Seagate Technology Incorporated

KokChoon See

CheeWai Lum

LingLing Chua

YongPeng Chng

Wesley Chan

PohGuat Bay

CheeSeng Toh

LianYong Tan

ChweeFern Ee

KokSeng Lim

An intelligent write command routine improves the operational efficiency of a data storage device (DSD) by avoiding media access of the disk when a logical block address (LBA) and the physical sector are unaligned, thus reducing write time. When a write command is received by the DSD from the host, the intelligent write command routine maintains the read data of the read buffer, instead of clearing the read buffer and performing a read of the target sector on the disk per standard protocol. The intelligent write command copies the necessary adjacent sector data from the read buffer as a data patch to the write buffer to splice around the write data received with the write command. Following each write command, the data written to the disk in the write buffer is copied to the read buffer. The read buffer is maintained with the most current data on the disk and does not need to be flushed unless the LBA of the write command is beyond the data ranges stored in the read buffer.

Buffer management for increased write speed in large sector data storage device

Method and apparatus for servicing commands such as the type issued by a host device to load an operating system from an associated data storage device. A controller is adapted to, upon receipt of a selected command sequence comprising a first command followed by a second command, determine an elapsed time interval between the first and second commands. The controller further uses the elapsed time interval to subsequently service the first and second commands during a subsequent receipt of the selected command sequence. Preferably, a command history table is generated to list the commands in the command sequence and the associated time intervals, and to use the time intervals to predict when the next command will occur. Readback data are pre-fetched to a buffer to expedite servicing of the commands, and the controller selectively enters one or more reduced power modes between successive commands to reduce power consumption levels.

Expedited and low power command sequence servicing

A method of performing a retry procedure may begin with detecting an error in a first zone of a data storage medium. Upon detecting the error, it is determined whether any retry procedure of a sequence of retry procedures has been performed upon detecting a previous error in the first zone. If a first retry procedure of the sequence was unsuccessfully performed upon detecting the previous error, there is performed a second retry procedure that follows next after the first retry procedure in the sequence.

Performing retry operations

A smart retry operation, or set of retry procedures to be performed in sequence, that optimizes itself for a data storage device's individual characteristics, including variations across the data storage media and variations introduced as the device degrades over time, is disclosed. The data storage media (e.g. a disc in a disc drive) is divided into a number of zones and a separate smart retry operation is maintained for each zone. The data storage media is then tested to find errors correctable by the retry procedures. A statistical likelihood for each retry procedure is developed. The sequential order of the retry procedures in each zone's operation is then optimized based on the statistics. A single read/write retry sequences or separate read and write retry sequences may be maintained. The retry operations may be constantly re-optimized over the lifetime of the data storage device.

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KokChoon See