U.S. patent application number 16/030251 was filed with the patent office on 2020-01-09 for device and method for fan speed control.
The applicant listed for this patent is QUANTA COMPUTER INC.. Invention is credited to Yung-Fu LI.
Application Number | 20200011339 16/030251 |
Document ID | / |
Family ID | 63914907 |
Filed Date | 2020-01-09 |
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United States Patent
Application |
20200011339 |
Kind Code |
A1 |
LI; Yung-Fu |
January 9, 2020 |
DEVICE AND METHOD FOR FAN SPEED CONTROL
Abstract
The present disclosure describes devices and methods that
include a heartbeat signal for detecting an abnormality in the
control of a fan for an electronic system. A fan controller can
assume control of a fan over a fan speed control circuit in
response to the abnormality. Control of the fan by the fan
controller can eliminate or reduce overheating within the system
caused by improper fan speed, in response to the abnormality.
Inventors: |
LI; Yung-Fu; (Taoyuan City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUANTA COMPUTER INC. |
Taoyuan City |
|
TW |
|
|
Family ID: |
63914907 |
Appl. No.: |
16/030251 |
Filed: |
July 9, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 1/20 20130101; F04D
27/001 20130101; F04D 27/004 20130101; G06F 1/206 20130101 |
International
Class: |
F04D 27/00 20060101
F04D027/00 |
Claims
1. A method of controlling a fan within an electronic system,
comprising: monitoring a heartbeat signal indicating normal
operation of the electronic system; detecting a discrepancy in the
heartbeat signal; and controlling the fan according to a safe fan
speed in response to the discrepancy.
2. The method of claim 1, wherein the heartbeat signal is generated
by a fan speed control circuit of the electronic system, and the
heartbeat signal indicates normal operation of the fan speed
control circuit.
3. The method of claim 2, wherein the electronic system is a
computer system, and the fan speed control circuit is a baseboard
management controller.
4. The method of claim 2, further comprising setting the safe fan
speed by the fan speed control circuit prior to detecting the
discrepancy.
5. The method of claim 4, wherein the safe fan speed is less than
full speed.
6. The method of claim 4, wherein the safe fan speed is set at
startup of the computer system, at reset of the computer system, or
both.
7. The method of claim 1, wherein the heartbeat signal is periodic,
and the discrepancy is a lack of the heartbeat signal during at
least one period, during two or more sequential periods, or during
two or more non-sequential periods.
8. The method of claim 1, wherein the heartbeat signal is embedded
within a fan speed control signal or separate from the fan speed
control signal.
9. The method of claim 1, further comprising: determining that the
discrepancy in the heartbeat signal has not been corrected and
continuing the controlling of the fan according to the safe fan
speed, in response to the determination.
10. An electronic system comprising: a fan speed control circuit
configured to generate a heartbeat signal indicating normal
operation of the fan speed control circuit; and a fan module
comprising a fan controller and a fan, the fan controller being
configured to detect a discrepancy in the heartbeat signal and
control the fan according to a safe fan speed, in response to the
discrepancy.
11. The electronic system of claim 10, wherein the electronic
system is a computer system, and the fan speed control circuit is a
baseboard management controller.
12. The electronic system of claim 11, wherein the baseboard
management controller is configured to set the safe fan speed prior
to the fan controller detecting the discrepancy.
13. The electronic system of claim 12, wherein the safe fan speed
is less than full speed.
14. The electronic system of claim 12, wherein the safe fan speed
is set at startup of the computer system, at reset of the computer
system, or both.
15. The electronic system of claim 10, wherein the heartbeat signal
is periodic, and the discrepancy is a lack of the heartbeat signal
during at least one period, during two or more sequential periods,
or during two or more non-sequential periods.
16. A method of controlling a fan module for cooling a computer
system, comprising: generating, by a fan speed control circuit of
the computer system, a fan speed control signal based on one or
more parameters corresponding to heat generated within the computer
system; generating, by the fan speed control circuit, a heartbeat
signal indicating normal operation of the fan speed control
circuit; controlling, by a fan controller of the fan module, a
speed of a fan of the fan module based on the fan speed control
signal; monitoring, by the fan controller, the heartbeat signal;
detecting, by the fan controller, a discrepancy in the heartbeat
signal based on the monitoring; and controlling, by the fan
controller, the speed of the fan based on a safe fan speed in place
of the fan speed control signal in response to the discrepancy.
17. The method of claim 16, further comprising: determining, by the
fan controller, that the discrepancy in the heartbeat signal has
not been corrected; and continuing, by the fan controller, the
controlling of the fan according to the safe fan speed in response
to the determination.
18. The method of claim 16, further comprising: determining, by the
fan controller, that the discrepancy in the heartbeat signal has
been corrected; and resuming, by the fan controller, controlling of
the fan according to the fan speed control signal, in response to
the determination.
19. The method of claim 16, further comprising setting the safe fan
speed, by the fan speed control circuit, prior to the fan
controller detecting the discrepancy.
20. The method of claim 16, wherein the safe fan speed is full
speed.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to cooling fans, and more
specifically, to the control of a cooling fan in response to the
lack of a control signal.
BACKGROUND
[0002] Fans are often required in various electronic systems that
generate heat to cool the systems. The speed of the fan typically
is controlled by a fan speed control circuit. For example, in
computer systems, such as server systems, there often is a
baseboard management controller (BMC) that generates a fan speed
control signal. The fan speed control signal is then sent to a fan
controller within a fan module. The fan controller dynamically
controls the fan speed based on the fan speed control signal to
cool the computer system, in addition to saving power consumption
and reducing noise.
[0003] In the event that the hardware, firmware, or software of the
fan speed control circuit fails (for example, in the BMC), the fan
may stop altogether, or keep running at a constant speed that is
insufficient for cooling the electronic system. This can lead to
the electronic system hanging due to overheating. In a worst case
scenario, improper fan speed control can even lead to permanent
damage to the system.
[0004] Accordingly, there is a need for devices and methods that
overcome the foregoing drawbacks.
SUMMARY
[0005] The various embodiments concern devices and methods for
controlling a fan in the event of an abnormality in the normal
control of the fan.
[0006] The various embodiments further concern a heartbeat signal
that is monitored by a fan controller. In the event of a
discrepancy in the heartbeat signal, the fan controller assumes
control over the fan.
[0007] A method of controlling a fan within an electronic system,
according to a first embodiment, includes monitoring a heartbeat
signal. The heartbeat signal indicates the normal operation of the
electronic system. The method further includes detecting a
discrepancy in the heartbeat signal based on the monitoring. The
method also includes controlling the fan according to a safe fan
speed in response to the discrepancy.
[0008] In some implementations, the heartbeat signal can be
generated by a fan speed control circuit of the electronic system.
In which case, the heartbeat signal indicates normal operation of
the fan speed control circuit.
[0009] In some implementations, the electronic system can be a
computer system, and the fan speed control circuit can be a
baseboard management controller.
[0010] In some implementations, the method can also include setting
the safe fan speed by the fan speed control circuit prior to
detecting the discrepancy.
[0011] In some implementations, the safe fan speed can be less than
full speed, or can be full speed.
[0012] In some implementations, the safe fan speed can be set at
startup of the computer system, at reset of the computer system, or
both.
[0013] In some implementations, the heartbeat signal can be
periodic; and the discrepancy can be a lack of the heartbeat signal
during at least one period, during two or more sequential periods,
or during two or more non-sequential periods.
[0014] In some implementations, the heartbeat signal can be
embedded within a fan speed control signal.
[0015] In some implementations, the method can include determining
that the discrepancy in the heartbeat signal has not been
corrected, and continuing the controlling of the fan according to
the safe fan speed in response to the determination.
[0016] A method of controlling a fan module for cooling a computer
system, according to a second embodiment, includes a fan speed
control circuit of the computer system generating a fan speed
control signal that is based on one or more parameters
corresponding to heat generated within the computer system. The
method further includes the fan speed control circuit generating a
heartbeat signal indicating normal operation of the fan speed
control circuit. The method also includes a fan controller of the
fan module controlling a speed of a fan of the fan module based on
the fan speed control signal. The method additionally includes the
fan controller monitoring the heartbeat signal. The method also
includes the fan controller detecting a discrepancy in the
heartbeat signal based on the monitoring. The method further
includes the fan controller controlling the speed of the fan based
on a safe fan speed, in place of the fan speed control signal in
response to the discrepancy.
[0017] In some implementations, the method includes the fan
controller determining that the discrepancy in the heartbeat signal
has not been corrected; and the fan controller continuing the
controlling of the fan according to the safe fan speed in response
to the determination.
[0018] In some implementations, the method includes the fan
controller determining that the discrepancy in the heartbeat signal
has been corrected; and the fan controller resuming control of the
fan according to the fan speed control signal in response to the
determination.
[0019] In some implementations, the method includes setting the
safe fan speed, by the fan speed control circuit, prior to the fan
controller detecting the discrepancy.
[0020] In some implementations, the safe fan speed is full
speed.
[0021] An electronic system, according to the third embodiment,
includes a fan speed control circuit configured to generate a
heartbeat signal indicating normal operation of the fan speed
control circuit. The system also includes a fan module having a fan
controller and a fan. The fan controller is configured to detect a
discrepancy in the heartbeat signal, and control the fan according
to a safe fan speed in response to the discrepancy.
[0022] In some implementations, the electronic system can be a
computer system, and the fan speed control circuit can be a
baseboard management controller. The baseboard management
controller can be configured to set the safe fan speed prior to the
fan controller detecting the discrepancy. The safe fan speed is
less than full speed. Further, the safe fan speed can be set at
startup of the computer system, at reset of the computer system, or
both.
[0023] In some implementations, the heartbeat signal can be
periodic; and the discrepancy can be a lack of the heartbeat signal
during at least one period, during two or more sequential periods,
or during two or more non-sequential periods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The disclosure, and its advantages and drawings, will be
better understood from the following description of exemplary
embodiments together with reference to the accompanying drawings.
These drawings depict only exemplary embodiments, and are therefore
not to be considered as limitations on the scope of the various
embodiments or claims.
[0025] FIG. 1 illustrates a schematic view of an electronic system
for controlling a fan module with a heartbeat signal, according to
aspects of the present disclosure.
[0026] FIG. 2 illustrates a process for controlling a fan module
within an electronic system, according to aspects of the present
disclosure.
[0027] FIG. 3 illustrates a process for setting a safe fan speed,
according to aspects of the present disclosure.
[0028] FIG. 4 illustrates a process for controlling a fan module
for cooling a computer system, according to aspects of the present
disclosure.
DETAILED DESCRIPTION
[0029] The various embodiments are described with reference to the
attached figures, where like reference numerals are used throughout
the figures to designate similar or equivalent elements. The
figures are not drawn to scale, and they are provided merely to
illustrate the instant invention. It should be understood that
numerous specific details, relationships, and methods are set forth
to provide a full understanding. One having ordinary skill in the
relevant art, however, will readily recognize that the various
embodiments can be practiced without one or more of the specific
details, or with other methods. In other instances, well-known
structures or operations are not shown in detail to avoid obscuring
certain aspects of the various embodiments. The various embodiments
are not limited by the illustrated ordering of acts or events, as
some acts may occur in different orders and/or concurrently with
other acts or events.
[0030] To that extent, elements and limitations that are disclosed,
for example, in the Abstract, Summary, and Detailed Description
sections, but not explicitly set forth in the claims, should not be
incorporated into the claims, singly, or collectively, by
implication, inference, or otherwise. For purposes of the present
detailed description, unless specifically disclaimed, the singular
includes the plural and vice versa. The word "including" means
"including without limitation." Moreover, words of approximation,
such as "about," "almost," "substantially," "approximately," and
the like, can be used herein to mean "at," "near," or "nearly at,"
or "within 3-5% of," or "within acceptable manufacturing
tolerances," or any logical combination thereof, for example.
[0031] The present disclosure describes devices and methods that
include a heartbeat signal generated by a fan speed control
circuit. The heartbeat signal is monitored by a fan controller
within a fan module. When the fan controller detects that the
heartbeat signal has stopped, or detects any other type of
discrepancy indicating an abnormality, the fan controller takes
over control of the fan speed. Specifically, the fan controller
operates the fan at a safe fan speed to keep the system associated
with the fan cool despite the abnormality.
[0032] FIG. 1 illustrates a schematic view of an electronic system
100 for controlling a fan module 102 with a heartbeat signal,
according to aspects of the present disclosure. Although the
present disclosure is primarily directed to computer systems, such
as server systems, the electronic system 100 can be within any type
of system that generates heat during use and that uses a fan to
dissipate the heat. Moreover, the electronic system 100 of FIG. 1
can be for the entire system. For example, the electronic system
100 can be an overall server system, and the fan 108 (described
below) can be for cooling the overall system. Alternatively, the
electronic system 100 of FIG. 1 can be a component electronic
system within a larger system. For example, the electronic system
100 can be a power unit, a graphics processing component, a central
processing component, or the like within a computer system; and the
fan 108 (described below) can be for cooling the specific
component.
[0033] The electronic system 100 includes the fan module 102 and a
fan speed control circuit 104. The fan module 102 includes a fan
controller 106 and a fan 108. The fan speed control circuit 104 is
separate from the fan module 102. In the context of computer
systems, the fan speed control circuit 104 can be located on the
motherboard. The fan speed control circuit 104 has access to and
monitors one or more parameters of the electronic system 100. The
parameters relate to the heat that is generated within the
electronic system 100. From the parameters, the fan speed control
circuit 104 determines the amount of cooling needed for the system
100. Based on the amount of cooling needed, the fan speed control
circuit 104 generates a fan speed control signal. In the context of
a server system, the fan speed control circuit can be a BMC. The
BMC monitors parameters of the server system that relate to how
much heat is being generated, and translates that information into
the generated fan speed control signal. For example, the parameters
can be processor, memory, and/or internal chassis temperatures. The
fan speed control circuit 104 can generate the fan speed control
signal based on hardware, firmware, software, or a combination
thereof. The fan speed control signal can be any type of digital or
analog signal. In one or more embodiments, the fan speed control
signal can be a pulse width modulation signal.
[0034] The fan speed control circuit 104 is communicatively
connected to the fan controller 106 of the fan module 102 via a
connection 110. The connection 110 can be one or more wired
connections, one or more wireless connections, or one or more wired
and wireless connections. The fan speed control circuit 104
communicates the fan speed control signal to the fan controller 106
via the connection 110. In response to the fan speed control
signal, the fan controller 106 operates the fan 108 at the
instructed speed.
[0035] In one or more embodiments, the fan controller 106 can
generate a fan operation signal and communicate the fan operation
signal back to the fan speed control circuit 104. The fan operation
signal can verify that the fan 108 is operating as instructed by
the fan speed control circuit 104. In one or more embodiments, the
fan operation signal can be a tachometer signal that reports the
number of revolutions of the fan. Based on the number of
revolutions, the fan speed control circuit 104 can verify that the
fan 108 is operating at the appropriate speed or duty cycle.
[0036] According to the present disclosure, the fan speed control
circuit 104 also generates a heartbeat signal and transmits the
heartbeat signal to the fan controller 106. The heartbeat signal
indicates normal operation of the fan speed control circuit. The
fan controller 106 can then monitor for the heartbeat signal to
determine whether there is any abnormality with the fan speed
control circuit 104, or any other component of the electronic
system 100 that may be affecting the fan speed control circuit 104.
The heartbeat signal can be a continuous or periodic signal. In one
or more embodiments, the heartbeat signal can be transmitted
(embedded) within the fan speed control signal or can be
transmitted as a separate signal. In one or more embodiments, the
heartbeat signal can be transmitted over the same wired and/or
wireless connection as the fan speed control signal and/or fan
operation signal. Alternatively, the heartbeat signal can be
transmitted over a different wired or wireless connection than the
fan speed control signal and the tachometer signal.
[0037] For example, in one embodiment, the connection 110 can be a
five-pin general purpose output pin connection. Two of the five
pins can provide a common ground and a voltage supply (e.g., a
nominal+12 Volts) to the fan module 102. The third pin can provide
the fan speed control signal to the fan controller 106. The fourth
pin can provide the fan operation signal from the fan controller
106 back to the fan speed control circuit 104. The fifth pin can be
added to provide the heartbeat signal from the fan speed control
circuit 104 to the fan controller 106.
[0038] However, in one or more embodiments, the connection 110 can
vary from being a five-pin connection. For example, the connection
110 can be a four-pin connection, and the heartbeat signal can be
provided via one of the other four pins. In one embodiment, the
heartbeat signal can be a specific, periodic pulse-width modulation
within the fan speed control signal that does not affect the speed
of the fan; or negligibly affects the speed of the fan. For
example, the specific, periodic pulse-width modulation can be a
short positive (or negative) square wave immediately followed by a
short negative (or positive) square wave that occurs according to a
specific period. In which case, the two waves effectively negate
each other with respect to changing the speed of the fan. However,
the fan controller 106 can monitor for the specific, periodic
pulse-width modulation within the fan speed control signal as the
heartbeat signal. In such embodiments, a conventional connection
between the fan speed control circuit 104 and the fan controller
106 can be used without having to add a fifth pin. However, other
types of connections for the connection 110 are possible than those
described above. Such other connections include, for example, a
platform environment control interface (PECI) bus, an
inter-integrated circuit (I.sup.2C) bus, and the like. In the case
of the PECI bus and the I.sup.2C bus, the safe fan speed signal can
be a command sent from the fan speed control circuit 104 to the fan
controller 106.
[0039] The generation and transmittal of the heartbeat signal from
the fan speed control circuit 104 to the fan controller 106
indicates that the electronic system 100 is operating normally with
respect to control of the fan 108. Accordingly, the fan controller
106 within the fan module 102 monitors for a discrepancy in the
heartbeat signal. A discrepancy can be the lack of the continuous
heartbeat signal, the lack of the heartbeat signal during one
period, or the lack of the heartbeat signal during two or more
sequential or non-sequential periods.
[0040] When the fan controller 106 detects a discrepancy in the
heartbeat signal, the fan controller 106 takes over control of the
speed of the fan 108 from the fan speed control circuit 104. When
the fan controller 106 takes over control of the fan 108, the fan
controller 106 can operate the fan 108 at a safe fan speed. In one
or more embodiments, the safe fan speed can be full speed to
provide maximum cooling. In one or more embodiments, the safe fan
speed can less than full speed. In one or more embodiments, the
safe fan speed can be a default speed set within logic of the fan
controller 106 that cannot be changed. Alternatively, in one or
more embodiments, the safe fan speed can be set by the fan speed
control circuit 104 any time before the discrepancy, such as at
startup or reset of the fan speed control circuit 104 or the
electronic system 100. The fan speed control circuit 104 can send
the safe fan speed via the heartbeat signal, the fan speed control
signal, or any other signal during operation. Thus, in the event of
an issue with the fan speed control circuit 104 controlling the fan
108 through the fan controller 106, the heartbeat signal can
prevent or reduce the likelihood of the electronic system 100
hanging or being damaged as a result of improper fan speed control.
Instead, the fan controller 106 can assume control of the fan speed
to maintain cooling within the system 100.
[0041] FIG. 2 illustrates a process 200 for controlling a fan
within an electronic system, according to aspects of the present
disclosure. The process 200 can be performed by the fan speed
control circuit 104 and the fan controller 106 disclosed above
(FIG. 1). The electronic system can be any electronic system, such
as the electronic system 100, including a computer system, a
sub-component within a computer system, or any other electronic
system that uses a fan to dissipate generated heat. The process 200
begins at step 202, where a fan controller of a fan module monitors
for a heartbeat signal. During normal operation, a fan speed
control circuit that monitors parameters that correspond to the
amount of heat generated by the electronic system generates the
heartbeat signal. The heartbeat signal indicates normal operation
of the electronic system. In one or more embodiments, normal
operation of the electronic system includes the fan speed control
circuit receiving the expected parameters used to generate a fan
speed control signal. In one or more embodiments, normal operation
also includes values of the parameters being within expected and/or
predetermined ranges, such as normal operating conditions. Normal
operation also includes the fan speed control circuit generating
and outputting the fan speed control signal to the fan controller
according to a predetermined scheme, such as continuously or
periodically. The fan module can be associated with the cooling of
any electronic system, such as a computer system or a component
within a computer system. The heartbeat signal can be continuous or
periodic. In one or more embodiments, the heartbeat signal can be a
high/low toggling signal, a command/data signal, or a combination
thereof.
[0042] At step 204, the fan controller of the fan module determines
whether a discrepancy exists in the heartbeat signal. The
discrepancy can be the lack of the fan speed control signal. For
example, with a continuous fan speed control signal, the
discrepancy can be the fan controller no longer receiving the
signal. As another example, with a periodic fan speed control
signal, the discrepancy can be the fan controller not receiving the
signal for one period, or not receiving the signal for two or more
sequential or non-sequential periods. As another example, for a
toggling signal and/or a command data signal, the discrepancy can
be an incorrect value within the signal. If a discrepancy does not
exist, the process 200 loops back to step 202. If a discrepancy
exists, the fan controller of the fan module detects a discrepancy
in the heartbeat signal based on the monitoring, and the process
200 proceeds to step 206.
[0043] At step 206, in response to the fan controller detecting a
discrepancy, the fan controller controls the fan according to a
safe fan speed. The safe fan speed is configured to keep the fan
operating at a speed that attempts to maintain the cooling of the
electronic system, despite the lack of proper fan speed control by
the fan speed control circuit. In one or more embodiments, the safe
fan speed can be a maximum operating speed of the fan (i.e., full
speed). In one or more embodiments, the safe fan speed can be less
than the maximum operating speed but still a sufficient amount
that, on average, should minimize the buildup of heat within the
electronic system. For example, in one embodiment, the safe fan
speed can be determined based on a worst case thermal simulation
(e.g., CPU and memory running at full load), but still be less than
full speed. In one embodiment, the safe fan speed can be
pre-defined and fixed by thermal or system designer. The safe fan
speed can be a default speed set within logic of the fan
controller. Alternatively, the safe fan speed can be set by the fan
speed control circuit prior to the discrepancy, as discussed
further with respect to the process 300 below. For example, the
safe fan speed can be the maximum speed which the fan speed control
circuit sends to fan controller during normal system operation. The
fan controller can record all fan speed requirements from the fan
speed control circuit, and then update and keep the maximum speed
as the safe fan speed.
[0044] In one or embodiments, the process 200 ends after step 206,
and the fan controller controls the fan according to the safe fan
speed indefinitely, or until power is cut from the fan module, the
electronic system, or a combination thereof. In one or more
embodiments, the process 200 optionally can proceed to step 208
where the fan controller determines whether the discrepancy in the
heartbeat signal has been corrected. If the discrepancy has been
corrected, the process 200 loops back to step 202, and the fan
controller continues monitoring the heartbeat signal. If the
discrepancy has not been corrected, the process 200 loops back to
step 206, and the fan controller continues operating the fan
according to the safe fan speed.
[0045] Based on the process 200, the heartbeat signal can prevent
or reduce the likelihood of the electronic system hanging or being
damaged as a result of improper fan speed control in the event of
an issue with the fan speed control circuit. The fan controller can
detect a discrepancy in the control of the fan speed via the
heartbeat signal and take over control from the fan speed control
circuit. The fan controller assuming control can reduce the
likelihood of issues within the electronic system, in response to
the buildup of heat.
[0046] In one or more embodiments, the fan controller can perform
one or more additional or alternative functions in response to
detecting a discrepancy in the heartbeat signal. The one or more
functions aid in preventing the system from hanging, or being
damaged, in response to the fan speed control circuit not being
able to control the speed of the fan.
[0047] In one embodiment, the fan module can include an audible
and/or electronic alarm that is triggered when the fan controller
detects a discrepancy in the heartbeat signal. An alarm can alert
an operator, technician, or the like, of the discrepancy. In
response, the operator, technician, or the like can investigate the
issue and take appropriate action, such as shutting the system down
and/or manually controlling the fan speed using a switch or other
manual control device within the fan module.
[0048] In one embodiment, the fan controller can be communicatively
coupled to a circuit within the system that allows the fan
controller to initiate shutdown of the system. The fan controller
shutting the system down further prevents damage to the system
caused by the inability to control the fan speed. In one
embodiment, the fan controller can communicate to one or more CPUs
within the system to reduce the clock speeds of the CPUs to reduce
the amount of heat that is generated. In one embodiment, the fan
controller can be communicatively coupled to a circuit within the
system that allows the fan controller to signal or control the
system or other key components (e.g., memory modules (e.g., dual
in-line memory modules or DIMMs), a network interface controller
(NIC), a storage module, or other components) to slow down or
reduce heat.
[0049] FIG. 3 illustrates a process 300 for setting a safe fan
speed within an electronic system, according to aspects of the
present disclosure. The process begins at step 302, where the fan
speed control circuit starts or resets, and begins generating and
transmitting the fan speed control signal to the fan module. As
described above, the fan speed control circuit monitors parameters
of the electronic system associated with heat generation to
generate the fan speed control signal. Step 302 can occur when the
electronic system, such as the computer system, that includes the
fan speed control circuit starts and/or resets.
[0050] At step 304, the fan speed control circuit sends the safe
fan speed to the fan module. In one or more embodiments, the fan
speed control circuit can send the safe fan speed to the fan module
via a heartbeat signal, such as the heartbeat signal described in
the process 200. In one or more embodiments, the fan speed control
circuit can send the safe fan speed via another signal, such as the
fan speed control signal. The fan speed control circuit can send
the safe fan speed once at startup or after a reset, periodically
or on demand, in response to a software, firmware, or hardware
request. Thereafter, the fan module will have the safe fan speed
stored in logic in the event of a discrepancy in the heartbeat
signal. The process 300 can occur before the process 200 has
initiated or simultaneously with the process 200, once the fan
module and the fan speed control circuit startup.
[0051] FIG. 4 illustrates a process 400 for controlling a fan
module for cooling a computer system, according to aspects of the
present disclosure. The process 400 can be performed by the fan
speed control circuit 104 and the fan controller 106 disclosed
above (FIG. 1). The process 400 begins at step 402, when the fan
speed control circuit of the computer system generates a fan speed
control signal based on one or more parameters corresponding to
heat generated within the computer system. As discussed above, the
parameters can relate to, for example, one or more processor
temperatures, one or more memory chip temperatures, one or more
ambient temperatures within the computer system, or any other
temperature associated with the computer system. The parameters can
also relate to the amount of power consumed by the computer system,
such as by the one or more processors, one or more memory chips,
one or more power units, and the like.
[0052] At step 404, the fan speed control circuit generates a
heartbeat signal. As discussed above, the heartbeat signal
indicates normal operation of the fan speed control circuit.
[0053] In one embodiment, the process 400 can include step 405,
where the fan speed control circuit generates a safe fan speed and
transmits the safe fan speed to the fan controller, such as within
the heartbeat signal. Alternatively, the fan speed control circuit
can transmit the safe fan speed with the fan speed control signal
or another signal. Further, although described in relation to step
404, the fan speed control circuit can generate and transmit the
safe fan speed to the fan controller at any step or time prior to
the step 410, such as when the fan speed control circuit starts or
resets.
[0054] At step 406, the fan controller of the fan module controls
the speed of the fan module based on the fan speed control signal
generated and transmitted by the fan speed control circuit. The fan
speed control circuit 104 can transmit the fan speed control signal
to the fan controller via the connection 110, as described above.
For example, the connection 110 can include a general purpose
output pin, and the fan speed control circuit 104 can transmit the
fan speed control signal via pulse-width modulation over the
general purpose output in.
[0055] At step 408, the fan controller monitors the heartbeat
signal generated and transmitted by the fan speed control circuit.
The fan speed control circuit 104 can transmit the heartbeat signal
to the fan controller via the connection 110, as described above.
For example, the heartbeat signal can be transmitted over the same
general purpose output pin as the fan speed control signal. In
which case, the heartbeat signal can be embedded within the fan
speed control signal. Alternatively, the fan speed control circuit
can transmit the heartbeat signal over a separate general purpose
output pin of the connection, or any other connection disclosed
herein.
[0056] At step 410, the fan controller detects a discrepancy in the
heartbeat signal based on the monitoring. The discrepancy can be
the lack of the heartbeat signal, or any other variation in the
heartbeat signal that indicates an abnormality (or potential
abnormality) of the fan speed control circuit. For example, the
discrepancy can be the lack of a periodic heartbeat signal for one
period, or for more than two sequential or non-sequential periods.
The discrepancy can be any other discrepancy disclosed above.
[0057] At step 412, the fan controller controls the speed of the
fan based on a safe fan speed, in place of the fan speed control
signal in response to the discrepancy. As disclosed above, the safe
fan speed can be full speed for maximum cooling. Alternatively, the
safe fan speed can be less than full speed. In one or more
embodiments, the safe fan speed can be set in the logic of the fan
controller; or can be set based on the fan controller having
previously received the safe fan speed from the fan speed control
circuit prior to the discrepancy.
[0058] At step 414, the fan controller can optionally determine
whether the discrepancy in the heartbeat signal has been corrected.
The fan controller can perform the determination continuously,
periodically, or on demand, such as in response to a software,
firmware, or hardware request. If the fan controller determines
that the discrepancy in the heartbeat signal has been corrected,
the process can loop back to step 408. If the fan controller
determines that the discrepancy in the heartbeat signal has not
been corrected, the process can loop back to step 412.
[0059] Based on the process 400, the computer system can control
the fan module for cooling of the system. Further, in the event of
an abnormality of the normal control, the lack of the heartbeat
signal can prevent or reduce the likelihood of the computer system
hanging or damaging one or more components as a result of improper
fan speed and temperature control.
[0060] While various embodiments of the present invention have been
described above, it should be understood that they have been
presented by way of example only, and not limitation. Numerous
changes to the disclosed embodiments can be made in accordance with
the disclosure herein without departing from the spirit or scope.
Thus, the breadth and scope of the present invention should not be
limited by any of the above described embodiments. Rather, the
scope of the invention should be defined in accordance with the
following claims and their equivalents.
[0061] Although the invention has been illustrated and described
with respect to one or more implementations, equivalent alterations
and modifications will occur to others skilled in the art upon the
reading and understanding of this specification and the annexed
drawings. In addition, while a particular feature of the invention
may have been disclosed with respect to only one of several
implementations, such feature may be combined with one or more
other features of the other implementations as may be desired and
advantageous for any given or particular application.
[0062] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting. As
used herein, the singular forms "a", "an," and "the" are intended
to include the plural forms as well, unless the context clearly
indicates otherwise. Furthermore, to the extent that the terms
"including", "includes", "having", "has", "with", or variants
thereof are used in either the detailed description and/or the
claims, such terms are intended to be inclusive in a manner similar
to the term "comprising."
[0063] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. Furthermore, terms, such as those defined in
commonly used dictionaries, should be interpreted as having a
meaning that is consistent with their meaning in the context of the
relevant art and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
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