Arm Limited

James Ian McNiven

Donald Kenneth Felton

Krisztian Flautner

David Hennah Mansell

Daniel Kershaw

Catalin Theodor Marinas

Robert John Brown

Daniel Luke Kefford

Adrian Mark Peirson

A data processing apparatus and a method of indicating operation of a data processor within a secure domain. The apparatus comprising a display for displaying data; a processor operable in a secure domain, said processor when operating in said secure domain having access to a user specific image; wherein said processor is operable to indicate operation within said secure domain by displaying said user specific image on at least a portion of said display when operating within said secure domain.

Secure operation indicator

A handheld devicegenerates a verification image to indicate that the device is operating in a secure domain. The verification image is generated in dependence upon secure data stored within a secure regionof a memoryand user input data captured from a user input device. The secure data may be data defining a three-dimensional object. The user image data may be captured from accelerometersdefining a viewpoint of the secret three-dimensional object.

Display of a verification image to confirm security

A data processing apparatus and method are provided for controlling access to registers. The data processing apparatus comprises a processing unit for performing data processing operations on data values, the processing unit having a plurality of modes of operation. A plurality of registers are provided for storing data values for access by the processing unit, with a subset of those registers being mode specific registers. Each mode specific register is used by the processing unit when operating in an associated mode of operation. The processing unit is switchable between a plurality of contexts, the data values stored in the plurality of registers being dependent on a current context of the processing unit. The processing unit performs a switch operation to switch from the current context to a new context, during which the data values in the registers are updated having regard to the new context. A control register is provided which, for at least one mode of operation having at least one mode specific register associated therewith, has an access field which is programmable by the processing unit when operating in a predetermined mode of operation. When the access field is set, the processing unit is selectively denied access to the associated at least one mode specific register, whereby updating of the data values in the associated at least one mode specific register is avoided during the switch operation. This significantly increases the speed of the switch operation.

Data processing apparatus and method for controlling access to registers

Power management control software including power management policies is provided with those policies divided into observation codeand response code. When predetermined execution pointswithin the operating systemare reached registered observation codefor those execution pointsis triggered to be executed and serves to store event data within an event data store. At another time independent of the execution points, the response codeis executed to read the event data from the event data storeand generate power control predictions and control signals therefrom.

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Ely, United Kingdom

James Ian McNiven