KR200214053Y1 - Servo sector structure for increasing data area in hdd - Google Patents

Abstract

According to the present invention, in the servo sector structure of a hard disk drive in which servo information is recorded in a headerless servo recording pattern, the sector number area for recording the serial number of the servo sector is removed, and the index for recording the first rotation information of the disk is recorded. And a servo section for recording the index bit information indicating the first sector number of the servo sector group including a plurality of servo sectors in the area, and a data section for recording various information data.

Description

SERVO SECTOR STRUCTURE FOR INCREASING DATA AREA IN HDD}

The present invention relates to a hard disk drive employing a headerless servo writing pattern, and more particularly, to a servo sector structure of a hard disk drive capable of extending a data section by removing a sector number.

A hard disk drive widely used as an auxiliary memory device of a computer system is configured as shown in FIG. 1.

FIG. 1 is a block diagram of a general hard disk drive in which a printed circuit board (PCB) and a head disk assembly (HDA) are combined, and includes two disks 2 and four heads 4 corresponding thereto. The following shows an example of a multi-platter hard disk drive. In a multi-platter hard disk drive, the disks 2 are typically installed in one spindle motor 30 as a stack, and each disk surface corresponds to one head 4. The head 4 is located on the surface of the disc 2 and is mounted on a vertically extending arm 8 of the arm assembly of a rotary voice motor (VCM) 24. The preamplifier 12 preamplifies the signal picked up by one of the heads 4 during data read, and applies the preamplified signal to the read / write channel circuit 14. Encoded write data applied from the write channel circuit 14 is driven to one of the heads 4 to be written onto the disc 2. At this time, the preamplifier 12 selects one of the heads 4 under the control of the disk data controller (DDC) 32 controlled by the microcontroller 18. The read / write channel circuit 14 detects and decodes a data pulse from a read signal applied from the preamplifier 12 to generate read data RDATA, and decodes the write data WDATA applied from the DDC 32 to decode the preamplifier 12. ) Is applied. The read / write channel circuit 14 also demodulates the head position information which is a part of the servo information recorded on the disk 2 to generate a position error signal (PES). The PES generated from the read / write channel circuit 14 is applied to an analog-to-digital converter 16, and the A / D converter 16 sets the PES to a digital step value corresponding to its level. To the microcontroller 18. The DDC 32 is controlled by the microcontroller 18 and writes data received from the host computer onto the disc 2 via the read / write channel circuit 14 and the preamplifier 12 or onto the disc 2. The data is read from and sent to the host computer. The DDC 32 also interfaces the communication between the host computer and the microcontroller 18. The microcontroller 18 controls the DDC 32 in response to read or write commands received from the host computer and controls track searching and track following. At this time, the microcontroller 18 controls the track tracking as described above using the PES value applied from the A / D converter 16. The digital-to-analog converter 20 converts the control values for position control of the heads 4 generated from the microcontroller 18 into analog signals. The VCM driver 22 generates a driving current I (t) for driving the actuator by a signal applied from the D / A converter 20 and applies it to the VCM 24. The VCM 24 moves the heads 4 horizontally on the disc 2 in correspondence with the direction and level of the drive current input from the VCM driver 22. The motor controller 26 controls the spindle motor driver 28 according to a control value for rotation control of the disks 2 generated from the microcontroller 18. The spindle motor driver 28 rotates the disks 2 by driving the spindle motor 30 under the control of the motor controller 26. In the hard disk drive having the above-described configuration, the head 4 must be moved on the target track for data read / write operation. In this case, the microcontroller 18 performs speed control and position control for moving the head 4 onto the target track by using the servo information written by the servo writer.

Hereinafter, a servo pattern recorded on the disc 2 by the servo writer during the manufacturing process will be described with reference to FIG. 2.

FIG. 2 shows the servo sector format of a specific track on the disc 2, wherein each track arranged concentrically on the disc 2 has an alternate servo section and data section as shown in FIG. In this case, the servo section and the data section constitute one servo sector. On the other hand, in the hard disk drive employing the headerless servo method, since there is no data ID in the data section, a more enhanced servo check is performed to guarantee this. To this end, in the hard disk drive employing the headerless servo method, index, head, sector, and cylinder information are recorded in the servo section as shown in FIG. In other words, the servo section of the hard disk drive employing the headerless servo method is a preamble section for synchronizing with the system clock and a servo address mark (SAM), which records reference patterns for generating various servo timings. Section, an index (Index: IDX) section for providing disk rotation information, a sector number section in which the number of the servo sector is recorded, a head number section in which the head number is recorded, and a gray code in which track information is recorded. (Gray Code) section, servo burst section and postamble section for on-track control of the head.

The index information IDX is usually composed of 1 bit, and the sector number (7 bits) and the head number (2 to 3 bits) can vary depending on the drive capacity. The purpose of adopting the servo recording pattern as described above was to increase the data capacity by removing the data ID from the data section. However, the servo recording pattern was relatively increased in order to enhance the servo information. In addition, in the hard disk drive employing the conventional headerless servo recording pattern, there is a problem in that the accuracy of the servo information cannot be determined if the servo information is incorrectly written on the servo section.

Accordingly, an object of the present invention is to provide a servo sector structure of a hard disk drive that can extend a data section by removing a sector number in the servo section in a hard disk drive employing a headerless servo recording pattern.

The present invention for achieving the above object in the servo sector structure of the hard disk drive in which the servo information is recorded in the headerless servo recording pattern, the sector number area for recording the serial number of the servo sector is removed, And a servo section for recording the index bit information indicating the first sector number of the servo sector group composed of a plurality of servo sectors in the index area in which one rotation information is recorded, and a data section for recording various information data. It is done.

1 is a block diagram of a typical hard disk drive,

2 is a sector format diagram of a predetermined track of a disk partitioned into a plurality of servo sectors;

3 is a layout of the disc 2 layout according to an embodiment of the present invention,

4 is a detailed format diagram of a servo section according to an embodiment of the present invention;

5 is a control flowchart according to an embodiment of the present invention.

Hereinafter, an operation according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, many specific details, such as the number of bits of each servo information and the specific processing flow, are shown to provide a more general understanding of the present invention. It will be apparent to those skilled 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 obscure the subject matter of the present invention will be omitted.

3 shows a layout diagram of a disc 2 according to an embodiment of the present invention, wherein the disc 2 is largely divided into eight servo sector groups. If the number of servo sectors present in each track arranged concentrically on the disc 2 is 72, the group of servo sectors includes nine servo sectors. In this case, in order to help the present invention, the first group of servo sectors will be referred to as a servo sector group, and the servo sectors present in each servo sector group will be referred to as weak sectors. In order to distinguish the servo sector groups, the main index information is recorded in the servo section of the first sector of the predetermined servo sector group, and the sub index information is recorded in the servo section of the first sector of the remaining servo sector group. Sector groups are distinguished.

Hereinafter, the configuration of servo information according to an embodiment of the present invention will be described with reference to FIG. 4.

4 is a detailed format diagram of a servo section according to an embodiment of the present invention, and has a servo recording pattern in which a sector number is removed in a conventional servo section. Referring to FIG. 4, the servo recording pattern according to the embodiment of the present invention is compared with the conventional servo recording pattern as follows. First, the servo recording pattern according to an embodiment of the present invention has an index section composed of 3 bits. In this case, the 3 bits indicate that the segment is divided into eight servosector groups as shown in FIG. 3, and may vary according to the number of partitions of the servosector group. That is, when the value of the bit information recorded in the index section is changed from '000' to '001', the microcontroller 18 may recognize that the first servo sector group is changed from the second servo sector group. On the other hand, in the servo recording pattern according to the embodiment of the present invention, by removing the conventional 7-bit sector number, the 5-bit servo section can be reduced despite the 2-bit extension of the index section.

Hereinafter, a sector number counting process of a hard disk drive using a disk having the above-described servo recording pattern as a recording medium will be described with reference to FIG. 5.

FIG. 5 is a flowchart illustrating a control flow of the microcontroller 18 according to an embodiment of the present invention. Hereinafter, a sector number counting process will be described with reference to FIGS. 1 and 5.

First, when the servo interrupt occurs in step 40, the microcontroller 18 starts the timer in step 42 and proceeds to step 44. At this time, the sector number is updated by the counting operation of the timer. In operation 44, the microcontroller 18 checks whether an index bit is detected. If the test bit is detected, the microcontroller 18 proceeds to step 46 to start the index timer. Thereafter, in step 48, the microcontroller 18 saves the sector number according to the counting value of the index timer based on the sector number corresponding to the detected index bit information. That is, if the detected index bit is '000', the sector number may be calculated based on the counting value of the index timer based on the first sector (first sector of 72 sectors) of the first servo sector group. If the index bit detected by the same method is '001', the sector number may be calculated based on the counting value of the index timer based on the first sector (the ninth sector of the 72 sectors) of the second servo sector group. If the index bit cannot be detected due to an external environment or an error in the servo information recording in step 44, the microcontroller 18 proceeds to step 50 to detect the first sector of the servo sector group corresponding to the detection of the next index bit. It is checked whether the number and the sector number updated by the counting operation of the timer started in step 42 are the same. If the value of the sector number is the same, the microcontroller 18 proceeds to step 48 to save the sector number. If the value of the sector number is not the same, the microcontroller 18 proceeds to step 52 after protecting the read / write operation. do. In step 52, the microcontroller 18 updates the count value of the index timer started by the index bit detected in step 50, the first sector number of the servo sector group corresponding to the index bit detection, and the timer started when the interrupt occurs. Check that all sector numbers that are given are the same. If the three sector number values are the same, the microcontroller 18 proceeds to step 48 to save and use the counted sector number. On the other hand, if the three sector number values are not the same, the microcontroller 18 sets the retry bit and proceeds to step 54 and waits until the next index bit is detected. After that, if an index bit detection error occurs, the error number is reported and the sector number counting process according to the embodiment of the present invention is terminated.

As described above, the present invention can extend the data section by removing the sector number existing in the servo section, and can secure the reliability of the drive by preventing the error of the servo information recorded incorrectly on the servo section. .

Claims (2)

In the servo sector structure of a hard disk drive in which servo information is recorded in a headerless servo recording pattern, The sector number area for recording the serial number of the servo sector is removed, and the index bit information indicating the first sector number of the servo sector group composed of a plurality of servo sectors is stored in the index area in which the first rotation information of the disk is recorded. Recorded servo section, A servo sector structure of a hard disk drive for expanding a data section, characterized by comprising a data section in which various information data is recorded. The method of claim 1, wherein the index bit information, The servo sector structure of a hard disk drive for data interval extension, characterized in that the binary information is recorded in two or more bits according to the number of partitioned servo sector groups.