US 6,965,966 B1Granted

Disk drive pre-computing seek parameters for a continuation track and a next command to facilitate continuing a read-ahead or aborting the read-ahead

AssigneeWestern Digital Technologies, Inc.

InventorsMichael S. Rothberg, Jonathan V. Nguyen, Gregory B. Thelin

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Abstract

A disk drive is disclosed which pre-computes first seek parameters to seek to a continuation track storing read-ahead data, and second seek parameters to seek to a target track of a next command. An abort window is also computed for aborting a read-ahead operation early in order to seek to the target track of the next command. If the head enters the abort window, the disk drive is programmed with the second seek parameters to seek to the target track of the next command. If the read-ahead operation requires a seek to the continuation track prior to the head entering the abort window, the disk drive is programmed with the first seek parameters to seek to the continuation track.

Claims12

Dependent claims

A disk drive comprising:

(a) a disk comprising a plurality of tracks, each track comprising a plurality of blocks and a plurality of embedded servo sectors recorded at a predetermined interval;
(b) a head actuated radially over the disk;
and
(c) a disk controller for:
executing a first command by reading read data from a selected one of the tracks and executing a read-ahead operation by reading read-ahead data from the disk following the read data;
pre-computing first seek parameters to seek the head to a continuation track storing at least part of the read-ahead data;
computing an abort window in response to a second command for aborting the read-ahead operation of the first command;
pre-computing second seek parameters to seek the head to a target track of the second command;
processing the embedded servo sectors to detect when the head enters the abort window;
if the head enters the abort window, programming the disk drive with the second seek parameters to seek the head to the target track of the second command;
and
if the read-ahead operation requires a seek to the continuation track prior to the head entering the abort window, programming the disk drive with the first seek parameters to seek the head to the continuation track.

9 more elements

A method of operating a disk drive, the disk drive comprising a disk having a plurality of tracks, each track comprising a plurality of blocks and a plurality of embedded servo sectors recorded at a predetermined interval, and a head actuated radially over the disk, the method comprising the steps of:

(a) receiving a first command from a host computer, the first command comprising a command size representing a number of blocks of read data to read from the disk;
(b) executing the first command by reading the read data from a selected one of the tracks and executing a read-ahead operation by reading read-ahead data from the disk following the read data;
(c) pre-computing first seek parameters to seek the head to a continuation track storing at least part of the read-ahead data;
(d) receiving a second command from the host computer;
(e) computing an abort window in response to the second command for aborting the read-ahead operation of the first command;
(f) pre-computing second seek parameters to seek the head to a target track of the second command;
(g) processing the embedded servo sectors to detect when the head enters the abort window;
(h) if the head enters the abort window, programming the disk drive with the second seek parameters to seek the head to the target track of the second command;
and
(i) if the read-ahead operation requires a seek to the continuation track prior to the head entering the abort window, programming the disk drive with the first seek parameters to seek the head to the continuation track.

7 more elements

Dependencies are inferred from the claim text.