EP0087956A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
System for controlling key storage unit
Assignee: Fujitsu Ltd
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Filing: 1983-02-25
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Granted: —
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Expires: 2003-02-25
Abstract
Abstract In a system for controlling a key storage unit in a data processing apparatus, a data processing apparatus comprising a main storage unit, a key storage unit for storing a main storage protection key corresponding to each unit block of the main storage unit, at least one processing unit, a main storage control unit, and a key storage control unit, the access request for the key storage unit is registered in the key queue of the key-storage control unit. The same access request for the key storage unit is prevented from being repeated many times.
Inventors
- 👤 Takashi Chiba
- 👤 Satoru Koga
- 👤 Minji Senda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 08:31
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/14; G06F12/1458; G06F12/1466
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
383 words
A system for controlling a key storage unit in a data processing apparatus; said data processing apparatus comprising a main storage unit; a key storage unit for storing a main storage protection key, a reference bit, and a change bit corresponding to each unit block of said main storage unit; at least one processing unit, said processing unit producing an access request for said main storage unit; a main storage control unit for processing said access request for said main storage unit; and a key storage control unit for controlling the access to said key storage unit; said main storage control unit also producing an access request for said key storage unit to change said reference bit and said change bit in said key storage unit corresponding to the accessed unit block of said main storage unit and supplying said access request for said key storage unit to said key storage control unit every time said main storage control unit accesses said main storage unit in response to said access request for said main storage unit supplied from said processing unit; said key storage control unit comprising a key queue for holding a plurality of said access requests for said key storage unit supplied from said main storage control unit temporarily, said key storage control unit registering each of said access requests for said key storage unit 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 out and processin -each of said access requests for said key storage unit registered in said key queue in order; said key storage control unit also comprising means for comparing the content of said access request for said key storage unit supplied from said main storage control unit with the content of each access request for said key storage unit registered in said key queue, and means for inhibiting said access request for said key storage unit supplied from said main storage control unit from being registered doubly in said key queue when the content of said access request for said key storage unit supplied from said main storage control unit is equal to the content of one of said access requests for-said key storage unit registered in said queue.
Claim 2
Independent Claim
383 words
A system for controlling a key storage unit in a data processing apparatus; said data processing apparatus comprising a main storage unit; a key storage unit for storing a main storage protection key, a reference bit, and a change bit corresponding to each unit block of said main storage unit; at least one processing unit, said processing unit producing an access request for said main storage unit; a main storage control unit for processing said access request for said main storage unit; and a key storage control unit for controlling the access to said key storage unit; said main storage control unit also producing an access request for said key storage unit to change said reference bit and said change bit in said key storage unit corresponding to the accessed unit block of said main storage unit and supplying said access request for said key storage unit to said key storage control unit every time said main storage control unit accesses said main storage unit in response to said access request for said main storage unit supplied from said processing unit; said key storage control unit comprising a key queue for holding a plurality of said access requests for said key storage unit supplied from said main storage control unit temporarily, said key storage control unit registering each of said access requests for said key storage unit 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 out and processin -each of said access requests for said key storage unit registered in said key queue in order; said key storage control unit also comprising means for comparing the content of said access request for said key storage unit supplied from said main storage control unit with the content of each access request for said key storage unit registered in said key queue, and means for inhibiting said access request for said key storage unit supplied from said main storage control unit from being registered doubly in said key queue when the content of said access request for said key storage unit supplied from said main storage control unit is equal to the content of one of said access requests for-said key storage unit registered in said queue.
Claim 3
Dependent Claim
36 words
A system for controlling a key storage unit as defined in claim 1; wherein said key queue has n unit memories, each of said unit memories including address data, a reference bit, and a change bit.
Claim 4
Dependent Claim
68 words
A system for controlling a key storage unit as defined in claim 2; wherein said key storage control unit comprises means for decoding said access request for said key storage unit supplied from said main storage control unit or said processing unit, and said decoding means judges whether said access request is a main storage data fetch command, a main storage data store command, or a key command.
Claim 5
Dependent Claim
69 words
A system for controlling a key storage unit as defined in claim 3; wherein as key commands, an insert storage key command for reading said main storage protection key in said key storage unit, a set storage key command for setting said main storage protection key in said key storage unit, and a reset reference bit command for resetting said reference bit in said key storage unit are processed.
Claim 6
Dependent Claim
101 words
A system for controlling a key storage unit as defined in claim 4; wherein when said reset reference bit command is supplied to said key storage control unit, the address portion of said reset reference command is compared with the address data of said access request registered in said key queue, and if said address portion is equal to said address data of one of said registered access requests, the reference bit of the corresponding address of said key storage unit is reset and the change bit of the same adress is changed as requested in said registered access request immediately.
References Cited (Backward Citations)
No citation records indexed.
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