Arm Limited

Apical Limited

Paul Stanley Hughes

Andrew Christopher Rose

Antony John Penton

Alex James Waugh

Robert Gwilym Dimond

Eric Biscondi

Mario Torrecillas Rodriguez

Yew Keong Chong

Simon John Craske

Stuart David Biles

Gus Wai-Yan Yeung

Jason Parker

Ian Rudolf Bratt

Simon Andrew Ford

Vladimir Vasekin

Michael Andrew Campbell

Alexander Eugene Chalfin

Damian Piotr Modrzyk

Richard Slobodnik

Frank David Frederick

Paul Darren Hoxey

Metin Gokhan Ünal

Alex Kornienko

Christopher Edwin Wrigley

Eric Kunze

Gary Robert Waggoner

Richard York

Brandon Michael Backlund

Jonathan Adam Lawton

A display controllerin a data processing system includes a timewarp module (transformation circuitry)that is operable to perform timewarp processing of a rendered framegenerated by a graphics processor (GPU)for provision to a display panel. The timewarp module (transformation circuitry)operates to transform an input surfaceread by the display controllerbased on received view orientation data to provide an appropriately 'timewarped' transformed version of the input surface as an output transformed surface for display on the display

Data processing systems

A data processing system and method of data processing are provided. The system comprises first and second data processing agents and data storage shared coherently between the both data processing agents to store a message data structure to provide a message channel between them. A further data storage is accessible to both data processing agents to store message channel metadata, which provides message status information for the message channel. The message channel metadata is one of a plurality of message channel metadata types defined for a corresponding plurality of message channel types between the first and second data processing agents, and at least one of the first and second data processing agents is responsive to an initialization trigger to establish the message channel with a selected message channel type.

Message passing in a data processing system

A data processing system and a method of data processing are provided. The system comprises a first data processing agent, a second data processing agent, and a third data processing agent. Each of the second and third data processing agents have access to one or more caches. A messaging mechanism conveys a message from the first data processing agent to one of the second and third data processing agents specified as a message destination agent in the message. A stashing manager monitors the messaging mechanism and selectively causes data associated with the message to be cached for access by the message destination agent in a cache of the one or more caches in dependence on at least one parameter associated with the message and at least one stashing control parameter defined for a link from the first data processing agent to the message destination agent.

Cache stashing in a data processing system

A cache to provide data caching in response to data access requests from at least one system device, and a method operating such a cache, are provided. Allocation control circuitry of the cache is responsive to a cache miss to allocate an entry of the multiple entries in the data caching storage circuitry in dependence on a cache allocation policy. Quality-of-service monitoring circuitry is responsive to a quality-of-service indication to modify the cache allocation policy with respect to allocation of the entry for the requested data item. The behaviour of the cache, in particular regarding allocation and eviction, can therefore be modified in order to seek to maintain a desired quality-of-service for the system in which the cache is found.

Cache allocation based on quality-of-service monitoring

A data processing apparatus and method are provided for handling hard errors occurring in a cache of the data processing apparatus. Cache location avoid storage is provided having at least one record, with each record being used to store a cache line identifier identifying a specific cache line. On detection of an error condition, one of the records in the cache location avoid storage is allocated to store the cache line identifier for the specific cache line associated with the entry for which the error condition was detected. A clean and invalidate operation is performed in respect of the specific cache line, and the access request is then re-performed. Cache access circuitry is arranged to exclude any specific cache line identified in the cache location avoid storage from a lookup procedure.

Handling of hard errors in a cache of a data processing apparatus

A counting circuit for a data processing apparatus has a normal mode in which a main counter increments the time count value in response to edges of a main clock signal, and a power saving mode in which the main clock signal is disabled and a further clock counter counts elapsed edges of a further clock signal having a lower frequency than the main clock signal. On switching to power saving mode, a reference time count value of the main counter is captured at a timing triggered by an edge of the further clock signal. On switching back to normal mode, an expected time count value from the main counter is calculated based on the captured reference value and the counted number of elapsed edges during the power saving mode, and the main counter is restarted at a timing triggered by another edge of the further clock signal.

Data processing apparatus and method for maintaining a time count value in normal and power saving modes of operation

An integrated circuit includes memory units and at least one memory test module, each module includes one associated memory unit, a set of test registers therefor, and a test engine configured to perform a test operation on that associated memory unit. A transaction interface of the memory test module receives a transaction specifying a register access operation and providing a first address portion having encodings allowing individual memory units as well as groups of memory units to be identified, and a second address portion identifying one of the test registers within the set to be an accessed register. Decode circuitry, within each memory test module and responsive to the transaction, is configured to selectively perform the register access operation if it is determined that the memory test module includes a set of test registers associated with a memory unit.

Integrated circuit and method for testing memory on the integrated circuit

A data processing apparatus is provided comprising processing circuitry for performing data processing operations, a set associative storage device for storing data values for access by the processing circuitry when performing data processing operations, error detection circuitry for performing, for each access to the storage device, an error detection operation on the data value accessed, and maintenance circuitry associated with the storage device for performing one or more maintenance operations. The processing circuitry is arranged to issue an error detection maintenance request to the maintenance circuitry specifying at least one specific physical location within the storage device, and the maintenance circuitry is responsive to the error detection maintenance request to perform at least one dummy access to the at least one specific physical location within the storage device and to provide the processing circuitry with error status information derived from the error detection operation performed by the error detection circuitry in respect of said at least one dummy access.

Error correction in a set associative storage device

A data processing apparatus comprises a circuit block to be tested, and a plurality of scan chains, each scan chain providing a mechanism for providing input test data to, and receiving output test data from, at least a portion of the circuit block during a test mode of operation. Configurable decompression circuitry is provided for supporting a plurality of decompression schemes associated with more than one test generation tool, and configuration circuitry is responsive to a configuration stimulus to configure the configurable decompression circuitry to implement a selected decompression scheme. Thereafter, on receipt of compressed input test data, the configurable decompression circuitry applies the selected decompression scheme to the compressed input test data to produce the input test data to be provided to the plurality of scan chains. Configurable compression circuitry can also be provided in a similar manner, with the configuration stimulus being used to configure the configurable compression circuitry to implement a selected compression scheme to be applied to the output test data in order to produce compressed output test data to be issued from an output interface. Such a mechanism provides a particularly flexible approach for supporting compression and decompression schemes in association with the data input to, and output from, the plurality of scan chains.

Data processing apparatus and method for testing a circuit block using scan chains

A data processing apparatus is provided in which a processing unit, by means of a read access request, accesses a storage device which stores data values and error data associated with those data values. When the processing unit accesses a data value in the storage device, error detection circuitry detects if an error is present in that data value and, if necessary, error correction circuitry corrects the read data value. An error cache having at least one entry stores corrected replacement data values, a corrected data value being allocated into an entry of the error cache for every corrected data value that is generated, and the read access request is re-performed. Replacement data values are read from the error cache in preference to data values stored in the storage device. This ensures that the retry mechanism will succeed irrespective of whether the error was a soft error or a hard error. Thus, if any hard errors do occur during normal operation of the storage device, they can effectively be temporarily corrected through use of the error cache to ensure that the retry mechanism proceeds correctly.

Apparatus and method for error correction of data values in a storage device

A memory is disclosed comprising: a storage array for storing data; and access circuitry for transmitting data to and from the storage array. The access circuitry forms a data path for inputting and outputting data to the storage array. The access circuitry comprises a latch configured to latch in response to a first phase of a first clock signal and a further latch configured to latch in response to a second phase of a second clock signal, the further latch comprises an output latch for outputting the data from the storage array, and the first and second clock signals are synchronized with each other. The memory further comprises: a multiplexer, a scan input and a scan enable input, the multiplexer being responsive to an asserted scan enable signal at the scan enable input to form a scan path comprising the latch and the further latch connected together to form a master slave flip flop, such that scan data input at the scan input passes through the master slave flip flop and not through the storage array while the scan enable signal is asserted and is output by the output latch.

Supporting scan functions within memories

This application discloses a data processing apparatus comprising: at least one memory; processing logic operable to perform data processing operations on data and operable to access said at least one memory; and memory testing logic operable to perform a transparent algorithm testing routine on said at least one memory, said data processing apparatus impeding said processing logic from accessing said at least one memory while said memory testing logic is performing said testing routine; wherein said processing logic and said memory testing logic are operable to detect a system event, said memory testing logic being operable when performing said testing routine to respond to detection of said system event by stopping said testing routine and restoring said at least one memory to an initial state, said initial state being a state it was in immediately prior to commencement of said testing routine, whereupon said data processing apparatus is operable to allow said processing logic to access said at least one memory.

Memory testing

A data processing apparatus comprising a plurality of data processors, each data processor comprising: first logic operable in a first clock domain and further logic operable in a second clock domain, said first and second clock domains being asynchronous with each other; a synchronizer operable to synchronize a signal processed by said first logic to produce a signal synchronized to said second clock domain; a synchronized signal output operable to export from said data processor said synchronized signal output from said synchronizer; and a signal input operable to import a signal to said data processor, said data processor being operable to route said imported signal to said further logic; wherein said plurality of data processors are arranged to operate in parallel with each other and said data processing apparatus further comprises: combining logic arranged to receive said exported synchronized signals from each of said plurality of data processors and to combine said exported synchronized signals to produce a resultant signal, said resultant signal being routed to each of said signal inputs of said plurality of data processors.

Synchronisation of signals between asynchronous logic

An integrated circuit and method for testing memory on that integrated circuit includes processing logic operable to perform data processing operations on data, and a number of memory units operable to store data for access by the processing logic. A memory test controller is also provided for executing test events in order to seek to detect any memory defects in the number of memory units. The controller includes a storage operable to store event defining information for each of a plurality of test events forming a sequence of test events to be executed, and an interface which, during a single programming operation, receives the event defining information for each of the plurality of test events and causes that event defining information to be stored in the storage. Event processing logic within the controller is then operable, following the single programming operation, to execute the sequence of test events.

Growing community of inventors

Cambridge, United Kingdom

Paul Stanley Hughes