A
control unit (300) comprising the following: a
control unit memory (120) with a configuration register (124) for defining an operating mode of the
control unit (300) and a lock register (122) for storing a lock indicator, wherein, immediately after
authorization information has been set during a
system initialization event, the lock indicator in the lock register (122) is set to a value indicating whether at least part of the
authorization information can be changed or not, and set up a controller (302) to: to receive a request for access to a first memory area of a memory (308) from a request device (306) separate from the control unit (300); in response to the request to access
authorization information, which contains a multitude of entries corresponding to different memory areas (110-1 to 110-n) of the memory (308), each entry of the multitude of entries comprising a multitude of indicators, the indicators comprising: a first indicator that can assume an
active value, representing an execution access mode in which instructions are retrieved from the respective memory area for execution, a second indicator that can assume an
active value representing a privileged access mode in which access to the respective memory area is permitted if the requester has a privileged level; and a third indicator representing a read or write mode on a memory area; and Based on the occurrence of the
system initialization event and according to the
metadata of the request and the authorization information, to determine whether access to the content in the first
storage area is allowed.