JPS56111198A - Correcting system for read only memory - Google Patents

Correcting system for read only memory

Info

Publication number
JPS56111198A
JPS56111198A JP1372780A JP1372780A JPS56111198A JP S56111198 A JPS56111198 A JP S56111198A JP 1372780 A JP1372780 A JP 1372780A JP 1372780 A JP1372780 A JP 1372780A JP S56111198 A JPS56111198 A JP S56111198A
Authority
JP
Japan
Prior art keywords
address
rom4
corrected
rom
ram
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
JP1372780A
Other languages
Japanese (ja)
Inventor
Kenichiro Oda
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP1372780A priority Critical patent/JPS56111198A/en
Publication of JPS56111198A publication Critical patent/JPS56111198A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/14—Error detection or correction of the data by redundancy in operation

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Techniques For Improving Reliability Of Storages (AREA)
  • Read Only Memory (AREA)
  • For Increasing The Reliability Of Semiconductor Memories (AREA)

Abstract

PURPOSE:To perform substantial rewrite of ROM simply and surely, by rewriting RAM and setting the identifying switching bit, in changing the content of ROM in response to the addresses between ROM and RAM. CONSTITUTION:When an address switching latch 8 is controlled and RAM is made to a write-in mode, the content of RAM6 is corrected with the access by the address of an address register 7 corresponding to the address accessing ROM4 from a CPU5, the output 15 is 1, and the switching bit 16 is set to 1. After this correction, when readout is made via the CPU5, since the bit 16 is 0 at nonset state to the address not corrected with ROM4, the readout data of ROM4 is fed to an interface common control circuit 3 via the logical sum gate 21, and at accessing to the bits corrected, the data of ROM4 is inverted and corrected with the exclusive logical sum gate 10 to be fed to the circuit 3, allowing to rewirte the content of ROM simply and surely.
JP1372780A 1980-02-08 1980-02-08 Correcting system for read only memory Pending JPS56111198A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1372780A JPS56111198A (en) 1980-02-08 1980-02-08 Correcting system for read only memory

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1372780A JPS56111198A (en) 1980-02-08 1980-02-08 Correcting system for read only memory

Publications (1)

Publication Number Publication Date
JPS56111198A true JPS56111198A (en) 1981-09-02

Family

ID=11841269

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1372780A Pending JPS56111198A (en) 1980-02-08 1980-02-08 Correcting system for read only memory

Country Status (1)

Country Link
JP (1) JPS56111198A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61230699A (en) * 1985-04-05 1986-10-14 Nippon Denki Kanji Syst Kk Storage system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61230699A (en) * 1985-04-05 1986-10-14 Nippon Denki Kanji Syst Kk Storage system

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