JP2003273975A - Electronic device with wireless communication function and power supply control method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device requiring clock information, having a wireless communication function operated by a battery and particularly reducing the power consumption in the waiting state of wireless communication. <P>SOLUTION: A battery 17 always supplies power to an RF unit 12 and a reception monitoring unit 16. The reception monitoring unit 16 monitors reception information from the RF unit 12 and turns on a power switch 15 when detecting the reception of a connection request by the RF unit 12 to allow the battery 17 to supply power to a main controller 14. Thus, the main controller 14 is started. Then the main controller 14 captures clock information generated by an RTC (Real Time Clock) 161 in the reception monitoring unit 16, and sets it to an RTC 141 to start the RTC 141. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device which requires clock information and has a wireless communication function which is operated by a battery, and is particularly suitable for reducing power consumption in a standby state of wireless communication. The present invention relates to an electronic device having a function and a power supply control method in the device.

[0002]

2. Description of the Related Art Recently, various electronic devices having a wireless communication function which are operated by batteries have been developed. One of the electronic devices of this type is a portable external storage device which is configured to be portable and has a built-in storage unit, for example, a 1.8-inch HDD (hard disk drive). In addition to the HDD, the portable external storage device controls a wireless communication device (RF device) that performs wireless communication with another electronic device having a wireless communication function, and controls the HDD and a wireless communication device. A main control device that transmits and receives data between the HDD and the other electronic device via the HDD is provided. This main controller is, for example, a one-chip CPU, and has a built-in clock device (real time device) called RTC (Real Time Clock) that measures real time. This clock device is used for a time stamp or the like recorded when a data file is stored in the HDD.

By utilizing such a portable external storage device, a user can store large-capacity digital image data taken by an electronic camera or large-capacity data acquired by a portable information terminal as a portable external storage device. It is possible to store in the portable external storage device by wireless communication between the two.

[0004]

However, in the above-mentioned portable external storage device having the wireless communication function, the wireless communication device (RF device) and the main control device are always supplied with power even in the wireless communication standby state (connection waiting state). Was generally applied. Therefore, this type of portable external storage device has a problem that the power consumption is large and the standby time is short.

On the other hand, Japanese Unexamined Patent Application Publication No. 2001-102955 discloses a wireless communication device capable of ensuring a sufficient battery capacity even when the standby state for a long time is changed to the normal operation state. In the wireless communication device described in this publication, in a standby state for wireless communication, it is necessary to establish a wireless signal receiving unit corresponding to a part of the RF device and a wireless communication path between the wireless communication device itself and another wireless communication device. Power is supplied only to the identification means corresponding to another part of the RF device for identifying whether or not the main body activation part for activating the main body function part corresponding to the main control device is provided. When it is determined that the wireless communication path needs to be established, the main body activation means activates the main body functional part to supply power to the main body functional part and the radio signal reception means.

Therefore, in order to reduce the power consumption of a portable external storage device (electronic device) having a wireless communication function, it is conceivable to apply the power supply technique described in the above publication to the portable external storage device. That is, in the standby state of wireless communication, when power supply to the main control device in the portable external storage device is stopped by the main body starting means and it is necessary to establish a wireless communication path, that is, when the wireless communication function is provided. It is conceivable that when the connection request is given from the electronic device, the main body starting means starts the power supply to the main control device.

However, since the main controller incorporates the timepiece device (real-time device), the following problems newly occur. In other words, if the power supply to the main control unit is stopped in the standby state of wireless communication, the timepiece device stops, so even if the power supply to the main control unit is started after that, the timepiece device will not operate at the correct time. The problem is that the Such a problem is not limited to the portable external storage device described above, but is a main control device that performs data transmission / reception between a wireless communication device and another electronic device having a wireless communication function via the wireless communication device. Similarly, the same problem occurs in any electronic device having a wireless communication function that is operated by a battery and that includes a main control device that incorporates a timepiece device that measures real time.

The present invention has been made in consideration of the above circumstances, and an object thereof is to stop power supply to a main control unit in a standby state of wireless communication to reduce power consumption and always obtain correct time information. It is an object of the present invention to provide an electronic device having a wireless communication function and a power supply control method in the device, which can obtain

[0009]

According to one aspect of the present invention, there is provided an electronic device which requires clock information and has a wireless communication function which is operated by a battery. This electronic device is a wireless communication device that is constantly supplied with power from a battery,
It is composed of a power switch, a reception monitoring device to which power is constantly supplied from the battery, and a main control device to which power is supplied from the battery via the power switch. The wireless communication device wirelessly communicates with another electronic device having a wireless communication function. The reception monitoring device incorporates a first clock device that measures real time and generates clock information that can be fetched from the outside. The reception monitoring device monitors the reception information from the wireless communication device and, when detecting that the connection request is received by the wireless communication device, controls the power switch to be closed. The main control device incorporates a second timepiece device similar to the first timepiece device. The main controller transmits and receives data to and from the other electronic device via the wireless communication device. The main controller receives the electric power supplied from the battery when the power switch is controlled to be closed, is started, and outputs the time information at that time generated by the first clock device in the reception monitoring device. It is taken in and set in the second timepiece device, and the second timepiece device is started.

As described above, in the electronic device having the wireless communication function according to one aspect of the present invention, the power supply of the reception monitoring device and the main control device for monitoring the reception information from the wireless communication device (RF device) is opened and closed. By adding a switch that can be used, the power supply to the main control unit can be cut off during the period when it is not wirelessly connected to the external electronic device via the wireless communication device, that is, the period in the standby state for wireless connection. Electric power can be reduced. Moreover, the reception monitoring device is provided with the first clock device (RTC), and when the main control device is started, the time information at that time is read from the first RTC and the second RTC in the main control device is read. Since the second RTC is set to be activated and the second RTC is activated, even if the main control device is stopped during the wireless connection waiting state, the first control device in the main control device is activated after the main control device is activated. It becomes possible to generate correct time information with the RTC of 2. Further, when the time information is required, the main control device can obtain the time information from the second RTC in the main control device at high speed.

Here, if the main control device acquires the time information from the RTC in the reception monitoring device each time the main control device needs the time information, the RTC may not be provided in the main control device.

Further, when the electronic device having the wireless communication function can be connected to another electronic device by a communication interface other than the wireless communication device, the reception monitoring device has a memory and the wireless communication device is provided. When the reception monitoring device detects that the connection request has been received by, the activation factor corresponding to the connection request is stored in the memory, and the main control device, when starting, from the memory in the reception monitoring device It is advisable to take in the activation factor and set the corresponding communication mode.

In such a configuration, even if the main control unit is stopped during the standby state for wireless connection,
By fetching the activation factor from the memory in the reception monitoring device when the main control device is activated, it is possible to correctly set the communication mode in which communication via the wireless communication device is possible.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a portable external storage device having a wireless communication function will be described below with reference to the drawings.

FIG. 1 is a block diagram of a portable external storage device having a wireless communication function according to an embodiment of the present invention. The portable external storage device 10 shown in FIG.
The wireless communication device (hereinafter, referred to as RF device) 12 having an antenna 11, a storage unit such as an HDD (disk storage device) 13, a main control device 14, a power switch 15, and a reception monitoring device 16 are included. It

The RF device 12 performs radio communication by radio waves with another electronic device (hereinafter referred to as a radio communication device) 20 having a radio communication function via the antenna 11.
For example, it is a communication interface module represented by Bluetooth IF (interface). RF device 1
Power is constantly supplied to the battery 2 from the battery 17 via the power supply line 170.

The HDD 13 is, for example, a 1.8 inch H
It is a DD (hard disk drive). The HDD 13 is connected to the main controller 14 by an interface 130.

The main controller 14 is a portable external storage device 1.
It is, for example, a 1-chip CPU (main CPU) for controlling the entire 0. The main controller 14 performs data transmission / reception (data transfer) between the HDD 13 and the wireless communication device 20 via the RF device 12. The main controller 14 has a built-in clock device (hereinafter referred to as RTC) 141 for measuring real time, a RAM (not shown), and the like. Main controller 14 is supplied with power from battery 17 via power supply line 170 only while power switch 15 is on.

The power switch 15 is provided between a power line 170 which forms a power supply path from the battery 17 and a power terminal VDD of the main controller 14. By closing / opening (ON / OFF) the power switch 15, the power supply from the battery 17 to the main controller 14 is started / stopped (interrupted). The power supply of the main controller 14 is turned on / off according to whether the power switch 15 is closed or opened. When power is supplied to the main control device 14, the main control device 14 drives the HDD.
Power is supplied to 13.

The reception monitoring device 16 monitors the information received from the RF device 12, and when the RF device 12 receives a connection request from the wireless communication device 20 to the portable external storage device 10, it controls the power supply. The power switch 15 is turned on via the line 160. The reception monitoring device 16 is, for example, a one-chip CPU (sub CPU). The reception monitoring device 16 is
It operates by electric power constantly supplied from the battery 17 through the power supply line 170. The reception monitoring device 16 includes an RTC 161 similar to the RTC 141 in the main control device 14 and a RAM.
162 and ROM 163 are incorporated. RAM 162
Stores information indicating a factor of activating the portable external storage device 10. In the ROM 163, the reception monitoring device 1
In order to realize the reception monitoring function of 6, the reception monitoring device 1
The control program executed in 6 is stored. Between the reception monitoring device 16 and the main control device 14, a communication path 164 for reading from the main control device 14 the clock information indicated by the RTC 161 in the reception monitoring device 16 and the information stored in the RAM 162, and the main control device. A communication path 165 from 14 to notify the reception monitoring device 16 of the end of transmission / reception
And are connected.

Next, the portable external storage device 1 having the configuration shown in FIG.
A processing procedure (low power consumption control procedure) for reducing the power consumption of the portable external storage device 10 applied in No. 0 will be described with reference to the flowcharts of FIGS. 2 and 3.

First, it is assumed that the RF device 12 (including the portable external storage device 10) is in a standby state for wireless communication. In this state, the power switch 15 is off. That is, in the wireless communication standby state, the battery 17 supplies power to the RF device 12 and the reception monitoring device 16, but does not supply power to the main controller 14 and the HDD 13.

In this state, the reception monitoring device 16 is
The operation of monitoring the reception information from the RF device 12 and determining whether or not the connection request is received is repeated until it is determined that the connection request is received (steps S1 and S2).

In such a state, the portable external storage device 1
It is assumed that the connection request is wirelessly transmitted from the wireless communication device 20 that uses 0. When this connection request is received by the RF device 12 in the portable external storage device 10, the reception monitoring device 16 recognizes from the information received by the RF device 12 that the RF device 12 has received the connection request. judge.
Here, in the present embodiment in which the RF device 12 is the Bluetooth IF, the connection request (packet) from the wireless communication device 20 is the connection request (inquiry request) transmitted by broadcast and the target communication partner. ID
There are two types: a connection request (call request) that designates.
The operation of the reception monitoring device 16 is the same regardless of whether the RF device 12 receives an inquiry request or a call request connection request. That is, the reception monitoring device 16
When the RF device 12 determines that the connection request is received, the power control line 16 is activated to activate the main controller 14.
For example, by outputting a high-level power supply control signal to 0, the power switch 15 is turned on (step S3a). Further, the reception monitoring device 16 stores information indicating the activation factor of the main control device 14 (portable external storage device 10) in the RAM 162 (step S3b). In the present embodiment, the connection between the portable external storage device 10 and an external electronic device (the activation of the main control device 14 due to the connection) is the RF device 12.
Other communication interfaces, eg USB
(Universal Serial Bus) interface is also available. When the main control device 14 is activated by being connected to an external electronic device by another communication interface, that effect is R as an activation factor (connection factor).
It will be stored in the AM 162.

When the power switch 15 is turned on, power is supplied from the battery 17 to the main controller 14 via the power line 170. That is, the power supply of the main controller 14 is O
N is done. The main control device 14 is started by turning on the power source, and the reception monitoring device 16 operates the R in the reception monitoring device 16.
Current time information and RAM generated by TC161
The information (start factor information) stored in 162 is fetched via the communication path 164 (step S11). The main control unit 14 determines from which type of communication interface it is activated (connected) from the activation factor information loaded from the RAM 162, and sets the corresponding communication mode. Here, a mode is set in which data is transmitted and received by wireless communication via the RF device 12.

Next, the main control unit 14 includes the reception monitoring unit 16
The time information acquired from the main controller 14 is set in the internal RTC 141 of the main controller 14, and the RTC 14
1 is activated (step S12). As a result, the real-time clocking operation of the RTC 141 in the main control device 14 can be synchronized with the RTC 161 in the reception monitoring device 16 that is always operating, and the RTC 141 can generate correct time information.

When the main controller 14 is activated by the electric power supplied from the battery 17 through the power supply line 170,
The power is supplied to the HDD 13 via the main controller 14 to activate the HDD 13 (step S1).
3).

Then, the main controller 14 sets the RF device 12 and the wireless communication device 2 in a predetermined sequence following the connection request.
If a wireless communication path is established with 0 (step S1
4), H with the wireless communication device 20 via the RF device 12
Data transmission / reception requested by the wireless communication device 20 is started with the DD 13 (step S15).

On the other hand, the reception monitoring device 16 turns on the power switch 15 to turn on the power of the main control device 14 and stores the activation factor of the main control device 14 in the RAM 162 (steps S3a, S3b). A timer (not shown) that measures a predetermined fixed time is started (step S4). Then, the reception monitoring device 16 determines whether or not a wireless communication path is established between the RF device 12 and the wireless communication device 20 before the timer times out, that is, before a fixed time elapses from the time when the connection request is received. Is determined by monitoring the reception information indicating the state of the RF device 12 (steps S5 and S6).

If the timer times out,
When the wireless communication path is not established, the reception monitoring device 1
6 indicates that the portable external storage device 10 has not been selected, and outputs a low-level power control signal to the power switch 15 via the power control line 160 to turn off the power switch 15 (step S7). . This allows
The power supply to the main controller 14 is cut off, and the portable external storage device 10 is again in the standby state for wireless communication.

On the other hand, before the time-out occurs, the RF device 1
2 establishes a wireless communication path between the wireless communication device 20 and the wireless communication device 20,
When the main control device 14 starts data transmission / reception, the reception monitoring device 16 monitors the reception information from the RF device 12 and the transmission / reception end signal notified from the main control device 14 via the communication path 164, and transmits the data. The operation of determining whether transmission / reception has ended is repeated until it is determined that data transmission / reception has ended (steps S8 and S9). If it can be determined from the reception information from the RF device 12 or the transmission / reception end signal from the main control device 14 that the data transmission / reception between the wireless communication device 20 and the portable external storage device 10 is completed,
The reception monitoring device 16 turns off the power switch 15 (step S7). On the other hand, when data transmission / reception between the wireless communication device 20 and the portable external storage device 10 is continued, the reception monitoring device 16 receives the reception information from the RF device 12 and the transmission / reception end signal from the main control device 14. Continue to monitor.

As is apparent from the above description, in the present embodiment, the power switch 15 is turned off in the standby state of the wireless communication in the portable external storage device 10, so that the main control unit 14 receives the battery 17 from the battery 17. No power is supplied. As a result, the portable external storage device 10 (main controller 14 and HDD 1 in the standby state)
Power consumption in 3) can be reduced.

Further, in the present embodiment, the RTC 16 is provided in the reception monitoring device 16 separately from the RTC 141 in the main control device 14.
1 and the RAM 162 are built in, and the RTC 161 and the RAM 162 are configured to be constantly supplied with electric power. Here, the RTC 161 measures the real time even during a period in which power is not supplied to the main controller 14,
The correct clock information is always generated. Similarly, the activation factor of the main control device 14, in other words, the connection factor with the external electronic device (here, the wireless communication device 20) is also stored in the RAM 162 in the reception monitoring device 16.

Therefore, even if the RAM in the main control unit 14 is stopped until the main control unit 14 is activated, the RAM 162 in the reception monitoring unit 16 is activated when the main control unit 14 is activated. By importing the activation factor information from the device, a communication mode suitable for the activation factor is set, and communication with an external electronic device (here, the wireless communication device 20) is performed.
Correct data transmission / reception can be performed.

Even if the RTC 141 in the main control unit 14 is stopped until the main control unit 14 is activated, the RTC 141 is activated when the main control unit 14 is activated.
By acquiring the time information at that point in time from 161 and setting it in the RTC 141 in the main control unit 14 and activating the RTC 141, the time information used by the main control unit 14 for a time stamp or the like is correctly generated by the RTC 141. it can. As a result, when a process requiring clock information occurs after the start of data transmission / reception (step S16), the main controller 14 detects the RTC1 in the main controller 14.
A process that reads out the time information generated by 41 at high speed and requires the time information, for example, the time information is associated with a data file as a time stamp in the HDD.
It is possible to perform the process of recording in 13 (step S1)
7, S18).

Now, in the portable external storage device 10 of FIG.
When the main control device 14 is in the operating state, the current consumption in the main control device 14 is several hundreds mA, of which RTC1
The current consumption of 41 is several hundred μA. On the other hand, the current consumption of the reception monitoring device 16 is several mA, and the current consumption of the RTC 161 is the same as the current consumption of the RTC 141, which is several hundred μA. As is apparent, the consumption current in the reception monitoring device 16 is 1/100 of the consumption current in the main control device 14, and the power consumption is 1/10000. Also, RTC1
The power consumption of 41 and 161 is negligibly smaller than the power consumption of the main control device 14 and the reception monitoring device 16.

That is, in the present embodiment, the RTC 16
Even if the built-in reception monitoring device 16 is provided and power is constantly supplied to the reception monitoring device 16, the RTC 141
The power consumption can be significantly reduced as compared with the conventional technique in which the built-in main controller 14 is always supplied with power.

In the above embodiment, the RTC 161 is provided to the reception monitoring device 16 and the RTC 141 is also provided to the main control device 14. However, the main controller 1
A configuration in which the RTC 141 in 4 is unnecessary is also possible. To this end, as shown in the flowchart of FIG. 4, each time a process that requires time information occurs in the main control device 14 (step S21), the main control device 14 receives the current information from the RTC 161 in the reception monitoring device 16. Channel 1 for time information
It may be configured to capture via 64 (step S2
2). In this case, the main control device 14 is provided with the reception monitoring device 16
The time information fetched from the RTC 161 in the inside may be used (step S23). With this configuration, it is difficult to obtain time information at high speed as compared with the above embodiment. Therefore, this configuration is suitable for an electronic device that does not need to acquire time information at high speed, such as using time information as a time stamp, as in the example of the portable external storage device 10 in FIG.

In the above embodiment, the case where the present invention is applied to the portable external storage device 10 has been described. However, the present invention is applicable to any electronic device that requires clock information and has a wireless communication function that operates on a battery. Further, the wireless communication is not limited to the wireless communication by radio waves, and may be infrared communication, for example.

Furthermore, an electronic device having no wireless communication function,
For example, waiting for a request from another electronic device (host),
That is, the present invention is applied to an electronic device having a communication interface that is connected to another electronic device by wire in which a standby state corresponding to the standby state of the wireless communication (wireless connection) in the above-described embodiment occurs, and a It is also possible to supply power to the main control device of the electronic device only when requested. An example of such an electronic device is an external storage device such as an HDD that performs a read / write operation in response to an access request from a host.

The present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the spirit of the invention. Furthermore, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the section of the problem to be solved by the invention can be solved, and the effect described in the section of the effect of the invention can be solved. If you get
A configuration in which this component is deleted can be extracted as an invention.

[0042]

As described above in detail, according to the present invention, it is possible to reduce power consumption by stopping the power supply to the main control unit in the standby state of wireless communication.
Moreover, according to the present invention, the reception monitoring device for monitoring the reception state in the wireless communication device is provided with the clock device (RTC), and the main control device takes in the time information from the clock device in the reception monitoring device at the time of starting. Therefore, the correct time information can always be obtained by setting the time information in the main control device or by acquiring the time information from the time device in the reception monitoring device and using the time information each time the time information is needed. .

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a portable external storage device having a wireless communication function according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the reception monitoring device 16 in the same embodiment.

FIG. 3 is a flowchart for explaining the operation of main controller 14 in the same embodiment.

FIG. 4 is a flowchart showing a modified example of the operation of main controller 14.

[Explanation of symbols]

10 ... Portable external storage device (electronic device having wireless communication function) 11 ... Antenna 12 ... RF device (wireless communication device) 13 ... HDD 14 ... Main control device 15 ... Power switch 16 ... Reception monitoring device 17 ... Battery 141 161 ... RTC (timepiece device) 160 ... Power supply control line 161 ... RTC (timepiece device) 162 ... RAM (memory) 164, 165 ... Communication path

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koichi Chiba             Toshiba, 3-3-3 Shinmachi, Ome-shi, Tokyo             Digital Media Engineering Stock Association             In-house (72) Inventor Koichi Kobayashi             2-9 Suehiro-cho, Ome City, Tokyo Stock Market             Company Toshiba Ome Factory F term (reference) 5B011 DA06 EA10 KK14 LL06                 5K027 BB17 HH27 MM04                 5K034 AA15 EE03 FF02 FF05 HH65                       KK02 LL01 TT02 TT07

Claims (7)

[Claims] 1. An electronic device which requires clock information and has a wireless communication function which is operated by a battery, is constantly supplied with power from a battery, and wirelessly communicates with another electronic device having a wireless communication function. It incorporates a wireless communication device for performing, a power switch for supplying / shutting off power from the battery, and a first clock device for measuring real time and generating clock information that can be fetched from the outside. A reception monitoring device to which power is constantly supplied, monitors reception information from the wireless communication device, and closes the power switch when detecting that a connection request is received by the wireless communication device. A main unit that incorporates a reception monitoring device and a second clock device that generates clock information by measuring real time, and that transmits and receives data to and from the other electronic device via the wireless communication device. Control device that is activated by receiving power supplied from the battery when the power switch is controlled to be closed, and is generated by the first clock device in the reception monitoring device, the time at that time An electronic device having a wireless communication function, comprising: a main control device that takes in information and sets it in the second timepiece device to activate the second timepiece device. 2. An electronic device which requires clock information and has a wireless communication function which is operated by a battery, and which is constantly supplied with power from a battery and wirelessly communicates with another electronic device having a wireless communication function. A wireless communication device inside the electronic device for performing, a power switch for supplying / shutting off the electric power from the battery, and a clock device for clocking real time to generate clock information that can be fetched from the outside are built in, A reception monitoring device that is constantly supplied with power from a battery, monitors reception information from the wireless communication device, and closes the power switch when detecting that a connection request is received by the wireless communication device. A reception monitoring device to be controlled, and the power switch is controlled to be closed to be activated by receiving power supplied from the battery, and the other device via the wireless communication device. A main control device that transmits and receives data to and from a slave device, and captures and uses time information at that time generated by the clock device in the reception monitoring device each time time information is needed. An electronic device having a wireless communication function, comprising: a main control device. 3. When the reception monitoring device detects the end of data transmission / reception with the other electronic device by reception information from the wireless communication device or a specific signal from the main control device, the reception monitoring device turns on the power switch. An electronic device having a wireless communication function according to claim 1 or 2, which is controlled to be opened. 4. The reception monitoring apparatus is configured to connect the other electronic device and the wireless communication apparatus to each other even after a predetermined time elapses after detecting that a connection request is received by the wireless communication apparatus. The electronic device having a wireless communication function according to claim 1 or 2, wherein the power switch is controlled to be opened when a wireless communication path between them is not established. 5. The reception monitoring device has a built-in memory for holding a factor for activating the main control device, and when the connection request is received by the wireless communication device, the connection is detected. The starting factor corresponding to the request is stored in the memory, and the main control unit fetches the starting factor from the memory in the reception monitoring device at the time of starting, and sets a corresponding communication mode. Item 1
Alternatively, an electronic device having a wireless communication function according to claim 2. 6. A power supply control method in an electronic device which requires clock information and has a wireless communication function which is operated by a battery, and is provided with another electronic device which is constantly supplied with power from a battery and has a wireless communication function. When a wireless communication device inside the electronic device that performs wireless communication between devices is in a standby state for wireless communication, the reception information from the wireless communication device is monitored by a reception monitoring device that is constantly supplied with power from the battery. And, when it is detected that the connection request is received by the wireless communication device, by controlling the power switch to be closed by the reception monitoring device, the other electronic device via the wireless communication device. Supplying a power from the battery to a main control device that transmits and receives data between the main control device and the main control device receiving the power supplied from the battery. The main control unit captures the time information at that time, which is generated by the first clock unit incorporated in the reception monitoring apparatus, and the clock information captured by the main control unit. A step of setting the second timepiece device built into the main control device by the main control device and activating the second timepiece device. Method. 7. A power supply control method for an electronic device which requires clock information and has a wireless communication function which is operated by a battery, and which is supplied with power from a battery at all times and is connected to another electronic device having a wireless communication function. When a wireless communication device inside the electronic device that performs wireless communication between devices is in a standby state for wireless communication, the reception information from the wireless communication device is monitored by a reception monitoring device that is constantly supplied with power from the battery. And, when it is detected that the connection request is received by the wireless communication device, by controlling the power switch to be closed by the reception monitoring device, the other electronic device via the wireless communication device. Supplying a power from the battery to a main control device that transmits and receives data between the main control device and the main control device receiving the power supplied from the battery. Each time the time information is needed after being activated by the main controller, the main controller acquires the time information at that time, which is generated by a clock device built in the reception monitoring device. And a step in which the main control device uses the clock information, the power control method in an electronic device having a wireless communication function.