Western Digital Technologies, Inc.

Sandisk Corporation

Western Digital Corporation

Other

Gregory B Thelin

Robert D Norman

Anil K Gupta

Karl M J Lofgren

Michael Stephen Rothberg

Dalwinder Singh

Raffi Codilian

Jonathan V Nguyen

Ming Ying Wang

Horia Cristian Simionescu

Chun Sei Tsai

Jeffrey L Williams

Steven R Vasquez

Scott E Burton

Karl M Lofgren

Chandra M Guda

Eric L Severtson

Rebekah A Wilson

Scott McClure

Jillian D Passioukov

Kenneth K Arimura

John Edward Lauber

A write command is received to write data in a target zone including one or more tracks and it is determined whether a data structure is stored in a memory for counting writes performed in a track of the target zone. If such a data structure is not stored in the memory, at least one Low Repeat Write (LRW) data structure is created for the target zone to count writes in sectors of respective tracks of the target zone since creation of the at least one LRW data structure. In another aspect, a write count for a segment is incremented in a data structure for a track to account for a write in the segment. A current overall Track Interference (TI) write count for the target zone is incremented if the incremented segment write count is the highest write count among respective segment write counts in the data structure.

Dynamic track interference write counting for magnetic disks

A data storage device is disclosed comprising a head actuated over a magnetic media comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors. A first codeword is encoded, and the first codeword is written to multiple data sectors of a first data track including a first data sector. A second codeword is encoded, and at least part of the second codeword to is written to the multiple data sectors of a second data track adjacent the first data track including a second data sector adjacent the first data sector of the first data track. The first codeword is partially written to at least the first data sector of the first data track when the first data sector of the first data track is corrupted by writing the second codeword to the second data track.

Data storage device employing partial codeword writes to magnetic media

Controlling a buffered data transfer between a source and a destination by loading a source count value and a destination count value from a buffered data transfer device. A source delta value is computed by subtracting a source previous value from the source count value. The destination count value is adjusted on the buffered data transfer device by adding the source delta value to the destination count value. A destination delta value is computed by subtracting a destination previous value from the destination count value. The source count value is adjusted on the buffered data transfer device by adding the destination delta value to the source count value. A new value for the source previous value is computed by adding the source count value and the destination delta value. A new value for the destination previous value is computed by adding the destination count value and the source delta value.

Controller and method for controlling a buffered data transfer device

A data storage system is disclosed that utilizes high performance media manager transport architecture. In one embodiment, solid-state memory is connected via a bridge interface and media manager transport architecture optimizes the transfer and throughput of data communicated across the bridge. Media transport manager architecture can support reordering and interleaving of storage access commands by using priority and staging mechanisms. Balanced load of solid-state memory, parallel execution of storage access operations, improved concurrency, and increased performance can be attained.

High performance media transport manager architecture for data storage systems

A rotating media storage device (RMSD) that adaptively modifies pre-read operations is disclosed. The RMSD schedules a pre-read data segment on a second track of disk, commands a movable head to seek to the second track, and if an on-track condition is not met for the scheduled pre-read data segment, modifies the pre-read operation. In one example, modifying the pre-read operation includes canceling the pre-read operation and then performing a read data operation.

Adaptively modifying pre-read operations within a rotating media storage device

A disk drive is disclosed having a plurality of disk surfaces, wherein each disk surface comprises a plurality of data tracks, and each data track comprises a plurality of data sectors. When a read command is received from a host, data is read from first and second data sectors on first and second disk surfaces, respectively, in response to the read command, wherein the first data sector stores data at a first data rate, and the second data sector stores data at a second data rate substantially less than the first data rate. The data is transferred to the host at a substantially constant average transfer rate. In this manner, the disk drive does not appear abnormal to a benchmark program that reads a plurality of data sectors across multiple disk surfaces.

Disk drive maintaining a substantially constant host transfer rate when reading data from varying data rate data tracks across multiple disk surfaces

A disk drive is disclosed comprising a plurality of disk surfaces, including first and second disk surfaces. A first physical zone on a first disk surface has a physical zone boundary at a first predetermined radial location, wherein the first predetermined radial location is different from any of the radial locations of the physical zone boundaries on a second disk surface. A plurality of logical zones are identified having logical zone boundaries defined relative to the physical zone boundaries of at least the first and second disk surfaces, wherein the number of logical zones is greater than the number of physical zones for at least one of the disk surfaces. The logical zones are used to find one of the data sectors corresponding to a block address received from a host.

Disk drive employing different zone boundaries across disk surfaces

A mass storage system made of flash electrically erasable and programmable read only memory ('EEPROM') cells organized into blocks, the blocks in turn being grouped into memory banks, is managed to even out the numbers of erase and rewrite cycles experienced by the memory banks in order to extend the service lifetime of the memory system. Since this type of memory cell becomes unusable after a finite number of erase and rewrite cycles, although in the tens of thousands of cycles, uneven use of the memory banks is avoided so that the entire memory does not become inoperative because one of its banks has reached its end of life while others of the banks are little used. Relative use of the memory banks is monitored and, in response to detection of uneven use, have their physical addresses periodically swapped for each other in order to even out their use over the lifetime of the memory.

Wear leveling techniques for flash EEPROM systems

A disk drive is disclosed comprising a disk having a plurality of tracks, wherein each track comprises a plurality of data sectors. The disk drive further comprises a plurality of heads, such as a top head and a bottom head. Control circuitry within the disk drive determines a head-switch preheat period used to format the disk. The head-switch preheat period is calibrated by selecting one of the heads to write a test pattern to the disk, and then preheating the selected head for a preheat period prior to reading the test pattern from the disk to generate a read signal. The head-switch preheat period is determined for the selected head in response to the read signal.

Disk drive determining a head-switch preheat period used to format a disk

A disk drive is disclosed including a disk having a plurality of tracks, wherein each track comprises a plurality of data sectors. A microprocessor executes a write command associated with a disk command data structure by inserting the disk command data structure into a dirty queue, and then executing the write command using the disk command data structure by writing data blocks to a plurality of target data sectors. The disk command data structure is then inserted into a write verify queue, and the disk command data structure is used to perform a write verify operation. The disk command data structure is inserted into an available queue if the target data sectors pass the write verify operation, and the disk command data structure is inserted back into the dirty queue if at least one of the target data sectors fails the write verify operation.

Disk drive employing a disk command data structure for tracking a write verify status of a write command

A disk drive is disclosed which executes a rotational position optimization (RPO) algorithm for selecting a next command to execute out of a plurality of pending commands. The RPO algorithm comprises a first phase and a second phase. The first phase of the RPO algorithm is executed relative to a first priority and in response to at least one non-real-time parameter. The second phase of the RPO algorithm is executed relative to a second priority higher than the first priority and in response to at least one real-time parameter.

Disk drive employing a multi-phase rotational position optimization (RPO) algorithm

A rotating media storage device (RMSD) to adaptively estimate a read access time to a second track based on the radial position of the second track is disclosed. The RMSD includes a disk having at least a first track and a second track and a microprocessor for controlling operations in the RMSD including seek operations. During a seek operation, the microprocessor bins a radial position of the second track and estimates a read access time to the second track based on the binned radial position of the second track.

Adaptively estimating a read access time to a second track based upon the binned radial position of the second track within a rotating media storage device

A disk drive is disclosed comprising a disk having a plurality of tracks, and a head actuated over the disk. Control circuitry heats the head in order to reduce a fly-height of the head, and computes a target servo sector to begin a preheat period. The control circuitry decreases the heat so that the fly-height is increased during at least part of a seek operation to seek the head from a first track to a second track. When the head reaches the target servo sector, the control circuitry increases the heat to decrease the fly-height during the preheat period.

Disk drive decreasing head temperature to increase fly-height during seek operation

A disk drive is disclosed for executing a preemptive multitasking operating system comprising tasks of varying priority, including a disk task for processing disk commands by initiating seek operations and configuring parameters of a read/write channel, a host task for initiating disk commands in response to host commands received from a host computer, a background task for initiating disk commands to perform background operations including a defect scan of the disk, and an execution task for arbitrating the disk commands generated by the host task and the background task and for transmitting the arbitrated disk commands to the disk task.

Disk drive executing a preemptive multitasking operating system comprising tasks of varying priority

A disk drive is disclosed comprising a disk having a plurality of tracks each comprising a plurality of data sectors for storing a plurality of data blocks. A microprocessor initializes a write verify counter in a disk command data structure and executes a write command. The microprocessor executes a write verify operation to verify the recoverability of the data written to a plurality of target data sectors. If the write verify operation fails for a target data sector, the microprocessor updates the write verify counter in the disk command data structure and re-executes the write command and the write verify operation. If the write verify operation fails a number of times such that the write verify counter exceeds a threshold, the microprocessor relocates a data block from the failing target data sector to a spare data sector.

Growing community of inventors

Garden Grove, CA, United States of America

Gregory B Thelin