Patent ID: 7657694

Claim:
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; 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 circuitry; a memory for storing a table having a plurality of entries, each entry identifying an address range and an associated action; the access control circuitry being configured on occurrence of a determination by the access control circuitry that the specified memory address is not accessible by the processing circuitry to reference the table to determine whether the specified address is within the address range identified by an entry of the table; if the specified address is within the address range identified by an entry of the table, the access control circuitry being configured to cause the associated action specified in that entry to be invoked without generating an exception; and if the specified address is not within the address range identified by an entry of the table, the access control circuitry being configured to cause an exception to be generated.