JPS57127220A - System for detecting turning-off of backup power source for memory - Google Patents

System for detecting turning-off of backup power source for memory

Info

Publication number
JPS57127220A
JPS57127220A JP56012044A JP1204481A JPS57127220A JP S57127220 A JPS57127220 A JP S57127220A JP 56012044 A JP56012044 A JP 56012044A JP 1204481 A JP1204481 A JP 1204481A JP S57127220 A JPS57127220 A JP S57127220A
Authority
JP
Japan
Prior art keywords
power source
ram3
contents
turned
bit pattern
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
JP56012044A
Other languages
Japanese (ja)
Inventor
Takeya Tanaka
Shigeru Hamada
Hitoshi Shibayama
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 JP56012044A priority Critical patent/JPS57127220A/en
Publication of JPS57127220A publication Critical patent/JPS57127220A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
    • G06F1/26—Power supply means, e.g. regulation thereof
    • G06F1/30—Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Stand-By Power Supply Arrangements (AREA)
  • Power Sources (AREA)
  • Techniques For Improving Reliability Of Storages (AREA)

Abstract

PURPOSE:To detect power-off of a power source for backup when a main power source is turned on again, by writing a specific bit pattern in a nonvolatile memory to store information before power-off of the main power source. CONSTITUTION:When a switch 6 is turned on, a CPU1 is started to compare a specific bit pattern stored in an ROM 2 with contents in a determined address of an RAM3. If they do not coincide with each other, all contents of the RAM3 are made ineffective, and the specific bit pattern stored in the ROM2 is written in a determined address of the RAM3. If they coincide with each other, all contents of the RAM3 are decided effective. If a power source 5 for backup is connected normally when the switch 6 is turned off, contents of the RAM3 are held because power is supplied continuously through a diode 8.
JP56012044A 1981-01-29 1981-01-29 System for detecting turning-off of backup power source for memory Pending JPS57127220A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56012044A JPS57127220A (en) 1981-01-29 1981-01-29 System for detecting turning-off of backup power source for memory

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56012044A JPS57127220A (en) 1981-01-29 1981-01-29 System for detecting turning-off of backup power source for memory

Publications (1)

Publication Number Publication Date
JPS57127220A true JPS57127220A (en) 1982-08-07

Family

ID=11794591

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56012044A Pending JPS57127220A (en) 1981-01-29 1981-01-29 System for detecting turning-off of backup power source for memory

Country Status (1)

Country Link
JP (1) JPS57127220A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2539527A1 (en) * 1983-01-19 1984-07-20 Diehl Gmbh & Co CONTROL CIRCUIT FOR A MICROCOMPUTER
EP0117735A1 (en) * 1983-02-28 1984-09-05 Deere & Company Computer control system
JPS6055456A (en) * 1983-09-05 1985-03-30 Mitsubishi Electric Corp Memory protecting circuit
EP0173967A2 (en) * 1984-08-31 1986-03-12 Hitachi, Ltd. Microprogram load unit
JPS6252650A (en) * 1985-08-30 1987-03-07 Chino Corp Memory checking method
JPH031209A (en) * 1989-05-29 1991-01-07 Rinnai Corp Control method using microcomputer
US5021776A (en) * 1988-07-11 1991-06-04 Yale Security Inc. Electronic combination of lock with changeable entry codes, lock-out and programming code
US5359569A (en) * 1991-10-29 1994-10-25 Hitachi Ltd. Semiconductor memory
EP1191426A2 (en) * 2000-08-21 2002-03-27 Sankyo Seiki Mfg. Co. Ltd. Power failure managing method and power failure managing device
US7080280B2 (en) 2001-06-28 2006-07-18 Nidec Sankyo Corporation Power failure sensing device and a card reader having a power failure sensing device

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2539527A1 (en) * 1983-01-19 1984-07-20 Diehl Gmbh & Co CONTROL CIRCUIT FOR A MICROCOMPUTER
EP0117735A1 (en) * 1983-02-28 1984-09-05 Deere & Company Computer control system
JPS6055456A (en) * 1983-09-05 1985-03-30 Mitsubishi Electric Corp Memory protecting circuit
EP0173967A2 (en) * 1984-08-31 1986-03-12 Hitachi, Ltd. Microprogram load unit
JPS6252650A (en) * 1985-08-30 1987-03-07 Chino Corp Memory checking method
US5021776A (en) * 1988-07-11 1991-06-04 Yale Security Inc. Electronic combination of lock with changeable entry codes, lock-out and programming code
JPH031209A (en) * 1989-05-29 1991-01-07 Rinnai Corp Control method using microcomputer
US5359569A (en) * 1991-10-29 1994-10-25 Hitachi Ltd. Semiconductor memory
EP1191426A2 (en) * 2000-08-21 2002-03-27 Sankyo Seiki Mfg. Co. Ltd. Power failure managing method and power failure managing device
EP1191426A3 (en) * 2000-08-21 2005-01-19 Sankyo Seiki Mfg. Co. Ltd. Power failure managing method and power failure managing device
US7080280B2 (en) 2001-06-28 2006-07-18 Nidec Sankyo Corporation Power failure sensing device and a card reader having a power failure sensing device

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