JPH0520220A - Compact electronic calculator - Google Patents

Abstract

PURPOSE:To suppress the generation of an important error by periodically controlling also the reading of data having low access frequency, and at the time of detecting an error, correcting the error. CONSTITUTION:This compact electronic calculator 1 is provided with a central processing unit(CPU) 2 for controlling normal operation and an error code correcting device 3 having a function for periodically executing reading operation in each previously fixed number of bytes, at the time of generating a correctable reading error, correcting and writing an error generating position by an error correction code and connected to plural disk devices 5 to 7 through an I/O bus 4 for using SCSI standards.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact electronic computing device, and more particularly to a compact electronic computing device using the SCSI standard as an input / output bus.

[0002]

2. Description of the Related Art A conventional small-sized electronic computing device uses, as an input / output bus, a SCSI standard capable of connecting a device having a different interface from a host computer without modifying hardware and software. However, in this case, a dedicated device for coping with the occurrence of a data error is not added.

[0003]

Since the above-mentioned conventional small-sized electronic computing device does not include a dedicated device for dealing with the occurrence of a data error, the recording density increases with the recent technological innovation and the disk device Due to the dramatic increase in capacity, the number of errors that cannot be sufficiently corrected by the conventional correction function using the error correction code is increasing. However, these errors include many cases that can be corrected if they are minor, but if you do not access this for a long time, a read error will occur due to microdust. There is a possibility that
In the above-mentioned conventional small-sized electronic computing device, for data that is rarely accessed, the read operation is performed only when the data is needed, and it is known that a serious error occurs for the first time. There is a problem that it is loose and is easily affected by microdust.

An object of the present invention is to carry out read control even for data that is rarely accessed, and to correct when an error is detected, so that the occurrence of a serious error can be suppressed. To provide a device.

[0005]

A small electronic computer according to the present invention uses an SCS as an input / output bus for a plurality of disk devices.
Using the I standard, a read operation was periodically performed by a predetermined number of bytes for all areas of the plurality of disk devices connected to the input / output bus, and a correctable read error occurred by an error correction code. In this case, an error correction code correction device having a function of correcting and writing a portion where an error has occurred is provided.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

The small electronic computer 1 of the present invention performs a read operation periodically with a central processing unit 2 for controlling a normal operation and a predetermined fixed number of bytes to generate a correctable read error by an error correction code. In this case, an error correction code correction device 3 having a function of correcting and writing a location where an error has occurred is provided, and connected to a plurality of disk devices 5, 6, 7 via an input / output bus 4 using the SCSI standard. is doing.

Next, the operation will be described.

During normal operation, the central processing unit 2 intermittently issues a command to any one of the disk devices 5, 6 and 7. On the other hand, the error correction code correction device 3
Attempts to acquire the input / output bus 4 in order to periodically perform a read operation on the disk devices 5, 6, 7. At this time, the selection order of the error correction code correction device 3 is set to the lowest compared to the other devices connected to the input / output bus 4, so that the central processing unit 2 uses the input / output bus 4. The I / O bus 4 can be acquired only when there is not. When the bus is acquired, the error correction code correction device 3 issues a read command to any one of the disk devices 5, 6, 7 such as the disk device 5. If a correctable error due to the error correction code is detected, it is corrected and the corrected data is written in the same area. At this time, it is necessary to take care so that the central processing unit 2 does not operate the same disk device 5 between the read and the write.

Next, the error correction code correction device 3 performs a read operation for the next area after a certain period of time. In this way, when the read operation for the entire area of the disk device 5 is completed, the disk device 6 and the disk device 7 also read.

[0012]

As described above, according to the present invention, the SCSI standard is used as an input / output bus with a plurality of disk devices, and a predetermined constant is set for all areas of the plurality of disk devices connected to the input / output bus. When a correctable read error due to an error correction code occurs by performing a read operation periodically for each number of bytes of the There is an effect that it is possible to suppress the occurrence of a serious error by periodically performing read control even for data that is infrequent and correcting it when an error is detected.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

 1 small electronic computer 2 central processing unit 3 error correction code correction device 4 input / output bus 5, 6, 7 disk device

Claims (1)

Claim: What is claimed is: 1. A compact electronic computing device that uses the SCSI standard as an input / output bus to and from a plurality of disk devices,
An error occurs when a read error that can be corrected by an error correction code occurs by periodically performing a read operation for every predetermined number of bytes on all areas of the plurality of disk devices connected to the input / output bus. A small-sized electronic computing device comprising an error correction code correction device having a function of correcting and writing the above-mentioned portion.