Abstract: A processing pipeline may have first and second execution circuits having different performance or energy consumption characteristics. Instruction supply circuitry may support different instruction supply schemes with different energy consumption or performance characteristics. This can allow a further trade-off between performance and energy efficiency. Architectural state storage can be shared between the execute units to reduce the overhead of switching between the units. In a parallel execution mode, groups of instructions can be executed on both execute units in parallel.

Abstract: An apparatus 2 has a processing pipeline 4 supporting at least a first processing mode and a second processing mode with different energy consumption or performance characteristics. A storage structure 22, 30, 36, 50, 40, 64, 44 is accessible in both the first and second processing modes. When the second processing mode is selected, control circuitry 70 triggers a subset 102 of the entries of the storage structure to be placed in a power saving state.

Abstract: An apparatus and method are provided for triggering action performance. One example apparatus comprises memory access circuitry to retrieve a data value from a memory location of a memory. The apparatus further comprises action triggering circuitry to determine whether the data value is to be interpreted according to a first interpretation or a second interpretation and, when it is determined that the data value is to be interpreted according to the second interpretation, determine whether the data value defines an action to be performed. When it is determined that the data value defines an action to be performed, the action triggering circuitry is to trigger performance of the action.

Abstract: A data processing apparatus is provided, which includes storage circuitry comprising a plurality of lines, each of the plurality of lines comprising a data value. Access circuitry accesses a pair of the plurality of lines at a time, the pair of the plurality of lines comprising a further data value, distinct from the data value, and a plurality of error bits to detect or correct errors in the data value in each line in the pair of the plurality of lines.

Abstract: A data processing apparatus has processing circuitry for executing first software at a first privilege level and second software at a second privilege level higher than the first privilege level. Attributes may be set by the first and second software to indicate whether execution of the data access instruction can be interrupted. For a predetermined type of data access instruction for which the second attribute set by the second software specifies that the instruction can be interrupted, the instruction may be set as interruptable even if the first attribute set by the first software specifies that the execution of the instruction cannot be interrupted.

Abstract: Instructions have an opcode and at least one data operand, the opcode identifying a data processing operation to perform on the at least one data operand. For a register-provided-opcode instruction specifying at least one source register, at least part of the opcode is a register-provided opcode represented by a first portion of data stored in said at least one source register of the register-provided-opcode instruction, and the at least one data operand comprises data represented by a second portion of the data stored in the at least one source register. The register-provided opcode is used to select between different data processing operations supported for the same instruction encoding of the register-provided-opcode instruction.

Abstract: Exception control circuitry controls exception handling for processing circuitry. In response to an initial exception occurring when the processing circuitry is in a given exception level, the initial exception to be handled in a target exception level, the exception control circuitry stores exception control information to at least one exception control register associated with the target exception level, indicating at least one property of the initial exception or of processor state at a time the initial exception occurred. When at least one exception intercept configuration parameter stored in a configuration register indicates that exception interception is enabled, after storing the exception control information, and before the processing circuitry starts processing an exception handler for handling the initial exception in the target exception level, the exception control circuitry triggers a further exception to be handled in a predetermined exception level.

Abstract: An apparatus has first processing circuitry and second processing circuity. The second processing circuitry has at least one hardware mechanism providing a greater level of fault protection or fault detection than is provided for the first processing circuitry. Coherency control circuitry controls access to data from at least part of a shared address space by the first and second processing circuitry according to an asymmetric coherency protocol in which a local-only update of data in a local cache of the first processing circuitry is restricted in comparison to a local-only update of data in a local cache of the second processing circuitry.

Abstract: An apparatus and method are provided for performing data processing operations. The apparatus has processing circuitry for performing data processing operations configured to operate in a normal mode and a memory region management mode. A memory is used to store data accessed by the processing circuitry when performing the data processing operations. A memory region table is provided to define accessibility control information for each of a number of memory regions within the memory. An access control mechanism controls access to the memory in response to an access request issued by the processing circuitry, and a memory protection unit providing a bypass indication for one or more memory regions is referenced by the access control mechanism when the processing circuitry is in the memory region management mode.

Abstract: The execution of time intensive instructions can lead to critical events being responded to late or not being responded to at all. An information processing apparatus comprises processing circuitry (60) for executing instructions comprising one or more time intensive instructions and exception generating circuitry (100) for generating at least one exception for the processing circuitry. The processing circuitry maintains a control value (20) for indicating whether or not the time intensive instructions can be executed. When a time intensive instruction is encountered, if the control value indicates that time intensive instructions cannot be executed then a first exception triggers the processing circuitry to suppress execution of the time intensive instruction. Alternatively, if the control value indicates that time intensive instructions can be executed, then the time intensive instruction is executed.

Abstract: An apparatus and method are provided for executing debug instructions. The apparatus has processing circuitry for executing instructions fetched from memory, and a debug interface. The processing circuitry is responsive to a halt event to enter a halted mode where the processing circuitry stops executing the instructions fetched from memory, and instead is arranged to execute debug instructions received from a debugger via the debug interface. The processing circuitry is responsive to detection of a trigger condition when executing a given debug instruction to exit the halted mode transparently to the debugger, and to take an exception in order to execute exception handler code comprising a sequence of instructions fetched from memory. On return from the exception, the processing circuitry then re-enters the halted mode and performs any additional processing required to complete execution of the given debug instruction.

Abstract: Data processing apparatuses, methods of data processing, and non-transitory computer-readable media on which computer-readable code is stored defining logical configurations of processing devices are disclosed. In an apparatus, fetch circuitry retrieves a sequence of instructions and execution circuitry performs data processing operations with respect to data values in a set of registers. An auxiliary execution circuitry interface and a coprocessor interface to provide a connection to a coprocessor outside the apparatus are provided.

Abstract: An apparatus comprises processing circuitry for processing program instructions according to a predetermined architecture defining a number of architectural registers accessible in response to the program instructions. A set of hardware registers is provided in hardware. A storage capacity of the set of hardware registers is insufficient for storing all the data associated with the architectural registers of the pre-determined architecture. Control circuitry is responsive to the program instructions to transfer data between the hardware registers and at least one register-emulating memory location in memory for storing data corresponding to the architectural registers of the architecture.

Abstract: Examples of the present disclosure relate to methods for controlling a display device. In one such example, data representing a result of an eyewear detection operation is obtained. Dependent on the obtained data, a control signal is outputted to adjust a display parameter of the display device. Performing the eyewear detection operation comprises receiving image data representing a user of the display device, and processing the image data using object recognition to determine whether or not the user is wearing eyewear of a predetermined type.

Abstract: A data processing system provides a branch forward instruction (BF) which has programmable parameters specifying a branch target address to be branched to and a branch point identifying a program instruction following the branch forward instruction which, when reached, is followed by a branch to the branch target address.

Abstract: A data processing system provides a loop-end instruction for use at the end of a program loop body specifying an address of a beginning instruction of said program loop body. Loop control circuitry (1000) serves to control repeated execution of the program loop body upon second and subsequent passes through the program loop body using loop control data provided by the loop-end instruction without requiring the loop-end instruction to be explicitly executed upon each pass.

Abstract: A processing pipeline may have first and second execution circuits having different performance or energy consumption characteristics. Instruction supply circuitry may support different instruction supply schemes with different energy consumption or performance characteristics. This can allow a further trade-off between performance and energy efficiency. Architectural state storage can be shared between the execute units to reduce the overhead of switching between the units. In a parallel execution mode, groups of instructions can be executed on both execute units in parallel.

Abstract: Apparatus for processing data is provided with fetch circuitry for fetching program instructions for execution from one or more active threads of instructions having respective program counter values. Pipeline circuitry has a first operating mode and a second operating mode. Mode switching circuitry switches the pipeline circuitry, between the first operating mode and the second operating mode in dependence upon a number of active threads of program instructions having program instructions available to be executed. The first operating mode has a lower average energy consumption per instruction executed than the second operating mode and the second operating mode has a higher average rate of instruction execution for a single thread than the first operating mode. The first operating mode may utilise a barrel processing pipeline to perform interleaved multiple thread processing. The second operating mode may utilise an out-of-order processing pipeline for performing out-of-order processing.

Abstract: An apparatus comprises: selection circuitry to select the two most preferred items from a set of items having ranking information indicative of an order of preference for the set of items. The selection circuitry comprises at least one selection node circuit, each selection node circuit to receive as inputs an indication of a first pair of items and a second pair of items among the set of items, and comprises first selection circuitry and second selection circuitry. The first selection circuitry to first selection circuitry to select as a first selected item a most preferred one of: a most preferred ranked item of the first pair, and a least preferred item of the second pair. The second selection circuitry to select as a second selected item a most preferred one of: a least preferred item of the first pair, and a most preferred item of the second pair.

Abstract: Examples of the present disclosure relate to methods for controlling a display device. In one such example, data representing a result of an eyewear detection operation is obtained. Dependent on the obtained data, a control signal is outputted to adjust a display parameter of the display device. Performing the eyewear detection operation comprises receiving image data representing a user of the display device, and processing the image data using object recognition to determine whether or not the user is wearing eyewear of a predetermined type.