Read after write enhancement for bit patterned media

1. A method for detecting write synchronization errors, the method comprising:

writing data to a bit-patterned media with a read/write head responsive to a write clock, the bit-patterned media includes normally-positioned bit-islands, early-positioned bit-islands shifted in a first direction relative to the normally-positioned bit-islands, and late-positioned bit-islands shifted in a second direction relative to the normally-positioned bit-islands;

reading the written data with a first reader trailing a writer on the read/write head;

detecting write synchronization errors associated with the write clock being out of phase with the location of the normally-positioned, early-positioned, or late-positioned bit-islands on the bit-patterned media; and

modifying the phase of the write clock based on detected write synchronization errors.

2. The method of claim 1 , wherein the first reader provides read after write (RAW) verification of the data written by the writer.

3. The method of claim 2 , wherein a distance separating the writer from the first reader is minimized to reduce effects of skew between the writer and the first reader such that the first reader is positioned as close as possible to a track written by the writer.

4. The method of claim 2 , wherein reading data written to the bit-patterned media includes:

subtracting noise associated with the data currently being written by the writer to reduce cross-talk between the first reader and the writer.

5. The method of claim 2 , wherein reading data written to the bit-patterned media includes:

reading only that data written to the bit-patterned media that passes under the first reader following the writer ceasing to write data to the bit-patterned media.

6. The method of claim 1 , further comprising

a second reader behind the writer and radially offset from the first reader such that the first reader and the second reader provide read after write (RAW) verification of the data written by the writer.

7. The method of claim 6 , further including:

generating error positioning signal regarding the radial position of the read/write head based on a ratio of magnitudes of on-track signals measured by both the first reader and the second reader.

8. The method of claim 6 , further including:

generating error positioning data regarding the radial position of the read/write head based on a magnitude of cross talk relative to an on-track signal as measured by both the first reader and the second reader.

9. The method of claim 1 , wherein reading data written to the bit-patterned media to detect write synchronization errors associated with the write clock being out of phase with the location of bit-islands on the bit-patterned media includes:

reading the data written to the early-positioned bit-islands and the data written to the late-positioned bit-islands to detect write synchronization errors based on the success or failure to write bits to either the early-positioned bit-islands or the late-positioned bit-islands.

10. The method of claim 9 , wherein modifying the phase of the write clock based on detected write synchronization errors includes:

modifying the phase of the write clock based on the success or failure to write bits to either the early-positioned bit-islands or the late-positioned bit-island such that the write clock is properly phased with the normally-positioned bit-islands of the bit-patterned media.

11. The method of claim 1 , wherein writing data to the bit-patterned media with a write clock includes:

modifying the phase of the write clock to include a normally-phased write clock, an early-phased write clock, and a late-phased write clock.

12. The method of claim 11 , wherein reading data written to the bit-patterned media to detect write synchronization errors includes:

reading the data written to the bit-patterned media with the early-phased write clock and the data written to the bit-patterned media with the late-phased write clock to detect write synchronization errors based on the success or failure to write bits with the early-phased write clock or the late-phased write clock.

13. The method of claim 12 , wherein modifying the phase of the write clock based on detected write synchronization errors includes:

modifying the phase of the write clock based on the success or failure to write bits with the early-phased write clock or the late-phased write clock.

14. A read/write head for providing read after write functionality, the read/write head comprising:

a writer for writing data to a bit patterned media;

a first reader for reading data stored to the bit patterned media and positioned behind the writer such that the first reader can provide real-time verification of data written by the writer;

a synthetic anti-ferromagnetic write shield located between the first reader and the writer; and

a synthetic anti-ferromagnetic reader shield located between the write shield and the first reader.

15. The read/write head of claim 14 , wherein a distance separating the write from the first reader is minimized to reduce effects of skew between the writer and the first reader such that the first reader is positioned as close as possible to a track written by the writer.

16. The read/write head of claim 14 , wherein the cross-talk between the writer and the first reader is reduced by subtracting noise associated with the data currently being written by the writer.

17. The read/write head of claim 14 , wherein the first reader only reads data subsequent to the write head ceasing write operations, wherein the first reader verifies all remaining data that passes under the first reader.

18. The read/write head claim of 14 , further including:

a second reader offset radially from the first reader, wherein the first reader and the second reader work in conjunction to read the data written by the writer in a ganged read after write configuration.

19. The read/write head of claim 18 , wherein an error positioning signal regarding the radial position of the read/write head is determined based on a ratio of off-track signals measured by the first reader and the second reader.

20. The read/write head of claim 18 , wherein error positioning data regarding the radial position of the read/write head is determined based on a ratio of on-track signals measured by the first reader and the second reader.