US 2003/0145164 A1 · Read on arrival scheme for a disc drive

Abstract

A read-on-arrival scheme for reading data stored on a track of a data storage disc is disclosed. The track is divided into a plurality of sequentially arranged data sectors. Each data sector stores a block of data. A host computer issues a read command requesting retrieval of a segment of data blocks stored on a plurality of the data sectors. The segment may include a target data segment as well as a pre-fetch and post-fetch data segment. The read command specifies a target sector that a transducer is to initially access on the track. Upon receipt of the read command, components of a disc drive move the transducer to the track for access of the segment requested in the command. The disc drive components enable the transfer of data regardless of whether the transducer first accesses a sector located in sequential order prior to or following the target sector.

Claims30

Dependent claims

A method for transferring data between a rotating data storage disc and an external environment via a transducer accessing sequentially arranged data sectors on a track on the data storage disc, wherein data read from the disc by the transducer is placed in a buffer memory, the method comprising:

(a) receiving a read command specifying a target sector as a beginning sector storing a first data block of a data segment to be read;
(b) reading a first portion of the data segment as the transducer accesses one or more data sectors on the track beginning with an initial sector located on the track sequentially following the target sector and ending at an end sector as the disc rotates under the transducer in a predetermined direction;
(c) waiting for the transducer to access an index sector as the disc rotates under the transducer in the predetermined direction;
and
(d) reading a second portion of the data segment as the transducer accesses another one or more data sectors on the track beginning with the index sector and ending at a stop sector adjacent to and sequentially preceding the initial sector as the disc rotates under the transducer in the predetermined direction such that the target sector is included in the one or more data sectors accessed by the transducer as the transducer reads the second portion of the data segment.

2 more elements

In a disc drive, a method for controlling a transfer of data between a rotating data storage disc and an external environment via a transducer accessing sequentially arranged data sectors on a track on the data storage disc, wherein data read from the disc by the transducer is placed in a buffer memory, the method comprising:

(a) receiving a read command requesting retrieval of a data segment stored on a target area of the track and beginning with a data block stored on a specified target sector, pre-fetch data stored on a specified pre-fetch portion on the track and post-fetch data stored on a specified post-fetch portion on the track;
(b) enabling the transfer of data from the disc to the buffer beginning as the transducer accesses an initial sector on the track such that data blocks stored on the initial sector and one or more sectors accessed by the transducer thereafter are read and provided to the buffer;
(c) disabling the transfer of data from the disc to the buffer after the transducer accesses and reads data stored on an end sector of the post-fetch data portion if the initial sector follows the target sector in sequential arrangement;
(d) enabling the transfer of data from the disc to the buffer as the transducer accesses a pre-fetch target sector of the specified pre-fetch data portion such that data blocks stored on the pre-fetch target sector and one or more sectors accessed by the transducer thereafter are read and provided to the buffer;
and
(e) disabling the transfer of data from the disc to the buffer as the transducer accesses and reads data stored on a data sector adjacent to and sequentially preceding the initial sector.

3 more elements

Dependencies are inferred from the claim text.

Read on arrival scheme for a disc drive

Life of this patent

Read on arrival scheme for a disc drive

Life of this patent

Abstract

Claims30