hold data. Sometimes this data needs to be retained within the register file for a period of time, such as when there is a stall operation. Conventional register files have utilized a hold multiplexor to perform such a stall operation. The multiplexor however inserts a delay that is undesirable in high performance integrated circuitry. The multiplexor is replaced with a tri-state inverter coupled to the global bit line of the register file, which minimizes this additional delay from the register file data access time.

Abstract: A logic gate is described that implements complex logic within a memory array. The logic gate receives at least three of a first storage cell signal, a second storage cell signal, a first external signal, or a second external signal at a first input circuitry and second input circuitry. The logic gate then performs one of a set of logic functions using the first storage cell signal, the second storage cell signal, the first external signal, or the second external signal. The set of logic functions includes at least one of a matching function, an OR-AND function, or an AND function.

Abstract: A method and apparatus for ensuring proper operation of a dynamic circuit is provided. A dynamic circuit instance has a plurality of outputs connected to a respective one of a plurality of leakage detector circuits. An output of each leakage detector circuit is connected with a respective one of a plurality of keeper circuits that reside at the dynamic circuit. Each of the plurality of keeper circuits has a unique size ratio with respect to a logic element size of the dynamic circuit.

Abstract: A register file method incorporating read-after-write blocking using detection cells provides improved read access times in high performance register files. One or more detection cells identical to the register file cells and located in the register file array are used to control the read operation in the register file by configuring the detection cells to either alternate value at each write or change to a particular value after a write and then detecting when the write has completed by detecting the state change of an active detection cell. The state change detection can be used to delay the leading edge of a read strobe or may be used in the access control logic to delay generation of a next read strobe. The register file thus provides a scalable design that does not have to be tuned for each application and that tracks over voltage and clock skew variation.

Abstract: A CAM system is disclosed in which requests for address translation are provided as input search data to a dynamic compare bitline generator. The dynamic compare bitline generator also receives a compare mask and applies the compare mask to associated input search data bits on a per bit basis. The mask contains information that specifies a selected page size and a selected logic mode that can be applied to a compare array in which the specified search is conducted. The compare array is coupled to a data array to which the compare array indicates a result of the search.

Abstract: An apparatus for implementing a least-recently used (LRU) mechanism in a multi-port cache memory includes an LRU array and a shift decoder. The LRU array has multiple entries. The shift decoder includes a shifting means for shifting the entries within the LRU array. The shifting means shifts a current one of the entries and adjacent entries once, and loading new address, in response to a single cache hit in the current one of the entries. The shifting means shifts a current one of the entries and adjacent entries once, and loading an address of only one of multiple requesters into the most-recently used (MRU) entry, in response to multiple cache hits in the current one of the entries. The shifting means shifts all subsequent entries, including the current entries, n times, and loading addresses of all requesters contributed to the multiple cache hits in consecutive entries into the MRU entry and subsequent entries, in response to multiple cache hits in consecutive entries.

Abstract: A dynamic-static logical control element for signaling an interval between the end of a control signal and a logical evaluation provides a compact circuit for blocking the indication of a non-evaluated state of a dynamic logic gate until a control signal has ended. The control signal is connected to a precharge input of the control element and a summing node is connected to one or more evaluation trees and to the control element output via an inverter. The inverter is connected to an override circuit that forces the output of the control element to a state opposite the precharge state until the control signal has ended. The output of the control element then assumes a state corresponding to the precharge state until an evaluation occurs. The control element output thus produces a window signal indicating the interval between the end of the control signal and the evaluation.

Abstract: A register file apparatus and method incorporating read-after-write blocking using detection cells provides improved read access times in high performance register files. One or more detection cells identical to the register file cells and located in the register file array are used to control the read operation in the register file by configuring the detection cells to either alternate value at each write or change to a particular value after a write and then detecting when the write has completed by detecting the state change of an active detection cell. The state change detection can be used to delay the leading edge of a read strobe or may be used in the access control logic to delay generation of a next read strobe. The register file thus provides a scalable design that does not have to be tuned for each application and that tracks over voltage and clock skew variation.

Abstract: A method and apparatus for ensuring proper operation of a dynamic circuit is provided. A dynamic circuit instance has a plurality of outputs connected to a respective one of a plurality of leakage detector circuits. An output of each leakage detector circuit is connected with a respective one of a plurality of keeper circuits that reside at the dynamic circuit. Each of the plurality of keeper circuits has a unique size ratio with respect to a logic element size of the dynamic circuit.

Abstract: A register file method incorporating read-after-write blocking using detection cells provides improved read access times in high performance register files. One or more detection cells identical to the register file cells and located in the register file array are used to control the read operation in the register file by configuring the detection cells to either alternate value at each write or change to a particular value after a write and then detecting when the write has completed by detecting the state change of an active detection cell. The state change detection can be used to delay the leading edge of a read strobe or may be used in the access control logic to delay generation of a next read strobe. The register file thus provides a scalable design that does not have to be tuned for each application and that tracks over voltage and clock skew variation.