| 摘要 |
PURPOSE:To ensure the fine control for sharing a virtual address space with no conflict by providing a type field containing plural flags, an address field and a protection field. CONSTITUTION:A type field (Type) consists of a flag RA showing whether the restorage is needed or not, a flag US which designates a space in a restorage mode, and a flag PM which designates use or non-use of the protection information on a restoring destination. While an address field (Addr) includes a logical or physical address in response to the flag RA. Then a protection field (Prot) includes the protection information on read R, write W and execution E. Then it is decided based on the Type whether the restoration is carried out or not after a descriptor is read. If so, the Addr is defined as a logical address to perform conversion of address again. If not, the Addr is defined as a physical address and put into the access of a main memory. Thus a virtual address space can be finely shared and furthermore controlled with no conflict.
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