US 2008/0304173 A1 · MAGNETIC RECORDING DISK DRIVE WITH PATTERNED MEDIA AND SYSTEM FOR CLOCKING WRITE DATA

Abstract

A system and method accurately clocks write data to the discrete data blocks in a patterned media disk drive. The precise time intervals between successive timing marks in the data tracks are measured by a timing mark detector that counts the integer number of write clock cycles between successive timing marks and the fractional part of a write clock cycle by detecting the phase difference between a timing mark and a reference signal. The resulting timing error is output to a write clock compensator. The write clock is capable of generating equally spaced primary phases and phases intermediate the primary phases. The compensator includes a phase rotator that controls which write clock phase is selected for output. The value in a phase register of the compensator is used to control the phase rotator to advance or retard the write clock phase, and thus to adjust its frequency and phase so as to be synchronized for writing to the data blocks.

Claims22

Dependent claims

A magnetic recording disk drive comprising:

a rotatable magnetic recording disk having a plurality of generally circular data tracks, each data track patterned into discrete magnetizable data blocks, and a plurality of generally equally angularly spaced timing marks extending generally radially across the data tracks;
a write head for generating write pulses to magnetize the discrete data blocks;
a write clock coupled to the write head for controlling the write pulses to the discrete data blocks;
a read head for sensing the timing marks;
timing mark detection circuitry coupled to the read head for measuring a write clock timing error between successive timing marks during rotation of the disk;
and
timing error compensation circuitry responsive to the timing error for adjusting the write clock.

4 more elements

A method for synchronizing the writing of data on discrete magnetizable data blocks of a patterned media disk drive, the disk drive having (a) a rotatable magnetic recording disk having a plurality of generally circular data tracks, each data track patterned into discrete magnetizable data blocks, and a plurality of generally equally angularly spaced timing marks extending generally radially across the data tracks;

(b) a write head for generating write pulses to magnetize the discrete data blocks;
(c) a write clock coupled to the write head for controlling the write pulses to the discrete data blocks;
(d) a read head for sensing the timing marks;
(e) a processor for receiving timing mark signals from the read head and generating timing compensation signals to the write clock;
and (f) memory coupled to the processor and containing a program of instructions readable by the processor;
the processor-implemented method comprising:
measuring the time between successive timing mark signals;
calculating a timing error from the measured time and a predetermined time value;
and
adjusting the timing of the write clock in response to the calculated timing error.

7 more elements

Dependencies are inferred from the claim text.

Magnetic recording disk drive with patterned media and system for clocking write data

Life of this patent

Magnetic recording disk drive with patterned media and system for clocking write data

Life of this patent

Abstract

Claims22