JPS6462023A - Clock system for semiconductor integrated circuit - Google Patents

Clock system for semiconductor integrated circuit

Info

Publication number
JPS6462023A
JPS6462023A JP62217804A JP21780487A JPS6462023A JP S6462023 A JPS6462023 A JP S6462023A JP 62217804 A JP62217804 A JP 62217804A JP 21780487 A JP21780487 A JP 21780487A JP S6462023 A JPS6462023 A JP S6462023A
Authority
JP
Japan
Prior art keywords
band
frequency
semiconductor integrated
integrated circuit
clock
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
JP62217804A
Other languages
Japanese (ja)
Other versions
JP2713916B2 (en
Inventor
Terumi Sawase
Hideo Nakamura
Kenji Kaneko
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 JP62217804A priority Critical patent/JP2713916B2/en
Publication of JPS6462023A publication Critical patent/JPS6462023A/en
Application granted granted Critical
Publication of JP2713916B2 publication Critical patent/JP2713916B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Landscapes

  • Semiconductor Memories (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
  • Dram (AREA)

Abstract

PURPOSE:To prevent malfunction due to noise introduced to a clock terminal and an incorrect high frequency clock by providing a means limiting the oscillating frequency band of an oscillation means. CONSTITUTION:A phase comparator 10 compares the phase of an output of a frequency divider circuit 13 with that of an external clock supplied from the outside of a semiconductor integrated circuit 1 via a clock line 6, supplies phase difference information to a voltage converter 11, which converts the phase difference information into a control voltage of a voltage controlled oscillator (VCO) 12. An oscillation band control circuit 16 acts like limiting a control voltage applied to a VCO 12 based on a signal of a band control line 15a. That is, the upper or lower limit of the oscillated frequency of the VCO 12 is controlled. Thus, even when a low frequency clock below the band frequency or a high frequency over the band frequency is inputted in the actual operation, the signal is band-limited in the semiconductor integrated circuit. Thus, malfunction of the semiconductor integrated circuit 1 is prevented.
JP62217804A 1987-09-02 1987-09-02 Semiconductor integrated circuit Expired - Fee Related JP2713916B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62217804A JP2713916B2 (en) 1987-09-02 1987-09-02 Semiconductor integrated circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62217804A JP2713916B2 (en) 1987-09-02 1987-09-02 Semiconductor integrated circuit

Publications (2)

Publication Number Publication Date
JPS6462023A true JPS6462023A (en) 1989-03-08
JP2713916B2 JP2713916B2 (en) 1998-02-16

Family

ID=16709996

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62217804A Expired - Fee Related JP2713916B2 (en) 1987-09-02 1987-09-02 Semiconductor integrated circuit

Country Status (1)

Country Link
JP (1) JP2713916B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02107018A (en) * 1988-10-17 1990-04-19 Hitachi Ltd Voltage controlled oscillator
US6799242B1 (en) 1999-03-05 2004-09-28 Sanyo Electric Co., Ltd. Optical disc player with sleep mode

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50105364A (en) * 1974-01-28 1975-08-20
JPS5974735A (en) * 1982-10-20 1984-04-27 Sanyo Electric Co Ltd Voltage control oscillator device
JPS63286091A (en) * 1987-05-19 1988-11-22 Pioneer Electronic Corp Method for controlling pll circuit

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50105364A (en) * 1974-01-28 1975-08-20
JPS5974735A (en) * 1982-10-20 1984-04-27 Sanyo Electric Co Ltd Voltage control oscillator device
JPS63286091A (en) * 1987-05-19 1988-11-22 Pioneer Electronic Corp Method for controlling pll circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02107018A (en) * 1988-10-17 1990-04-19 Hitachi Ltd Voltage controlled oscillator
US6799242B1 (en) 1999-03-05 2004-09-28 Sanyo Electric Co., Ltd. Optical disc player with sleep mode
US7047353B2 (en) 1999-03-05 2006-05-16 Sanyo Electric Co., Ltd. Optical disc player with sleep mode

Also Published As

Publication number Publication date
JP2713916B2 (en) 1998-02-16

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Legal Events

Date Code Title Description
LAPS Cancellation because of no payment of annual fees