JPH10320127A - Storage device with written data protecting function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage device capable of preventing data from being destructed even when a power supply is turned off during the period of data writing using a write cache function by using a back-up power supply having small capacity. SOLUTION: Since only a write cache buffer 4 and a power supply restart request control part 7 are switched to the backup power supply 8 even when a power supply circuit 6 is turned off in data writing, commands and data stored in the buffer 4 can be held. When commands and data are stored in the buffer 4, the control part 7 flashes a buzzy lamp 11 to display a power supply restart request. When the power supply is turned on thereafter, the control part 5 checks the storage of the commands and data in the buffer 4 and writes data in a recording medium 3 again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage device having a write cache function, and more particularly to a storage device for preventing data destruction due to power-off during data writing.

[0002]

2. Description of the Related Art In general, a power supply of a storage device for performing a conventional read / write operation is generally supplied from a power supply of a host.
By turning off the power, the power supply of the storage device is controlled. Therefore, there is a problem in that if the operator erroneously turns off the power of the host while writing to the storage device, the data may be destroyed.

In Japanese Patent Application Laid-Open No. 8-77079, a power-off instruction is invalidated at least until data stored in a write cache buffer in an external storage device is written to a recording medium using a backup power supply. An approach was proposed.

[0004]

In the above-mentioned conventional example,
When data is written by a command from the host, data sent from the host is fetched into the write cache buffer for one day, and thereafter, an operation of actually writing data from the write cache buffer to the recording medium is performed. In a storage device having such a write cache function, the end of writing is indicated to the host when data is taken into the write cache buffer.
Even if the host recognizes that the writing has been completed, the storage device still has a risk of writing before or during writing to the storage medium. If the power is turned off before or during data writing, there is a problem that data is destroyed.

Therefore, Japanese Patent Application Laid-Open No. Hei 8-77079 has proposed a method of invalidating a power-off instruction until data is written to a recording medium. In order to write the data stored in the write cache buffer in the device to the recording medium, a large-capacity backup power supply is required to allow the external storage device to operate sufficiently. There were problems such as the need for an opportunity.

Accordingly, an object of the present invention is to solve the above-mentioned problem by using a small-capacity backup power supply and a storage device which does not cause data destruction even if the power is turned off during data writing using the write cache function. Is to provide.

[0007]

In order to achieve the above object, a storage device with a write data protection function according to the present invention comprises:
In a storage device having a write cache function, a storage medium, a write cache buffer that temporarily stores commands and data in response to a write command to the storage medium, a read / write control unit that controls reading and writing of the storage device, A power supply circuit for supplying a DC output to the storage device, and a backup power supply for supplying a DC output only to the write cache buffer when the power supply circuit is turned off are provided.

When a command and data already exist in the write cache buffer when the power supply circuit is turned on, it is preferable to execute the command in the write cache buffer.

Further, it is preferable to charge the backup power supply while the power supply circuit is on.

Further, when commands and data remain in the write cache buffer when the power supply circuit is turned off, it is preferable to display a power-on request.

A storage device with a write data protection function according to the present invention is, in particular, a storage device having a write cache function, comprising: a storage medium; a write cache buffer for temporarily storing data in response to a write command to the storage medium; A read / write control unit that controls reading and writing of the storage device, a power supply circuit that supplies a DC output to the storage device, and a backup power supply that supplies a DC output to the write cache buffer are provided.

[0012]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a storage device with a write data protection function according to the present invention.
In this device, a host 1 is connected to a storage device 2 and instructs the storage device 2 to read and write data. Further, the AC output a is supplied to the storage device 2. The storage device 2 includes a storage medium 3, a write cache buffer 4 that temporarily stores data in response to a write command to the storage medium 3, and a read / write control unit 5 that controls reading and writing of data in accordance with a command from the host 1. A power supply circuit 6 for supplying a DC output to the storage device 2 by an AC output a; a power supply circuit 6; a write cache buffer 4 and a power-on / request control unit 7 when the power supply circuit 6 is off.
A backup power supply 8 for supplying a DC output only to the power supply, a power supply control unit 9 for controlling the power supply of the write cache buffer 4 and the power supply request control unit 7, a charging circuit 10 for charging the backup power supply 8, and a busy state. Lamp 11
And When the power supply circuit 6 is on, the backup power supply 8 is connected to the charging circuit 10 to perform charging.

Next, the operation of the embodiment of the storage device with write data protection function of the present invention will be described. When the storage device 2 is instructed to write data by the host 1,
Commands and data from the host 1 are temporarily stored in the write cache buffer 4 by the read / write control unit 5, and thereafter, data is written to the storage medium 3. If the power supply circuit 6 is turned off before the data stored in the write cache buffer 4 is written to the storage medium 3, only the write cache buffer 4 and the power-on request control unit 7 use the backup power supply by the power control unit 9. Switch to 8. The write cache buffer 4 holds commands and data stored by the backup power supply 8. In addition, when the command and data are stored in the write cache buffer 4, the power-on / off request controller 7 blinks the busy lamp 11 to display a power-on / off request. After that, when the power is turned on, the read / write control unit 5 confirms that the command and data are held in the write cache buffer 4 and can write data to the recording medium 3 again.

[0015]

As described in detail above, by using the storage device with the write data protection function of the present invention, even if the power is turned off during the writing of data using the write cache, the capacity is small and the size is small. The command and the data stored in the write cache buffer can be held by using a suitable backup power supply, thereby providing an effect of preventing the data from being destroyed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a storage device with a write data protection function of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 host 2 storage device 3 storage medium 4 write cache buffer 5 read / write control unit 6 power supply circuit 7 power supply restart request control unit 8 backup power supply 9 power supply control unit 10 charging circuit 11 busy lamp

Claims (4)

[Claims] 1. A storage device having a write cache function, comprising: a storage medium; a write cache buffer for temporarily storing commands and data in response to a write command to the storage medium; and a read / write control of the storage device. A power supply circuit for supplying a DC output to the storage device; and a backup power supply for supplying a DC output only to the write cache buffer when the power supply circuit is turned off. Storage device with a write data protection function. 2. The command according to claim 1, wherein when the power supply circuit is turned on, if a command and data already exist in the write cache buffer, the command in the write cache buffer is executed. Storage device with write data protection function. 3. The storage device with a write data protection function according to claim 1, wherein the backup power supply is charged while the power supply circuit is turned on. 4. The write according to claim 1, wherein when the power supply circuit is turned off, if a command and data remain in the write cache buffer, a request to turn on the power supply is displayed. Storage device with data protection function.