Abstract: A computing device incorporating repetitive side channel attack (SCA) countermeasures can include a timer circuit and a capacitive delay circuit that notifies of a potential repetitive-based attack by sending an activity-detected signal that can be used to initiate an appropriate countermeasure response. Additionally, or independently, a computing device incorporating repetitive SCA countermeasures can include at least one storage unit that can store an incoming input signal, at least one comparator to compare the incoming input signal with another signal and indicate a match, and a counter that increments upon the match. When the counter reaches a specified limit, a limit-exceeded signal can be sent to notify of a potential repetitive-based attack and initiate an appropriate countermeasure response.

Abstract: A computing device can include a comparator coupled to an I/O pin of the computing device; a storage unit coupled to the comparator; and a counter coupled to receive an output of the comparator, an output of the counter being coupled to a computation engine to provide a limit-exceeded signal to the computation engine, wherein the counter comprises a volatile counter and a nonvolatile storage, wherein the nonvolatile storage stores a bit for each top volatile count number of events identified by the volatile counter. The computing device can further include a backup power source coupled to the volatile counter; and readout circuitry and control logic coupled to the volatile counter and to the nonvolatile storage, the readout circuitry and control logic being configured to control operations of the volatile counter during an error event and determine a total number of events. The computing device can be a smart card.

Abstract: An apparatus comprises: processing circuitry to perform data processing; and an instruction decoder to control the processing circuitry to perform an anchored-data processing operation to generate an anchored-data element. The anchored-data element has an encoding including type information indicative of whether the anchored-data element represents: a portion of bits of a two's complement number, said portion of bits corresponding to a given range of significance representable using the anchored-data element; or a special value other than said portion of bits of a two's complement number.

Abstract: Apparatus and corresponding methods are disclosed relating to circuitry to perform an arithmetic operation on one or more input operands, where the circuitry is responsive to an equivalence of a result value of the arithmetic operation with at least one of the one or more input operands, when the one or more input operands are not an identity element for the arithmetic operation, to generate a signal indicative of the equivalence. Idempotency (between at least one input operand and the result value) is thus identified.

Abstract: An apparatus and method are provided for performing arithmetic operations to accumulate floating-point numbers. The apparatus comprises execution circuitry to perform arithmetic operations, and decoder circuitry to decode a sequence of instructions. A convert and accumulate instruction is provided, and the decoder circuitry is responsive to decoding the convert and accumulate instruction to generate one or more control signals to control the execution circuitry to convert at least one floating-point operand identified by the convert and accumulate instruction into a corresponding N-bit fixed-point operand having M fraction bits, where M is less than N and M is dependent on a format of the floating-point operand. The execution circuitry accumulates each corresponding N bit fixed-point operand and a P bit fixed-point operand identified by the convert and accumulate instruction in order to generate a P bit fixed-point result value, where P is greater than N and also has M fraction bits.

Abstract: Power is received from a first power signal a first of a plurality of charge stores. A second power signal is output from a second of the plurality of charge stores. The second power signal is isolated from the first power supply.

Abstract: Power is received from a first power signal at a first of a plurality of charge stores. A second power signal is output from a second of the plurality of charge stores. The second power signal is isolated from the first power supply.

Abstract: An apparatus and method are provided for processing input operand values. The apparatus has a set of vector data storage elements, each vector data storage element providing a plurality of sections for storing data values. A plurality of lanes are considered to be provided within the set of storage elements, where each lane comprises a corresponding section from each vector data storage element. Processing circuitry is arranged to perform an arithmetic operation on an input operand value comprising a plurality of portions, by performing an independent arithmetic operation on each of the plurality of portions, in order to produce a result value comprising a plurality of result portions. Storage circuitry is arranged to store the result value within a selected lane of the plurality of lanes, such that each result portion is stored in a different vector data storage element within the corresponding section for the selected lane.

Abstract: Apparatus and corresponding methods are disclosed relating to circuitry to perform an arithmetic operation on one or more input operands, where the circuitry is responsive to an equivalence of a result value of the arithmetic operation with at least one of the one or more input operands, when the one or more input operands are not an identity element for the arithmetic operation, to generate a signal indicative of the equivalence. Idempotency (between at least one input operand and the result value) is thus identified.

Abstract: An apparatus and method are provided for performing arithmetic operations to accumulate floating-point numbers. The apparatus comprises execution circuitry to perform arithmetic operations, and decoder circuitry to decode a sequence of instructions in order to generate control signals to control the arithmetic operations performed by the execution circuitry. A convert and accumulate instruction is provided, and the decoder circuitry is responsive to decoding such a convert and accumulate instruction within the sequence of instructions to generate one or more control signals to control the execution circuitry. In particular, the execution circuitry is responsive to such control signals to convert at least one floating-point operand identified by the convert and accumulate instruction into a corresponding N-bit fixed-point operand having M fraction bits, where M is less than N and M is dependent on a format of the floating-point operand.

Abstract: Apparatus and a corresponding method are disclosed relating to circuitry to perform an arithmetic operation on one or more input operands, where the circuitry is responsive to an equivalence of a result value of the arithmetic operation with at least one of the one or more input operands, when the one or more input operands are not an identity element for the arithmetic operation, to generate a signal indicative of the equivalence. Idempotency (between at least one input operand and the result value) is thus identified.

Abstract: Processing circuitry is provided to perform an overlap propagating operation on a first data value to generate a second data value, the first and second data values having a redundant representation representing a P-bit numeric value using an M-bit data value comprising a plurality of N-bit portions, where M>P>N. In the redundant representation, each N-bit portion other than a most significant N-bit portion includes a plurality of overlap bits having a same significance as a plurality of least significant bits of a following N-bit portion. Each N-bit portion of the second data value other than a least significant N-bit portion is generated by adding non-overlap bits of a corresponding N-bit portion of the first data value to the overlap bits of a preceding N-bit portion of the first data value. This provides a faster technique for reducing the chance of overflow during addition of the redundantly represented M-bit value.

Abstract: Apparatus and a corresponding method are disclosed relating to circuitry to perform an arithmetic operation on one or more input operands, where the circuitry is responsive to an equivalence of a result value of the arithmetic operation with at least one of the one or more input operands, when the one or more input operands are not an identity element for the arithmetic operation, to generate a signal indicative of the equivalence. Idempotency (between at least one input operand and the result value) is thus identified.

Abstract: A data processing system supports execution of program instructions having a rounding position input operand so as to generate control signals for controlling processing circuitry to process a floating point input operand with a significand value to generate an output result which depends upon a value from rounding the floating point input operand using a variable rounding point within the significand of the floating point input operand as specified by the rounding position input operand. In this way, processing operations having as inputs floating point operands and anchored number operands may be facilitated.

Abstract: An apparatus comprises processing circuitry to perform a conversion operation to convert a floating-point value to a vector comprising a plurality of data elements representing respective bit significance portions of a binary value corresponding to the floating-point value.

Abstract: An apparatus includes processing circuitry to perform one or more arithmetic operations for generating a result value based on at least one operand. For at least one arithmetic operation, the processing circuitry is responsive to programmable significance data indicative of a target significance for the result value, to generate the result value having the target significance. For example, this allows programmers to set a significance boundary for the arithmetic operation so that it is not necessary for the processing circuitry to calculate bit values having a significance outside the specified boundary, enabling a performance improvement.

Abstract: A data processing system supports vector operands with components representing different bit significance portions of an integer number. Processing circuitry performs a processing operation specified by a program instruction in dependence upon a number of components comprising the vector as specified by metadata for the vector.

Abstract: Processing circuitry performs a plurality of lanes of processing on respective data elements of at least one operand vector to generate corresponding result data elements of a result vector. The processing circuitry identifies lane position information for each lane of processing, the lane position information for a given lane identifying a relative position of the corresponding result data element to be generated by the given lane within a corresponding result data value spanning one or more result data elements of the result vector. The processing circuitry is configured to perform each lane of processing in dependence on the lane position information identified for that lane. This enables generation of results which are wider or narrower than the vector size supported in hardware.

Abstract: A redundant representation is provided where an M-bit value represents a P-bit numeric value using a plurality of N-bit portions, where M>P>N. An anchor value identifies the significance of bits of each N-bit, and within a group of at least two adjacent N-bit portions, two or more overlap bits of a lower N-bit portion of the group have a same significance as two or more least significant bits of at least one upper N-bit portion of the group. A plurality of operation circuit units can perform a plurality of independent N-bit operation in parallel, each N-bit operation comprising computing a function of corresponding N-bit portions of at least two M-bit operand values having the redundant representation to generate a corresponding N-bit portion of an M-bit result value having the redundant representation. This enables fast associative processing of relatively long M-bit values in the time taken for performing an N-bit operation.

Abstract: A data processing system performs processing operations upon input operand(s) having a programmable bit significance. Exception generating circuitry generates exception indications representing exceptions such as overflow, underflow and inexact in respect of a result value having the programmable bit significance.