Magnetic disk device and method
AssigneesKabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
InventorsHitoshi Hasegawa, Hiroyuki Takeda
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Abstract
According to an embodiment, upon a failure in detection of a servo mark from servo data recorded in a first normal servo sector in a write operation, a controller of a magnetic disk device stops a write operation. Then, the controller demodulates the servo data including the servo mark, for the servo data recorded in a first short servo sector being a short servo sector immediately before the first normal servo sector, and resumes the write operation from a data area immediately after the first normal servo sector.
Claims9
A magnetic disk device comprising:
- a magnetic disk that includes a spaced circumferential arrangement of a plurality of first servo sectors recording servo data including a servo mark and a burst pattern recorded after the servo mark in a circumferential write/read direction, and includes a plurality of data areas each provided between two first servo sectors adjacent in a circumferential direction, the plurality of first servo sectors including a plurality of second servo sectors and a plurality of third servo sectors, M (where M is an integer of 1 or more) third servo sectors of the plurality of third servo sectors being arranged between two adjacent second servo sectors of the plurality of second servo sectors;
- a magnetic head;
- and
- a controller that
- while performing first demodulation for the servo data recorded in each of the plurality of second servo sectors and second demodulation for the servo data recorded in each of the plurality of third servo sectors, writes data for the plurality of data areas by using the magnetic head, the first demodulation being an operation of detecting the servo mark and demodulating the burst pattern, the second demodulation being an operation of demodulating the burst pattern without detecting the servo mark, and
- upon a failure in detection of the servo mark in the first demodulation for the servo data recorded in a fourth servo sector being one of the plurality of second servo sectors,
- stops writing the data,
- performs the first demodulation for the servo data recorded in a fifth servo sector being a third servo sector immediately before the fourth servo sector in the write/read direction, of the plurality of third servo sectors, and
- starts writing the data from a data area immediately after the fourth servo sector of the plurality of data areas, when the magnetic head reaches the fourth servo sector after the first demodulation for the servo data recorded in the fifth servo sector.
A magnetic disk device comprising:
- a magnetic disk that includes a spaced circumferential arrangement of a plurality of first servo sectors recording servo data including a servo mark and a burst pattern recorded after the servo mark in a circumferential write/read direction, and includes a plurality of data areas each provided between two first servo sectors adjacent in a circumferential direction, the plurality of first servo sectors including a plurality of second servo sectors and a plurality of third servo sectors, M (where M is an integer of 1 or more) third servo sectors of the plurality of third servo sectors being arranged between two adjacent second servo sectors of the plurality of second servo sectors;
- a magnetic head;
- and
- a controller that
- while performing first demodulation for the servo data recorded in each of the plurality of second servo sectors and second demodulation for the servo data recorded in each of the plurality of third servo sectors, writes data for the plurality of data areas by using the magnetic head, the first demodulation being an operation of detecting the servo mark and demodulating the burst pattern, the second demodulation being an operation of demodulating the burst pattern without detecting the servo mark, and
- performs the first demodulation for the servo data recorded on one of the plurality of third servo sectors, upon retry of writing data to the plurality of data areas.
A method of writing data to a magnetic disk that includes a spaced circumferential arrangement of a plurality of first servo sectors recording servo data including a servo mark and a burst pattern recorded after the servo mark in a circumferential write/read direction, and includes a plurality of data areas each provided between two first servo sectors adjacent in a circumferential direction, the plurality of first servo sectors including a plurality of second servo sectors and a plurality of third servo sectors, M (where M is an integer of 1 or more) third servo sectors of the plurality of third servo sectors being arranged between two adjacent second servo sectors of the plurality of second servo sectors, the method comprising:
- writing data for the plurality of data areas by using the magnetic head while performing first demodulation for the servo data recorded in each of the plurality of second servo sectors and second demodulation for the servo data recorded in each of the plurality of third servo sectors, the first demodulation being an operation of detecting the servo mark and demodulating the burst pattern, the second demodulation being an operation of demodulating the burst pattern without detecting the servo mark;
- and
- upon a failure in detection of the servo mark in the first demodulation for the servo data recorded in a fourth servo sector being one of the plurality of second servo sectors,
- stopping writing the data,
- performing the first demodulation for the servo data recorded in a fifth servo sector being a third servo sector immediately before the fourth servo sector in the write/read direction, of the plurality of third servo sectors, and
- starting writing the data from a data area immediately after the fourth servo sector of the plurality of data areas, when the magnetic head reaches the fourth servo sector after the first demodulation for the servo data recorded in the fifth servo sector.
Dependencies are inferred from the claim text.