Abstract: In some examples, a method includes assigning, to each respective task queue of a plurality of task queues, a respective priority ratio based at least in part on a number of tasks in the respective task queue. The method further includes assigning, by a processor of a plurality of processors, respective tasks from the respective task queues to at least one processor of the plurality of processors in an order based at least in part on the respective priority ratio, wherein the respective priority ratio defines a relative frequency with which tasks from the respective task queue are assigned to the at leak one processor.

Abstract: In some examples, a method includes assigning, to each respective task queue of a plurality of task queues, a respective priority ratio based at least in part on a number of tasks in the respective task queue. The method further includes assigning, by a processor of a plurality of processors, respective tasks from the respective task queues to at least one processor of the plurality of processors in an order based at least in part on the respective priority ratio, wherein the respective priority ratio defines a relative frequency with which tasks from the respective task queue are assigned to the at leak one processor.

Abstract: In general, techniques are described for performing hardware-based queue automation for hardware engines. An apparatus comprising a hardware engine and a hardware event queue manager may be configured to perform the techniques. The hardware event queue manager may be configured to receive, from a processing unit separate from the hardware event queue manager, an event to be processed by the hardware engine, and perform queue management with respect to an event queue to schedule processing of the event by the hardware engine.

Abstract: A hard disk drive that includes a disk with data written onto a plurality of tracks, a spindle motor that rotates the disk, and a head that is coupled to the disk. The disk drive also includes a circuit that writes data onto a first writable shingle band of tracks if the first writable shingle band is adjacent to a guard band of tracks. The first writable shingle band includes a number of tracks that is a function of a head width. The guard band of tracks is capable of becoming a writable shingle band. Changing the designation of a shingle band between guard and writable creates floating guard bands. The creation of floating guard bands allows for the writing of a single band without having to move and restore adjacent tracks until reaching a fixed guard band as required in the prior art.

Abstract: A hard disk drive that includes a disk with data written onto a plurality of tracks, a spindle motor that rotates the disk, and a head that is coupled to the disk. The disk drive also includes a circuit that writes data onto a first writable shingle band of tracks if the first writable shingle band is adjacent to a guard band of tracks. The first writable shingle band includes a number of tracks that is a function of a head width. The guard band of tracks is capable of becoming a writable shingle band. Changing the designation of a shingle band between guard and writable creates floating guard bands. The creation of floating guard bands allows for the writing of a single band without having to move and restore adjacent tracks until reaching a fixed guard band as required in the prior art.

Abstract: A disk drive apparatus is shown that provides multi-tasking of firmware and hardware separately. A shared data structure is shown that permits queuing of multiple task requests and storing of multiple task results for later use, decreasing a need for wait time between components such as disk drive firmware and hardware. Further efficiencies are provided, including power saving modes when higher power disk drive components are not in use.

Abstract: According to one embodiment, a disk drive apparatus includes a defect table formed using more than one defect detection standard. Methods and devices are described using different defect detection standards to detect and map defects of different sizes and in specific regions that can affect drive operation. Also, methods and devices are described that provide fast and efficient defect scanning in selected regions due to utilization of error correction systems. Methods are shown where during defect detection a read/write gate assertion is triggered using a servo gate pulse.

Abstract: A disk drive includes a disk for storing information representing data, and a memory device. A method for writing includes locating a first data sector on a disk where a write operation fails, identifying the first data sector and a plurality of other data sectors near the first data sector as a grown defect, and storing the location of the first data sector and the plurality of other data sectors on a grown defect list. The memory device includes a list of grown defects that identifies a plurality of data sectors stored along a track between the first servo wedge and the second servo wedge on a selected track as data sectors which may not be written to.

Abstract: In the disk controller in a hard disk system, the microcontroller is an integral part of the servo positioning system. The servo positioning system is the system responsible for positioning the read/write heads. This involves moving the read/write heads from track to track and holding the head in place as data is read or written. A time and calculation intensive portion of the control algorithm is the calculation of the position error signal, which represents the degree to which the actual position of the head varies from the desired position. A hardware position error signal circuit is provided to calculate this signal, thus freeing microprocessor bandwidth for other tasks and facilitating a more stable controller. Furthermore, a circuit for adjusting erroneous cylinder numbers is provided.