Nothing Special   »   [go: up one dir, main page]

JPS57195394A - Memory protection system by processor - Google Patents

Memory protection system by processor

Info

Publication number
JPS57195394A
JPS57195394A JP56078406A JP7840681A JPS57195394A JP S57195394 A JPS57195394 A JP S57195394A JP 56078406 A JP56078406 A JP 56078406A JP 7840681 A JP7840681 A JP 7840681A JP S57195394 A JPS57195394 A JP S57195394A
Authority
JP
Japan
Prior art keywords
signal
access
memory
information
processor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP56078406A
Other languages
Japanese (ja)
Inventor
Keizou Miyanaga
Takashi Katsukawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Original Assignee
Nippon Telegraph and Telephone Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Telegraph and Telephone Corp filed Critical Nippon Telegraph and Telephone Corp
Priority to JP56078406A priority Critical patent/JPS57195394A/en
Publication of JPS57195394A publication Critical patent/JPS57195394A/en
Pending legal-status Critical Current

Links

Landscapes

  • Storage Device Security (AREA)

Abstract

PURPOSE: To realize the hierarchy structure of programs and the separation of memory access ranges, and to achieve careful memory protection, by giving different priority levels to the programs.
CONSTITUTION: Priority information 4 outputted from a memory key register 1 is compared by a comparator 10 with priority information 8 from a protect key register 7, and section information 5 is compared by a comparator 11 with section information 9. A discriminating circuit 14 for discriminating whether access is allowed or not receives a priority information compaison signal 12, a section information comparison signal 13, and access limit information 6, and outputs a discrimination signal 15. An access error reporting circuit 16, once receiving a memory access signal 17, sends an interruption request signal 18 to a processor when the discrimination signal 15 shows an access error, and a write request signal 19 to a memory is inhibited by an NAND circuit 24.
COPYRIGHT: (C)1982,JPO&Japio
JP56078406A 1981-05-23 1981-05-23 Memory protection system by processor Pending JPS57195394A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56078406A JPS57195394A (en) 1981-05-23 1981-05-23 Memory protection system by processor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56078406A JPS57195394A (en) 1981-05-23 1981-05-23 Memory protection system by processor

Publications (1)

Publication Number Publication Date
JPS57195394A true JPS57195394A (en) 1982-12-01

Family

ID=13661137

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56078406A Pending JPS57195394A (en) 1981-05-23 1981-05-23 Memory protection system by processor

Country Status (1)

Country Link
JP (1) JPS57195394A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61195443A (en) * 1985-02-21 1986-08-29 セキュア・コンピューティング・コーポレーション Method of protecting system file in data processing system and data processing system
JPH0192856A (en) * 1987-07-01 1989-04-12 Digital Equip Corp <Dec> Apparatus and method for protecting main memory unit using access and defect logic signal

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55116155A (en) * 1979-02-28 1980-09-06 Hitachi Ltd Memory protective system
JPS5617452A (en) * 1979-07-23 1981-02-19 Fujitsu Ltd Ring protection system
JPS5679348A (en) * 1979-11-30 1981-06-29 Hitachi Ltd Memory protective system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55116155A (en) * 1979-02-28 1980-09-06 Hitachi Ltd Memory protective system
JPS5617452A (en) * 1979-07-23 1981-02-19 Fujitsu Ltd Ring protection system
JPS5679348A (en) * 1979-11-30 1981-06-29 Hitachi Ltd Memory protective system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61195443A (en) * 1985-02-21 1986-08-29 セキュア・コンピューティング・コーポレーション Method of protecting system file in data processing system and data processing system
JPH0192856A (en) * 1987-07-01 1989-04-12 Digital Equip Corp <Dec> Apparatus and method for protecting main memory unit using access and defect logic signal

Similar Documents

Publication Publication Date Title
JPS5574421A (en) Liquid level detector
US4747116A (en) Sync signal detecting device
JPS5766515A (en) Memory address control system
JPS57195394A (en) Memory protection system by processor
JPS5792411A (en) Pcm signal processor
KR940006014A (en) Timer circuit with comparator
JPS6412348A (en) Buffer control system
JPS5533288A (en) Hysteresis recording control system of multi-processor system
JPS6450148A (en) Memory resetting circuit
JPS5326632A (en) Common memory control unit
JPS5437432A (en) Error detector of memory device
JPS57120300A (en) Program protection system
JPS5480050A (en) Data processor
JPS54106132A (en) Buffer memory access process system
JPS5350625A (en) Error detecting system
JPS5617442A (en) Parity error processing system
JPS54116969A (en) Time limit device
JPS57132258A (en) Readout system for plural word data
JPS54129948A (en) Data processor
JPS6474644A (en) Data processor for memory
JPS5326630A (en) Memory test system
JPS61216059A (en) System for protecting storage data
JPS5494840A (en) Information processor
JPS5525155A (en) Memory access system
JPS5621250A (en) Instruction retrial system