摘要:
Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is discussed that includes: an equalizer circuit, a signal to noise ratio calculation circuit, and a parameter adjustment circuit. The equalizer circuit is operable to equalize a data input to yield an equalized output. The signal to noise ratio calculation circuit is operable to calculate a signal to noise ratio of the equalized output based at least in part on a noise power derived from the equalized output. The parameter adjustment circuit is operable to adjust a parameter based at least in part on the signal to noise ratio.
摘要:
Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is discussed that includes: an equalizer circuit, a signal to noise ratio calculation circuit, and a parameter adjustment circuit. The equalizer circuit is operable to equalize a data input to yield an equalized output. The signal to noise ratio calculation circuit is operable to calculate a signal to noise ratio of the equalized output based at least in part on a noise power derived from the equalized output. The parameter adjustment circuit is operable to adjust a parameter based at least in part on the signal to noise ratio.
摘要:
A self-servo-write system including a timing control module and a position control module. The timing control module is configured to generate (i) timing information of a first set of servo spirals and (ii) timing control signals for writing a second set of final servo wedges based on the timing information. The position control module is configured to generate (i) position information of the first set of servo spirals and (ii) positioning control signals for writing the second set of final servo wedges based on the timing information. Less than half of the servo spirals in the first set of servo spirals are over-written while writing the second set of final servo wedges. A ratio of a first number of final servo wedges in the second set of final servo wedges to a second number of servo spirals in the first set of servo spirals is a non-integer greater than one.
摘要:
Harmonic selection for track following is described for a hard disk drive comprising at least one magnetic disk capable of storing data and spinning, a controller capable of controlling a read/write head capable of reading and writing data while following a track on a surface of the at least one magnetic disk, and a memory device capable of storing data relating to the operation of the hard disk drive. A drive function test on the hard disk drive is performed, during which harmonic frequencies are identified which cause disturbances for the hard disk drive. Data regarding the harmonic frequencies which cause the greatest disturbances for the hard disk drive is stored in the memory device. The data regarding the harmonic frequencies which cause the greatest disturbances is forwarded to the controller upon the at least one magnetic disk spinning.
摘要:
A data storage system includes a storage medium having a plurality of data sectors and a head that communicates with the data storage medium. The head produces a readback signal when reading information from the data storage medium. A computation unit extracts a distortion component of the readback signal and generates a position error signal from the distortion component.
摘要:
A disk drive is disclosed comprising a disk, a head, and an actuator for actuating the head over the disk. The disk drive further comprises a state variable memory for storing a plurality of state variable sets, wherein each state variable set comprises a plurality of state variables and each state variable set corresponds to a task object. A coefficient memory for stores a plurality of coefficient sets, wherein each coefficient set comprises a plurality of coefficients and each coefficient set corresponds to a task object. A task object is executed by initializing a base state register to address a selected one of the state variable sets in the state variable memory, and initializing a base coefficient register to address a selected one of the coefficient sets in the coefficient memory.
摘要:
A disk drive controller including a differential voice coil motor control function is disclosed. The differential voice coil motor control function includes an on-chip compensation network for the inner control loop, including a resistor formed of one or more MOS transistors connected in series. The gate of the MOS transistors in the compensation network is driven with a bias voltage based on a tuning current, where the tuning current is derived so that it varies with process and temperature variations of the integrated circuit, for example with variations in an on-chip capacitor. The on-chip compensation network can be tuned with sufficient precision to properly compensate the inner control loop to provide the desired frequency response in driving the voice coil motor in the disk drive.
摘要:
A terminal voltage of an actuator motor is measured while the actuator motor is in a high impedance state. An internal voltage of the actuator motor is measured, and a back-EMF voltage of the actuator motor is estimated in response to the terminal voltage of the actuator motor and the internal voltage of the actuator motor. A drive current supplied to the actuator motor is controlled in response to the estimated back-EMF.
摘要:
A disk drive controller including a differential voice coil motor control function is disclosed. The differential voice coil motor control function includes an on-chip compensation network for the inner control loop, including a resistor formed of one or more MOS transistors connected in series. The gate of the MOS transistors in the compensation network is driven with a bias voltage based on a tuning current, where the tuning current is derived so that it varies with process and temperature variations of the integrated circuit, for example with variations in an on-chip capacitor. The on-chip compensation network can be tuned with sufficient precision to properly compensate the inner control loop to provide the desired frequency response in driving the voice coil motor in the disk drive.
摘要:
A probe position error detecting method and apparatus in a probe-based data storage system are provided. The method includes preparing servo codes, which are Gray codes. The Gray codes have a Hamming distance of 1 and satisfy alternate conditions for Q (a natural number) and Q+1, the conditions being based on the numbers of “1” bits of codewords of the Gray codes. The method further includes detecting a probe position error from a signal read by a servo probe when the servo probe consecutively scans “1” bits of codewords of the servo codes when tracking. The apparatus includes: a plurality of servo probes; a tracking condition checker; a plurality of position error detectors that correspond to the plurality of servo probes, respectively; and an average position error calculator. Probe position errors are be detected with a stable noise characteristic using fewer probes.