JPS5549723A - Clock switching unit - Google Patents

Clock switching unit

Info

Publication number
JPS5549723A
JPS5549723A JP12154078A JP12154078A JPS5549723A JP S5549723 A JPS5549723 A JP S5549723A JP 12154078 A JP12154078 A JP 12154078A JP 12154078 A JP12154078 A JP 12154078A JP S5549723 A JPS5549723 A JP S5549723A
Authority
JP
Japan
Prior art keywords
clock
gate
output
request
switch
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
JP12154078A
Other languages
Japanese (ja)
Inventor
Junichi Ikuma
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 JP12154078A priority Critical patent/JPS5549723A/en
Publication of JPS5549723A publication Critical patent/JPS5549723A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To switch clocks without stopping a data processing unit by switching them at a time when the phase relation between the current clock and another clock becomes optimum.
CONSTITUTION: In case of the frequency of clock A higher than that of clock B, when a request to switch clock B to clock A or switch clock B to clock A is issued, the request is transferred to the data input of FF26 through OR gate 25, and AND between the output of FF26 and the inversion signal of OR gate 24 is operated by AND gate 28 when the output of OR gate 24 is "0", and timer 29 is triggered by this signal. The output of timer 29 becomes "1" and is broken to "0" after a fixed time. At this break time, the output of inverter 30 triggers FF31. In case that FF31 is set to "0", clock B is taken in by AND gate 34 and is outputted as clock C through OR gate 35. The power settlement signal of the processing unit can be used as the clock switching request.
COPYRIGHT: (C)1980,JPO&Japio
JP12154078A 1978-10-04 1978-10-04 Clock switching unit Pending JPS5549723A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12154078A JPS5549723A (en) 1978-10-04 1978-10-04 Clock switching unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12154078A JPS5549723A (en) 1978-10-04 1978-10-04 Clock switching unit

Publications (1)

Publication Number Publication Date
JPS5549723A true JPS5549723A (en) 1980-04-10

Family

ID=14813765

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12154078A Pending JPS5549723A (en) 1978-10-04 1978-10-04 Clock switching unit

Country Status (1)

Country Link
JP (1) JPS5549723A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59164022U (en) * 1983-04-18 1984-11-02 旭光学工業株式会社 fiberscope imaging device
JPS59164023U (en) * 1983-04-18 1984-11-02 旭光学工業株式会社 fiberscope imaging device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51144539A (en) * 1975-06-09 1976-12-11 Toshiba Corp Synchronized method of plural digital circuits
JPS5294048A (en) * 1976-02-04 1977-08-08 Hitachi Ltd Clock switch control system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51144539A (en) * 1975-06-09 1976-12-11 Toshiba Corp Synchronized method of plural digital circuits
JPS5294048A (en) * 1976-02-04 1977-08-08 Hitachi Ltd Clock switch control system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59164022U (en) * 1983-04-18 1984-11-02 旭光学工業株式会社 fiberscope imaging device
JPS59164023U (en) * 1983-04-18 1984-11-02 旭光学工業株式会社 fiberscope imaging device

Similar Documents

Publication Publication Date Title
JPS5336439A (en) Information processor
JPS53139456A (en) Clock driver circuit
JPS5245978A (en) Electronic wrist watch
JPS5543422A (en) Electronic timer
JPS5441660A (en) Timer
JPS5368944A (en) Clock conroller
JPS5415632A (en) Switch device for computer
JPS53129556A (en) Clock control system
JPS55144586A (en) Electronic clock having snoozing monitor function
JPS5232222A (en) Sampling pulse producting circuit
JPS53138640A (en) Power source throw-in system
JPS5359940A (en) High frequency heating system
JPS5354332A (en) High frequency heater
JPS5228254A (en) Contactless relay
JPS5282491A (en) Crystal watch
JPS5243945A (en) Control device of inverter
JPS5530715A (en) Digital timer circuit
JPS538170A (en) Alarm electronic watch
JPS5671478A (en) Gate interrupting system for thyristor type inverter
JPS538843A (en) High frequency heater
JPS5495134A (en) Data processing unit
JPS54139446A (en) Process mode control unit
JPS56106404A (en) Oscillating circuit
JPS5332776A (en) Phase comparison circuit
JPS5345569A (en) Electronic watch