PURPOSE: To attain the fine protection of storage within a virtual storage and to avoid the reduction of the instruction executing efficiency, by executing an access when the access is allowed or producing an interruption if the access is inhibited when an instruction which gives an access to the virtual storage is executed.
CONSTITUTION: A storage protecting device consists of an instruction control unit 1, a storage control unit 2, an arithmetic unit 3 and a main storage 4. The unit 1 contains an instruction virtual address register 5 and a data virtual address register 6. The unit 2 contains an address converting circuit 7, a data key register 8, an instruction key register 9, a key comparator 10 and an interruption generating circuit 11. The storage 4 contains an address conversion table 12. The comparator 10 checks the matching of keys to make the unit 3 continue the instruction processing with the combination of keys to which accesses are allowed and to inform an interruption to the unit 3 with the combination of keys to which the accesses are inhibited respectively.
TAKAHASHI KIKUO
ONO MIE
YOSHIZUMI SEIICHI
