Data storage device employing differential write data signal and differential write pattern signal

• US 9,368,132 B1
• Filed: 09/04/2015
• Issued: 06/14/2016
• Est. Priority Date: 09/04/2015
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Hogg, Dennis W.
• Primary Examiner(s): Hindi, Nabil
• Application Number:
  US14/846,019
• Time in Patent Office: 284 Days
• Field of Search: 360/22, 360/24, 360/25, 360/39, 360/55, 360/46
• US Class Current: 1/1
• CPC Class Codes: G11B 20/10018 analog processing for digital recording or reproduction G11B20/10037 - G11B20/10481 take precedence
• CPC Class Codes: G11B 20/14 using self-clocking codes
• CPC Class Codes: G11B 5/02 Recording, reproducing, or erasing methods; Read, write or erase circuits therefor

Abstract

A data storage device is disclosed comprising a head actuated over a disk. A first control circuit comprises a pattern detector configured to detect at least one pattern in write data and generate a corresponding multi-state signal, and a transmitter configured to transmit a first differential signal representing the write data and a second differential signal representing the multi-state signal. A second control circuit comprises a receiver configured to receive the first differential signal and the second differential signal, and a write driver configured to generate a write current applied to the head based on the first differential signal and configured to adjust at least one property of the write current based on the second differential signal.

Claims

1. A data storage device comprising:

a disk;

a head actuated over the disk;

a first control circuit comprising;

a pattern detector configured to detect at least one pattern in write data and generate a corresponding multi-state signal; and

a transmitter configured to transmit a first differential signal representing the write data and a second differential signal representing the multi-state signal; and

a second control circuit comprising;

a receiver configured to receive the first differential signal and the second differential signal; and

a write driver configured to generate a write current applied to the head based on the first differential signal and configured to adjust at least one property of the write current based on the second differential signal.

2. The data storage device as recited in claim 1, wherein the pattern detector is configured to detect at least three different patterns in the write data and generate the corresponding multi-state signal to represent each detected pattern.

3. The data storage device as recited in claim 2, wherein the three different patterns comprise a 0T pattern, a 1T pattern, and a 2T pattern.

4. The data storage device as recited in claim 1, wherein the at least one property of the write current comprises an amplitude of the write current.

5. The data storage device as recited in claim 1, wherein the at least one property of the write current comprises an overshoot duration of the write current.

6. The data storage device as recited in claim 1, wherein the first control circuit is configured to transmit the second differential signal substantially synchronous with the first differential signal.

7. The data storage device as recited in claim 1, wherein the second control circuit further comprises a decoder configured to decode the second differential signal.

8. A method of operating a data storage device, the method comprising:

detecting at least one pattern in write data and generating a corresponding multi-state signal;

transmitting a first differential signal representing the write data and a second differential signal representing the multi-state signal;

receiving the first differential signal and the second differential signal; and

generating a write current applied to a head actuated over a disk based on the first differential signal and adjusting at least one property of the write current based on the second differential signal.

9. The method as recited in claim 8, wherein detecting at least one pattern comprises detecting at least three different patterns in the write data and generating the corresponding multi-state signal to represent each detected pattern.

10. The method as recited in claim 9, wherein the three different patterns comprise a 0T pattern, a 1T pattern, and a 2T pattern.

11. The method as recited in claim 8, wherein the at least one property of the write current comprises an amplitude of the write current.

12. The method as recited in claim 8, wherein the at least one property of the write current comprises an overshoot duration of the write current.

13. The method as recited in claim 8, further comprising transmitting the second differential signal substantially synchronous with the first differential signal.

14. The method as recited in claim 8, further comprising decoding the second differential signal.