IP Library Granted Patent US 7,522,364
Granted Patent B2
US 7,522,364 · App. 11/345,470 · Granted Apr 21, 2009

Control circuit for information storage device

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Quick Facts
Patent No.
US 7,522,364
App. No.
11/345,470
Granted
Apr 21, 2009
Kind
B2
Abstract

To reduce power consumption of an information storage device, a control circuit for the information storage device stops the supply of a formatter clock or an ECC unit clock simultaneously with a seek operation. When a clock stop time has elapsed by the time obtained by subtracting at least a time required for restarting the formatter or the ECC unit from a seek time, the control circuit restarts the supply of the formatter clock or the ECC unit clock.

Claims (15)

1. A control circuit for an information storage device, comprising:

seek operation means for performing tracking control to move a head to a target track based on the servo information prerecorded in a medium;

clock gate means for stopping a supply of a clock signals to a formatter unit and an ECC (error correcting and checking) unit during a seek operation and restarting the supply of the clock signals to the formatter unit and the ECC unit before the seek operation is finished; and

time setting means for setting time obtained by subtracting at least a time required for restarting the formatter unit and the ECC unit from a seek time in a timer;

wherein the clock gate means restarts the supply of the clock signals to the formatter unit and the ECC unit when the time set in the timer has elapsed.

2. A control circuit for an information storage device, comprising:

seek operation means for performing tracking control to move a head to a target track based on the servo information prerecorded in a medium;

clock gate means for stopping a supply of a clock signals to a formatter unit and an ECC (error correcting and checking) unit during a seek operation and restarting the supply of the clock signals to the formatter unit and the ECC unit before the seek operation is finished; and

monitoring means for monitoring by firmware a clock stop time during which the clock signals are stopped;

wherein the clock gate means restarts the supply of the clock signals to the formatter unit and the ECC unit when the clock stop time has elapsed by a time obtained by subtracting at least a time required for restarting the formatter unit and the ECC unit from a seek time.

3. A magnetic disk unit, comprising:

seek operation means for performing tracking control to move a head to a target track based on the servo information prerecorded in a medium;

clock gate means for stopping a supply of a clock signals to a formatter unit and an ECC (error correcting and checking) unit during a seek operation and restarting the supply of the clock signals to the formatter unit and the ECC unit before the seek operation is finished; and

time setting means for setting time obtained by subtracting at least a time required for restarting the formatter unit and the ECC unit from a seek time in a timer;

wherein the clock gate means restarts the supply of the clock signals to the formatter unit and the ECC unit when the time set in the timer has elapsed.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 8, 2012
From: TOSHIBA STORAGE DEVICE CORPORATION
To: KABUSHIKI KAISHA TOSHIBA
Reel/Frame 027674/0653 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 23, 2009
From: FUJITSU LIMITED
To: TOSHIBA STORAGE DEVICE CORPORATION
Reel/Frame 023558/0225 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 1, 2006
From: KUBOHARA, RYUKI; TOMITA, ISAMU
To: FUJITSU LIMITED
Reel/Frame 017548/0046 →