KR20080072211A - Adaptive channel parameter optimization method and apparatus and disk drive using same - Google Patents

Abstract

The present invention relates to a method and apparatus for setting parameter optimization applied to a data storage system, and more particularly, to a method and apparatus for adaptively optimizing channel parameters of a disk drive.

In the adaptive channel parameter optimization method according to the present invention, a variable range is set so that a parameter value for generating divergence at the time of channel optimization is not included for each parameter, and an optimum value is changed while changing an initial value of a corresponding parameter within the set variable range. Determining a parameter value for generating a channel characteristic of and storing the determined optimal parameter value as a value to be actually applied of the corresponding parameter.

Description

Method and apparatus for adaptive channel parameter optimization and disk drive using the same {Method and apparatus for optimizing adaptive channel parameter and disk drive using the same}

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

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

3 is a block diagram of an apparatus for adaptive parameter optimization according to the present invention.

4 is a flowchart of an adaptive parameter optimization method according to the present invention.

The present invention relates to a method and apparatus for setting parameter optimization applied to a data storage system, and more particularly, to a method and apparatus for adaptively optimizing channel parameters of a disk drive.

In general, a hard disk drive, which is one of data storage devices, contributes to computer system operation by reproducing data recorded on a disc by a magnetic head or by recording user data on the disc. As such hard disk drives are gradually increasing in capacity, density, and miniaturization, bit per inch (BPI) in the direction of disk rotation and track per inch (TPI) in the radial direction are increasing, so a more sophisticated mechanism is required. do.

In the burn-in process, which is one of the disc drive manufacturing processes, channel parameters are optimized according to characteristics of a head which records / reproduces information on a disc. That is, in the burn-in process, each channel parameter value is changed for each head, and the value of the read / write channel is optimized and determined as the parameter value of the corresponding channel.

If the channel parameters are out of a certain range, the channel characteristics do not optimize and divergence occurs. In addition, other parameters may also affect and diverge.

However, in the related art, regardless of the model of the disk drive produced in the burn-in process, each channel parameter value is switched within the same range while finding a value that generates optimum performance. That is, in the case of using the same channel chip, regardless of the model of the disk drive, as an example, a parameter value for generating optimal performance while varying from 0x00h to 0xFFh is determined.

Accordingly, according to the related art, since a variable range of parameters cannot be set differently according to the model characteristics of a disk drive produced at the time of channel optimization, divergence occurs at some parameter values during channel optimization, resulting in data read / write performance. There was a problem of deterioration.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an adaptive channel parameter optimization method for preventing divergence during channel optimization by adaptively limiting a variable range for parameter optimization and a disk drive using the same. have.

In order to achieve the above technical problem, the adaptive channel parameter optimization method according to the present invention includes setting a variable range such that parameter values for generating divergence at the time of channel optimization are not included for each parameter; Determining a parameter value generating an optimal channel characteristic while changing an initial setting value, and storing the determined optimal parameter value as a value to be actually applied of the corresponding parameter.

In an embodiment of the present invention, the variable range is determined as a minimum value and a maximum value, and the minimum value and the maximum value are preferably stored in different registers.

In accordance with another aspect of the present invention, there is provided an apparatus for optimizing adaptive channel parameters according to an embodiment of the present invention, including: a first register storing an initial setting value for each parameter for determining channel characteristics; and a parameter value for generating divergence during channel optimization for the parameter. A second register for storing the minimum value of the variable range set to not be included, a third register for storing the maximum value of the variable range, and a parameter value stored in the first register is applied to the read / write channel circuit to initialize the system. In the channel optimization mode, the channel performance is evaluated by varying a value of the parameter applied to the read / write channel circuit within a range between a value stored in the second register and a value stored in the third register. Determine the value that generates the performance as the optimal value for the parameter It is characterized in that it comprises a parameter optimization control.

In one embodiment of the present invention, it is preferable to further include a fourth register for storing the optimum value of the parameter.

Disc drive according to the present invention in order to achieve the above another technical problem is a disk for storing information, a read for performing data write and read processing for writing data to the disk, or to restore the data read from the disk Memory stored in the memory and the variable range information configured to not include an initial setting value and a parameter value generating divergence during channel optimization for each parameter for determining channel characteristics of the read / write channel circuit and the read / write channel circuit. Initialize the system by applying each initial setting value as the parameter value of the read / write channel circuit, and adjust the channel performance while varying the values of the parameter applied to the read / write channel circuit within the variable range in the channel optimization mode. To evaluate, optimal To determine a null value that causes the performance to the optimum value of that parameter it characterized in that it comprises a system control unit for storage in the memory.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the drawings.

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

Hard disk drives consist of a combination of electrical circuits and a head disk assembly (HDA) consisting of mechanical components.

1 shows a configuration of a head disk assembly (HDA) 10 of a hard disk drive to which the present invention is applied. HDA 10 includes at least one magnetic disk 12 that is rotated by spindle motor 14. HDA 10 also includes a transducer (not shown) located adjacent to the disk surface.

The transducer can read or write information on the rotating disk 12 by sensing and magnetizing the magnetic field of each disk 12. Typically the transducer is coupled to each disk surface. Although described as a single transducer, it consists of a write transducer (aka writer) for magnetizing the disc 12 and a separate read transducer (aka reader) for sensing the magnetic field of the disc 12. It must be understood. Read transducers are constructed from Magneto-Resistive (MR) devices.

The transducer may be integrated into the magnetic head 16. The magnetic head 16 is structured to create an air bearing between the transducer and the surface of the disk 12. The magnetic head 16 is integrated into the head stack assembly (HSA) 22. The head stack 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 to specify a 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 across the disk 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 a servo field. A preamble, a servo address / index mark (SAM / SIM), a gray code, and a burst (A, B, C, D) signal are recorded in the servo field. The transducer is moved across the disk surface to read or write information on other tracks.

2 shows an electrical system 40 capable of controlling a hard disk drive according to the present invention. The electrical system 40 includes a system control 42 coupled to the magnetic head 16 by a lead / right (R / W) channel circuit 44 and a preamplifier 46.

The system controller 42 may be a digital signal processor (DSP), a microprocessor, a microcontroller, or the like. The system control unit 42 reads / writes the information from the disk 12 or writes the information to the disk 12 according to a command received from a host device (not shown in the drawing) via the host interface circuit 54. The write channel circuit 44 is controlled.

The system controller 42 is also coupled to a voice coil motor (VCM) driver 48 that supplies a drive current to the voice coil 26. The system controller 42 supplies a control signal to the VCM driver 48 to control the movement of the magnetic head 16.

The ROM 50 stores firmware and channel parameter information for controlling the disk drive. In particular, the ROM 50 stores variable range information set such that an initial setting value and a parameter value for generating divergence during channel optimization are not included for each parameter for determining channel characteristics of the read / write channel circuit 44.

Here, examples of the parameters include the coefficients of the low pass filter constituting the read / write channel circuit 44, the number of taps and the coefficients of the FIR filter, and the like.

The variable range that does not include the initial setting value for each parameter and the parameter value that causes divergence during channel optimization can be obtained experimentally at the disc drive design stage.

For reference, the generation of divergence during channel optimization refers to a state in which the optimization variable is not found while continuously performing the optimization process when the channel optimization process is applied by applying a corresponding parameter value. In this state, even though the parameter is reset within the normal range through repeated optimization, other parameter values are out of the normal range, resulting in the overall channel divergence.

The ROM 50 also stores programs for executing the flowchart of the adaptive channel parameter optimization method according to the present invention shown in FIG. 4.

When power is supplied to the disk drive, the RAM 52 is loaded with disk drive information read from a maintenance cylinder position of the disk 12.

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 reading element of the magnetic head 16 from the disc 12 by a fixed gain value in the preamplifier 46. Then, after performing the automatic gain control, the read / write channel circuit 44 converts the signal read out from the disk 12 into a digital signal according to the sector pulse generated by the system control unit 42, and then decodes it. The decoded data is subjected to error correction processing using Reed Solomon code as an example in the system control unit 42, and then converted into stream data and transmitted to the host device through the host interface circuit 54.

Next, in the write mode, the disk drive receives data from a host device (not shown) through the host interface circuit 54, and the system controller 42 generates a parity symbol for error correction by the Reed Solomon code. The recording element of the magnetic head 16 with the write current amplified by the preamplifier 46 at the time when the sector pulse is generated after the encoding process suitable for the recording channel by the read / write channel circuit 44. The disc 12 is written to.

Next, an adaptive channel parameter optimization apparatus according to the present invention will be described with reference to FIG. 3.

As shown in FIG. 3, the apparatus for adaptive channel parameter optimization according to the present invention includes a parameter optimization controller 310, a plurality of register blocks 320, and a ROM 50.

Here, the plurality of register blocks 320 are configured in detail with the first, second, third and fourth registers 320-1, 320-2, 320-3, and 320-4.

The parameter optimization controller 310 and the plurality of register blocks 320 of the above configuration means are circuit configurations built in the system controller 42 of FIG. 2. Of course, in some cases, it may be designed separately from the system control unit 42, but it is efficient to incorporate the system control unit 42.

The parameter optimization controller 310 reads out an initial setting value from the ROM 50 for each parameter to be optimized before executing the channel optimization mode and stores it in the first register 320-1. That is, when a command for executing channel optimization is received from the host interface circuit 54, the parameter optimization controller 310 before the channel optimization mode is executed, the parameter optimization initial value for each parameter to be optimized in the ROM 50. The data is read and stored in the first register 320-1 (R _dft ).

In addition, the parameter optimization controller 310 reads out the minimum value of the variable range set from the ROM 50 so that the parameter value for generating divergence during channel optimization for the parameter to be optimized is not included in the second register 320-2. ; R _min ).

The parameter optimization control unit 310 reads the maximum value of the variable range set from the ROM 50 so that the parameter value for generating divergence during channel optimization for the parameter to be optimized is not included in the third register 320-320. 3; R _max ).

In this way, after the preparation for channel optimization, the parameter optimization controller 310 executes the channel optimization mode.

That is, the parameter optimization controller 310 sequentially orders the corresponding parameter value stored in the first register 310-1 between the minimum value stored in the second register 310-2 and the maximum value stored in the third register 320-3. The channel performance is evaluated after being applied to the read / write channel circuit 44 after varying. As an example, the channel performance may be evaluated by obtaining a bit per error rate (BER) according to test data write / lead.

The parameter optimization controller 310 finds a parameter value that generates the best channel performance among the parameter values stored in the second register 310-2 and the third register 310-3, and then optimally applies the parameter to the parameter. Determined by the value.

The optimal value of the parameter determined as described above is stored in the ROM 50.

After executing the channel optimization mode, when the disk drive is initialized, the parameter optimization controller 310 reads out the optimum value of the corresponding parameter stored in the ROM 50 and stores the optimal value in the fourth register 310-4 (R _verif ). The parameter value is applied to the actual read / write channel circuit 44.

The above channel optimization process is performed in a burn-in process, which is one of the manufacturing processes of a disk drive.

According to an embodiment of the present invention, the variable range information set so that the ROM 50 does not include an initial setting value for each parameter and a parameter value for generating divergence upon channel optimization and an optimum value for each parameter determined through the parameter optimization process are stored. However, in some cases, instead of the ROM 50, it may be stored in a maintenance cylinder (commonly referred to as MC) area, which is a system area inaccessible to the user of the disk 12.

Next, the adaptive channel parameter optimization method according to the present invention will be described in detail in time series with reference to the configuration diagrams of FIGS. 2 and 3 based on the flowchart of FIG. 4.

First, the system controller 42 of the disk drive determines whether a channel parameter optimization execution command is received from the host interface circuit 54 (S410).

When the channel parameter optimization execution command is received as a result of the determination in step 410 (S410), an adaptive variable range (min, max) is set for each parameter to be optimized, and the minimum value (min) and the maximum value (max) of the variable range are set. ) Are stored in the second and third registers 320-2 and 320-3, respectively (S420).

Here, the adaptive variable range refers to a parameter variable range that does not include a parameter value for generating divergence during channel optimization for each parameter for determining channel characteristics.

Next, a parameter value for generating optimal channel performance is determined while varying the value of the parameter within the adaptive variable range set in step 420 (S420). That is, the parameters to be optimized are varied within the minimum and maximum values stored in the second and third registers 320-2 and 320-3 and applied to the read / write channel circuit 44, and then the channel performance is evaluated. The parameter value that generates the best channel performance is determined (S430).

The parameter value determined in step 430 (S430) is stored in the maintenance cylinder area of the ROM 50 or the disk 12 as an optimal value to be actually applied (S440).

Accordingly, an optimal parameter value can be found while varying within a variable range adaptively determined within a range in which divergence does not occur for each parameter during channel optimization.

That is, in the present invention, as shown in FIG. 3, the second register 320-2 (R _min ) for setting a variable range of the parameter to be optimized at the time of channel optimization, that is, the minimum value min and the maximum value max, and Using the third register 320-3 (R _max ), it is possible to find an optimal parameter value while preventing divergence.

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 on a transmission medium or 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. That is, it is a matter of course that the present invention can be applied to various disk drives including a hard disk drive.

As described above, according to the present invention, by performing channel optimization within a limited range in which no divergence is generated by using a register for setting a variable range of a parameter during channel optimization, it is possible to prevent divergence from occurring during channel optimization. Can be produced. This produces an effect of reducing the failure of the read / write channel of the disk drive.

Claims (10)

Setting a variable range such that parameter values for generating divergence during channel optimization are not included for each parameter; Determining a parameter value for generating an optimal channel characteristic while changing an initial setting value of a corresponding parameter within the set variable range; And And storing the determined optimal parameter value as a value to be actually applied of the corresponding parameter. The method of claim 1, wherein the variable range is determined as a minimum value and a maximum value, and the minimum value and the maximum value are stored in different registers. 2. The method of claim 1, wherein the parameter comprises parameters that determine a characteristic of a channel of the disk drive. A first register storing an initial setting value for each parameter for determining channel characteristics; A second register for storing a minimum value of a variable range set such that a parameter value for generating divergence during channel optimization for the parameter is not included; A third register for storing a maximum value of the variable range; And Initialize the system by applying the parameter value stored in the first register to the read / write channel circuit, and the value stored in the second register and the value of the parameter applied to the read / write channel circuit in the channel optimization mode. Adaptive channel parameter optimization, characterized in that it includes a parameter optimization control unit for evaluating the channel performance while varying within the range between the values stored in the three registers, to determine the value that generates the optimal channel performance as the optimum value of the parameter Device. 5. The apparatus of claim 4, further comprising a fourth register for storing the optimal value of the parameter. 5. The apparatus of claim 4, wherein the parameter controller controls to read and store information designated to each of the first, second, and third registers from a nonvolatile memory before executing the channel optimization mode. 6. A disk for storing information; A read / write channel circuit for performing data write and read processing for writing data to the disk or restoring data read from the disk; A memory in which variable range information is set such that an initial setting value and a parameter value for generating divergence during channel optimization are not included for each parameter for determining channel characteristics of the read / write channel circuit; And Initialize the system by applying the initial setting value of each parameter stored in the memory as the parameter value of the read / write channel circuit, and within the variable range the values of the parameter applied to the read / write channel circuit in the channel optimization mode And a system controller that evaluates channel performance while varying and determines a value that generates optimal channel performance as an optimal value of a corresponding parameter. The system of claim 7, wherein the system control unit A first register storing an initial setting value for each parameter read from the memory; A second register for storing a minimum value of a variable range set such that a parameter value for generating divergence during channel optimization for the parameter is not included; A third register for storing a maximum value of the variable range; And Initialize the system by applying the parameter value stored in the first register to the read / write channel circuit, and the value stored in the second register and the value of the parameter applied to the read / write channel circuit in the channel optimization mode. And a parameter optimization control unit for evaluating channel performance while varying within a range between the values stored in the third register, and determining a value for generating optimal channel performance as an optimal value of the corresponding parameter. 8. The disk drive of claim 7, further comprising a fourth register for storing an optimal value of the parameter. 8. The disk drive of claim 7, wherein the channel optimization mode is performed in a burn-in process of the disk drive.

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