JPS6436345A - Memory protecting system - Google Patents

Memory protecting system

Info

Publication number
JPS6436345A
JPS6436345A JP62191709A JP19170987A JPS6436345A JP S6436345 A JPS6436345 A JP S6436345A JP 62191709 A JP62191709 A JP 62191709A JP 19170987 A JP19170987 A JP 19170987A JP S6436345 A JPS6436345 A JP S6436345A
Authority
JP
Japan
Prior art keywords
processing unit
central processing
protect
state
status signal
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
JP62191709A
Other languages
Japanese (ja)
Inventor
Tatsuya Iwano
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.)
NEC Corp
Original Assignee
NEC 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 NEC Corp filed Critical NEC Corp
Priority to JP62191709A priority Critical patent/JPS6436345A/en
Publication of JPS6436345A publication Critical patent/JPS6436345A/en
Pending legal-status Critical Current

Links

Landscapes

  • Storage Device Security (AREA)
  • Debugging And Monitoring (AREA)

Abstract

PURPOSE:To surely perform memory protect check, by providing a protect pattern corresponding to the status signal of a central processing unit in a memory device, and performing protect check fitted for the operation of the central processing unit. CONSTITUTION:The titled system is constituted of the central processing unit 10 which outputs the status signal to show the operating states of the readout of a program, that of data, or the write of the data and also performs every kind of operation, the memory device 20 to store a protect pattern corresponding to every state, a selection circuit 50 which makes access to the address of the memory device 20 corresponding to the state of the central processing unit 10 and selects the protect pattern at every state, and a detection circuit 80 which controls the operation of the central processing unit 10 by monitoring the validity of the operation of the central processing unit 10 based on the status signal and the address made access at the selection circuit 50. In such a way, it is possible to perform memory protection appropriately corresponding to the operating state of the central processing unit 10.
JP62191709A 1987-07-31 1987-07-31 Memory protecting system Pending JPS6436345A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62191709A JPS6436345A (en) 1987-07-31 1987-07-31 Memory protecting system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62191709A JPS6436345A (en) 1987-07-31 1987-07-31 Memory protecting system

Publications (1)

Publication Number Publication Date
JPS6436345A true JPS6436345A (en) 1989-02-07

Family

ID=16279173

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62191709A Pending JPS6436345A (en) 1987-07-31 1987-07-31 Memory protecting system

Country Status (1)

Country Link
JP (1) JPS6436345A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04117541A (en) * 1990-09-07 1992-04-17 Nec Corp Memory controller

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04117541A (en) * 1990-09-07 1992-04-17 Nec Corp Memory controller

Similar Documents

Publication Publication Date Title
US4783801A (en) Apparatus for protecting secret information
US4332009A (en) Memory protection system
CA2031506A1 (en) Protection system for a memory cartridge
KR880003244A (en) Microprocessor executing data transfer retry
NO895115L (en) PROTECTIVE DEVICE FOR AN ELECTRONIC CIRCUIT, AS USING THE DEVICE FOR AA PROTECT A READING TERMINAL FOR MAGNET CARDS AND / OR MICROPROCESSOR CARDS.
EP0991012A4 (en) Ic card
JPS5539994A (en) Multiprocessor system
GB2203318B (en) Data processing apparatus with memory control function based on cpu state detection
JPS6436345A (en) Memory protecting system
JPS6450148A (en) Memory resetting circuit
JPS577690A (en) Initial program loading system
JPS57164347A (en) Undefined instruction detector for one chip microcomputer
JPS5663652A (en) Information processing unit
JPS6476343A (en) Cache memory control system
JPS5593596A (en) Memory unit
JPS5634194A (en) Memory unit
JPS5785145A (en) Address detection system
EP0297890A3 (en) Apparatus and method for data induced condition signaling
SU1103291A1 (en) Adaptive device for protecting memory
JPS57137972A (en) Character out position detecting method
JPS5353932A (en) Fault detection system for memory address line
KR890010715A (en) Memory destruction prevention circuit and method
JPS578999A (en) Memory controller
JPS57146349A (en) Discriminating method of performance of check circuit
JPS575166A (en) Memory protection system