Asynchronously sampling wide bi-phase codes

Dynamic magnetic information storage or retrieval – Converting an analog signal to digital form for recording;...

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C360S051000, C360S042000, C360S077080, C360S078140, C360S049000, C341S070000, C375S361000, C375S370000

Reexamination Certificate

active

06587291

ABSTRACT:

TECHNICAL FIELD
This invention relates generally to sampling data that includes wide bi-phase code symbols and, more particularly, to a disk drive that asynchronously samples information, such as burst correction values (BCVs) and servo information, stored as wide bi-phase code symbols.
BACKGROUND
A data storage disk in a disk drive contains data tracks and radial spokes (also called “wedges”). The data tracks contain substantive information and the spokes contain servo information and burst data. The spokes are used in positioning a transducer head on the disk.
More specifically, by reading the servo information and burst data recorded within the spokes, a disk drive head positioner servo system is able to estimate the position of the drive's data transducer head. The recorded servo information typically includes track (i.e., cylinder and head) addresses. Each circumferential data track on a disk surface has a unique track address, which is recorded in the spokes. The servo burst data are recorded on the disk for use in positioning the transducer head properly on a track.
Thus, when a disk drive is seeking to a radial track location, the track addresses are used as coarse positioning information to position the transducer head on a specific track. The servo bursts are used as fine positioning information to position the head at a desired radial location within the track specified by the servo information.
SUMMARY
In general, in one aspect, the invention is directed to sampling data with wide bi-phase code symbols. This aspect of the invention includes sampling a wide bi-phase code symbol in the data a number (N) of times to produce samples of data, selecting a subset of the samples, determining which sample in the subset of samples has a largest magnitude, and selecting a subset of samples in a subsequent wide bi-phase code symbol based on a sample in a previous subset that has the largest magnitude.
By sampling a first wide bi-phase code symbol and selecting samples in a subsequent wide bi-phase code symbol based on the previous sample, the invention facilitates asynchronous sampling, reducing the need for feedback loops and the like to provide timing.
This aspect may include one or more of the following features. The largest magnitude may correspond to a peak in the wide bi-phase code symbol. The subset of samples may include three samples. Determining which sample in the subset of samples has the largest magnitude may include identifying if a middle sample of the three samples has the largest magnitude. If the middle sample does not have the largest magnitude, the process may include moving in the data an equivalent of N±1 samples and sampling the subsequent wide bi-phase code symbol starting at a location corresponding to the equivalent of the N±1 samples.
The data may include servo information on a storage disk. The servo information may identify a track on the storage disk. The data may include burst correction values stored on a storage disk. A burst correction value is an offset used in positioning a reading device on a track of the storage disk. Wide bi-phase code is a code in which a zero is represented by data values comprising “++−−” and a one is represented by data values comprising “−−++”. The value of N may be greater than four, e.g., eight.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the following description, drawings and claims.


REFERENCES:
patent: 4920442 (1990-04-01), Dimmick
patent: 5005089 (1991-04-01), Thanos et al.
patent: 5084791 (1992-01-01), Thanos et al.
patent: 5341249 (1994-08-01), Abbott et al.
patent: 5384671 (1995-01-01), Fisher
patent: 5521945 (1996-05-01), Knudson
patent: 5661760 (1997-08-01), Patapoutian et al.
patent: 5818659 (1998-10-01), Cheung et al.
patent: 5862005 (1999-01-01), Leis et al.
patent: 6111710 (2000-08-01), Feyh et al.
patent: 6111712 (2000-08-01), Vishakhadatta et al.
patent: 6185174 (2001-02-01), Belser
patent: WO 98/16040 (1998-04-01), None
patent: WO 99/60566 (1999-11-01), None

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Asynchronously sampling wide bi-phase codes does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Asynchronously sampling wide bi-phase codes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Asynchronously sampling wide bi-phase codes will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3070741

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.