Seagate Technology Incorporated

Timothy Ted Walker

Robert Matousek

Karl Louis Enarson

Anish A Ukani

Matthew Chad Burton

Ronald D Metzner

Mark A Gaertner

Jon David Trantham

Steven Scott Williams

John Edward Moon

Jason Matthew Feist

Jason Dale Gregg

Paul Francis Kusbel

David R Street

Hemant Vitthalrao Mane

Shawn Alan Wakefield

Phillip Raymond Colline

John M Baker

Chiaming Yang

Bryan David Wyatt

Christopher Anthony Markey

Daniel Thomas Kiser

Apparatus and method for executing controller memory buffer (CMB) based data transfer commands in a distributed data processing environment. In some embodiments, a storage device having a device controller and a main non-volatile memory (NVM) is coupled to a client device via an interface. The client device respectively issues normal data transfer commands and bypass data transfer commands to the storage device. The normal data transfer commands include read and write commands that result in transfer of data between the NVM and the client device using a normal data path through the storage device. The bypass data transfer commands involve an allocated CMB of the storage device directly controlled and accessed by the client device. In this way, write data are directly placed into the CMB for writing to the NVM, and readback data from the NVM are directly recovered from the CMB by the client device.

Secure command memory buffer transfers in a low trust environment

An application programming interface (API) that enables installation of an application as one or more key-value objects on a data storage drive such as a hard disk drive, a solid state drive or a hybrid drive. The API also enables execution of the application within a controlled environment of the data storage drive.

Active drive API

A programmable controller and method for correcting operation of a read/write head in a disc drive having an embedded servo system in which the head is not reading correctly operates by applying a write current to the failed head only after the head is positioned over an area of a disc that does not have useful data thereon. Movement and position of the head that is not reading correctly is determined from a signal from an adjacent head. The adjacent head is used to read servo information. After the adjacent head has provided servo information and the controller repositions the adjacent head in a safe area, a write current is applied to the failed head to realign the head without the potential of adversely impacting data stored in adjacent tracks.

Apparatus and method for wiggle recovery in a disc drive having an embedded servo

The present invention uses temperature readings obtained aperiodically, on demand. Rather than merely obtaining temperature readings on each expiration of a fixed timer, operating parameters are updated in response to a fault detected in the data path. Data handling systems of the present invention each include at least one data path having a thermal range within which it operates best. Applicant notes that some &ldquo;key&rdquo; operating parameters typically have a substantial effect on this thermal range. Temperature sensors positioned near the transducers provide a temperature reading to control circuits, which update &ldquo;key&rdquo; operating parameter values in response to indications of faults in a primary data path. This reduces the need for more frequent temperature monitoring and calculation-intensive recalibration.

Thermally compensated data handling system using aperiodic temperature readings

Apparatus and method for a head switching operation utilizing an automatic dummy load in a disc drive. A preamplifier circuit sequentially selects head positions and applies corresponding bias currents. A sequence control circuit automatically diverts the path of a first bias current from a head selection circuit to a dummy load after detecting an input of a second head location value into a buffer, and before the input is complete. After a bias current value for the second head is written into the buffer, the sequence control automatically deasserts the path to the dummy load after a predetermined time interval. The second bias current is then applied to the second head.

Head switching operation utilizing an automatic dummy load

An apparatus and method for determining the configuration of a disc drive head-disc assembly (HDA). The HDA includes an array of rotatable discs and an actuator adjacent the discs, with the actuator supporting a maximum number of heads in a fully populated configuration and a reduced number of heads in a depopulated configuration. Each head is disposed at a unique head position. During each spin-up of the disc drive, a servo circuit determines an impedance of a selected head position having a head when the disc drive is fully populated, but not when the disc drive is depopulated. The servo circuit identifies this configuration of the HDA in relation to the determined impedance, and initializes the drive accordingly. The drive then identifies the configuration of the HDA based on the value of the impedance, initializing the drive accordingly.

Reduced head population detection in a disc drive

An apparatus and method for determining the configuration of a disc drive head-disc assembly (HDA). The HDA includes an array of rotatable discs and an actuator adjacent the discs, with the actuator supporting a maximum number of heads in a fully populated configuration and a reduced number of heads in a depopulated configuration. Each head is disposed at a unique head position. A servo circuit determines an impedance of a selected head position having a head when the disc drive is fully populated but not when the disc drive is depopulated. The servo circuit identifies this configuration of the HDA in relation to the determined impedance, and initializes the drive accordingly.

A method and apparatus are disclosed for optimizing operational performance of a disc drive. The disc drive is provided with an integrated temperature measurement circuit which provides a temperature measurement signal indicative of operational temperature of the disc drive. The integrated temperature measurement circuit is formed as part of an application specific integrated circuit (ASIC) housing additional circuitry used by the disc drive during operation. A parametric configuration circuit, operably coupled to the integrated temperature measurement circuit, identifies selected parameters for use by the disc drive to optimize disc drive performance, the parameters arranged as a plurality of parameter sets corresponding to a plurality of predefined operational temperature ranges. The parametric configuration circuit periodically measures the operational temperature of the disc drive through evaluation of the temperature measurement signal, identifies the operational temperature range in which the measured operational temperature falls, and implements the parameter set corresponding to the identified operational temperature range.

Integrated temperature sense circuit in a disc drive

A method and apparatus are disclosed for optimizing operational performance of a disc drive through temperature dependent parametric configuration. A plurality of parameter sets corresponding to a plurality of predefined contiguous operational temperature ranges of the disc drive are initially established. During operation of the disc drive, a temperature sensor is used to periodically measure the temperature of the drive. The operational temperature range in which the measured temperature falls is identified, and the disc drive utilizes the parameter set corresponding to the identified operational temperature range.

Temperature dependent disc drive parametric configuration

Apparatus and method for detecting servo defects in a disc drive, the servo defects providing false indications of the position of a disc drive head with respect to a selected track. During use of a position error signal (PES) to position the head with respect to the selected track, the PES comprising a sequence of PES samples, the disc drive determines a first difference term as a selected combination of a first set of PES samples. A second, subsequent difference term is also generated as a selected combination of a second set of PES samples, the second set of PES samples including at least one PES sample which does not appear in the first set of PES samples. The magnitudes of the first and second difference terms are compared to a predetermined threshold, and a servo defect is detected at such time that both the first and second difference terms exceed the predetermined threshold and the first difference term exceeds the second difference term. Additionally, at such time that the first difference term exceeds the predetermined threshold and the second, subsequent difference term does not, the disc drive determines whether a servo defect flag has previously been set indicative of the presence of a servo defect, and if the servo defect flag has not been previously set, the drive identifies the presence of a servo defect and sets the servo defect flag.

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Edmond, OK, United States of America

Timothy Ted Walker