JPH03280201A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To previously prevent the generation of a clash or the like by recording previously set check data in a contact area with a magnetic head, reading out the check data and inspecting the damaged state of the contact area based upon the data. CONSTITUTION:In the stopped state of disk rotation, a magnetic head 27 comes into contact with the disk 28 in a CSS zone 13. When a power supply is turned on and the disk 28 reaches its steady rotation, a CPU 24 reads out the check data 17 recorded in the zone 13 and compares the read check data 17 with data stored in a memory 25. The memory 25 stores the same data as the check data 17 in the CSS zone 13 obtained at the time of shipment for instance. Thereby when the CSS zone 13 is in a normal state, the check data 17 read out from the zone 13 coincide with the data stored in the memory 25. If a difference more than a prescribed level exists between both the data, the CPU 24 judges as an abnormal state and generates an alarm signal to a host device 21.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is directed to the recording of data using a recording medium having a contact area with a magnetic head such as a C5S (contact start/stop) system. The present invention relates to a magnetic disk device that performs recording/reproduction.

(Prior Art) Conventionally, in hard disk drives, for example, C8S is used to keep the magnetic head close to the innermost circumference of the recording medium that is not used for recording/reproducing data when accelerating, decelerating, and stopping the recording medium. There are contact areas called zones. Normally, no servo data is written in this contact area, and when the magnetic head is located in this area, the AGC
An error or the like is detected, and it is detected that the magnetic head is in an area where there is no servo data.

(Problems to be Solved by the Invention) Incidentally, in a recording medium having a contact area as described above, damage to the contact area is naturally the most severe among the recording media. Severe damage to the contact area can lead to, for example, a crash. However, since there is no way to check for wear, damage, or dust on the recording medium within a magnetic disk drive, there is a problem in that it is not possible to inspect the damage state of the contact area, making it impossible to prevent worst-case situations such as crashes. Ta.

The present invention has been made in view of the above points, and an object of the present invention is to provide a magnetic disk device that can easily inspect the damage state of the contact area of a recording medium with a magnetic head and can prevent crashes and the like. purpose.

[Configuration of the Invention (Means and Effects for Solving the Problems) That is, the magnetic disk device according to the present invention records preset check data in a contact area with a magnetic head, and when the magnetic head The check data is read out when the contact area is in the contact area, and the damage state of the contact area is inspected based on the data to generate, for example, a warning signal.

According to such a configuration, the state of the contact area, which is most severely damaged in the recording medium, can be easily inspected based on the check data, thereby making it possible to prevent crashes and the like.

(Embodiment) Hereinafter, a magnetic disk device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a servo surface in a servo surface servo system. In FIG. 1, arrows indicate the outer circumferential direction, and arrow B indicates the inner circumferential direction. This servo surface has a data zone 11 and a guard band zone 1 from the outer circumference to the inner circumference.
2. C8S zone J3 is provided. The data zone 11 and guard band zone 12 include a sync clock 14, sync data 15 and servo data 16a,
16b is recorded in a predetermined format. The sync clock 14 is information for detecting sync data 15. The sink data 15 is the servo data 16a
This is information for opening a window that reads %16b. The servo data 16a and 16b are information for head positioning control.

Guard band zone I2 is an area indicating the end of data zone 11. Further, the C5S zone 13 is provided at the innermost circumference, and is an area on which the magnetic head contacts and slides when the recording medium is accelerated, decelerated, and stopped. Here, in the same embodiment, preset check data 17 is recorded in the C5S zone 13. This check data 17 is information for checking the damage state of the C8S zone 13.

FIG. 2 is a block diagram showing the configuration of the control system of the same embodiment. In the same embodiment, the magnetic disk device includes a magnetic disk controller (hereinafter referred to as HDC) 22 and a magnetic disk drive (hereinafter referred to as HDD) 23.

The IDC 22 is a CPU that has a CPU 24 and a memory 25, and exchanges data with the host device fIt21.
Reference numeral 24 controls the entire magnetic disk device, and here performs damage inspection processing as shown in FIG. 3 or FIG. 4. Comparison data for checking the validity of the check data F recorded in the C8S zone 13 in FIG. 1 is recorded in the memory 25. Also, HDD
23 has an R/W circuit 26, a magnetic head 27, and a disk 28, and records/reproduces data under the control of the HDC 22.

Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG.

Before the power is turned on, that is, when the rotation of the recording medium is stopped, the magnetic head is in contact with the recording medium in the C8S zone 13 shown in FIG. Here, when the power is turned on and the recording medium reaches steady rotation (step AI), the CPU
24 reads the check data 17 recorded in the C5S zone 13 and compares the read check data 17 with the data in the memory 25 (steps A2 to A4).
). For example, the same data as the check data 17 of the C8S zone 13 at the time of shipment is recorded in the memory 25. Therefore, if the C8S zone 13 is in a normal state, the check data 17 read from the C8S zone 13 will match the data in the memory 25.

Therefore, by comparing the two data, the CPU 24 determines that there is an abnormal state if there is a difference of more than a predetermined level, generates a warning signal to the host device 21, and then starts a first seek (step A5, A6).

In this way, the condition of the C8S zone 13, which is the most severely damaged among the recording media, is inspected based on the check data 17, and a warning signal is generated in case of abnormality. Therefore, it is possible to know when to replace the recording medium by this warning signal, and it is possible to prevent a crash or the like from occurring by exchanging the recording medium.

Note that in the above embodiment, when an abnormality in the C5S zone 13 is detected, startup is not immediately canceled; however, this means that when the C8S zone 13 is abnormal, the magnetic head is
This is because it is safer to deal with the problem after moving it to an area other than Zone 13.

Further, in the above embodiment, data for comparison is stored in the memory 25 in advance, and using this data, the C8S zone 1
Although the validity of the check data 17 recorded in 3 is checked, the validity can also be checked, for example, by reading out the check data 17 for one round as shown in FIG.

FIG. 4 is a flowchart for explaining the operation according to another embodiment of the present invention. After the power is turned on, when the recording medium reaches steady rotation, the CPU 24 reads the check data 17 stored in the C8S zone 13 for one round, and compares each piece of data constituting the check data 17 for one round (step B1 ~B4). For example, if there is a scratch in the C8S zone 13, the data in the scratched portion has a lower voltage level when read than other data. Therefore,
The CPU 24 compares each piece of data constituting the check data 17 for -cycles, and if it detects data with a difference of more than a predetermined level, it determines that it is in an abnormal state,
Start a fast seek after raising a warning signal (
Steps B5, B6).

In this way, the validity of the check data 17 can be checked and the damage state of the C8S zone 13 can be inspected without referring to the contents of the memory 25. Further, in the above embodiment, a C5S type recording medium is described in which a contact area with a magnetic head is provided on the innermost periphery, but the present invention is not limited to the C8S type. A recording medium provided with a contact area can also be inspected for damage using a similar method. Further, the same applies not only to the servo surface servo method but also to, for example, the data surface servo method.

[Effects of the Invention] As described above, according to the present invention, it is possible to easily inspect the condition of the contact area, which is most severely damaged in a recording medium, based on a check mark, thereby preventing crashes and the like. It is something that can be done.

[Brief Description of the Drawings] Fig. 1 is a diagram showing the configuration of a recording medium according to an embodiment of the present invention, Fig. 2 is a block diagram showing the configuration of a control system of the embodiment, and Fig. 3 is a diagram showing the configuration of a control system of the embodiment. Flowchart for explaining the operation of the example. FIG. 4 is a flowchart for explaining the operation according to another embodiment of the present invention. II...Data zone, +2...Gart band zone, 13...C8S zone, 14...Sync clock, 15...Sync data, lea and 18b...Servo data, 17...Chiku data , 21... host device, 22... HDC, 23... HDD.

Claims (1)

[Scope of Claims] A recording medium having a contact area with a magnetic head, in which check data set in advance is recorded, and when the magnetic head is in the contact area of the recording medium. 1. A magnetic disk drive comprising: inspection means for reading check data and inspecting the damage state of the contact area based on the data.