Storage device
View Patent ↗A magnetic disk device includes a head that reads position information, a position-information correction value for correcting the position information, and an error correcting code for the position-information correction value from a storage medium; a microcontroller unit (MCU) and an error check and correct (ECC) circuit for correcting an error in the position-information correction value based on the error correcting code; and a static var compensator (SVC) that performs position control based on either one of the position-information correction value read by the head and the position-information correction value with the error corrected by the MCU and the ECC circuit, and the position information read by the head so that the head is located at a target position on the storage medium.
1. A storage device comprising:
a head that reads position information, a position-information correction value for correcting the position information, and an error correcting code for the position-information correction value from a storage medium;
an error correcting unit that corrects an error in the position-information correction value using the error correcting code; and
a control unit that performs position control based on either one of the position-information correction value read by the head and the position-information correction value with the error corrected by the error correcting unit, and the position information read by the head so that the head is located at a target position on the storage medium, wherein
when the error in the position-information correction value read by the head cannot be corrected, the error correcting unit causes a storage unit to store information that prevents the position-information correction value from being used for position control.
2. The storage device according to claim 1 , wherein
the head reads from the storage medium a parity bit for detecting an error in the position information, and
the error correcting unit determines based on the error correcting code and the parity bit whether the position-information correction value read by the head has an error.
3. The storage device according to claim 1 , wherein
the error correcting code is generated for each combination of a plurality of position-information correction values.
4. The storage device according to claim 1 , wherein
the error correcting unit uses a Hamming-distance detection circuit to determine whether the position-information correction value read by the head has an error.