摘要:
A disk drive is disclosed comprising a disk comprising a plurality of servo tracks defined by servo sectors. The disk drive further comprises a head comprising a read element offset linearly from a write element by a gap such that when the disk rotates, the read element reaches a servo sector before the write element. During a first operation, a first length of a beginning of the servo sector is read, and during a write operation, a second length of the beginning of the servo sector shorter than the first length is read to enable data to be written while the read element is over at least part of the servo sector.
摘要:
A disk drive is disclosed comprising a disk comprising a plurality of servo tracks defined by servo sectors, and a head actuated over the disk, wherein the head comprises a read element operable to generate a read signal. The disk drive further comprises a fly height sensor operable to generate a fly height signal for the head, and control circuitry comprising a multiplexer operable to multiplex the read signal and the fly height signal to a transmission line. The multiplexer is configured to select the read signal when reading the servo sectors of a servo track, and configured to select the fly height signal when reading a segment of the servo track between consecutive servo sectors.
摘要:
A disk drive is disclosed comprising a disk having a plurality of data tracks, wherein each data track comprises a plurality of data sectors. A head is actuated radially over the disk in order to read one of the data sectors from a target data track on the disk. The data sector is stored in a buffer and decoded with an error correction code (ECC) decoder. When the decode fails, an erasure window is adjusted based on a number of non-read data sectors recorded in the target data track, wherein the erasure window comprises a length spanning at least one ECC symbol in the data sector. The data sector is read from the buffer and decoded with the ECC decoder using the erasure window.
摘要:
A method is disclosed for performing a defect scan for a disk drive. Data is recorded on a first data area of a disk substantially free from defects and on a second data area of the disk substantially affected by at least one defect. A defect scan parameter is initialized with an initial setting. The first data area is read to determine a first defect threshold, and the second data area is read to determine a second defect threshold. A margin is saved representing a difference between the first and second defect thresholds. The setting for the defect scan parameter is adjusted, and the elements of reading the first and second data areas and saving a corresponding margin are repeated at least once. A setting is then selected for the defect scan parameter in response to the saved margins.
摘要:
A disk drive is disclosed comprising a disk and a head actuated radially over the disk. The head is positioned over a first radial location, and a first data tracks per inch (TPI—1) is selected for data tracks recorded near the first radial location. The head is positioned over a second radial location, and a second data tracks per inch (TPI—2) is selected for data tracks recorded near the second radial location. The head is positioned over a third radial location, and a third data tracks per inch (TPI—3) is selected for data tracks recorded near the third radial location. A geometry of the head is estimated in response to TPI—1, TPI—2 and TPI—3.
摘要:
Disclosed is a disk drive having a disk, a masked read-only memory (ROM) device, a reprogrammable nonvolatile memory device, and a microprocessor for executing program code. The disk has a magnetic data storage surface with embedded servo wedges for defining data storage tracks including reserve tracks. The masked ROM device stores program code for implementing a spindle motor controller, program code for implementing a portion of a servo controller for track following along a data storage track, and program code for implementing a portion of a disk controller for controlling writing disk data to and reading disk data from the reserve tracks. The reprogrammable nonvolatile memory device stores data parameters relating to the disk drive's configuration. The reserve tracks store program code for implementing a cache control system for controlling caching of disk data in a cache memory.
摘要:
A disk drive is disclosed comprising a disk, a head for writing data to the disk, and control circuitry coupled to the head. The control circuitry is operable to write data to the plurality of data tracks, read a first data area of a first data track to generate a first read back signal, determine a first quality metric and a channel flag in response to the first read back signal, determine that the first quality metric exceeds a first threshold, apply additional stress to the first data area, reread the first data area to generate a second read back signal, determine a second quality metric in response to the second read back signal, and determine whether the second quality metric exceeds a second threshold.