JPS5797136A - Peripheral controller - Google Patents

Peripheral controller

Info

Publication number
JPS5797136A
JPS5797136A JP17283280A JP17283280A JPS5797136A JP S5797136 A JPS5797136 A JP S5797136A JP 17283280 A JP17283280 A JP 17283280A JP 17283280 A JP17283280 A JP 17283280A JP S5797136 A JPS5797136 A JP S5797136A
Authority
JP
Japan
Prior art keywords
port
register
priority
given
start request
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
JP17283280A
Other languages
Japanese (ja)
Inventor
Kiyoshi Sakai
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.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co 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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP17283280A priority Critical patent/JPS5797136A/en
Publication of JPS5797136A publication Critical patent/JPS5797136A/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
    • G06F13/22—Handling requests for interconnection or transfer for access to input/output bus using successive scanning, e.g. polling
    • G06F13/225—Handling requests for interconnection or transfer for access to input/output bus using successive scanning, e.g. polling with priority control

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 increase the efficiency of a specified process, by securing an optional selection for the I/O port number to which a reply should be preferentially given and increasing the priority of the I/O port. CONSTITUTION:I/O ports 0-3 are successively switched by varying the contents of a register 5 to check the presence or absence of a start request. If a start request is given, a priority port existence signal 9 is examined. When the signal 9 is set at ''1'', the present port number stored in the register 5 is shunted to a register 6. Then the port number to which a reply should be preferentially given and which is selected by a rotary switch 7 is set to the register 5 through a coding circuit 8. In this case, if a start request is given from a priority port, the process is executed in the state under which the priority port is selected. Thus the channel connected to this priority port can be processed in preference to the channels which are connected to other ports.
JP17283280A 1980-12-08 1980-12-08 Peripheral controller Pending JPS5797136A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP17283280A JPS5797136A (en) 1980-12-08 1980-12-08 Peripheral controller

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP17283280A JPS5797136A (en) 1980-12-08 1980-12-08 Peripheral controller

Publications (1)

Publication Number Publication Date
JPS5797136A true JPS5797136A (en) 1982-06-16

Family

ID=15949171

Family Applications (1)

Application Number Title Priority Date Filing Date
JP17283280A Pending JPS5797136A (en) 1980-12-08 1980-12-08 Peripheral controller

Country Status (1)

Country Link
JP (1) JPS5797136A (en)

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