JPS6031064A - Start inspecting system of magnetic disc apparatus - Google Patents

Abstract

PURPOSE:To enhance the reliability of a disc, by performing cleaning operation on the basis of the seek operation of a magnetic head prior to writing or reading operation, and detecting the presence or absence of a writing and reading error after sweeping off dust accumulated on a disc. CONSTITUTION:When operation is started after long-time stoppage, a rotation order signal is sent to a spindle motor 12 from a power source circuit part 4 and a disc 10 performs steady rotation. A seek operation order is applied to a positioning apparatus 8 by the order of a processor and dust accumulated on the disc 10 is swept off out of the magnetic disc 10 by a head 9. When seek operation is finished, the magnetic head 9 receives positional determination on the examination diagnostic track of the magnetic disc 10 by the order of a positioning circuit part 7. The collation with writing data is performed in a control circuit part 5 and the presence or absence of writing and reading errors is detected. As mentioned above, because the presence or absence of the writing and reading errors is detected to enable confirmation, the reliability of the disc can be kept.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a start-up test method for a magnetic disk drive, and more particularly to a start-up test method for a sealed magnetic disk drive in which a magnetic disk and a magnetic head are housed in a sealed container.

Magnetic disk drives used as external storage devices for computer systems are required to have high reliability and durability, and as the recording density increases, these demands are becoming stronger. To this end, various improvements have been made, such as improving the characteristics of the magnetic disk itself, which is a recording medium, and improving its structure to prevent damage caused by dust. In particular, in recent years, magnetic disk drives have been designed to improve the reliability of such recording falsification, imprinting, and reading operations.
A magnetic disk and a magnetic head that writes and reads information on the magnetic disk are housed in a sealed container, and the temperature rise in the sealed container due to air resistance caused by the rotation of the magnetic disk is reduced by air flow inside the sealed container. So-called sealed magnetic disk drives have become mainstream, and have a structure that maintains the reliability of information writing and reading by suppressing the natural circulation or forced circulation by blowing clean air from outside.

During operation of the magnetic disk drive described above, the temperature inside the sealed container rises and the internal pressure becomes high, but when the operation is stopped, the temperature falls and the internal pressure also becomes low. To compensate for this drop in internal pressure, in magnetic disk drives using a natural circulation method, all breathing vents equipped with dust removal filters are used to supply air from the outside, and in magnetic disk drives using a forced circulation method, air is supplied from the outside. External air is supplied from the inlet or outlet of the air circulation path.

For this reason, the air in the sealed container may be mixed with incompletely removed air, and in such cases, when restarting the operation of the magnetic disk drive after a long period of suspension, for example at the end of the year. When using a magnetic disk drive after a New Year's holiday or a long consecutive summer holiday, the dust in the sealed container that accumulated on the magnetic disk surface during the idle period may get caught between the magnetic head and the magnetic disk, causing the magnetic disk drive to This changes the flying posture of the magnetic disk, causing write or read errors and sometimes damage to the magnetic disk surface (head crash). This phenomenon is particularly noticeable in forced circulation type magnetic disk drives that have many air circulation lids.

Therefore, an object of the present invention is to provide a magnetic disk drive that can remove dust accumulated on a magnetic disk when starting up a magnetic disk drive after a long-term suspension, and further inspect the presence or absence of dust attached to a magnetic head by the dust removal operation. It is an object of the present invention to contribute to maintaining and improving the reliability of magnetic disk drives by providing a startup testing method for disk drives.

The recording method of the uninvented magnetic disk device rotates the magnetic disk at a predetermined number of rotations in response to a startup operation start command.
Next, the magnetic head is caused to perform a seek operation in a predetermined seek mode, and after the seek operation is completed, the magnetic head is positioned on the inspection/diagnosis track of the magnetic disk, and then the magnetic head is used to perform the inspection/diagnosis track. The method includes writing test data on a diagnostic track, then reading out all of the written test data using the magnetic head, and comparing and verifying the written test data and the read data. Ru.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a complete block diagram showing the configuration of an example of a magnetic disk device to which the start-up test method of the present invention is applied. The magnetic disk device, which is an example of a magnetic disk device, exchanges write/read information 21. Control signal 22. It is connected to a host device by an interface section 2 that exchanges address information 23 and status information 24, and a power control interface section 3 that operates upon receiving a power control instruction signal 25 from the host device. Inside the magnetic disk device, there is a control circuit unit 5 that sends and receives control signals 32 to and from the interface unit 2.
, a write/read circuit unit 6 that exchanges write/read information 31 with the interface unit 2 while exchanging a write/read control signal 33 with the control circuit unit 5; and a positioning control signal 34 from the control circuit unit 5. It also receives a positioning address signal 35vi from the interface section 2 and operates. Positioning circuit section 7 equipped with magnetic head 9
a positioning device 8 which receives a servo signal 41 and sends out a speed signal 42; and a magnetic disk 10 on which information is written and read by a magnetic head 9. ffl ki disk 1 (
A rotation control signal 45 is sent to the spindle motor 12 for one rotation.
f. A power supply control circuit unit 4 is provided which operates upon receiving a power supply control signal 36 from the sending power supply control interface unit 3. The magnetic head 9 and the magnetic disk 10 are housed in a sealed container, blocked from air flow to the outside, and protected from contamination by dust.

In the magnetic disk device configured as described above, during normal operation, the magnetic disk 10 is rotated steadily by the spindle motor 12 that rotates in response to commands from the power supply control circuit section 4. The positioning device 8 is positioned on a predetermined track by a command from the positioning circuit section 7, and the magnetic head 9 writes information 6- or moves the information through the write/read circuit section 6 and the interface section 2. Information is exchanged with the host device.

When such a magnetic disk drive stops operating for a long period of time, such as during the year-end and New Year holidays, as mentioned above, fine dust contained in the outside air for breathing into the sealed container, Dust remaining in the air circulating inside the magnetic disk device accumulates on the surface of the magnetic disk 10. Therefore, when the pause period expires and the operation is resumed, the accumulated dust is caught between the magnetic head 9 and the magnetic disk 10, causing the magnetic field to change the flying posture of the disk 9. Write/read errors may occur. Therefore, in order to prevent such errors, when restarting the operation, the start-up operation is performed using the start-up inspection method of the present invention, an embodiment of which is shown in FIG.

In other words, when starting operation after a long period of cessation,
A start-up operation start command is given to the power supply control circuit section 4 (by receiving a start-up command signal as a power control command signal 25 from a higher-order VET or by pressing a start-up button equipped in a magnetic disk device). 51) Then, the power supply control circuit section 4 sends a rotation command signal to the spindle motor 12, and the spindle 12 and the magnetic disk 10 perform steady rotation (reference number 52), and then the positioning circuit section 7
The positioning device i
Since the seek operation command is given to [8, the positioning device [8
performs a seek operation on the magnetic disk 10 (reference number 53). In this seek operation, the magnetic head moves from the innermost cylinder (largest cylinder) to the outer circumference one cylinder at a time, and the magnetic head is positioned on each cylinder for more than one rotation. The seek mode (so-called decrement seek mode) that moves from the outermost cylinder (0 cylinder) to the innermost cylinder (maximum cylinder) is effective, but the It is possible to use an appropriate seek operation such as a repeat seek mode in which the cylinders are moved back and forth between the cylinders, or a random seek mode in which an arbitrary cylinder is selected every two times. Through this seek operation, the dust accumulated on the magnetic disk 10 is swept out of the magnetic disk by the magnetic head 9.

When the seek operation for cleaning is completed, the positioning device 8 positions the magnetic head 9 on the inspection/diagnosis rack (hereinafter referred to as TdD) rack of the magnetic disk 10 according to a command from the positioning circuit section 70 (reference number 54). ,T(HD)
A rack is a special track provided on each magnetic disk recording surface of a magnetic disk drive. It is not used for normal data storage or reading, but is used for inspection to test the magnetic disk drive or diagnose failures. Alternatively, it is a track used exclusively for writing and reading diagnostic data.

When the magnetic head 9 is positioned above TdD),
9 writes test data sent from the host device or test data stored in the read-only memory built in the control circuit section 5 (reference number 55) to the magnetic field. , Subsequently, this written test data is read out by reference number 9-56), and the read test data is read out by the interface section 2.
The data is sent to a higher-level device via the controller and compared with the written data, or is compared with the written data within the control circuit section 5 (reference numeral 57) to check whether there is an error in writing or reading. If there is a reading error, the cause will be investigated and removed.

The above-mentioned start-up inspection operation can be performed entirely by commands from the host device, but the control unit 5 is provided with a dedicated memory for storing the above-mentioned operation procedure, and the microprocessor in the control circuit unit 5 It is also possible to perform the operation by giving commands to the power supply control circuit section 4 and the positioning circuit section 7 while reading the operating procedure from this read-only memory. In addition, the initial rotation of the magnetic disk (reference number 52) may be made to perform steady rotation at the same number of rotations as when performing normal writing or reading, but the power supply control circuit section 4 A motor rotation control unit configured to be able to command steady rotation (e.g. 3600 rl) m) and low speed rotation (e.g. -10 = e.g. 3000 rl)' with a rotation speed lower by a predetermined ratio than the steady rotation. The motor may be provided and the motor may be rotated at low speed in response to a command from the motor rotation control section.

At this time, the flying height of the magnetic head 9 is lower than the flying height during normal rotation (the rotational speed during low-speed rotation is set so that the flying height is the optimum flying height for the cleaning operation), and therefore the magnetic head 9 Dust on the magnetic disk is effectively swept away by the seek operation (reference number 53).

Furthermore, when the magnetic disk stops rotating, the magnetic head remains stationary in contact with the surface of the magnetic disk, and as the rotational speed of the magnetic disk increases, it floats up, and the rotational speed of the magnetic disk remains constant. In the case of a magnetic disk drive using the so-called contact start-stop method (C8S method), which is configured to maintain a flying distance of one foot by rotating, the magnetic head is activated after the seek operation (reference number 53) of the magnetic head. Return the spindle motor 12 and the magnetic disk 1 to the contact start/stop area (an area on the magnetic disk when the magnetic head comes into contact with the magnetic disk and comes to rest; this is usually called the C8S zone). (l After stopping the rotation operation according to a command from the power supply control circuit section 4, the rotation operation is started again by a command from the power supply control circuit section 40 to perform steady rotation at the redundant number of rotations υ, and then the T of the magnetic head is
It is also possible to perform a positioning operation (reference number 54) on the dD track. By stopping the rotation of the magnetic disk and re-rotating it, the magnetic disk comes into contact with the surface of the magnetic disk and then resurfaces. If there is any remaining dust, the dust is removed by force, so that the dust can be removed more reliably.

As explained in detail above, by using the startup inspection method of the magnetic disk device of the present invention, when restarting operation after a long period of suspension, the magnetic disk drive is After cleaning the dust accumulated on the magnetic disk by performing a cleaning operation using the seek operation of the magnetic disk drive]
You can check and check for errors, so
This has the effect of maintaining the reliability of the magnetic disk drive and reducing damage to the magnetic disk surface (head crash) caused by dust adhering to the magnetic head.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an example of a magnetic disk device to which the present invention is applied, and FIG. 2 is a flowchart of an embodiment of the present invention. In the figure, 2... Interface section, 3... Power supply interface section, 4... Power control circuit section, 5
...Control circuit section, 6...Write/read circuit section, 7...Positioning circuit section, 8...
・Positioning device, 9...Magnetic head, 10...
...magnetic head, 12... spindle motor. da 7 lo

Claims (1)

[Claims] The magnetic disk is rotated at a predetermined number of revolutions by a startup operation start command, and then the magnetic head is caused to perform a seek operation in a predetermined seek mode, and after the seek operation is completed, the magnetic head is used for inspection and diagnosis of the magnetic disk. Tiger,
Then, the magnetic head is used to perform the inspection and inspection.
writing test data on a diagnostic track, then reading the written test data with the magnetic head;
A start-up test method for a magnetic disk device, comprising comparing and verifying the written test data and the read data.