Abstract: There is provided an apparatus, method and medium for data processing. The apparatus comprises a register file comprising a plurality of data registers, and frontend circuitry responsive to an issued instruction, to control processing circuitry to perform a processing operation to process an input data item to generate an output data item. The processing circuitry is responsive to a first encoding of the issued instruction specifying a data register, to read the input data item from the data register, and/or write the output data item to the data register. The processing circuitry is responsive to a second encoding of the issued instruction specifying a buffer-region of the register file for storing a queue of data items, to perform the processing operation and to perform a dequeue operation to dequeue the input data item from the queue, and/or perform an enqueue operation to enqueue the output data item to the queue.

Abstract: One or more triggered-instruction processing elements are provided, a given triggered-instruction processing element comprising execution circuitry to execute processing operations in response to instructions according to a triggered instruction architecture. Input channel processing circuitry receives a given tagged data item (comprising a data value and a tag value) for a given input channel, and in response controls enqueuing of the data value of the given tagged data item to a selected buffer structure selected from among at least two buffer structures mapped onto register storage accessible to one or more of the triggered-instruction processing elements in response to a computation instruction for controlling performance of a computation operation. The selected buffer structure is selected based at least on the tag value, so data values of tagged data items specifying different tag values for the given input channel are allocatable to different buffer structures.

Abstract: An apparatus, method and computer program, the apparatus comprising processing circuitry to execute instructions, issue circuitry to issue the instructions for execution by the processing circuitry, and candidate instruction storage circuitry to store a plurality of condition-dependent instructions, each specifying at least one condition. The issue circuitry is configured to issue a given condition-dependent instruction in response to a determination or a prediction of the at least one condition specified by the given condition-dependent instruction being met, and when the given condition-dependent instruction is a sequence-start instruction, the issue circuitry is responsive to the determination or prediction to issue a sequence of instructions comprising the sequence-start instruction and at least one subsequent instruction.

Abstract: There is provided an apparatus, method and medium for data processing. The apparatus comprises a register file comprising a plurality of data registers, and frontend circuitry responsive to an issued instruction, to control processing circuitry to perform a processing operation to process an input data item to generate an output data item. The processing circuitry is responsive to a first encoding of the issued instruction specifying a data register, to read the input data item from the data register, and/or write the output data item to the data register. The processing circuitry is responsive to a second encoding of the issued instruction specifying a buffer-region of the register file for storing a queue of data items, to perform the processing operation and to perform a dequeue operation to dequeue the input data item from the queue, and/or perform an enqueue operation to enqueue the output data item to the queue.

Abstract: A masked-vector-comparison instruction specifies a source vector operand comprising a plurality of source data elements, a mask value, and a comparison target operand. In response to the masked-vector-comparison instruction, an instruction decoder 10 controls processing circuitry 16 to: for each active source data element of the source vector operand, determine whether the active source data element satisfies a comparison condition, based on a masked comparison between one or more compared bits of the active source data element and one or more compared bits of the comparison target operand, the mask value specifying a pattern of compared bits and non-compared bits within the comparison target operand and the active source data element; and generate a result value indicative of which of the source data elements of the source vector operand, if any, is an active source data element satisfying the comparison condition. This instruction is useful for variable length decoding operations.

Abstract: An entropy calculation for certainty-based classification networks is provided. An integer operand p is received. A remainder portion of the integer operand p is determined based on a range reduction operation. A scaled integer operand is determined based on the integer operand p. An index for a data structure, such as, for example, a look-up table (LUT), is determined based on the remainder portion of the integer operand p and a parameter N associated with the data structure. A data structure value in the data structure is looked up based on the index. A scaled entropy value is generated by adding the data structure value to the scaled integer operand. An entropy value is determined based on the scaled entropy value, and the entropy value is output.

Abstract: A certainty-based prediction apparatus and method are provided. A plurality of main classifier (MC) modules each predict an MC predicted class based on input data, and determine an MC certainty. Each MC module processes a pre-trained, machine learning main classifier having at least one expert class and a plurality of non-expert classes. An expert classifier (EC) module associated with each expert class predicts an EC predicted class based on the input data. Each EC module processes a pre-trained, machine learning expert classifier having two classes including an associated expert class and a residual class that includes any non-associated expert classes and the plurality of non-expert classes. A final predicted class decision module determines a final predicted class and a final certainty based on each MC predicted class, each MC certainty and each EC predicted class. The final predicted class and the final certainty are output.

Abstract: An apparatus comprises a plurality of redundant processing units to perform data processing redundantly in lockstep; common mode fault detection circuitry to detect an event indicative of a potential common mode fault affecting each of the plurality of redundant processing units; a memory shared between the plurality of redundant processing units; and memory checking circuitry to perform a memory scanning operation to scan at least part of the memory for errors; in which the memory checking circuitry performs the memory scanning operation in response to a common mode fault signal generated by the common mode fault detection circuitry indicating that the event indicative of a potential common mode fault has been detected.

Abstract: An apparatus has a processing pipeline (2) comprising an execute stage (30) and at least one front end stage (10), (20), (25) for controlling which micro operations are issued to the execute stage. The pipeline has an intra-core lockstep mode of operation in which the at least one front end stage (10), (20), (25) issues micro operations for controlling the execute stage (30) to perform main processing and checker processing. The checker processing comprises redundant operations corresponding to associated main operations of at least part of the main processing. Error handling circuitry (200), (210) is responsive to the detection of a mismatch between information associated with given checker and main operations to trigger a recovery operation to correct an error and continue forward progress of the main processing.

Abstract: Briefly, example methods, apparatuses, and/or articles of manufacture are disclosed that may be implemented, in whole or in part, to determine indicators of potential errors in a multi-processing core lockstep computing device comprising a plurality of processing cores, based, at least in part, on observations of output signals generated by at least two processing cores of the plurality of processing cores. A built-in self-test (BIST) procedure may then be based, at least in part, on the determining indicators.

Abstract: An apparatus comprises a plurality of redundant processing units (4) to perform data processing redundantly in lockstep; common mode fault detection circuitry *6, 22) to detect an event indicative of a potential common mode fault affecting each of the plurality of redundant processing units; a memory (10) shared between the plurality of redundant processing units; and memory checking circuitry (30) to perform a memory scanning operation to scan at least part of the memory for errors; in which the memory checking circuitry (30) performs the memory scanning operation in response to a common mode fault signal generated by the common mode fault detection circuitry (6, 22) indicating that the event indicative of a potential common mode fault has been detected.

Abstract: A buffer (72), (74), (76), (60), (78), (20), (82-90) has a number of entries for buffering items associated with data processing operations. Buffer control circuitry (100) has a redundant allocation mode in which, on allocating a given item to the buffer, the item is allocated to two or more redundant entries of the buffer. On reading or draining an item from the buffer, the redundant entries are compared and an error handling response is triggered if a mismatch is detected. By effectively reducing the buffer capacity, this simplifies testing for faults in buffer entries.

Abstract: An apparatus is provided to measure vulnerability of a circuit to transient errors. The circuit includes processing circuitry and a plurality of flops. The apparatus includes categorisation obtaining circuitry that obtains a vulnerability categorisation of the flops. The vulnerability categorisation indicates whether each flop is vulnerable, conditionally vulnerable, or isolated. Analysis circuitry determines, for at least one cycle of the processing circuitry, a set of the flops that are currently vulnerable, based on the vulnerability categorisation of the flops.

Abstract: Aspects of the present disclosure relate to an apparatus comprising processing circuitry to execute a plurality of code sequences, and configuration storage to store mode control data for the processing circuitry. When the processing circuitry is executing one of said plurality of code sequences, the mode control data is set so as to identify a high resilience mode of operation of the processing circuitry where usage of one or more components of the processing circuitry is modified so as to increase resilience of the processing circuitry to faults relative to a default mode of operation of the processing circuitry.

Abstract: Examples of the present disclosure relate to a method for anomaly response in a system on chip. The method comprises measuring a magnitude of a transient anomaly event in an operating condition of the system on chip. Based on the magnitude it is determined, for each of a plurality of components of the system on chip, an indication of susceptibility of that component to an anomaly event of the measured magnitude. Based on the determined indications of susceptibility for each of the plurality of components, an anomaly response action is determined. The method then comprises performing the anomaly response action.

Abstract: An apparatus is provided to measure vulnerability of a circuit to transient errors. The circuit includes processing circuitry and a plurality of flops. The apparatus includes categorisation obtaining circuitry that obtains a vulnerability categorisation of the flops. The vulnerability categorisation indicates whether each flop is vulnerable, conditionally vulnerable, or isolated. Analysis circuitry determines, for one cycle of the processing circuitry, a set of the flops that are currently vulnerable, based on the vulnerability categorisation of the flops.

Abstract: Briefly, example methods, apparatuses, and/or articles of manufacture are disclosed that may be implemented, in whole or in part, to determine indicators of potential errors in a multi-processing core lockstep computing device comprising a plurality of processing cores, based, at least in part, on observations of output signals generated by at least two processing cores of the plurality of processing cores. A built-in self-test (BIST) procedure may then be based, at least in part, on the determining indicators.

Abstract: A buffer (72), (74), (76), (60), (78), (20), (82-90) has a number of entries for buffering items associated with data processing operations. Buffer control circuitry (100) has a redundant allocation mode in which, on allocating a given item to the buffer, the item is allocated to two or more redundant entries of the buffer. On reading or draining an item from the buffer, the redundant entries are compared and an error handling response is triggered if a mismatch is detected. By effectively reducing the buffer capacity, this simplifies testing for faults in buffer entries.

Abstract: An apparatus has a processing pipeline (2) comprising an execute stage (30) and at least one front end stage (10), (20), for controlling which micro operations are issued to the execute stage. The pipeline has an intra-core lockstep mode of operation in which the at least one front end stage (10), (20), (25) issues micro operations for controlling the execute stage (30) to perform main processing and checker processing. The checker processing comprises redundant operations corresponding to associated main operations of at least part of the main processing. Error handling circuitry (200), (210) is responsive to the detection of a mismatch between information associated with given checker and main operations to trigger a recovery operation to correct an error and continue forward progress of the main processing.

Abstract: An apparatus is provided to measure vulnerability of a circuit to transient errors. The circuit includes processing circuitry and a plurality of flops. The apparatus includes categorisation obtaining circuitry that obtains a vulnerability categorisation of the flops. The vulnerability categorisation indicates whether each flop is vulnerable, conditionally vulnerable, or isolated. Analysis circuitry determines, for one cycle of the processing circuitry, a set of the flops that are currently vulnerable, based on the vulnerability categorisation of the flops.