Seagate Technology Incorporated

Mark David Hertz

Edwin Scott Olds

Kenny Troy Coker

Stephen R Cornaby

Hieu Van Nguyen

Travis D Fox

Robert D Cronch

Jack Allen Mobley

Philip E Cloud

A unique system and method for ordering commands may reduce disc access latency while giving preference to pending commands. The method and system involves giving preference to pending commands in a set of priority queues. The method and system involve identifying a pending command and processing other non-pending commands in route to the pending command if performance will not be penalized in doing so. The method and system include a list of command node references referring to a list of sorted command nodes that are to be scheduled for processing.

Prioritizing commands in a data storage device

Method and apparatus for transferring data between a host device and a data storage device having a first memory space and a second memory space. The host issues access commands to store and retrieve data. The device stores commands in the first memory space pending transfer to the second memory space. An interface circuit evaluates relative proximity of first and second sets of LBAs associated with pending first and second commands, and delays promotion of later pending commands in front of earlier pending commands during an overlap condition. If the overlap is caused by performance enhancing features (PEF) the PEFs are disabled so the commands can be scheduled for disc access. Indicators are set in the commands to signal that a PEF has caused the overlap and that PEF can be disabled. Values are added to indicators in the commands such that the PEFs can be modified and avoid overlaps.

Reducing delay of command completion due to overlap condition

A unique system and method for ordering commands to reduce disc access latency while giving preference to pending commands. The method and system involves giving preference to pending commands in a set of priority queues. The method and system involve identifying a pending command and processing other non-pending commands in route to the pending command if performance will not be penalized in doing so. The method and system include a list of command node references referring to a list of sorted command nodes that are to be scheduled for processing.

Method and apparatus for transferring data between a host device and a data storage device having a first memory space and a second memory space. The host issues access commands to store and retrieve data. The device stores write data associated with write commands in the first memory space pending transfer to the second memory space. An interface circuit evaluates relative proximity of first and second sets of LBAs associated with pending first and second write commands, and forms an adaptive bi-directional write skip mask when the sets of LBAs fit within a predetermined mask interval. The mask is preferably slidably adjustable to encompass both sets of LBAs and is preferably expandable to accommodate additional sets of LBAs. The data within the mask are treated as a combined write command and are thereafter written in an order corresponding to an order in which the data appear in the mask.

Adaptive bi-directional write skip masks in a data storage device

Window center settings in a read channel of a magnetic disk drive are controlled. The magnetic disk drive is suitable for reading data from a magnetic disk. A number of read operations are performed and data is read from the magnetic disk. Read errors are detected during the read operations. The number of read errors is recorded and error types are determined. Adjustment of the window center settings is controlled based on the number of read errors detected and the error types determined.

Growing community of inventors

Oklahoma City, OK, United States of America

Mark David Hertz