Abstract: 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.

Abstract: 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.

Abstract: A data storage device with a cache memory in communication with a control processor programmed with a data retention prioritization routine to effect data throughput with a host device. The data storage device includes an apparatus responsive to the control processor retrieving host data along with speculative data. The cache memory storing the host data in addition to the speculative data, wherein the speculative data includes both read on arrival data and read look ahead data. The control processor executing the data prioritization routine to prioritize removal of the host data from the cache memory prior to removal of the read on arrival data while maintaining persistence of the read look ahead data in the cache memory subsequent to removal of the read on arrival data.

Abstract: 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.

Abstract: 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 bidirectional 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.

Abstract: 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.