KR0183152B1 - A magnetic recording apparatus - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

A method of setting various control variables in a magnetic disk recording apparatus.

2. Technical problem to be solved by the invention

In the case of assembling the head disk assemblies with different kinds or different characteristics with one PCBA, various control variables can be set adaptively without changing the hardware.

3. Summary of Solution to Invention

A ROM having control variable values corresponding to different types / characteristics of the head disk assemblies, and a channel for distinguishing the type / characteristic of the head disk assembly when recording servo information on the disk of the head disk assemblies. The ID is included in the servo information corresponding to each head disk assembly and recorded, and the channel ID is checked from the servo information read out from the disk, and the corresponding control variable values are loaded from the ROM, and the corresponding magnetic disk recording apparatus is loaded. Set to control variable values.

4. Important uses of the invention

A head disk assembly having different types / characteristics is used to set various control variables in a magnetic disk recording apparatus which is assembled with one PCBA.

Description

Control Variable Setting Method of Magnetic Disk Recording Device

1 is a block diagram of a HDD to which the present invention is applied.

2 is a conventional servo information recording format diagram.

3 is a servo information recording format diagram according to the present invention.

4 is a flow chart according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk recording apparatus, and more particularly to a method of setting various control parameters for read / writ channel or servo control.

In general, magnetic disk recording devices such as hard disk drives (hereinafter referred to as HDDs) and floppy disk drives (hereinafter referred to as FDDs) are widely used as auxiliary storage devices of computer systems. Among them, HDDs not only stably store large amounts of data but also have advantages of high-speed access.

In order to increase the storage capacity of the disk in the HDD as described above, the recording density on the disk is gradually increasing, and accordingly, the head (or data transducer) is also being highly precise. As the recording density increases and the head becomes more accurate, various control variables such as read / write channel variables and servo control codes are emerging as more important and sensitive variables in the performance of the HDD.

The read / write channel variable is a variable for controlling the read / write circuit and the read / write channel circuit of the HDD, for example, blocking of a write current applied to the head or a filter provided in the read / write channel circuit. Cut off frequency, filter boost, threshold for qualification, and the like. The read / write circuit pre-amplifies the signal picked up by the head at the time of reading to generate an analog read signal. During recording, the recording data is written onto the disc by applying a recording current according to the encoded recording data to the head. Be sure to The read / write channel circuit detects and decodes a data pulse from a read signal applied from the read / write circuit, encodes data to be written, and applies it to the read / write circuit.

In addition, the servo control code may be, for example, a bias value as a control code for a servo mechanism. If these control variables are not set properly, a data error will occur. For example, if the recording current value is inappropriate, the signal amplitude may be reduced or distorted due to inter-bit interference. If the filter boost value is inappropriate, the signal shift may cause a signal shift, causing a data error. .

In general, techniques for optimizing various control variables as described above have been proposed to minimize such errors. As such techniques, a patent application number 95-12313 filed by the applicant of the Korean Patent Office on May 17, 1995, a method of setting the read channel factor value of a hard disk drive, or a patent application filed on November 22, 1995 No. 95-42993, a read channel optimization method for a hard disk drive, a patent application No. 95-53518 filed on December 21, 1995, a write current control circuit of a magnetic disk recording apparatus, and an optimization method thereof.

The optimized control variables are stored as a microcode in a ROM (Read Only Memory) storing a program of a microcontroller, which is a main controller of the HDD, to be used in actual HDD operation.

The above-described techniques are suitable for assembling HDAs (Head Disk Assemblies) that do not have the same type or characteristic differences when assembling HDDs in one printed circuit board assembly (PCBA). In general, a PCBA in an HDD means a part including all the circuit elements assembled on the PCBA including the read / write circuit and the read / write channel circuit. HDA, on the other hand, means all parts except the PCBA, ie the head and the disk.

However, in fact, HDD manufacturers manufacture several models of HDD. Looking at the typical HDD production process, first assembled HDA and PCBA separately. At this time, the HDA goes through the servo write process to record the servo information on the disk after the assembly is completed, and then the PCA performs the function test after the assembly is completed. In addition, the ROM stores the program and microcodes according to various setting values including the control variable values as described above and assembles them in the PCBA. The HDA and PCBA thus prepared are assembled together to complete the HDD.

At this time, if the type or characteristics of the head or disk constituting the HDA and the servo mechanism according to them are different, the configuration of the PCBA or the microcode of the ROM should be changed accordingly in each case. For example, assuming that the head is assembled with one PCBA using two heads, one of a thin film head and a double Mig head, to produce an HDD, the characteristics of the head are completely different. As a result, data errors occur as a result of using the same device ROM in PCBA. Also, even when the same head is used, if the number of heads varies according to the recording capacity, the servo control code must be different even though the read / write channel parameters are the same, so the ROM must be used differently.

Therefore, if the type of HDA is completely different or the characteristic difference is large, the PCBA must be changed and assembled for each HDA. In this PCBA, the circuits except some circuits and ROMs are the same, but the circuits and ROMs are different, so HDD manufacturers have to take the production process of PCBA differently in each case, as well as the microcode of PCBA and ROM. You have to manage the revision differently.

As described above, in the case of producing HDDs by assembling HDAs having a completely different type or a large characteristic difference with one PCBA, not only the hardware has to be changed, but also the trouble of managing the PCBA and the microcode revision separately. There was a difficulty.

Accordingly, an object of the present invention is to provide a control variable setting method capable of adaptively setting control variables without changing hardware when HDAs having different kinds or large characteristic differences are assembled with one PCBA.

The method of the present invention for achieving the above object has a ROM having control variable values correspondingly set for each different type / characteristics of the HDAs, and when the servo information is recorded on the discs of the HDAs, The channel ID to distinguish the characteristics is included in the servo information corresponding to each HDA, recorded, and the channel ID is checked from the servo information read out from the disk, and the corresponding control variable values are loaded from the ROM. And setting the control variable values of the disk recording apparatus. As described above, the channel ID is used to distinguish the types / characteristics of the head, disk, and servo mechanism used in the HDA to be assembled with one PCBA, and is set to different values according to the types / characteristics of the HDA.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention, such as specific processing flows, servo information recording formats, and the like. It will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. And a detailed description of known functions and configurations that may unnecessarily flow the gist of the present invention will be omitted.

1 is a block diagram of an HDD to which the present invention is applied, and shows an example in which two disks are installed as stacks on one spindle and four heads corresponding to one side of each disk. Referring to FIG. 1, the configuration and operation of a HDD useful for understanding the present invention will be described as follows.

The disk 10 is rotated by the spindle motor 34. The heads 12 are each located on a corresponding one of the disks 10 and are combined with an annular voice coil actuator 30 and an E-block assembly 14. Respectively corresponding to a support arm extended from the disk 10 toward the disk 10.

The read / write circuit 16 connected to the head 12 pre-amplifies the signal picked up by one of the heads 12 when reading, and applies an analog read signal to the read / write channel circuit 18. At the time of recording, the recording data is recorded on the disc by applying a recording current according to the encoded recording data applied from the read / write channel circuit 18 to one of the heads 12 selected from the heads.

The read / write channel circuit 18 detects and decodes a data pulse from a read signal applied from the read / write circuit 16 and applies it to a disk data controller (DDC) 20, and applies it from the DDC 20. The recorded data is encoded and applied to the read / write circuit 16.

The DDC 20 is controlled by the microcontroller 24 and read / write channel circuit 18 and read / write circuit 16 to read data received from a host computer such as a personal computer (PC). The data is recorded on the disk 10 or the data is read from the disk 10 and transmitted to the host computer. The DDC 20 also interfaces the communication between the host computer and the microcontroller 24. A random access memory (RAM) 22 temporarily stores data transmitted between the host computer, the microcontroller 24 and the read / write channel circuit 18.

The micro controller 24 controls the DDC 20 in response to a read or write command received from a host computer and controls track search and track following. The ROM 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 by the signal for controlling the position of the head 12 generated from the microcontroller 24 and applies it to the actuator 30. The actuator 30 moves the head 12 on the disk 10 corresponding to the direction and level of the drive current applied from the servo driver 28. The spindle motor driver 32 drives the spindle motor 34 to rotate the disk 10 according to a control value for rotation control of the disk 10 generated from the microcontroller 24. The disk signal controller 36 decodes servo information from the read data output from the read / write channel circuit 18 to the microcontroller 24 and applies various control signals necessary for read / write from the DDC 20. The signal is generated and controlled by the microcontroller 24 and applied to the read / write circuit 16, the read / write channel circuit 18, the DDC 20, and the like. The disk signal controller 36 typically uses an ASIC (Application Specific Integrated Circuit) designed for each HDD.

The present invention applied to the HDD as described above first distinguishes the type / characteristics of the head and disk used in the HDA when the servo information is recorded by the servo writer on the disk in the state where the assembly of the HDA is completed. The channel ID to be included is recorded in the servo information differently according to the head and the disk, which will be described in detail below.

First, in the HDD, to selectively position the head on a particular track, it is necessary to know the current head position relative to the tracks. As such, servo information informing the head position relative to the tracks is provided by using a particular servo pattern that is read on the disc by the head. This servo pattern is permanently recorded on the disk in advance by the servo writer when assembling the HDD. This servo pattern is used as track position information by being detected by the head when accessing data on the disk. One example of a method for providing servo information is an embedded servo method. In the embedded servo system, servo information is arranged between data areas on a disk.

The normal recording format of such servo information is shown in FIG. 2 as an example of the embedded servo method, and is not an accurate scale. In FIG. 2, servo information consisting of a servo address mark (hereinafter referred to as SAM), an index, a track address, a burst, and the like is recorded in a servo feed on a disc. The servo address mark is a signal of a specific pattern indicating the start of the servo feed. The index is information for defining each track. For example, the track is recorded as logic 1 in the first servo feed of each track and logic 0 is recorded in all the remaining servo feeds. The track address is track position information and indicates position information of the track and the servo sector. Burst is information for controlling the position of the head, which is used to on-track the head when tracking a track.

In the conventional servo information recording format as shown in FIG. 2, the channel ID according to the present invention is included to configure the servo information recording format as shown in FIG. In the embodiment of the present invention, the channel ID is located between the index and the track address as shown in FIG. In this case, the channel ID is positioned after the index to facilitate detection, but may be different. As described above, the channel ID is used to distinguish the type / characteristics of the disk 10, the head 12, the actuator 30, the spindle motor 34, etc. used in the HDA to be assembled with one PCBA. Set different values according to the type / characteristic of the HDA. An example in which eight cases are designated as such a channel ID as three bits is shown in Table 1 below.

The above table (1) illustrates the case where the type of disk and servo mechanism are the same, but the number and type of heads vary depending on the number of disks.

As described above, the channel ID is included in the servo information and recorded, and corresponding to the respective control variable values optimized by the sample HDD in advance in correspondence with the types / characteristics of the HDA in the ROM 26 in FIG. Save the microcodes. At this time, each microcode is distinguished according to the channel ID.

In this state, when the function test for the HDA, after the assembly of the HDA and PCBA to complete the HDD to perform the function test, when the actual HDD is used, the microcontroller 24 according to the flow chart of FIG. Perform the action. However, since only HDA is present in the function test for the HDA, this operation is performed by the microcontroller of the function test apparatus instead of the microcontroller 24. The program according to the flowchart of FIG. 4 is also programmed in the ROM 26.

First, the microcontroller 24 initializes and diagnoses each part of the HDD in operation 400, and then drives the spindle motor 34 through the spindle motor driver 32 in operation 402. When the spindle motor 34 rotates at the normal speed, the servo is controlled through the servo driver 28 in step 404 and read from the disk 10. From this, the SAM notifying the start of the servo information as shown in FIG. Examine whether or not At this time, the SAM is typically detected by the disk signal controller 36, which detects the SAM by decoding the read data applied from the read / write channel circuit 18.

If the SAM is not detected in step 404, an error occurs and an error report is made. Here, of course, when the initialization and diagnosis or the spindle motor is not normal, the error report is omitted, but is omitted.

On the other hand, if the SAM is normally detected in step 404, the channel ID as described above is checked from the servo information read from the disk 10 in step 406. At this time, the disk signal controller 36 inputs and decodes the data read from the disk 10 from the read / write channel circuit 18 to provide the micro controller 24 with the channel ID included in the servo information as shown in FIG. do.

When the channel ID is confirmed as described above, the microcontroller 24 corresponds to the control variable value, that is, the channel ID, among the various control variable values stored in the ROM 26 in step 408. The read / write channel variable values and the servo control code are loaded from the ROM 26 to set the control variable values of the corresponding HDA or HDD. The read / write channel variable values loaded as described above are set to various variable values of the read / write circuit 16 and the read / write channel circuit 18 through the disk signal control beam 36.

Next, the microcontroller 24 is prepared after performing recalibration of the servo mechanism in step 410 according to the servo control code set as described above. Accordingly, the control variable values set as described above are used as default values during the normal HDA function test or HDD function test or when the actual HDD is used.

Therefore, even if HDAs are completely different or have different characteristics, HDAs are assembled with a single PCBA, and even if HDDs are produced, there is no need to change the PCBA circuitry or hardware such as ROM.

As described above, the present invention has the advantage that the control variable values can be adaptively set without changing the hardware even when HDAs of different kinds or large characteristic differences are assembled with one PCBA.

Meanwhile, 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. In particular, although the example of the HDD has been described, all of them can be applied to the magnetic disk recording apparatus such as the FDD as well as the HDD without any special modification. Therefore, the scope of the invention should not be defined by the described embodiments, but should be defined by the equivalents of the claims and the claims.

Claims (3)

A control variable setting method of a magnetic disk recording apparatus having a ROM having control variable values set corresponding to different types / characteristics of head disk assemblies, the method comprising: when recording servo information on a disk of the head disk assemblies; A channel ID for classifying the type / characteristic of the head disk assembly is included in the servo information corresponding to each head disk assembly and recorded, and the channel ID is checked from the servo information read from the disk. And setting control variable values corresponding to the control variable values of the magnetic disk recording apparatus by loading corresponding control variable values from the ROM. The method of claim 1, wherein the set control variable values are used as default values in the operation of the magnetic disk recording apparatus. The method of claim 2, wherein the control variable values comprise read / write channel variable values and servo control codes of the magnetic disk recording apparatus.