Patent ID: 7610464

Claim:
An I/O access control apparatus, comprising: a command receiver which receives, from an external access requesting entity, a command for controlling data in a memory space of a processor, together with address information used to specify an address to be accessed and ID information used to identify the access requesting entity; an access decision unit which determines whether access of the access requesting entity to an address specified by the address information is permitted or not, by referring to an access permission/denial determination table that associates an address in the memory space with ID information on an access requesting entity which is to be permitted to access a region specified by the address; and an access processing unit which executes access of the access requesting entity to the memory space, on the condition that the access has been permitted by said access decision unit, wherein said access decision unit determines, per page which is a unit of basic management in the memory space, whether access of the access requesting entity is permitted or not, and wherein in a case where plurality of access requesting entities transmit commands to access different pages, said access processing unit is capable of executing accesses to the different pages by the plurality of access requesting entities parallely in time.