Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 1014, a non-delayed signal-capture element 1016, a delayed signal-capture element 1018 and a comparator 1024. The non-delayed signal-capture element 1016 captures an output from the processing logic 1014 at a non-delayed capture time. At a later delayed capture time, the delayed signal-capture element 1018 also captures a value from the processing logic 1014. An error detection circuit 1026 and error correction circuit 1028 detect and correct random errors in the delayed value and supplies an error-checked delayed value to the comparator 1024. The comparator 1024 compares the error-checked delayed value and the non-delayed value and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the error-checked delayed value.

Abstract: An integrated circuit 2 has a specified range of runtime-variable operating parameters. Data processing circuits 4 within the integrated circuit 2 have associated error detection and error repair mechanisms 6. When operating within a narrow typical-case range of runtime-variable operating parameters the data processing circuits 4 operate correctly and substantially without error. When operating outside of this typical-case range but inside the specified range of permitted values for the run-time variable operating parameters, then the error detection and error repair circuit 6 operate to repair the errors which occur.

Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 1014, a non-delayed signal-capture element 1016, a delayed signal-capture element 1018 and a comparator 1024. The non-delayed signal-capture element 1016 captures an output from the processing logic 1014 at a non-delayed capture time. At a later delayed capture time, the delayed signal-capture element 1018 also captures a value from the processing logic 1014. An error detection circuit 1026 and error correction circuit 1028 detect and correct random errors in the delayed value and supplies an error-checked delayed value to the comparator 1024. The comparator 1024 compares the error-checked delayed value and the non-delayed value and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the error-checked delayed value.

Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 2, a non-delayed latch 4, a delayed latch 8 and a comparator 6. The non-delayed latch 4 captures an output from the processing logic 2 at a non-delayed capture time. At a later delayed capture time, the delayed latch 8 also captures a value from the processing logic 2. The comparator 6 compares these values and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the delayed value. The non-delayed value is passed to the subsequent processing stage immediately following its capture and accordingly error recovery mechanisms are used to suppress the erroneous processing which has occurred by the subsequent processing stages, such as gating the clock and allowing the correct signal values to propagate through the subsequent processing logic before restarting the clock.

Abstract: A method for detecting microprocessor hardware faults includes sending at least one input signal to a logic block within the microprocessor, collecting an output response to the input signal from the logic block, and determining whether the output response matches an expected output response of the logic block.

Abstract: A state matcher for a logic circuit may detect at least one of a buggy state of the logic circuit, a precursor to a buggy state of the logic circuit and a verified state of the logic circuit based on a plurality of signal values indicative of a state of the logic circuit. A recovery controller for a microprocessor may reconfigure the microprocessor to a trusted feature mode in response to receiving a signal indicating that the microprocessor is in a predefined state and operate the microprocessor in the trusted feature mode for a predetermined period of time.

Abstract: A data processing apparatus and method are provided for recovering from errors in the data processing apparatus. The data processing apparatus comprises processing logic operable to perform a data processing operation, and a plurality of sampling circuits, each sampling circuit being located at a predetermined point in the processing logic and operable to sample a value of an associated digital signal generated by the processing logic at that predetermined point. Each of the sampling circuits includes a backup latch for storing a backup copy of the associated digital signal value, and at least one of the sampling circuits is operable to temporally sample the value of the associated digital signal at a first time and at at least one later time, and to store as a backup copy a selected one of the sampled values representing a correct value.

Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 1014, a non-delayed signal-capture element 1016, a delayed signal-capture element 1018 and a comparator 1024. The non-delayed signal-capture element 1016 captures an output from the processing logic 1014 at a non-delayed capture time. At a later delayed capture time, the delayed signal-capture element 1018 also captures a value from the processing logic 1014. An error detection circuit 1026 and error correction circuit 1028 detect and correct random errors in the delayed value and supplies an error-checked delayed value to the comparator 1024. The comparator 1024 compares the error-checked delayed value and the non-delayed value and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the error-checked delayed value.

Abstract: An integrated circuit having a plurality of processing stages includes a low power mode controller operable to control the integrated circuit to switch between an operational mode and a standby mode. At least one of the processing stages has a non-delayed latch to capture a non-delayed value of an output signal from that processing stage and a delayed latch operable during the operational mode to capture a delayed value of the same signal. A difference between these two captured signals is indicative of the processing operation not being completed at the time the non-delayed signal was captured. The delayed latch is operable during the standby mode to retain the signal it captured whilst the non-delayed latch is powered down and loses its value. The delayed latch is formed to have a lower power consumption than the non-delayed latch.

Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 2, a non-delayed latch 4, a delayed latch 8 and a comparator 6. The non-delayed latch 4 captures an output from the processing logic 2 at a non-delayed capture time. At a later delayed capture time, the delayed latch 8 also captures a value from the processing logic 2. The comparator 6 compares these values and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the delayed value. The non-delayed value is passed to the subsequent processing stage immediately following its capture and accordingly error recovery mechanisms are used to suppress the erroneous processing which has occurred by the subsequent processing stages, such as gating the clock and allowing the correct signal values to propagate through the subsequent processing logic before restarting the clock.

Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 1014, a non-delayed signal-capture element 1016, a delayed signal-capture element 1018 and a comparator 1024. The non-delayed signal-capture element 1016 captures an output from the processing logic 1014 at a non-delayed capture time. At a later delayed capture time, the delayed signal-capture element 1018 also captures a value from the processing logic 1014. An error detection circuit 1026 and error correction circuit 1028 detect and correct random errors in the delayed value and supplies an error-checked delayed value to the comparator 1024. The comparator 1024 compares the error-checked delayed value and the non-delayed value and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the error-checked delayed value.

Abstract: There is provided a memory for storing data comprising: a fast data reading mechanism operable to read a data value from said memory to generate a fast read result that is output from said memory for further processing; a slow data reading mechanism operable to read said data value from said memory to generate a slow read result available after said fast read result has been output for further processing, said slow data reading mechanism being less prone to error in reading said data value than said fast data reading mechanism; a comparator operable to compare said fast read result and said slow read result to detect if said fast read result differs from said slow read result; and error repair logic operable if said comparator detects that said fast read result differs from said slow read result to suppress said further processing using said fast read result, to output said slow read result in place of said fast read result and to restart said further processing based upon said slow read result.

Abstract: There is provided a memory for storing data comprising: a fast data reading mechanism operable to read a data value from said memory to generate a fast read result that is output from said memory for further processing; a slow data reading mechanism operable to read said data value from said memory to generate a slow read result available after said fast read result has been output for further processing, said slow data reading mechanism being less prone to error in reading said data value than said fast data reading mechanism a comparator operable to compare said fast read result and said slow read result to detect if said fast read result differs from said slow read result; and error repair logic operable if said comparator detects that said, fast read result differs from said slow read result to suppress said further processing using said fast read result, to output said slow read result in place of said fast read result and to restart said further processing based upon said slow read result.

Abstract: There is provided an integrated circuit comprising:

Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 1014, a non-delayed signal-capture element 1016, a delayed signal-capture element 1018 and a comparator 1024. The non-delayed signal-capture element 1016 captures an output from the processing logic 1014 at a non-delayed capture time. At a later delayed capture time, the delayed signal-capture element 1018 also captures a value from the processing logic 1014. An error detection circuit 1026 and error correction circuit 1028 detect and correct random errors in the delayed value and supplies an error-checked delayed value to the comparator 1024. The comparator 1024 compares the error-checked delayed value and the non-delayed value and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the error-checked delayed value.

Abstract: There is provided a memory for storing data comprising:

Abstract: An integrated circuit includes a plurality of processing stages each including processing logic 2, a non-delayed latch 4, a delayed latch 8 and a comparator 6. The non-delayed latch 4 captures an output from the processing logic 2 at a non-delayed capture time. At a later delayed capture time, the delayed latch 8 also captures a value from the processing logic 2. The comparator 6 compares these values and if they are not equal this indicates that the non-delayed value was captured too soon and should be replaced by the delayed value. The non-delayed value is passed to the subsequent processing stage immediately following its capture and accordingly error recovery mechanisms are used to suppress the erroneous processing which has occurred by the subsequent processing stages, such as gating the clock and allowing the correct signal values to propagate through the subsequent processing logic before restarting the clock.

Abstract: A method for detecting memory access errors which occur while executing a computer program. Spatial and temporal attributes are provided for a data object and these attributes are associated with each pointer to that data object. On a dereference to a pointer, a memory access check is performed which determines (a) whether the dereference falls outside the address range within which valid accesses may be made to the data object, and (b) whether the dereference falls outside the time period within which valid accesses may be made to the data object. If the dereference falls outside the valid address range, a spatial error is flagged. If the dereference falls outside the valid time period, a temporal error is flagged. In addition, a method is described for converting a preexisting source-language program file into a safe program and a method is described for optimizing memory-access checks.