U.S. patent application number 09/928622 was filed with the patent office on 2002-02-21 for energy detect with auto pair select.
Invention is credited to Berman, Mark, Thousand, Richard Glen.
Application Number | 20020023234 09/928622 |
Document ID | / |
Family ID | 26919057 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020023234 |
Kind Code |
A1 |
Berman, Mark ; et
al. |
February 21, 2002 |
Energy detect with auto pair select
Abstract
Energy detect with auto pair select. The present invention is
operable without `a priori` knowledge of the pairs' connectivity.
In addition, the present invention is operable within systems
performing automatic detection of connectivity in systems that
employ the Ethernet based media dependent interface crossover
(MDIX). Where there has been some cross-over of pairs within the
system, a situation not uncommon in many networks, the present
invention is operable to perform energy management even without
having any knowledge of the pair connectivity. Knowledge relating
to the energy of multiple pairs is used to perform energy detect
and management. A state machine operates in performing the analysis
of the energy using a qualified energy level. The present invention
is also operable within systems that do not employ
auto-negotiation. In systems where auto-negotiation is performed,
the present invention is performed before the auto-negotiation to
determine if an operable partner exists within the network.
Inventors: |
Berman, Mark; (Newport
Coast, CA) ; Thousand, Richard Glen; (Irvine,
CA) |
Correspondence
Address: |
Shayne X. Short, Ph.D.
Garlick, Harrison, & Markison, L.L.P.
P.O. Box 160727
Austin
TX
78716-0727
US
|
Family ID: |
26919057 |
Appl. No.: |
09/928622 |
Filed: |
August 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60224846 |
Aug 11, 2000 |
|
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|
Current U.S.
Class: |
713/300 |
Current CPC
Class: |
G06F 1/3209
20130101 |
Class at
Publication: |
713/300 |
International
Class: |
G06F 001/26; G06F
001/28; G06F 001/30 |
Claims
What is claimed is:
1. An energy detect with auto pair select system, comprising: a
device that is operable to perform energy detection with auto pair
selection; a plurality of wire pairs that is communicatively
coupled to the device; and wherein the device generates a qualified
energy by considering an energy associated with at least two wire
pairs within the plurality of wire pairs; the device uses the
qualified energy to determine whether at least one additional
device is communicatively coupled to the device via at least one
wire pair within the plurality of wire pairs; and the device
performs auto power down when no device is communicatively coupled
to the device via the wire pair.
2. The energy detect with auto pair select system of claim 1,
wherein the auto power down comprises a partial auto power
down.
3. The energy detect with auto pair select system of claim 1,
wherein the device performs auto media dependent interface
crossover functionality when the wire pair is transposed with at
least one additional wire pair.
4. The energy detect with auto pair select system of claim 1,
wherein the device subtracts a link pulse energy from the energy
when the device transmits a link pulse to generate the qualified
energy, the link pulse energy is associated with a link pulse that
is transmitted from the device.
5. The energy detect with auto pair select system of claim 4,
further comprising an OR gate that sums energies on each of the
plurality of wire pairs; and an AND gate that suppresses the link
pulse energy from the sum of the energies of each of the plurality
of wire pairs.
6. The energy detect with auto pair select system of claim 1,
wherein the device uses the energy of at least one wire pair within
the plurality of wire pairs as the qualified energy when the device
does not transmit a link pulse.
7. The energy detect with auto pair select system of claim 1,
wherein the plurality of wire pairs comprises at least one of a
receive wire pair and a transmit wire pair.
8. The energy detect with auto pair select system of claim 1,
further comprising a state machine that is operable to determine
connectivity of the device with the plurality of wire pairs.
9. The energy detect with auto pair select system of claim 8,
wherein the state machine is operable to change an operational
state of the device based on whether at least one additional device
is communicatively coupled to the device via at least one wire pair
within the plurality of wire pairs.
10. The energy detect with auto pair select system of claim 1,
wherein the device performs wake up from a standby state when the
device determines that the at least one additional device is
communicatively coupled to the device via the wire pair.
11. An energy detect with auto pair select system, comprising: a
device that is operable to perform energy detection with auto pair
selection; a wire pair that is communicatively coupled to the
device; and wherein the device determines whether the wire pair
comprises an energy; the device subtracts a link pulse energy from
the energy when the device transmits a link pulse to generate a
qualified energy, the link pulse energy is associated with a link
pulse that is transmitted from the device; the device uses the
energy as the qualified energy when the device does not transmit a
link pulse; and the device uses the qualified energy to determine
whether at least one additional device is communicatively coupled
to the device via the wire pair.
12. The energy detect with auto pair select system of claim 11,
wherein the device performs auto media dependent interface
crossover functionality when the wire pair is transposed with at
least one additional wire pair.
13. The energy detect with auto pair select system of claim 12,
wherein the device performs the auto media dependent interface
after determining whether the at least one additional device is
communicatively coupled to the device via the wire pair.
14. The energy detect with auto pair select system of claim 11,
wherein the device performs auto power down when no device is
communicatively coupled to the device via the wire pair.
15. The energy detect with auto pair select system of claim 14,
wherein the auto power down comprises a partial auto power
down.
16. The energy detect with auto pair select system of claim 11,
wherein the device performs wake up from a standby state when the
device determines that the at least one additional device is
communicatively coupled to the device via the wire pair.
17. The energy detect with auto pair select system of claim 11,
wherein the device comprises a state machine that is operable to
change an operational state of the device based on whether the at
least one additional device is communicatively coupled to the
device via the wire pair.
18. The energy detect with auto pair select system of claim 11,
further comprising at least one additional wire pair; and wherein
the device sums energy on the wire pair and energy on the at least
one additional wire pair.
19. The energy detect with auto pair select system of claim 18,
wherein the wire pair comprises at least one of a transmit pair and
a receive pair; and the at least one additional pair comprises at
least one of a transmit pair and a receive pair.
20. An energy detect with auto pair select system, comprising: a
device that is operable to perform energy detection with auto pair
selection; a plurality of wire pairs that is communicatively
coupled to the device; a state machine that is operable to
determine connectivity of the device; and wherein the device
performs auto media dependent interface crossover functionality
when at least two wire pairs within the plurality of wire pairs are
transposed; the device determines whether at least one wire pair
within the wire pair comprises an energy; the device subtracts a
link pulse energy from the energy, when the device transmits a link
pulse, to generate a qualified energy, the link pulse energy is
associated with a link pulse that is transmitted from the device;
the device uses the energy as the qualified energy when the device
does not transmit a link pulse; the device provides the qualified
energy to the state machine; the state machine determine whether at
least one additional device is communicatively coupled to the
device via the wire pair; and the device performs energy savings
management.
21. The energy detect with auto pair select system of claim 20,
wherein the state machine is contained within the device.
22. The energy detect with auto pair select system of claim 20,
wherein the device is operable within at least one of a standby
state and an awake state as determined by the state machine.
23. The energy detect with auto pair select system of claim 20,
wherein the device performs auto power down when the device
determines that no device is communicatively coupled to the device
via the wire pair.
24. The energy detect with auto pair select system of claim 20,
further comprising an OR gate that sums energies on each of the
plurality of wire pairs; and an AND gate that suppresses the link
pulse energy from the sum of the energies of each of the plurality
of wire pairs.
25. An energy detect with auto pair select method, the method
comprising: performing energy detection of a plurality of wire
pairs, at least one wire pair within the plurality of wire pairs is
communicatively coupled to a device; generating a qualified energy
by considering an energy associated with at least two wire pairs
within the plurality of wire pairs; determining whether at least
one additional device is communicatively coupled to the device via
at least one wire pair within the plurality of wire pairs; and
performing auto power down when no device is communicatively
coupled to the device via the wire pair.
26. The method of claim 25, further comprising performing auto
negotiation between the device and at least one additional
device.
27. The method of claim 25, further comprising waking up the device
from a standby state.
28. The method of claim 25, wherein the auto power down comprises a
partial auto power down.
29. The method of claim 25, further comprising performing auto
media dependent interface crossover functionality when the wire
pair is transposed with at least one additional wire pair.
30. The method of claim 25, further comprising summing energies on
each of the plurality of wire pairs; and suppressing energy
associated with a transmitted link pulse from the sum of the
energies of each of the plurality of wire pairs, the transmitted
link pulse being transmitted from a device.
31. The method of claim 25, further comprising using the energy of
at least one wire pair within the plurality of wire pairs as the
qualified energy when the device does not transmit a link
pulse.
32. The method of claim 25, wherein the plurality of wire pairs
comprises at least one of a receive wire pair and a transmit wire
pair.
33. The method of claim 25, further comprising employing a state
machine to determine connectivity of the device with the plurality
of wire pairs.
34. The method of claim 33, wherein the state machine is operable
to change an operational state of the device based on whether at
least one additional device is communicatively coupled to the
device via at least one wire pair within the plurality of wire
pairs.
35. The method of claim 25, wherein the device performs wake up
from a standby state when the device determines that the at least
one additional device is communicatively coupled to the device via
the wire pair.
36. An energy detect with auto pair select method, the method
comprising: performing energy detection with auto pair selection on
a device having a wire pair communicatively coupled thereto;
determining whether the wire pair comprises an energy; subtracting
a link pulse energy from the energy, when the device transmits a
link pulse, to generate a qualified energy, the link pulse energy
is associated with a link pulse that is transmitted from the
device; using the energy as the qualified energy when the device
does not transmit a link pulse; and using the qualified energy to
determine whether at least one additional device is communicatively
coupled to the device via the wire pair.
37. The method of claim 36, further comprising performing auto
media dependent interface crossover functionality when the wire
pair is transposed with at least one additional wire pair.
38. The method of claim 37, further comprising performing the auto
media dependent interface after determining whether the at least
one additional device is communicatively coupled to the device via
the wire pair.
39. The method of claim 36, further comprising performing auto
power down when no device is communicatively coupled to the device
via the wire pair.
40. The method of claim 39, wherein the auto power down comprises a
partial auto power down.
41. The method of claim 36, further comprising waking up the device
from a standby state after determining that the at least one
additional device is communicatively coupled to the device via the
wire pair.
42. The method of claim 36, further comprising employing a state
machine to change an operational state of the device based on
whether the at least one additional device is communicatively
coupled to the device via the wire pair.
43. The method of claim 36, wherein at least one additional wire
pair is communicatively coupled to the device; and further
comprising summing energy on the wire pair and energy on the at
least one additional wire pair.
44. The method of claim 43, wherein the wire pair comprises at
least one of a transmit pair and a receive pair; and the at least
one additional pair comprises at least one of a transmit pair and a
receive pair.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The invention relates generally to energy detect and auto
power down devices; and, more particularly, it relates to a system
and method operable to perform energy detection and auto pair
selection within a device that is operable to perform power
savings.
[0003] 2. Related Art
[0004] Prior art energy detection systems depend intrinsically upon
a priori knowledge of the connectivity of wires, and pairs of
wires, within their respective systems to perform energy savings.
That is to say, a definitive knowledge of the connectivity to the
system is required to perform proper power savings functionality.
The operation of such systems becomes increasingly difficult when
the wires have been improperly connected. In come cases, the system
will fail to function at all. That is to say, when there is no
knowledge of the connectivity, there is an inability within the
system to perform proper power management.
[0005] Traditionally, networks were often designed to include a hub
and a number of devices connected to the hub. In this situation,
there is no problem with connectivity of pairs of wires, as the hub
performs the change over of the pairs within the hub itself.
However, as network topologies have grown to include a number of
devices besides this traditional hub and spoke type of
interconnection, then device-device connectivity (where neither of
the devices are hubs) can be problematic to the operation of the
energy and power management system. Oftentimes a cross-over
connection is inserted, for example in the case of Ethernet, to
accommodate the fact that the send and receive paths differ in this
context compared to a device-hub connection context.
[0006] Further limitations and disadvantages of conventional and
traditional systems will become apparent to one of skill in the art
through comparison of such systems with the invention as set forth
in the remainder of the present application with reference to the
drawings.
SUMMARY OF THE INVENTION
[0007] The present invention provides, for the first time, a
solution that is operable in conjunction with automatic media
dependent interface crossover (MDIX). Auto MDIX is commonly
referred to in Ethernet related technology. Prior art technologies
inherently relied upon definitive knowledge about which wire pair
is the receive pair in order to perform proper energy management.
The present invention significantly increases the usefulness of an
auto power down circuitry, as it may now be used in conjunction
with auto MDIX.
[0008] Single wire, wire pair, and other connectivity schemes may
all benefit from various aspects of the present invention. As link
pulses are sent along wires, to determine connectivity within the
system, the energy associated with the link pulse is suppressed in
performing auto power down operation and energy management.
[0009] The present invention is operable to perform proper function
of any energy detect and power down circuitry without having any
knowledge of which pair is the transmit pair and which pair is the
receive pair. From certain perspectives, the present invention
considers energy detection information from both the transmit and
receive wire pairs. Then, the present invention is operable to
determine the presence of a link partner regardless of whether the
wiring was installed properly or not.
[0010] Part of an auto power down method, performed in accordance
with certain aspects of the present invention, involves
periodically transmitting link pulses on one of the transceiver's
wire pairs in order to potentially awaken the link partner. This
operation may be performed sequentially across a number of the wire
pairs as well. Then, an auto power down select circuitry is
operable to cease monitoring of the wire pair on which the link
pulses are sent; this is to ensure that a false detection of energy
is not made by the device's own generated link pulse. From certain
perspectives, the energy that is associated with link pulse that is
transmitted may be subtracted, actually or logically, from the
circuitry that performs the energy management. Various embodiments
are described below that perform the proper handling operation of
the energy that is associated with a transmitted link pulse on one
or more wire pairs.
[0011] The above-referenced description of the summary of the
invention captures some, but not all, of the various aspects of the
present invention. The claims are directed to some other of the
various other embodiments of the subject matter towards which the
present invention is directed. In addition, other aspects,
advantages and novel features of the invention will become apparent
from the following detailed description of the invention when
considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A better understanding of the invention can be obtained when
the following detailed description of various exemplary embodiments
is considered in conjunction with the following drawings.
[0013] FIG. 1 is a system diagram illustrating an embodiment of an
energy detect with auto pair select system that is built in
accordance with certain aspects of the present invention.
[0014] FIG. 2 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system that is built in
accordance with certain aspects of the present invention.
[0015] FIG. 3 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system that is built in
accordance with certain aspects of the present invention.
[0016] FIG. 4 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system that is built in
accordance with certain aspects of the present invention.
[0017] FIG. 5 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system that is built in
accordance with certain aspects of the present invention.
[0018] FIG. 6 is a state diagram illustrating an embodiment of
operation of an energy detect with auto pair select state machine
that is performed in accordance with certain aspects of the present
invention.
[0019] FIG. 7 is a functional block diagram illustrating an
embodiment of an energy detect with auto pair select method that is
performed in accordance with certain aspects of the present
invention.
[0020] FIG. 8 is a functional block diagram illustrating another
embodiment of an energy detect with auto pair select method that is
performed in accordance with certain aspects of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In various embodiments of the present invention, the
terminology of pairs is used. Those persons having skill in the art
will appreciate that single wire connectivity is also included
within the scope and spirit of the invention. The pair embodiment
will be understood by those persons having skill in the art, given
the large number of commercial types of wires that employ pair
wires, twisted pairs, and so on. However, the present invention is
also operable within embodiments that employ single wire
connectivity throughout.
[0022] An energy detect circuitry, that is operable to perform auto
power down, monitors an attached wire. This energy detect circuitry
determines if any incoming signal, or any energy, is present on the
wire that will signal that a link partner is attached to the other
end of the wire. When there is no wire attached to the other end,
or no link partner attached to the other end of a wire connected to
a device, then no energy will be present on the wire, and the
energy detect circuitry (the detector) will indicate this
condition. A state machine, that is also described in various
embodiments, is operable to recognize various forms of
transmission. One application area is the Ethernet context. The
state machine can specifically recognize 10Base-T link pulses,
10Base-T packets, 100Base-T link, and auto-negotiation link pulse
bursts.
[0023] The present invention is at least one operable within
systems that employ Ethernet based media dependent interface
crossover (MDIX). Previous systems experienced difficulty when this
additional functionality was introduced. An auto MDIX solution
automatically compensated for any improperly installed cable
pair(s). The auto MDIX solution is introduced to allow proper
functionality even when cable has not been installed properly, and
there is the undesirable crossover of wires. Ethernet employs
certain conventions to ensure that the receive and transmit wire
pair(s) are not swapped when the cable is installed in a particular
site. Prior art energy detect/power down circuitry relied solely
upon energy being detected on the receive wire pair(s). The auto
MDIX functionality is implemented into a number of transceivers.
The present invention performs an elegant modification to ensure
proper functionality of any energy detect/power down circuitry even
when auto MDIX is implemented.
[0024] From certain perspectives, a new element is added to a
transceiver-operable device. The device may be a chip, a board
having discrete components or chip-sets, or any other device having
logic and operational configure-ability. The present invention is
adaptable within BCM5411 and BCM5421 transceiver chips designed by
Broadcom Corporation. The present invention is operable to perform
proper function of any energy detect and power down circuitry
without having any knowledge of which pair is the transmit pair and
which pair is the receive pair. From certain perspectives, the
present invention considers energy detection information from both
the transmit and receive wire pairs. Then, the present invention is
operable to determine the presence of a link partner regardless of
whether the wiring was installed properly or not.
[0025] This new element, added to the transceiver-operable device,
is sometimes referred to an energy detect with auto pair select.
When a transceiver is trying to determine if there is a link
partner attached, then the present invention is operable to perform
monitoring of all of the wire pairs that are connected to the
transceiver. This is particularly helpful when auto MDIX is
employed, and there is no knowledge of the connectivity of the
pairs. Here, with no knowledge of which is the transmit pair and
which is the receive pair, then the present invention is operable
to monitor both pairs.
[0026] Part of an auto power down method, performed in accordance
with certain aspects of the present invention, involves
periodically transmitting link pulses on one of the transceiver's
wire pairs in order to potentially awaken the link partner. This
operation may be performed sequentially across a number of the wire
pairs as well. Then, an auto power down select circuitry is
operable to cease monitoring of the wire pair on which the link
pulses are sent; this is to ensure that a false detection of energy
is not made by the device's own generated link pulse. From certain
perspectives, the energy that is associated with a link pulse that
is transmitted may be subtracted, actually or logically, from the
circuitry that performs the energy management. Various embodiments
are described below that perform the proper handling operation of
the energy that is associated with a transmitted link pulse on one
or more wire pairs.
[0027] The present invention provides, for the first time, a
solution that is operable in conjunction with auto MDIX. Prior art
technologies inherently relied upon definitive knowledge about
which wire pair is the receive pair in order to perform proper
energy management. The present invention significantly increases
the usefulness of an auto power down circuitry, as it may now be
used in conjunction with auto MDIX.
[0028] FIG. 1 is a system diagram illustrating an embodiment of an
energy detect with auto pair select system 100 that is built in
accordance with certain aspects of the present invention. A device
110 and a device 120 are communicatively coupled via an n pair
interconnect 130. The n pair interconnect 130 includes an
indefinite number of pairs shown as a pair #1 131, . . . , and a
pair #n 139. The device 110 includes an energy detect circuitry
112, a state machine (logic circuitry) 114 and a power down/energy
saving circuitry 116. The functionality offered by the power
down/energy saving circuitry 116 is sometimes referred to as auto
power down functionality in various embodiments. The pair energies
of at least one of the pairs within the n pair interconnect 130 is
provided to the energy detect circuitry 112. Then, based on the
energy information of the pairs that are provided to the energy
detect circuitry 112, the state machine 114 identifies the
connectivity of the devices that are connected to the device 110.
When no device is connected to the device 110, the power
down/energy saving circuitry 116 is operable to perform the auto
powering down of the device 110 to conserve energy.
[0029] The device 120 need not necessarily have the same circuitry
and need not necessarily be operable to perform the same
functionality as the device 110. That is to say, even if the device
120 is not able to perform such energy savings/energy power down
functionality, it will not impede such functionality on the device
110. Certain aspects of the present invention are operable to be
backward compatible, from certain perspectives, into systems that
have a number of devices that are incapable of performing the
energy detect with auto pair select functionality. In addition,
devices within the network may also be upgraded to include the
functionality offered by certain aspects of the present invention
without entering any deleterious effects into other of the devices
within the network.
[0030] FIG. 2 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system 200 that is built
in accordance with certain aspects of the present invention. A
device 210 is operable to perform the functionality of energy
detect with auto pair selection 212. The present invention is
capable to perform this functionality without requiring any `a
priori` knowledge of the receive and transmit pairs 214.
[0031] For example, the device 210 is operable when connected to
one or more of a nonenergized device 220, to an energized device
230, or even when there is a pair that is connected to no device at
all. The pairs are shown as twisted pairs in this illustration. If
desired, auto MDIX functionality may be performed along one or more
of the pairs communicatively coupled to the device 210. In
addition, one or more of the device to which the device 210 is
communicatively coupled may also perform auto MDIX.
[0032] When the device 210 is communicatively coupled to an
energized device, such as the energized device 230, then the device
210 will recognize this and will remain powered up for full
operation. Then, if the energized device 230 ever becomes
non-energized, the device 210 will recognize this event and will
move into an auto power down sequence. There may also be situations
where a pair is connected to the device 210, but no other device is
communicatively coupled to the other end of the pair. Here, the
device 210 will be operable to determine that no other device is
there, and will perform auto power down functionality
thereafter.
[0033] It is also noted that the present invention is operable to
perform within systems and networks where other of the devices
within these networks and systems may or may not employ auto MDIX
functionality. As mentioned above, the present invention offers a
degree of backward compatibility here.
[0034] FIG. 3 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system 300 that is built
in accordance with certain aspects of the present invention. The
energy of an indefinite number of pairs, shown as energy pair 1, .
. . , and energy pair n is fed to an energy summing circuitry 310.
From the energy summing circuitry 310, a total energy of the
pair(s) is provided to a transmit energy subtraction circuitry 320.
It is noted that the present invention is operable to perform this
functionality within systems where only a single wire pair is used,
as well as an indefinite number of wire pairs as well. Here, in the
energy subtraction circuitry 320, a link pulse energy subtraction
circuitry 322 subtracts the transmitted link energy. A qualified
energy of the pair(s) is provided from the energy subtraction
circuitry 320 to a state machine (logic circuitry) 330. The state
machine (logic circuitry) 330 determines knowledge of the
connectivity of the system.
[0035] FIG. 4 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system 400 that is built
in accordance with certain aspects of the present invention. The
raw energy signals, that may be produced by sets of comparators in
an analog front end of a transceiver, are first combined together
using an OR gate. Any number of energy pairs may be combined in the
OR gate. Then, the output of the OR gate is fed to an AND gate,
where it is combined with a logical signal associated with the
energy being transmitted via a link pulse. The result is such that
it is suppressed during and some period after the transceiver
transmits a link pulse. A qualified energy signal is then fed to a
remaining portion of the auto power down circuitry. A state machine
414, employing logic circuitry, is operable to provide information
regarding the connectivity of the system.
[0036] FIG. 5 is a system diagram illustrating another embodiment
of an energy detect with auto pair select system 500 that is built
in accordance with certain aspects of the present invention. An
energy detect with auto pair select device 510 is communicatively
coupled to any number of other devices via twisted pair(s). The
other devices are shown as device #1 521, . . . , and device #n
529. The energy detect with auto pair select device 510 is operable
to perform energy detect with auto pair select functionality 512,
as well as auto MDIX functionality 521, and auto power down
functionality 522. The energy detect with auto pair select
functionality 512 enables the energy detect with auto pair select
device 510 to perform the auto MDIX functionality 521 and the auto
power down functionality 522 to operate in conjunction. Within
prior art systems, any auto MDIX functionality necessitated
definitive knowledge of the connectivity of the wire pairs. Here,
the energy detect with auto pair select functionality 512, as
offered by the present invention, enables the proper functionality
of the system.
[0037] FIG. 6 is a state diagram illustrating an embodiment of
operation of an energy detect with auto pair select state machine
600 that is performed in accordance with certain aspects of the
present invention. A device that operates using the energy detect
with auto pair select state machine 600 may begin initially in a
standby state or in an awake state. For illustration, the situation
where the device is in the standby state is used.
[0038] When the device is in the standby state, the device waits
until a qualified energy has been detected. As described above, the
qualified energy includes suppressing the energy associated with a
transmitted link pulse. After the qualified energy has been
detected, then the state of the energy detect with auto pair select
state machine 600 moves to an energy detect state. Then, the energy
detect with auto pair select state machine 600 waits a period of
time, shown as timeout. This timeout period may be programmed,
predetermined, or adaptive based on the operation of the device and
the network in which the device is installed. If no more energy is
received during the timeout period, then the state of the energy
detect with auto pair select state machine 600 reverts back to the
standby state.
[0039] However, if energy is received and the qualified energy is
still high after that timeout period, then the state of the energy
detect with auto pair select state machine 600 waits a period of
time shown as timer to ensure that the qualified energy is at a
high level. This again, of course, involves suppressing the energy
associated with any transmitted link pulse during evaluation of the
qualified energy. If the qualified energy is still high indicating
that link pulses are still coming in, then the state of the energy
detect with auto pair select state machine 600 changes to an awake
state. Here, the device that employs the energy detect with auto
pair select state machine 600 will remain indefinitely until there
is some indication that a link to another active device is lost.
For example, when it is detected that there is no more qualified
energy for a period of time (delta time), then the state of the
energy detect with auto pair select state machine 600 will move to
a no energy state for the length of period of a timer. The timer
length here may be different from the timer length associated with
the energy detect state. Again, the length of this timer may be
programmed, predetermined, or adaptive. This timer period may be
2-4 micro-seconds in one embodiment. Then, if the timer has passed
indicating that there is no qualified energy, the state of the
energy detect with auto pair select state machine 600 will pass
back to the standby state, thereby permitting energy savings once
again.
[0040] One differentiating factor of the present invention, among
others, when compared to any prior art system is the ability to
utilize both transmit and receive pairs of a transceiver to be
provided as inputs to a state machine such as the energy detect
with auto pair select state machine 600.
[0041] Any of the values of timeout, timers, and other parameters
within the operation of the energy detect with auto pair select
state machine 600 may be programmed, predetermined, or adaptive.
Those persons having skill in the art will appreciate that the
particular values used for these types of operational parameters
may be altered without departing from the scope and spirit of the
invention.
[0042] FIG. 7 is a functional block diagram illustrating an
embodiment of an energy detect with auto pair select method 700
that is performed in accordance with certain aspects of the present
invention. In a block 710, energy detect is performed on one or
more twisted pairs. This may involve performing energy detect on
both the transmit and receive wire pairs, as shown in a block 712.
Then, in a block 720, auto negotiation is performed. Auto
negotiation is understood by those persons having skill in the art,
and it involves sending and receiving link pulses to determine the
capability of other devices in a network that are interconnected.
For example, there is a handshaking procedure in which the various
devices may agree on a data communication rate at which both or
more devices are capable of communicating with each other. The
period associated with auto negotiation is commonly on the order of
several micro-seconds. It is noted that the energy detect with auto
pair select, as described and performed in various embodiments, may
be performed before the auto negotiation procedure, as it is
important to determine at that time if there is in fact a partner
to communicate with. During the operation within the block 720,
auto MDIX may be performed on one or more twisted pairs, as
necessary, as shown in a block 722.
[0043] Subsequently, in a block 730, the device is powered down
when there is no energy detected. When appropriate, this energy is
a qualified energy, accounting for and suppressing the energy that
is associated with any transmitted link pulses. In addition and
alternatively, in a block 740, the device is subsequently awakened
(powered up) when energy is later detected.
[0044] From certain perspectives, certain aspects of the energy
detect with auto pair select method 700 may be performed and
described by the operation of a state machine that implements and
performs the method described within the FIG. 7.
[0045] FIG. 8 is a functional block diagram illustrating another
embodiment of an energy detect with auto pair select method 800
that is performed in accordance with certain aspects of the present
invention. In a block 810, energy is sensed on one or more twisted
pairs. If desired, link pulses are simultaneously transmitted as
shown in a block 812. Then, in a block 820, the transmit link pulse
energies are subtracted from the summed energy to generate a
qualified energy. This is performed when a link pulse is sent,
regardless of whether or not a valid link has already been
achieved. In this situation, the sensed energy is transformed into
a qualified energy where the energy associated with the transmitted
link pulse is suppressed. This suppression may be performed
logically or actually, in various embodiments without departing
from the scope and spirit of the invention.
[0046] Subsequently, in a block 830, the analysis of the operating
state is determined using the qualified energy. In a block 840,
after there is knowledge of the connectivity and state of operation
of the device (knowledge of any other link partner), auto
negotiation can be performed if desired. Auto MDIX may be performed
on one or more twisted pair groups during auto negotiation, as
necessary. Ultimately, the device is powered down when there is no
qualified energy detected, as shown in a block 850. Alternatively,
a partial power down may be performed on the device where some, but
not all, of the functional components of the device are powered
down to achieve power savings as shown in a block 852.
[0047] In view of the above detailed description of the invention
and associated drawings, other modifications and variations will
now become apparent to those skilled in the art. It should also be
apparent that such other modifications and variations may be
effected without departing from the spirit and scope of the
invention.
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