US 12,361,970 B1Granted

Parallel self-servo write circuitry in a data storage device

AssigneeWestern Digital Technologies, Inc.

InventorsGuoxiao Guo, Yanning Liu, Joey M. Poss, Ryan Mayo, Richard Conway, Scott A Ottele, Charles A. Park

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Abstract

Example circuits, data storage devices, and methods to provide parallel self-servo write in a data storage device are described. The data storage device may include multiple heads actuated over respective surfaces of storage media and at least two preamplifiers and read paths to a channel circuit. Control circuitry may select heads connected through different preamplifiers for parallel self-servo write and receive read signals from the selected heads in parallel. These read signals, which may be based on self-servo write reference spirals previously written to the storage media, may be used to determine respective position error signals for the two heads and control their respective positions with corresponding control signals to a shared voice control motor and respective micro and/or milli actuators on the arms supporting the heads.

Claims20

Dependent claims

A data storage device, comprising:

a first head actuated over a first storage medium surface, wherein:
the first head comprises a first plurality of read elements;
and
each read element of the first plurality of read elements is configured to generate a corresponding read signal responsive to the first storage medium surface;
a second head actuated over a second storage medium surface, wherein:
the second head comprises a second plurality of read elements;
and
each read element of the second plurality of read elements is configured to generate a corresponding read signal responsive to the second storage medium surface;
and
control circuitry configured to:
select a first corresponding read signal from the first plurality of read elements;
select a second corresponding read signal from the second plurality of read elements;
receive, by a channel circuit, the first corresponding read signal and the second corresponding read signal in parallel;
determine, by the channel circuit, a first position error signal from the first corresponding read signal;
determine, by the channel circuit, a second position error signal from the second corresponding read signal;
control, responsive to the first position error signal, a first position of the first head;
control, responsive to the second position error signal, a second position of the second head;
write, responsive to the first position relative to a first self-servo write reference spiral being within a first error tolerance value, a first servo pattern at the first head;
and
write, responsive to the second position relative to a second self-servo write reference spiral is within a second error tolerance value, a second servo pattern at the second head.

17 more elements

A method comprising:

actuating a first head over a first storage medium surface in a data storage device, wherein:
the first head comprises a first plurality of read elements;
and
each read element of the first plurality of read elements is configured to generate a corresponding read signal responsive to the first storage medium surface;
actuating a second head over a second storage medium surface in the data storage device, wherein:
the second head comprises a second plurality of read elements;
and
each read element of the second plurality of read elements is configured to generate a corresponding read signal responsive to the second storage medium surface;
and
selecting a first corresponding read signal from the first plurality of read elements;
selecting a second corresponding read signal from the second plurality of read elements;
receiving, by a channel circuit in the data storage device, the first corresponding read signal and the second corresponding read signal in parallel;
determining, by the channel circuit, a first position error signal from the first corresponding read signal;
determining, by the channel circuit, a second position error signal from the second corresponding read signal;
controlling, responsive to the first position error signal, a first position of the first head;
controlling, responsive to the second position error signal, a second position of the second head;
writing, responsive to the first position relative to a first self-servo write reference spiral being within a first error tolerance value, a first servo pattern at the first head;
and
writing, responsive to the second position relative to a second self-servo write reference spiral is within a second error tolerance value, a second servo pattern at the second head.

16 more elements

Dependencies are inferred from the claim text.