JPS5617452A - Ring protection system - Google Patents

Ring protection system

Info

Publication number
JPS5617452A
JPS5617452A JP9352079A JP9352079A JPS5617452A JP S5617452 A JPS5617452 A JP S5617452A JP 9352079 A JP9352079 A JP 9352079A JP 9352079 A JP9352079 A JP 9352079A JP S5617452 A JPS5617452 A JP S5617452A
Authority
JP
Japan
Prior art keywords
output
generates
user
comp
limit
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
JP9352079A
Other languages
Japanese (ja)
Inventor
Hiroyuki Koarai
Nobuyuki Baba
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.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP9352079A priority Critical patent/JPS5617452A/en
Publication of JPS5617452A publication Critical patent/JPS5617452A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To prevent a user program from destroying a program in a system space by mistake by employing a limit register system for a ring protection system and then by making it effective only in a user's area.
CONSTITUTION: In the 1st and 2nd limit registers LR0 and LR1, upper limit and lower limit segment numbers SN0 and SN1 of the user's area of a user program in run mode at that time are written, and comparators COMP1 and COMP2 receive those segment number at one-side input terminals and segment number SN of address LA, to which the next access is attained, at the other-side input terminals. Comparator COMP1 generates no output when SN0>SN and comparator COMP2 generates no output when SN>SN1. Therefore, while SN0<SN<SN1, OR gate OG generates no output, but while not, an access inhibition output is sent out of OR gate OG.
COPYRIGHT: (C)1981,JPO&Japio
JP9352079A 1979-07-23 1979-07-23 Ring protection system Pending JPS5617452A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9352079A JPS5617452A (en) 1979-07-23 1979-07-23 Ring protection system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9352079A JPS5617452A (en) 1979-07-23 1979-07-23 Ring protection system

Publications (1)

Publication Number Publication Date
JPS5617452A true JPS5617452A (en) 1981-02-19

Family

ID=14084599

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9352079A Pending JPS5617452A (en) 1979-07-23 1979-07-23 Ring protection system

Country Status (1)

Country Link
JP (1) JPS5617452A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57195394A (en) * 1981-05-23 1982-12-01 Nippon Telegr & Teleph Corp <Ntt> Memory protection system by processor
JPS60120451A (en) * 1983-12-05 1985-06-27 Fujitsu Ltd Memory protection in unit of word

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57195394A (en) * 1981-05-23 1982-12-01 Nippon Telegr & Teleph Corp <Ntt> Memory protection system by processor
JPS60120451A (en) * 1983-12-05 1985-06-27 Fujitsu Ltd Memory protection in unit of word

Similar Documents

Publication Publication Date Title
JPS5621240A (en) Information processor
JPS5242334A (en) Computer
JPS5617452A (en) Ring protection system
JPS5282149A (en) Instruction address control system
JPS5386537A (en) Data transfer system
JPS5235929A (en) Program reservation system
JPS5392638A (en) Information processing unit
JPS54161854A (en) Input/output control system for information processor
JPS55157182A (en) Buffer memory
JPS55118170A (en) Memory access device
JPS5617441A (en) Program interruption system
JPS5419338A (en) Control system for data transfer
JPS5647845A (en) Address generator
JPS5335447A (en) Multi processor system
JPS53140948A (en) Interrupt processing system
JPS53116041A (en) System controller
JPS54838A (en) Data transfer system
JPS5425646A (en) Data processing unit
JPS5439541A (en) Data processor
JPS5396727A (en) State set system
JPS51127644A (en) Bill processing system
JPS57203155A (en) Data processor
JPS5394845A (en) Address control system for control memory
JPS53110440A (en) Prevention system for competition between processors
JPS5638630A (en) Data transfer apparatus