Arm Limited

University of Michigan

David Michael Bull

Shidhartha Das

David Theodore Blaauw

Paul Nicholas Whatmough

Krisztian Flautner

Trevor N Mudge

Vladimir Vasekin

Todd Austin

Alexei Fedorov

James Edward Myers

Frederic Claude Marie Piry

Emre Özer

Emre Ozer

Peter Guy Middleton

Parameshwarappa Anand Kumar Savanth

Pranay Prabhat

Luca Scalabrino

Paul Darren Hoxey

David Walter Flynn

Andrew Christopher Rose

Daniel Kershaw

Guillaume Schon

David Anthony New

Anand Savanth

Sanghyun Park

Bal S Sandhu

Edgar Herbert Callaway, Jr

Robert Campbell Aitken

Sachin Satish Idgunji

Simon Andrew Ford

El Mehdi Boujamaa

Alastair David Reid

Ganesh Suryanarayan Dasika

David William Howard

Benoit Labbe

Mladen Wilder

Chiloda Ashan Senarath Pathirane

David John Gwilt

Adeline-Fleur Fleming

Mélanie Emanuelle Lucie Teyssier

Gary Campbell

Vincent Rezard

George Christopher Smart

Anton Antonov

In one particular implementation, a circuit includes: a flip flop; and an AND gate, where the circuit is configured to generate edge-triggered set and reset input signals. In another implementation, a method includes: providing, by a digital locked loop (DLL), a plurality of phase outputs; determining, by respective logic circuits, respective pulses to be selected for an output clock corresponding to each of the plurality phase outputs; shifting respective selection windows of the pulses such that each of the selection windows fully overlap the corresponding respective determined pulses; and selecting the pulses.

Circuits and methods for set and reset signals

Apparatus, method and code for fabrication of the apparatus, the apparatus comprising a cache providing a plurality of cache lines, each cache line storing a block of data; cache access control circuitry, responsive to an access request, to determine whether a hit condition is present in the cache; and cache configuration control circuitry to set, in response to a merging trigger event, merge indication state identifying multiple cache lines to be treated as a merged cache line to store multiple blocks of data, wherein when the merge indication state indicates that the given cache line is part of the merged cache line, the cache access control circuitry is responsive to detecting the hit condition to allow access to any of the data blocks stored in the multiple cache lines forming the merged cache line.

Treating multiple cache lines as a merged cache line to store multiple blocks of data

Apparatuses and methods of data processing are disclosed for processing circuitry having a pipeline of multiple stages. Value prediction storage circuitry holds value predictions, each associated with an instruction identifier. The value prediction storage circuitry performs look-ups and provides the processing circuitry with data value predictions. The processing circuitry speculatively issues a subsequent instruction into the pipeline by provisionally assuming that execution of a primary instruction will result in the generated data value prediction. Allocation of entries into the value prediction storage circuitry is based on a dynamic allocation policy, whereby likelihood of allocation into the value prediction storage circuitry of an data value prediction increases for an executed instruction when the executed instruction is associated with at least one empty processing stage in the pipeline.

Selecting instructions for a value predictor

An apparatus has processing circuitry for executing instructions and fetch circuitry for fetching the instructions for execution. When a branch instruction is encountered by the fetch circuitry, it determines subsequent instructions to be fetched in dependence on an initial branch direction prediction for the branch instruction made by branch prediction circuitry. Value prediction circuitry is used to maintain a predicted result value for one or more instructions, and dispatch circuitry maintains a record of pending instructions that have been fetched by the fetch circuitry and are awaiting execution by the processing circuitry, and selects pending instructions from the record for dispatch to the processing circuitry. When a given instruction whose predicted result value is maintained by the value prediction circuitry has a dependent instruction whose outcome is dependent on a result value of the given instruction, the dispatch circuitry nay be arranged to enable speculative execution of that dependent instruction using the predicted result value of the given instruction. Analysis circuitry is arranged, when the dependent instruction is the branch instruction, to detect a mispredict condition when an additional branch direction prediction for the branch instruction determined using the predicted result value for the given instruction is considered more accurate that the initial branch direction prediction, and the additional branch direction prediction differs to the initial branch direction prediction. On detection of the mispredict condition, a control signal is issued to indicate that the branch instruction has been mispredicted.

Detecting misprediction when an additional branch direction prediction determined using value prediction is considered more accurate than an initial branch direction prediction

A digital processor, method, and a non-transitory computer readable storage medium are described, and include a load pipeline operative to access a data content and convert the data content into a load result. The digital processor also includes a value prediction check circuit that is operative to access a speculative content, determine a predicted value from the speculative content, and determine a masked value by masking the data content with a data mask. The masked value is compared to the predicted value, and an action associated with the load result is commanded based upon the comparing of the masked value and the predicted value.

Method and apparatus for comparing predicated load value with masked load value

An apparatus and method are provided for using predicted result values. The apparatus has a processing unit that comprises processing circuitry for executing a sequence of instructions, and value prediction circuitry for identifying a predicted result value for at least one instruction. A result producing structure is provided that is responsive to a request issued from the processing unit when the processing circuitry is executing a first instruction, to produce a result value for the first instruction and return that result value to the processing unit. While waiting for the result value from the result producing structure, the processing circuitry can be arranged to speculatively execute at least one dependent instruction using a predicted result value for the first instruction as obtained from the value prediction circuitry. The request issued from the processing unit includes a signature value indicative of the predicted result value, and the result producing structure references the signature value in order to detect whether a mispredict condition exists indicating that the predicted result value differs from the result value. The apparatus further provides a mispredict signal transmission path via which the result producing structure, when the mispredict condition is detected, can assert a mispredict signal for receipt by the processing unit prior to the result value being available to the processing unit. Such an approach can reduce the misprediction penalty associated with using a mispredicted result value.

Apparatus and method for using predicted result values

An apparatus and method are provided for using predicted result values. The apparatus has processing circuitry for executing a sequence of instructions, and value prediction storage that comprises a plurality of entries, where each entry is used to identify a predicted result value for an instruction allocated to that entry. Dispatch circuitry maintains a record of pending instructions awaiting execution by the processing circuitry, and selects pending instructions from the record for dispatch to the processing circuitry for execution. The dispatch circuitry is arranged to enable at least one pending instruction to be speculatively executed by the processing circuitry using as a source operand a predicted result value provided by the value prediction storage. Allocation circuitry is arranged to apply a default allocation policy to identify a first instruction to be allocated an entry in the value prediction storage. However, the allocation circuitry is further responsive to a trigger condition to identify a dependent instruction whose result value will be dependent on the result value produced by executing the first instruction, and to then allocate an entry in the value prediction storage to store a predicted result value for the identified dependent instruction. Such an approach can enable performance improvements to be achieved through the use of predicted result values even in situations where the prediction accuracy of the predicted result value for the first instruction proves not to be that high, by instead enabling a predicted result value for the dependent instruction to be used to allow speculative execution of further dependent instructions.

Appratus and method for using predicted result values

An electronic device () has a clock path () for propagating a clock signal and a clock propagating element () on the clock path. An analogue element () coupled to the clock path () varies, in dependence on an analogue level of a first signal (), a switching delay for the clock propagating element () to trigger a transition of the clock signal. The first signal is a digitally sampled signal. This provides a mechanism for providing a fast reduction in clock frequency even if the first signal is a metastable signal, which is useful for avoiding errors causes by voltage drops.

Clock frequency reduction for an electronic device

An integrated circuit includes one or more portions having error detection and error correction circuits and which is operated with operating parameters giving finite non-zero error rate as well as one or more portions formed and operated to provide a zero error rate.

Error recovery within integrated circuit

A device comprises a coupling configured to couple signals to and from a communications path including at least a part of a human or animal body; a data transmitter coupled to the coupling and configured to transmit, from time to time, a data signal of at least a predetermined temporal duration via the communications path; and a data receiver coupled to the coupling and configured to detect the presence of a signal on the communications path at sets of one or more successive detection instances disposed between successive transmissions of the data signal by the data transmitter, the data receiver being configured so that the successive detection instances of a set are temporally separated by no more than the predetermined temporal duration; the device being configured to initiate a processing operation in response to a detection by the data receiver of the presence of a signal on the communications path.

Communications device and method

A transition detection circuit and method of operation of such a circuit are provided, the transition detection circuit having pulse generation circuitry to receive an input signal and to generate a pulse signal in response to a transition in the input signal, and pulse detection circuitry to assert an error signal on detection of the pulse signal generated by the pulse generation circuitry. The pulse generation circuitry has pulse control circuitry to control a property of the pulse signal dependent on a timing window indication signal. In particular, when the pulse signal is generated at least partly while the timing window indication signal is set, the pulse control circuitry controls the property of the pulse signal such that generated pulse signal is detected by the pulse detection circuitry. In contrast, when the pulse signal is entirely generated while the timing window indication signal is cleared, the pulse control circuitry controls the property of the pulse signal such that the generated pulse signal is undetected by the pulse detection circuitry. This gives rise to significant area and energy consumption savings, while still allowing reliable detection of timing errors.

Transition detection circuitry and method of detecting a transition of a signal occurring within a timing window

A storage bitcell comprising a first inverter cross-coupled with a second inverter, both the first and second inverter being in a path between a first potential and a second potential; wherein a first isolator is connected in the path between the first inverter and the first potential. The storage bitcell has particular application as Static Random-Access Memory (SRAM) circuitry.

Storage bitcell

A method, system and surface covering for enabling wireless detection of damage to a structure is disclosed. At least one array having a plurality of nodes are coupled to a surface covering, such as at least one of a wall, ceiling and floor covering for a least a portion of the structure. An electronic reader is operable to wirelessly interrogate the array and read return signals from nodes in the array. The return signals contain data representing an ID for corresponding responsive nodes in the array, and the returned IDs are extracted and compared to a plurality of IDs stored in a data store for nodes in any given array. A mismatch between the returned and stored IDs for the nodes in the array indicates a structural defect in a respective portion of the structure overlaid by the floor/wall covering.

Smart surface covering and structure having remotely interrogatable antenna node array for remote integrity checking

Storage bitcell with isolation

Growing community of inventors

Cambridge, United Kingdom

David Michael Bull