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US 7,657,694 B2Granted
Handling access requests in a data processing apparatus
AssigneeArm Limited
InventorsDavid Hennah Mansell, Stuart David Biles, Stephen John Hill
Life of this patent
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AssigneeArm Limited
InventorsDavid Hennah Mansell, Stuart David Biles, Stephen John Hill
Estimating the term…
A data processing apparatus is provided comprising processing logic for issuing access requests when access to data is required, with each access request specifying a memory address associated with the data the subject of the access request. Access control logic is used to perform an access control operation to check for each access request whether the specified memory address is accessible by the processing logic. Further, a table is provided having a plurality of entries, each entry identifying an address range and an associated action. On occurrence of one or more predetermined events, the access control logic references the table to determine whether the specified address is within the address range identified by an entry of the table. If so, the associated action specified in that entry is invoked, whereas otherwise the access control logic causes any action indicated by the access control operation to be performed. This provides a particularly efficient mechanism for handling access requests in a variety of situations, for example within a virtualization environment where the access requests are directed to virtual devices implemented by hypervisor software.
A data processing apparatus comprising:
A method of handling access requests in a data processing apparatus comprising processing circuitry for issuing access requests when access to data is required, each access request specifying a memory address associated with the data the subject of the access request, and access control circuitry for performing an access control operation to check for each access request whether the specified memory address is accessible by the processing logic, the method comprising the steps of:
Dependencies are inferred from the claim text.