JPH0376047A - Disk breakdown preventing device - Google Patents

Abstract

PURPOSE:To eliminate the need of such a work as a periodical replacement of a battery, etc., and also, to manufacture the device at a low cost by executing the backup at the time of abnormality of a power source by a capacitor only during the necessary minimum period without using the battery. CONSTITUTION:When an AC input 25 from an AC power source 23 is stopped by interruption or power failure, etc., abnormality is generated in a DC output 14 of a first power unit 13. A power source abnormality detecting circuit 15 detects it, and sends out a detecting signal 32 of a high level to a stop control circuit 17. In such a case, normally, a DC output 24 of a second power unit 22 also becomes abnormal, but since a capacitor 21 contained in this second power unit 22 executes immediate backup, a normal state can be maintained. As for this capacitor 21, it is required to have minimum capacitance to supply normal DC current only for a write time. In such a way, such a work as a periodical replacement of a battery, etc., becomes unnecessary, and also, the device can be manufactured at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to disk destruction prevention, which prevents information on a disk device from being destroyed due to power failure of an information processing device having a disk device as an external storage device. Regarding equipment.

[Conventional technology]

Generally, information processing apparatuses that require large external storage memories often include disk devices such as magnetic disks. In this type of information processing equipment, if a power failure occurs while data is being written to the disk device, a write error occurs in the area being written, and this is further detected as an information error in the disk device itself, so the information processing system as a whole This will develop into a disability.

For this reason, conventionally, in advanced information processing equipment, there has been a method of making the entire system uninterrupted by battery backup, or a method of performing battery backup of only a part of the equipment as proposed in Japanese Patent Application No. 63-162408. This prevents the data on the disk device from being destroyed.

[Problem to be solved by the invention]

In such conventional devices, for example, the former method in which the entire device is backed up by a battery has the drawback of requiring a large and very expensive power supply device. Furthermore, even in the case of a partial battery backup method such as the latter, a specially designed power supply device is required, resulting in an increase in cost.

Furthermore, these battery backup systems also have the problem of requiring periodic replacement due to the lifespan of the battery.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a disk destruction prevention device that does not require periodic battery replacement and can be manufactured at low cost.

[Means to solve the problem]

The present invention includes (i) a data write operation detection means for detecting a data write operation performed by a disk controller on a disk device; and (ii) a period from the time when a power supply abnormality occurs until the end of the data write operation. a power supply unit equipped with a capacitor that continues to output direct current; (iii) a power supply abnormality detection means that monitors this power supply unit and detects abnormalities; (iv)
) At the time when this power supply abnormality detection means detects a power supply abnormality, if the data write operation detection means detects a data write operation, after the completion of that operation; if not, at the time when a power supply abnormality occurs. The disk destruction prevention device is provided with a stop control means for stopping the operation of the disk control device.

In the present invention, a capacitor with a built-in power supply is used as a drive source after a power failure occurs, and the disk is controlled until the data writing operation is completed at the time of the power failure. If no write operation is being performed, immediate disk control will be stopped.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 1 shows a disk control device and peripheral devices in an embodiment of the present invention.

This disk control device 11 is equipped with a power supply abnormality detection circuit 15 that monitors the DC output 14 of the first power supply device 13 that supplies DC current to the central processing unit 12 and detects an abnormality. It is connected to one of the input terminals of a stop control circuit 17 that determines whether or not to stop the operation.

Disk device 1 connected to this disk control circuit 16
8 is also connected to a data write operation detection circuit 19 that detects whether a data write operation is being performed between them. The output side of this data write operation detection circuit 19 is connected to the other input terminal of the stop control circuit 17.

The output side of this stop control circuit 17 is connected to the disk control circuit 16.

The disk control device 11 and the disk device 18 are operated by DC current 24 supplied from a second power supply device 22 containing a capacitor 21 . The second power supply device 22 and the first power supply device 13 each convert AC human power 25 from the same AC power supply 23 into DC current.

Next, the operation of the disk control device configured as above and its peripheral devices will be explained.

The disk control circuit 16 writes and reads data to and from the designated area in the disk device 18 according to instructions from the central processing unit 12, but only the write operation will be explained here and the read operation will be omitted. .

First, a data write operation in a normal power supply state will be explained.

FIG. 2 shows the chronological flow of the data write operation.

When a data write command 31 is output from the central processing unit 12, the disk control circuit 16 decodes it and sends the designated write area information and data to the disk device 18. The disk device 18 includes a write head (not shown) (hereinafter simply referred to as a head).

) to the track where the specified area exists. The time required for this operation is the seek time T1, which is the longest among the write operations, and also consumes a large amount of current.

When the head reaches the target track, the magnetic storage medium waits for rotation until the target area on the track moves to the position of the head.

This is the rotation waiting time T2, which ends when the writing start position is detected. Therefore, the maximum time required is approximately one rotation.

When the head detects the write start position, the designated data is written. The time required for this is write time T3, which is an extremely short time in the series of operations. However, if a momentary power interruption or power outage occurs during this time T3, abnormally shaped information will be written on the magnetic storage medium.

Therefore, data on the disk can be prevented from being destroyed by protecting the power supply so that it continues to output a normal DC current at least during this time T3.

Next, the operation when a power supply abnormality occurs will be explained.

When the AC power supply 25 from the AC power supply 23 stops due to a momentary interruption or power outage, the DC output 1 of the first power supply bag [113]
An abnormality occurs in 4. The power supply abnormality detection circuit 15 detects this and sends a high level detection signal 32 to the stop control circuit 17. At this time, the DC output 24 of the second power supply device 22 would normally become abnormal, but the capacitor 21 built into the second power supply device 22 immediately performs backup, so the normal state can be maintained. I can do it.

This capacitor 21 only needs to have a capacity sufficient to output a normal DC current only during the above-mentioned write time T3.

On the other hand, the data write operation detection circuit 19 constantly monitors the write operation from the disk control circuit 16 to the disk device 18, and sends a frontage-level detection signal to detect that the data write operation is being performed. 33, otherwise a high level signal is supplied to the stop control circuit 17.

Therefore, by ANDing the detection signal 32 and the detection signal 33, the stop control circuit 17 performs the data writing operation to the disk device 18 when both are at high level, that is, when an abnormality occurs in the DC output 14. If not, the stop control circuit 17 outputs a high level control signal 3.
4 to the disk control circuit 16. As a result, the disk control circuit 16 immediately gives a stop instruction to the disk device 18.

Furthermore, when a data write operation is being performed on the disk device (2) 8 at the time when an abnormality occurs in the DC output 14, the stop control circuit 17 supplies a low level control signal 34 to the disk control circuit 16.

As a result, the disk control circuit 16 issues a stop instruction to the disk device 18 after normally completing the minimum unit write operation currently being performed. This results in
Finish the write operation normally.

As described above, according to the present embodiment, the DC current output from the capacitor 21 built into the second power supply device 22 allows the operation to be completed normally even when a power supply abnormality occurs.

〔Effect of the invention〕

As explained above, according to the disk expansion prevention device of the present invention, backup in the event of a power failure is performed only for the minimum necessary period using a capacitor without using an expensive battery, so that the battery can be replaced regularly. It has the advantage that it does not require such operations and can be manufactured at low cost.

[Brief explanation of drawings]

The drawings are for explaining one embodiment of the present invention. Among them, Fig. 1 is a block diagram showing a disk destruction prevention device and its peripheral devices, and Fig. 2 is a block diagram showing a write operation to a disk device. FIG. DESCRIPTION OF SYMBOLS 11... Disk control device, 12... Central processing unit, 13... First power supply device, 15... Power supply abnormality detection circuit, 16... ... Disk control circuit, 17 ... Stop control circuit, 18 ... Disk device, 19 ... Data write operation detection circuit, 21 ...
... Capacitor, 22 ... Second power supply device, 23 ... AC power supply.

Claims (1)

[Scope of Claims] A data write operation detecting means for detecting a data write operation performed by a disk controller on a disk device, and a means for detecting a data write operation performed by a disk controller; a power supply section including a capacitor that continues to output; a power supply abnormality detection means for monitoring the power supply section and detecting an abnormality; It is characterized by comprising a stop control means that stops the operation of the disk control device after the end of the data writing operation when the means detects the data writing operation, and at the time when a power supply abnormality occurs when the means does not detect the data writing operation. Disk destruction prevention device.