Abstract: Method and apparatus for enhancing reliability and integrity of data stored in a non-volatile memory, such as in a solid-state drive (SSD) having an array of flash memory cells. In accordance with various embodiments, a controller is adapted to harden data stored in a first location of said memory in relation to a detected loss of retention characteristics of the first location. In some embodiments, the data are hardened by storing redundancy information associated with said data in a second location of said memory. The redundancy information can be a redundant set of the data or higher level error correct codes (ECC). The hardened data can be recovered to the host during a read operation by accessing the data stored in both the first and second locations.

Abstract: In general, this disclosure relates to garbage collection in a storage device. Aspects of this disclosure describe techniques to identify one or more candidate memory storage blocks that should be recycled during garbage collection. The one or more candidate memory storage blocks may be identified based at least on monitored soft metrics of the candidate memory storage blocks. During garbage collection, the identified one or more candidate memory storage blocks may be recycled to free up storage space.

Abstract: In general, this disclosure relates to storage of logical blocks in a storage device. Aspects of this disclosure describe techniques to monitor the frequency of access of one or more logical blocks referenced by one or more logical block addresses. Based on the frequency of access, in non-limiting aspects of this disclosure, a controller may select one or more physical blocks of a common memory storage block. The storage device may store the logical blocks in the selected physical blocks.

Abstract: The read channel of a solid state non-volatile memory may be configured to compensate for shifts in the threshold voltages of memory cells of the memory. A log of write time information and write temperature information from one or more write operations is stored in a data unit header. The read channel configuration, which may include reference voltages used for the read operation, is determined using the write time information and the write temperature information. Memory cells of the data unit are read using the configured read channel. A historical profile spanning multiple write operations may also be developed and used to configure the read channel.

Abstract: The read channel of a solid state non-volatile memory may be configured to compensate for shifts in the threshold voltages of memory cells of the memory. A log of write time information and write temperature information from one or more write operations is stored in a data unit header. The read channel configuration, which may include reference voltages used for the read operation, is determined using the write time information and the write temperature information. Memory cells of the data unit are read using the configured read channel. A historical profile spanning multiple write operations may also be developed and used to configure the read channel.

Abstract: In general, this disclosure is directed to techniques for adjusting the timing of operations for a storage device. According to one aspect of the disclosure, a method includes receiving, with at least one device, a workload indicator. The method further includes adjusting, with the at least one device, an operation execution time for the storage device responsive to at least the workload indicator. In some examples, the workload indicator may include a host demand indicator. In additional examples, the workload indicator may include a resource utilization indicator. In further examples, the operation execution time may be one of a write operation execution time or a read operation execution time.

Abstract: Method and apparatus for enhancing reliability and integrity of data stored in a non-volatile memory, such as in a solid-state drive (SSD) having an array of flash memory cells. In accordance with various embodiments, a controller is adapted to harden data stored in a first location of said memory in relation to a detected loss of retention characteristics of the first location. In some embodiments, the data are hardened by storing redundancy information associated with said data in a second location of said memory. The redundancy information can be a redundant set of the data or higher level error correct codes (ECC). The hardened data can be recovered to the host during a read operation by accessing the data stored in both the first and second locations.

Abstract: An example method includes providing at least two data storage areas in a memory, providing a first amount of over-provisioning for a first of the at least two data storage areas and a second amount of over-provisioning for a second of the at least two data storage areas, categorizing data based on a characteristic of the data, and storing the data in one of the at least two data storage areas based on the categorization.

Abstract: A data storage apparatus and associated method involving a memory with a plurality of storage elements defining an associated set of stored data, and memory control logic that, responsive to a request to store first data in a first storage element of the plurality of storage elements, computes without storing to any of the plurality of storage elements first redundancy data for the associated set of stored data inclusive of the first data.

Abstract: In general, this disclosure relates to garbage collection in a storage device. Aspects of this disclosure describe techniques to identify one or more candidate memory storage blocks that should be recycled during garbage collection. The one or more candidate memory storage blocks may be identified based at least on monitored soft metrics of the candidate memory storage blocks. During garbage collection, the identified one or more candidate memory storage blocks may be recycled to free up storage space.

Abstract: In general, this disclosure relates to storage of logical blocks in a storage device. Aspects of this disclosure describe techniques to monitor the frequency of access of one or more logical blocks referenced by one or more logical block addresses. Based on the frequency of access, in non-limiting aspects of this disclosure, a controller may select one or more physical blocks of a common memory storage block. The storage device may store the logical blocks in the selected physical blocks.

Abstract: An apparatus comprises an optical transducer positioned adjacent to a storage medium and including a waveguide and a grating for coupling light into the waveguide, a light source transmitting light to the grating, and a detector for detecting a portion of the light, wherein the detected portion of the light has a magnitude that varies in response to the amount of light coupled into the waveguide.

Abstract: An apparatus comprises a moveable arm for positioning an optical transducer adjacent to a storage medium, a stationary light source, and a moveable mirror mounted at a pivot axis of the arm for reflecting light from the light source to the optical transducer. An actuator can be provided for rotating the moveable mirror through an angle of about one half of an angle of rotation of the moveable arm.

Abstract: A suspension arm for an optical transducer comprises a load beam, a slider coupled to the load beam by a gimbal assembly and including an optical transducer positioned adjacent to an end of the slider facing a pivot point of the suspension arm, and an optical fiber for transmitting light toward the transducer, wherein an end of the optical fiber is positioned adjacent to the transducer such that light emitted from the fiber passes directly to the transducer. Disc drives that include the suspension arm, and a method of transmitting light to an optical transducer, are also included.

Abstract: An actuator control system for a two-stage actuator system of a disc drive has a first, or primary, stage actuator consisting of a voice coil motor that positions the head relative to a disc and a microactuator that alters the actuator system without operation of the voice coil motor. A control loop includes a controller responsive to seek commands to operate the voice coil motor, thereby moving the head relative to the disc. An active damping circuit is coupled to the head to operate the microactuator to damp resonance modes of the actuator system.

Abstract: A disc drive includes a base and a disc rotatably attached to the base. The disc has an inner diameter and an outer diameter and a plurality of tracks. Information is written on the plurality of tracks. The plurality of tracks are written at a variable track pitch. The tracks positioned near the outer diameter are wider in pitch than the tracks positioned near the inner diameter. The plurality of tracks further include a first group of tracks written at a first track pitch, and a second group of tracks written at a second track pitch. The track pitch of each of the first group and the second group of tracks is selected such that the percentage of track misregistration for each group will be substantially the same. This method provides a means to increase storage capacity for a predetermined track misregistration budget.

Abstract: A disc storage system is provided which includes a servo control loop for compensating for repeatable runout. Repeatable runout is compensated using table entries of the form Comp Value(k+1)=Comp Value(k)+K&PHgr;(z)RRO(k), where K is a learning rate; k is iteration number &PHgr;(z) is a filter and RRO(k) is the repeatable runout error. Further, &rgr;(j&ohgr;)=|1−K&PHgr;(j&ohgr;)/(1+PC(j&ohgr;)|<1 needs to be satisfied, where PC(j&ohgr;) is an open loop frequency response of the servo loop. The filter can comprise a order filter.

Abstract: A method and apparatus are provided for generating an adaptive feedforward cancellation signal for a next sector of a disc in a disc drive. The cancellation signal includes at least one tap weight multiplied by at least one trigonometric function. To form the cancellation signal, the method and apparatus first determine a servo loop transfer function relative to a feedforward cancellation component in the disc drive. The transfer function is then inverted to form filter parameters. A position error value is then measured for a current signal and is passed through a filter formed from the filter parameters. This creates a filtered position error value that is used with the tap weights of a current sector to determine the tap weights for the cancellation signal of the next sector.

Abstract: An HDA includes a base, a disc stack coupled to a spindle rotatably attached to the base by a spindle shaft and spindle bearing. An actuator assembly is pivotally attached to the base at a pivot shaft. Attached to one end of the actuator assembly proximal the disc stack is one or more transducers for reading/writing information from/to the discs. A servo writer includes a controller for moving the actuator during the servo writing process. The controller moves the servo writer at the cage frequency of the spindle bearing to lessen the relative motion between the transducer head and the disc as the servo information is written to the disc. The controller also may be programmed to move the transducer at both the spindle rotation frequency and the cage frequency of the spindle bearing to lessen the relative motion between the transducer and the disc during the servo writing process.

Abstract: A method and apparatus are provided for positioning a head over a disc in a disc drive while maintaining servo loop stability. The apparatus includes an actuator-head assembly having a large-scale actuator and a micro-actuator that are both able to move the head over the disc. A saturation adjustment component detects when a micro-actuator controller is producing a micro-actuator control value that will saturate the micro-actuator. Using the micro-actuator control value, the saturation adjustment component generates a saturation error value. An adaptive anti-windup circuit transfers control to the large-scale actuator when the saturation error value is generated by the saturation adjustment component.