JP7546536B2 - Electronic clock - Google Patents

Description

The present invention relates to an electronic watch.

There is a conventional technology for storing data in non-volatile memory. Patent Document 1 discloses a technology for a clock that includes a time counter that measures time, a means for detecting in advance that the power supply will be cut off, a means for storing current time data from the time counter in non-volatile memory when a power supply cut is detected in advance, a conversion means for reading the time data from the non-volatile memory and converting it to time data with a preset time added when the power supply is restored and the clock is restarted, and a means for setting the converted time data in the time counter.

JP 2006-52962 A

When a watch stops operating due to a drop in battery voltage, if the power consumption required to store information in non-volatile memory is large, this will cause the battery voltage to drop further. As a result, if the battery voltage falls below the minimum operating voltage required for writing, it may not be possible to save all necessary information. It is desirable to be able to store necessary information in non-volatile memory when the watch resumes from a stopped state while suppressing the drop in battery voltage.

The object of the present invention is to provide an electronic watch that can store necessary information in non-volatile memory when returning from a stopped state while suppressing a drop in battery voltage.

The electronic watch of the present invention comprises a control unit having a first non-volatile memory and controlling the time display, a second non-volatile memory arranged outside the control unit, and a battery supplying power to the control unit and the second non-volatile memory, the power consumption of the second non-volatile memory when storing data is less than the power consumption of the first non-volatile memory when storing the data, the control unit transitions to a stop mode in which the operation of the control unit is stopped when the voltage of the battery drops, and when the control unit transitions to the stop mode, it stores in the second non-volatile memory recovery information that is information that the control unit refers to when resuming operation.

When the control unit of the electronic watch according to the present invention transitions to a stop mode, it stores in the second non-volatile memory recovery information, which is information that the control unit refers to when resuming operation. The electronic watch according to the present invention has the effect of being able to store in the non-volatile memory the information required when resuming operation from a stopped state while suppressing a drop in battery voltage.

FIG. 1 is a plan view of an electronic timepiece according to an embodiment of the invention. FIG. 2 is a cross-sectional view of the electronic timepiece according to the embodiment. FIG. 3 is a block diagram of an electronic timepiece according to an embodiment of the present invention. FIG. 4 is a sequence diagram of a storage operation according to the embodiment. FIG. 5 is a sequence diagram of a return operation according to the embodiment. FIG. 6 is a sequence diagram of a storage operation according to the embodiment. FIG. 7 is a sequence diagram of a storage operation according to the embodiment. FIG. 8 is a diagram of a second non-volatile memory according to an embodiment. FIG. 9 is a sequence diagram of a storage operation according to the embodiment. FIG. 10 is a sequence diagram of a storage operation according to the embodiment. FIG. 11 is a sequence diagram of a storage operation according to the first modified example of the embodiment. FIG. 12 is a sequence diagram of a return operation according to a first modified example of the embodiment. FIG. 13 is a sequence diagram of a return operation according to a first modified example of the embodiment. FIG. 14 is a sequence diagram according to a second modified example of the embodiment. FIG. 15 is a sequence diagram according to a second modified example of the embodiment.

The electronic watch according to the embodiment of the present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to this embodiment. Furthermore, the components in the following embodiment include those that a person skilled in the art would easily imagine or that are substantially the same.

[Embodiment]
An embodiment will be described with reference to Fig. 1 to Fig. 10. The embodiment relates to an electronic watch. Fig. 1 is a plan view of the electronic watch according to the embodiment, Fig. 2 is a cross-sectional view of the electronic watch according to the embodiment, Fig. 3 is a block diagram of the electronic watch according to the embodiment, Fig. 4 is a sequence diagram of a save operation according to the embodiment, Fig. 5 is a sequence diagram of a restore operation according to the embodiment, Figs. 6 and 7 are sequence diagrams of a save operation according to the embodiment, Fig. 8 is a diagram of a second non-volatile memory according to the embodiment, and Figs. 9 and 10 are sequence diagrams of a save operation according to the embodiment.

The electronic watch 1 of this embodiment is a wristwatch worn on the wrist of a user. As shown in FIG. 1, the electronic watch 1 is an analog electronic watch with hands 6. As shown in FIGS. 1 and 2, the electronic watch 1 has an outer case 10, a dial 11, and a transparent crystal 12. As shown in FIG. 2, the outer case 10 has a main body 10a (body), a bezel 10b, and a back cover 10c. The main body 10a and the bezel 10b are each cylindrical members that fit together and have internal spaces for arranging the hands, dial, circuit board, battery, etc. described below. The back cover 10c closes the opening on the back side of the main body 10a. The crystal 12 closes the opening on the front side of the bezel 10b.

As shown in FIG. 2, the internal space of the exterior case 10 contains the hands 6, dial 11, antenna 32, solar panel 13, magnetic sheet 14, date wheel 64, circuit board 15, battery 4, etc. The hands 6 have an hour hand 61, a minute hand 62, and a second hand 63. The dial 11 is configured to transmit light.

The antenna 32 is disposed on the rear side of the dial 11. The antenna 32 is an antenna for wireless communication, and has a substrate 32a and an antenna wire 32b. As shown in FIG. 1, the antenna wire 32b is arranged in a spiral shape. The substrate 32a is configured to transmit light. The solar panel 13 is disposed on the rear side of the substrate 32a. The power generated by the solar panel 13 is stored in the battery 4.

The magnetic sheet 14 is disposed on the rear side of the solar panel 13. In other words, the magnetic sheet 14 is disposed between the antenna 32 and the motor 5. The magnetic sheet 14 shields the antenna 32 from the magnetic field generated by the motor 5.

The date wheel 64 is arranged on the rear side of the magnetic sheet 14. The date wheel 64 is arranged, for example, coaxially with the hand 6. The circuit board 15 is arranged on the rear side of the date wheel 64. The communication control unit 3 and the control unit 2 are mounted on the circuit board 15. The motor 5 and the gear train 7 are arranged between the circuit board 15 and the date wheel 64. The motor 5 is connected to the hand 6 and the date wheel 64 via the gear train 7. The motor 5 in this embodiment is a step motor, and is connected to the control unit 2 via the circuit board 15. The antenna wire 32b of the antenna 32 is connected to the communication control unit 3 via the connection member 33 and the circuit board 15.

The battery 4 is a secondary battery that can be charged and discharged. The battery 4 is arranged on the rear side of the circuit board 15. The battery 4 supplies power to the control unit 2, the communication control unit 3, and the motor 5.

As shown in FIG. 3, the control unit 2 has a control circuit 20, a first non-volatile memory 21, and a RAM 22. The control unit 2 is, for example, a microcomputer that performs various operations including timekeeping. The control circuit 20 performs various operations as a clock, including calculating the internal time of the clock and controlling the motor.

The first non-volatile memory 21 is a non-volatile memory arranged in the control unit 2. The first non-volatile memory 21 is, for example, a flash memory or an EEPROM. The first non-volatile memory 21 may store a program executed by the control circuit 20. The first non-volatile memory 21 may store adjustment values related to the detection of the internal time of the clock and the battery voltage. The RAM 22 is used, for example, as a working memory for the control circuit 20.

The communication control unit 3 of this embodiment is a communication IC that performs wireless communication. The wireless communication method by the communication control unit 3 is, for example, NFC (Near Field Communication). The communication control unit 3 can perform short-distance wireless communication with the external device 100. The communication control unit 3 has a communication circuit 30 and a second non-volatile memory 31. The second non-volatile memory 31 is, for example, a flash memory or an EEPROM. The communication circuit 30 is a circuit that performs wireless communication. The communication circuit 30 further performs serial communication with the control circuit 20. The communication circuit 30 can write data to the second non-volatile memory 31 and read data from the second non-volatile memory 31. The communication control unit 3 is connected to the control unit 2 via the circuit board 15.

In the electronic watch 1 of this embodiment, the power consumption of the second non-volatile memory 31 when storing data is less than the power consumption of the first non-volatile memory 21 when storing data. In other words, when storing the same amount of data, the power consumption of the second non-volatile memory 31 is less than the power consumption of the first non-volatile memory 21. For example, the current value consumed when the second non-volatile memory 31 stores data is less than the current value consumed when the first non-volatile memory 21 stores data.

The external device 100 is, for example, a communication terminal such as a smartphone. The external device 100 has a control unit 110, a memory unit 120, and a communication unit 130. The communication unit 130 performs short-range wireless communication with the communication control unit 3. The memory unit 120 has at least a non-volatile memory. The control unit 110 controls wireless communication by the communication unit 130, and also controls writing of data to the memory unit 120 and reading of data from the memory unit 120. It is preferable that an application program that links with the electronic watch 1 via wireless communication is installed in the external device 100.

The control circuit 20 of the electronic watch 1 controls wireless communication by the communication control unit 3. The control circuit 20 can, for example, allow or prohibit wireless communication with the communication control unit 3. The control circuit 20 can also instruct the communication control unit 3 to write data to the second non-volatile memory 31 and read data from the second non-volatile memory 31.

The control circuit 20 controls the motor 5 based on the internal time of the watch. The control circuit 20 generates a pulse signal that is output to the drive circuit of the motor 5. The control circuit 20 drives the motor 5 with the pulse signal, causing the hands 6 and the date wheel 64 to rotate.

The electronic watch 1 has a normal mode in which the control unit 2 is operating, and a stop mode in which the control unit 2 is stopped operating. The normal mode is a time display mode in which the electronic watch 1 displays the time based on the watch's internal time. The normal mode may also include a power saving mode in which power consumption in the electronic watch 1 is reduced. In the power saving mode, for example, the movement of some of the hands among the hour hand 61, minute hand 62, and second hand 63 is stopped.

When writing and reading data in normal mode, the electronic watch 1 uses the first non-volatile memory 21, which is an internal memory. The first non-volatile memory 21 is more responsive than the second non-volatile memory 31, which is an external memory. In normal mode, the control unit 2 stores adjustment values related to timekeeping and battery voltage detection in the first non-volatile memory 21 and periodically refers to these adjustment values.

The stop mode is a power break mode in which the power supply to the control unit 2 is stopped. When the control unit 2 transitions to the stop mode, it stops calculating the time inside the clock and stops generating the pulse signal. The control unit 2 transitions from the normal mode to the stop mode when the voltage of the battery 4 drops. When transitioning to the stop mode, the control unit 2 stores the return information in the second non-volatile memory 31. The return information is information that the control unit 2 refers to when resuming operation. In the following explanation, the operation of storing the return information in the non-volatile memory is simply referred to as the "save operation."

The recovery information includes, for example, a BAT flag, time information, motor steering, hand position, city information, daylight saving time information, dual city information, alarm settings, data log, event log, etc. The BAT flag is a flag that indicates that the reset was caused by a transition to stop mode. When the value of the BAT flag indicates a transition to stop mode, recovery information has been written to non-volatile memory. In this case, the control unit 2 resumes operation based on the recovery information.

The time information is the value of the internal time of the watch when it transitions to the stop mode. The time information includes, for example, values of year, month, day, week, hour, and minute. The motor steering is information about the last pulse output to the motor 5. Based on the motor steering, the phase (pole) of the pulse to be output first when the hand movement is resumed is determined. If the electronic watch 1 has multiple motors 5, the motor steering for each motor 5 is stored.

The hand position is the position of the pointer 6 when transitioning to stop mode. The amount of data for the hand position is determined according to the number of motors 5 and the maximum number of steps for the motors 5. The city information is information about the city that was selected when transitioning to stop mode. The daylight saving time information is the setting value for daylight saving time for each city. The dual city information is the setting value when the electronic clock 1 displays the time in multiple cities.

The alarm setting is information about the alarm time that was set when the electronic watch 1 transitioned to stop mode. The data log includes information such as the number of times an event occurred in the electronic watch 1. The event log is chronological data about what events occurred in the electronic watch 1 before it entered stop mode.

The electronic watch 1 of this embodiment can reduce the power consumption required for the save operation by storing the recovery information in the second non-volatile memory 31. In other words, the electronic watch 1 of this embodiment can save the recovery information in the non-volatile memory while suppressing a drop in battery voltage. Therefore, the electronic watch 1 of this embodiment can save the recovery information more reliably.

The process of transitioning to the stop mode will be described with reference to the sequence diagram of FIG.
S1: The control unit 2 detects a voltage drop in the battery 4.
S2: The control unit 2 determines that the condition for transitioning to the stop mode is met, for example, when the voltage V of the battery 4 remains below the lower limit V0 for a predetermined period of time.
S3: The control unit 2 stops timekeeping and stops the movement of the hands. The control unit 2 stops calculation of the internal time of the watch and stops all of the hands 6.

S4: The control unit 2 transmits a write command to the communication control unit 3. The control unit 2 transmits a command including recovery information data.
S5: The communication control unit 3 that has received the write command writes the recovery information into the second non-volatile memory 31.
S6: When the writing of the recovery information is completed, the communications control unit 3 transmits a response to the write command to the control unit 2.
S7: When the control unit 2 receives the response, it transitions to a stop mode. The power supply from the battery 4 to the control unit 2 is stopped, and the control unit 2 stops operating.

Next, the process performed when the control unit 2 resumes operation will be described with reference to FIG.
S11: The voltage of the battery 4 increases due to the power generated by the solar panel 13. The control unit 2 has a circuit that starts up the control unit 2 when the battery voltage increases.
S12: The start-up condition is met and the control unit 2 starts up. The start-up condition is, for example, that the voltage V of the battery 4 is equal to or higher than a predetermined value V1. The predetermined value V1 is a voltage value greater than a lower limit value V0.
S13: The started control unit 2 transmits a read command to the communication control unit 3. This read command instructs the reading of recovery information.
S14: The communication control unit 3 that has received the read command reads the recovery information from the second non-volatile memory 31. The communication control unit 3 transmits the read recovery information to the control unit 2 as a response to the read command.
S15: The control unit 2 develops the return information in the RAM 22 and stores it in the RAM 22.
S16: The control unit 2 transitions to a standby state before returning to the normal mode. In the standby state, the control unit 2 can calculate the internal time of the watch. In the standby state, the movement of the hands 6 may be stopped.

The condition for returning to the normal mode is, for example, that the voltage V of the battery 4 remains at or above a predetermined value V1 for a predetermined period of time. When the return condition is met, the control unit 2 transitions from the standby state to the normal mode. At this time, the control unit 2 starts various displays, including the time display. For example, the control unit 2 moves the hands 6 to a position corresponding to the internal time of the watch and starts moving them.

Here, there is a possibility that another command may be sent to the communication control unit 3 while the save operation is being performed. For example, as shown in FIG. 6, it is assumed that a command may be sent from the external device 100 to the communication control unit 3 via wireless communication. The operation of the communication control unit 3 in this case will be described below.

S21: The control unit 2 determines that the condition for switching to the stop mode is met. The control unit 2 stops timing and stops the movement of the hands.
S22: The control unit transmits a write command to the communication control unit 3.
S23: The communication control unit 3 that has received the write command writes the recovery information into the second non-volatile memory 31.
S24: During the execution of writing, a write command is sent from the external device 100 to the communication control unit 3. The communication control unit 3 is configured to perform exclusive control that does not accept other commands while operating in one operation mode, for example. In other words, the communication control unit 3 does not respond to other commands while writing the recovery information. If there is no response from the communication control unit 3 within a specified time, the external device 100 determines that an error has occurred.
S25: When the writing of the recovery information is completed, the communications control unit 3 transmits a response to the write command to the control unit 2.
S26: When the control unit 2 receives the response, it transitions to the stop mode.

The above-mentioned exclusive control allows the save operation to be completed without interruption. This makes it possible to save the recovery information more reliably. Note that the above-mentioned exclusive control is not limited to the specifications of the communication control unit 3. For example, when the control unit 2 sends a command to write the recovery information, the control unit 2 may prohibit the communication control unit 3 from responding to the command via wireless communication. In other words, while the control unit 2 is storing the recovery information in the second non-volatile memory 31, the control unit 2 may prohibit the communication control unit 3 from responding to commands via wireless communication.

When the communication control unit 3 receives another command while the save operation is being performed, the communication control unit 3 may delay the processing of the other command as shown in Fig. 7. The operation of the electronic watch 1 in this case will be described below.
S31: The control unit 2 determines that the condition for switching to the stop mode is met. The control unit 2 stops timing and stops the movement of the hands.
S32: The control unit 2 transmits a write command to the communication control unit 3.
S<b>33 : The communication control unit 3 that has received the write command writes the recovery information into the second non-volatile memory 31 .
S34: During the execution of writing, a write command is sent from the external device 100 to the communication control unit 3. The communication control unit 3 delays the processing of the write command received subsequently.
S35: When the communication control unit 3 completes writing the recovery information, it transmits a response to the write command to the control unit 2.
S36: When the control unit 2 receives the response, it transitions to the stop mode.
S37: After transmitting the response to the control unit 2, the communication control unit 3 starts processing the write command received from the external device 100. The communication control unit 3 writes the data received from the external device 100 to the second non-volatile memory 31.
S38: When the writing is completed, the communications control unit 3 transmits a response to the write command to the external device 100.

The above sequential command processing allows the save operation to be completed without interruption. This makes it possible to save the recovery information more reliably. Note that the above sequential command processing is not limited to the specifications of the communication control unit 3. For example, when the control unit 2 sends a command to write the recovery information, it may instruct the communication control unit 3 to delay the processing of other commands. In other words, while the control unit 2 is storing the recovery information in the second non-volatile memory 31, it may delay the execution of commands via wireless communication in the communication control unit 3.

It is undesirable that the recovery information written in the second non-volatile memory 31 is overwritten by other data. Therefore, a memory area for recovery information and a memory area for other data may be separated. For example, as shown in FIG. 8, a memory area for recovery information may be reserved in the second non-volatile memory 31. The second non-volatile memory 31 has a first memory area 31a for wireless communication and a second memory area 31b for recovery information.

When the communication control unit 3 receives a write command from the external device 100, it writes the received data to the first memory area 31a. On the other hand, when the communication control unit 3 receives a write command from the control unit 2, it writes the recovery information to the second memory area 31b. This makes it possible to prevent the recovery information from being overwritten during the stop mode.

Next, referring to FIG. 9, we will explain the operation of the electronic watch 1 when the communication control unit 3 is BUSY during the save operation.

S41: The control unit 2 determines that the condition for switching to the stop mode is met. The control unit 2 stops timing and stops the movement of the hands.
S 42 : The external device 100 transmits a write command to the communication control unit 3 .
S 43 : The communication control unit 3 that has received the write command writes the data received from the external device 100 into the second non-volatile memory 31 .
S44: The control unit 2 transmits a write command to the communication control unit 3.
S45: If the communication control unit 3 is currently processing a write command, it returns a BUSY response to the control unit 2.
S46: Having received the BUSY response, the control unit 2 waits until a predetermined time has elapsed.
S47: When the writing is completed, the communications control unit 3 transmits a response to the write command to the external device 100.
S48: The control unit 2 transmits a write command to the communication control unit 3 after a predetermined time has elapsed.
S 49 : The communication control unit 3 having received the write command writes the recovery information into the second non-volatile memory 31 .
S50: When the writing of the recovery information is completed, the communications control unit 3 transmits a response to the write command to the control unit 2.
S51: When the control unit 2 receives the response, it transitions to the stop mode.
When the communication between the communication circuit 30 and the external device 100 is NFC, the power required for the communication between the external device 100 and the communication circuit 30 can be provided by the electromotive force generated in the NFC receiving coil by reception from the external device 100. Therefore, the communication between the communication circuit 30 and the external device 100 has almost no effect on the voltage drop of the battery 4.

Next, referring to FIG. 10, we will explain the operation of the electronic watch 1 when communication with the external device 100 is in progress when the save operation is started.

S61: The control unit 2 determines that the condition for switching to the stop mode is met. The control unit 2 stops timing and stops the movement of the hands.
S<b>62 : The external device 100 transmits a write command to the first non-volatile memory 21 to the communication control unit 3 .
S<b>63 : The communication control unit 3 transmits a write command to the control unit 2 to write data to the first non-volatile memory 21 .
S64: The control unit 2 writes the data sent from the external device 100 to the first non-volatile memory 21. If the data from the external device 100 is time correction data, the control unit 2 corrects the watch's internal time. The control unit 2 also moves the hands 6 to a position corresponding to the corrected watch's internal time. In other words, the control unit 2 corrects the return information based on the data from the external device 100.
S65: When the execution of the write command is completed, the control unit 2 transmits a response to the write command to the communication control unit 3.
S66: The communication control unit 3 transmits a response to the write command to the external device 100.
S67: The control unit 2 transmits a write command to the communication control unit 3. The recovery information transmitted at this time is the corrected recovery information.
S<b>68 : The communication control unit 3 , which has received the write command, writes the recovery information into the second non-volatile memory 31 .
S69: When the writing of the recovery information is completed, the communications control unit 3 transmits a response to the write command to the control unit 2.
S70: When the control unit 2 receives the response, it transitions to the stop mode.

As described above, the electronic watch 1 of this embodiment has a first non-volatile memory 21 and a control unit 2 that controls the time display, a second non-volatile memory 31 arranged outside the control unit 2, and a battery 4. The power consumption when the second non-volatile memory 31 stores data is less than the power consumption when the first non-volatile memory 21 stores data.

When the voltage V of the battery 4 drops, the control unit 2 transitions to a stop mode in which the operation of the control unit 2 is stopped. When transitioning to the stop mode, the control unit 2 stores recovery information in the second non-volatile memory 31. The recovery information is information that the control unit 2 refers to when resuming operation. The electronic watch 1 according to this embodiment stores the recovery information in the second non-volatile memory 31, which has a relatively low power consumption, so that the recovery information can be saved in the non-volatile memory while suppressing a drop in the battery voltage.

The second non-volatile memory 31 in this embodiment is a memory included in the communication control unit 3 for wireless communication. While the control unit 2 is storing the recovery information in the second non-volatile memory 31, it prohibits the communication control unit 3 from responding to commands sent via wireless communication, or it delays the execution of the command in the communication control unit 3. Therefore, the electronic watch 1 in this embodiment can more reliably store the recovery information.

The electronic watch 1 may have a digital display in addition to the hands 6 as a time display means. The electronic watch 1 may also be a digital electronic watch that does not have hands 6 and displays the time using a digital display.

The communication method used by the communication control unit 3 is not limited to NFC. The communication method may be, for example, Bluetooth (registered trademark) or Wi-Fi. The second non-volatile memory 31 is not limited to a memory arranged in the communication control unit 3. The second non-volatile memory 31 may be a memory of a sensor mounted on the electronic watch 1. The second non-volatile memory 31 may be implemented as an independent memory on the circuit board 15, etc.

The return information may be stored outside the electronic watch 1 by wireless communication. For example, the control unit 2 may transmit the return information to the external device 100 by short-range wireless communication. The external device 100 may store the acquired return information in a server on the cloud. The control unit 2 may transmit the return information to a server on the cloud by wireless communication such as Wi-Fi.

The electronic watch 1 may store the same data in both the first non-volatile memory 21 and the second non-volatile memory 31 and periodically verify the data. For example, serial data is written to the first non-volatile memory 21 and the second non-volatile memory 31 at the time of shipment from the factory. The control unit 2 periodically reads data from the first non-volatile memory 21 and the second non-volatile memory 31 and performs verification. The verification may be performed regardless of the stop mode. If the two pieces of data do not match, the control unit 2 notifies the user that a failure mode has occurred. The control unit 2 may also determine that a failure has occurred if the two pieces of data do not match after multiple consecutive verifications.

[First Modification of the Embodiment]
A first modified example of the embodiment will be described. The first modified example of the embodiment is different from the above embodiment in that, when transitioning to the stop mode, the control unit 2 stores part of the return information in the first non-volatile memory 21.

More specifically, the control unit 2 stores the first information from the recovery information in the first non-volatile memory 21. The first information is information with a high priority among the information referenced when the electronic watch 1 resumes operation. The first information is information for preventing the position of the hands 6 from deviating from a reference position, for example, information for resuming the time display by the hands 6 in the electronic watch 1. The first information includes, for example, a BAT flag, motor steering, and hand position. The first information may also include time information. By storing the first information in the first non-volatile memory 21, the main functions of the electronic watch 1 can be resumed more reliably. For example, it is possible to resume the time display function even if serial communication with the communication control unit 3 is interrupted.

The control unit 2 stores all items of the return information in the second non-volatile memory 31, as in the above embodiment. This makes it possible to store the return information while suppressing power consumption. The storage operation according to the first modified example of the embodiment will be described with reference to FIG. 11.

S71: The control unit 2 determines that the condition for switching to the stop mode is met. The control unit 2 stops timekeeping and stops the movement of the hands.
S72: The control unit 2 writes the first information to the first non-volatile memory 21.
S73: The control unit 2 transmits a write command to the communication control unit 3. This write command instructs writing of recovery information.
S74: The communication control unit 3 that has received the write command writes all of the recovery information data into the second non-volatile memory 31.
S75: When the communication control unit 3 completes writing the recovery information, it transmits a response to the write command to the control unit 2.
S76: When the control unit 2 receives the response, it transitions to the stop mode.
The order of steps S72 and S74 may be reversed. That is, the control unit 2 may write the recovery information to the second nonvolatile memory 31 and then write the first information to the first nonvolatile memory 21. The control unit 2 transitions to the stop mode when writing of information to both the first nonvolatile memory 21 and the second nonvolatile memory 31 is completed.

Next, a return operation according to a first modified example of the embodiment will be described with reference to FIG.
S81: The control unit 2 determines that the condition for returning from the stop mode is met.
S82: The control unit 2 transmits a read command to the communication control unit 3. This read command instructs the reading of all data of the return information.
S83: The communication control unit 3 that has received the read command reads all data of the recovery information from the second non-volatile memory 31.
S84: The communication control unit 3 transmits the read recovery information to the control unit 2 as a response to the read command.
S85: The control unit 2 recovers from the stop mode based on the recovery information acquired from the communication control unit 3, and transitions to the normal mode.

Referring to FIG. 13, a recovery operation when recovery information cannot be acquired from communication control unit 3 will be described.
S91: The control unit 2 determines that the condition for returning from the stop mode is met.
S92: The control unit 2 transmits a read command to the communication control unit 3. This read command instructs the reading of all data of the return information.
S93: If the maximum waiting time has elapsed without receiving a response from the communication control unit 3, the control unit 2 determines that a timeout has occurred.
S94: The control unit 2 reads the first information from the first non-volatile memory 21.
S95: The control unit 2 returns from the stop mode based on the first information read from the first non-volatile memory 21, and transitions to the normal mode.

The items to be stored in the second non-volatile memory 31 may be the items of the recovery information excluding the first information. For example, in the write command of S73, the control unit 2 may transmit all the items of the recovery information excluding the first information to the communication control unit 3. In this case, in the recovery operation, the control unit 2 may first read the first information from the first non-volatile memory 21, and then read the remaining recovery information from the second non-volatile memory 31.

[Second Modification of the Embodiment]
A second modification of the embodiment will be described. The second modification of the embodiment differs from the above embodiment in that, when a clock stop event occurs, an event log is stored in the second non-volatile memory 31.

The operation of the electronic timepiece 1 according to the second modified example of the embodiment will be described with reference to FIG.
S101: The control unit 2 detects the occurrence of an event. The content of the event is, for example, a shift in the needle position of the pointer 6.
S102: The control unit 2 stores the event that has occurred in the RAM 22. The data to be stored is, for example, the number of times that the hand position has shifted.
S103: The control unit 2 detects the occurrence of a clock stop event. The content of the event is, for example, a hand position detection error. A hand position detection error occurs, for example, when the hand position of the pointer 6 cannot be detected.
S104: The control unit 2 stores the event that has occurred in the RAM 22.
S105: The control unit 2 transmits a write command to the communication control unit 3. In this write command, the event log stored in the RAM 22 and the number of times the event has occurred are transmitted.
S 106 : The communication control unit 3 that has received the write command writes the data related to the event into the second non-volatile memory 31 .
S107: When the communication control unit 3 completes writing the event-related data, it transmits a response to the write command to the control unit 2.
S108: When the control unit 2 receives the response, it transitions to the stop mode.

The user can check the event log stored in the second non-volatile memory 31 using the external device 100. The procedure for checking the event log will be described with reference to Fig. 15 .
S111: The user starts an application program in the external device 100 that is linked to the electronic watch 1.
S112: The user selects to read a log in an application program.
S113: The user brings the external device 100 close to the electronic watch 1 in accordance with the instructions of the application program.
S114: The application program transmits a read command to the communication control unit 3 via NFC communication.
S115: The communication control unit 3 that has received the read command reads the event log from the second non-volatile memory 31. The communication control unit 3 transmits the event log to the external device 100 as a response to the read command. The external device 100 stores the received event log in the storage unit 120.

Even if the control unit 2 is stopped or the voltage of the battery 4 is low, the external device 100 and the communication control unit 3 can perform short-distance wireless communication. Therefore, the cost required to read the event log is reduced compared to when the event log is stored in the first non-volatile memory 21. The user can receive advice at the manufacturer's directly managed store based on the acquired event log. In addition, the user can receive advice or request an estimate of repair costs by transmitting the event log to the support center.

The contents disclosed in the above embodiments and variations can be implemented in any suitable combination.

REFERENCE SIGNS LIST 1 Electronic watch 2 Control unit 3 Communication control unit 4 Battery 5 Motor 6 Hands 7 Wheel train 10: Exterior case 10a: Main body 10b: Bezel 10c: Back cover 11: Dial 12: Windshield 13: Solar panel 14: Magnetic sheet 15: Circuit board 20: Control circuit 21: First non-volatile memory 22: RAM
30: communication circuit; 31: second non-volatile memory; 32: antenna;
32a: Board, 32b: Antenna wire, 33: Connection member, 61: Hour hand, 62: Minute hand, 63: Second hand, 64: Date indicator

Claims (4)

A control unit having a first non-volatile memory and controlling a time display;
A second non-volatile memory disposed outside the control unit;
a battery that supplies power to the control unit and the second nonvolatile memory;
A communication circuit for wirelessly communicating with an external device;
Equipped with
a power consumption when the second nonvolatile memory stores data is smaller than a power consumption when the first nonvolatile memory stores the data;
When the voltage of the battery drops, the control unit transitions to a stop mode in which the operation of the control unit is stopped,
The control unit sends a command to the communication circuit when transitioning to the stop mode,
The communication circuit that has received the command controls the second non-volatile memory to store recovery information, which is information that the control unit refers to when resuming operation.
An electronic watch characterized by: the return information includes first information for restarting the display of time by the hands,
The electronic watch according to claim 1 , wherein the control unit, when transitioning to the stop mode, stores the first information in the first non-volatile memory and stores the return information in the second non-volatile memory. the second non-volatile memory is a memory included in a communication control unit for wireless communication,
The electronic watch as described in claim 1 or 2, wherein the control unit prohibits the communication control unit from responding to commands via wireless communication or delays execution of the commands in the communication control unit while the recovery information is being stored in the second non-volatile memory. A control unit having a first non-volatile memory and controlling a time display;
A second non-volatile memory disposed outside the control unit;
a battery that supplies power to the control unit and the second nonvolatile memory;
Equipped with
a power consumption when the second nonvolatile memory stores data is smaller than a power consumption when the first nonvolatile memory stores the data;
When the voltage of the battery drops, the control unit transitions to a stop mode in which the operation of the control unit is stopped,
When the control unit transitions to the stop mode, the control unit stores, in the second nonvolatile memory, return information that is information to be referenced when the control unit resumes operation;
the second non-volatile memory is a memory included in a communication control unit for wireless communication,
The control unit prohibits the communication control unit from responding to a command via wireless communication or delays execution of the command in the communication control unit while the recovery information is being stored in the second non-volatile memory.
An electronic watch characterized by:

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