Patent attributes
A data processing apparatus is provided, which is operable to access data values associated with a respective address values. The data processing apparatus has: a processor; a main memory having a secure data values region; a cache; and cache interface logic having data transaction logic and security determination logic. The data transaction logic receives from the processor a data access request for accessing data in cache. The data access request has an associated address value and a security attribute. If the security attribute indicates that the request is a non-secure data-access request, the security determination logic determines, via a data region allocation table, whether the request is associated with the secure data values region of main memory and the non-secure data access request is allowed to complete if it is not associated with the secure data region.