Seagate Technology Incorporated

Western Digital Technologies, Inc.

Travis D Fox

Edwin Scott Olds

Mark A Thiessen

Wayne Howard Vinson

Stephen R Cornaby

Mark A Gaertner

Shane G Nowell

Mark Alan Heath

Abbas Ali

Danny J Kastler

Mark David Hertz

Philip E Cloud

Raymond L Willis

Upon a first transition from a first state to a second state, a first bit in a memory unit comprising a plurality of bits is programmed. Upon a first transition from the second state to the first state, a second bit in the memory unit is programmed, the second bit being before the first bit in the sequence of the plurality of bits. Upon a second transition from the first state to the second state, a third bit in the memory unit is programmed, the third bit being subsequent to the first bit by at least two bits in the sequence of the plurality of bits. Upon a second transition from the second state to the first state, a fourth bit in the memory unit is programmed, the fourth bit being before the third bit in the sequence of the plurality of bits.

Data storage device state detection on power loss

Embodiments described herein relate to systems and methods for decreasing power consumption of a storage device. More specifically, embodiments disclosed herein are directed to reducing power consumption of a data storage device by enabling a command buffer associated with the data storage device to store received commands without executing the commands until a predetermined number of commands have been stored in the buffer.

Power aware power safe write buffer

A target location for an actuator of a disk drive is determined for prepositioning the actuator before receiving a command from a host. The target location is determined based on at least one of a characteristic of the disk drive, recent command activity of the host, and information provided by the host. The actuator is moved toward the target location to preposition the actuator.

Actuator prepositioning for disk drive

A method for determining an aging period for retaining a write-back data in a cache memory prior to writing the write-back data to a storage media is determined through use of a write-back aging routine. The aging period is based on a proportional utilization level of the cache memory by the write-back data, the higher the memory utilization level, the shorter the period for aging the write-back data. The aging period takes a form of an aging threshold, which differs depending on the memory utilization level, i.e., the amount of cache memory utilized by the write-back data. The method includes, identifying the memory utilization level, selecting the data aging threshold based on the memory utilization level; and writing the data from the cache memory to the storage media when an age of the data in the memory exceeds the selected data aging threshold.

Adaptive resource controlled write-back aging for a data storage device

A method for improving throughput performance of a data storage device by executing an execution critical write-back data priority routine programmed into a controller of the data storage device. The method includes, determining a write-back data aging threshold limit; identifying and executing a pending command; recognizing write-back data exceeding the aging threshold limit as an ending position aged data execution command; determining a read/write head following an execution of a pending command; determining a latency portion of the aged data execution command based on the determined head position; ascertaining a total execution time for each of a plurality of commands based on the determined head position; selecting from the plurality of commands an additional command executable within the determined latency portion; and executing both the additional command and the aged data execution command following execution of the pending command, when the total execution time of the aged data execution command is unaffected.

Method for improving data throughput for a data storage device

Method and apparatus for transferring speculative data in lieu of requested data in a data transfer operation. First data are transferred in response to an execution of a first pending command. Speculative data are transferred instead of second data associated with a second pending command during a next available latency period for the second data, preferably when the speculative data are adjudged as having a utility greater than a utility of the second data. The first and second commands are preferably received in a queue and a command execution algorithm identifies the second command as a next best command to be executed after execution of the first command. The above steps are preferably carried out by a controller of a data storage device.

Transferring speculative data in lieu of requested data in a data transfer operation

A data storage device with a cache memory in communication with a control processor programmed with a routine to effect data throughput with a host device. The data storage device includes a head-disc assembly responsive to the control processor retrieving a host data along with a speculative data in a form of a read data. The control processor adjusting a range for acquisition of the speculative data based on data stored in cache memory fragments of the cache memory. The cache memory storing the read data in an unused cache memory fragment, while the control processor updates a history queue and a band count table based on the acquired read data and releases an oldest cache memory fragment with a lowest count value in the band count table from the cache memory in response to a need for cache memory space.

Band detection and performance optimization for a data storage device

Apparatus and method for transferring data between a disc drive data storage device and a host device. Access commands are provided by the host device to the data storage device to read and write data. Write caching is employed so that the write data are temporarily stored in a buffer. A phase time (access time) is determined for each pending access command, and the access commands are executed in relation to the identified phase times. However, when the total amount of accumulated write data in the buffer exceeds a first threshold, a thread of write commands having an intermediary phase time less than a selected duration is selected and written in lieu of other pending access commands. When the total amount of accumulated write data exceeds a second threshold, as many write commands are serviced as possible during a preselected purge time.

Optimizing data transfer performance through partial write command purging in a disc drive

A disc drive includes a base and a disc rotatably attached to the base. The disc drive also includes an actuator assembly rotatably attached to the base and a device for moving the actuator assembly. The actuator assembly includes an arm carrying a transducer head in a transducing relationship with respect to the disc. The disc drive further includes a servo circuitry and a controller for controlling movement of the actuator assembly during a track follow and a track seek. Piezoelectric transducers are attached to the actuator assembly for non-intrusive measurement of stiction and friction forces developed between the transducer head and the disc during a disc drive spin-up.

Disc drive stiction/friction characterization utilizing piezoelectric microactuators

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

Method and apparatus for improving data transfer rate performance of a disc drive configured to store data from a host device in physical data blocks identified by the host device in terms of logical block addresses (LBAs). A sequence of input/output (I/O) commands is provided to the disc drive each directing the transfer of data between at least one LBA within the disc drive and the host device. The correlation between the time sequence of the I/O commands to the locations of the physical data blocks corresponding to the LBAs accessed by the I/O commands is obtained, and preferably displayed graphically in a three-dimensional histogram showing physical data block accesses by time and by frequency. At least one data transfer parameter of the disc drive is thereafter adjusted in relation to the physical operations of the drive in response to the I/O command sequence.

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Edmond, OK, United States of America

Travis D Fox