U.S. patent application number 09/300012 was filed with the patent office on 2002-04-18 for adaptive head address re-map for data storage devices.
Invention is credited to HOUSTON, GEORGE ROBERT, LAMBERTS, BERND, MAN-HON YU, MANTLE.
Application Number | 20020046317 09/300012 |
Document ID | / |
Family ID | 23157288 |
Filed Date | 2002-04-18 |
United States Patent
Application |
20020046317 |
Kind Code |
A1 |
HOUSTON, GEORGE ROBERT ; et
al. |
April 18, 2002 |
ADAPTIVE HEAD ADDRESS RE-MAP FOR DATA STORAGE DEVICES
Abstract
A system, method, and article of manufacture for adaptive
re-mapping of head addresses in a data storage device. A logical
address received by the data storage device is converted into a
corresponding physical address, such as cylinder or track,
read/write head, and sector. The selection of the read/write head
is then re-mapped by the data storage device to a more optimal
selection. Thereafter, the desired operation can be performed using
the physical address including the re-mapped selection of the
read/write heads.
Inventors: |
HOUSTON, GEORGE ROBERT; (SAN
JOSE, CA) ; LAMBERTS, BERND; (CUPERTINO, CA) ;
MAN-HON YU, MANTLE; (SAN JOSE, CA) |
Correspondence
Address: |
GATES & COOPER LLP
HOWARD HUGHES CENTER
6701 CENTER DRIVE WEST, SUITE 1050
LOS ANGELES
CA
90045
US
|
Family ID: |
23157288 |
Appl. No.: |
09/300012 |
Filed: |
April 27, 1999 |
Current U.S.
Class: |
711/5 ; 711/112;
711/203 |
Current CPC
Class: |
G06F 3/0631 20130101;
G06F 3/0607 20130101; G06F 3/0674 20130101 |
Class at
Publication: |
711/5 ; 711/112;
711/203 |
International
Class: |
G06F 012/10 |
Claims
What is claimed is:
1. A method for adaptive re-mapping of head addresses in a data
storage device, comprising: receiving a command at the data storage
device, wherein the command includes a logical address for data
stored on the data storage device; converting the logical address
into a corresponding physical address for the data storage device,
wherein the physical address includes a selection of one or more
read/write heads; re-mapping the selection of the read/write heads
in the data storage device to a more optimal selection of the
read/write heads; and performing the command at the data storage
device using the physical address including the re-mapped selection
of the read/write heads.
2. The method of claim 1, wherein the re-mapped selection of the
read/write heads corresponds to an optimal sequence of read/write
head selections.
3. The method of claim 1, wherein the re-mapped selection of the
read/write head corresponds to a different track format for the
data storage device.
4. The method of claim 1, wherein the more optimal selection of the
read/write heads is based on a type of application accessing the
data storage device.
5. The method of claim 1, wherein the more optimal selection of the
read/write heads is based on empirical knowledge of the data
storage device's performance.
6. The method of claim 1, further comprising dynamically
re-programming the data storage device in order to perform the
re-mapping step.
7. The method of claim 1, wherein the dynamically re-programming
step is performed during manufacturing of the data storage
device.
8. The method of claim 1, wherein the dynamically re-programming
step is performed during field engineering of the data storage
device.
9. A data storage device, comprising: one or more recording
surfaces, one or more read/write heads for writing data to the
recording surfaces and for reading data from the recording
surfaces, and means for performing adaptive re-mapping of the
read/write heads, further comprising: means for receiving a command
including a logical address for data stored on the data storage
device, means for converting the logical address into a
corresponding physical address including a selection of one or more
of the read/write heads, means for re-mapping the selection of the
read/write heads to a more optimal selection of the read/write
heads, and means for performing the command using the physical
address including the re-mapped selection of the read/write
heads.
10. The data storage device of claim 9, wherein the re-mapped
selection of the read/write heads corresponds to an optimal
sequence of read/write head selections.
11. The data storage device of claim 9, wherein the re-mapped
selection of the read/write head corresponds to a different track
format for the data storage device.
12. The data storage device of claim 9, wherein the more optimal
selection of the read/write heads is based on a type of application
accessing the data storage device.
13. The data storage device of claim 9, wherein the more optimal
selection of the read/write heads is based on empirical knowledge
of the data storage device's performance.
14. The data storage device of claim 9, wherein the controller is
dynamically reprogrammed in order to re-map the selection of
read/write heads.
15. The data storage device of claim 9, wherein the data storage
device is dynamically re-programmed during manufacturing.
16. The data storage device of claim 9, wherein the data storage
device is dynamically re-programmed during field engineering.
17. An article of manufacture embodying logic for adaptive
re-mapping of head addresses in a data storage device, comprising:
receiving a command at a data storage device, wherein the command
includes a logical address for data stored on the data storage
device; converting the logical address into a corresponding
physical address for the data storage device, wherein the physical
address includes a selection of one or more read/write heads;
re-mapping the selection of the read/write heads in the data
storage device to a more optimal selection of the read/write heads;
and performing the command at the data storage device using the
physical address including the re-mapped selection of the
read/write heads.
18. The logic of claim 17, wherein the re-mapped selection of the
read/write heads corresponds to an optimal sequence of read/write
head selections.
19. The logic of claim 17, wherein the re-mapped selection of the
read/write head corresponds to a different track format for the
data storage device.
20. The logic of claim 17, wherein the more optimal selection of
the read/write heads is based on a type of application accessing
the data storage device.
21. The logic of claim 17, wherein the more optimal selection of
the read/write heads is based on empirical knowledge of the data
storage device's performance.
22. The logic of claim 17, further comprising dynamically
re-programming the data storage device in order to perform the
re-mapping step.
23. The logic of claim 17, wherein the dynamically re-programming
step is performed during manufacturing of the data storage
device.
24. The logic of claim 17, wherein the dynamically re-programming
step is performed during field engineering of the data storage
device.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to servo control
systems used for positioning read/write transducers in data storage
devices, and more particularly, to a system and method providing an
adaptive re-mapping of head addresses in the data storage
device.
[0003] 2. Description of Related Art
[0004] It is well known in the art to store data on magnetic or
optical disk drives. Data is stored on a disk drive on one or more
tracks of predetermined format disposed on a disk-shaped recording
media. The data is written to and read from the tracks using one or
more transducers, which typically comprise read/write heads.
Reading data from a desired one of the tracks on the disk surfaces
requires knowledge of the read/write head position relative to the
track as the disk rotates and the head is moved across the disk,
and requires precise centering of the head over the disk track.
Conventionally, the read/write head is mounted on a head
positioning assembly that is moved by a servo control.
[0005] When a read/write command is issued by a host computer, it
generally comprises a logical address, such as a logical block
address. This logical address is converted by the servo control
into a physical address, such as a cylinder, read/write head, and
sector. The servo control then operates the head positioning
assembly to move the read/write head to the position corresponding
to the physical address for the reading and writing of data.
[0006] Generally, the conversion of a sequence of logical addresses
to their physical addresses follows a certain sequence of head
switching. Usually, the servo control is programmed with a
predetermined head switching sequence, even though it may not be
the most optimal head switching sequence. Thus, there is a need in
the art for improved methods for adaptively re-mapping head address
selections in order to provide the most optimal sequence.
SUMMARY OF THE INVENTION
[0007] To minimize the limitations in the prior art described
above, and to minimize other limitations that will become apparent
upon reading and understanding the present specification, the
present invention discloses a system and method for adaptive
re-mapping of head addresses in a data storage device. A logical
address received by the data storage device is converted into a
corresponding physical address, such as cylinder or track,
read/write head, and sector. The selection of the read/write head
is then re-mapped by the data storage device to a more optimal
selection. Thereafter, the desired operation can be performed using
the physical address including the re-mapped selection of the
read/write heads.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Referring now to the drawings in which like reference
numbers represent corresponding parts throughout:
[0009] FIG. 1 is an illustration of an exemplary disk drive
according to the preferred embodiment of the present invention;
and
[0010] FIG. 2 is a flowchart that illustrates the logic performed
by preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] In the following description of the preferred embodiment,
reference is made to the accompanying drawings which form a part
hereof, and in which is shown by way of illustration the specific
embodiment in which the invention may be practiced. It is to be
understood that other embodiments may be utilized and structural
changes may be made without departing from the scope of the present
invention.
[0012] Disk Drive Components
[0013] FIG. 1 is a block diagram of an exemplary disk drive 10
according to the preferred embodiment of the present invention.
Those skilled in the art will recognize that the exemplary
components and structure illustrated in FIG. 1 are not intended to
limit the present invention. Indeed, those skilled in the art will
recognize that other alternative embodiments may be used without
departing from the scope of the present invention.
[0014] The disk drive 10 stores information on the surfaces of one
or more stacked disks 12 in the form of transitions or patterns
formed on one or more data tracks. The disks 12 are rotatably
mounted on a spindle motor 14. Transitions are sensed or "read"
from the disk 12 surfaces via one or more transducers 16, known as
read/write heads, supported in dose proximity to the disk 12
surfaces by a head positioning assembly 18, wherein the transducers
16 convert the transitions into electrical signals. The head
positioning assembly 18 positions the transducers 16 over the disk
12 surfaces in a linear or rotary manner by operation of a voice
coil motor (VCM) 20, which is controlled by a servo control loop
that includes a servo controller 22.
[0015] Data is organized on the disks 12 using a series of
concentric, radially spaced tracks, wherein a "cylinder" comprises
a stack of these tracks across multiple disk 12 surfaces. Each
track is divided into a plurality of sectors formatted in a
predetermined, standard manner. The format specifies the sequence
and location of certain types of information such as track number,
sector number, data field, etc. A number of different formats may
be used for the tracks.
[0016] When a read/write command is issued by a host computer 24,
the servo controller 22 (or an interface processor or some other
electronics within the disk drive 10) converts logical addresses,
i.e., logical block addresses, into their respective physical
addresses, i.e., cylinder, read/write head, and sector, and then
proceeds to read from and/or write to the data at the physical
addresses by moving the read/write heads to the corresponding
position on the disk 12 surfaces.
[0017] For example, using a conventional track format for a single
disk 12 having two recording surfaces, each track switch requires a
head 16 switch operation from head #0 to head #1, or from head #1
to head #0, with the switch from head #1 to head #0 also
incrementing the cylinder number. In this format, the sequence is
cylinder 0-head 0 (track 0), cylinder 0-head 1 (track 1), cylinder
1-head 0 (track 2), etc., across the surface of the disk 12 from
its outer diameter to its inner diameter. Alternative formats
include sequential track format and zoned-sequential track format,
among others.
[0018] The present invention addresses the track format of disk
drives 12 and the way that the read/write heads 16 are controlled
in response thereto. As noted above, there are a number of
different track formats available, as well as a number of different
options regarding the sequence of head 16 switches corresponding to
those track formats. Some options may favor head 16 switches over
track-to-track switches, whereas other options may favor
track-to-track switches over head 16 switches, or may differ in the
head 16 switching sequence, e.g., all even heads 16 first, or all
odd heads 16 first, or head #0 to head #N followed by head #N to
head #0, etc.
[0019] Common to all these schemes is a certain complexity in the
programming of the disk drive 10, in order to convert a sequence of
logical addresses into a sequence of physical addresses that may
include a sequence of head 16 switches. The present invention
reduces this complexity and therefore increases design robustness
by encapsulating read/write head 16 mappings within the disk drive
10, so that the read/write head 16 mappings may be changed as
desired or required. When requests are received from the host
computer 24 that address data on the disk drive 10 using one head
16 mapping scheme, the heads 16 are remapped using another more
optimal scheme. Specifically, the read/write head 16 mappings can
be changed as desired or required.
[0020] For example, for a particular disk drive 10, the originally
programmed sequence of head 16 switches may be inefficient and
another sequence of head 16 switches may be more optimal.
Inefficiency and optimality may depend on any number of factors,
such as the precision or alignment of parts within the disk drive
10, or the type of application accessing the disk drive 10, e.g.,
purely sequential access of video data streams versus highly random
access of database tables, or in light on empirical knowledge
concerning the performance of the disk drive 10 in various
scenarios.
[0021] In one embodiment of the present invention, the optimal head
16 switching sequence is determined during manufacturing,
programming is provided within the disk drive 10 to map the heads
16 accordingly, and the disk drive 10 is formatted in accordance
with the programming. In another embodiment of the present
invention, the optimal head 16 switching sequence is determined
during field engineering, the disk drive 10 is dynamically
re-programmed to map the heads 16 accordingly, and the disk drive
10 is reformatted in accordance the re-programming.
[0022] Logic of the Preferred Embodiment
[0023] FIG. 2 is a flow chart illustrating the logic performed by
the preferred embodiment of the present invention in the adaptive
re-mapping of head 16 addresses in the disk drive 10.
[0024] Block 26 represents the disk drive 10 being dynamically
re-programmed to specify the best head 16 switching sequence.
Generally, this dynamically re-programming of the disk drive 10 is
performed during the manufacturing (and formatting) of the disk
drive 10 or during field engineering (and re-formatting) of the
disk drive 10.
[0025] Block 28 represents the disk drive 10 receiving a read/write
command, wherein the command includes a logical address for data
stored on the disk drive 10.
[0026] Block 30 represents the disk drive 10 (specifically,
specifically, the interface processor code of the controller 22, an
interface processor, or some other device within the disk drive 10)
converting the logical address into a corresponding physical
address for the disk drive 10, wherein the physical address
includes a selection of one or more read/write heads 16.
[0027] Block 32 represents the disk drive 10 (specifically, the
adaptive head address re-mapping code of the servo controller 22,
an interface processor, or some other device within the disk drive
10) re-mapping the selection of the read/write heads 16 to a more
optimal selection of the read/write heads 16. Generally, this
optimal selection may comprise an optimal sequence of read/write
head 16 selections.
[0028] Block 34 represents the disk drive 10 performing the
read/write command using the physical address including the
re-mapped selection of the read/write heads 16.
[0029] Conclusion
[0030] This concludes the description of the preferred embodiment
of the present invention. Generally, preferred embodiment of the
present invention is implemented as programming within a servo
controller, an interface controller, or some other device within
the disk drive. This programming comprises instructions and/or data
that is embodied in or retrievable from a device, medium, or
carrier. Moreover, these instructions and/or data, when read,
executed, and/or interpreted, perform the steps necessary to
implement and/or use the present invention.
[0031] Thus, the present invention may be implemented as a method,
apparatus, or article of manufacture using standard programming
and/or engineering techniques to produce software, firmware,
hardware, or any combination thereof. The term "article of
manufacture", or alternatively, "computer program carrier", as used
herein is intended to encompass logic or instructions embodied in
or accessible from any device, carrier, or media.
[0032] Of course, those skilled in the art will recognize many
modifications may be made to this implementation without departing
from the scope of the present invention. Indeed, those skilled in
the art will recognize that any combination of the above
components, or any number of different components, including
programmable or non-programmable devices and circuits, may be used
to implement the present invention, so long as similar functions
are performed thereby.
[0033] In addition, the present invention can be applied to any
number of different data storage devices. For example, any type of
rotating data storage device, such as a magnetic, optical, or other
device, could benefit from the present invention. Moreover,
different electronics or logic could be used to implement the
present invention.
[0034] In conclusion, the present invention discloses a system and
method for adaptive re-mapping of head addresses in a data storage
device. A logical address received by the controller is converted
into a corresponding physical address, such as cylinder or track,
read/write head, and sector. The selection of the read/write head
is then re-mapped by the controller to a more optimal selection.
Thereafter, the desired operation can be performed using the
physical address including the re-mapped selection of the
read/write heads.
[0035] The foregoing description of the preferred embodiment of the
invention has been presented for the purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed. Many modifications and
variations are possible in light of the above teaching. It is
intended that the scope of the invention be limited not with this
detailed description, but rather by the claims appended hereto.
* * * * *