Auxiliary data encoding in a disk drive system
AssigneeCirrus Logic, Inc.
InventorDavid E. Reed
Life of this patent
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Abstract
A disk drive system comprises control circuitry and a disk device. The disk device transfers a read signal representing user data, servo data, and auxiliary data to the control circuitry. The control circuitry detects encoded signals representing “0” and “1” auxiliary data bits from the read signal. The control circuitry decodes the encoded signals into the auxiliary data bits. The encoded signals representing the “0” auxiliary data bits have opposite polarity from the encoded signals representing the “1” auxiliary data bits. Polarity reversal pulses are between consecutive encoded signals with opposite polarities. The auxiliary data bits could be repeatable run-out data that is processed to generate a position signal that the disk device uses to compensate for repeatable run-out error.
Claims32
Disk drive control circuitry comprising:
- detection circuitry configured to detect encoded signals representing “0” and “1” auxiliary data bits in a read signal from a disk device;
- and
- decoding circuitry configured to decode the encoded signals into the auxiliary data bits wherein the encoded signals representing the “0” auxiliary data bits have the opposite polarity from the encoded signals representing the “1” auxiliary data bits and wherein polarity reversal pulses are between consecutive ones of the encoded signals with opposite polarities.
A disk drive system comprising;
- a disk device configured to store user data, servo data, and auxiliary data and to transfer a read signal representing the user data, the servo data, and the auxiliary data;
- and
- control circuitry configured to detect encoded signals representing “0” and “1” auxiliary data bits from the read signal and to decode the encoded signals into the auxiliary data bits, wherein the encoded signals representing the “0” auxiliary data bits have opposite polarity from the encoded signals representing the “1” auxiliary data bits, and wherein polarity reversal pulses are between consecutive ones of the encoded signals with opposite polarities.
A method for operating disk drive control circuitry, the method comprising:
- detecting encoded signals representing “0” and “1” auxiliary data bits in a read signal from a disk device;
- and
- decoding the encoded signals into the auxiliary data bits wherein the encoded signals representing the “0” auxiliary data bits have the opposite polarity from the encoded signals representing the “1” auxiliary data bits and wherein polarity reversal pulses are between consecutive ones of the encoded signals with opposite polarities.
A method for operating a disk drive system, the method comprising;
- transferring a read signal representing user data, servo data, and auxiliary data from a disk device to control circuitry;
- in the control circuitry, detecting encoded signals representing “0” and “1” auxiliary data bits from the read signal;
- and
- in the control circuitry, decoding the encoded signals into the auxiliary data bits, wherein the encoded signals representing the “0” auxiliary data bits have opposite polarity from the encoded signals representing the “1” auxiliary data bits, and wherein polarity reversal pulses are between consecutive ones of the encoded signals with opposite polarities.
A read channel comprising:
- a sampling circuit configured to receive and sample a read signal from a disk device to generate samples;
- an adaptive filter configured to shape the samples to produce an equalized signal;
- a detector configured to detect encoded signals in the equalized signal;
- and
- a decoder configured to decode the encoded signals into user data, servo data, and auxiliary data wherein the encoded signals representing “0” auxiliary data bits have the opposite polarity from the encoded signals representing “1” auxiliary data bits and wherein polarity reversal pulses are between consecutive ones of the encoded signals with opposite polarities.
Dependencies are inferred from the claim text.