Patent ID: 7149862

Claim:
A data processing apparatus operable to control access to a slave device, the slave device having an address range associated therewith, the apparatus comprising: control storage programmable to define a partition identifying a secure region and a non-secure region in said address range, the data processing apparatus supporting a plurality of modes of operation including a secure mode, and the control storage being programmable only by software executing in said secure mode; a master device operable to issue an access request onto a bus, the access request identifying a sequence of addresses within said address range and including a control signal indicating whether the access request is a secure access request or a non-secure access request, the secure region only being accessible by a secure access request; and access control logic associated with the slave device, the access control logic being operable to receive the access request from the bus and an indication of the partition from the control storage and, if the access request is a non-secure access request, to prevent access to the secure region.