JP2010055718A - Hard disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard disk device suitable for recording of a video stream by fixing recording speed of data. <P>SOLUTION: The hard disk device includes a magnetic disk 6, two disk heads 8U, 8L, and a controller 3 controlling read/write of data. Two disk heads 8U, 8L are provided for reading and writing of a first face and a second face of the magnetic disk 6, respectively. The controller 3 controls the disk head 8U of one side so as to perform recording from the outer periphery of the first face to the inner periphery, and controls simultaneously the disk head 8L of the other side so as to perform recording from the inner periphery of the second face to the outer periphery, and allocates the number of sectors of the first face and the second face so that the total number of sectors recorded by both the disk heads 8U, 8L is fixed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a hard disk device, and more particularly, to a hard disk device that maintains a constant recording / reproduction rate in a computer or an image recording device.

  Currently used hard disk drives (HDDs) record data from the outer periphery of the disk toward the inner periphery. Usually, a hard disk device includes a plurality of magnetic disks, an HDD controller that reads and writes data, and a temporary storage memory (cache memory) that ensures stable read / write control between the HDD controller and the magnetic disk. ing. Data is recorded in a recording unit (usually 512 bytes) called a sector. Dividing the disk surface into tens of minutes in the radial direction (zone division), and recording within a single divided zone effectively uses the area so that the surface recording density of the disk is almost constant By doing so, the capacity is increased (zone recording method).

  However, since the HDD operates at a constant disk rotation speed, the transfer rate may change nearly twice as much between the innermost and outermost disks of the disk due to the difference in the number of sectors in the outer and inner peripheral parts.

  Therefore, a recording method is disclosed in which a recording rate is made constant for a plurality of discs by pairing a disk surface recorded from the outer periphery and a disk surface recorded from the inner periphery (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 5-282842

  Since the video stream has a constant bit rate, when the video stream is recorded by the HDD, the maximum video bit rate that can be recorded is limited by the recording rate on the inner circumference side with the slowest transfer rate. Therefore, in order to record a higher-speed video stream such as a broadcast video stream (uncompressed high-definition 1.5 Gbps), data is simultaneously recorded on a plurality of hard disks (two or more) (striping). A recording method or the like is used.

  However, in the simple striping recording method, there is still a difference between the recording rates of the outer periphery and the inner periphery of the disc, and the maximum recordable rate is still limited to the minimum transfer rate on the inner periphery side. Therefore, for recording a video stream, it is required to minimize the difference in transfer rate between the outer peripheral portion and the inner peripheral portion.

  An object of the present invention is to provide a hard disk device suitable for recording a video stream, in which the data recording speed is almost constant.

  In order to solve the above problems, the total number of sectors from the inner to the outer periphery of the disk is determined by recording both sides of the disk as one unit and recording one recording surface from the outer periphery and the other recording surface from the inner periphery. The hard disk suitable for recording a video stream with a data recording speed close to a constant is realized.

  Also, by preparing two pairs of double-sided disk heads, even if one disk disk head of one pair breaks, for example, the other disk head can form a pair of disk heads and record / reproduce. It can be so.

  A hard disk device according to the present invention is a hard disk device including a magnetic disk, two disk heads, and a controller for controlling reading and writing of data, each of the two disk heads being a first surface of the magnetic disk. The controller controls one disk head to record from the outer periphery to the inner periphery of the first surface, and controls the other disk head to the second surface. Recording control means for simultaneously controlling recording from the inner periphery to the outer periphery of the surface, and the sectors on the first surface and the second surface so that the total number of sectors recorded by both disk heads is constant. Sector allocation means for allocating numbers.

  Further, in the hard disk device according to the present invention, the hard disk device further includes a nonvolatile memory, and the controller includes a means for detecting a defective sector of the recording disk, and an alternative sector area corresponding to the defective sector as the nonvolatile sector. Alternative sector holding means for securing in the memory, wherein the recording control means includes the first surface including the alternative sector area so that the total number of sectors recorded by both disk heads is constant. Control is performed so as to allocate the number of sectors on the second side.

  Further, in the hard disk device according to the present invention, each of the two disk heads is composed of two disk heads for reading and writing on both sides of the magnetic disk, and the controller is one of the disk heads for reading and writing on both sides. The apparatus further comprises a head selecting means for selecting one of the recording heads, and the recording control means simultaneously controls the recording of the two disk heads selected by the head selecting means.

  Since the data recording speed can be made constant, a hard disk suitable for recording a high-speed video stream having a constant bit rate can be provided.

  A hard disk device according to an embodiment of the present invention will be described.

[Device configuration]
FIG. 1 is a schematic diagram of a hard disk device according to an embodiment of the present invention. The hard disk device 1 includes a data stream interface (I / F) 2, an HDD controller 3 that controls reading / writing of data, a first temporary storage memory (cache memory) 4 for the first disk surface, and a second disk memory device. The second temporary storage memory (cache memory) 5 for the surface and the hybrid recording / reproducing unit 9 are included to constitute a hybrid recording / reproducing hard disk device. The hybrid recording / reproducing unit 9 includes a nonvolatile memory (flash memory) 7 for storing defective sectors, one or more magnetic disks 6 (three magnetic disks 6-1, 6-2, 6-3 in the figure), One or more disk heads for the first surface of the magnetic disk (three 8-1U, 8-2U, 8-3U in the figure) and one or more disk heads for the second surface of the magnetic disk ( In the figure, three disk heads 8-1L, 8-2L, and 8-3L) are provided.

  The data stream interface (I / F) 2 is, for example, a SAS interface or known as a SATA interface, and receives external data (for example, a packet of a data stream) in a first temporary storage memory (cache memory) 4 or a second temporary memory. Recording / reproducing of the hybrid recording / reproducing unit 9 is made possible via a storage memory (cache memory) 5.

  The first temporary storage memory (cache memory) 4 is usually composed of a volatile memory, and is stable to the first disk surface (the disk heads 8-1U, 8-2U, 8-3U side) under the control of the HDD controller 3. This is a temporary storage memory for ensuring read / write control.

  The second temporary storage memory (cache memory) 5 is usually composed of a volatile memory, and is stable with respect to the second disk surface (disk heads 8-1L, 8-2L, 8-3L side) under the control of the HDD controller 3. This is a temporary storage memory for ensuring read / write control.

  Three disk heads 8-1U, 8-2U, 8-3U (hereinafter also collectively referred to as a read / write disk head 8U on the first surface side), and three disk heads 8-1L, 8-2L, 8- 3L (hereinafter also collectively referred to as the second surface side read / write disk head 8L) includes a first surface (upper side) and a second surface for the first to third disks 6-1, 6-2 and 6-3, respectively. It means the upper side and the lower side of the surface (lower) disk head.

  The read / write disk head 8U on the first surface side performs recording / reproduction from the outer periphery of the magnetic disk, and the read / write disk head 8L on the second surface side performs recording / reproduction from the inner periphery of the magnetic disk. The reading and writing of the surface is controlled by the HDD controller 3 so as to be performed simultaneously.

  That is, one magnetic disk is provided with two disk heads for both disk surfaces. Under the control of the HDD controller 3, of the disk heads for both disk surfaces, the upper and lower disk heads are mutually used. It is selected so that simultaneous recording / reproduction is possible. This selection can be set for each magnetic disk. Alternatively, as another aspect, it is possible to provide two disk heads for both sides of the magnetic disk, as shown in FIG. Will be described later.

  The non-volatile memory (flash memory) 7 is a flash memory for securing a storage area for functioning as a substitute sector for a defective sector under the control of the HDD controller 3. Details of the nonvolatile memory (flash memory) 7 will be described later.

  The HDD controller 3 can control the data stream interface (I / F) 2, the first temporary storage memory (cache memory) 4, the second temporary storage memory (cache memory) 5, and the hybrid recording / reproducing unit 9. When two disk heads are provided for reading and writing on the first surface and the second surface of each magnetic disk, respectively, one disk head is moved from the outer periphery to the inner periphery of the first surface of each magnetic disk. While controlling to record, the other disk head is simultaneously controlled to record from the inner surface to the outer surface of the second surface of each magnetic disk, and the total number of sectors recorded by both disk heads is constant. As described above, the number of sectors on the first surface and the second surface of each magnetic disk is assigned.

  Further, the HDD controller 3 has a function of detecting a defective sector of each recording disk and securing an alternative sector area corresponding to the defective sector in the nonvolatile memory 7, and has a total number of sectors recorded by two disk heads. Is controlled so that the number of sectors on the first surface and the second surface of each magnetic disk including the alternative sector area in the nonvolatile memory 7 is allocated.

  Further, for example, when each of the two disk heads is configured by a double-sided read / write disk head of each magnetic disk, the HDD controller 3 arbitrarily selects one of the double-sided read / write disk heads. It has a function of selecting and simultaneously controlling recording of the two selected disk heads.

  More specific description will be given below. The HDD controller 3 performs selection of the read / write disk head 8U on the first surface side and the read / write disk head 8L on the second surface side (to be described later with reference to FIG. 2), writing control thereof, and defects in each disk. Storage control of the non-volatile memory (flash memory) 7 is performed for the alternative sector of the sector via both (or either) the first temporary storage memory (cache memory) 4 and the second temporary storage memory (cache memory) 5. Do. Also, the HDD controller 3 controls the number of sectors so that the number of sectors added to the inner and outer zones of the pair is constant, with the disk rotation speed being constant.

  Referring to FIG. 2, for example, a case where two disk heads capable of reading and writing on both sides of the magnetic disk 6-1 are illustrated.

  In FIG. 2A, the disk heads 9-1U (upper first surface), 9-1L (lower second surface) and the disk head 10-1U (upper side) with respect to the magnetic disk 6-1. , And the disk head 9-1U and the disk head 10-1L are active (used for reading and writing) with respect to the magnetic disk 6-1. In this example, the HDD controller 3 selects the disk head 9-1L and the disk head 10-1U to be disabled (not used for reading and writing).

  On the other hand, in FIG. 2B, the disk head 9-1L and the disk head 10-1U are activated (used for reading and writing) with respect to the magnetic disk 6-1 (solid line), and the disk head 9-1U and the disk head 10 are activated. In this example, -1L is selected by the HDD controller 3 so as to be disabled (not used for reading and writing).

  As described above, the HDD controller 3 controls to hold the first surface for recording / reproducing from the outer periphery and the second surface for recording / reproducing from the inner periphery with respect to one disk. That is, the HDD controller 3 performs control so as to hold simultaneous recording / reproduction of the outer circumference and the inner circumference for one disk even if one of the disk heads capable of reading and writing on both sides fails.

  Referring to FIG. 3, for example, an example of the sector arrangement of tracks in each zone on the erosion disk 6-1 is shown (see FIG. 3A). The track is composed of a plurality of sectors (0 to Nz (Nz is a natural number of 1 or more including 0)), and the first surface on the upper side of the magnetic disk 6-1 is sequentially recorded from the outermost track to the inner track. It is assumed that the lower second surface of the magnetic disk 6-1 is sequentially recorded from the innermost track to the outer periphery (see FIG. 3B). At this time, the HDD controller 3 controls the number of sectors so that the rotational speed of the disk is constant and the recording density is constant by adding the inner peripheral portion and the outer peripheral portion (see FIG. 3C). Specifically, in order to efficiently secure the recording capacity using the entire disk surface, a large number of sectors are arranged in the outer peripheral portion and are reduced in the inner peripheral portion.

  As described above, the HDD controller 3 uses the disk heads 8U and 8L in pairs in order to reduce the difference in the number of sectors between the inner circumference and the outer circumference for each recording disk, one from the outer circumference and the other from the inner circumference. Recording is performed (see FIG. 1). By considering the two recording surfaces of the magnetic disk as one logical recording surface, the number of sectors can be made nearly constant over the entire circumference of the disk.

  A recording example in which the number of sectors is constant over the entire circumference will be described with reference to FIG. For example, based on the configuration example of FIG. 1, the outermost periphery of the first surface of the magnetic disk 6-1 is zone 0, and the innermost periphery is zone Nz. On the other hand, on the second surface of the magnetic disk 6-1, the zone arrangement is reversed. The total number of zones in the pair disk is Nz + 1.

  In the existing HDD, the number of tracks included in each zone is not always constant. On the other hand, in the hard disk device of this embodiment, the number of sectors for reading and writing by a pair of disk heads is constant, so that the number of tracks in each zone is constant m tracks. This is to keep the total number of tracks read / written by the pair of disk heads constant. Further, the difference in the number of sectors between adjacent zones is set to a constant k so that the difference in the number of sectors in adjacent zones is constant. These sectors can be selected by the HDD controller 3.

Here, assuming that the number of sectors in the innermost zone is L, the total number of sectors including the innermost zone and the outermost zone of the pair disk is 2L + k * Nz. Further, when the total number of sectors in an arbitrary zone position is obtained, the number of sectors of the i-th zone number of the paired disk is L + k * (Nz−i) sectors on the first side and L + k * i sectors on the second side. So in Soichital,
[L + k * (Nz-i)] + [L + k * i] = 2L + k * Nz
And is constant across all zones.

  Next, with reference to FIG. 4, recording of alternative sectors in the nonvolatile memory 7 will be described. A defective sector always exists on the magnetic disk due to a defect or the like (see FIG. 4A). In the conventional HDD, the defective sector is secured in an alternative sector area separately secured on the magnetic disk. Further, in the conventional HDD, in normal recording, a defective sector is detected and not used at the time of initialization. On the other hand, in the hard disk device 1 of this embodiment, in order to make the recording speed of data close to a constant value and suitable for recording a video stream, if the conventional technique is used as it is, the number of sectors in the track in which a defective sector has occurred. As a result, the recording rate cannot be stabilized. In particular, when an alternative sector for a bad sector is secured on the magnetic disk, a seek is generated and the recording rate is significantly reduced.

  Therefore, the hard disk device 1 of this embodiment has a non-volatile memory (flash memory) 7 (see FIG. 4B), is secured as a substitute sector area, and substitute recording of defective sectors is performed on the flash memory. As a result, it is possible to eliminate the performance reduction due to the replacement sector seeking and the replacement. As an alternative sector area, typically, several percent of the total disk capacity in the hard disk device 1 is secured.

  Next, a more detailed operation of the hard disk device 1 of the present embodiment will be described with reference to FIG. 1 and FIG.

[Device operation]
FIG. 4 shows an example of address map recording that takes into account the area of the alternative sector of the nonvolatile memory (flash memory) 7 in the hard disk device 1 according to one embodiment of the present invention. For example, logical addresses are mapped from the first track of zone 0 as shown in FIG. 4 on both surfaces (hereinafter referred to as pair disks) of the magnetic disk 6-1 (see FIG. 4A).

  The HDD controller 3 calculates each data amount on the first surface and the second surface from the zone currently being recorded for recording on the pair disk, and each first temporary storage memory (cache memory) 4 stores the amount of data. L + k * i data (sectors) are allocated to L + k * (Nz−i) data (sectors) and the second temporary storage memory (cache memory) 5.

  The HDD controller 3 performs recording via the first temporary storage memory (cache memory) 4 and the second temporary storage memory (cache memory) 5 in order to efficiently write data to the magnetic disk 6-1, and to detect defective sectors. Corresponding data is stored in the remapped nonvolatile memory (flash memory) 7 (see FIG. 4B).

  This eliminates the need for a seek operation, enables sequential read / write (R / W), and provides a hard disk device suitable for recording a video stream with a data recording speed close to a constant value.

  As described above, the disk heads 8U and 8L may be configured by two pairs of disk heads only on one side, or may be configured as a pair of disk heads corresponding to both sides. When the double-sided disk heads are configured as a pair, the HDD controller 3 changes the pair of disk head disks so that if one of the disk heads breaks, the other disk head can perform recording and playback. To ensure a record rate over the entire circumference.

  Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many variations and substitutions can be made within the spirit and scope of the invention. For example, in the above-described embodiment, the temporary storage memories 4 and 5 have been described as volatile memories. However, together with the nonvolatile memory (flash memory) 7, these memories can be configured as one nonvolatile solid-state memory. . Accordingly, the invention should not be construed as limited by the embodiments described above, but only by the claims.

  According to the present invention, it is possible to create a recording apparatus at a recording rate higher than that of the conventional recording apparatus with an apparently constant transfer rate of the disk, which is useful for any application using an HDD.

1 is a schematic diagram of a hard disk device according to an embodiment of the present invention. It is a figure which shows the example which provided two disk heads which can be read / written on both sides with respect to the magnetic disk in the hard disk apparatus of one Example by this invention. It is a figure which shows the example of the sector arrangement | positioning of the track | truck in each zone on the erosion disk in the hard-disk apparatus of one Example by this invention. It is a figure which shows the example of recording of the alternative sector of the non-volatile memory in the hard-disk apparatus of one Example by this invention.

Explanation of symbols

1 Hard disk device 2 Data stream interface (I / F)
3 HDD controller 4 First temporary storage memory (cache memory)
5 Second temporary storage memory (cache memory) for the second disk surface
9 Hybrid recording / reproducing unit 7 Non-volatile memory for storing bad sectors (flash memory)
6,6-1,6-2,6-3 Magnetic disk 8U, 8-1U, 8-2U, 8-3U Disk head 8L, 8-1L, 8-2L, 8-3L Disk head

Claims (3)

A hard disk device comprising a magnetic disk, two disk heads, and a controller for controlling reading and writing of data,
The two disk heads are provided for reading and writing on the first surface and the second surface of the magnetic disk, respectively.
The controller is
One disk head is controlled to record from the outer periphery of the first surface toward the inner periphery, and the other disk head is simultaneously controlled to record from the inner periphery to the outer periphery of the second surface. Recording control means for
Sector allocating means for allocating the number of sectors on the first surface and the second surface so that the total number of sectors recorded by both disk heads is constant;
A hard disk device comprising: The hard disk device further includes a nonvolatile memory,
The controller is
Means for detecting defective sectors of the recording disk;
An alternative sector holding means for securing an alternative sector area corresponding to the defective sector in the nonvolatile memory;
The recording control means controls to allocate the number of sectors on the first surface and the second surface including the alternative sector area so that the total number of sectors recorded by both disk heads is constant. The hard disk device according to claim 1, wherein: The two disk heads are each composed of two disk heads for reading and writing on both sides of the magnetic disk,
The controller further has a head selecting means for selecting any one of the disk heads for reading and writing on both sides.
3. The hard disk device according to claim 1, wherein the recording control unit controls simultaneous recording of the two disk heads selected by the head selecting unit.

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