JP2000057060A - Storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage device for which initialization is not required. SOLUTION: This storage device has a data holding part for holding data, a write register table 2 to register write when data are written in this data holding part and to be cleared by an initializing instruction and an output data selecting part 3 for outputting data in the data holding part when write is registered in the write register table at the time of reading and outputting an initialize value when write is not registered in the write register table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage device that does not require initialization.

[0002]

2. Description of the Related Art In many storage devices, an error detection function is added to a data portion. Therefore, if the initialization pattern is not written, an abnormality will occur when reading the data portion to which nothing has been written yet.

Therefore, in a conventional storage device, a specified initialization pattern is written in all data sections by an initialization command.

[0004]

In recent years, with the increase in the capacity of a storage device, a great deal of time has been spent writing an initialization pattern in a data portion.

Also, in a storage device using a medium having a limited number of erasures, such as a flash memory, which has a feature that data cannot be written unless data once written is erased, initialization performed once is performed. The pattern needs to be erased before the next writing, and has been shortened to its life.

An object of the present invention is to realize a storage device that does not require initialization.

[0007]

According to the present invention, in a storage device for storing data, a data holding unit for holding the data, and when data is written in the data holding unit, the data is written and registered, and an initialization command is written. When the write registration table is cleared, the data of the data holding unit is output when there is write registration in the write registration table, and when there is no write registration in the write registration table, the initialization value is set. And an output data selection unit for outputting.

According to the present invention, the write registration table is cleared by the initialization command, and is written and registered when data is written to the data holding unit. Then, at the time of reading, the output data selection unit outputs the data of the data holding unit when there is a write registration in the write registration table, and outputs the initialization value when there is no write registration in the write registration table.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of the present invention. In the figure, a data holding unit 1 holds data in response to a write request, outputs data when there is no error in the data in response to a read request, and outputs an error notification when there is an error in data.

The write registration table 2, for example, a nonvolatile storage element, is written and registered by the data holding unit 1 when data is written to the data holding unit 1 for each storage unit of the data holding unit 1, and initialized. Cleared by instruction.

When a write request is received in the write registration table 2 upon receiving a read request, the output data selection unit 3 outputs data or an error notification from the data holding unit 1 and outputs the data to the write registration table 2. If there is no write registration, the initialization value (initialization pattern) is output.

The operation of such a device will be described below.
By the initialization command, the entire write table 2 is initialized (cleared), and the data holding unit 1 is registered as a state in which data has not been written after the initialization.

Thereafter, when data is given by a write request, the data holding unit 1 holds the data.
At the same time, the data holding unit 1 notifies the writing table 2. As a result, the write registration table 2 performs write registration at a location corresponding to the location held by the data holding unit 1.

In response to a read request, the data holding unit 1 outputs data when there is no error in the data, and outputs an error notification when there is an error in the data.
Then, the output data selection unit 3 determines that the write registration has been performed based on the registration information in the write registration table 2.
It outputs data from the data holding unit 1 or an error notification, and outputs an initialization value if write registration has not been performed.

As described above, the write registration is performed by the write registration table 2, and the output data selection unit 3 outputs the data of the data holding unit 1 or the initialization value based on the information of the write registration table 2. It is not necessary to initialize the data holding unit 1. Thus, the time required for initializing a large-capacity storage device can be reduced.

In addition, when used in a storage device using a medium having a limited number of erasures, for example, a flash memory, data cannot be written unless data once written is erased. Since writing is not performed on the medium, the life can be prevented from being shortened due to initialization.

The output data selection unit 3 outputs an error notification based on the write registration table 2, so that
When outputting the initialization value, it is possible to prevent the error notification from being output.

The present invention is not limited to this, and may be as follows. Although the output data selection unit 3 selects whether or not to output an error notification based on the write registration table 2, the data holding unit 1
However, the configuration may be such that the data is directly output based on the write registration table 2 without going through the output data selection unit 3. That is, the data holding unit 1 outputs an error notification when there is an error in the data and there is a write registration in the write registration table 2 in response to the read request, and outputs an error notification when there is no write registration. Do not output.

The data holding unit 1 notifies the writing registration table 2 of writing, and the writing registration table 2
Although the configuration for performing the write registration has been described, a configuration in which the write request is directly input to the write registration table 2 and the write registration is performed at a location corresponding to the location where the data holding unit 1 holds the data may be adopted.

The output data selector 3 reads the registration information from the write registration table 2. However, the output data selector 3 inputs a read request directly to the write registration table 2, and outputs the registration information to the output data selector 3. A configuration for notifying may be used.

[0021]

According to the present invention, the following effects can be obtained. According to claim 1, the writing registration table allows
Since the write registration is performed and the output data selection unit outputs the data of the data holding unit or the initialization value according to the information of the writing registration table, the data holding unit does not need to be initialized. Thus, the time required for initializing a large-capacity storage device can be reduced.

In addition, when used in a storage device using a medium having a limited number of erasures, for example, a flash memory, data cannot be written unless data once written is erased. Since writing is not performed on the medium, the life can be prevented from being shortened due to initialization.

According to the second aspect, the error notification is output based on the write registration table. Therefore, it is possible to prevent the error notification from being output when outputting the initialization value.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

[Explanation of symbols]

 1 data holding unit 2 write registration table 3 output data selection unit

Claims (2)

[Claims] 1. A storage device for storing data, comprising: a data holding unit that holds the data; and a write registration table that is written and registered when data is written in the data holding unit, and is cleared by an initialization command. At the time of reading, when there is a write registration in the write registration table, the data in the data holding unit is output; and when there is no write registration in the write registration table, an output data selection unit that outputs an initialization value. A storage device comprising: 2. The storage device according to claim 1, wherein when there is a write registration in the write registration table and an error is found in the data in the data holding unit, an error occurrence notification is made.