JPH01220300A - Nonvolatile semiconductor memory - Google Patents

Nonvolatile semiconductor memory

Info

Publication number
JPH01220300A
JPH01220300A JP4601388A JP4601388A JPH01220300A JP H01220300 A JPH01220300 A JP H01220300A JP 4601388 A JP4601388 A JP 4601388A JP 4601388 A JP4601388 A JP 4601388A JP H01220300 A JPH01220300 A JP H01220300A
Authority
JP
Japan
Prior art keywords
write
nonvolatile memory
counter
times
outside
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
JP4601388A
Inventor
Tetsuro Hirayama
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 JP4601388A priority Critical patent/JPH01220300A/en
Publication of JPH01220300A publication Critical patent/JPH01220300A/en
Application status is Pending legal-status Critical

Links

Abstract

PURPOSE: To recognize the limitation of the number of times of write from the outside and to guarantee a write operation by containing a counter for counting the number of times of write, a nonvolatile storage part for storing a count value, and a means for monitoring the excess of the count value over a prescribed count value from the outside.
CONSTITUTION: The counter 2 is counted up by one at every erasure and write of a nonvolatile memory 1. Afterwards, in case of detecting the OFF of a power source, the content of the counter 2 is written on a nonvolatile memory 3, and adversely, when the ON of the power source is detected, the content of the nonvolatile memory 3 is loaded on the counter 2. Thenceforth, the counter 2 is counted up by one at every erasure and write of the nonvolatile memory 1, and thus, the accumulated number of times of write on the nonvolatile memory 1 is stored in the nonvolatile memory 3. And since the output of a comparator 5 changes when the value exceeds a critical value, it is possible to recognize the limitation from the outside easily by monitoring the change from an output terminal 23. In such a way, the write can be guaranteed as the one effective electrically.
COPYRIGHT: (C)1989,JPO&Japio
JP4601388A 1988-02-29 1988-02-29 Nonvolatile semiconductor memory Pending JPH01220300A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4601388A JPH01220300A (en) 1988-02-29 1988-02-29 Nonvolatile semiconductor memory

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4601388A JPH01220300A (en) 1988-02-29 1988-02-29 Nonvolatile semiconductor memory

Publications (1)

Publication Number Publication Date
JPH01220300A true JPH01220300A (en) 1989-09-01

Family

ID=12735174

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4601388A Pending JPH01220300A (en) 1988-02-29 1988-02-29 Nonvolatile semiconductor memory

Country Status (1)

Country Link
JP (1) JPH01220300A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04115398U (en) * 1991-03-27 1992-10-13
JPH0527924A (en) * 1991-07-12 1993-02-05 Internatl Business Mach Corp <Ibm> External memory system using semiconductor memory and its control method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04115398U (en) * 1991-03-27 1992-10-13
JPH0527924A (en) * 1991-07-12 1993-02-05 Internatl Business Mach Corp <Ibm> External memory system using semiconductor memory and its control method

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