KR100568422B1 - Read data error correction method - Google Patents

Abstract

end. The technical field to which the invention described in the claims belongs:

A technique related to error correction in a data recording and reading device.

I. The technical problem the invention is trying to solve:

It provides an error correction method that increases error correction capability but hardly increases the probability of error correction.

All. The gist of the solution of the invention:

The present invention performs error correction by determining an error of original data using ECC (Error Correction Code) when reading data from a data recording and reading device such as an HDD. First, error correction is performed without maximizing ECC capability. This reduces the likelihood of miscorrection and, in the case of continuous ECC errors, reduces the occurrence of ECC errors by maximizing ECC capacity.

la. Important uses of the invention:

Hard disk drive

Description

Read data error correction method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data recording and reading devices, and more particularly to a method for correcting errors in data read in data recording and reading devices, such as a hard disk drive (hereinafter referred to as "HDD").

These days, data storage and reading devices are rapidly increasing in capacity in response to the multimedia implementation of the system, and are being developed to enable high-speed data access. One example of such a data storage and reading device is a hard disk drive (HDD). The HDD is widely used as an auxiliary memory device of a computer system due to the advantage of enabling high-speed data access and high capacity.

Data storage and reading devices such as HDDs use codes called error correction codes (ECCs) to detect and correct errors in data when reading data. Disk controller chip companies design error correction circuits with several levels of ECC capability (ie error correction capability) in hardware, but do not use the maximum ECC capability in use. This is because there is a disadvantage in that the probability of miscorrection is increased by using a large ECC capability. The meaning of the miscorrection is to determine that the data is normally read without knowing that an ECC error or correction is incorrect. This is a fundamental characteristic of ECC.

As a result, drive companies with low data error rates lower ECC capabilities, reducing the chance of false positives. Reducing the probability of miscorrection while lowering ECC capability is fatal, because the greater the probability of miscorrection, the less likely it is for recovering the read data.

Accordingly, it is an object of the present invention to provide an error correction method that increases error correction capability but hardly increases the probability of error correction.

In accordance with the above object, the present invention, in the data recording and reading apparatus, the error correction is performed by using the ECC (Error Correction Code) to read the data to perform error correction, the error without first maximizing the ECC capability Correction is performed to reduce the possibility of miscorrection, and if ECC errors continue to occur, the ECC error is reduced by maximizing the ECC capability.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same elements in the figures are denoted by the same numerals wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a block diagram of an HDD that is an example of a data recording and reading apparatus for better understanding of the present invention. Referring to FIG. 2, the disks 10 are rotated by a spindle motor 34. Each of the heads 12 is located on the corresponding one of the disks 10, and the disks 10 from the E-block assembly 14 coupled with the rotary voice coil actuator 30. It is installed to correspond to each of the support arms extending to the side. The preamplifier 16 preamplifies the signal picked up by one of the heads 12 at the time of read, and applies the analog read signal to the read / write channel circuit 18. The coded write data applied from the read / write channel circuit 18 is written onto the disc through the corresponding one of the heads 12. The read / write channel circuit 18 detects and decodes a data pulse from the read signal applied from the preamplifier 16 and applies the read / write channel circuit 18 to the DDC (Disk Data Controller) 20, and writes the write data applied from the DDC 20. Decode and apply to preamplifier 16. The DDC 20 writes data received from the host computer via the read / write channel circuit 18 and the preamplifier 16 to the disk or reads data from the disk and transmits the data to the host computer. The DDC 20 also interfaces the communication between the host computer and the microcontroller 24. The buffer RAM 22 temporarily stores data transmitted between the host computer and the microcontroller 24 and the read / write channel circuit 18. The microcontroller 24 controls track search and track following in response to a read or write command received from the host computer. The memory 26 stores the execution program of the microcontroller 24 and various setting values. The servo driver 28 generates a driving current for driving the actuator 30 in response to a signal for controlling the position of the heads 12 provided by the microcontroller 24 and applies it to the voice coil of the actuator 30. do. The actuator 30 moves the heads 12 on the disks 10 in correspondence with the direction and level of the drive current applied from the servo driver 28. The spindle motor driver 32 rotates the disks 10 by driving the spindle motor 34 according to a control value for the rotation control of the disks 10 generated from the microcontroller 24.

2 is a flow chart of a data error correction control of a data recording and reading apparatus according to an embodiment of the present invention. In order to increase the ECC capability and not increase the probability of miscorrection, the ECC capability is lowered in the first few retries and continuously corrected. If this is not the case, try again using the maximum ECC capability to reduce ECC errors.

Hereinafter, the data error correction operation in the data recording and reading apparatus will be described in detail with reference to FIGS. 1 and 2. The microcontroller 24 is provided in the read / write channel circuit 18 in step 100 to set the ECC capability value to a value lower than the ECC capability maximum value in the error correction circuit, and performs data read in step 102. In step 104, it is checked whether the read data is an error (the probability of miscorrection is high). If not, the process proceeds to step 116 to report the current error correction is in a good state.

However, if a data error occurs in the determination in step 104, the process proceeds to step 106 and the data read is retried a number of times. If the data is not recoverable, go to step 116 to report the current error correction as good.

However, if it is determined that the data recovery is impossible in step 108, the process proceeds to step 110, the ECC capability of the error correction circuit unit is set to the maximum value, and the process proceeds to step 112 to retry the data read. Thereafter, in step 114, it is determined whether an error has occurred in the data read by retry. If no error has occurred, the process proceeds to step 116 and reports a good error correction state. However, if an error occurs in the data read by the retry, the process proceeds to step 118 and reports an error correction failure state.

In the above description of the present invention, specific embodiments have been described, but various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be defined by the equivalent of claims and claims.

As described above, the present invention performs error correction by determining an error of original data using ECC (Error Correction Code) when reading data from a data recording and reading device such as an HDD. Correction is performed to reduce the possibility of miscorrection, and if ECC errors continue to occur, the ECC error is reduced by maximizing the ECC capability.

1 is a block diagram of an HDD that is an example of a data recording and reading apparatus for helping understanding of the present invention;

2 is a data error correction control flowchart according to an embodiment of the present invention.

Claims (1)

In the data error correction method in the data recording and reading device, Performing a data read several times by setting up data error correction to an error correction capability value at least less than the maximum error correction capability; If the read data is in a recoverable state, reporting an error correction good state; If the read data is in an unrecoverable state, retrying to read data by setting up data error correction to the maximum value of the error correcting capability; And reporting an error correction good state if no error occurs in the data read by the retry, and reporting an error correction bad state if an error occurs in the data read by the retry.