Abstract:
A technique includes receiving, by a device a command, wherein a response to the command is expected from the device within a predetermined response time. The device may selectively generate an error signal to allow time for the device to complete processing the command.
Abstract:
An apparatus and method are described for detecting and correcting data fetch errors within a processor core. For example, one embodiment of an instruction processing apparatus for detecting and recovering from data fetch errors comprises: at least one processor core having a plurality of instruction processing stages including a data fetch stage and a retirement stage; and error processing logic in communication with the processing stages to perform the operations of: detecting an error associated with data in response to a data fetch operation performed by the data fetch stage; and responsively performing one or more operations to ensure that the error does not corrupt an architectural state of the processor core within the retirement stage.
Abstract:
One embodiment of the present invention provides a system that facilitates error correction within a register file in a central processing unit (CPU). During execution of an instruction by the CPU, the system retrieves a dataword and an associated syndrome from a source register in the register file. Next, the system uses information in the dataword and the associated syndrome to detect, and if necessary correct, an error in the dataword or associated syndrome. Note that this error detection and correction takes place in parallel with using the dataword to perform a computational operation specified by the instruction. If an error is detected, the system prevents the instruction from performing a writeback to a destination register in the register file. The system also writes a corrected dataword to the source register in the register file. Next, the system flushes the instruction pipeline, and restarts execution of the instruction so that the corrected dataword is retrieved for the computational operation.
Abstract:
A fault tolerant computer system includes at least two central processing units each having a cache memory and a parity error detector adapted to sense parity errors in blocks of information read from and write to cache and to issue a cache parity read or write error flag if a parity error is sensed. A system bus couples the CPU to a System Control Unit having a parity error correction facility, and a memory bus couples the SCU to a main memory. An error recovery control feature distributed across the CPU, a Service Processor and the operating system software is responsive to the sensing of a read parity error flag in a sending CPU and a write parity error flag in a receiving CPU in conjunction with a siphon operation for transferring the faulting block from the sending CPU to main memory via the SCU (in which given faulting block is corrected) and for subsequently transferring the corrected memory block from main memory to the receiving CPU when a retry is instituted.
Abstract:
A processor capable of concurrently processing sequences of instructions of a plurality of threads, which realizes a retry success rate similar to that of a processor for processing a sequence of instructions of a single thread. An arithmetic device (200) includes an instruction execution circuit (201) for executing the plurality of threads and an execution control circuit (202) for controlling execution conditions and re-execution of each thread.
Abstract:
A processor core (100) includes an instruction decode unit (140) that may dispatch a same integer instruction stream to a plurality of integer execution units (154a, 154b) and may consecutively dispatch a same floating-point instruction stream to a floating-point unit (160). The integer execution units may operate in lock-step such that during each clock cycle, each respective integer execution unit executes the same integer instruction. The floating-point unit may execute the same floating-point instruction stream twice. Prior to the integer instructions retiring, compare logic (158a, 158b, 163) may detect a mismatch between execution results from each of the integer execution units. In addition, prior to the results of the floating-point instruction stream transferring out of the floating-point unit, the compare logic may also detect a mismatch between results of execution of each consecutive floating-point instruction stream. Further, in response to detecting any mismatch, the compare logic may cause instructions causing the mismatch to be re-executed.
Abstract:
Embodiments include a system, an apparatus, a device, and a method. An apparatus includes a synchronous circuit including a first subcircuit powered by a first power plane having a first power plane voltage and a second subcircuit powered by a second power plane having a second power plane voltage. The apparatus also includes an error detector operable to detect an incidence of a computational error occurring in the first subcircuit. The apparatus includes a controller operable to change the first power plane voltage based upon the detected incidence of a computational error. The apparatus also includes a power supply configured to electrically couple with a portable power source and operable to provide a selected one of at least two voltages to the first power plane in response to the controller.