Patent ID: 7107377

Claim:
An information processing apparatus, comprising: a process part implementing an access to an address to be accessed having an access level; an access detector detecting whether the address accessed by the process part agrees or disagrees with an address whose access level is changed, said access detector including a gate adapted to receive output based on said detecting and based on whether an access control signal indicates an instruction fetch; and an access part receiving an output from the access detector and being capable of changing the access level registered at the access part when the access is detected by the access detector, said access level determining an area where access from a device to a source is allowed, said access part including: a level holding part outputting an access level which is pre-set at the address registered at the access part when the access to the address to be accessed is detected by the access detector, an access allowance setting part in which an access allowance address for every access level is set, and an access control part selecting the access allowance address which is set at the access allowance setting part and which corresponds to the access level output from the level holding part, and thereby the access by the process part is allowed when the designated address accessed by the process part agrees with the access allowance address.