JPH02154359A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent the remaining of any sector required for rewrite of data by providing a voltage maintaining means capable of allowing a write processing by one sector even when a power input is cut off and a control means for stopping the write processing at a sector partition point when an abnormality of a power supply voltage is detected. CONSTITUTION:The subject device is provided with a voltage maintaining circuit 4 for assuring continuation of the write processing at least by one sector even when the power input is cut off and a control part 5 for stopping the write processing at the sector partition point when abnormality of the power supply voltage is detected. Then, even when a detecting signal is generated from a voltage drop detecting circuit 3 in the midst of a write operation for a sector, this operation is not immediately stopped, but the operation is continued until the write operation for this sector is completed receiving the power source to be maintained by an operation of the voltage maintaining circuit 4, and the operation is stopped upon completion. By this method, no sectors required for rewrite of data are remained at all.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, and particularly to a control technique when an abnormality in power supply voltage occurs such as a power outage.

[Prior Art] As is well known, many magnetic disk devices perform read/φ write processing using a sector set on a disk as the first processing unit.

Additionally, conventional devices are configured to immediately stop operating if the power supply voltage drops abnormally due to the power plug being accidentally removed or a power outage occurring during operation.

FIG. 3(a) shows a functional block diagram of a conventional magnetic disk device as an example. In the figure, the read/write logic (10) is the logic for reading and writing data, and the head positioning logic (11) is the logic for reading and writing data. is the logic that positions the magnetic head (not shown) at a predetermined position, the spindle motor control logic (12) is the logic that controls the rotation of the magnetic disk (not shown), and the device abnormality detection logic (13) is the logic that controls the rotation of the magnetic disk (not shown). The logic for detecting an abnormality, the power supply abnormality detection logic (14), is the logic for detecting a voltage abnormality in the disk device.

In addition, in FIG. 3(b), the power supply voltage abnormality signal (17
) is a falling signal indicating an abnormality in the power supply voltage.

Next, the operation will be explained. In FIG. 4, the magnetic disk has multiple sectors on the track, sector 0 (15a
), sector 1 (15b), sector 2 (15c)・
... Sector pulses (15a) and (15b) that are divided into sectors n and indicate the starting point of each sector.
, (15c) (however, the starting point of sector O (16a) is given by index pulse (18)).

When writing data, sector pulses (15a), (15
b) , (15c)... or index pulse (
18), the data is written to the data area (16) of the sector and stored.

When the power supply voltage drops during data writing (when the power supply voltage abnormality signal (17) falls), the power supply abnormality detection logic (14) operates even within the data area, as shown in FIG. A voltage abnormality signal (17) is generated, the device abnormality detection logic (13) is activated, and the disk device immediately stops writing data.

The conventional technology regarding this type of magnetic disk device is as follows.
It is shown in Japanese Patent Application Laid-Open No. 61-269271.

[Problems to be Solved by the Invention] A situation where the operation stops due to a voltage drop can naturally occur even during a write operation. Since the write operation is executed with one sector as a processing unit, if the write operation is interrupted in the middle of a sector, it is necessary to newly rewrite the data of the entire sector. Therefore, when the power supply voltage is restored, in order to check whether there was a sector where the write operation was interrupted, it is a hassle to read the data, compare it with the original data (the data you were trying to write), and rewrite if there is an error. Additional post-processing was required.

This invention was made in view of the conventional problems mentioned above.The purpose of this invention is to prevent the magnetic field from leaving sectors that require data rewriting even if the write operation is interrupted due to a voltage drop in the power supply voltage. The purpose is to provide disk devices.

[Means for Solving the Problems] Therefore, in the present invention, in a magnetic disk device that performs read/write processing in sector units, a voltage is set to ensure that write processing for at least one sector continues even if power input is cut off. A holding means and a control means for stopping write processing at a sector division point when an abnormality in the power supply voltage is detected are provided.

[Operation] Even if power input is cut off during a write operation for a certain sector, normal operation continues until the write operation for that sector is completed by the voltage holding means. Further, when the write operation for the sector in the middle of writing is completed, the control means stops the operation at the sector division point without proceeding to the write operation for the next sector.

[Embodiment] As shown in FIG. 1, operating power for each part of the magnetic disk drive main body (1) is supplied from a power supply circuit (2). The power supply circuit (2) is a circuit that converts power input into a predetermined power output, and includes a voltage drop detection circuit (3) for detecting that the voltage on the input side has become below a standard, and A voltage holding circuit (4) is attached to keep the voltage on the output side within the normal range for a certain period of time even if the voltage on the output side falls below the standard. Here, the fixed period of time refers to the magnetic disk device itself (
1) is the time required to perform write processing for at least one sector.

The control unit (5) in the magnetic disk device main body (1) is for overall control of each part of the device, and also controls to stop the operation of the device in response to a detection signal from the low voltage detection circuit (3). The control unit (5) performs this. The read/write circuit (6) is a circuit that exchanges read/write signals with the head (not shown), and during read/write operations, control signals such as sector synchronization signals obtained from the head are read/write. The light is supplied from the light circuit (6) to the control section (5).

As shown in Figure 2, each time the head access point reaches the first sector of the track, the index pulse (
18) is generated and a sector pulse (15) is generated as each subsequent sector in that track is reached. The index pulse (18) and sector pulse (15) are referred to herein as a sector synchronization signal. Read/write operations are performed in sector units according to this synchronization signal.

Further, in the magnetic disk device according to the present invention, the control unit (5
) does not stop its operation immediately even if a detection signal is supplied from the voltage drop detection circuit (3) during a write operation, and then performs sector synchronization from the read/write circuit (6) as shown in Figure 2. The operation is stopped at the timing when the signal is supplied.

In other words, even if a detection signal is generated from the voltage drop detection circuit (3) during a write operation to a certain sector, the operation is not stopped immediately, but the operation is continued using the power maintained by the action of the voltage holding circuit (4). , continues the operation until the write operation for that sector is completed, and then stops the operation. Therefore, the write operation for the next sector does not proceed.

[Effects of the Invention] As explained above in detail, in the magnetic disk drive according to the present invention, even if the power source voltage drops during a write operation, one sector is maintained by the power source maintained by the voltage holding means. The operation continues until the write operation is completed.
Furthermore, the operation is stopped at the sector division point without proceeding to the next write operation. Therefore, there are no sectors that require data rewriting, and the troublesome post-processing required in the past is no longer necessary.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of the main parts of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a timing chart showing its operation, and FIG. 3(a) is a schematic block diagram of the main parts of a conventional magnetic disk device. Block diagram, Fig. 3(b), Fig. 3(a)
FIG. 4 is a timing chart showing the operation of a conventional magnetic disk device. In the figure, (1) is the main body of the magnetic 'F disk device, (2)
(3) is a voltage drop detection circuit, (4) is a voltage holding circuit, (5) is a control section, and (6) is a read/write circuit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. 7 Ritsu Tree 4 India book 4eaA Ishikame Tensk Jf [#7” Mouth ゛ν Book All 1 Shame λ Task Value 1 tie? 7t Te v-1 Figure 1 Figure 2 Figure Imashiba East 2. Ishihagi Ki Te 2 Scroll! Diagram Procedural Amendment (Voluntary) 2. Name of Invention Magnetic Disk Device 3. Representative Moriya Shiki 4. To Agent Index 0 Rus Diagram 5. Amendment Detailed explanation of the invention in the subject specification, column for brief explanation of drawings, and drawings. 6. Contents of amendment Stone aeration device

Claims (1)

[Claims] In a magnetic disk device that performs read/write processing in sector units, there is a voltage holding means to ensure that write processing continues for at least one sector even if power input is cut off, and a sector A magnetic disk device comprising: control means for stopping write processing at a dividing point.