Magnetic disk apparatus, read gate optimization method and program
AssigneeFujitsu Limited
InventorYuichiro Yamazaki
Life of this patent
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Abstract
A hard disk controller generates a read gate signal RG which has a predefined read start time and read end time set based on a sector pulse as a reference. A read data demodulation unit reproduces read data from a readout signal of medium by executing a read based on the read gate signal RG. A read gate optimization unit detects errors of read data demodulated by the data demodulation unit while varying the read start time and the read end time of the read gate signal RG, determines the read start time and the read end time at which the detected errors will be minimized and sets these in the read gate generation unit.
Claims18
A magnetic disk apparatus including:
- a read gate generation unit which generates a read gate signal having a predefined read start time and read end time that are set using a sector pulse as a reference;
- and
- a data demodulation unit which reproduces read data from a medium readout signal by executing a read based on the read gate signal,
- the magnetic disk apparatus comprising:
- a read gate optimization unit which detects errors of read data demodulated by the data demodulation unit while varying the read start time and the read end time of the read gate signal, the read gate optimization unit determining the read start time and the read end time at which the detected errors are minimized and setting the determined read start and end times in the read gate generation unit;
- and
- wherein the read gate optimization unit includes:
- a timing adjustment unit which varies the read start time and the read end time of the read gate signal for output to the data demodulation unit, for each of plural times of executions of test read;
- an error detection unit which detects errors of the read data demodulated by the data demodulation unit, for each execution of test read, based on the read gate signal output from the timing adjustment unit;
- and
- an optimum time determination unit which determines as optimum times the read start time and the read end time of the read gate signal at which the errors are minimized of a plurality of errors detected by the error detection unit, the optimum time determination unit setting the determined optimum times in the read gate generation unit.
A read gate optimization method for a magnetic disk apparatus including a read gate generation unit which generates a read gate signal having a predefined read start time and read end time that are set using a sector pulse as a reference, and a data demodulation unit which reproduces read data from a medium readout signal by executing a read based on the read gate signal, the method comprising:
- a timing adjustment step varying the read start time and the read end time of the read gate signal for output to the data demodulation unit, for each of plural times of executions of test read;
- an error detection step detecting errors of the read data d modulated in the data demodulation unit, for each execution of test read, based on the read gate signal output in the timing adjustment step;
- and
- an optimum time determination step determining as optimum times the read start time and the read end time of the read gate signal at which the errors are minimized of a plurality of errors detected in the error detection step, and setting the determined optimum times in the read gate generation unit.
A program embodied in a computer readable medium to cause a computer, the computer being incorporated in a magnetic disk apparatus including a read gate generation unit which generates a read gate signal having a predefined read start time and read end time that are set using a sector pulse as a reference, and a data demodulation unit which reproduces read data from a medium readout signal by executing a read based on the read gate signal, to execute the steps of:
- a timing adjustment step varying the read start time and the read end time of the read gate signal for output to the data demodulation unit, for each of plural times of executions of test read;
- an error detection step detecting errors of the read data demodulated in the data demodulation unit, for each execution of test read, based on the read gate signal output in the timing adjustment step;
- and
- an optimum time determination step determining as optimum times the read start time and the read end time of the read gate signal at which the errors are minimized of a plurality of errors detected in the error detection step, and setting the determined optimum times in the read gate generation unit.
Dependencies are inferred from the claim text.