Abstract: Method and apparatus for controlling a brushless dc motor, such as the type used in a data storage device to rotate data storage media. A sequence of drive pulses is applied to rotate the motor. The sequence is switched from first to second motor commutation states at a time determined in relation to changes in elapsed time between successive pulses in the sequence. Each drive pulse has a duration established in relation to an inductance of the motor, and is separated from adjacent pulses by an intermediate delay of predetermined value. A peak elapsed time interval between successive pulses is identified, and the next commutation state is switched in at a selected time after the peak time interval. The sequence preferably accelerates the motor from rest to an intermediate velocity, after which back electromotive force (bemf) commutation is used to accelerate the motor to a final operational velocity.

Abstract: The present invention is a system and method for determining clock rate failure in a serial communication interface. A complete clock rate failure can be detected. Alternatively, or in addition, the interface includes a rate matching buffer in which fill characters are added or deleted to accommodate minor clock variations. The number of fill characters added or deleted is monitored to determine whether clock variation is outside of a desired threshold.

Abstract: A method and device are provided that use a sequencer in the device to control interactions on an interface bus. The sequencer is programmed to interrupt a co-processor before execution of a command. Based on the interrupt signal and a stored error mode page, a false error condition is initiated by further programming the sequencer to operate abnormally. After recovery from the error condition, the sequencer is reprogrammed to operate normally.

Abstract: Method and apparatus for initializing a processor based device having a processor that controls an electrical load, such as a motor. The electrical load is initially operationally controlled using startup code executed by the processor. Processor control of the electrical load is next temporarily released so that the electrical load operates in an open control mode while the startup code is displaced with application code during a “brain transplant” operation. Processor operational control of the electrical load is thereafter resumed using the application code and the device is placed in an operational ready mode. The apparatus preferably comprises a data storage device and the electrical load preferably comprises a spindle motor configured to rotate a data storage medium on which the application code is stored, as well as an actuator motor which supports a data transducing head used to access the application code.

Abstract: Post-infection virus protection through data restoration using mirrored data that has been obtained prior to the virus infection. A network appliance in a network mirrors the data of a number of computers in an ongoing manner. An anti-virus module of the network appliance scans data received from a computer to determine whether the computer is infected by a virus. If no virus is identified, the network appliance uses the received data to update a mirrored copy of the computer's data. If, however, the network appliance identifies a virus, the mirrored copy is not updated. Instead, the previous mirrored copy, which represents a pre-infection state of the data, is used to restore the infected computer to its pre-infection state. In this manner, a single copy of an anti-virus utility executed at the network appliance can protect an arbitrary number of computers, which do not require their own anti-virus software.

Abstract: The present invention is directed to a method and apparatus for moving off of a disk drive's crash stop in a consistent manner.

Abstract: A bearing assembly to mount an actuator on a mounting hub of a data storage device comprises a cylindrical hub for the actuator having an internal bore along a cylindrical hub axis. The bearing assembly also has one or more bearings mounted inside the internal bore of the cylindrical hub and a sleeve mounted inside the one or more bearings so that the cylindrical hub rotates relative to the sleeve. The sleeve is adapted to contact a mounting hub. A single piece captive screw is retained within the sleeve and is free to rotate about the cylindrical hub axis independent of the sleeve to engage the mounting hub and tighten the sleeve to the mounting hub.

Abstract: A hard disk drive is disclosed comprising at least one disk rotatable about an axis, an actuator assembly moveable relative to the disk, a transducer positioned on the actuator assembly, an actuator signal line, a piezoelectric actuator element disposed on the actuator assembly and electrically interconnected to the actuator signal line, a processor, a sensor signal line and a piezoelectric sensor element for sensing a vibration. The piezoelectric sensor element is collocated with the piezoelectric actuator element and electrically interconnected to the processor by the sensor signal line. The piezoelectric actuator element is operable to move the at least one transducer relative to a surface of the disk. The piezoelectric sensor element is electrically isolated from the piezoelectric actuator element. A method for detecting a vibration in a hard disk drive actuator assembly is also disclosed.

Abstract: A data storage array is provided such as for a distributed storage system or a consumer electronics device wherein increased data storage capacity is provided at the cost of increased power consumption in relation to industry standard power consumption rates. The array has a plurality of data storage devices, each having an actuator operably disposed in a data storing and retrieving relationship with a data storage medium. The data storage medium is rotated at a speed of substantially greater than 10,000 revolutions per minute, and each of the data storage mediums has a data storage capacity of substantially greater than 100 gigabytes. The increased heat created by the relatively faster rotation speed is handled through improved airflow made possible by a multiple device array constructed in accordance with embodiments of the present invention.

Abstract: Computer networks for brokering the transmission of data between remote computers for purposes of redundancy or collaboration. A service brokers the transfer of data between an initiating computer and a destination device, thereby establishing a peer-to-peer architecture by which data of the initiating computer can be stored remotely on the destination device. The process begins as the initiating computer issues a request for permission to store the data remotely on an identified destination device. The permission is granted if the initiating computer properly identifies the destination device using information, such as a network address or a password, that is privately communicated between the users of the destination device and the initiating computer. Accordingly, substantially any computer user having access to the Internet can achieve remote backup of data and remote collaboration of data with the assistance of a trusted third party who also is registered with the service.

Abstract: Disclosed is a managed reliability storage system and method. A data storage system comprises a plurality of storage devices and at least one storage device controller and may also include additional storage device controllers, one or more host systems, and one or more network connections. Aspects of the invention include reliable data storage formats, planned reliability management, threshold reliability management, and software data recovery. Reliable data formats include fault tolerant storage formats such as RAID and implementations thereof. Planned reliability management includes monitoring of system usage and adjustment of usage reflecting an optimal usage model, scheduled and event driven diagnostic execution and conditional adjustment of operating parameters of storage system components. Software data recovery provides copying and reconstruction of data through redundant data formats including parity, ECC, RLL and others encoding methods.

Abstract: A method of preventing a write operation to a disc in a disc drive during a shock event without the use of a separate shock sensor comprises steps of monitoring an actuator voice coil motor (VCM) control plant output signal, generating an actuator voice coil motor (VCM) plant model module output signal, comparing the VCM plant model module output signal to the VCM control plant module output signal to produce a difference signal, and triggering a write protect gate if the difference signal exceeds a predetermined threshold value.

Abstract: A method and apparatus are provided for performing on-board, in-circuit, and/or wafer level scan-based testing of integrated circuits. With the apparatus and method, one or more sequential storage elements, e.g., flip/flops, are coupled to combinational logic and are configured to have an additional port for receiving a scan mode signal. The scan mode signal sets the sequential storage element into one of two modes of operation: static mode in which the sequential storage element's output does not change on a falling edge of a scan enable signal or a transitional mode in which the sequential storage element's output is permitted to change on the falling edge. With sequential storage elements configured in this manner, a configuration scan is performed to set certain ones of the sequential storage elements into a static mode and other sequential storage elements into a transitional mode. A test pattern is then applied to the sequential storage elements and a pattern capture cycle is commenced.

Abstract: An engagement assembly and associate method are provided for a multiple disc array (MDA) that is receivingly engageable in a data storage array cabinet. The engagement assembly comprises a locking device that is responsive to an MDA position indicator in automatically locking and unlocking the module in the cabinet.

Abstract: An embedded system with reduced susceptibility to single event upset effects. The system includes an instruction memory that can store at least one instruction set. The instruction memory utilizes a parity checking error-detection scheme. The system also includes a non-volatile memory that can store a copy of the at least one instruction set, and a data memory that can store at least one data sequence. The data memory utilizes an error correction coding (ECC) scheme. A controller, which is responsive to the instruction memory, the non-volatile memory, and the data memory, replaces the at least one instruction set in the instruction memory with the copy of the at least one instruction set from the non-volatile memory, if a parity error is detected in connection with the at least one instruction set in the instruction memory. The controller also operates in conjunction with the data memory to implement the ECC scheme.

Abstract: Method and apparatus for assessing a time interval during which a refresh device can be maintained in a self-refresh mode by an associated energy source. The refresh device is initially operated in a self-refresh mode to maintain the device in a selected state. The time interval during which the refresh device can be subsequently maintained in the refresh mode is next determined in relation to an energy requirement value obtained during the self-refresh mode and an energy capacity value from the associated energy source. The energy capacity value is preferably obtained by fully discharging the associated energy source. Preferably, the refresh device is characterized as a dynamic random access memory (DRAM), and the associated energy source is characterized as a rechargeable backup battery. A selected test pattern is preferably written to the refresh device and maintained thereby during the self-refresh mode.

Abstract: According to one embodiment of the present invention, a method of reducing power use in a device capable of operating at two or more power levels includes selecting a range of power management timer settings for a first power management timer. The first power management timer is for switching the device from a first power level to a second power level. In the second power level portions of the device are de-energized. An estimated energy value to complete a series of tasks is calculated for each of a plurality of settings within the range of power management timer settings. A power management timer setting is selected from the range of power management timer settings based on the estimated energy value to complete a series of tasks for each of the plurality of settings within the range of settings.

Abstract: Method arid apparatus for accelerating a multi-phase motor having a rotatable rotor are disclosed. The method incorporates use of a motor control circuit to predict a subsequent loss of frequency lock between the motor control circuit and a motor while the motor control circuit and the motor remain frequency locked, and based on the prediction, steps to avert a loss of frequency lock during acceleration.

Abstract: An apparatus and associated method for reducing power consumption in an electronic circuit comprising a refresh load device being employed alternatively between an operational mode and a state refresh mode. A supply voltage level to the refresh load device is adjusted in relation to which of the operational and state refresh modes is employed and in relation to which of a primary alternating current derived power source or a backup battery power source is employed.

Abstract: A disc drive having a multi-phase acceleration procedure is disclosed. The multi-phase acceleration procedure accelerates a data storage disc in the disc drive from an initial rotational velocity to a final rotational velocity. As the disc reaches the final rotational velocity, a read/write head operable to access data on the disc is moved by a servo control system from a landing zone to a data region on the disc. An air bearing between a slider of the read/write head and the surface of the disc is created due to the final rotational velocity of the spinning disc. The read/write head may also be moved from the landing zone as the disc reaches an early exit rotational velocity. As such, the multi-phase acceleration procedure continues accelerating the disc until the final rotational velocity to guarantee that the air bearing is maintained between the head and the disc.