Systems and methods for format efficient sector fragment processing

1. A data processing system, the system comprising:

a data processing circuit operable to receive a set of data having at least a first fragment and a second fragment, wherein the first fragment includes an initial alignment data and the second fragment includes a subsequent alignment data;

a zero phase start calculation circuit operable to calculate a zero phase start output based upon the initial alignment data;

a distance counter operable to count a distance between elements of the initial alignment data and corresponding elements of the subsequent alignment data; and

a zero phase start alignment circuit operable to modify a portion of the zero phase start output to yield a modified zero phase start output based at least in part on the distance, wherein processing of the subsequent alignment data uses the modified zero phase output.

2. The data processing system of claim 1 , wherein the initial alignment data includes a full preamble segment, and the subsequent alignment data includes a short preamble segment.

3. The data processing system of claim 2 , wherein the full preamble segment and the short preamble segment include repeating patterns selected from a group consisting of: a 3T pattern, a 4T pattern, and a 5T pattern.

4. The data processing system of claim 1 , wherein the system further comprises:

a AB filter operable to generate a phase offset version of the initial alignment data, wherein the phase offset is snapped to a first phase adjustment derived from the zero phase start output during processing of the initial alignment data, and wherein the phase offset is initialized to a second phase adjustment derived from the modified zero phase start output during processing of the subsequent alignment data.

5. The data processing system of claim 4 , wherein the system further comprises:

a zero crossing and slope selection circuit operable to: select a first slope and a first zero crossing based upon the zero phase start output during processing of the initial alignment data; and select a second slope and a second zero crossing based upon the modified zero phase start output during processing of the subsequent alignment data; and

an acquire timing error correction circuit operable to:

generate a first clock adjustment value based upon a combination of the first slope, the first zero crossing, and a first instance of the phase offset version of the initial alignment data during processing of the initial alignment data; and

generate a second clock adjustment value based upon a combination of the second slope, the second zero crossing, and a second instance of the phase offset version of the initial alignment data during processing of the subsequent alignment data.

6. The data processing system of claim 5 , wherein the system further comprises:

an analog to digital converter sample clock adjustment circuit operable to:

modify an analog to digital converter sample clock based upon the first clock adjustment value during processing of the initial alignment data; and

modify the analog to digital converter sample clock based upon the second clock adjustment value during processing of the subsequent alignment data; and

an analog to digital converter circuit operable to generate a series of digital samples from an analog input synchronous to the analog to digital converter sample clock, wherein the set of data is derived from the series of digital samples.

7. The data processing system of claim 1 , wherein the data processing circuit is a first data processing circuit, wherein the set of data is a first set of data derived from a first read head, wherein the zero phase start circuit is a first zero phase start circuit, wherein the zero phase start output is a first zero phase output; and wherein the system further comprises:

a second data processing circuit operable to receive a second set of data having at least the first fragment and the second fragment, wherein the second set of data is derived from a second read head;

a second zero phase start calculation circuit operable to calculate a second zero phase start output based upon the initial alignment data;

a zero phase start output combining circuit operable to combine the first zero phase start output and the second zero phase start output to yield a combined zero phase output; and

wherein the zero phase start alignment circuit is operable to modify a portion of the combined zero phase start output to yield the modified zero phase start output based at least in part on the distance, wherein processing of the subsequent alignment data uses the modified zero phase output.

8. The data processing system of claim 1 , wherein the zero phase start alignment circuit is operable to:

calculate a modulo three of the distance;

add the module three to a hexant of the zero phase start output to yield to yield an interim zero phase output; and

force the interim zero phase start output into an expected range to yield a hexant of the modified zero phase output.

9. The data processing system of claim 1 , wherein the system is implemented as part of an integrated circuit.

10. The data processing system of claim 1 , wherein the system is implemented as part of a storage device, and wherein the storage device comprises:

a storage medium storing information corresponding to the set of data; and

a read/write head assembly disposed in relation to the storage medium.

11. A method for data processing, the method comprising:

receiving a set of data having at least a first fragment and a second fragment, wherein the first fragment includes an initial alignment data and the second fragment includes a subsequent alignment data;

calculating a zero phase start based upon the initial alignment data using a zero phase start calculation circuit;

counting a distance between elements of the initial alignment data and corresponding elements of the subsequent alignment data;

modifying a portion of the zero phase start output to yield a modified zero phase start output based at least in part on the distance; and

processing the subsequent alignment data using the modified zero phase output.

12. The method of claim 11 , wherein the initial alignment data includes a full preamble segment, and the subsequent alignment data includes a short preamble segment; and wherein the full preamble segment and the short preamble segment include repeating patterns selected from a group consisting of: a 3T pattern, a 4T pattern, and a 5T pattern.

13. The method of claim 11 , the method further comprising:

generating a phase offset version of the initial alignment data, wherein the phase offset is snapped to a first phase adjustment derived from the zero phase start output during processing of the initial alignment data, and wherein the phase offset is initialized to a second phase adjustment derived from the modified zero phase start output during processing of the subsequent alignment data.

14. The method of claim 13 , the method further comprising:

selecting a first slope and a first zero crossing based upon the zero phase start output during processing of the initial alignment data;

selecting a second slope and a second zero crossing based upon the modified zero phase start output during processing of the subsequent alignment data;

generating a first clock adjustment value based upon a combination of the first slope, the first zero crossing, and a first instance of the phase offset version of the initial alignment data during processing of the initial alignment data; and

generating a second clock adjustment value based upon a combination of the second slope, the second zero crossing, and a second instance of the phase offset version of the initial alignment data during processing of the subsequent alignment data.

15. The method of claim 14 , the method further comprising:

modifying an analog to digital converter sample clock based upon the first clock adjustment value during processing of the initial alignment data;

modifying the analog to digital converter sample clock based upon the second clock adjustment value during processing of the subsequent alignment data; and

generating a series of digital samples from an analog input synchronous to the analog to digital converter sample clock, wherein the set of data is derived from the series of digital samples.

16. The method of claim 11 , wherein modifying the portion of the zero phase start output to yield the modified zero phase start output comprises:

calculating a modulo three of the distance;

adding the module three to a hexant of the zero phase start output to yield to yield an interim zero phase output; and

forcing the interim zero phase start output into an expected range to yield a hexant of the modified zero phase output.

17. A data processing system, the system comprising:

a first data processing circuit operable to receive a first set of data having at least a first fragment and a second fragment, wherein the first fragment includes an initial alignment data and the second fragment includes a subsequent alignment data, and wherein the first set of data is derived from a first read head;

a first zero phase start calculation circuit operable to calculate a first zero phase start output based upon the initial alignment data from the first set of data;

a second data processing circuit operable to receive a second set of data having at least the first fragment and the second fragment, wherein the first fragment includes the initial alignment data and the second fragment includes the subsequent alignment data, and wherein the second set of data is derived from a second read head;

a second zero phase start calculation circuit operable to calculate a second zero phase start output based upon the initial alignment data from the second set of data;

a zero phase start output combining circuit operable to combine the first zero phase start output and the second zero phase start output to yield a combined zero phase output

a distance counter operable to count a distance between elements of the initial alignment data and corresponding elements of the subsequent alignment data; and

a zero phase start alignment circuit operable to modify a portion of the combined zero phase start output to yield a modified zero phase start output based at least in part on the distance, wherein processing of the subsequent alignment data uses the modified zero phase output.

18. The system of claim 17 , wherein the zero phase start alignment circuit is operable to:

calculate a modulo three of the distance;

add the module three to a hexant of the zero phase start output to yield to yield an interim zero phase output; and

force the interim zero phase start output into an expected range to yield a hexant of the modified zero phase output.

19. The system of claim 17 , wherein the system further comprises:

a AB filter operable to generate a phase offset version of the initial alignment data, wherein the phase offset is snapped to a first phase adjustment derived from the first zero phase start output during processing of the initial alignment data, and wherein the phase offset is initialized to a second phase adjustment derived from the modified zero phase start output during processing of the subsequent alignment data.

20. The system of claim 19 , wherein the system further comprises:

a zero crossing and slope selection circuit operable to: select a first slope and a first zero crossing based upon the combined zero phase start output during processing of the initial alignment data; and select a second slope and a second zero crossing based upon the modified zero phase start output during processing of the subsequent alignment data;

an acquire timing error correction circuit operable to:

generate a first clock adjustment value based upon a combination of the first slope, the first zero crossing, and a first instance of the phase offset version of the initial alignment data during processing of the initial alignment data; and

generate a second clock adjustment value based upon a combination of the second slope, the second zero crossing, and a second instance of the phase offset version of the initial alignment data during processing of the subsequent alignment data;

an analog to digital converter sample clock adjustment circuit operable to:

modify an analog to digital converter sample clock based upon the first clock adjustment value during processing of the initial alignment data; and

modify the analog to digital converter sample clock based upon the second clock adjustment value during processing of the subsequent alignment data; and

an analog to digital converter circuit operable to generate a series of digital samples from an analog input synchronous to the analog to digital converter sample clock, wherein the set of data is derived from the series of digital samples.