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Disk device and read error retry method of disk device

A magnetic disk device, a technology for reading errors, applied in recording/reproducing/deleting methods, digital signal error detection/correction, digital recording/reproducing, etc.

Active Publication Date: 2022-02-08
KK TOSHIBA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Sectors that are affected from the periphery due to drift write (Drift off write, DOW), adjacent track interference (ATI), etc., may experience a decrease in signal output, an increase in noise, and a central When reading data from an error sector in such a state, such as misalignment, it will become a state where a read error is likely to occur
Usually, the parameters used in various processes such as the read channel are adjusted to the optimum values ​​for each head and each zone (zone) before leaving the factory. However, in the case of an error sector, as described above, It is in a state that is very different from the initial state, so it has become a state that cannot be said to be the optimal parameter.

Method used

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  • Disk device and read error retry method of disk device
  • Disk device and read error retry method of disk device
  • Disk device and read error retry method of disk device

Examples

Experimental program
Comparison scheme
Effect test

no. 1 Embodiment approach

[0022] figure 1 It is a figure which shows an example of the structure of the magnetic disk drive 1 of 1st Embodiment.

[0023] Such as figure 1 As shown, the magnetic disk device 1 is configured as, for example, a hard disk drive (HDD). The magnetic disk device 1 includes a magnetic disk 2, a spindle motor (SPM) 3, an actuator 4, a voice coil motor (VCM) 5, a magnetic head 10, a head amplifier IC 11, an R / W channel 12, and a hard disk controller (HDC) as a control unit. 13. CPU (Central Processing Unit) 14, driver IC 15, and memory 16.

[0024] In addition, the magnetic disk device 1 can be connected to a host computer (host computer) 17 . The magnetic head 10 includes a write head (recording head: writer) 10W, a read head (reproduction head: reader) 10R, and a spin-torque oscillator (Spin-Torque-Oscillator: STO) 100 as a high-frequency oscillation element. In addition, the R / W channel 12, the HDC 13, and the CPU 14 may be integrated into a single-chip integrated circuit....

no. 2 Embodiment approach

[0060] When it is judged that there are no sectors above X (ST108: No), if the method of performing training reading to the wrong sector Err (ST110), for example, in order to perform 50 training reads on the wrong sector Err, It is necessary to rotate the disk 2 50 times, so it may take time to reach a timeout. In order to avoid such a situation, the second embodiment differs from the first embodiment in that the number of training reads is increased when no sector greater than X is found. In addition, the same code|symbol is attached|subjected to the same structure as 1st Embodiment.

[0061] Figure 10 is shown for the aforementioned image 3 A flow chart of an example when processing is added to retry processing for read errors. In this embodiment, in image 3 In the case of NO in step ST108, the processing of steps ST201 and ST202 is added, so the processing of steps ST201 and ST202 will be described.

[0062] When it is judged that there are no more than X sectors in...

no. 3 Embodiment approach

[0066] The third embodiment differs from the second embodiment in that, when no sector greater than X is found, the range of the fixed range W1 is expanded to increase the number of sectors to be searched. In addition, the same code|symbol is attached|subjected to the same structure as 1st Embodiment.

[0067] Figure 12 is shown for the aforementioned image 3 A flow chart of an example when processing is added to retry processing for read errors. In this embodiment, in image 3 In the case of NO in step ST108, the processing of step ST301 is added, so the processing of step ST301 will be described.

[0068] When it is determined that the searched sector does not exist within the track of X or more (ST108: NO), the HDC 13 expands the fixed range W1 to W2 (>W1) (ST301). Then, the process returns to step ST101. By expanding the fixed range W1 to the fixed range W2 in this way, the number of sectors having a BER value in the fixed range W2 relative to the BER value of the e...

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Abstract

Embodiments of the present invention provide a magnetic disk device and a read error retry method of the magnetic disk device that can efficiently relearn parameters and minimize retry time. A magnetic disk device according to an embodiment includes a read channel and a control unit. The read channel has circuitry to process the output from the read head. When a read error is detected from the output of the read channel, the control unit searches for a predetermined sector to be targeted for training reading when setting the parameters of the read channel, performs training reading on the searched sector, and passes the training Read to change the parameters of the circuit, and read the wrong sector again. Here, the predetermined sector is to measure the BER value of each sector in the track containing the erroneous sector and have a BER value within a certain range relative to the BER value of the erroneous sector. Sectors allocated consecutively over the number of sectors.

Description

[0001] This application enjoys the priority of the basic application based on Japanese Patent Application No. 2019-157085 (filing date: August 29, 2019). This application incorporates the entire content of the basic application by referring to this basic application. technical field [0002] Embodiments relate to a magnetic disk device and a read error retry method of the magnetic disk device. Background technique [0003] Sectors that are affected from the periphery due to drift write (Drift off write, DOW), adjacent track interference (ATI), etc., may experience a decrease in signal output, an increase in noise, and a central When data is read from an erroneous sector in such a state such as misalignment, a read error is likely to occur. Usually, the parameters used in various processes such as the read channel are adjusted to the optimum values ​​for each head and each zone (zone) before leaving the factory. However, in the case of an error sector, as described above, I...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G11B5/02G11B20/18
CPCG11B5/02G11B20/182G11B2020/183G11B20/1217G11B20/1816G11B2020/1232
Inventor 千叶宽幸
Owner KK TOSHIBA