JPS57105016A - Clock source switching system - Google Patents

Clock source switching system

Info

Publication number
JPS57105016A
JPS57105016A JP18149980A JP18149980A JPS57105016A JP S57105016 A JPS57105016 A JP S57105016A JP 18149980 A JP18149980 A JP 18149980A JP 18149980 A JP18149980 A JP 18149980A JP S57105016 A JPS57105016 A JP S57105016A
Authority
JP
Japan
Prior art keywords
clock
gate
stage
delaying circuit
source
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.)
Granted
Application number
JP18149980A
Other languages
Japanese (ja)
Other versions
JPS6250034B2 (en
Inventor
Ikutoshi Igawa
Masato Suyama
Takao Suzuki
Akira Ikuta
Masateru Tagami
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
Hitachi Ltd
NEC Corp
Nippon Telegraph and Telephone Corp
Oki Electric Industry Co Ltd
Original Assignee
Fujitsu Ltd
Hitachi Ltd
NEC Corp
Nippon Telegraph and Telephone Corp
Oki Electric Industry Co Ltd
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 Fujitsu Ltd, Hitachi Ltd, NEC Corp, Nippon Telegraph and Telephone Corp, Oki Electric Industry Co Ltd, Nippon Electric Co Ltd filed Critical Fujitsu Ltd
Priority to JP18149980A priority Critical patent/JPS57105016A/en
Publication of JPS57105016A publication Critical patent/JPS57105016A/en
Publication of JPS6250034B2 publication Critical patent/JPS6250034B2/ja
Granted 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
    • G06F1/04—Generating or distributing clock signals or signals derived directly therefrom

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
  • Exchange Systems With Centralized Control (AREA)

Abstract

PURPOSE:To guarantee the continuity of a clock when switching a clock source, by detecting a clock (0) level, taking the timing in a delaying circuit, normalizing it, and synchronizing the clock. CONSTITUTION:When a switching signal applied to a clock source selecting signal supply port 105' of ''1'' system is switched at a point 204, signals of supply ports 105, 105' points become waveforms 202, 202', and the first stage of a delaying circuit 109' of ''1'' system is set to ''1''. When the first stage of a delaying circuit 109 of ''0'' system is set to ''0'', gate signals 107, 108 become ''0'' level, a gate of a clock oscillation source 101 is closed, a clock to ''0'' system and ''1'' system is stopped, and a gate signal 106 is made to pass through. Subsequently, when the second stage of the circuit 109' is set to ''1'', the second stage of the delaying circuit 109 of ''0'' system is set to ''0''. Subsequently, when the third stages of the circuits 109, 109' are set to ''0'' and ''1'', respectively, a gate to which gate signals 107', 108' are supplied is opened, and a clock waveform synchronizing with waveforms 203, 203' is fetched once again to supply ports 104, 104' from a new clock oscillation source 101'.
JP18149980A 1980-12-22 1980-12-22 Clock source switching system Granted JPS57105016A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP18149980A JPS57105016A (en) 1980-12-22 1980-12-22 Clock source switching system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP18149980A JPS57105016A (en) 1980-12-22 1980-12-22 Clock source switching system

Publications (2)

Publication Number Publication Date
JPS57105016A true JPS57105016A (en) 1982-06-30
JPS6250034B2 JPS6250034B2 (en) 1987-10-22

Family

ID=16101822

Family Applications (1)

Application Number Title Priority Date Filing Date
JP18149980A Granted JPS57105016A (en) 1980-12-22 1980-12-22 Clock source switching system

Country Status (1)

Country Link
JP (1) JPS57105016A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5822429A (en) * 1981-08-04 1983-02-09 Nec Corp Clock switching circuit
JPS59133622A (en) * 1983-01-21 1984-08-01 Oki Electric Ind Co Ltd Clock switching control system
JPS6010830A (en) * 1983-06-29 1985-01-21 Fujitsu Ltd System switching system
JPS6095623A (en) * 1983-10-31 1985-05-29 Hitachi Ltd Information processing system
JPS60502274A (en) * 1983-11-07 1985-12-26 モトロ−ラ・インコ−ポレ−テツド Synthetic clock microcomputer saves power
JPS62192815A (en) * 1986-02-20 1987-08-24 Fujitsu Ltd Clock switching circuit
JPH086854A (en) * 1993-12-23 1996-01-12 Unisys Corp Outboard-file-cache external processing complex

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3936212A1 (en) * 1989-10-31 1991-05-02 Gebr Hennig Gmbh METHOD FOR PRODUCING A TELESCOPE COVER

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5368944A (en) * 1976-12-01 1978-06-19 Toshiba Corp Clock conroller
JPS55944A (en) * 1978-06-19 1980-01-07 Fujitsu Ltd Clock switching system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5368944A (en) * 1976-12-01 1978-06-19 Toshiba Corp Clock conroller
JPS55944A (en) * 1978-06-19 1980-01-07 Fujitsu Ltd Clock switching system

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5822429A (en) * 1981-08-04 1983-02-09 Nec Corp Clock switching circuit
JPH0133844B2 (en) * 1981-08-04 1989-07-17 Nippon Electric Co
JPS59133622A (en) * 1983-01-21 1984-08-01 Oki Electric Ind Co Ltd Clock switching control system
JPS6010830A (en) * 1983-06-29 1985-01-21 Fujitsu Ltd System switching system
JPH034145B2 (en) * 1983-06-29 1991-01-22 Fujitsu Ltd
JPS6095623A (en) * 1983-10-31 1985-05-29 Hitachi Ltd Information processing system
JPS60502274A (en) * 1983-11-07 1985-12-26 モトロ−ラ・インコ−ポレ−テツド Synthetic clock microcomputer saves power
JPH0412842B2 (en) * 1983-11-07 1992-03-05 Motorola Inc
JPS62192815A (en) * 1986-02-20 1987-08-24 Fujitsu Ltd Clock switching circuit
JPH0523441B2 (en) * 1986-02-20 1993-04-02 Fujitsu Ltd
JPH086854A (en) * 1993-12-23 1996-01-12 Unisys Corp Outboard-file-cache external processing complex

Also Published As

Publication number Publication date
JPS6250034B2 (en) 1987-10-22

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