Abstract: An integrated circuit is provided with error detection circuitry and error repair circuitry. Error tolerance circuitry is responsive to a control parameter to selectively disable the error repair circuitry. The control parameter is dependent on the processing performed within the circuit. For example, the control parameter may be generated in dependence upon the program instruction being executed, the output signal value which is in error, the previous behavior of the circuit or in other ways.

Abstract: A data processing apparatus is provided which comprises a processor unit configured to perform data processing operations in response to a sequence of instructions and a storage unit configured to store data values for access by the processor unit when performing its data processing operations. Redundant error control data is stored in association with the data values, the redundant error control data enabling identification of an error in the data values. The data processing apparatus also comprises a data scrubbing unit configured to perform a data scrubbing process on at least a subset of the data values, the data scrubbing process comprising determining with reference to the redundant error control data if an error is present in that subset of data values and, where possible, correcting that error with reference to the redundant error control data.

Abstract: A data processing apparatus has a plurality of storage elements residing at different physical locations within the apparatus, and fault history circuitry for detecting local transient faults occurring in each storage element, and for maintaining global transient fault history data based on the detected local transient faults. Analysis circuitry monitors the global transient fault history data to determine, based on predetermined criteria, whether the global transient fault history data is indicative of random transient faults occurring within the data processing apparatus, or is indicative of a coordinated transient fault attack. The analysis circuitry is then configured to initiate a countermeasure action on determination of a coordinated transient fault attack.

Abstract: A data processing apparatus has a plurality of storage elements residing at different physical locations within the apparatus, and fault history circuitry for detecting local transient faults occurring in each storage element, and for maintaining global transient fault history data based on the detected local transient faults. Analysis circuitry monitors the global transient fault history data to determine, based on predetermined criteria, whether the global transient fault history data is indicative of random transient faults occurring within the data processing apparatus, or is indicative of a coordinated transient fault attack. The analysis circuitry is then configured to initiate a countermeasure action on determination of a coordinated transient fault attack.

Abstract: An integrated circuit is provided with error detection circuitry and error repair circuitry. Error tolerance circuitry is responsive to a control parameter to selectively disable the error repair circuitry. The control parameter is dependent on the processing performed within the circuit. For example, the control parameter may be generated in dependence upon the program instruction being executed, the output signal value which is in error, the previous behavior of the circuit or in other ways.

Abstract: An integrated circuit is provided with error detection circuitry and error repair circuitry. Error tolerance circuitry is responsive to a control parameter to selectively disable the error repair circuitry. The control parameter is dependent on the processing performed within the circuit. For example, the control parameter may be generated in dependence upon the program instruction being executed, the output signal value which is in error, the previous behavior of the circuit or in other ways.

Abstract: A data processing apparatus is provided having error code generation circuitry configured to generate an error code associated with a received data value, such that a bit change in the received data value can be known about by reference to the error code. Stored data values are stored in a data store and associated error codes are stored in an error code store. Error checking circuitry performs a verification operation on a stored data value and an associated error code to determine if an error has occurred in at least one of the stored data value and the associated error code during storage. The received data value comprises at least one additional bit with respect to the stored data value and the error checking circuitry is configured to reconstruct the at least one additional bit by reference to the stored data value and the associated error code.

Abstract: An integrated circuit is provided with error detection circuitry and error repair circuitry. Error tolerance circuitry is responsive to a control parameter to selectively disable the error repair circuitry. The control parameter is dependent on the processing performed within the circuit. For example, the control parameter may be generated in dependence upon the program instruction being executed, the output signal value which is in error, the previous behavior of the circuit or in other ways.

Abstract: An integrated circuit is provided with error detection circuitry and error repair circuitry. Error tolerance circuitry is responsive to a control parameter to selectively disable the error repair circuitry. The control parameter is dependent on the processing performed within the circuit. For example, the control parameter may be generated in dependence upon the program instruction being executed, the output signal value which is in error, the previous behavior of the circuit or in other ways.

Abstract: A data processing apparatus is provided having error code generation circuitry configured to generate an error code associated with a received data value, such that a bit change in the received data value can be known about by reference to the error code. Stored data values are stored in a data store and associated error codes are stored in an error code store. Error checking circuitry performs a verification operation on a stored data value and an associated error code to determine if an error has occurred in at least one of the stored data value and the associated error code during storage. The received data value comprises at least one additional bit with respect to the stored data value and the error checking circuitry is configured to reconstruct the at least one additional bit by reference to the stored data value and the associated error code.

Abstract: An apparatus comprises a dynamic random-access memory (DRAM) for storing data. Refresh control circuitry is provided to control the DRAM to periodically perform a refresh cycle for refreshing the data stored in each memory location of the DRAM. A refresh address sequence generator generates a refresh address sequence of addresses identifying the order in which memory locations of the DRAM are refreshed during the refresh cycle. To deter differential power analysis attacks on secure data stored in the DRAM, the refresh address sequence is generated with the addresses of at least a portion of the memory locations in a random order which varies from refresh cycle to refresh cycle.

Abstract: A data processing apparatus has a plurality of storage elements residing at different physical locations within the apparatus, and fault history circuitry for detecting local transient faults occurring in each storage element, and for maintaining global transient fault history data based on the detected local transient faults. Analysis circuitry monitors the global transient fault history data to determine, based on predetermined criteria, whether the global transient fault history data is indicative of random transient faults occurring within the data processing apparatus, or is indicative of a coordinated transient fault attack. The analysis circuitry is then configured to initiate a countermeasure action on determination of a coordinated transient fault attack.

Abstract: A processor 2 is responsive to a stream of program instructions to issue program instructions under control of scheduling circuitry 6 to respective execution units 24 for execution. The execution units 24 can include error detecting circuitry 32 for detecting a change in an output signal which occurs after the output signal has latched and during an error detecting period following the latching of the output signal. The scheduling circuitry 6 is arranged so as to suppress issue of program instructions to an execution unit 24 having such error detecting circuitry 32 on consecutive processing cycles.

Abstract: A data processing apparatus is provided which comprises a processor unit configured to perform data processing operations in response to a sequence of instructions and a storage unit configured to store data values for access by the processor unit when performing its data processing operations. Redundant error control data is stored in association with the data values, the redundant error control data enabling identification of an error in the data values. The data processing apparatus also comprises a data scrubbing unit configured to perform a data scrubbing process on at least a subset of the data values, the data scrubbing process comprising determining with reference to the redundant error control data if an error is present in that subset of data values and, where possible, correcting that error with reference to the redundant error control data.

Abstract: A data processing apparatus and method are provided for managing multiple program threads executed by processing circuitry. The multiple program threads include at least one high priority program thread and at least one lower priority program thread. At least one storage unit is shared between the multiple program threads and has multiple entries for storing information for reference by the processing circuitry when executing the program threads. Thread control circuitry is used to detect a condition indicating an adverse effect caused by a lower priority program thread being executed by the processing circuitry and resulting from sharing of the at least one storage unit between the multiple program threads.

Abstract: A data processing apparatus and method are provided for implementing a replacement scheme for entries of a storage unit. The data processing apparatus has processing circuitry for executing multiple program threads including at least one high priority program thread and at least one lower priority program thread. A storage unit is then shared between the multiple program threads and has multiple entries for storing information for reference by the processing circuitry when executing the program threads. A record is maintained identifying for each entry whether the information stored in that entry is associated with a high priority program thread or a lower priority program thread. Replacement circuitry is then responsive to a predetermined event in order to select a victim entry whose stored information is to be replaced.

Abstract: An instruction processing pipeline 6 is provided. This has error detection and error recovery circuitry 20 associated with one or more of the pipeline stages. If an error is detected within a signal value within that pipeline stage, then it can be repaired. Part of the error recovery may be to flush upstream program instructions from the instruction pipeline 6. When multi-threading, only those instructions from a thread including an instruction which has been lost as a consequence of the error recovery need to be flushed from the instruction pipeline 6. Instruction can also be selected for flushing in dependence upon characteristics such as privileged level, number of dependent instructions etc.

Abstract: A data processing apparatus and method are provided for detecting cache misses. The data processing apparatus has processing logic for executing a plurality of program threads, and a cache for storing data values for access by the processing logic. When access to a data value is required while executing a first program thread, the processing logic issues an access request specifying an address in memory associated with that data value, and the cache is responsive to the address to perform a lookup procedure to determine whether the data value is stored in the cache. Indication logic is provided which in response to an address portion of the address provides an indication as to whether the data value is stored in the cache, this indication being produced before a result of the lookup procedure is available, and the indication logic only issuing an indication that the data value is not stored in the cache if that indication is guaranteed to be correct.

Abstract: An instruction processing pipeline 6 is provided. This has error detection and error recovery circuitry 20 associated with one or more of the pipeline stages. If an error is detected within a signal value within that pipeline stage, then it can be repaired. Part of the error recovery may be to flush upstream program instructions from the instruction pipeline 6. When multi-threading, only those instructions from a thread including an instruction which has been lost as a consequence of the error recovery need to be flushed from the instruction pipeline 6. Instruction can also be selected for flushing in dependence upon characteristics such as privileged level, number of dependent instructions etc.

Abstract: A data processing apparatus is provided comprising processing circuitry for executing multiple program threads. At least one storage unit is shared between the multiple program threads and comprises multiple entries, each entry for storing a storage item either associated with a high priority program thread or a lower priority program thread. A history storage for retaining a history field for each of a plurality of blocks of the storage unit is also provided. On detection of a high priority storage item being evicted from the storage unit as a result of allocation to that entry of a lower priority storage item, the history field for the block containing that entry is populated with an indication of the evicted high priority storage item.