JPH06309776A - Magnetic disk device and data read-out and write-in method - Google Patents

Abstract

PURPOSE:To reduce power consumption by reducing the number of the rotary starting and rotating time of a spindle motor. CONSTITUTION:When power is turned on at a first time, a CPU 1 moves an actuator 11 on a cylinder in which a target sector is arranged by controlling a VCM 12 with a servo circuit 7 after the CPU rotates a spindle motor 15 with a motor controlling circuit 8. Then, the CPU out start data from the sector with a hread 10 via a read/write circuit 6 and transfers the data to a host computer 30 via an interface 9 and simultaneously writes the data in the read area of a non-volatile memory 5 to store. When power are turned on at and after next time, the CPU reads the start data out of the area of the non-volatile memory 5 and transfers the data to the host computer 30 via the interface 9. Thus, the number of the rotary starting and rotation time of the motor are reduced since the spindle motor is not needed to rotate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a method for reducing power consumption of a spindle motor.

[0002]

2. Description of the Related Art Conventionally, a magnetic disk device built in an information processing apparatus using a battery as a drive source, such as a notebook personal computer, has a spindle motor of the magnetic disk device at the same time when the power of the main body is turned on. It is common to rotate and read the information necessary for starting the device from the magnetic disk. Further, this type of magnetic disk device has a power saving function for automatically stopping the spindle motor when there is no access from the host computer for a certain period of time. When the host computer of the apparatus again writes / reads data to / from the magnetic disk apparatus in which the spindle motor has once stopped, the spindle motor is rotated again,
Data reading / writing is performed on the magnetic disk.

By the way, the performance of the magnetic disk device is determined by the seek time for moving the head to the cylinder having the target sector, the waiting time until the rotation of the spindle motor reaches a steady value, and the target sector on the cylinder being the head. It depends on the rotation waiting time, the linear recording density, the size of the cache memory and the operation method. In particular, the shortening of the access time to the magnetic disk device can be achieved by shortening the seek time, the high speed rotation of the spindle motor, the improvement of the utilization of the cache memory, etc., and various measures have been taken.

For a battery-powered information processing device such as a notebook personal computer, it is possible to ignore the power consumed by the spindle motor of the mounted magnetic disk device and the power consumed by peripheral circuits such as the read / write circuit and the servo circuit. Can not. Therefore, as described above, while the magnetic disk device is not accessed, the spindle motor is stopped to control the power consumption. In the case where the access time to the magnetic disk is shortened by performing the high-speed rotation of the spindle motor of the magnetic disk device to reduce the above-mentioned rotation waiting time despite the above control. , The power consumption of the spindle motor increases. Therefore, if unnecessary rotation of the spindle motor is avoided as much as possible and power consumption is not saved, the access time to the magnetic disk device is shortened, but the battery for operating the device immediately rises, and There is a drawback that the operating time of the processing device becomes short.

[0005]

In a battery-driven information device such as a notebook personal computer, a spindle motor of a magnetic disk device is rotated only when necessary to save power consumption. But,
Recently, in order to improve the performance of the magnetic disk device, the spindle motor is rotated at a higher speed and the power consumption thereof tends to increase. Therefore, further reduction of the power consumption of the spindle motor is further improved, and If the increase in the power consumption of the magnetic disk device is not reduced, the battery will be quickly exhausted and the operation time of the information processing device will be shortened even if the performance of the magnetic disk device is improved.

Therefore, the present invention provides a magnetic disk device and a data read / write method capable of reducing power consumption by eliminating the above-mentioned drawbacks and further reducing the number of times of rotation start of the spindle motor and the time during which the spindle motor is rotating. The purpose is to do.

[0007]

According to the present invention, in a magnetic disk device for reading and writing data on a magnetic disk rotated by a spindle motor, a rewritable non-volatile memory for storing data and a predetermined memory read from the magnetic disk. Writing means for writing the data in the non-volatile memory, a judging means for judging whether or not read request data from the device on the access side exists in the non-volatile memory, and the request data by the judging means. When it is determined that the spindle motor is present in the nonvolatile memory and the spindle motor is in a stopped state at this time, the spindle motor is provided with a reading means for reading data from the nonvolatile memory and sending the data to the access device side. Have a configuration.

[0008]

In the magnetic disk device of the present invention, the rewritable nonvolatile memory stores data. The writing means writes the predetermined data read from the magnetic disk in the non-volatile memory. The determination means determines whether or not the read request data from the device on the access side exists in the nonvolatile memory. The reading means reads the data from the non-volatile memory without activating the spindle motor when it is judged by the judging means that the requested data exists in the non-volatile memory and the spindle motor is stopped at this time. Send to the access device side. This allows
It is possible to further reduce the number of rotations of the spindle motor and the rotation time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a magnetic disk device of the present invention. Reference numeral 1 is a CPU that performs various controls of the magnetic disk device 20, 2 is a RAM that stores various data necessary for the CPU 1 to operate, 3 is a ROM that stores various programs that control the CPU 1, and 4 is a magnetic disk A cache memory (DRAM or the like) that serves as a buffer when data is read from 13 is an electrical rewrite that stores data read from the magnetic disk 13 or temporarily stores write data sent from the host computer 30. Possible non-volatile memory,
As shown in FIG. 2, it is assumed that the read area 51 and the write area 52 are divided. Reference numeral 6 is a read / write circuit that controls reading / writing of data from / to the magnetic disk 13 via the head 10, reference numeral 7 is a servo circuit that controls driving of a voice coil motor (VCM) that moves the actuator 11, and reference numeral 8 is a spindle motor. A motor control circuit for controlling ON / OFF and rotation of 15; 9 an interface for connecting the magnetic disk device 20 and the host computer 30; 10 a head for reading / writing data from / to the magnetic disk 13; Attached head 10
An actuator for moving the magnetic disk 13 in the radial direction of the magnetic disk 13, a VCM for rotating the actuator 11,
Reference numeral 14 is a spindle for supporting the magnetic disk 13, 15 is a spindle motor for rotating the spindle 14, 20 is a magnetic disk device constituted by the above-mentioned components, and 30 is a host computer for reading / writing data from / to the magnetic disk device 20. .

Next, the operation of this embodiment will be described. For example, when the system including the magnetic disk device 20 and the host computer 30 shown in FIG. 1 is powered on, the host computer 30 accesses the magnetic disk device 20 to read the startup data. At this time, the host computer 30 determines which logical block (sector)
Whether to access the CPU 1 through the interface 9
Let me know. The CPU 1 uses the motor control circuit 8
The spindle motor 15 is activated to rotate the magnetic disk 13. Along with this, the CPU 1 activates the servo circuit 7 to move the head 10 to the cylinder on the magnetic disk 13 having the sector of the logical block number sent via the interface 9.

The servo circuit 7 controls the VCM 12 based on the information from the CPU 1 and moves the head 10 attached to the tip of the actuator 11 in the radial direction of the magnetic disk 13 to access the target on the magnetic disk 13. The head 10 is positioned on a cylinder having sectors. Thereafter, when the magnetic disk 13 rotates and the target sector on the positioned cylinder comes to the head 10, the CPU 1 reads the data from the head 10 through the read / write circuit 6, and the data is read via the interface 9. And sends it to the host computer 30. At this time, the CPU 1 transfers the read startup data to the read area 51 of the nonvolatile memory 5 shown in FIG.
Write in. CPU 1 is a host computer 30
If there is no access for a predetermined time from, the rotation of the spindle motor 15 is stopped by the motor control circuit 8. afterwards,
When a data read or write request is issued from the host computer 30 via the interface 9, the CPU 1
Restarts the spindle motor 15 by the motor control circuit 8 to rotate the magnetic disk 13.

When the power of the above-mentioned system is once turned off and then turned on again, the host computer 30 requests the CPU 1 via the interface 9 to read data for system startup. At this time, the CPU 1 determines whether or not the data is written in the read area 51 of the non-volatile memory 5, and if the data is written, the start-up data is read from the read area 51, and this is read by the interface 9 To the host computer 30 via. Therefore, at this time, the CPU 1 makes the spindle motor 15
Does not rotate and remains stopped. After that, when a data read / write request is issued from the host computer 30 to the CPU 1 via the interface 9, the CPU 1 activates the spindle motor 15 by the motor control circuit 8 to rotate the magnetic disk 13.

By the way, if the system shown in FIG. 1 is a notebook type personal computer or the like, and a user using this personal computer uses the personal computer only for document creation, Since this personal computer has been started up several times, all the programs required to create a document are stored in the read area 51 of the non-volatile memory 5. Therefore, even in such a case, when the personal computer is started up, the CPU 1 reads the program required for document creation from the read area 51 of the non-volatile memory 5 and sends it to the host computer 30, so that the spindle motor 15 does not rotate. , It is possible to supply the data for starting the document creation function to the host computer 30.

In the magnetic disk device 20 of this embodiment, when a data write request is sent from the host computer 30 to the CPU 1 via the interface 9, the CPU
1 does not write the data sent from the host computer 30 to the magnetic disk 13 immediately by starting the rotation of the spindle motor 15, but sends the data from the host computer 30 to the write area 52 of the non-volatile memory 5. First, write the received data. After that, when the write area 52 of the non-volatile memory 5 becomes full, the C
PU1 is a spindle motor 1 via a motor control circuit 8.
5, the magnetic disk 13 is rotated to read data from the write area of the non-volatile memory 5, and the read / write circuit 6 writes the data from the head 10 onto the magnetic disk 13. Therefore, when the host computer 30 finishes creating a document or the like and saves it in the magnetic disk device 20, it usually fits within 10 Kbytes of a document of about one page. It is possible to save the document in the magnetic disk device 20 without starting up. That is,
When the host computer 30 issues a data write command to the magnetic disk device 20 of this example, if the data to be written is smaller than the capacity of the write area 52 of the non-volatile memory 5, the data is written to the non-volatile memory 5. Since the recording can be performed only on the recording medium, the writing operation can be completed without starting the spindle motor 15.

Next, in the case of a system in which the host computer 30 frequently accesses the magnetic disk device 20,
The CPU 1 buffers the data read from the magnetic disk 13 via the head 10 and the read / write circuit 6 in the cache memory 4 and sends it to the host computer 30. Therefore, the buffered data is read. When a request is made, the data can be immediately read from the cache memory 4 and sent to the host computer 30, and the access time to the magnetic disk device 20 is shortened by this amount. Further, in such a system, when a data write command is sent from the host computer 30, the CPU 1 uses the nonvolatile memory 5 as a write buffer optimized according to the transfer rate of the system.
By using the write area 52, the access from the host computer 30 to the magnetic disk device 20 of the present example is similarly facilitated.

According to the present embodiment, by writing the start-up data when the system is started up in the read area 51 of the non-volatile memory 5, the spindle motor 15 is not rotated from the next start-up. Since the device can be started up only by sending the start-up data stored in the read area 51 of the non-volatile memory 5 to the host computer 30, the number of rotation start-ups of the spindle motor 15 and It is possible to reduce the time during which the spindle motor 15 is rotating.
The power consumption of 5 can be reduced. Therefore, it is possible to use the high-rotation type magnetic disk 20 and shorten the access time to the magnetic disk 20 without shortening the operation time of the entire apparatus when the battery is driven. In a system that frequently accesses the magnetic disk device 20, the write area 52 of the non-volatile memory 5 is operated as a write cache, so that the magnetic disk device 2 is operated.
The performance at the time of writing 0 data can be improved.

[0017]

As described above, according to the magnetic disk device and the data read / write method of the present invention, the power consumption can be reduced by further reducing the number of times the spindle motor is started and the time during which the spindle motor is rotating. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic disk device of the present invention.

FIG. 2 is a schematic diagram showing a configuration example of the nonvolatile memory shown in FIG.

[Explanation of symbols]

1 ... CPU 2 ... RAM 3 ... ROM 4 ... Cache memory 5 ... Non-volatile memory 6 ... Read / write circuit 7 ... Servo circuit 8 ... Motor control circuit 9 ... Interface 10 ... Head 11 ... Actuator 12 ... VCM 13 ... Magnetic disk 14 ... Spindle 15 ... Spindle motor 30 ... Host computer

Claims (5)

[Claims] 1. In a magnetic disk device for reading and writing data on a magnetic disk rotated by a spindle motor, a rewritable non-volatile memory for storing data, and predetermined data read from the magnetic disk for the non-volatile memory. Writing means for writing into the nonvolatile memory, judging means for judging whether or not read request data from the device on the access side exists in the non-volatile memory, and if the request data exists in the non-volatile memory by this judging means. If it is determined that the spindle motor is in a stopped state at this time, the magnetic disk is provided with a reading means for reading data from the non-volatile memory and sending the data to the access device side without activating the spindle motor. apparatus. 2. In a magnetic disk device for reading and writing data on a magnetic disk rotated by a spindle motor, a rewritable non-volatile memory for storing data, and a writing device sent with a write request from an access side device. First, first writing means for writing data to the non-volatile memory, judging means for judging whether or not the non-volatile memory is full, and the judgment means for judging that the non-volatile memory is full. Then,
And a second writing unit that reads data from the nonvolatile memory and writes the data to the magnetic disk after the spindle motor is started by the starting unit. Magnetic disk device. 3. The magnetic disk device according to claim 1, wherein the nonvolatile memory is used as a cache memory for writing when writing data. 4. A magnetic disk device for reading and writing data on a magnetic disk rotated by a spindle motor, wherein predetermined data read from the magnetic disk is stored in a non-volatile memory, and then the predetermined data is read. When there is a request, the data reading method is characterized in that the data is read from a non-volatile memory and sent to an access-side device without rotating the spindle motor. 5. In a magnetic disk device for reading and writing data on a magnetic disk rotated by a spindle motor, write data sent from an access side device is first written into a non-volatile memory, and this non-volatile When the memory is full, the spindle motor is rotated to read data from the non-volatile memory and write the data to the magnetic disk.