U.S. patent application number 16/255278 was filed with the patent office on 2019-05-23 for semiconductor device and power feed system.
The applicant listed for this patent is RENESAS ELECTRONICS CORPORATION. Invention is credited to Takefumi ENDO.
Application Number | 20190157863 16/255278 |
Document ID | / |
Family ID | 59387145 |
Filed Date | 2019-05-23 |
![](/patent/app/20190157863/US20190157863A1-20190523-D00000.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00001.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00002.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00003.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00004.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00005.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00006.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00007.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00008.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00009.png)
![](/patent/app/20190157863/US20190157863A1-20190523-D00010.png)
View All Diagrams
United States Patent
Application |
20190157863 |
Kind Code |
A1 |
ENDO; Takefumi |
May 23, 2019 |
SEMICONDUCTOR DEVICE AND POWER FEED SYSTEM
Abstract
A semiconductor device includes a power supply circuit which
generates an output voltage to be supplied to a USB device
connected to a USB connector, a sensing circuit which senses an
output voltage or an output state of the power supply circuit, a
control circuit which controls the power supply circuit, and a
register which stores an output set voltage value associated with
the power supply circuit or various types of information. The
control circuit outputs a notification signal based on a result of
sensing by the sensing circuit to the outside.
Inventors: |
ENDO; Takefumi; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RENESAS ELECTRONICS CORPORATION |
Tokyo |
|
JP |
|
|
Family ID: |
59387145 |
Appl. No.: |
16/255278 |
Filed: |
January 23, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15417991 |
Jan 27, 2017 |
10230235 |
|
|
16255278 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02H 3/202 20130101;
H02J 7/00034 20200101; H02J 7/00 20130101; H02H 5/047 20130101;
H02J 1/10 20130101; H02J 1/00 20130101 |
International
Class: |
H02J 1/00 20060101
H02J001/00; H02H 5/04 20060101 H02H005/04; H02H 3/20 20060101
H02H003/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 2016 |
JP |
2016-014660 |
Jan 28, 2016 |
JP |
2016-014671 |
Sep 28, 2016 |
JP |
2016-189574 |
Claims
1. A semiconductor device comprising: a power supply circuit which
generates an output voltage to be supplied to a USB device
connected to a USB connector; a sensing circuit which senses the
output voltage or an output state of the power supply circuit; a
control circuit which controls the power supply circuit; and a
register which stores an output set voltage value associated with
the power supply circuit or various types of information, the
control circuit outputting a notification signal based on a result
of sensing by the sensing circuit to outside.
2. The semiconductor device according to claim 1, wherein the
control circuit has the register store the output set voltage value
associated with the power supply circuit or information on a state
of the power supply circuit based on the result of sensing by the
sensing circuit.
3. The semiconductor device according to claim 2, wherein the
control circuit has the register store the output set voltage value
based on a setting command from the outside.
4. The semiconductor device according to claim 2, wherein the
sensing circuit includes a temperature abnormal condition
determination circuit which determines whether a temperature of the
power supply circuit is normal, and the control circuit has the
register store information on the output state of the power supply
circuit based on a result of determination by the temperature
abnormal condition determination circuit.
5. The semiconductor device according to claim 2, wherein the
sensing circuit includes a voltage abnormal condition determination
circuit which determines whether a voltage of the power supply
circuit is normal, and the control circuit has the register store
information on the state of the power supply circuit based on a
result of determination by the voltage abnormal condition
determination circuit.
6. A semiconductor device comprising: a power supply unit which
generates an output voltage to be supplied to a USB device
connected to a USB connector; and a control unit which controls the
power supply unit, the power supply unit including a power supply
circuit, a sensing circuit which senses an output voltage or an
output state of the power supply circuit, a power supply control
circuit which controls the power supply circuit, and a register
which stores an output set voltage value associated with the power
supply circuit or various types of information, the power supply
control circuit having the register store the output set voltage
value of the power supply circuit or information on a state of the
power supply circuit based on a result of sensing by the sensing
circuit, and the control unit performing a prescribed operation
based on the output set voltage value of the power supply circuit
or the information on the state of the power supply circuit stored
in the register.
7. The semiconductor device according to claim 6, wherein the power
supply control circuit outputs a notification signal to the control
unit in response to the result of sensing by the sensing circuit,
and the control unit issues a request to the power supply control
circuit for information on the state of the power supply circuit
stored in the register based on the notification signal from the
power supply control circuit.
8. The semiconductor device according to claim 6, wherein the
sensing circuit includes a temperature abnormal condition
determination circuit which determines whether a temperature of the
power supply circuit is normal, and the power supply control
circuit has the register store information indicating that the
temperature of the power supply circuit is abnormal when the
temperature of the power supply circuit is abnormal as a result of
determination by the temperature abnormal condition determination
circuit.
9. The semiconductor device according to claim 8, wherein the power
supply control circuit has the register store information
indicating that the temperature of the power supply circuit is
normal when the temperature of the power supply circuit is normal
as a result of determination by the temperature abnormal condition
determination circuit, and the control unit performs a recovery
operation based on information on a state of the temperature of the
power supply circuit stored in the register.
10. The semiconductor device according to claim 6, wherein the
sensing circuit includes a voltage abnormal condition determination
circuit which determines whether a voltage of the power supply
circuit exceeds a reference value, and the power supply control
circuit has the register store information indicating that a
voltage state of the power supply circuit is abnormal when a
voltage of the power supply circuit is abnormal based on a result
of determination by the voltage abnormal condition determination
circuit.
11. The semiconductor device according to claim 10, wherein the
control unit instructs the power supply control circuit to perform
a reset operation to initialize an operation of the power supply
unit based on the information indicating that the voltage state of
the power supply circuit is abnormal stored in the register.
12. The semiconductor device according to claim 11, wherein the
control unit counts the number of times of the reset operation
performed, and when the number of times of the reset operation
performed is equal to or more than a prescribed number of times,
the control unit stops an operation to reset the power supply
unit.
13. A power feed system which feeds power to a USB device connected
to a USB connector, the power feed system comprising: a control
unit which obtains information on an output voltage which can
variably be set for driving the USB device by communicating with
the USB device; and a power supply unit which generates an output
voltage to be supplied to the USB device based on the obtained
information on the output voltage, the power supply unit including
a power supply circuit, a sensing circuit which senses an output
voltage or an output state of the power supply circuit, a power
supply control circuit which controls the power supply circuit, and
a register which stores information on the power supply circuit,
the power supply control circuit outputting a notification signal
based on a result of sensing by the sensing circuit to outside.
Description
RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. Ser. No.
15/417,991, filed on Jan. 27, 2017, which claims the benefit of
Japanese Patent Applications No. 2016-014671, filed on Jan. 28,
2016, Japanese Patent Applications No. 2016-014660, filed on Jan.
28, 2016 and Japanese Patent Applications No. 2016-189574, filed on
Sep. 28, 2016, the entire contents of each are hereby incorporated
by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present disclosure relates to a power supply circuit
which generates an output voltage to be supplied to a universal
serial bus (USB) device.
Description of the Background Art
[0003] A configuration in which electric power is supplied to a USB
device through a USB connector (also referred to as USB power feed)
has conventionally been known (Japanese Patent Laying-Open No.
2012-123673).
SUMMARY OF THE INVENTION
[0004] An output voltage supplied to a conventional USB device has
been fixed (by way of example, 5 V).
[0005] Equipment having a USB connector has recently increased and
each piece of equipment is expected to be fed power through a
USB.
[0006] In this connection, since requested electric power is
different for each piece of equipment, an output voltage on a power
feed side is not fixed but should be variable, and various
protection functions are provided to ensure safety of power feed at
a high voltage.
[0007] In case of a failure, there has been no means for holding a
state of the failure and it has not been possible to perform an
operation appropriate in accordance with a state.
[0008] The present disclosure was made to solve the problems above,
and an object is to provide a semiconductor device and a power feed
system which can perform an operation appropriate in accordance
with a state of a power supply circuit.
[0009] Other objects and novel features will become apparent from
the description herein and the accompanying drawings.
[0010] According to one example, a semiconductor device includes a
power supply circuit which generates an output voltage to be
supplied to a USB device connected to a USB connector, a sensing
circuit which senses the output voltage or an output state of the
power supply circuit, a control circuit which controls the power
supply circuit, and a register which stores an output set voltage
value associated with the power supply circuit or various types of
information. The control circuit outputs a notification signal
based on a result of sensing by the sensing circuit to the
outside.
[0011] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a diagram illustrating a configuration of a power
supply control system 1 based on a first embodiment.
[0013] FIG. 2 is a diagram illustrating a configuration of a power
feed device 10 based on the first embodiment.
[0014] FIG. 3 is a diagram illustrating a configuration of a
protection circuit 22 based on the first embodiment.
[0015] FIG. 4 is a sequence diagram when a voltage level is
regulated from an old voltage to a new voltage in power supply
control system 1 based on the first embodiment.
[0016] FIG. 5 is a sequence diagram for illustrating an operation
at the time of a system error in power supply control system 1
based on the first embodiment.
[0017] FIG. 6 is a sequence diagram for illustrating an operation
in power supply control system 1 based on the first embodiment when
a temperature is abnormal.
[0018] FIG. 7 is a sequence diagram for illustrating an operation
in power supply control system 1 based on the first embodiment when
a voltage is abnormal.
[0019] FIG. 8 is a flowchart when processing for regulating a
voltage level in a power delivery control unit 16 based on the
first embodiment is performed.
[0020] FIG. 9 is a flowchart illustrating an operation for
regulating a voltage in a power delivery power supply unit 14 based
on the first embodiment.
[0021] FIG. 10 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the first embodiment when a
temperature is abnormal.
[0022] FIG. 11 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the first embodiment when a
temperature is abnormal.
[0023] FIG. 12 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the first embodiment when a
voltage is abnormal.
[0024] FIG. 13 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the first embodiment when a
voltage is abnormal.
[0025] FIG. 14 is a sequence diagram for illustrating an operation
in power supply control system 1 based on a modification of the
first embodiment when a temperature is abnormal.
[0026] FIG. 15 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the modification of the
first embodiment when a temperature is abnormal.
[0027] FIG. 16 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the modification of the
first embodiment when a temperature is abnormal.
[0028] FIG. 17 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the modification of the
first embodiment when a voltage is abnormal.
[0029] FIG. 18 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the modification of the
first embodiment when a voltage is abnormal.
[0030] FIG. 19 is a diagram illustrating a configuration of power
supply control system 1 based on a second embodiment.
[0031] FIG. 20 is a diagram illustrating a configuration of a power
feed device 10# based on the second embodiment.
[0032] FIG. 21 is a diagram illustrating a configuration of a
voltage determination circuit 23 based on the second
embodiment.
[0033] FIG. 22 is a sequence diagram when a voltage level is
regulated from an old voltage to a new voltage in a power supply
control system 1# based on the second embodiment.
[0034] FIGS. 23A and 23B are diagrams illustrating an operation for
changing a voltage in a power supply circuit 20 based on the second
embodiment.
[0035] FIG. 24 is a sequence diagram illustrating an operation in
an abnormal condition in regulation of a voltage level in power
supply control system 1# based on the second embodiment.
[0036] FIG. 25 is a flowchart when processing for regulating a
voltage level in a power delivery control unit 16# based on the
second embodiment is performed.
[0037] FIG. 26 is a flowchart illustrating an operation for
regulating a voltage of a power delivery power supply unit 14#
based on the second embodiment.
[0038] FIG. 27 is a sequence diagram illustrating a normal
operation during power feed from power delivery power supply unit
14# to a power reception device 100 based on the second
embodiment.
[0039] FIG. 28 is a sequence diagram illustrating an operation when
an abnormal condition occurs during power feed from power delivery
power supply unit 14# to power reception device 100 based on the
second embodiment.
[0040] FIG. 29 is a flowchart illustrating an operation of power
delivery control unit 16# based on the second embodiment in
issuance of a timer reset command.
[0041] FIG. 30 is a flowchart illustrating an operation of power
delivery power supply unit 14# based on the second embodiment in
issuance of the timer reset command.
[0042] FIG. 31 is a diagram illustrating a configuration of a power
feed device 11 based on a third embodiment.
[0043] FIG. 32 is a flowchart when processing for regulating a
voltage level in each of power delivery control units 16#A and 16#B
based on the third embodiment is performed.
[0044] FIG. 33 is a flowchart illustrating a sub routine process
for checking a voltage request in power feed in step S4#.
[0045] FIG. 34 is a diagram illustrating a configuration of a power
feed device 11# based on a fourth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] An embodiment will be described in detail with reference to
the drawings. The same or corresponding elements in the drawings
have the same reference characters allotted and description thereof
will not be repeated.
First Embodiment
[0047] <A. Overall Configuration>
[0048] <a1. Configuration of Power Supply Control System
1>
[0049] FIG. 1 is a diagram illustrating a configuration of a power
supply control system 1 based on a first embodiment.
[0050] Referring to FIG. 1, power supply control system 1 includes
a power feed device (power feed control device) 10 and a power
reception device 100.
[0051] Power reception device 100 has a USB connector 102, a power
delivery control unit 104, a USB data control unit 106, and an
application processing unit 108.
[0052] Power feed device 10 has a USB connector 12, a power
delivery power supply v 14, a power delivery control unit 16, and a
USB data control unit 18.
[0053] USB connector 12 and USB connector 102 are connected to each
other through a USB bus 110.
[0054] USB bus 110 includes a power supply line VL, a data line DL,
and a control data line CL.
[0055] Power reception device 100 receives supply of a voltage from
power feed device 10 through power supply line VL when USB
connector 102 and USB connector 12 are connected to each other
through USB bus 110.
[0056] Power reception device 100 and power feed device 10 are
configured to be able to supply and receive data to and from each
other through data line DL when USB connector 102 and USB connector
12 are connected to each other through USB bus 110. Data is
supplied and received through data line DL between USB data control
unit 18 of power feed device 10 and USB data control unit 106 of
power reception device 100.
[0057] Power reception device 100 and power feed device 10 are
configured to be able to supply and receive control data to and
from each other through control data line CL when USB connector 102
and USB connector 12 are connected to each other through USB bus
110. Control data is supplied and received through control data
line CL between power delivery control unit 16 of power feed device
10 and power delivery control unit 104 of power reception device
100.
[0058] Power delivery control unit 16 controls power delivery power
supply unit 14. Specifically, power delivery control unit 16
indicates setting of a level of a voltage to be supplied to power
delivery power supply unit 14. In the present example, power
delivery power supply unit 14 is a power supply device which can
variably regulate a level of a voltage to be supplied to the
outside upon receiving input of an alternating current (AC) voltage
or a direct current (DC) voltage as a power supply input. By way of
example, a voltage level can be regulated in a range from 5 V to 20
V. Power delivery control unit 16 communicates with power reception
device 100 through control data line CL and controls power delivery
power supply unit 14 based on voltage data from power reception
device 100.
[0059] Power delivery control unit 104 has electric power necessary
for each unit supplied, upon receiving supply of a voltage from
power feed device 10 through power supply line VL. Power delivery
control unit 104 communicates with power delivery control unit 16
through control data line CL. Specifically, power delivery control
unit 104 transmits voltage data on a voltage necessary for power
reception device 100 to power delivery control unit 16 through
control data line CL.
[0060] USB data control unit 106 supplies and receives data to and
from USB data control unit 18 of power feed device 10 connected
through USB bus 110.
[0061] Application processing unit 108 is a unit executing a
prescribed application. As a central processing unit (CPU) executes
a program, a prescribed application is executed. USB data control
unit 106 transfers data from equipment connected through USB
connector 102 to application processing unit 108 as necessary and
transmits data from application processing unit 108 to equipment
connected through USB connector 102.
[0062] <a2. Configuration of Power Feed Device 10>
[0063] FIG. 2 is a diagram illustrating a configuration of power
feed device 10 based on the first embodiment.
[0064] Referring to FIG. 2, power feed device 10 includes USB
connector 12, power delivery power supply unit 14, and power
delivery control unit 16. USB data control unit 18 is not
shown.
[0065] Power delivery power supply unit 14 includes a power supply
circuit 20, a protection circuit 22, a control circuit 24, a
register 26, and an interface 28.
[0066] Power supply circuit 20 generates a power supply voltage to
be supplied to the outside, upon receiving input of an alternating
current (AC) voltage or a direct current (DC) voltage as a power
supply input. Power supply circuit 20 supplies a generated power
supply voltage to another USB device through USB connector 12
connected to power supply line VL.
[0067] Protection circuit 22 is a circuit for ensuring safety of
power delivery power supply unit 14. For example, when a junction
temperature of power supply circuit 20 increases, the circuit is
activated and notifies control circuit 24 of an abnormal condition.
Control circuit 24 instructs power supply circuit 20 to stop power
supply based on the notification.
[0068] Control circuit 24 controls entire power delivery power
supply unit 14.
[0069] Interface 28 is connected to control circuit 24. Interface
28 transmits data from control circuit 24 to power delivery control
unit 16, or receives data from power delivery control unit 16 and
transfers the data to control circuit 24.
[0070] Register 26 stores information on power delivery power
supply unit 14.
[0071] Specifically, register 26 includes a voltage setting region
26A where information on setting of a power supply voltage of power
supply circuit 20 is stored and a status storage region 26B where
information on an internal state of power supply circuit 20 is
stored.
[0072] Control circuit 24 writes data into register 26 as necessary
and reads data stored in register 26 and transmits the data to
power delivery control unit 16 through interface 28.
[0073] Power delivery control unit 16 includes an interface 30, a
communication interface 32, a microcomputer 34, and a memory
36.
[0074] Microcomputer 34 controls entire power delivery control unit
16.
[0075] Memory 36 stores various programs. Microcomputer 34 performs
a prescribed function based on a program stored in memory 36.
[0076] Interface 30 is used for supplying and receiving data to and
from power delivery power supply unit 14.
[0077] Interface 30 is connected to microcomputer 34. Interface 30
transmits data from microcomputer 34 to power delivery power supply
unit 14 or receives data from power delivery power supply unit 14
and transfers the data to microcomputer 34.
[0078] Communication interface 32 is an interface for establishing
power delivery control communication with another USB device
through USB connector 12 connected to control data line CL.
[0079] Communication interface 32 is connected to microcomputer 34.
Communication interface 32 transmits control data from
microcomputer 34 to another USB device (power reception device 100)
or receives control data from another USB device (power reception
device 100) and transfers the control data to microcomputer 34.
[0080] <a3. Configuration of Protection Circuit 22>
[0081] FIG. 3 is a diagram illustrating a configuration of
protection circuit 22 based on the first embodiment.
[0082] Referring to FIG. 3, protection circuit 22 includes a
temperature abnormal condition determination circuit 22A
determining whether or not a temperature of power supply circuit 20
is normal and a voltage abnormal condition determination circuit
22B determining whether or not a power supply voltage of power
supply circuit 20 is normal.
[0083] Temperature abnormal condition determination circuit 22A
includes a comparator 120 and a temperature detector 122.
[0084] Temperature detector 122 outputs a voltage in accordance
with a temperature.
[0085] Comparator 120 compares a voltage from temperature detector
122 with a reference value and outputs a control signal based on a
result of comparison to control circuit 24.
[0086] Temperature detector 122 is used for detecting a junction
temperature of power supply circuit 20 by way of example.
[0087] Specifically, when a voltage from temperature detector 122
has exceeded the reference value, comparator 120 outputs a control
signal (at the "H" level) indicating that fact to control circuit
24. The reference value can be set to a value ensuring safety of
power supply circuit 20.
[0088] Control circuit 24 controls on/off of an operation of power
supply circuit 20 based on a control signal from comparator 120.
Specifically, control circuit 24 stops an operation for power
supply by power supply circuit 20 in response to an input of the
control signal (at the "H" level) from comparator 120. Control
circuit 24 has an operation for power supply by power supply
circuit 20 continued when a control signal (at the "L" level) is
input from comparator 120.
[0089] Voltage abnormal condition determination circuit 22B
includes a comparator 130 and a voltage detection circuit 132.
[0090] Voltage detection circuit 132 detects a voltage from power
supply circuit 20.
[0091] Comparator 130 compares a voltage from voltage detection
circuit 132 with a reference value and outputs a control signal
based on a result of comparison to control circuit 24.
[0092] Specifically, when a voltage from voltage detection circuit
132 has exceeded the reference value, comparator 130 outputs a
control signal (at the "H" level) indicating that fact to control
circuit 24. The reference value can be set to a value ensuring
safety of power supply circuit 20.
[0093] Control circuit 24 controls on/off of an operation of power
supply circuit 20 based on a control signal from comparator 130.
Specifically, control circuit 24 stops an operation for power
supply by power supply circuit 20 in response to an input of the
control signal (at the "H" level") from comparator 130. Control
circuit 24 has an operation for power supply by power supply
circuit 20 continued when a control signal (at the "L" level) is
input from comparator 130.
[0094] <B. Voltage Control Sequence>
[0095] <b1. Regulation of Voltage Level>
[0096] FIG. 4 is a sequence diagram when a voltage level is
regulated from an old voltage to a new voltage in power supply
control system 1 based on the first embodiment.
[0097] Referring to FIG. 4, power reception device 100 which is a
consumption side issues a voltage request (sequence sq1). Power
delivery control unit 104 issues a request to power delivery
control unit 16 for a voltage necessary for power reception device
100.
[0098] Power delivery control unit 16 determines whether or not
power can be fed in response to the voltage request from power
reception device 100. It checks whether or not a requested value of
the voltage level is within a power feed allowable range. When it
is determined that the value of the requested voltage level is
within the power feed allowable range, a notification that the
voltage is permitted is given to power delivery control unit 104
(sequence sq2).
[0099] Power reception device 100 which is the consumption side
accepts permission (sequence sq3).
[0100] Power reception device 100 is thus set to a stand-by state
and waits for an instruction indicating being ready from a power
feed side.
[0101] Power delivery control unit 104 outputs a notification that
permission is accepted to power feed device 10, upon receiving the
notification that the voltage is permitted from power feed device
10 which is a supply side.
[0102] In response, power feed device 10 starts a voltage
regulation operation on a side of power feed device 10.
[0103] Power delivery control unit 16 gives a voltage instruction
to power delivery power supply unit 14 (sequence sq4).
[0104] Upon receiving the voltage instruction, power delivery power
supply unit 14 changes a voltage (sequence sq5). Control circuit 24
of power delivery power supply unit 14 has register 26 store
information on a voltage to be supplied in voltage setting region
26A.
[0105] Power feed device 10 which is the power feed side notifies
power reception device 100 which is the consumption side that a
voltage is ready after lapse of a prescribed period since power
delivery control unit 16 gives the voltage instruction to power
delivery power supply unit 14 (sequence sq6). The prescribed period
is set in advance to a period equal to or longer than a period
necessary until change to a new voltage is made from issuance of
the voltage instruction to power delivery power supply unit 14.
[0106] Power reception device 100 which is the consumption side
accepts the voltage being ready, upon receiving a notification
indicating that a voltage is ready from power feed device 10
(sequence sq7).
[0107] Power reception device 100 is thus set from the stand-by
state to a current consumption state and driven upon receiving
supply of a voltage from power feed device 10.
[0108] <b2. Case of System Error>
[0109] FIG. 5 is a sequence diagram for illustrating an operation
at the time of a system error in power supply control system 1
based on the first embodiment.
[0110] Referring to FIG. 5, when a system error (for example, a
communication error) against power reception device 100 occurs,
power feed device 10 which is the power feed side gives a hard
reset notification (sequence sq10). Power delivery control unit 16
gives a hard reset notification to power delivery control unit
104.
[0111] Power reception device 100 which is the consumption side
accepts the hard reset notification (sequence sq11). Power
reception device 100 is thus set to the stand-by state in which
supply of a voltage from power feed device 10 is awaited.
[0112] Then, power feed device 10 which is the power feed side
gives a reset instruction (sequence sq12). Power delivery control
unit 16 instructs power delivery power supply unit 14 to reset.
[0113] Power delivery power supply unit 14 changes a voltage upon
receiving a reset instruction from power delivery control unit 16
(sequence sq13). Control circuit 24 of power delivery power supply
unit 14 sets a voltage from power supply circuit 20 to 0 V upon
receiving the reset instruction.
[0114] Then, power delivery control unit 16 gives a voltage
instruction to power delivery power supply unit 14 (sequence
sq14).
[0115] Power delivery power supply unit 14 changes a voltage upon
receiving the voltage instruction (sequence sq15). Control circuit
24 of power delivery power supply unit 14 has register 26 store
information on a voltage to be supplied in voltage setting region
26A. Specifically, control circuit 24 sets an initial value in
voltage setting region 26A of register 26 as information on a
voltage to be supplied. In the present example, 5 V is set.
[0116] <b3. Case of Abnormal Temperature>
[0117] FIG. 6 is a sequence diagram for illustrating an operation
in power supply control system 1 based on the first embodiment when
a temperature is abnormal.
[0118] Referring to FIG. 6, it is assumed that a temperature is
abnormal in power delivery power supply unit 14 (sequence sq20).
Specifically, temperature abnormal condition determination circuit
22A outputs a control signal (at the "H" level") to control circuit
24 in accordance with a junction temperature of power supply
circuit 20. Control circuit 24 carries out power supply off control
of power supply circuit 20 and has power supply circuit 20 stop an
operation for power supply. Specifically, 0 V is set.
[0119] Then, in power delivery power supply unit 14, information is
written in a register (sequence sq21). Specifically, control
circuit 24 writes information on an abnormal temperature in status
storage region 26B of register 26.
[0120] Power delivery control unit 16 reads information from
register 26 (sequence sq22). Information is read in response to an
instruction from power delivery control unit 16 to power delivery
power supply unit 14 every prescribed period.
[0121] Power delivery control unit 16 obtains information from
register 26, confirms that a temperature is abnormal, and gives a
hard reset notification (sequence sq23). Power delivery control
unit 16 gives a hard reset notification to power delivery control
unit 104.
[0122] Power reception device 100 which is the consumption side
accepts the hard reset notification (sequence sq24). Power
reception device 100 is thus set to the stand-by state in which
voltage supply from power feed device 10 is awaited.
[0123] Then, it is assumed that a temperature has returned to a
normal condition in power delivery power supply unit 14 (sequence
sq25).
[0124] Then, in power delivery power supply unit 14, information is
written in register 26 (sequence sq26). Specifically, control
circuit 24 writes information on a temperature into status storage
region 26B of register 26. In the present example, a value
indicating that a junction temperature of power supply circuit 20
is normal is written.
[0125] Power delivery control unit 16 reads information from
register 26 (sequence sq27). Information is read in response to an
instruction from power delivery control unit 16 to power delivery
power supply unit 14 every prescribed period.
[0126] Power delivery control unit 16 obtains information from
register 26, confirms that a temperature is normal, and gives a
voltage instruction to power delivery power supply unit 14
(sequence sq28).
[0127] Power delivery power supply unit 14 changes a voltage upon
receiving the voltage instruction (sequence sq29). Control circuit
24 of power delivery power supply unit 14 has register 26 store
information on a voltage to be supplied in voltage setting region
26A. Specifically, control circuit 24 sets an initial value as
information on a voltage to be supplied in voltage setting region
26A of register 26. In the present example, 5 V is set.
[0128] <b4. Case of Abnormal Voltage>
[0129] FIG. 7 is a sequence diagram for illustrating an operation
in power supply control system 1 based on the first embodiment when
a voltage is abnormal.
[0130] Referring to FIG. 7, it is assumed that a voltage is
abnormal in power delivery power supply unit 14 (sequence sq30).
Specifically, voltage abnormal condition determination circuit 22B
outputs a control signal (at the "H" level) to control circuit 24
when a voltage from voltage detection circuit 132 exceeds a
reference value. Control circuit 24 carries out power supply off
control of power supply circuit 20 and has power supply circuit 20
stop an operation for power supply. Specifically, 0 V is set.
[0131] Then, in power delivery power supply unit 14, information is
written in register 26 (sequence sq31). Specifically, control
circuit 24 writes information on an abnormal voltage in status
storage region 26B of register 26.
[0132] Power delivery control unit 16 reads information from
register 26 (sequence sq32). Information is read in response to an
instruction from power delivery control unit 16 to power delivery
power supply unit 14 every prescribed period.
[0133] Power delivery control unit 16 obtains information from
register 26, confirms that a voltage is abnormal, and gives a hard
reset notification (sequence sq33). Power delivery control unit 16
gives a hard reset notification to power delivery control unit
104.
[0134] Power reception device 100 which is the consumption side
accepts the hard reset notification (sequence sq34). Power
reception device 100 is thus set to the stand-by state in which
voltage supply from power feed device 10 is awaited.
[0135] Then, power delivery control unit 16 gives a voltage
instruction to power delivery power supply unit 14 (sequence
sq35).
[0136] Power delivery power supply unit 14 changes a voltage upon
receiving the voltage instruction (sequence sq36). Control circuit
24 of power delivery power supply unit 14 has register 26 store
information on a voltage to be supplied in voltage setting region
26A. Specifically, control circuit 24 sets an initial value as
information on a voltage to be supplied in voltage setting region
26A of register 26. In the present example, 5 V is set.
[0137] Power delivery power supply unit 14 writes information in
register 26 (sequence sq37). Specifically, control circuit 24
resets information indicating an abnormal voltage stored in status
storage region 26B of register 26.
[0138] Therefore, in the case of an abnormal voltage, when an
abnormal condition is sensed, an operation for power supply by
power supply circuit 20 is stopped, however, the abnormal condition
may be temporary. Therefore, an operation for stopping an operation
for power supply and thereafter resuming an operation for supply of
a voltage is repeated.
[0139] <C. Control Flow>
[0140] <c1. Regulation of Voltage Level>
[0141] FIG. 8 is a flowchart when processing for regulating a
voltage level in power delivery control unit 16 based on the first
embodiment is performed.
[0142] Referring to FIG. 8, power delivery control unit 16
determines whether or not a voltage request has been issued from
power reception device 100 which is the consumption side (step
S2).
[0143] When a voltage request has not been issued from power
reception device 100 which is the consumption side in step S2 (NO
in step S2), power delivery control unit 16 does not have to
regulate a voltage level and a state in step S2 is maintained.
[0144] When a voltage request has been issued from power reception
device 100 which is the consumption side in step S2 (YES in step
S2), power delivery control unit 16 checks a voltage request for
power feed (step S4).
[0145] Then, power delivery control unit 16 determines whether or
not a voltage request is OK (step S6). Specifically, power delivery
control unit 16 determines whether or not power can be fed in
response to the voltage request from power reception device 100.
Whether or not a value of a requested voltage level is within a
power feed allowable range is checked.
[0146] Then, when power delivery control unit 16 determines that a
voltage request is OK (YES in step S6), it gives a notification
that a voltage is permitted (step S8). Power delivery control unit
16 notifies power delivery control unit 104 of power reception
device 100 which is the consumption side that the voltage is
permitted. Power reception device 100 is thus set to the stand-by
state and waits for an instruction indicating being ready from the
power feed side.
[0147] Then, power delivery control unit 16 determines whether or
not it has received a notification that permission is accepted
(step S9).
[0148] Power delivery control unit 16 maintains step S9 until it
receives a notification that permission is accepted, and when it
determines that it has received such a notification (YES in step
S9), it gives a voltage instruction to power delivery power supply
unit 14 (step S10). Power delivery power supply unit 14 changes a
voltage upon receiving the voltage instruction.
[0149] Then, power delivery control unit 16 determines whether or
not a prescribed period has elapsed (step S12). The prescribed
period is set in advance to a period equal to or longer than a
period necessary until change to a new voltage is made from
issuance of the voltage instruction to power delivery power supply
unit 14.
[0150] When power delivery control unit 16 determines that the
prescribed period has elapsed (YES in step S12), it notifies power
reception device 100 which is the consumption side that the voltage
is ready (step S14). Then, the process ends (end).
[0151] Thus, power reception device 100 accepts the voltage being
ready, makes transition from the stand-by state to a current
consumption state, and is driven upon receiving supply of a voltage
from power feed device 10.
[0152] When power delivery control unit 16 determines in step S6
that a voltage request is not OK (NO in step S6), it gives a
notification that a voltage is not permitted (not permitted) (step
S16).
[0153] Then, the process ends (end). In this case, requested power
supply to power reception device 100 is not started.
[0154] <c2. Operation for Regulating Voltage of Power Delivery
Power Supply Unit 14>
[0155] FIG. 9 is a flowchart illustrating an operation for
regulating a voltage in power delivery power supply unit 14 based
on the first embodiment. An operation of control circuit 24 of
power delivery power supply unit 14 will be described.
[0156] Referring to FIG. 9, control circuit 24 determines whether
or not a voltage instruction has been received from power delivery
control unit 16 (step S30).
[0157] In step S30, control circuit 24 maintains a state until a
voltage instruction is received from power delivery control unit
16, and when it receives the voltage instruction (YES in step S30),
it has register 26 store information (step S32). Specifically,
information is stored in voltage setting region 26A of register
26.
[0158] Then, control circuit 24 instructs power supply circuit 20
to output an indicated voltage (step S34). Power supply circuit 20
regulates a level of a power supply voltage generated in accordance
with the instruction from control circuit 24 until a target voltage
is attained.
[0159] Then, the process ends (end).
[0160] <c3. Operation of Power Delivery Power Supply Unit 14
when Temperature is Abnormal>
[0161] FIG. 10 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the first embodiment when a
temperature is abnormal. An operation of control circuit 24 of
power delivery power supply unit 14 will be described.
[0162] Referring to FIG. 10, control circuit 24 determines whether
or not a temperature is abnormal (step S40). Control circuit 24
determines whether or not a control signal (at the "H" level) is
input from temperature abnormal condition determination circuit
22A.
[0163] In step S40, control circuit 24 maintains a state until it
determines that a temperature is abnormal, and when it determines
that a temperature is abnormal (YES in step S40), it stops an
operation (step S42). Control circuit 24 carries out power supply
off control and instructs power supply circuit 20 to stop an
operation for power supply. Specifically, 0 V is set.
[0164] Then, control circuit 24 has register 26 store information
(step S44). Specifically, control circuit 24 has information stored
in status storage region 26B of register 26. Specifically,
information indicating that a temperature is abnormal is
stored.
[0165] Then, control circuit 24 determines whether or not a
temperature is normal (step S46). Control circuit 24 determines
whether or not a control signal (at the "L" level) is input from
temperature abnormal condition determination circuit 22A.
[0166] In step S46, control circuit 24 maintains a state until it
determines that a temperature is normal, and when it determines
that a temperature is normal (YES in step S46), it has register 26
store information (step S48). Specifically, information is stored
in status storage region 26B of register 26. Specifically,
information indicating that a temperature is normal is stored.
[0167] Then, the process returns to step S40.
[0168] <c4. Recovery Operation when Temperature is
Abnormal>
[0169] FIG. 11 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the first embodiment when a
temperature is abnormal. An operation in microcomputer 34 of power
delivery control unit 16 will mainly be described.
[0170] Referring to FIG. 11, power delivery control unit 16
determines whether or not a prescribed period has elapsed (step
S50). In the present example, power delivery control unit 16 checks
information in register 26 every prescribed period.
[0171] When power delivery control unit 16 determines that a
prescribed period has elapsed (YES in step S50), it checks register
26 (step S52). Specifically, microcomputer 34 requests information
in register 26, and checks information stored in status storage
region 26B of register information transmitted from power delivery
power supply unit 14 in response to the request.
[0172] Then, power delivery control unit 16 determines whether or
not a temperature is abnormal as information in register 26 (step
S54). Specifically, microcomputer 34 determines whether or not
there is information that a temperature is abnormal in status
storage region 26B of register 26.
[0173] Then, when power delivery control unit 16 determines in step
S54 that a temperature is abnormal (YES in step S54), it has stop
of recovery continued (step S56). In this case, microcomputer 34
does not give a voltage instruction to power delivery power supply
unit 14.
[0174] Then, the process returns to step S50 and whether or not a
prescribed period has elapsed is determined (step S50).
[0175] When power delivery control unit 16 determines in step S54
that a temperature is normal (NO in step S54), it indicates
recovery (step S58). In this case, microcomputer 34 gives a voltage
instruction to power delivery power supply unit 14. Power delivery
power supply unit 14 changes a voltage in response to the voltage
instruction and performs a recovery operation.
[0176] Then, the process ends (end).
[0177] Therefore, when a temperature has reliably become low, a
recovery operation can be performed based on information for
determining whether or not a temperature is normal stored in
register 26.
[0178] Therefore, an operation appropriate in accordance with an
abnormal condition can be performed on power supply circuit 20
based on information stored in status storage region 26B of
register 26. Safety of power supply circuit 20 can thus be
enhanced.
[0179] <c5. Operation of Power Delivery Power Supply Unit 14
when Voltage is Abnormal>
[0180] FIG. 12 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the first embodiment when a
voltage is abnormal. An operation of control circuit 24 of power
delivery power supply unit 14 will be described.
[0181] Referring to FIG. 12, control circuit 24 determines whether
or not a voltage is abnormal (step S60). Control circuit 24
determines whether or not a control signal (at the "H" level") is
input from voltage abnormal condition determination circuit
22B.
[0182] In step S60, control circuit 24 maintains a state until it
determines that a voltage is abnormal, and when it determines that
a voltage is abnormal (YES in step S60), it stops an operation
(step S62). Control circuit 24 carries out power supply off control
and instructs power supply circuit 20 to stop an operation for
power supply by power supply circuit 20. Specifically, 0 V is
set.
[0183] Then, control circuit 24 has register 26 store information
(step S64). Specifically, control circuit 24 has information stored
in status storage region 26B of register 26. Specifically,
information indicating that a voltage is abnormal is stored.
[0184] Then, the process returns to step S60.
[0185] <c6. Recovery Operation when Voltage is Abnormal>
[0186] FIG. 13 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the first embodiment when a
voltage is abnormal. An operation in microcomputer 34 of power
delivery control unit 16 will mainly be described.
[0187] Referring to FIG. 13, power delivery control unit 16
determines whether or not a prescribed period has elapsed (step
S70). In the present example, power delivery control unit 16 checks
information in register 26 every prescribed period.
[0188] When power delivery control unit 16 determines that the
prescribed period has elapsed (YES in step S70), it checks register
26 (step S72). Specifically, microcomputer 34 requests information
in register 26 and checks information stored in status storage
region 26B of register information transmitted from power delivery
power supply unit 14 in response to the request.
[0189] Then, power delivery control unit 16 determines whether or
not a voltage is abnormal as information in register 26 (step S74).
Specifically, microcomputer 34 determines whether or not there is
information that a voltage is abnormal in status storage region 26B
of register 26.
[0190] When power delivery control unit 16 determines in step S74
that a voltage is normal (NO in step S74), the process returns to
step S70.
[0191] When power delivery control unit 16 determines in step S74
that a voltage is abnormal (YES in step S74), it checks the number
of times of recovery due to an abnormal voltage (step S76). The
number of times of recovery due to the abnormal voltage is stored
in memory 36 of power delivery control unit 16. Microcomputer 34
obtains the number of times of recovery due to the abnormal voltage
stored in memory 36.
[0192] Then, power delivery control unit 16 determines whether or
not the number of times of recovery due to the abnormal voltage is
equal to or more than a prescribed number of times (step S78).
Microcomputer 34 determines whether or not the number of times of
recovery due to the abnormal voltage stored in memory 36 is equal
to or more than the prescribed number of times.
[0193] When it is determined in step S78 that the number of times
of recovery due to the abnormal voltage is less than the prescribed
number of times (NO in step S78), recovery is indicated and
register 26 is reset (step S80). Specifically, microcomputer 34
gives a voltage instruction to power delivery power supply unit 14.
Power delivery power supply unit 14 changes a voltage in response
to the voltage instruction and performs a recovery operation. An
instruction to reset information on the abnormal voltage is given
to power delivery power supply unit 14. Thus, information
indicating the abnormal voltage stored in status storage region 26B
of register 26 of power delivery power supply unit 14 is reset.
[0194] Then, power delivery control unit 16 counts up the number of
times of recovery due to the abnormal voltage (step S82).
Microcomputer 34 of power delivery control unit 16 stores a value
resulting from count-up as the number of times of recovery due to
the abnormal voltage in memory 36.
[0195] Then, the process returns to step S70.
[0196] When it is determined in step S78 that the number of times
of recovery due to the abnormal voltage is equal to or more than
the prescribed number of times (YES in step S78), recovery is
stopped (step S84).
[0197] Then, the process ends (end). Specifically, microcomputer 34
quits the process without giving a voltage instruction to power
delivery power supply unit 14. Therefore, in this case, a recovery
operation is not performed.
[0198] In the present example, when the number of times of recovery
is less than a prescribed number of times, an abnormal voltage may
merely be sporadic and hence a recovery operation is performed.
When the number of times of recovery is equal to or more than the
prescribed number of times, an abnormal voltage is not merely
sporadic but there may be another reason for a failure (such as
short-circuiting) and hence a recovery operation is not
performed.
[0199] Therefore, an operation appropriate in accordance with an
abnormal condition can be performed on power supply circuit 20
based on information stored in status storage region 26B of
register 26. Thus, safety of power supply circuit 20 can be
enhanced.
[0200] <Modification>
[0201] <b5. Another Example when Temperature is Abnormal>
[0202] FIG. 14 is a sequence diagram for illustrating an operation
in power supply control system 1 based on a modification of the
first embodiment when a temperature is abnormal. In the present
modification, a notification signal is output from power delivery
power supply unit 14 to power delivery control unit 16.
[0203] Referring to FIG. 14, it is assumed that a temperature is
abnormal in power delivery power supply unit 14 (sequence sq40).
Specifically, temperature abnormal condition determination circuit
22A outputs a control signal (at the "H" level) to control circuit
24 in accordance with a junction temperature of power supply
circuit 20. Control circuit 24 carries out power supply off control
of power supply circuit 20 and stops an operation for power supply
by power supply circuit 20. Specifically, 0 V is set.
[0204] Then, in power delivery power supply unit 14, information is
written in a register (sequence sq41). Specifically, control
circuit 24 writes information on an abnormal temperature in status
storage region 26B of register 26.
[0205] Then, power delivery power supply unit 14 performs
processing for giving a notification to power delivery control unit
16. Specifically, control circuit 24 outputs an interrupt
notification signal to power delivery control unit 16 (sequence
sq42).
[0206] Then, upon receiving the interrupt notification signal,
power delivery control unit 16 reads information from register 26
(sequence sq43). Power delivery control unit 16 issues a request to
power delivery power supply unit 14 for information in register 26
in response to the interrupt notification signal.
[0207] Power delivery control unit 16 obtains information from
register 26, confirms that a temperature is abnormal, and gives a
hard reset notification (sequence sq44). Power delivery control
unit 16 gives a hard reset notification to power delivery control
unit 104.
[0208] Power reception device 100 which is the consumption side
accepts the hard reset notification (sequence sq45). Power
reception device 100 is thus set to the stand-by state in which
supply of a voltage from power feed device 10 is awaited.
[0209] Then, it is assumed that a temperature has returned to a
normal condition in power delivery power supply unit 14 (sequence
sq46).
[0210] Then, in power delivery power supply unit 14, information is
written in register 26 (sequence sq47). Specifically, control
circuit 24 writes information on a temperature into status storage
region 26B of register 26. In the present example, a value
indicating that a junction temperature of power supply circuit 20
is normal is written.
[0211] Then, power delivery power supply unit 14 performs
processing for giving a notification to power delivery control unit
16. Specifically, control circuit 24 outputs an interrupt
notification signal to power delivery control unit 16 (sequence
sq48).
[0212] Upon receiving the interrupt notification signal, power
delivery control unit 16 reads information from register 26
(sequence sq49). Power delivery control unit 16 requests
information in register 26 of power delivery power supply unit 14
in response to the interrupt notification signal.
[0213] Power delivery control unit 16 obtains information from
register 26, confirms that a temperature is normal, and gives a
voltage instruction to power delivery power supply unit 14
(sequence sq50).
[0214] Upon receiving the voltage instruction, power delivery power
supply unit 14 changes a voltage (sequence sq51). Control circuit
24 of power delivery power supply unit 14 has register 26 store
information on a voltage to be supplied in voltage setting region
26A. Specifically, control circuit 24 sets an initial value as
information on a voltage to be supplied in voltage setting region
26A of register 26. In the present example, 5 V is set.
[0215] In the present modification, an interrupt notification
signal which notifies power delivery control unit 16 of the fact
that writing in register 26 has been performed is output in writing
in register 26 of power delivery power supply unit 14. Thus, it is
not necessary to obtain information in register 26 every prescribed
period but information in register 26 should only be obtained in
response to input of the interrupt notification signal. Therefore,
load in monitoring of information in register 26 in power delivery
control unit 16 is mitigated.
[0216] <c7. Another Operation of Power Delivery Power Supply
Unit 14 when Temperature is Abnormal>
[0217] FIG. 15 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the modification of the
first embodiment when a temperature is abnormal. An operation of
control circuit 24 of power delivery power supply unit 14 will be
described.
[0218] FIG. 15 is different from the flowchart in FIG. 10 in
addition of steps S45 and S49.
[0219] After information is stored in register 26 in step S44,
power delivery power supply unit 14 issues an interrupt signal to
power delivery control unit 16 (step S45). Specifically, control
circuit 24 outputs an interrupt notification signal to power
delivery control unit 16.
[0220] After information is stored in register 26 in step S48,
power delivery power supply unit 14 issues an interrupt signal to
power delivery control unit 16 (step S49). Specifically, control
circuit 24 outputs an interrupt notification signal to power
delivery control unit 16.
[0221] Then, the process returns to step S40. Since other portions
are the same as in the flowchart in FIG. 10, detailed description
thereof will not be repeated.
[0222] <c8. Another Recovery Operation when Temperature is
Abnormal>
[0223] FIG. 16 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the modification of the
first embodiment when a temperature is abnormal. An operation in
microcomputer 34 of power delivery control unit 16 will mainly be
described.
[0224] FIG. 16 is different from the flowchart in FIG. 11 in
replacement of step S50 with step S51.
[0225] Specifically, power delivery control unit 16 determines
whether or not an interrupt notification signal has been issued
(step S51). In the present example, microcomputer 34 of power
delivery control unit 16 determines whether or not an interrupt
notification signal has been received from power delivery power
supply unit 14.
[0226] Power delivery control unit 16 maintains a state in step S51
until an interrupt notification signal is issued, and when it
determines that the interrupt notification signal has been issued
(YES in step S51), it checks register 26 (step S52). Specifically,
microcomputer 34 requests information in register 26 and checks
information stored in status storage region 26B of register
information transmitted from power delivery power supply unit 14 in
response to the request.
[0227] Since other portions are the same as in the flowchart in
FIG. 11, detailed description thereof will not be repeated.
[0228] Though issuance of an interrupt signal when a temperature is
abnormal has been described above, it can also similarly be
applicable to an abnormal voltage.
[0229] <c9. Another Operation of Power Delivery Power Supply
Unit 14 when Voltage is Abnormal>
[0230] FIG. 17 is a flowchart illustrating an operation of power
delivery power supply unit 14 based on the modification of the
first embodiment when a voltage is abnormal. An operation of
control circuit 24 of power delivery power supply unit 14 will be
described.
[0231] FIG. 17 is different from the flowchart in FIG. 12 in
addition of step S65.
[0232] After information is stored in register 26 in step S64,
control circuit 24 issues an interrupt signal to power delivery
control unit 16 (step S65). Specifically, control circuit 24
outputs an interrupt notification signal to power delivery control
unit 16.
[0233] Then, the process returns to step S60. Since other portions
are the same as in the flowchart in FIG. 12, detailed description
thereof will not be repeated.
[0234] <c10. Another Recovery Operation when Voltage is
Abnormal>
[0235] FIG. 18 is a flowchart illustrating a recovery operation of
power delivery control unit 16 based on the modification of the
first embodiment when a voltage is abnormal. An operation in
microcomputer 34 of power delivery control unit 16 will mainly be
described.
[0236] FIG. 18 is different from the flowchart in FIG. 13 in
replacement of step S70 with step S71.
[0237] Specifically, power delivery control unit 16 determines
whether or not an interrupt notification signal has been issued
(step S71). In the present example, microcomputer 34 of power
delivery control unit 16 determines whether or not an interrupt
notification signal has been received from power delivery power
supply unit 14.
[0238] Power delivery control unit 16 maintains a state in step S71
until an interrupt notification signal is issued, and when it
determines that the interrupt notification signal has been issued
(YES in step S71), it checks register 26 (step S72). Specifically,
microcomputer 34 requests information in register 26 and checks
information stored in status storage region 26B of register
information transmitted from power delivery power supply unit 14 in
response to the request.
[0239] Since other portions are the same as in the flowchart in
FIG. 13, detailed description thereof will not be repeated.
[0240] In the present modification, an interrupt notification
signal which notifies power delivery control unit 16 that writing
in register 26 has been performed is output in writing in register
26 of power delivery power supply unit 14. Thus, it is not
necessary to obtain information in register 26 every prescribed
period but information in register 26 should only be obtained in
response to input of the interrupt notification signal. Therefore,
load in monitoring of information in register 26 in power delivery
control unit 16 is mitigated.
[0241] <Other Forms>
[0242] Though a configuration in power reception device 100 in
which supply of a power supply voltage is received from power feed
device 10 has been described, power reception device 100 can also
include power delivery power supply unit 14 as in power feed device
10. Power reception device 100 can also have a function as power
feed device 10 and can also be configured to supply a power supply
voltage to yet another USB device.
Second Embodiment
[0243] A scheme capable of ensuring safety of power feed at a high
voltage will now be described.
[0244] <a4. Configuration of Power Supply Control System
1#>
[0245] FIG. 19 is a diagram illustrating a configuration of power
supply control system 1# based on a second embodiment.
[0246] Referring to FIG. 19, a power supply control system 1#
includes a power feed device (power feed control device) 10# and
power reception device 100.
[0247] Replacement of power feed device 10 with power feed device
10# is different from the configuration in FIG. 1. Since the
configuration is otherwise similar, detailed description thereof
will not be repeated.
[0248] Power feed device 10# is different from power feed device 10
in that power delivery power supply unit 14 is replaced with a
power delivery power supply unit 14# and power delivery control
unit 16 is replaced with a power delivery control unit 16#. Since
the configuration is otherwise the same as described with reference
to FIG. 1, detailed description thereof will not be repeated.
[0249] <a5. Configuration of Power Feed Device 10#>
[0250] FIG. 20 is a diagram illustrating a configuration of power
feed device 10# based on the second embodiment.
[0251] Referring to FIG. 20, power feed device 10# includes USB
connector 12, power delivery power supply unit 14#, and power
delivery control unit 16#. USB data control unit 18 is omitted.
[0252] Power delivery power supply unit 14# includes power supply
circuit 20, a voltage determination circuit 23, control circuit 24,
a timer 25, a register 27, and interface 28.
[0253] Power delivery power supply unit 14# is different from power
delivery power supply unit 14 in that voltage determination circuit
23 is provided instead of protection circuit 22, register 27 is
provided instead of register 26, and timer 25 is further provided.
Since the configuration is otherwise similar, detailed description
thereof will not be repeated.
[0254] Voltage determination circuit 23 determines whether or not a
value of a voltage regulated by power supply circuit 20 has
attained to a set voltage. Voltage determination circuit 23 outputs
a result of determination to control circuit 24. When control
circuit 24 determines that a value of the voltage regulated by
power supply circuit 20 has attained to the set voltage based on a
result of determination by voltage determination circuit 23, it
outputs a notification signal to external power delivery control
unit 16#.
[0255] Control circuit 24 controls entire power delivery power
supply unit 14#.
[0256] Register 27 stores information on power delivery power
supply unit 14#.
[0257] Specifically, register 27 stores information on setting of a
power supply voltage of power supply circuit 20.
[0258] Control circuit 24 writes data in register 27 as
necessary.
[0259] Timer 25 has a time counting function and counts time in
response to an instruction from control circuit 24.
[0260] Power delivery control unit 16# includes interface 30,
communication interface 32, microcomputer 34, a timer 35, and
memory 36.
[0261] Power delivery control unit 16# is different from power
delivery control unit 16 in further including timer 35. Since the
configuration is otherwise the same as in power delivery control
unit 16, detailed description thereof will not be repeated.
[0262] Timer 35 has a time counting function and counts time in
response to an instruction from microcomputer 34.
[0263] <a6. Configuration of Voltage Determination Circuit
23>
[0264] FIG. 21 is a diagram illustrating a configuration of voltage
determination circuit 23 based on the second embodiment.
[0265] Referring to FIG. 21, voltage determination circuit 23
includes a determination unit 200.
[0266] Specifically, determination unit 200 compares an output
voltage regulated by power supply circuit 20 with a reference
value, and determines whether or not the output voltage regulated
by power supply circuit 20 has attained to (reached) the reference
value. The reference value is calculated based on information on
setting of the power supply voltage of power supply circuit 20
stored in register 27.
[0267] Whether or not the output voltage regulated by power supply
circuit 20 has attained to (reached) the reference value includes
not only an example where the voltage is the same as the reference
value but also an example where the voltage is in the vicinity of
the reference value. Specifically, it is determined that the
reference value has been reached when a difference between a
voltage value and the reference value is within a prescribed
range.
[0268] Determination unit 200 compares an output voltage regulated
by power supply circuit 20 with the reference value, and when it
determines that the output voltage regulated by power supply
circuit 20 has attained to (reached) the reference value, it
outputs that determination to control circuit 24.
[0269] Control circuit 24 outputs a notification signal to power
delivery control unit 16# based on a result of determination by
determination unit 200.
[0270] Power delivery control unit 16# notifies power delivery
control unit 104 that the voltage is ready. Power reception device
100 starts consumption of a current upon receiving the
notification.
[0271] <b5. Regulation of Voltage Level>
[0272] FIG. 22 is a sequence diagram when a voltage level is
regulated from an old voltage to a new voltage in power supply
control system 1# based on the second embodiment.
[0273] Referring to FIG. 22, power reception device 100 which is
the consumption side issues a voltage request (sequence sq1). Power
delivery control unit 104 issues a request to power delivery
control unit 16# for a voltage necessary for power reception device
100.
[0274] Power delivery control unit 16# determines whether or not
power can be fed in response to the voltage request from power
reception device 100. The power delivery control unit checks
whether or not a value of a requested voltage level is within a
power feed allowable range. When it is determined that the value of
the requested voltage level is within the power feed allowable
range, a notification that the voltage is permitted is given to
power delivery control unit 104 (sequence sq2).
[0275] Power reception device 100 which is the consumption side
accepts permission (sequence sq3).
[0276] Power reception device 100 is thus set to the stand-by state
and waits for an instruction indicating being ready from the power
feed side.
[0277] Power delivery control unit 104 outputs a notification that
permission is accepted to power feed device 10# upon receiving the
notification that the voltage is permitted from power feed device
10# which is the supply side.
[0278] Upon receiving the notification, power feed device 10#
starts an operation to regulate a voltage on the side of power feed
device 10# (sequence sq61).
[0279] Power delivery control unit 16# transmits voltage
information to power delivery power supply unit 14# through
interface 30 and interface 28. Control circuit 24 of power delivery
power supply unit 14# has register 27 store information on a
voltage to be supplied (sequence sq62).
[0280] Control circuit 24 of power delivery power supply unit 14#
instructs power supply circuit 20 to output a voltage based on
information on the voltage set in register 27. Thus, the output
voltage is changed from the old voltage to a new voltage (sequence
sq63).
[0281] Then, when voltage determination circuit 23 determines that
the indicated voltage has attained to (reached) the reference value
in power supply circuit 20, it outputs that determination to
control circuit 24. When control circuit 24 determines that the
indicated voltage has attained to (reached) the reference value in
power supply circuit 20, it gives a notification signal to power
delivery control unit 16# (sequence sq64).
[0282] Power delivery control unit 16# determines whether or not a
notification signal from power delivery power supply unit 14# has
been received after lapse of a prescribed period since transmission
of voltage information to power delivery power supply unit 14#, and
when the notification signal has been received, it notifies power
reception device 100 which is the consumption side that the voltage
is ready (sequence sq65). The prescribed period is set in advance
to a period equal to or longer than a period necessary until change
to a new voltage is made from transmission of voltage information
to power delivery power supply unit 14#.
[0283] Power reception device 100 which is the consumption side
accepts the voltage being ready upon receiving the notification
that the voltage is ready from power feed device 10# (sequence
sq66).
[0284] Thus, power reception device 100 is set from the stand-by
state to the current consumption state and driven upon receiving
supply of a voltage from power feed device 10#.
[0285] In the present scheme, power delivery control unit 16#
determines whether or not it has received a notification signal
from power delivery power supply unit 14# after lapse of a
prescribed period since transmission of voltage information to
power delivery power supply unit 14#, and when it has received the
notification signal, it notifies power reception device 100 which
is the consumption side that a voltage is ready. Therefore, since
power is fed after change to a new voltage has been confirmed,
safety of power feed by the power feed device can be enhanced.
[0286] FIGS. 23A and 23B are diagrams illustrating an operation for
changing a voltage in power supply circuit 20 based on the second
embodiment.
[0287] As shown in FIG. 23A, in response to an instruction to
change a voltage at time T1, a voltage increases from an initial
voltage and is regulated in the vicinity of a set voltage.
[0288] At time T2, when a difference between the voltage regulated
by power supply circuit 20 and a target set voltage is within a
prescribed range, a notification signal is output.
[0289] At time T3, timing of lapse of a prescribed period since
issuance of the instruction to change a voltage is shown. Power
delivery control unit 16# determines whether or not it has received
a notification signal from power delivery power supply unit 14#
after lapse of a prescribed period since transmission of voltage
information to power delivery power supply unit 14#, and when it
has received the notification signal, it notifies power reception
device 100 which is the consumption side that a voltage is
ready.
[0290] As shown in FIG. 23B, in accordance with an instruction to
change a voltage at time T4, a voltage lowers from an initial
voltage and is regulated in the vicinity of a set voltage.
[0291] At time T5, when a difference between the voltage regulated
by power supply circuit 20 and the target set voltage is within a
prescribed range, a notification signal is output.
[0292] At time T6, timing of lapse of a prescribed period since
issuance of the instruction to change a voltage is shown. Power
delivery control unit 16# determines whether or not it has received
a notification signal from power delivery power supply unit 14#
after lapse of a prescribed period since transmission of voltage
information to power delivery power supply unit 14#, and when it
has received the notification signal, it notifies power reception
device 100 which is the consumption side that a voltage is
ready.
[0293] <b6. In Case of Abnormal Condition in Regulation of
Voltage Level>
[0294] FIG. 24 is a sequence diagram illustrating an operation in
an abnormal condition in regulation of a voltage level in power
supply control system 1# based on the second embodiment.
[0295] Referring to FIG. 24, sequences sq1 to sq3 and sq61 to sq63
are the same as the operations described with reference to FIG.
22.
[0296] Control circuit 24 of power delivery power supply unit 14#
instructs power supply circuit 20 to output a voltage based on
information on a voltage set in register 27. Thus, in sequence
sq63, an output voltage is changed from the old voltage to a new
voltage.
[0297] In the present example, occurrence of an abnormal condition
in power supply circuit 20 will be described.
[0298] Voltage determination circuit 23 does not output to control
circuit 24 an indication that an indicated voltage has attained to
(reached) the reference value in power supply circuit 20.
Therefore, control circuit 24 does not give a notification signal
to power delivery control unit 16#.
[0299] Power delivery control unit 16# determines whether or not a
notification signal has been received from power delivery power
supply unit 14# after lapse of a prescribed period since
transmission of voltage information to power delivery power supply
unit 14#. When power delivery control unit 16# determines that it
has not received a notification signal after lapse of a prescribed
period from power delivery power supply unit 14#, it gives a hard
reset notification to power delivery control unit 104 (sequence
sq70).
[0300] Power reception device 100 which is the consumption side
accepts the hard reset notification (sequence sq71). Thus, power
reception device 100 is set to the stand-by state in which supply
of a voltage from power feed device 10# is awaited.
[0301] Then, power feed device 10# which is the power feed side
gives a reset instruction (sequence sq72). Power delivery control
unit 16# instructs power delivery power supply unit 14# to
reset.
[0302] Power delivery power supply unit 14# changes a voltage upon
receiving the reset instruction from power delivery control unit
16# (sequence sq73). Control circuit 24 of power delivery power
supply unit 14# sets a voltage from power supply circuit 20 to 0 V
upon receiving the reset instruction.
[0303] In the present scheme, power delivery control unit 16#
determines whether or not it has received a notification signal
from power delivery power supply unit 14# after lapse of a
prescribed period since transmission of voltage information to
power delivery power supply unit 14#, and when it has not received
the notification signal, it gives a reset instruction so as to cut
off supply of a voltage. Therefore, when a voltage is abnormal,
safety of power feed by the power feed device can be enhanced by
cutting off a voltage.
[0304] <c11. Regulation of Voltage Level>
[0305] FIG. 25 is a flowchart when processing for regulating a
voltage level in power delivery control unit 16# based on the
second embodiment is performed.
[0306] Referring to FIG. 25, power delivery control unit 16#
determines whether or not a voltage request from power reception
device 100 which is the consumption side has been issued (step
S2).
[0307] When there is no voltage request from power reception device
100 which is the consumption side in step S2 (NO in step S2), power
delivery control unit 16# does not have to regulate a voltage level
and maintains a state in step S2.
[0308] When a voltage request from power reception device 100 which
is the consumption side has been issued in step S2 (YES in step
S2), power delivery control unit 16# checks a voltage request in
power feed (step S4).
[0309] Then, power delivery control unit 16# determines whether or
not the voltage request is OK (step S6). Specifically, power
delivery control unit 16# determines whether or not power can be
fed in response to the voltage request from power reception device
100. Whether or not a value of a requested voltage level is within
a power feed allowable range is checked.
[0310] When power delivery control unit 16# determines that the
voltage request is OK (YES in step S6), it gives a notification
that a voltage is permitted (step S8). Power delivery control unit
16# notifies power delivery control unit 104 of power reception
device 100 which is the consumption side that a voltage is
permitted. Power reception device 100 is thus set to the stand-by
state and waits for an instruction indicating being ready from the
power feed side.
[0311] Then, power delivery control unit 16# determines whether or
not it has received a notification that permission is accepted
(step S9).
[0312] Power delivery control unit 16# maintains step S9 until it
receives a notification that permission is accepted, and when it
determines that it has received the notification (YES in step S9),
it transmits voltage information to power delivery power supply
unit 14# (step S10#). Power delivery power supply unit 14# changes
a voltage upon receiving transmission of the voltage information
(an instruction to change).
[0313] Then, power delivery control unit 16# determines whether or
not a prescribed period has elapsed (step S12). The prescribed
period is set in advance to a period equal to or longer than a
period necessary until change to a new voltage is made from
transmission of voltage information to power delivery power supply
unit 14#.
[0314] When power delivery control unit 16# determines that a
prescribed period has elapsed (YES in step S12), it determines
whether or not a notification signal has been issued from power
delivery power supply unit 14# (step S13).
[0315] When power delivery control unit 16# determines in step S13
that the notification signal has been issued from power delivery
power supply unit 14# (YES in step S13), it notifies power
reception device 100 which is the consumption side that a voltage
is ready (step S14). Then, the process ends (end).
[0316] Power reception device 100 thus accepts the indication that
the voltage is ready, makes transition from the stand-by state to
the current consumption state, and is driven upon receiving supply
of a voltage from power feed device 10#.
[0317] When power delivery control unit 16# determines in step S6
that a voltage request is not OK (NO in step S6), it gives a
notification that a voltage is not permitted (not permitted) (step
S16).
[0318] Then, the process ends (end). In this case, requested power
supply to power reception device 100 is not started.
[0319] When power delivery control unit 16# determines in step S13
that no notification signal has been issued from power delivery
power supply unit 14# (NO in step S13), it gives a hard reset
notification to power reception device 100 which is the consumption
side (step S17).
[0320] Then, power delivery control unit 16# gives a reset
instruction to power delivery power supply unit 14# (step S18).
Power delivery power supply unit 14# sets a voltage to 0 V upon
receiving the reset instruction. Then, the process ends (end).
[0321] <c12. Operation for Regulating Voltage by Power Delivery
Power Supply Unit 14#>
[0322] FIG. 26 is a flowchart illustrating an operation for
regulating a voltage of power delivery power supply unit 14# based
on the second embodiment. An operation of control circuit 24 of
power delivery power supply unit 14# will be described.
[0323] Referring to FIG. 26, control circuit 24 determines whether
or not a value in the register storing an output voltage has been
changed in response to a voltage instruction from power delivery
control unit 16# (step S130).
[0324] When a value in the register storing an output voltage has
been changed in step S130 in response to the voltage instruction
from power delivery control unit 16# (YES in step S130), control
circuit 24 instructs power supply circuit 20 to output a voltage
value stored in register 27 (step S131).
[0325] Then, the process ends (end).
[0326] <b7. Operation for Determining Abnormal Condition During
Power Feed>
[0327] FIG. 27 is a sequence diagram illustrating a normal
operation during power feed from power delivery power supply unit
14# to power reception device 100 based on the second
embodiment.
[0328] Referring to FIG. 27, power delivery control unit 16# which
is the power feed side outputs a timer reset command for resetting
timer 25 to power delivery power supply unit 14# every prescribed
period (sequences sq80, sq81, sq82, and sq83).
[0329] Power delivery power supply unit 14# initializes a timer
value and starts counting upon receiving the timer reset command
from power delivery control unit 16#. This processing is repeated
each time of the timer reset command.
[0330] FIG. 28 is a sequence diagram illustrating an operation when
an abnormal condition occurs during power feed from power delivery
power supply unit 14# to power reception device 100 based on the
second embodiment.
[0331] Referring to FIG. 28, power delivery control unit 16# which
is the power feed side outputs a timer reset command for resetting
timer 25 to power delivery power supply unit 14# every prescribed
period (sequence sq90).
[0332] Power delivery power supply unit 14# initializes a timer
value and starts counting upon receiving the timer reset command
from power delivery control unit 16#.
[0333] In the present example, a timer value of timer 25 has
exceeded a prescribed value (timer overflow).
[0334] When power delivery power supply unit 14# determines that
the timer value has exceeded the prescribed value, it instructs
power delivery control unit 16# to perform a reset operation
(sequence sq91).
[0335] Power delivery control unit 16# performs a prescribed
initial launch operation in accordance with an instruction for a
reset operation from power delivery power supply unit 14# (sequence
sq92). The initial launch operation is an operation for resetting
entire power delivery control unit 16# based on a prescribed reset
program stored in memory 36.
[0336] Power delivery control unit 16# gives a hard reset
notification to power feed device 10# which is the power feed side
together with the initial launch operation (sequence sq93). Power
delivery control unit 16# gives a hard reset notification to power
delivery control unit 104.
[0337] Power reception device 100 which is the consumption side
accepts the hard reset notification (sequence sq94). Thus, power
reception device 100 is set to the stand-by state in which supply
of a voltage from power feed device 10# is awaited.
[0338] In response, power feed device 10# starts a voltage
regulation operation on its side (sequence sq95).
[0339] Power delivery control unit 16# transmits voltage
information to power delivery power supply unit 14# through
interface 30 and interface 28. Control circuit 24 of power delivery
power supply unit 14# has register 27 store information on a
voltage to be supplied (sequence sq96). Specifically, control
circuit 24 sets an initial value as information on a voltage to be
supplied in register 27. In the present example, 5 V is set.
[0340] Control circuit 24 of power delivery power supply unit 14#
instructs power supply circuit 20 to output a voltage based on
information on a voltage set in register 27. Thus, the output
voltage is changed from the old voltage to a new voltage (sequence
sq97).
[0341] In the present scheme, power delivery power supply unit 14#
instructs power delivery control unit 16# to perform a reset
operation when a prescribed condition is satisfied. Specifically,
when there is no input of a timer reset command periodically input
from power delivery control unit 16#, power delivery power supply
unit 14# determines that there is some kind of abnormal condition
in power delivery control unit 16# and gives an instruction to
perform a reset operation indicating execution of an initial launch
operation. Thus, power delivery power supply unit 14# can also
monitor a state of power delivery control unit 16#. Power delivery
control unit 16# can determine a state of power delivery power
supply unit 14# in accordance with a notification signal from
voltage determination circuit 23. Therefore, power delivery control
unit 16# and power delivery power supply unit 14# monitor states of
each other, and if there is an abnormal condition, they can perform
a reset operation. Therefore, safety of power feed by the power
feed device can be enhanced.
[0342] <c13. Operation for Timer Reset Command by Power Delivery
Control Unit 16#>
[0343] FIG. 29 is a flowchart illustrating an operation of power
delivery control unit 16# based on the second embodiment in
issuance of a timer reset command. An operation of microcomputer 34
of power delivery control unit 16# will be described.
[0344] Referring to FIG. 29, microcomputer 34 determines whether or
not a prescribed period has elapsed (step S140). Microcomputer 34
may determine whether or not a prescribed period has elapsed with
the use of timer 35.
[0345] When microcomputer 34 determines in step S140 that a
prescribed period has elapsed (YES in step S140), it outputs a
timer reset command (step S142).
[0346] Then, the process returns to step S140 and the process is
repeated.
[0347] <c14. Operation for Timer Reset Command by Power Delivery
Power Supply Unit 14#>
[0348] FIG. 30 is a flowchart illustrating an operation of power
delivery power supply unit 14# based on the second embodiment in
issuance of a timer reset command. An operation of control circuit
24 of power delivery power supply unit 14# will be described.
[0349] Referring to FIG. 30, control circuit 24 determines whether
or not a timer reset command has been input (step S150).
[0350] When control circuit 24 determines in step S150 that the
timer reset command has been input (YES in step S150), it resets
timer 25 (step S152).
[0351] Then, the process returns to step S150.
[0352] When control circuit 24 determines in step S150 that there
is no input of the timer reset command (NO in step S150), control
circuit 24 instructs to timer for counting (step S154).
[0353] Then, whether or not a timer value of timer 25 has exceeded
a prescribed value (timer over) is determined (step S156).
[0354] When it is determined in step S156 that a timer value of
timer 25 has exceeded the prescribed value (YES in step S156), a
reset operation instruction is given (step S158).
[0355] Then, the process ends (end).
[0356] When it is determined in step S156 that a timer value of
timer 25 has not exceeded the prescribed value (NO in step S156),
the process returns to step S150 and the process is repeated.
Third Embodiment
[0357] FIG. 31 is a diagram illustrating a configuration of a power
feed device 11 based on a third embodiment.
[0358] Referring to FIG. 31, power feed device 11 has a plurality
of USB connectors 12A and 12B. The USB data control unit is not
shown.
[0359] A power delivery power supply unit 14#A and a power delivery
control unit 16#A are included in correspondence with USB connector
12A.
[0360] A power delivery power supply unit 14#B and a power delivery
control unit 16#B are included in correspondence with USB connector
12B.
[0361] Since power delivery power supply units 14#A and 14#B are
basically similar in configuration to power delivery power supply
unit 14# in FIG. 20, detailed description thereof will not be
repeated. "A" and "B" are affixed to a reference numeral for each
constituent element of power delivery power supply unit 14# in FIG.
20.
[0362] Since power delivery control units 16#A and 16#B are
basically similar in configuration to power delivery control unit
16# in FIG. 20, detailed description thereof will not be repeated.
"A" and "B" are affixed to a reference numeral for each constituent
element of power delivery control unit 16# in FIG. 20.
[0363] A microcomputer 34A and a microcomputer 34B supply and
receive data to and from each other.
[0364] <c15. Regulation of Voltage Level>
[0365] FIG. 32 is a flowchart when processing for regulating a
voltage level in each of power delivery control units 16#A and 16#B
based on the third embodiment is performed.
[0366] Referring to FIG. 32, replacement of step S4 in which a
voltage request in power feed is checked with step S4# is different
from the flowchart in FIG. 25. Since other portions are the same as
described with reference to FIG. 25, detailed description thereof
will not be repeated.
[0367] FIG. 33 is a flowchart illustrating a sub routine process
for checking a voltage request in power feed in step S4#.
[0368] As shown in FIG. 33, power delivery control units 16#A and
16#B determine whether or not another port is being used (step
S160). For example, power delivery control unit 16#B determines
whether or not a USB device is connected to USB connector 12A which
is another port different from USB connector 12B which is a
corresponding port. Microcomputer 34B accesses microcomputer 34A
and checks whether or not a USB device is connected to USB
connector 12A.
[0369] When power delivery control units 16#A and 16#B determine in
step S160 that another port is being used (YES in step S160), they
obtain an amount of electric power used by another port (step
S162). For example, microcomputer 34B of power delivery control
unit 16#B accesses microcomputer 34A, and when it determines that a
USB device is connected to USB connector 12A, it obtains
information on an amount of electric power used by that USB
device.
[0370] Then, power delivery control units 16#A and 16#B calculate
an amount of suppliable electric power (step S164). Power delivery
control unit 16#B calculates an amount of suppliable electric power
by subtracting an amount of electric power used from a maximum
amount of suppliable electric power of power supply input AC or DC
power supply input.
[0371] Then, power delivery control units 16#A and 16#B obtain a
requested amount of electric power (step S166). Power delivery
control units 16#A and 16#B obtain requested amounts of electric
power based on voltage requests from USB devices connected to
corresponding USB connectors 12A and 12B, respectively.
[0372] Power delivery control units 16#A and 16#B determine whether
or not the obtained requested amounts of electric power of the USB
devices are within a range of an amount of suppliable electric
power (step S168).
[0373] When power delivery control units 16#A and 16#B determine in
step S168 that the requested amounts of electric power are within
the range of the amount of suppliable electric power (YES in step
S168), they make a determination as request OK (step S170).
[0374] Then, the process ends (return). The process proceeds to
step S6.
[0375] When power delivery control units 16#A and 16#B determine in
step S168 that the requested amounts of electric power are not
within the range of the amount of suppliable electric power (NO in
step S168), they give a request (step S172). Specifically, power
delivery control units 16#A and 16#B transmit to power reception
device 100, information that only electric power in the amount of
suppliable electric power can be fed. Power reception device 100
determines whether or not to request power feed in that amount of
electric power based on information that electric power only in the
amount of suppliable electric power can be fed. Since power
consumption can be reduced in drive of power reception device 100
in a power save mode, whether or not power can be fed by changing a
mode is determined. If electric power can be fed, power reception
device 100 outputs a notification of acceptance to power feed
device 10#.
[0376] Then, power delivery control units 16#A and 16#B determine
whether or not a notification of acceptance has been given from
power reception device 100 (step S174). Microcomputers 34A and 34B
of respective power delivery control units 16#A and 16#B determine
whether or not they have received a notification of acceptance from
power reception device 100.
[0377] When power delivery control units 16#A and 16#B determine in
step S174 that they have received the notification of acceptance
(YES in step S174), they make a determination as request OK for an
amount of suppliable electric power (step S176). Microcomputers 34A
and 34B of respective power delivery control units 16#A and 16#B
make a determination as request OK for an amount of suppliable
electric power. Then, the process ends (return). The process
proceeds to step S6.
[0378] When power delivery control units 16#A and 16#B determine in
step S174 that they have not received a notification of acceptance
(NO in step S174), they make a determination as request NG (step
S178). In this case, electric power is not fed to power reception
device 100.
[0379] Then, the process ends (return). The process proceeds to
step S6.
[0380] When power delivery control units 16#A and 16#B determine in
step S160 that another port is not being used (NO in step S160),
they obtain a requested amount of electric power (step S180). Power
delivery control units 16#A and 16#B obtain requested amounts of
electric power based on voltage requests from USB devices connected
to corresponding USB connectors 12A and 12B, respectively.
[0381] Power delivery control units 16#A and 16#B determine whether
or not the requested amounts of electric power are within the range
of the amount of suppliable electric power (step S182).
[0382] When power delivery control units 16#A and 16#B make a
determination in step S182 that the requested amounts of electric
power are within the range of the amount of suppliable electric
power (YES in step S182), they make a determination as request OK
(step S184).
[0383] Then, the process ends (return). The process proceeds to
step S6.
[0384] When power delivery control units 16#A and 16#B make a
determination in step S182 that the requested amounts of electric
power are not within the range of the amount of suppliable electric
power (NO in step S182), they make a determination as request NG
(step S186). Then, the process ends (return). The process proceeds
to step S6.
[0385] In the present scheme, with a plurality of USB connectors
12A and 12B being provided, for example, when a USB device is
attached to USB connector 12A and thereafter a USB device is
attached to USB connector 12B, whether or not electric power can be
fed to the USB device connected to USB connector 12B is determined.
Whether or not the requested amounts of electric power are within a
range of an amount of suppliable electric power is determined, and
when the requested amounts of electric power are not within the
range of the suppliable electric power, an inquiry request as to
whether or not feed with suppliable electric power to the USB
device can be done is issued.
[0386] When the USB device outputs a notification of acceptance in
response to the inquiry request, electric power in the amount of
suppliable electric power is fed. Accordingly, a voltage is
supplied from power delivery power supply unit 14# based on the
amount of suppliable electric power.
[0387] Thus, even when a total amount of electric power requested
by the plurality of USB devices exceeds the maximum amount of
suppliable electric power, whether or not electric power in an
amount of suppliable electric power can be fed is checked by
issuing a request. If electric power can be fed, electric power in
an amount of suppliable electric power is fed. Thus, electric power
can be fed from the power feed device to the plurality of USB
devices with safety of power feed at a high voltage being
ensured.
Fourth Embodiment
[0388] In the third embodiment, the process is performed by
supplying and receiving data between power delivery control unit
16#A and power delivery control unit 16#B. Without being limited to
such a configuration, for example, power delivery control unit 16#A
and power delivery control unit 16#B may both be managed.
[0389] FIG. 34 is a diagram illustrating a configuration of a power
feed device 11# based on a fourth embodiment.
[0390] Referring to FIG. 34, power feed device 11# includes a
plurality of USB connectors 12A and 12B.
[0391] Power delivery power supply unit 14#A and power delivery
control unit 16#A are included in correspondence with USB connector
12A.
[0392] Power delivery power supply unit 14#B and power delivery
control unit 16#B are included in correspondence with USB connector
12B.
[0393] In the present example, a power delivery management unit 19
managing power delivery control units 16#A and 16#B is further
provided.
[0394] Since each of power delivery power supply units 14#A and
14#B is basically similar in configuration to power delivery power
supply unit 14# in FIG. 20, detailed description thereof will not
be repeated. "A" and "B" are affixed to a reference numeral for
each constituent element of power delivery power supply unit 14# in
FIG. 20.
[0395] Since each of power delivery control units 16#A and 16#B is
basically similar in configuration to power delivery control unit
16# in FIG. 20, detailed description thereof will not be repeated.
"A" and "B" are affixed to a reference numeral for each constituent
element of power delivery control unit 16# in FIG. 20.
[0396] Microcomputer 34A and microcomputer 34B supply and receive
data to and from power delivery management unit 19.
[0397] Power delivery management unit 19 may perform a part of
processing in regulation of a voltage level described above.
[0398] Specifically, power delivery management unit 19 may perform
processing for checking a voltage request in power feed described
with reference to FIG. 33.
[0399] When there is a voltage request from power reception device
100 which is the consumption side, power delivery control units
16#A and 16#B output an indication to that effect to power delivery
management unit 19.
[0400] Then, power delivery management unit 19 checks a voltage
request in power feed.
[0401] Since the processing for checking a voltage request in power
feed in power delivery management unit 19 is the same as in the
flowchart described with reference to FIG. 15, detailed description
thereof will not be repeated.
[0402] Then, power delivery management unit 19 checks the voltage
request in power feed. When power can be fed, the power delivery
management unit makes a determination as request OK and provides
the determination to power delivery control units 16#A and
16#B.
[0403] Since processing thereafter is the same as described with
reference to FIG. 32, detailed description thereof will not be
repeated.
[0404] <Other Forms>
[0405] Though supply of a power supply voltage is received from
power feed device 10# in power reception device 100, power
reception device 100 can also include power delivery power supply
unit 14# and power delivery control unit 16# similarly to power
feed device 10#. Power reception device 100 can also have a
function as power feed device 10# and supply a power supply voltage
to yet another USB device.
[0406] Though the embodiments of the present invention have been
described, it should be understood that the embodiments disclosed
herein are illustrative and non-restrictive in every respect. The
scope of the present invention is defined by the terms of the
claims and is intended to include any modifications within the
scope and meaning equivalent to the terms of the claims.
* * * * *