Patent ID: 12217041

DETAILED DESCRIPTION

FIG.1is a diagram for describing first through third portable devices according to an example embodiment.

Referring toFIG.1, a first portable device100may include a connection pin T1. The first portable device100may transmit data or a command signal to a second portable device200via the connection pin T1. Also, the first portable device100may receive data or a response signal from the second portable device200via the connection pin T1. The connection pin T1of the first portable device100may be connected to a connection pin T2of the second portable device200. The term “connected” described in the present specification may refer to a direct contact or indirect contact between the plurality of connection pins T1and T2. The first portable device100may transmit data or a notification signal to a third portable device300wirelessly. Also, the first portable device100may wirelessly receive a request signal from the third portable device300. The first portable device100may be a wearable device such as smart glasses, a smart watch, a smart band, or wireless earphones (or earbuds).

The second portable device200may include the connection pin T2and an external voltage pin Tin. The second portable device200may receive an external voltage Vin via the external voltage pin Tin. For example, the second portable device200may receive the external voltage Vin corresponding to an alternating current source, which is a power source for homes, through the external voltage pin Tin. In another implementation, the second portable device200may receive the external voltage Vin from another power supply unit (e.g., a computer or an auxiliary battery) through the external voltage pin Tin. In another implementation, the second portable device200may receive the external voltage Vin wirelessly from the outside. The second portable device200may be, for example, a charging device.

The first portable device100and the second portable device200may perform power line communication (PLC). PLC refers to a communication technique for transmitting power and data via a power line.

The third portable device300may perform wireless communication with the first portable device100. The wireless communication may be, for example, Bluetooth. The third portable device300may be a computing device, for example, a laptop computer, a tablet PC, or a mobile phone (or smartphone).

The first portable device100may be referred to as an external device with respect to the second portable device200and the third portable device300. Likewise, the second portable device200may be referred to as an external device with respect to the first portable device100and the third portable device300. The third portable device300may be referred to as a host with respect to the first portable device100and the second portable device200. A “portable device” described in the present specification may be referred to as a “mobile equipment,” “a portable equipment,” “a mobile device,” or the like.

FIG.2is a diagram for describing first and second portable devices according to an example embodiment, in further detail.

Referring toFIG.2, the first portable device100and the second portable device200may be connected to each other via first and second connection pins T1_1, T1_2, T2_1, and T2_1. As the first portable device100and the second portable device200are connected to each other, a power line may be implemented between the first connection pin T1_1of the first portable device100and the first connection pin T2_1of the second portable device200and a power line may be implemented between the second connection pin T1_2of the first portable device100and the second connection pin T2_2of the second portable device200. The first portable device100and the second portable device200may perform PLC via the power lines. A power line implemented between the first connection pin T1_1of the first portable device100and the first connection pin T2_1of the second portable device200may be a line through which a positive voltage or current is transferred. Also, a power line implemented between the second connection pin T1_2of the first portable device100and the second connection pin T2_2of the second portable device200may be a line through which a negative voltage or current is transferred. However, the number of power lines and voltages and currents transferred via each power line may be varied. As the first and second portable devices100and200perform power line communication (PLC) via the first and second connection pins T1_1, T1_2, T2_1, and T2_1, there is no need to additionally provide connection pins for performing data communication, and thus, the manufacturing costs may be reduced, and the sizes of the first and second portable devices100and200may be reduced.

The first portable device100may include a power line communication module110, a controller120, a power management integrated circuit130, a battery140, a wireless communication module150, and a memory module160.

The power line communication module110may receive power from the second portable device200in response to the control by the controller120. The power line communication module110may transmit or receive data to or from the second portable device200in response to the control by the controller120. The power line communication module110may modulate a current signal to be transmitted to the second portable device200. The power line communication module110may demodulate a voltage signal received from the second portable device200.

The power line communication module110may transmit an update initiation signal to the second portable device200. The update initiation signal may be a signal commanding initiation of a firmware update. Firmware update may refer to update of firmware of the second portable device200.

After the update initiation signal is transmitted to the second portable device200, the power line communication module110may transmit an erase command signal to the second portable device200. The erase command signal may be a signal commanding to erase firmware data stored in the second portable device200.

After the erase command signal is transmitted to the second portable device200, the power line communication module110may transmit firmware data to the second portable device200. The firmware data may include data including information about firmware of the second portable device200and may be referred to as a firmware image.

The power line communication module110may transmit an update end signal to the second portable device200according to a response signal from the second portable device200. The update end signal may be a signal commanding to end firmware update. This will be described in more detail later with reference toFIG.3.

The controller120may control the overall operation of the first portable device100. The controller120may control the power management integrated circuit130to perform a charging operation based on power received from the second portable device200. The controller120may control the power line communication module110to perform a communication operation on the second portable device200. The controller120may control the wireless communication module150to perform a communication operation with respect to the third portable device300. The controller120may control the memory module160to store data received from the second portable device200. The controller120may include a micro control unit (MCU), a processor such as a central processing unit (CPU), etc.

The power management integrated circuit130may charge the battery140by using different charging methods according to a charging state of the battery140. For example, the power management integrated circuit130may charge the battery140by using a pre-charging method, a constant-current method, a constant-voltage method, or a trickle charging method, according to the increase in a charging voltage of the battery140. The power management integrated circuit130may charge the battery140by using the pre-charging method when the battery140is over-discharged. The power management integrated circuit130may charge the battery140by using the constant current method and the constant voltage method when the battery140is in a normal state. The power management integrated circuit130may charge the battery140by using the trickle method when the battery140is in a fully-charged state.

The battery140may be charged with power supplied from the power management integrated circuit130. A charging state of the battery140may include an over-discharged state, a normal state, and a fully-charged state. The battery140may be implemented using, e.g., a rechargeable secondary battery or a fuel cell.

The wireless communication module150may perform wireless communication with the third portable device300. To perform a firmware update, the wireless communication module150may receive firmware data for execution in the second portable device200, from the third portable device300, and provide the received firmware data to the controller120. The wireless communication module150may receive a signal for requesting a firmware update from the third portable device300, and provide the received signal to the controller120.

The power line communication module110may receive another response signal from the second portable device200, and the controller120may generate a notification signal for requesting display of a message on the third portable device300, in response to the other response signal. The wireless communication module150may transmit the notification signal to the third portable device300.

The memory module160may include a volatile memory161and a non-volatile memory162. The volatile memory161may include dynamic random access memory (DRAM), static random access memory (SRAM), or the like. The non-volatile memory162may store data or signals regardless of whether power is supplied or not. The non-volatile memory162may include, e.g., a NAND flash memory, NOR flash memory, or the like.

The memory module160may store data. The memory module160may store first firmware data executed in the first portable device100. The memory module160may store second firmware data executed in the second portable device200. The volatile memory161may temporarily store a signal received from the second portable device200and data transmitted by the third portable device300, only during a power receiving period. The second firmware data executed in the second portable device200may be stored in the non-volatile memory162before the signal for firmware update described above is transmitted to the first portable device100.

The second portable device200may include a power line communication module210, a controller220, a power management integrated circuit230, a battery240, a display250, and a memory module260. The second portable device200may include external voltage pins Tin_1and Tin_2, via which an external voltage Vin may be received from the outside. For example, the external voltage pins Tin_1and Tin_2may receive the external voltage Vin from an alternating current source, which is a power source for homes or other power supply units (e.g., a computer or an auxiliary battery). The second portable device200may also receive the external voltage Vin wirelessly from the outside.

The power line communication module210may transmit power to the first portable device100in response to the control by the controller220. The power line communication module210may receive data (e.g., firmware data) or a signal (e.g., an update initiation signal, an erase signal, or an update end signal) from the first portable device100in response to the control by the controller220. The power line communication module210may transmit a response signal to the first portable device100in response to the control by the controller220. The power line communication module210may modulate a voltage signal to be transmitted to the first portable device100. The power line communication module210may demodulate a current signal received from the first portable device100.

The controller220may control the overall operation of the second portable device200. For example, the controller220may control the power management integrated circuit230such that power is supplied to the second portable device200. The controller220may control the power line communication module210to perform a communication operation on the first portable device100. The controller220may control the display250to perform a display operation of displaying a charge amount of the battery240, a state of the second portable device200, or the like. The controller220may control the memory module260to store data received from the first portable device100. The controller220may include a processor such as an MCU or a CPU.

The controller220may load firmware data from the memory module260when the second portable device200is booted, and execute a user mode based on the firmware data.

The controller220may enter a firmware update mode from the user mode in response to an update initiation signal received by the power line communication module210. In the firmware update mode, the controller220may perform a validity check based on updated firmware data provided by the first portable device100. The validity check may be a check on whether firmware data provided by the first portable device100is valid data. The validity check may be, for example, a cyclic redundancy check.

The controller220may control the memory module260such that updated firmware data is stored in the memory module260according to a result of the validity check. The updated firmware data may be stored in a non-volatile memory262included in the memory module260, and firmware data that was previously stored in the non-volatile memory262may be processed as invalid.

The controller220may monitor whether the first and second connection pins T2_1and T2_2are connected to the first connection pins T1_1and T1_2of the first portable device100, respectively, and may generate a response signal for notifying release of the connection pins T1_1, T1_2, T2_1, and T2_2. The power line communication module210may transmit the response signal to the first portable device100. In response to the response signal, the first portable device100may transmit, to the third portable device300, a notification signal for requesting display of a message on the third portable device300.

The controller220may compare a charge amount of the battery240with a preset reference amount, and may control the power management integrated circuit230to block the external voltage Vin based on whether the charge amount of the battery240is greater than the preset reference amount.

The power management integrated circuit230may charge the battery240based on the external voltage Vin received from the outside. The power management integrated circuit230may generate a charging voltage to be provided to the battery240, based on the external voltage Vin. The power management integrated circuit230may include a converter (not shown) generating a conversion voltage from the external voltage Vin revived from the outside via the external voltage pins Tin_1, Tin_2or from a battery voltage of the battery240. The converter may be a DC-DC converter. The converter may be a step-up converter converting a relatively low external voltage Vin or a battery voltage into a higher conversion voltage (e.g., a boost converter), or a step-down converter converting a relatively high external voltage Vin or a battery voltage into a lower conversion voltage (e.g., a buck converter).

The battery240may be charged based on a charging voltage supplied from the power management integrated circuit230.

The memory module260may include a volatile memory261and the non-volatile memory262, like the memory module160included in the first portable device100.

In the present example embodiment, the first portable device100transmitting firmware data to the second portable device200is described, but the second portable device200may be implemented to transmit firmware data of firmware of the first portable device100via PLC.

FIG.3is a diagram for describing a first operating method of first through third portable devices, according to an example embodiment.

Referring toFIG.3, a first portable device PD1illustrated inFIG.3may correspond to the first portable device100illustrated inFIG.1, and a second portable device PD2illustrated inFIG.3may correspond to the second portable device200illustrated inFIG.1, and a third portable device PD3illustrated inFIG.3may correspond to the third portable device300illustrated inFIG.1.

In the present example embodiment, in operation S10, the third portable device PD3transmits a request signal to the first portable device PD1via wireless communication. The request signal generated by the third portable device PD3may be a signal for requesting to update firmware of the second portable device PD2. Referring toFIG.2, for example, a user may command initiation of a firmware update in an application or software of the third portable device PD3, and the third portable device PD3may transmit a request signal to the first portable device100via wireless communication, and the wireless communication module150included in the first portable device100may receive the request signal from the third portable device PD3.

In operation S20, the first portable device PD1transmits an update initiation signal to the second portable device PD2in response to the request signal. Referring toFIG.2, for example, the controller120included in the first portable device100may generate an update initiation signal in response to a request signal, and provide the update initiation signal to the power line communication module110, and may control the power line communication module110to transmit the update initiation signal to the second portable device200via PLC.

In operation S30, the second portable device PD2changes from a user mode to a firmware update mode in response to the update initiation signal. Referring toFIG.2, for example, the controller220included in the second portable device200may enter the firmware update mode in response to an update initiation signal provided from the power line communication module210.

In operation S21, the first portable device PD1provides an erase command signal after the update initiation signal is transmitted. Referring toFIG.2, for example, the controller120may generate an erase command signal, provide the same to the power line communication module110, and control the power line communication module110to transmit the erase command signal. The power line communication module110may transmit the erase command signal to the second portable device PD2before the firmware data is provided to the second portable device200.

In operation S31, the second portable device PD2erases previously stored firmware data in response to the erase command signal. Referring toFIG.2, for example, the power line communication module210may receive the erase command signal after the update initiation signal is received, and provide the erase command signal to the controller220. In response to the erase command signal, the controller220may control the non-volatile memory262to erase firmware data stored in the non-volatile memory262.

In operation S22, the first portable device PD1transmits the updated firmware data to the second portable device PD2after the erase command signal is transmitted. Referring toFIG.2, for example, the power line communication module110may transmit the updated firmware data to the second portable device200. In this case, the firmware data to be transmitted to the second portable device200may be divided or split and transmitted in units of data packets having a first size. For example, firmware data to be transmitted to the second portable device200may be divided into 1-byte data packets, and the 1-byte data packets may be sequentially transmitted to the second portable device200.

In operation S32, the second portable device PD2temporarily stores the firmware data that is divided or split and transmitted in units of data packets. Referring toFIG.2, for example, the controller220may control the volatile memory261to temporarily store a 1-byte data packet received through the power line communication module210, in the volatile memory261.

In operation S23, the first portable device PD1determines whether a predefined number of data packets have been transmitted to the second portable device PD2. The predefined number may be, for example, 8, and when 8 data packets are transmitted to the second portable device PD2(operation S23, YES), the first portable device PD1transmits first check data regarding a cyclic redundancy check performed on the data packets, to the second portable device PD2(operation S24). That is, each time 8-byte data packets are transmitted to the second portable device PD2, the first check data may be transmitted to the second portable device PD2. On the other hand, when 8 data packets are not transmitted to the second portable device PD2(operation S23, NO), operation my return to operation S22.

In operation S33, the second portable device PD2generates second check data based on the temporarily stored firmware data.

Then, in operation S34, the second portable device PD2checks whether a validity check, that is, a cyclic redundancy check, is a pass, by using the first check data and the second check data). Whether the cyclic redundancy check is a pass may be determined based on whether the first check data and the second check data match. The controller220may control the non-volatile memory262to store updated firmware data in the non-volatile memory262according to a result of the validation check. According to this, by checking whether there are errors in a data packets, errors in firmware data may be reduced.

When a result of the cyclic redundancy check is a pass (operation S34, YES), in operation S35the second portable device PD2performs a write operation. The write operation may be an operation of storing data in a non-volatile memory. Referring toFIG.2, for example, in response to a result of the validation check, the result being a pass, the controller220may control the non-volatile memory262to store updated firmware data by transmitting 8-byte data packets and a write command/address to the non-volatile memory262.

On the other hand, when the result of the cyclic redundancy check is a fail (operation S34, NO), the second portable device PD2releases the temporarily stored firmware data in operation S36. The release of the temporarily stored firmware data may be an operation that erases or flushes data stored in a volatile memory. Referring toFIG.2, for example, in response to the result of the validation check being a fail, the controller220may control the volatile memory261to delete 8-byte data packets temporarily stored in the volatile memory261.

In operation S37, the second portable device PD2transmits a response signal indicating a pass or a fail of the cyclic redundancy check to the first portable device PD1. Referring toFIG.2, for example, the controller220may control the power line communication module210to transmit a response signal indicating that the result of the validation check is a fail, to the first portable device100.

In operation S25, the first portable device PD1checks whether the response signal is a pass.

When the response signal indicates a fail (operation S25, NO), the operation returns to operation S22and firmware data is divided and transmitted in units of 1 byte-data packets.

On the other hand, when the response signal indicates a pass (operation S25, YES), the first portable device PD1determines whether all firmware data is transmitted in operation S26. Until all the firmware data is transmitted, the above-described operations S22to S25and S32to S37are performed.

When the response signal indicates a pass (operation S25, YES), the first portable device PD1transmits an update end signal to the second portable device PD2in operation S27. Referring toFIG.2, for example, when the response signal indicates a pass, the controller120may generate an update end signal and provide the same to the power line communication module110, and control the power line communication module110to transmit the update end signal.

On the other hand, when the response signal indicates a fail (operation S25, NO), the operation returns to operation S22and the controller120may control the power line communication module110to transmit the firmware data stored in the non-volatile memory162back to the second portable device200. Also when the firmware data is transmitted again, the firmware data may be transmitted in units of 1 byte data packets. Meanwhile, the power line communication module210may receive the firmware data again after the response signal is transmitted to the first portable device100.

In operation S38, the second portable device PD2resets with the stored firmware data, i.e., new firmware data, in response to the update end signal, and executes a user mode.

According to the above, firmware of a portable device may be updated simply and quickly compared to firmware update done by visiting a service center or through a separate compile function, such as, zig.

FIG.4is a diagram for describing a second operating method of first through third portable devices, according to an example embodiment.

Referring toFIG.4, operations S100, S200, and S300are respectively the same as operations S10, S20, and S30described above, and thus, the description thereof will be omitted.

In operation S310, the second portable device PD2monitors whether a connection pin provided in the second portable device PD2and a connection pin provided in the first portable device PD1are connected to each other. Referring toFIG.2, for example, the controller220included in the second portable device200may monitor whether the first and second connection pins T2_1and T2_2of the second portable device200and the first and second connection pins T1_1and T1_2of the first portable device100are respectively in contact with each other.

When the connection between the connection pins is abnormal or bad (operation S310, NO), the second portable device PD2transmits a first response signal to the first portable device PD1in operation S320. In response to the first response signal, the first portable device PD1transmits a first notification signal indicating that the contact between the connection pins is bad, to the third portable device PD3in operation S210. The third portable device PD3may display a first message in response to the first notification signal. For example, the first message may indicate “reconnect the connection pins to complete firmware update” or the like.

On the other hand, when the connection of the connection pins is normal (operation S310, YES), the second portable device PD2monitors whether a charge flag has a first set value in operation S330. The charge flag may indicate whether the power management integrated circuit230receives the external voltage Vin and charges the battery240. The charge flag may have a first set value (e.g., true) or a second set value (e.g., false). The charge flag having the first set value may indicate that the power management integrated circuit230is charging the battery240. The charge flag having the second set value may indicate that charging of the battery240is stopped. The first portable device PD1may stop a wireless communication operation on the third portable device PD3. For example, the first portable device PD1may turn off Bluetooth of the third portable device PD3. As the wireless communication is stopped, the influence of noise by the third portable device PD3may be reduced.

When the charge flag does not have the first set value (operation S330, NO), the second portable device PD2transmits a second response signal to the first portable device PD1in operation S340. In response to the second response signal, the first portable device PD1transmits a second notification signal indicating that firmware is being updated, to the third portable device PD3in operation S220. The third portable device PD3may display a second message in response to the second notification signal. For example, the second message may indicate “updating firmware” or the like.

On the other hand, when the charge flag has the first set value (operation S330, YES), the second portable device PD2monitors whether a charge amount of the battery240is greater than a first reference amount in operation S350.

When the charge amount of the battery240is not greater than the first reference amount (operation S350, NO), the second portable device PD2displays battery information about the battery240, such as the charge amount, in operation S361. Referring toFIG.2, for example, the controller220may control the display250to display battery information.

When the charge amount of the battery240is greater than the first reference amount (operation S350, YES), the second portable device PD2sets a set value of the charge flag to the second set value in operation S362. Referring toFIG.2, for example, the controller220may control the power management integrated circuit230to stop a charging operation by setting the set value of the charge flag to the second set value. Accordingly, the amount of heat generated in the second portable device PD2may be reduced, and the influence of noise caused by the external voltage Vin during PLC may be reduced. Accordingly, the time for transmitting the firmware data may be shortened. The first portable device PD1may transmit a notification signal informing that the firmware update is to restart, to the third portable device PD3.

After each of operations S361and S362is performed, operation S310is performed again.

Referring again to operation S330, when the charge flag does not have the first set value (operation S330, NO), because the charge flag has the second set value, the charge amount of the battery240is reduced. After the second response signal is transmitted to the first portable device PD1, the second portable device PD2monitors whether the charge amount of the battery240is less than a second reference amount (operation S370). The first reference amount may be greater than the second reference amount.

When the battery charge amount is less than a second reference amount (operation S370, YES), the second portable device PD2sets the value of the charge flag to the first set value in operation S380. When the charge flag has the first set value, the battery240may be charged as described above.

On the other hand, when the the battery charge amount is not less than the second reference amount (operation S370, NO), the second portable device PD2transmits a third response signal to the first portable device PD1in operation S390.

In operation S240, the first portable device PD1transmits firmware data to the second portable device PD2in response to the third response signal.

In operation S400, the second portable device PD2performs a firmware update operation. The firmware update operation according to operation S400may indicate that operations S22to S25and S32to S37described above with reference toFIG.2are performed.

FIG.5is a diagram illustrating an example of structures of data and a response (ACK) signal transmitted between first and second portable devices.

Referring toFIG.5, a data structure may be divided into a preamble, a header, and data. Each of the preamble, header, and data may include a plurality of fields.

In an example embodiment, a period of a preamble may have five periods. In addition, as all of preamble signals are toggled in each period, all logic values of the preamble signals may have a value of “1.”

The header may include a start field, a header type field, and a header parity field. The start field may include one bit and may correspond to information indicating a start of data transmission. The header type field indicates a type of data and may include one or more bits (e.g., four bits). The header parity field is used to determine validity of transmitted header information and may include one bit.

The data may include a data message field, a data parity field, a data checksum field, and an end field. The data message field may include actual data having a plurality of bits. The data parity field is used to determine the validity of data and may include one bit. The data checksum field is used to detect errors in data and may include a plurality of bits. The end field is used to indicate an end of data transmission and may include one bit.

A header of an update initiation signal may be expressed as “0x1”, and data of the update initiation signal may be expressed as “0 x10.” A header of an erase command signal may be expressed as “0x1”, and the data of the erase command signal may be expressed as “0x44.” A header of a data packet may be expressed as “0xA.” A header of check data may be expressed as “0xF.” A header of an update end signal may be expressed as “0xE,” and data of the update end signal may be expressed as “0x10.”

In order to increase the reliability of data transmission/reception, the second portable device200may transmit the response signal ACK. The response signal ACK may be transmitted once after data reception. The response signal ACK may have a shorter field structure than data. Accordingly, the time for transmitting the response signal ACK may be shortened.

The response signal ACK may include a preamble, a start field, a header type field, and a header parity field. The preamble may be the same as that described above. The start field may include one bit and may correspond to information indicating a start of transmission of the response signal ACK. The header type field may include at least one bit (e.g., four bits) and may indicate a type of the response signal ACK. The header parity field may include one bit and may be transmitted to determine the validity of header information.

A response signal indicating a pass may be expressed as “0x55.” A response signal indicating a fail may be expressed as “0xFF.”

On the other hand, in transmission/reception of data or the response signal ACK, when expressing one bit, when there is a toggle within one data cycle, logic “1” may be represented, and when there is no toggle, logic “0” may be represented. Also, because the preamble period is a period in which a frequency and duty are detected, the frequency and duty are not to be changed within the preamble period until data transmission/reception is performed.

FIG.6is a diagram for describing a preamble period and a data period.

In describing the example embodiment illustrated inFIG.6, it is assumed that the first portable device100transmits data, and the second portable device200receives data.

Referring toFIG.6, before data is transmitted, the second portable device200may enter a preamble period, and the second portable device200may receive a preamble signal that is toggled at least once in the preamble period.FIG.2illustrates an example in which the preamble signal is toggled once, and the second portable device200may detect a frequency and duty of the preamble signal through the preamble signal that is toggled at least once.

As an example, when a duty ratio of the preamble signal is set to 1:1, the frequency (or cycle (T)) of the preamble signal is detected by detecting a logic high period or a logic low period of the preamble signal. The second portable device200may perform various setting operations related to data reception based on the detected frequency of the preamble signal. As an example, the cycle T of the preamble signal corresponds to a data period including one bit in a data transmission period, and the second portable device200may perform an internal setting operation to determine data in each data cycle according to the detected frequency.

Next, the second portable device200may determine data D1, D2, and D3based on a preset condition in each data cycle. As an example, a timing (or period) for determining whether toggling of a voltage signal (or an internal signal) exists in each data cycle in each data period may be set based on a duty of a preamble signal, and when the toggling of the voltage signal is present in each data period, data of logic high may be determined, whereas, when there is no toggling of the voltage signal, data of logic low may be determined.

FIG.3illustrates an example in which a preamble period includes a plurality of periods. WhileFIG.3illustrates an example in which a preamble period includes three periods and a preamble signal is transmitted in each period, various numbers of preamble signals may be transmitted.

A preamble signal may be transmitted to the second portable device200through a power line, and a signal applied to the power line before a preamble period may have an initial state. Thereafter, as the preamble period starts, a preamble signal may be transmitted in each of first to third periods, and the first to third periods have the same time period, and duties D of the preamble signals may be identical to each other. The second portable device200may detect a frequency and duty of the preamble signal, based on the preamble signal received in each of the first to third periods.

The frequency and duty of the preamble signal may be variously set, and a detection operation thereof may also be performed using various methods. For example, as preamble signals having the same frequency and duty are transmitted in each of the first to third periods, the frequency and duty of the preamble signals may be detected. Alternatively, at least one of a frequency and a duty of preamble signals in each of the first to third periods may be different from the other, and the second portable device200may calculate an average value of the frequencies and duties of the preamble signals in a plurality of periods to detect the frequencies and duties of the preamble signals.

An example of an operation of transmitting and detecting a preamble signal will be described as below.

The second portable device200transmitting power may provide a voltage signal, and a level of the voltage signal transmitted through the power line may swing at an appropriate level that does not affect an operation of the second portable device200that receives the power. The second portable device200may perform voltage modulation to provide a preamble signal, and the frequency (or cycle) of the preamble signal may have a value that is slower than a limit clock (e.g., system clock) of the second portable device200. For example, the frequency of the limit clock of the second portable device200may be 20 times or more fast than the frequency of the preamble signal.

Although an initial state before the preamble period is shown as logic low, the preamble signal may be toggled once in each of a plurality of periods of a preamble period. Also, the second portable device200may perform a voltage modulation operation such that duties of preamble signals in a plurality of periods are the same. The first portable device100may analyze the preamble signal by using the limit clock and detect a frequency (or cycle) and duty of the preamble signal by using the analyzed preamble signal.

FIG.7is a diagram for describing modulation of signals transmitted between first and second portable devices, according to an example embodiment.

Referring toFIG.7, a current signal Ic may be a signal transmitted by the first portable device100to the second portable device200via PLC. A voltage signal Vc may be a signal transmitted by the second portable device200to the first portable device100via PLC.

A first communication period ETC may be a period in which the first portable device100modulates the current signal Ic to transmit firmware data or check data to the second portable device200. The first communication period ETC may be divided into a firmware data transmission period FWTP and a check data transmission period CRCTP. A second communication period CTE may be a period in which the second portable device200modulates the voltage signal Vc to transmit a response signal to the first portable device100.

A logic level of the current signal Ic may be higher than a reference level ref. The current signal Ic may be modulated during the first communication period ETC. The modulated current signal Ic may be a signal in the form of a pulse having a certain logic level. During the first communication period ETC, each time the current signal Ic is modulated in the firmware data transmission period FWTP, firmware data of a 1 byte data packet may be transmitted to the second portable device200. Referring toFIG.7, for example, each of first through eighth current pulses CP1through CP8may correspond to a 1 byte-data packet with respect to firmware data. It may be understood that 8 byte-data packets are transmitted to the second portable device200cvia the first through eighth current pulses CP1through CP8. During the first communication period ETC, a ninth current pulse CP9may be formed in the check data transmission period CRCTP. The ninth current pulse CP9may correspond to check data.

Meanwhile, a logic level of the voltage signal Vc may be lower than the reference level ref. The voltage signal Vc may have a form of first through eighth pulses DP1through DP8by the current signal Ic modulated during the first communication period ETC. The voltage signal Vc may be modulated during the second communication period CTE. A voltage pulse VP in the second communication period CTE may correspond to a response signal.

FIG.8is a diagram for describing portable devices according to another example embodiment.

FIG.8illustrates first and second earbuds11and12, a cradle20for the first and second earbuds11and12, a power source30connected to the cradle20, and a host device40performing wireless communication with the first and second earbuds11and12.

Hereinafter, description of details regarding the example embodiment ofFIG.8provided above may be omitted.

Each of the first and second earbuds11and12may correspond to the first portable device100illustrated inFIG.1. The cradle20may correspond to the second portable device200illustrated inFIG.1. The host device40may correspond to the third portable device300illustrated inFIG.1.

The first and second earbuds11and12may perform wireless communication with the host device40, and output sound from a source signal received from the host device40. The first and second earbuds11and12may perform mutual wireless communication with each other. For example, the first and second earbuds11and12may perform mutual wireless communication for the purpose of synchronization, transferring of states, or the like. Each of the first and second earbuds11and12may include a battery that is charged by power supplied from the cradle20, and may efficiently and completely perform power line communication with the cradle20. Accordingly, in the first and second earbuds11and12, in addition to a pair of terminals for charging, an additional terminal for communicating with the cradle20may be omitted, and the first and second earbuds11and12and the cradle20may have a simple structure. In particular, due to the compact size of the first and second earbuds11and12and the cradle20, the simple structure of the first and second earbuds11and12and the cradle20may provide various advantages.

The cradle20may function as a charger of the first and second earbuds11and12and may be portable. For example, the cradle20may include a battery28, and may charge the first and second earbuds11and12from power provided by the battery28. In addition, the cradle20may include a third terminal T23and a fourth terminal T24to be connected to the power source30, and the first and second earbuds11and12may be charged with power provided by the power source30to the battery28. The cradle20may function as a case for the first and second earbuds11and12. For example, the cradle20may have an internal structure in which the first and second earbuds11and12are seated, and may include a cover covering the first and second earbuds11and12.

Referring toFIG.8, the cradle20may include a first modem21, a second modem22, a power management integrated circuit (PMIC)24, and the battery28.

The first modem21may perform power line communication with the first earbud11.

The second modem22may perform power line communication with the second earbud12.

The PMIC24may provide power (supplied from power provided from the power source30and/or the battery28) to the first and second earbuds11and12. For example, the power source30may provide a 5V DC voltage based on a universal serial bus (USB) interface, and the PMIC24may generate a voltage and/or a current for charging the battery28, from the 5V DC voltage, and generate a voltage and/or current for charging the first and second earbuds11and12.

The host device40may be any device that provides a source signal to the first and second earbuds11and12through wireless communication.

FIG.9is a diagram for describing portable devices according to another example embodiment. For convenience of description, an example embodiment will now be described by using only one power line PL.

Referring toFIG.9, a first portable device50may correspond to the first portable device100illustrated inFIG.1, the first earbud11illustrated inFIG.8, or the second earbud12illustrated inFIG.8. A second portable device60may correspond to the second portable device200illustrated inFIG.1or the cradle20illustrated inFIG.8.

The first portable device50may include a connection pin T1, a variable impedance circuit51, a controller52, a PLC modem53, a battery54, a PMIC55, and a wireless transceiver56. The variable impedance circuit51, the controller52, the PLC modem53, the battery54, the PMIC55, and the wireless transceiver56may be mounted on a printed circuit board. The PMIC55may manage power of the battery54.

The wireless transceiver56may perform wireless communication with a host device70. For example, the wireless transceiver56may include a Bluetooth module and may receive data from the host device70. The wireless transceiver56of the first portable device50may provide data received from the host device70to the second portable device60via power line communication.

The second portable device60may include a connection pin T2, an external voltage pin Tin, a variable impedance circuit61, a controller62, a PLC modem63, a battery64, and a PMIC65. In another implementation, the second portable device60may include the variable impedance circuit61, the controller62, the PLC modem63, the battery64, and the PMIC65. The PMIC65may manage power of the battery64.

FIG.10is a diagram for describing portable devices according to another example embodiment.

Referring toFIG.10, a first portable device80may correspond to the first portable device100illustrated inFIG.1, the first earbud11illustrated inFIG.8, the second earbud12illustrated inFIG.8, or the first portable device50illustrated inFIG.9. A second portable device90may correspond to the second portable device200illustrated inFIG.1, the cradle20illustrated inFIG.8, or the second portable device60illustrated inFIG.9.

The first portable device80may include a connection pin T1, a charging circuit81, a battery82, a power line communication module83, a control circuit84, and an impedance circuit85. The charging circuit81may be a linear charger, and may be implemented as a charging integrated circuit (IC). The control circuit84may enable the charging circuit81in a charging period, and may charge the battery82based on power received through a power line PL. Also, in a data reception period, the control circuit84may disable the charging circuit81, and the first portable device80may operate based on power of the battery82. The battery82may be charged based on power received in a data transmission period.

The second portable device90may include a connection pin T2, an external voltage pin Tin, a converter91, a battery92, a power line communication module93, and a control circuit94. The converter91may generate a voltage Vc converted from the external voltage Vin received through the external voltage pin Tin or from a voltage of the battery92. The converter91may include a switching regulator, and may include a boost converter and/or a buck converter and a buck-boost converter as a DC-DC converter. The converter91may charge the battery92based on the external voltage Vin.

The power line communication module83of the first portable device80may include a voltage demodulator83_1and a current modulator83_2, and may further include a current source (not shown). The current modulator83_2may perform current modulation under the control by the control circuit84. The current source may generate a modulated current signal (e.g., a current pulse), and the current signal may be output through the connection pin T1. The voltage demodulator83_1may demodulate a voltage signal received through the connection pin T1and provide the demodulated signal to the control circuit84.

The power line communication module93of the second portable device90may include a current demodulator93_1and a voltage modulator93_2. The control circuit94may control the current demodulator93_1and the voltage modulator93_2. The voltage modulator93_2may generate a modulated voltage signal under the control by the control circuit94, and the voltage signal may be output through the connection pin T2. The voltage modulator93_2may include a linear regulator, such as a low drop-out (LDO) regulator. The current demodulator93_1may demodulate a current signal received through the connection pin T2and provide the demodulated signal to the control circuit94.

FIG.11is a diagram for describing portable devices according to another example embodiment.

Referring toFIG.11, an earbud410may correspond to the first portable device100illustrated inFIG.1, and a cradle420may correspond to the second portable device200illustrated inFIG.1.

The earbud410may include a control circuit411, a voltage demodulator412, and a current modulator413. The voltage demodulator412may include a filter412_1and an amplifier412_2.

The cradle420may include a control circuit421, an analog-to-digital converter (ADC)422, and an LDO regulator423. The ADC422may perform current demodulation. The LDO regulator423may perform voltage modulation.

In the earbud410, the filter412_1of the voltage demodulator412may remove noise by blocking a specific frequency component of a voltage signal received through the power line PL, and provide the filtered voltage signal to the amplifier412_2. The amplifier412_2may generate a signal having a logic high level or a logic low level by amplifying the voltage signal and provide the same to the control circuit411. The control circuit411may identify the information transmitted by the cradle420based on the signal received from the amplifier412_2, and by controlling the current modulator413to transmit the information to the cradle420, the control circuit411may generate a modulated current signal that is transmitted through the power line PL.

In the cradle420, the ADC422may generate a digital signal from a current signal received through the power line PL and provide the same to the control circuit421. The control circuit421may identify information transmitted by the earbud410based on the digital signal. By controlling the LDO regulator423, the control circuit421may generate a modulated voltage signal transmitted through the power line PL.

FIG.12is a diagram for describing portable devices according to another example embodiment.

Referring toFIG.12, the first portable device100is the same as described above.

Each of a first pin P1of the first portable device100and a second pin P2of a second portable device500may be communication pins formed separately from the connection pin T1, a pogo pin, or a power line.

The second portable device500may include a communication module510, a controller520, a power management integrated circuit530, a battery540, a display550, and a memory560. The power management integrated circuit530, the battery540, and the display550are the same as described above with reference toFIG.2.

The communication module510may include a Universal Asynchronous Receiver-Transmitter (UART) modem511and a PLC modem512. The UART modem511may perform UART communication with the first portable device100. The PLC modem512is the same as the PLC modem53illustrated inFIG.9.

The controller520may perform all of the operations of the controller220illustrated inFIG.2. The controller520may control the communication module510. For example, the controller520may control the UART modem511to perform UART communication. The controller520may load data stored in a boot code area561of the memory560and perform a firmware update. The firmware update is the same as described above with reference toFIGS.2,3, and4. The controller520may load data stored in the user area562in a user mode. The controller520may control the display550to display a charge amount of a battery in the user mode, and control the power management integrated circuit530to adjust power supplied from the outside and adjust heat generated in the second portable device200.

By way of summation and review, it would be advantageous to provide for enhanced data transmission and reception between wireless earphones and a charging case.

Embodiments may provide a portable device via which a firmware update may be conducted easily via power line communication (PLC), and an operating method of the portable device. Embodiments may also provide a portable device via which firmware data may be quickly transmitted, and an operating method of the portable device.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.