Programmable Mapping of External Requestors to Privilege Classes for Access Protection

摘要

A memory management and protection system that manages memory access requests from a number of requestors. Memory accesses are allowed or disallowed based on the privilege level of the requestor, based on a Privilege Identifier that accompanies each memory access request. An extended memory controller selects the appropriate set of segment registers based on the Privilege Identifier to insure that the request is compared to and translated by the segment register associated with the master originating the request. A set of mapping registers allow flexible mapping of each Privilege Identifier to the appropriate access permission.