Medium drive and method of generating a defect map for registering positions of defects on a medium

Abstract

A hard disk drive (HDD) according to an embodiment of the present invention uses three primary defect map (PDM) formats: a single-sector entry format; a multi-sector entry format; and a two-dimensional sector entry format. Methods of registering defective sectors in each such format are illustrated. Defects can be appropriately registered in a limited RAM capacity by selecting an appropriate format according to states of the defects on a magnetic disk.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing schematically an entire configuration of a hard disk drive (HDD) according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a data format of data written on a magnetic disk according to an embodiment of the present invention.

FIG. 3 is a block diagram showing schematically a configuration used to manage defective sectors under normal operating conditions of the HDD according to an embodiment of the present invention.

FIGS. 4( a) to 4(c) schematically show methods of registering defective sectors in each PDM format according to an embodiment of the present invention, wherein FIG. 4(a) schematically shows a single-sector entry format, FIG. 4(b) a multi-sector entry format, and FIG. 4(c) a two-dimensional sector entry format.

FIG. 5 schematically shows an example of a PDM of the single-sector entry format according to an embodiment of the present invention.

FIG. 6 schematically shows an example of a PDM of the multi-sector entry format according to an embodiment of the present invention.

FIG. 7 schematically shows an example of a PDM of the two-dimensional sector entry format according to an embodiment of the present invention.

FIG. 8 is a diagram showing, for each PDM format according to an embodiment of the present invention, the kind of data stored in one entry and the maximum number of defective sectors that can be registered in one entry.

FIG. 9 shows an example of the number of entries that can be stored in each PDM format.

FIG. 10 is a block diagram showing schematically a configuration used to generate a PDM and register defective sectors on the PDM according to an embodiment of the present invention.

FIG. 11 is a flow chart that shows registration of defective sectors on a PDM in a SRST according to an embodiment of the present invention.

Claims

1. A medium drive comprising: a medium for recording data;a memory for storing a defect map on which positions of defects on the medium are to be registered; anda controller for determining a format on the basis of the defects detected on the medium, and generating the defect map in accordance with the determined format.

2. The medium drive according to claim 1, wherein the controller executes defect detection tests on the medium and determine a format based on the defects that have been detected during the defect detection tests.

3. The medium drive according to claim 1, wherein the controller selects one format from a plurality of formats each different in the number of defect positions that can be registered in one entry and in the amount of data used for one entry, and generates the defect map in accordance with the selected format.

4. The medium drive according to claim 3, wherein: the plurality of formats include a first format and a second format that is larger than the first format in terms of the number of defect positions that can be registered in one entry and in terms of the amount of data that used for one entry; andthe controller uses the first format if the number of entries registered in a defect map based on the first format is equal to or smaller than a reference number, and uses the second format if the reference number is exceeded.

5. The medium drive according to claim 4, wherein the reference number is a total number of entries in the defect map based on the first format.

6. The medium drive according to claim 4, wherein: the plurality of formats further include a third format larger than the second format in terms of the number of defect positions that can be registered in one entry and in terms of the amount of data used for one entry; andthe controller uses the third format if the number of entries registered in a defect map based on the second format exceeds a reference number.

7. The medium drive according to claim 4, wherein the controller generates a defect map based on the first format, registers defect positions, and if the number of entries registered exceeds a reference number, changes the defect map of the first format to a defect map of the second format.

8. The medium drive according to claim 7, wherein: the plurality of formats further include a third format larger than the second format in terms of the number of defect positions that can be registered in one entry and in terms of the amount of data used for one entry; andif the number of entries registered in the defect map based on the second format exceeds a reference number, the controller changes the defect map of the second format to a defect map of the third format.

9. The medium drive according to claim 3, wherein: in the first format, one defect address is registered in one entry; andin the second format, a defect address that is a reference and the number of defect addresses that is one-dimensionally continuous are registered in one entry.

10. The medium drive according to claim 6, wherein, in the third format, a defect address that is a reference, the number of defect addresses that are continuous in a first direction, and the number of defect addresses that are continuous in a second direction different from the first direction are registered in one entry.

11. A method of generating a defect map on which positions of defects on a medium are registered, the method comprising the steps of: detecting the defects on the medium;determining a format based on the defects detected on the medium;generating the defect map in accordance with the determined format; andregistering, on the generated defect map, the positions of the defects detected on the medium.

12. The method according to claim 11, further comprising the steps of: generating a first defect map based on a first format and registering defect positions on the first defect map;if the number of entries registered on the first defect map exceeds a reference number, generating a second defect map based on a second format larger than the first format in terms of the number of defect positions that can be registered in one entry and in terms of the amount of data used for one entry; andregistering, on the second defect map, the defects that have been detected on the medium.