Phase slip recovery

• US 10,446,185 B2
• Filed: 09/18/2017
• Issued: 10/15/2019
• Est. Priority Date: 09/18/2017
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Michel, Richard P., Link, Michael J., Kharpate, Anand R., Xu, Guofang
• Primary Examiner(s): Alphonse, Fritz
• Application Number:
  US15/707,396
• Publication Number:
  US 20190088286A1
• Time in Patent Office: 757 Days
• Field of Search: 714769
• CPC Class Codes: G06F 11/08 Error detection or correction by redundancy in data representation, e.g. by using checking codes
• CPC Class Codes: G11B 20/10268 bit detection or demodulation methods
• CPC Class Codes: G11B 20/10527 Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: G11B 20/18 Error detection or correction; Testing , e.g. of drop-outs
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence

Abstract

Systems, devices, and method for phase slip recovery may include reading a plurality of data portions of a data block and positioning a mask over one or more data portions of the data block. The data portions following the mask may be shifted to provide a masked, reframed data block, and then the data block may be attempted to be decoded, which may be repeated until the data block is decoded.

Claims

1. A device comprising:

a storage medium comprising a plurality of data blocks, wherein each of the data blocks comprises a plurality of data portions; and

a controller comprising one or more processors, the controller operably coupled to the storage medium and configured to;

read a plurality of data portions comprising a data block and at least one buffered data portion following the data block from the storage medium, the data block comprising a phase slip;

identify the location of the phase slip within the data block;

position a mask on one or more data portions within the data block including the location of the phase slip; and

until the masked data block is decoded, perform the following;

shift the plurality of data portions following the location of the phase slip to provide a masked, reframed data block, and

attempt to decode the masked, reframed data block.

2. The device of claim 1, wherein the storage medium and the controller provide heat-assisted magnetic recording (HAMR).

3. The device of claim 1, wherein the mask is centered on one or more data portions within the data block to be centered about the location of the phase slip.

4. The device of claim 1, wherein the mask defines a size that is less than or equal to the burst correction ability of the controller.

5. The device of claim 1, wherein the shifting of the plurality of data portions following the location of the phase slip to provide a masked, reframed data block and the attempting to decode the masked, reframed data block comprises:

shifting the plurality of data portions following the location of the phase slip to an initial shift location at the beginning of the mask to provide an initial masked, reframed data block and attempting to decode the initial masked, reframed data block; and

until the masked, reframed data block is decoded, performing the following;

shifting the plurality of data portions following the location of the phase slip to one or more subsequent shift locations that are different from the previous shift location to provide subsequent masked, reframed data blocks, and

attempting to decode the subsequent masked, reframed data blocks.

6. The device of claim 5, wherein each of the one or more subsequent shift locations is one data portion away from the previous shift location.

7. The device of claim 1, wherein the data block is a sector.

8. A device comprising:

a storage medium comprising a plurality of data blocks, wherein each of the data blocks comprises a plurality of data portions; and

a controller comprising one or more processors, the controller operably coupled to the storage medium and configured to;

read a plurality of data portions comprising a data block and at least one buffered data portion following the data block from the storage medium, the data block comprising a phase slip;

position a mask on one or more data portions at one or more locations within the data block; and

for each location that the mask is positioned, and until the masked data block is decoded or an amount of shifts exceeds the size of the mask, perform the following;

shift the plurality of data portions following a middle of the mask to provide a masked, reframed data block, and

attempt to decode the masked, reframed data block.

9. The device of claim 8, wherein the storage medium and the controller provide heat-assisted magnetic recording (HAMR).

10. The device of claim 8, wherein positioning the mask on one or more data portions at one or more locations within the data block comprises:

positioning the mask on one or more data portions at an initial location within the data block; and

positioning the mask on one or more data portions at a subsequent location different than the initial location within the data block until the masked, reframed data block is decoded.

11. The device of claim 8, wherein the mask defines a size that is less than or equal to the burst correction ability of the controller.

12. The device of claim 8, wherein the shifting of the plurality of data portions following a middle of the mask to provide a masked, reframed data block and the attempting to decode the masked, reframed data block comprises:

shifting the plurality of data portions following the middle of the mask to an initial shift location at the beginning of the mask to provide an initial masked, reframed data block and attempting to decode the initial masked, reframed data block; and

until the masked, reframed data block is decoded or the amount of shifts exceeds the size of the mask, performing the following;

shifting the plurality of data portions following the middle of the mask to one or more subsequent shift locations that are different from the previous shift location to provide subsequent masked, reframed data blocks, and

attempting to decode the subsequent masked, reframed data blocks.

13. The device of claim 12, wherein each of the one or more subsequent shift locations is one data portion away from the previous shift location.

14. The device of claim 8, wherein the data block is a sector.

15. A system comprising:

a storage medium comprising a plurality of data blocks, wherein each of the data blocks comprises a plurality of data portions; and

a controller comprising one or more processors, the controller operably coupled to the storage medium and configured to;

read a plurality of data portions comprising a data block and at least one buffered data portion following the data block from the storage medium, the data block comprising a phase slip; and

until the masked data block is decoded, perform the following;

generate one or more masked, reframed data blocks based on the plurality of data portions, and

attempt to decode each of the one or more masked, reframed data blocks until the masked, reframed data block is decoded.

16. The system of claim 15, wherein the storage medium and the controller provide heat-assisted magnetic recording (HAMR).

17. The system of claim 15, wherein generating one or more masked, reframed data blocks based on the plurality of data portions comprises:

identifying the location of the phase slip within the data block;

positioning a mask on one or more data portions within the data block including the location of the phase slip;

shifting the plurality of data portions following the location of the phase slip to an initial shift location at the beginning of the mask to provide an initial masked, reframed data block; and

until the masked, reframed data block is decoded, shifting the plurality of data portions following the location of the phase slip to one or more subsequent shift locations that are different from the previous shift location to provide subsequent masked, reframed data blocks.

18. The system of claim 15, wherein generating one or more masked, reframed data blocks based on the plurality of data portions comprises:

positioning a mask on one or more data portions at an initial location within the data block to provide an initial masked, reframed data block;

positioning the mask on one or more data portions at one or more subsequent locations different than the previous location within the data block to provide subsequent masked, reframed data blocks.

19. The system of claim 15, wherein generating one or more masked, reframed data blocks based on the plurality of data portions comprises:

shifting the plurality of data portions following the middle of the mask to an initial shift location at the beginning of the mask to provide an initial masked, reframed data block; and

shifting the plurality of data portions following the middle of the mask to one or more subsequent shift locations that are different from the previous shift location to provide subsequent masked, reframed data blocks.

20. The system of claim 15, wherein the data block is a sector.