초록 ▼

A data processing apparatus includes at least one processing unit, a main storage unit, a main storage control unit, a key storage unit and a key storage control unit. The main storage unit is divided into blocks and the key storage unit stores main storage protection keys, each of which corresponds

A data processing apparatus includes at least one processing unit, a main storage unit, a main storage control unit, a key storage unit and a key storage control unit. The main storage unit is divided into blocks and the key storage unit stores main storage protection keys, each of which corresponds to one of the blocks of the main storage unit. Key storage access requests are received from a processing unit or the main storage control unit by the key storage control unit whenever data is to be read from or written to a block of main storage. The key storage control unit registers the key storage access requests in a key queue, prevents duplicate access requests from being registered, and processes the queued key storage access requests. The processing of key storage access requests includes updating the contents of the key storage unit to maintain a record of accesses to the main storage unit and controlling accesses to the main storage unit by permitting or denying access thereto.

대표청구항 ▼

A system for controlling a key storage unit in a data processing apparatus, comprising: a main storage unit having at least one block; a key storage unit for storing a main storage protection key, at least one reference bit, and at least one change bit for each block of said main storage unit; a pro

A system for controlling a key storage unit in a data processing apparatus, comprising: a main storage unit having at least one block; a key storage unit for storing a main storage protection key, at least one reference bit, and at least one change bit for each block of said main storage unit; a processing unit, said processing unit producing at least one access request for said main storage unit; a main storage control unit, operatively connected to said main storage unit and said processing unit, for processing the access request for said main storage unit and producing a key storage access request for said key storage unit, said key storage access request having address data and requesting a change in the reference bit and the change bit in said key storage unit, the reference bit and the change bit corresponding to the accessed block of said main storage, said main storage control unit supplying said key storage access request for said key storage unit every time said main storage control unit accesses said main storage unit in response to the access request for said main storage unit supplied from said processing unit; a key storage control unit, operatively connected to said processing unit and said main storage control unit, for controlling access to said key storage unit, comprising: a key queue, operatively connected to said main storage control unit and said key storage unit, for temporarily holding a plurality of said key storage access requests supplied from said main storage control unit, said key storage control unit registering each of said key storage access requests supplied from said main storage control unit into said key queue in order, and said key storage control unit, independent of the above-mentioned registering process, reading and processing each of said key storage access requests registered in said key queue in order; comparing means, operatively connected to said key queue and said main storage control unit, for comparing the content of said key storage access request supplied from said main storage control unit with the content of each key storage access request registered in said key queue; and inhibiting means, operatively connected to said comparing means and said key queue, for inhibiting said key storage access request supplied from said main storage control unit from being registered in said key queue when the content of said key storage access request supplied from said main storage control unit is equal to the content of one of said key storage access requests registered in said key queue.