JPS57150017A - Direct memory access system - Google Patents

Direct memory access system

Info

Publication number
JPS57150017A
JPS57150017A JP3504781A JP3504781A JPS57150017A JP S57150017 A JPS57150017 A JP S57150017A JP 3504781 A JP3504781 A JP 3504781A JP 3504781 A JP3504781 A JP 3504781A JP S57150017 A JPS57150017 A JP S57150017A
Authority
JP
Japan
Prior art keywords
generator
signal
memory access
direct memory
data
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
JP3504781A
Other languages
Japanese (ja)
Inventor
Kenkichi Kubo
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 JP3504781A priority Critical patent/JPS57150017A/en
Publication of JPS57150017A publication Critical patent/JPS57150017A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
    • G06F13/14—Handling requests for interconnection or transfer
    • G06F13/20—Handling requests for interconnection or transfer for access to input/output bus
    • G06F13/28—Handling requests for interconnection or transfer for access to input/output bus using burst mode transfer, e.g. direct memory access DMA, cycle steal

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Bus Control (AREA)

Abstract

PURPOSE:To use a direct memory access controlling circuit incommon by plural devices, by adding a means which discriminates that a transfer request exists at another device. CONSTITUTION:When a direct memory access DMA request signal A is transmitted (to a character generator 7), a control part 8 receives the signal A and a DMA controlling part 9 discriminates the contents of the signal A. When the signal A is decided to be related with the generated 7, the part 9 forms a circuit that enables the transfer of data between the part 8 and the generator 7. As a result, the data is transferred between a memory 2 and the generator 7 via a common bus and the part 8. Thus the DMA controling part required for the transfer of data to the memory 2 is eliminated for the generator 7.
JP3504781A 1981-03-11 1981-03-11 Direct memory access system Pending JPS57150017A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3504781A JPS57150017A (en) 1981-03-11 1981-03-11 Direct memory access system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3504781A JPS57150017A (en) 1981-03-11 1981-03-11 Direct memory access system

Publications (1)

Publication Number Publication Date
JPS57150017A true JPS57150017A (en) 1982-09-16

Family

ID=12431118

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3504781A Pending JPS57150017A (en) 1981-03-11 1981-03-11 Direct memory access system

Country Status (1)

Country Link
JP (1) JPS57150017A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6336353A (en) * 1986-07-30 1988-02-17 Anritsu Corp Vme data transmission equipment
US4786102A (en) * 1986-04-15 1988-11-22 Webasto Ag Fahrzeugtechnik Sunroof apparatus of vehicle roof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4786102A (en) * 1986-04-15 1988-11-22 Webasto Ag Fahrzeugtechnik Sunroof apparatus of vehicle roof
JPS6336353A (en) * 1986-07-30 1988-02-17 Anritsu Corp Vme data transmission equipment

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