JPS5685130A - Rom access circuit - Google Patents

Rom access circuit

Info

Publication number
JPS5685130A
JPS5685130A JP16302579A JP16302579A JPS5685130A JP S5685130 A JPS5685130 A JP S5685130A JP 16302579 A JP16302579 A JP 16302579A JP 16302579 A JP16302579 A JP 16302579A JP S5685130 A JPS5685130 A JP S5685130A
Authority
JP
Japan
Prior art keywords
data
memory
counter
rom
latched
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
JP16302579A
Other languages
Japanese (ja)
Inventor
Tatsuhiro Imada
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric 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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP16302579A priority Critical patent/JPS5685130A/en
Publication of JPS5685130A publication Critical patent/JPS5685130A/en
Pending legal-status Critical Current

Links

Landscapes

  • Bus Control (AREA)
  • Read Only Memory (AREA)

Abstract

PURPOSE: To eliminate the waiting time of microprocessor even with use of the ROM having a long access time, by giving an access to other memory data after dividing the memory data read out of the ROM into 5n units for processing.
CONSTITUTION: The address delivered from the microprocessor 4 is preset to the preset counter 2, and the contents of the counter are given to the memory device 1 to send the memory data by one word (32 bits) for latching at the latch memory 14. The 8-bit data of the first division part among the latched data is selected by the multiplexer 16 to be sent to the data bus 6. After this, the count-up signal CU is applied to the counter 2 with the second address given to the device 1 to read out the memory data. Then the data of the second, third and fourth division parts of the memory 14 are sent to the bus 6. After this, the second data is latched.
COPYRIGHT: (C)1981,JPO&Japio
JP16302579A 1979-12-12 1979-12-12 Rom access circuit Pending JPS5685130A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16302579A JPS5685130A (en) 1979-12-12 1979-12-12 Rom access circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16302579A JPS5685130A (en) 1979-12-12 1979-12-12 Rom access circuit

Publications (1)

Publication Number Publication Date
JPS5685130A true JPS5685130A (en) 1981-07-11

Family

ID=15765749

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16302579A Pending JPS5685130A (en) 1979-12-12 1979-12-12 Rom access circuit

Country Status (1)

Country Link
JP (1) JPS5685130A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58102392A (en) * 1981-12-14 1983-06-17 Matsushita Electric Ind Co Ltd Read-only memory control circuit
JPS59226923A (en) * 1983-05-27 1984-12-20 インタ−ナシヨナル　ビジネス　マシ−ンズ　コ−ポレ−シヨン Bus interface apparatus
JPS61286942A (en) * 1985-06-13 1986-12-17 Victor Co Of Japan Ltd Memory element access controller
JPS63118966A (en) * 1986-11-07 1988-05-23 Nec Corp Data transfer controller
JPS6460894A (en) * 1987-08-31 1989-03-07 Fujitsu Ltd Non-volatile semiconductor memory device
JPH0512894A (en) * 1991-07-05 1993-01-22 Mitsubishi Electric Corp Microcomputer and its rom reading method

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58102392A (en) * 1981-12-14 1983-06-17 Matsushita Electric Ind Co Ltd Read-only memory control circuit
JPS59226923A (en) * 1983-05-27 1984-12-20 インタ−ナシヨナル　ビジネス　マシ−ンズ　コ−ポレ−シヨン Bus interface apparatus
JPS61286942A (en) * 1985-06-13 1986-12-17 Victor Co Of Japan Ltd Memory element access controller
JPS63118966A (en) * 1986-11-07 1988-05-23 Nec Corp Data transfer controller
JPS6460894A (en) * 1987-08-31 1989-03-07 Fujitsu Ltd Non-volatile semiconductor memory device
JPH0512894A (en) * 1991-07-05 1993-01-22 Mitsubishi Electric Corp Microcomputer and its rom reading method

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