Abstract: A defect scan method is carried out to detect a defective portion in a storage medium of a storage device, the storage medium including multiple storage regions including a first storage region and a second storage region. The defect scan method includes scanning a part of the storage regions of the storage medium to detect a defective portion therein, before the storage device is connected to a host, a scanned storage region including the first storage region and a non-scanned storage region including the second storage region, mapping logical addresses to physical addresses of a non-defective portion of the first storage region, scanning the second storage region to detect a defective portion therein, after the storage device is connected to the host, and mapping logical addresses to physical addresses of a non-defective portion of the second storage region.

Abstract: A defect scan method is carried out to detect a defective portion in a storage medium of a storage device, the storage medium including multiple storage regions including a first storage region and a second storage region. The defect scan method includes scanning a part of the storage regions of the storage medium to detect a defective portion therein, before the storage device is connected to a host, a scanned storage region including the first storage region and a non-scanned storage region including the second storage region, mapping logical addresses to physical addresses of a non-defective portion of the first storage region, scanning the second storage region to detect a defective portion therein, after the storage device is connected to the host, and mapping logical addresses to physical addresses of a non-defective portion of the second storage region.

Abstract: A defect scan method is carried out to detect a defective portion in a storage medium of a storage device, the storage medium including multiple storage regions including a first storage region and a second storage region. The defect scan method includes scanning a part of the storage regions of the storage medium to detect a defective portion therein, before the storage device is connected to a host, a scanned storage region including the first storage region and a non-scanned storage region including the second storage region, mapping logical addresses to physical addresses of a non-defective portion of the first storage region, scanning the second storage region to detect a defective portion therein, after the storage device is connected to the host, and mapping logical addresses to physical addresses of a non-defective portion of the second storage region.

Abstract: A magnetic disk device according to an embodiment is provided with a magnetic disk including a recording surface with a plurality of tracks on which data is recorded, a head configured to write the data to the recording surface, and a controller configured to count a write count corresponding to a number of writes by the head, and to perform data refresh when the write count exceeds a threshold. While counting the write count, the controller counts using a first count-up value when the head performs an on-track write, and counts using a second count-up value higher than the first count-up value when the head performs an off-track write.

Abstract: An HDD, in which a magnetic head is moved in a substantially radial direction of a rotating magnetic disk to record and reproduce data on and from the disk, has an FPC that has a head IC. The FPC has a board and a flexible cable. The board has three chip resistors and a connector pin. The head IC is mounted on the distal end of the flexible cable. To identify the head IC, a probe of an inspection apparatus is connected to the connector pin, thereby to measure the impedance of the chip resistors.

Abstract: A read/write circuit detects the occurrence of a thermal asperity in accordance with data read from a disk. Thermal asperity status register sets a flag corresponding to thermal asperity occurrence spot in a servo area. A write/read fault generator outputs no WRF signals if the corresponding flag of the thermal asperity status register is set even when error detection is notified from an address error register, and thereby enables a sequencer to continue its recording and reproducing operation.

Abstract: A table containing a servo sector number of the servo sector which includes the data sector, and the ordinal of the data sector at which the data sector is disposed in the servo sector is used to locate a data sector. A control firmware is used to obtain, from the table, the servo sector number of the servo sector including a target data sector and the target data sector number indicating the ordinal at which the target data sector is disposed in the target data sector. The parameters are respectively set in the target servo data sector number register and the target data sector number register. The servo sector number read from servo information previously recorded on the disk is set in the detected servo sector number register. The target servo sector number is compared with the detected servo sector number. If these numbers are equal to each other, the counter is enabled and counts up data sector pulses.

Abstract: In a servo system for a hard disk drive, an integrating circuit for eliminating an offset of a head has its capacitor charged to an extent corresponding to an offset amount, at a time of a track following control operation, before an integral action is done. The integrating circuit performs the integral action through the utilization of the charged capacity to eliminate the offset amount of the head. A CPU retrieves an initially prepared offset table for one of voltage level data corresponding to the offset amount which is determined in accordance with a head's destination track. A D/A converter converts the voltage level data which comes from CPU to a voltage and supplies it to the capacitor in the integrating circuit.