KR20050113527A - Method for optimizing parameters in data storage unit and disk drive using the same - Google Patents

Abstract

The present invention relates to a parameter optimization method of a data storage device for optimizing parameter values in consideration of a characteristic change with use of a hard disk drive over time, and a disk drive using the same.

The present invention provides a performance evaluation function related to data read for time according to application of each light channel value by sequentially applying a plurality of optimized light channel values and a plurality of light channel values calculated by a matrix combination of light related parameters. (B) from the performance evaluation functions related to the data read for the time according to the application of each light channel value calculated in step (a) related to the data read after the predetermined time according to the application of each light channel value. Predicting a predetermined performance evaluation value, (c) detecting a best performance evaluation value among predetermined performance evaluation values related to data reads after a predetermined time predicted for each light channel value, and (d) comparing the best performance estimate value detected in c) with a predetermined threshold performance estimate value; and (e) the detected If the performance evaluation value of the image is smaller than the predetermined threshold performance evaluation value, the process of bad processing is performed; otherwise, the determination of the light channel parameter values having the best performance evaluation value as the final light channel value to be applied to the disk drive is performed. It is characterized by including.

Description

Method for optimizing parameters in data storage unit and disk drive using the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for determining parameters in a disk drive, and more particularly, to a parameter optimization method of a data storage device for optimizing parameter values in consideration of changes in characteristics over time of use of a hard disk drive, and a disk drive using the same. It is about.

In general, a hard disk drive, which is one of data storage devices, contributes to computer system operation by reproducing data recorded on a disk by a magnetic head or recording user data on the disk. As hard disk drives such as these become increasingly high in capacity, high in density, and small in size, the bit per inch (BPI) in the direction of the disk rotation direction and the track per inch (TPI) in the disk radial direction are increasing. Required.

In order to optimize the performance of recording / reproducing information on the disk of the hard disk drive, various parameters affecting the performance of the hard disk drive are optimized in the burn-in process, which is one of the manufacturing processes. That is, in the burn-in process, values of various parameters corresponding to channel factors for which the characteristics of the read / write channel are optimized are adjusted.

However, as time elapses, a characteristic change (for example, thermal decay) occurs in a disk drive, which causes a read error in the process of reading signals written to a disk of a hard disk drive.

In order to solve this problem, the conventional technique uses a method of increasing the read bias current in order to solve the decrease in B.E.R (Bit Error Rate) performance with the change of characteristics over time. However, this method raises another problem of increasing the electrical stress of the head and shortening the life of the head.

SUMMARY OF THE INVENTION The present invention provides a parameter optimization method of a data storage device and a disk drive using the same for optimizing parameters by predicting a characteristic change over time of a hard disk drive in order to solve the above problems. It is.

In order to achieve the above technical problem, the parameter optimization method of a data storage device according to the present invention is a method of determining a parameter of a data storage device, the method comprising: (a) a plurality of calculated single matrix values and a matrix combination of write-related parameters; Calculating the performance evaluation functions related to data reads with respect to the time according to each light channel value by sequentially applying the two light channel values, (b) the time according to applying each light channel value calculated in step (a) Predicting a predetermined performance evaluation value related to the data read after a predetermined time according to the application of each light channel value from the performance evaluation functions related to the data read for (c) a predetermined time estimated for each light channel value Best performance rating of any given performance estimate related to subsequent data reads. Detecting a value; (d) comparing the best performance evaluation value detected in step (c) with a predetermined threshold performance evaluation value; and (e) the detected best performance evaluation value is determined by a predetermined threshold performance evaluation. If it is smaller than the value, a bad process is performed, and if not, determining the light channel parameter values having the best performance evaluation value as the final light channel value to be applied to the disk drive.

According to another aspect of the present invention, there is provided a disk drive in a data storage device, comprising: a host interface for performing data transmission / reception with a host device, a disk for storing read and write channel parameter values and user data; By sequentially applying a plurality of light channel values calculated by a single optimized read channel value and a matrix combination of light related parameters, performance evaluation functions related to data reads with respect to time according to each light channel value application are calculated and calculated. Predict predetermined performance evaluation values related to data read after a predetermined time for each light channel from the performance evaluation function for each light channel value, and among predetermined performance evaluation values related to data read after a predetermined time predicted for each light channel value. Best performance rating A value is detected, and if the detected best performance value is less than a predetermined threshold performance value, a bad process is performed. Otherwise, the final value of the light channel related parameter values having the best performance value is applied to the disk drive. The controller receives a write channel value and writes the data received through the host interface to the disk by applying the controller and the read and write channel values determined by the controller to control writing to the maintenance cylinder of the disk, or writes data from the disk. And a write / read circuit for performing data processing for reading out.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a configuration of a head disk assembly (HDA) 10 of a hard disk drive to which the present invention is applied.

The head disk assembly 10 includes at least one magnetic disk 12 that is rotated by the spindle motor 14. The disk drive 10 also includes a transducer 16 located adjacent to the disk surface 18.

The transducer 16 can read or write information on the rotating disk 12 by sensing and magnetizing the magnetic field of each disk 12. Typically transducer 16 is coupled to the surface of each disk 12. Although illustrated and described as a single transducer 16, it should be understood that this consists of a write transducer for magnetizing the disc 12 and a separate read transducer for sensing the magnetic field of the disc 12. Read transducers are constructed from Magneto-Resistive (MR) devices. The transducer 16 is also commonly referred to as a head.

The transducer 16 can be integrated into the slider 20. The slider 20 is structured to create an air bearing between the transducer 16 and the surface of the disk 12. The slider 20 is coupled to the head gimbal assembly 22. The head gimbal assembly 22 is attached to an actuator arm 24 having a voice coil 26. The voice coil 26 is located adjacent to the magnetic assembly 28 that specifies the voice coil motor 30 (VCM). The current supplied to the voice coil 26 generates a torque for rotating the actuator arm 24 relative to the bearing assembly 32. Rotation of the actuator arm 24 will move the transducer 16 across the disk 12 surface.

The information is typically stored in an annular track of the disc 12. Each track 34 generally includes a plurality of sectors. Each sector includes a data field and an identification field. The identification field is composed of a gray code identifying a sector and a track (cylinder). The transducer 16 is moved across the surface of the disc 12 to read or write information on other tracks.

The read / write channel parameters, which are data related to the hard disk drive operation, are stored in a maintenance cylinder area, which is a disk area inaccessible to the general user.

2 shows an electrical system 40 capable of controlling a hard disk drive. The electrical system 40 includes a controller 42 coupled to the converter 16 by a lead / right (R / W) channel circuit 44 and a pre-amp circuit 46.

The controller 42 may be a digital signal processor (DSP), a microprocessor, a microcontroller, or the like. The controller 42 controls the read / write channel circuit 44 to read from or write information to the disc 12.

The controller 42 is also coupled to a VCM drive circuit 48 that supplies a drive current to the voice coil 26. The controller 42 supplies a control signal to the VCM drive circuit 48 to control the excitation of the voice coil motor and the movement of the transducer 16.

The memory 50 stores firmware and various control data for controlling the disk drive.

First, the operation of a general disk drive will be described.

In the data read mode, the disc drive amplifies the electrical signal sensed by the transducer 16 from the disc 12 to facilitate signal processing in the preamplifier 46. The read / write channel circuit 44 then encodes the signal read out from the disk 12 into digital signals in accordance with sector pulses generated by the controller 42, converts the signal into stream data, and converts the host interface circuit 54 into a stream signal. To the host device.

Next, in the write mode, the disk drive receives data from the host device through the host interface circuit 54 and temporarily stores the data in an internal buffer (not shown) of the host interface circuit 54, and then stores the data in the buffer. Recorded data amplified by the preamplifier 46 at the time of sector pulse generation after the stored data are sequentially output and converted by the read / write channel circuit 44 into a binary data stream suitable for the recording channel of the disc 12. Current is written to disk 12 via converter 16.

In particular, in the present invention, the controller 42 is a single read channel value and light-related parameters (e.g., write current determination parameters, light precompensation determination parameters and overshoot determinations) optimized in the burn-in test process. Sequentially applying the plurality of light channel values calculated by the matrix combination of parameters) to calculate the performance evaluation functions related to the read of the data written by applying the respective light channel values, and from the calculated performance evaluation function for each light channel value Predict predetermined performance evaluation values related to the data read after the warranty period for each channel, detect the best performance evaluation value among the predetermined performance evaluation values related to the data read after the predicted warranty period for each light channel value, and detect Best performance estimate for this disk drive If it is less than the threshold performance value that can be guaranteed by the disk drive, then the defect is processed. Otherwise, the parameter of the light channel having the best performance value is determined as the final light channel value to be applied to the disk drive. Controls writing to the maintenance cylinder area.

A predetermined performance evaluation item related to the above data read is an example of a B.E.R (Bit Error Rate) evaluation item.

The process of calculating performance evaluation functions (e.g., BER calculation equations over time) related to the read of the data written by applying each light channel value executed in the controller 42 is a single optimized read channel value optimized in detail. And a process of sequentially writing the test data to a predetermined area of the disc by sequentially applying a plurality of light channel values calculated by the combination of the light-related parameter matrix and a single channel value optimized for the test data written with the respective light channel values. The process of repeatedly reading at predetermined time periods (e.g., 30-minute intervals) by applying to measure a predetermined performance evaluation (e.g., BER evaluation) value related to the data read for each period and the measured period The plurality of light channels by analyzing predetermined performance evaluation values related to a star read. Is designed as a process for calculating a predetermined performance evaluation function related to the read of the time when the each application of.

Next, a parameter optimization method of the data storage system under the control of the controller 42 of the disk drive will be described in detail with reference to the flowchart of FIG. 3.

First, a matrix combination of light-related parameters including a single read channel value optimized for the Burn-In test process and the write current determination parameters, the light precompensation determination parameters, and the overshoot determination parameters. The combination table F (i) of the calculated plurality of write channel values is set (S301).

First, the test data is written to a specific area of the disc by applying the light channel values set in the first combination F (1) among the combination table F (i) of the plurality of light channel values (S303).

Then, the test data is repeatedly read for a predetermined number of times at regular time intervals of 30 minutes intervals by applying parameters of the read channel values optimized in the burn-in test process (S304). In an embodiment of the present invention, the number of read repetitions is determined ten times.

While reading data for each period, a bit error rate (B.E.R), which is one of performance evaluation items related to the data read, is measured (S305).

Next, the B.E.R performance evaluation function (equation) for time is analyzed by analyzing the B.E.R value for time per cycle (S306).

BER (i) _Nyear, which is a B.E.R value after N years, is calculated from the B.E.R performance evaluation function calculated in step 306 (S306). Here, it is effective to determine N years as 5 years which is a quality guarantee period as an example.

The BER (i) _Nyear value calculated in step 307 (S307) is stored in the memory 50 (S308).

Then, it is determined whether the value of the combination table F (i) of the currently applied light channel values corresponds to F (max), which is the last combination (S309).

As a result of the determination in step 309 (S309), if the value of the combination table F (i) of the currently applied light channel values does not correspond to the last combination F (max), the write of the next combination table F (i + 1) is performed. After the channel values are applied (S310), steps 303 (S303) to 308 (S308) described above are repeated.

If the value of the combination table F (i) of the currently applied light channel values corresponds to the last combination F (max) as a result of the determination in step 309 (S309), the BER (i) _Nyear values stored in the memory 50 The BER (i) _Nyear_best showing the best performance among the two is detected (S311).

The BER (i) _Nyear_best value detected in step 311 (S311) is compared with a BER_min value, which is a critical performance value that can be guaranteed by the disk drive (S312).

As a result of the determination in step 312 (S312), when the BER (i) _Nyear_best value is smaller than the BER_min value, a bad process is performed (S315). It is expected that the quality of B.E.R after N years (e.g., 5 years), which is a warranty period, will not reach the minimum performance that is guaranteed by the disk drive, which is then treated poorly.

As a result of the determination in step 312 (S312), if the BER (i) _Nyear_best value is greater than or equal to the BER_min value, the light channel parameter values of the light channel of the combination table F (i) that generated the BER (i) _Nyear_best value are optimal. A value is determined (S313), and the determined optimal write channel parameter values are written to the maintenance cylinder of the disk 12 (S314).

In this way, the light channel parameter values can be optimized for the best performance after a certain period of time under the user's conditions of the disk drive.

The invention can be practiced as a method, apparatus, system, or the like. When implemented in software, the constituent means of the present invention are code segments that necessarily perform the necessary work. The program or code segments may be stored in a processor readable medium or transmitted by a computer data signal coupled with a carrier in a transmission medium or communication network. Processor readable media includes any medium that can store or transmit information. Examples of processor-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memory, erasable ROM (EROM), floppy disks, optical disks, hard disks, optical fiber media, radio frequency (RF) networks, Etc. Computer data signals include any signal that can propagate over transmission media such as electronic network channels, optical fibers, air, electromagnetic fields, RF networks, and the like.

Specific embodiments shown and described in the accompanying drawings are only to be understood as an example of the present invention, not to limit the scope of the invention, but also within the scope of the technical spirit described in the present invention in the technical field to which the present invention belongs As various other changes may occur, it is obvious that the invention is not limited to the specific constructions and arrangements shown or described.

As described above, according to the present invention, by optimizing the light channel parameter values such that the performance degradation is minimized over time of the hard disk drive, the effect of increasing the service life of the disk drive is generated and the quality is also improved. The effect can be made.

1 is a plan view of a head disk assembly in a disk drive to which the present invention is applied.

2 is an electrical circuit diagram of a disk drive to which the parameter optimization method of the data storage device according to the present invention is applied.

3 is a flowchart illustrating a parameter optimization method of a data storage device according to the present invention.

Claims (11)

In the parameter determination method of the data storage device, (a) sequentially calculating a plurality of light channel values calculated using a single optimized read channel value and a matrix combination of light-related parameters to calculate performance evaluation functions related to data read over time according to each light channel value application. step; (b) a predetermined performance evaluation value related to data readout after a predetermined time according to the application of each light channel value from the performance evaluation functions relating to data readout with respect to the time according to the application of each light channel value calculated in step (a). Predicting; (c) detecting a best performance evaluation value among predetermined performance evaluation values related to data reads after a predetermined time predicted for each light channel value; (d) comparing the best performance evaluation value detected in step (c) with a predetermined threshold performance evaluation value; And (e) If the detected best performance value is less than a predetermined threshold performance value, a bad process is performed; otherwise, the final light channel to apply the light channel parameter values having the best performance value to the disk drive. And determining the value. The method of claim 1, wherein the predetermined performance evaluation item related to the data read includes a B.E.R (Bit Error Rate) evaluation. The method of claim 1, wherein step (a) (a1) sequentially writing test data in predetermined areas of the disc by sequentially applying a plurality of write channel values calculated by a single optimized read channel value and a matrix combination of write related parameters; (a2) repeatedly reading out the test data written to each of the write channel values in a predetermined time period by applying the optimized single channel value and measuring a predetermined performance evaluation value related to the data read for each cycle; And (a3) calculating a predetermined performance evaluation function related to the read over time for each application of the plurality of light channel values by analyzing the predetermined performance evaluation values related to the read-by-period measured in step (a2). Parameter optimization method of a data storage device, characterized in that it comprises a. 2. The method of claim 1, further comprising writing the write channel parameter values having the best performance evaluation value determined as the final write channel value to a maintenance cylinder of the disc. The method of claim 1, wherein the predetermined time is determined as a quality guarantee period. The method of claim 1, wherein the light-related parameters include a write current determination parameter, a write precompensation determination parameter, and an overshoot determination parameter. In the data storage device, A host interface for performing data transmission / reception processing with the host device; A disk for storing read and write channel parameter values and user data; By sequentially applying a plurality of light channel values calculated by a single optimized read channel value and a matrix combination of light related parameters, performance evaluation functions related to data reads with respect to time according to each light channel value application are calculated and calculated. Predict predetermined performance evaluation values related to data read after a predetermined time for each light channel from the performance evaluation function for each light channel value, and among predetermined performance evaluation values related to data read after a predetermined time predicted for each light channel value. Detects the best performance value, and if the detected best performance value is less than the predetermined threshold performance value, performs bad processing. Otherwise, writes the light channel related parameter values having the best performance value to the disk drive. Final light channel to apply A controller which determines the value and writes it to the maintenance cylinder of the disk; And And a write / read circuit configured to apply the read and write channel values determined by the controller to write data received through the host interface to a disk or to perform data processing for reading data from the disk. Disk drive. 8. The disk drive of claim 7, wherein the predetermined performance evaluation item related to the data read includes a bit error rate (B.E.R). 8. The process of claim 7, wherein the process of calculating performance functions related to data reads over time according to the application of each light channel value comprises: a plurality of light channel values calculated from a matrix combination of optimized single read channel values and light related parameters. Sequentially writing the test data to a predetermined area of the disc by sequentially applying them, and repeatedly reading the test data written to the respective write channel values at predetermined time periods by applying the optimized single channel value. A process for measuring a predetermined performance evaluation value relating to a read of a period and a predetermined performance evaluation value related to the measured read per period to determine a predetermined time related to a read over time for each application of the plurality of light channel values. To calculate the performance evaluation function of Disk drive comprising a disk drive. 8. The disc drive of claim 7, wherein the predetermined time is determined by a quality guarantee period. 8. The disk drive of claim 7, wherein the write related parameter comprises a write current determination parameter, a write precompensation determination parameter, and an overshoot determination parameter.