JPH01277372A - Input/output control device - Google Patents

Abstract

PURPOSE:To easily and surely inspect the correctness of data written in a recording medium and to improve the reliability of data to be recorded by reading out data written in an I/O device by a comparing means and comparing the read data with data stored in a data buffer memory. CONSTITUTION:When the quantity of data to be recorded is larger than the capacity of a data buffer memory 2, new data are substituted for the initial data. Since the length of data to be compared with a comparator 5 has been already set up in a counter 7 by a CPU 10, access check is executed and the comparator 5 starts to compare the data stored in the memory 2 with data read out from a magnetic disk. At the time of detecting the discrepancy (error) of the data, the comparator 5 informs the error to the CPU 10. Then, the data recorded in the magnetic disk are transferred to the host side through a data buffer register 9. Consequently, the correctness of data written in the recording medium can be easily and surely inspected.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an input/output control device.

(Prior Art) In recent years, storage devices using recording media such as optical disks and magnetic disks from which data can be read and written have become widespread.

For example, in a hard disk type magnetic disk device, these magnetic disks, which are recording media of 3, 5 inches, 5.25 inches, 8 inches, etc., are stacked at intervals. Data is written by a magnetic head arranged in correspondence with the magnetic head.

By the way, verification of the correctness of data written on each magnetic disk is generally performed by the CRC or ECC check function of the controller.

(Problem 8 to be solved by the invention) However, when verifying the correctness of data written on a magnetic disk using the CRC or ECC check function of the controller, it is not possible to check data that is not related to these functions. As a result, verification of the correctness of the data becomes incomplete.

In this case, data written on the magnetic disk can be read and verified, but if a large amount of data is to be verified, a large capacity buffer memory is required.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide an input/output control device that can easily and reliably verify the correctness of data written on a recording medium.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, an input/output control device of the present invention has an input/output control device having a data buffer memory for temporarily storing data to be written to the input/output device. When verifying whether data has been correctly written to the input/output device in the control device,
Comparing means for reading data written to the input/output device and comparing it with data stored in the data buffer memory;
A flag means for permitting the comparison means to compare, a setting means for setting the start position of the data to be compared and setting the flag means at this start position, and a setting means for setting the length of the data to be compared and setting the data of this data length. After the comparison is finished,
and reset means for resetting the flag means.

(Function) In the input/output control device of the present invention, data written to the input/output device by the comparing means can be read and compared with data stored in the data buffer memory.

(Example) Hereinafter, details of an example of the present invention will be described based on the drawings.

FIG. 11 is a block diagram of a control section showing an embodiment in which the present invention is applied to a magnetic disk device.

As shown in the figure, the control unit includes a data buffer memory 2 for temporarily storing data from the host via a data buffer register 1, and a data buffer memory 2 for writing data from the data buffer memory 2 to a magnetic disk (not shown). A data buffer register 3 and a data buffer register 4 for reading data from a magnetic disk are provided.

The control unit also includes a comparator 5 that compares the contents of the data buffer memory 2 with data read from the magnetic disk.
Counter 6 and comparator 5 that specify the data comparison start position
Counter 7 and Counter 6 specify the data length to be compared.
and a flag setting unit 8 for setting a flag in the comparator 5 based on the value of the counter 7, a data buffer register 9 for transferring data read from the magnetic disk to the host,
A CPU 10 is provided to control the operation of each component.

The control section having such a configuration performs the following operations.

First, when a write command is output from the host to the magnetic disk, data to be recorded on the magnetic disk is temporarily stored in the data buffer memory 2 via the data buffer register 1. Next, data buffer memory 2
The data stored in is written to the magnetic disk via the data buffer register 3. Here, the data buffer memory 2 is a FIFO (First In First
t0ut) Since the amount of data to be recorded is larger than the capacity of the data buffer memory 2, the first data is replaced with new data.

At this time, the length of the data to be compared in the comparator 5 has already been set in the counter 7 by the CPU 10, and the start position of the data to be compared has been set in the counter 6.

At this time, a call check is performed, and when the counter 6 counts up to the specified position, cPUlo sets the flag setting section 8. Thereby, the comparator 5 starts comparing the data stored in the data buffer memory 2 and the data read from the magnetic disk.

When the data to be compared reaches the specified length, the flag setting section 8 is reset by the CPU 10, and the operation of the comparator 5 is stopped. Further, when the comparator 5 detects a data mismatch (error), it notifies the CPU 10 of the error.

Thereafter, when a read command is output from the host to the magnetic disk, the data recorded on the magnetic disk is transferred to the host via the data buffer register 9.

Note that for data exceeding the capacity of the data buffer memory 2, a normal CRC or FCC check is performed.

In this way, in this embodiment, the data recorded on the magnetic disk and the data stored in the data buffer memory 2 are compared by the comparator 5, so that the reliability of the data to be recorded on the magnetic disk is improved. can be done.

In this embodiment, a case has been described in which the present invention is applied to a magnetic disk device, but the present invention is not limited to this example, and may be applied to other storage devices using recording media such as optical disks.

[Effects of the Invention] As explained above, according to the input/output control device of the present invention, it is possible for the comparison means to read the data written to the input/output device and compare it with the data stored in the data buffer memory. Therefore, it is possible to easily and reliably verify whether the data written on the recording medium is correct, thereby improving the reliability of the data to be recorded.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control section showing an embodiment in which the present invention is applied to a magnetic disk device. 1.3.4...Data buffer register, 2...Data buffer memory, 5...Comparator, 6...Counter, 7...Counter, 8...Flag setting section, 9...
- Data buffer register, 10...cpu. Applicant Toshiba Corporation Representative Patent Attorney Sasa Suyama −

Claims (1)

[Claims] (1) In an input/output control device that has a data buffer memory that temporarily stores data to be written to an input/output device, when verifying whether data has been correctly written to the input/output device, a comparison means for reading the stored data and comparing it with the data stored in the data buffer memory; a flag means for permitting the comparison by the comparison means; and a start position of the data to be compared is set, and the start position of the data is set and a setting means for setting the flag means;
An input/output control device comprising: reset means for resetting the flag means after a length of data to be compared is set and data comparison of this data length is completed.