Portable electronic device and IC card

Abstract

To provide a portable electronic device that enables operation setting to be performed in accordance with a prescription for a processing time, and an IC card.SOLUTION: According to an embodiment, a portable electronic device includes an interface, a memory, and a processor. The interface communicates with an IC card processing device in a non-contact manner. The memory stores setting information that prescribes setting content of a frequency of an operation clock. The processor sets the frequency of the operation clock based on the frequency of the operation clock according to the intensity of a magnetic field generated in the interface and the setting information stored in the memory and executes processing for a command received from the IC card processing device through the interface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a portable electronic device and an IC card.

Background Art

[0002] Conventionally, in an IC card as a portable electronic device that communicates non - contactlessly, the power supplied varies according to the distance from the antenna of the reader / writer. This is because when the distance between the IC card and the reader / writer changes, the magnetic field strength received by the IC card changes. When the power as a power source of the IC card changes, the processing performance for commands changes.

[0003] For example, a conventional IC card sets an internal clock for operating an LSI as a processor to an optimal operating frequency (the maximum operable frequency) according to the magnetic field strength. Therefore, in a conventional IC card, the processing time for commands varies depending on the actual magnetic field strength received. That is, even for the same command, the difference between the processing time in a state where the magnetic field strength is weak and the processing time in a state where the magnetic field strength is strong may become large.

[0004] On the other hand, for reasons of operation, an IC card may have a specified allowable time (allowable difference time) for the difference between the fastest processing time and the slowest processing time in order to keep the variation in processing time within an allowable range. However, as the range of the magnetic field strength in which the IC card can operate becomes larger, the difference between the fastest and slowest processing times may become larger, making it difficult to keep within the allowable difference time. Also, when commands that require more complex processing than existing processes such as quantum - resistant cryptography, which is considered to be adopted in the future, are put into practical use, the difference between the fastest and slowest processing times becomes larger than that of existing commands, resulting in an even more difficult problem of keeping within the allowable difference time.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In order to solve the above problems, the present invention provides a portable electronic device capable of performing an operation setting according to a regulation for processing time, and an IC card.

Means for Solving the Problems

[0007] According to an embodiment, the portable electronic device includes an interface, a memory, and a processor. The interface communicates with the IC card processing device in a non-contact manner. The memory stores setting information that defines the setting content of the frequency of the operation clock. The processor sets the frequency of the operation clock based on the frequency of the operation clock corresponding to the intensity of the magnetic field generated in the interface and the setting information stored in the memory, and executes processing for commands received from the IC card processing device by the interface.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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BEST MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing a configuration example of an IC card 1 as a portable electronic device according to an embodiment. The IC card 1 as a portable electronic device according to the embodiment constitutes an IC card processing system together with an IC card processing device 2 as an external device. The IC card 1 is a portable electronic device that is activated (becomes operable) by the power supplied from the IC card processing device 2. The IC card 1 is also referred to as a smart card.

[0010] The IC card 1 as a portable electronic device according to this embodiment shall be a contactless IC card. The contactless IC card 1 receives radio waves from the IC card processing device 2 via an antenna as a communication interface, a demodulation circuit, etc., and generates and activates an operating power supply and an operating clock from the radio waves. For example, the contactless IC card 1 is an IC card compliant with the standard defined in ISO / IEC14443-3.

[0011] As shown in FIG. 1, the IC card 1 has a main body C. The main body C is formed in a card shape with plastic or the like. The IC card 1 has a module M inside the main body C. The module M is integrally formed with one or more IC chips Ca and an external interface (interface) for communication connected thereto, and is embedded in the main body C.

[0012] Note that the portable electronic device according to the embodiment is not limited to a card shape, and may be in the form of a booklet (for example, a notebook such as a passport) having the same configuration and processing functions as the IC card 1 described later. The portable electronic device formed in a booklet shape may be provided with the module M in the booklet-shaped main body C. Further, the portable electronic device according to the embodiment may be a portable electronic device (for example, a smartphone, a mobile phone, a tablet PC, a dongle, etc.) having the same configuration and processing functions as the IC card 1 described later. The portable electronic device as a portable electronic device may be provided with the module M inside the main body C.

[0013] In the configuration example shown in FIG. 1, the module M of the IC card 1 has a processor 11, a RAM 12, a ROM 13, an NVM (memory) 14, a communication control unit 15, an interface 16, etc. The IC chip Ca of the module M is composed of an LSI including a processor 11, a RAM 12, a ROM 13, and an NVM (memory) 14. The LSI as the IC chip Ca operates with an internal clock (operating clock) of a frequency set by the processing described later.

[0014] Processor 11 includes circuits that execute various processes. Processor 11 is, for example, a CPU (Central Processing Unit). Processor 11 controls the entire IC card 1. Processor 11 realizes various processing functions by executing programs stored in ROM 13 or NVM 14. For example, Processor 11 has a function of setting the frequency of an internal clock for operating the LSI that constitutes IC chip Ca. However, some or all of the various functions executed by Processor 11 described later may be realized by a hardware circuit.

[0015] RAM 12 is a volatile memory that functions as a working memory. Also, RAM 12 functions as a buffer for temporarily storing data being processed by Processor 11. For example, RAM 12 functions as a communication buffer for temporarily storing data transmitted and received to and from the IC card processing device 2 via the communication control unit 15 and the interface 16.

[0016] ROM 13 is a non-volatile memory that functions as a program memory. ROM 13 stores control programs and control data in advance. ROM 13 is incorporated into the IC card 1 with control programs and control data stored therein at the manufacturing stage. For example, ROM 13 stores a program for Processor 11 to execute processing according to commands received from the IC card processing device 2. The control programs and control data stored in ROM 13 are incorporated in advance according to the specifications of the IC card 1.

[0017] NVM 14 is a non-volatile memory capable of writing and rewriting data. NVM 14 is, for example, a storage unit composed of an EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory) or a flash ROM. Also, NVM 14 has a storage area in which some or all areas have tamper resistance and data can be securely stored.

[0018] In the NVM 14, programs and various data corresponding to the operation uses of the IC card 1 are written. In the NVM 14, program files or data files are defined, and programs and various data are written into those files. Further, the NVM 14 stores user data, data for network authentication for communicating with an external network, and application programs for executing various processes, etc.

[0019] Also, the NVM 14 stores setting information for setting the frequency of an internal clock (operation clock) as described later. The NVM 14 stores setting information for each command as setting information for setting the frequency of the internal clock. Also, the NVM 14 may store setting information for each application as setting information for setting the frequency of the internal clock. Also, the setting information stored in the NVM 14 may be written in the manufacturing process of the IC card 1, or may be written in the issuance process. Further, the NVM 14 may be configured to be able to write or update the setting information after the issuance process. Note that part or all of the setting information for each command or the setting information for each application may be written in the ROM 12 in the manufacturing process of the IC card 1.

[0020] The communication control unit 15 is connected to the interface 16. The interface 16 is an interface for communicating and connecting to an external device. The communication control unit 15 and the interface 16 constitute a communication unit. The communication control unit 15 and the interface 16 realize a communication function by a communication method corresponding to the interface of the IC card processing device 2. Also, the communication control unit 15 and the interface 16 may be configured to support a plurality of communication methods (communication protocols) whether it is contact communication or non-contact communication.

[0021] Also, in the IC card 1 which is a contactless IC card, the communication control unit 15 and the interface 16 constitute a communication unit that communicates with the card reader / writer of the IC card processing apparatus 2 in a contactless (wireless) manner. The interface 16 is constituted by an antenna that transmits and receives radio waves, and the communication control unit 15 is constituted by a modulation circuit for generating radio waves to be transmitted, a demodulation circuit for generating a signal from the received radio waves, and the like. Further, the communication control unit 15 that performs contactless communication controls communication in accordance with a communication method (communication protocol) such as Type A or Type B specified by the processor 11.

[0022] Also, when the IC card 1 which is a contactless IC card communicates with the IC card processing apparatus 2 (card reader / writer 24), it measures the intensity of the magnetic field generated between the interface 16 and the card reader / writer 24. That is, it is assumed that the processor 11 (or the communication control unit 15) of the IC card 1 has a function of specifying the magnetic field intensity generated in the interface 16. For example, the processor 11 acquires the magnetic field intensity by converting it from the signal level acquired from the interface 16.

[0023] The method by which the IC card 1 acquires the magnetic field intensity is not limited to a specific method. For example, the IC card 1 may further include a sensor for measuring the magnetic field intensity, and the processor 11 may acquire the magnetic field intensity detected by the sensor.

[0024] FIG. 2 is a block diagram schematically showing a configuration example of the IC card processing apparatus 2 according to the embodiment. In the configuration example shown in FIG. 2, the IC card processing apparatus 2 is a device (R / W) having a function of communicating with the IC card 1 via the card reader / writer 24. The IC card processing apparatus 2 may be, for example, a device in which the card reader / writer 24 is connected to a control device such as a personal computer (PC).

[0025] As shown in FIG. 2, the IC card processing apparatus 2 includes a control unit 21, a display unit 22, an operation unit 23, a card reader / writer 24, and the like. The control unit 21 controls the operation of the entire IC card processing device 2. The control unit 21 is composed of a processor (CPU) 25, a RAM 26, a ROM 27, a non-volatile memory 28, a communication unit 29, etc. For example, the control unit 21 is composed of a personal computer. The processor 25 executes various processes by executing a program stored in the ROM 27 or the non-volatile memory 28.

[0026] The RAM 26 functions as a working memory for temporarily holding data. The ROM 27 is a non-volatile memory that stores programs, control data, etc. The non-volatile memory 28 is a rewritable non-volatile memory. The communication unit 29 is an interface for communicating with an external device.

[0027] The control unit 21 has functions such as a function of sending commands to the IC card 1 by the card reader / writer 24, and a function of performing various processes based on the data received from the IC card 1. For example, the control unit 21 controls writing data to the non-volatile memory in the IC card 1 by sending a data write command to the IC card 1 via the card reader / writer 24. Also, the control unit 21 controls reading data from the IC card 1 by sending a read command to the IC card 1. Further, the control unit 21 controls the application selected in the IC card 1 by sending an application selection command to the IC card 1.

[0028] The display unit 22 is a display device that displays various information under the control of the control unit 21. The operation unit 23 is composed of a keyboard, a numeric keypad, a pointing device, etc. The operation unit 23 is for an operator of the IC card processing device 2 to input various operation instructions, data, etc. Also, the operation unit 23 functions as an input unit for inputting authentication information such as identification information or a password of the user of the IC card 1.

[0029] The card reader / writer 24 is a communication unit (second communication unit) for communicating with the IC card 1. The card reader / writer 24 is constituted by an interface corresponding to the communication method of the IC card 1. The card reader / writer 24 is constituted by an antenna and communication control for performing wireless communication with the IC card 1 which is a non-contact type IC card. The card reader / writer 24 supplies power supply power and an operation clock to the IC card 1. The card reader / writer 24 transmits a command to the IC card 1 and receives a response to the command from the IC card 1 based on the control by the control unit 21.

[0030] Next, the IC card 1 as a portable electronic device according to the embodiment will be described. A magnetic field is generated by the radio wave output from the antenna of the card reader / writer 24 between the interface 16 of the IC card 1 which is a non-contact type IC card and the card reader / writer 24 of the IC card processing apparatus 2. When the IC card 1 which is a non-contact type IC card communicates with the IC card processing apparatus 2 (card reader / writer 24), it has a function of measuring the intensity of the magnetic field generated in the interface 16 by the radio wave from the interface 16 and the card reader / writer 24.

[0031] The IC card 1 which is a non-contact type IC card becomes operable by being activated by the power supply power received by the interface 16 when the user brings it close to the card reader / writer 24 (antenna of the card reader / writer 24) of the IC card processing apparatus 2. In other words, the distance between the IC card 1 and the card reader / writer 24 is determined by the user's operation, and it is difficult to keep it at a constant distance in actual operation.

[0032] Generally, the magnetic field generated between the interface 16 of the IC card 1 and the card reader / writer 24 becomes stronger as the distance between the IC card 1 and the card reader / writer 24 decreases. Since the processor 11 of the IC card 1 can obtain a larger power supply power as the magnetic field strength increases, it is possible to operate the internal clock (operating clock) of the LSI as the IC chip Ca at a higher frequency.

[0033] As a specific example, there is an IC card 1 that can operate with an internal clock frequency ranging from 100 MHz to 10 MHz for a magnetic field strength of 7.5 A / m to 1.5 A / m. In this case, the processor 11 of the IC card 1 can set the internal clock frequency to 100 MHz if the magnetic field strength is 7.5 A / m or more, and can set a frequency ranging from 100 MHz to 10 MHz as the internal clock according to the magnetic field strength if the magnetic field strength is between 7.5 A / m and 1.5 A / m.

[0034] Since the processor 11 of the IC card 1 can perform more calculations (processing amount) per unit as the internal clock frequency increases, high-speed processing becomes possible. That is, since the IC card 1 can increase the internal clock frequency as the magnetic field strength increases, it can shorten the processing time (command processing time) for commands. The IC card 1 has a maximum value of the internal clock frequency (settable internal clock frequency) determined in advance according to the magnetic field strength as described above. Therefore, the processor 11 of the IC card 1 can set the internal clock frequency to the internal clock frequency corresponding to the magnetic field strength or a frequency lower than that.

[0035] On the other hand, as an operational rule, the IC card 1 may have an allowable time (allowable difference time) for the difference (processing time variation) between the fastest processing time and the slowest processing time in order to keep the variation of the processing time within an allowable range. The allowable difference time may be defined for each command, for each application program (hereinafter referred to as an application), or for a combination of commands and applications.

[0036] For example, when an allowable differential time is defined for each command, the IC card 1 sets a setting range for the frequency of the internal clock for each command so that even if the magnetic field strength fluctuates due to a change in the distance from the card reader / writer 24, the fluctuation (difference) in the processing time becomes the allowable differential time. As a result, the IC card 1 can keep the fluctuation (difference) in the processing time required for processing each command within the allowable range.

[0037] Also, when an allowable differential time is defined for each application, the IC card 1 sets a setting range for the frequency of the internal clock for each application so that the fluctuation (difference) in the processing time becomes the allowable differential time. As a result, the IC card 1 can keep the fluctuation in the processing time as an application within the allowable range.

[0038] FIG. 3 is a diagram showing an example of the allowable differential time for each command and the setting of the frequency of the internal clock (operation clock) corresponding to the allowable differential time. As shown in FIG. 3, an allowable differential time may be defined for a command or a combination of a command and a parameter to be processed by the IC card 1. Also, there is a command (MAX) for which no allowable differential time is defined. Further, there is a command for which it is defined that the differential time (allowable differential time) is minimized (MIN).

[0039] For example, for each command for which an allowable differential time is defined, the frequency of the internal clock (minimum frequency) that gives the latest processing time is set, and the frequency of the internal clock (maximum frequency) that gives the fastest processing time such that the difference from the latest processing time is the allowable differential time is set. The minimum frequency set for each command may be defined together with the allowable differential time, or may be the minimum frequency of the internal clock at which the IC card 1 can operate. Also, the maximum frequency for each command is set, for example, by calculating the fastest processing time from the latest processing time and the allowable differential time, and using it as the frequency of the internal clock that gives the fastest processing time.

[0040] As a specific example, in the example shown in FIG. 3, for the Select command, the allowable difference time is specified as 50 ms, and the frequency of the internal clock (minimum frequency) that represents the latest processing time is set to 20 MHz. In this case, for the Select command, the frequency of the internal clock (maximum frequency) that represents the fastest processing time calculated from the latest processing time and the allowable difference time is set to 40 MHz.

[0041] Also, in the example shown in FIG. 3, for the authentication command, the allowable difference time is specified as 100 ms, and the frequency of the internal clock (minimum frequency) that represents the latest processing time is set to 20 MHz. In this case, for the Select command, the frequency of the internal clock (maximum frequency) that represents the fastest processing time calculated from the latest processing time and the allowable difference time is set to 80 MHz. For the write command, the allowable difference time is specified as 50 ms, the frequency of the internal clock (minimum frequency) that represents the latest processing time is set to 20 MHz, and the frequency of the internal clock (maximum frequency) that represents the fastest processing time calculated from the latest processing time and the allowable difference time is set to 40 MHz.

[0042] Also, since the content of processing varies depending on parameters even for the same command, it is also possible to specify the allowable difference time for combinations of commands and parameters. As a specific example, in the example shown in FIG. 3, for the verification command with the parameter "Parameter A" (hereinafter referred to as verification command A), the allowable difference time is specified as 30 ms, and the frequency of the internal clock (minimum frequency) that represents the latest processing time is set to 10 MHz. For this verification command A, the frequency of the internal clock (maximum frequency) that represents the fastest processing time calculated from the latest processing time and the allowable difference time is set to 30 MHz.

[0043] In the example shown in FIG. 3, for the collation command (collation command B) where the parameter is "parameter B", the allowable difference time is defined as 50 ms, and the frequency of the internal clock (minimum frequency) that becomes the latest processing time is set to 20 MHz. For this collation command B, the frequency of the internal clock (maximum frequency) that becomes the fastest processing time calculated from the latest processing time and the allowable difference time is set to 40 MHz. As in the above-described collation command A and collation command B, even for the same command, different allowable difference times can be defined when the parameters are different, and the minimum frequency and the maximum frequency that result in different frequency ranges can be set.

[0044] FIG. 4 is a diagram showing a setting example (example of setting information) of the operation setting for the Select command defined as shown in FIG. 3. FIG. 4 shows the content of the operation setting to be set when the IC card 1 executes the Select command. In the setting example shown in FIG. 4, it is assumed that the IC card 1 can operate with the frequency of the internal clock ranging from 100 MHz to 10 MHz according to the magnetic field strength (7.5 A / m to 1.5 A / m).

[0045] According to the setting example shown in FIG. 4, when the IC card 1 executes the Select command, if the frequency of the internal clock according to the magnetic field strength is 40 MHz or more, the frequency of the internal clock is set to the maximum frequency of 40 MHz. Also, if the frequency of the internal clock according to the magnetic field strength is less than 40 MHz and 20 MHz or more (40 to 20 MHz), the frequency of the internal clock is set to the frequency of the internal clock according to the magnetic field strength (40 to 20 MHz). Further, if the clock frequency according to the magnetic field strength is less than 20 MHz, the frequency of the internal clock is set to the internal clock according to the magnetic field strength (19 to 10 MHz), and a status indicating an unprocessed state (such as a warning of insufficient internal clock frequency or processing delay) is set to be output in the response after the command processing.

[0046] FIG. 5 is a diagram showing a setting example of the operation setting for the collation command (collation command A) of parameter A with the parameters defined as shown in FIG. 3. When the IC card 1 executes the collation command A (when the collation command A is received), it performs operation settings such as the internal clock according to the settings shown in FIG. 5. In the setting example shown in FIG. 5, it is assumed that the IC card 1 can operate with the frequency of the internal clock ranging from 100 MHz to 10 MHz according to the magnetic field strength (7.5 A / m to 1.5 A / m).

[0047] According to the setting example shown in FIG. 5, when the IC card 1 executes the collation command A, if the frequency of the internal clock according to the magnetic field strength is 30 MHz or more, the frequency of the internal clock is set to the maximum frequency of 30 MHz. Also, if the frequency of the internal clock according to the magnetic field strength is less than 30 MHz and 10 MHz or more (30 to 10 MHz), the frequency of the internal clock is set to the frequency of the internal clock according to the magnetic field strength (30 to 10 MHz). Note that if the frequency of the internal clock according to the magnetic field strength is less than 10 MHz, the IC card 1 is assumed to be inoperable.

[0048] As described above, when executing the process for the command (or the combination of the command and the parameter) for which the allowable difference time is defined, the IC card 1 sets the frequency of the internal clock so that the processing time is within the allowable difference time regardless of how the magnetic field strength fluctuates. Also, when the latest processing time (the minimum frequency as the frequency of the internal clock for the latest processing time) is defined together with the allowable difference time, the IC card 1 sets the frequency of the internal clock corresponding to the fastest processing time such that the fluctuation of the processing time is within the allowable difference time regardless of how the magnetic field strength fluctuates, with the maximum frequency.

[0049] As a result, when the IC card 1 receives a command for which a tolerance difference time is defined, the IC card 1 sets the frequency of the internal clock within the range from the minimum frequency to the maximum frequency at which the variation (difference) in the processing time is within the tolerance difference time and executes command processing. As a result, even if the processing time varies due to a variation in the magnetic field strength caused by a variation in the distance from the card reader / writer 24 or the like, the IC card 1 can execute command processing at the frequency of the internal clock set so that the variation in the processing time is within the tolerance difference time set for each command.

[0050] Next, a command for which a tolerance difference time is not defined among the commands to be processed by the IC card 1 will be described. Among the commands to be processed by the IC card 1 according to the embodiment, there are also commands for which a tolerance difference time is not defined, such as the read command illustrated in FIG. 3. In the setting information of each command for which a tolerance difference time is not defined, the minimum frequency and the maximum frequency are not defined, and the frequency of the internal clock is set to the frequency of the internal clock corresponding to the magnetic field strength (the maximum value of the settable internal clock).

[0051] As a specific example, in the example shown in FIG. 3, for the read command, a tolerance difference time is not defined, and the frequency of the internal clock is set to MAX (frequency corresponding to the magnetic field strength). When the IC card 1 executes processing for a command for which a tolerance difference time is not defined, the IC card 1 operates by setting the frequency of the internal clock to the frequency of the internal clock corresponding to the magnetic field strength (the maximum value of the settable frequencies).

[0052] FIG. 6 is a diagram showing a setting example of operation settings for the read command defined as shown in FIG. 3. According to the setting shown in FIG. 6, when the IC card 1 executes a read command (when it receives a read command), it sets the frequency of the internal clock to the frequency of the internal clock corresponding to the measured magnetic field strength. Here, it is assumed that the IC card 1 can operate with the frequency of the internal clock corresponding to the magnetic field strength (7.5 A / m to 1.5 A / m) ranging from 100 MHz to 10 MHz. In this case, if the frequency of the internal clock corresponding to the measured magnetic field strength is 100 MHz or less and 10 MHz or more, the IC card 1 sets the frequency of the internal clock to the frequency of the internal clock corresponding to the magnetic field strength (100 to 10 MHz).

[0053] Like the above-described read command, the IC card 1 executes the processing for a command whose allowable difference time is not defined at the frequency of the internal clock corresponding to the magnetic field strength. Thereby, even if the processing time may vary due to the variation of the magnetic field strength accompanying the variation of the distance between the IC card and the card reader / writer, the IC card 1 can perform the processing of the command whose allowable difference time is not defined at the fastest processing time corresponding to the actual situation (magnetic field strength).

[0054] Next, a command for which the IC card 1 sets the difference time to be minimum (a command for setting the frequency of the internal clock to a fixed predetermined frequency) among the commands to be processed by the IC card 1 will be described. Among the commands to be processed by the IC card 1 according to the embodiment, there may be included a command for which the difference time (allowable difference time) is defined to be minimum, such as the random number generation command illustrated in FIG. 3. The command for which the difference time is minimum is processed with the frequency of the internal clock set to a predetermined frequency regardless of the frequency of the internal clock corresponding to the magnetic field strength.

[0055] As a specific example, in the example shown in FIG. 3, the command processing for the random number generation command is defined to minimize the allowable difference time (difference time), and the frequency of the internal clock is set to a prescribed fixed value (predetermined frequency). When the IC card 1 executes processing for a command for which the difference time is minimized (or the frequency of the internal clock is the predetermined frequency), the internal clock is set to the predetermined frequency regardless of the frequency of the internal clock according to the magnetic field strength.

[0056] FIG. 7 is a diagram showing a setting example of the operation setting for the random number generation command defined as shown in FIG. 3. According to the setting shown in FIG. 7, when the IC card 1 executes a random number generation command (when receiving a random number generation command), the frequency of the internal clock is set to 10 MHz, which is the predetermined frequency corresponding to the random number generation command, and it operates. Here, even if the IC card 1 can operate with the frequency of the internal clock being 100 MHz to 10 MHz according to the magnetic field strength (7.5 A / m to 1.5 A / m), the frequency of the internal clock is set to the predetermined frequency of 10 MHz regardless of the frequency of the internal clock according to the magnetic field strength.

[0057] Like the random number generation command described above, the IC card 1 executes processing for a command that minimizes the allowable difference time with the internal clock at the predetermined frequency. Thereby, even if the magnetic field strength fluctuates due to the fluctuation in the distance between the IC card 1 and the card reader / writer 24, the IC card 1 can set a command for minimizing the processing time variation. As a result, for commands that require the processing time not to fluctuate due to reasons such as stability and safety, the IC card 1 can ensure that the processing time of the command processing does not fluctuate even if there is a fluctuation in the magnetic field strength due to the operating state (such as the distance from the card reader / writer 24).

[0058] Next, an operation example in which the IC card 1 as a portable electronic device according to the embodiment sets an internal clock according to the magnetic field strength for each command will be described. FIG. 8 is a flowchart for explaining an operation example in which an IC card 1 as a portable electronic device according to an embodiment sets an internal clock according to a magnetic field strength for each command. The IC card processing device 2 outputs a radio wave for activating the IC card by the card reader / writer 24 and periodically transmits an initial response request command (REQA or REQB). The initial response request command transmitted to the IC card 1 is, for example, REQA (REQuest command typeA) or REQB (REQuest command typeB) defined in ISO / IEC 14443.

[0059] The IC card 1 receives the radio wave from the card reader / writer 24 of the IC card processing device 2 through the interface 16. The IC card 1 is activated by generating a DC voltage for power supply generated from the received radio wave. When the IC card 1 is activated, the processor 11 receives an initial response request command from the IC card processing device 2 (ST11).

[0060] The processor 11 of the IC card 1 transmits an initial response (ATQA or ATQB) as a response to the received initial response request command to the IC card processing device 2 (ST12). The initial response output by the IC card 1 is, for example, ATQB (Answer To REQuest command typeB) or ATQA (Answer To REQuest command typeA) defined in ISO / IEC 14443.

[0061] After transmitting the initial response, the processor 11 of the IC card 1 performs a communication startup process for executing communication with the IC card processing device 2 (ST13). When the communication setting between the IC card 1 and the IC card processing device 2 is completed, the processor 11 of the IC card 1 can execute processing for commands from the IC card processing device 2 and waits for command reception (ST14).

[0062] IC card 1 receives a command output from the card reader / writer 24 of the IC card processing device 2 via the interface 16. When the processor 11 of the IC card 1 receives the command (ST14, YES), it measures the intensity of the magnetic field generated between the interface 16 and the card reader / writer 24 (step ST15).

[0063] When the processor 11 of the IC card 1 obtains the actually measured magnetic field intensity, it specifies the frequency of the internal clock (the maximum value of the frequencies that can be set for the internal clock) according to the obtained magnetic field intensity (ST16). For example, the processor 11 specifies the frequency of the internal clock according to the actually measured magnetic field intensity based on information such as information specifying in advance the frequency of the internal clock according to the magnetic field intensity. As a specific example, the frequency of the internal clock according to the magnetic field intensity is specified such that the frequency of the internal clock is 100 MHz when the magnetic field intensity is 7.5 A / m or more, 10 MHz when the magnetic field intensity is 1.5 A / m, and between 100 MHz and 10 MHz when the magnetic field intensity is between 7.5 A / m and 1.5 A / m.

[0064] Note that the measurement of the magnetic field intensity and the specification of the frequency of the internal clock according to the magnetic field intensity are not limited to being performed when a command is received, and may be performed at any timing. For example, the processor 11 may specify the frequency of the internal clock according to the magnetic field intensity when a command is received based on the measurement result of the magnetic field intensity measured at a predetermined period or the like.

[0065] When the processor 11 specifies the frequency of the internal clock according to the actually measured magnetic field intensity, it performs an operation setting including setting the frequency of the internal clock based on the setting information corresponding to the received command and the frequency of the internal clock according to the magnetic field intensity (ST17). For example, the processor 11 performs an operation setting based on the setting information for each command (or a combination of a command and parameters) as exemplified in FIGS. 4 to 7.

[0066] For example, when the processor 11 receives a command with a specified tolerance time difference, such as the Select command for the setting information illustrated in FIG. 4 or the verification command A for the setting information illustrated in FIG. 5, it sets the internal clock based on the setting information corresponding to the received command so that the internal clock is within the range from the slowest internal clock to the fastest internal clock. Further, according to the setting information illustrated in FIG. 4, if the frequency of the internal clock corresponding to the magnetic field strength is less than the minimum frequency, the processor 11 not only sets the internal clock to the frequency corresponding to the magnetic field strength but also sets the content of the status added to the response.

[0067] In addition, when the processor 11 receives a command without a specified tolerance time difference, such as the read command illustrated in FIG. 6, it sets the frequency of the internal clock to the frequency corresponding to the magnetic field strength. In addition, when the processor 11 receives a command with a minimum tolerance time difference, such as the random number generation command illustrated in FIG. 7, it sets the frequency of the internal clock to the predetermined frequency specified by the setting information.

[0068] When the processor 11 performs an operation setting based on the setting information corresponding to the received command, it operates at the set frequency of the internal clock and executes processing for the received command (ST18). The processor 11 creates response data indicating the command processing result as a result of the processing for the received command and transmits the created response data to the IC card processing device 2 (ST19). Here, when it is set to output a specific status in the operation setting, the processor 11 outputs response data including the status. For example, in the example shown in FIG. 4, if the frequency of the internal clock corresponding to the magnetic field strength is less than the minimum frequency, the processor 11 transmits response data with a status of unprocessed to the IC card processing device 2.

[0069] As described above, the IC card 1 as a portable electronic device according to the embodiment has a storage unit that stores setting information defined for each command so that the variation in the command processing time is within the allowable difference time. The IC card operates with an internal clock of a frequency set based on the setting information for each received command stored in the storage unit, and executes command processing.

[0070] Thereby, even in an operation mode where the distance between the IC card according to the embodiment and the card reader / writer is assumed to vary, the frequency of the internal clock can be set so that the variation in the processing time is within the allowable difference time defined for each command. As a result, even if there are variations in the usage method for each user, processing can be executed with a processing time within the allowable range required for command processing, and users can be encouraged to use the IC card in a manner that presents it to the card reader / writer within the allowable range.

[0071] Next, an operation example in which the IC card 1 as a portable electronic device according to the embodiment sets an internal clock according to the magnetic field strength for each application will be described. One IC card 1 as a portable electronic device may have a plurality of applications for each use installed for use in a plurality of applications. The IC card 1 can perform processing for a specific use by executing an application selected from a plurality of applications by the IC card processing device 2. For this reason, the IC card 1 may set the frequency of the internal clock based on the setting information for each application. Hereinafter, an operation example in which the IC card 1 sets the frequency of the internal clock for each application will be described.

[0072] FIG. 9 is a flowchart for explaining an operation example in which the IC card 1 as a portable electronic device according to the embodiment sets the frequency of the internal clock according to the setting information for each application. The IC card processing device 2 outputs radio waves for activating the IC card by the card reader / writer 24, and periodically transmits an initial response request command (REQA or REQB). The initial response request command transmitted to the IC card 1 is, for example, REQA (REQuest command typeA) or REQB (REQuest command typeB) defined in ISO / IEC 14443.

[0073] The IC card 1 receives radio waves from the card reader / writer 24 of the IC card processing device 2 through the interface 16. The IC card 1 is activated by generating a DC voltage for power supply from the received radio waves. When the IC card 1 is activated, the processor 11 receives an initial response request command from the IC card processing device 2 (ST31).

[0074] The processor 11 of the IC card 1 transmits an initial response (ATQA or ATQB) as a response to the received initial response request command to the IC card processing device 2 (ST32). The initial response output by the IC card 1 is, for example, ATQB (Answer To REQuest command typeB) or ATQA (Answer To REQuest command typeA) defined in ISO / IEC 14443.

[0075] After transmitting the initial response, the processor 11 of the IC card 1 performs communication startup processing for executing communication with the IC card processing device 2 (ST33). When the communication setting between the IC card 1 and the IC card processing device 2 is completed, the processor 11 of the IC card 1 can execute processing for commands from the IC card processing device 2 and waits for command reception (ST34).

[0076] When the processor 11 of the IC card 1 receives a command via the interface 16 (ST34, YES), it determines whether the received command is a command that requests selection of an application (ST35). If the received command is not a command that requests selection of an application (ST35, NO), the processor 11 of the IC card 1 proceeds to ST39 and executes command processing.

[0077] When the received command is a command that requests selection of an application (ST35, YES), the processor 11 of the IC card 1 measures the magnetic field strength generated between the interface 16 and the card reader / writer 24 (ST36).

[0078] When the processor 11 of the IC card 1 acquires the actually measured magnetic field strength, it specifies the frequency of the internal clock (the maximum value of the settable internal clock frequency) according to the acquired magnetic field strength (ST37). For example, the processor 11 specifies the frequency of the internal clock according to the measured magnetic field strength based on the information indicating the frequency of the internal clock according to the pre-specified magnetic field strength. Note that the measurement of the magnetic field strength and the specification of the operable internal clock according to the magnetic field strength may be performed at any timing.

[0079] When the processor 11 specifies the frequency of the internal clock according to the magnetic field strength, it sets the frequency of the internal clock based on the setting information corresponding to the selected application (ST38). For example, the IC card 1 stores the setting information indicating the setting content of the internal clock frequency for each application in the NVM 14. The processor 11 sets the frequency of the internal clock based on the setting information for each application stored in the NVM 14.

[0080] As the setting content of the frequency of the internal clock in the setting information for each application, it may be to define the frequency of the internal clock within the range from the minimum frequency to the maximum frequency. When the minimum frequency and the maximum frequency are defined in the setting information of the selected application, the processor 11 sets the frequency of the internal clock to be a frequency corresponding to the magnetic field strength within the range from the minimum frequency to the maximum frequency.

[0081] Also, as the setting content of the frequency of the internal clock in the setting information for each application, it may be to define setting the frequency of the internal clock to the frequency (MAX) corresponding to the magnetic field strength. In this case, the processor 11 sets the frequency of the internal clock to be the frequency (MAX) corresponding to the magnetic field strength. Also, as the setting content of the frequency of the internal clock in the setting information for each application, it may be to define setting the frequency of the internal clock to a predetermined frequency. In this case, the processor 11 sets the frequency of the internal clock to be the predetermined frequency.

[0082] After setting the frequency of the internal clock based on the setting information corresponding to the selected application, the processor 11 operates at the set frequency of the internal clock and executes processing for the received command (ST39). The processor 11 creates response data indicating the result of the command processing as the result of the processing for the received command, and transmits the created response data to the IC card processing device 2 (ST40).

[0083] As described above, the IC card 1 as a portable electronic device according to the embodiment has a storage unit that stores setting information regarding the frequency setting of the internal clock defined for each application. The IC card sets the frequency of the internal clock corresponding to the selected application based on the setting information for each application stored in the storage unit.

[0084] As a result, the IC card according to the embodiment can set the frequency of the internal clock so that even if the distance from the card reader / writer varies, the variation in processing time is within the allowable range required by the application. As a result, even if there are variations in the usage method for each user, processing can be performed with a processing time within the allowable range required by the application, and users can be encouraged to present the IC card to the card reader / writer within the allowable range.

[0085] Moreover, the functions described in each of the above-described embodiments are not limited to being configured using hardware, and can also be realized by causing a computer to read a program describing each function using software. Also, each function may be configured by appropriately selecting either software or hardware.

[0086] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Description of Reference Numerals

[0087] 1…IC card (portable electronic device), C…main body, Ca…IC chip, M…module, 2…IC card processing device (external device), 11…processor, 12…RAM, 13…ROM, 14…NVM (memory), 15…communication control unit, 16…interface, 21…control unit, 22…display unit, 23…operation unit, 24…card reader / writer.

Claims

1. An interface that communicates with an IC card processing device in a contactless manner, A memory that stores setting information that defines the setting content of the frequency of the operation clock, A processor that sets the frequency of the operation clock based on the frequency of the operation clock corresponding to the intensity of the magnetic field generated in the interface and the setting information stored in the memory, and executes processing for a command received from the IC card processing device by the interface, A portable electronic device having the above.

2. The memory stores setting information that defines the setting content of the frequency of the operation clock for each command, The processor sets the frequency of the operation clock for executing the processing for the command based on the frequency of the operation clock corresponding to the intensity of the magnetic field and the setting information for the command received from the IC card processing device, The portable electronic device according to claim 1.

3. The memory stores setting information that defines the maximum frequency and the minimum frequency that can be set as the operation clock for each command, When the processor executes a command for which the maximum frequency and the minimum frequency are defined, if the frequency of the operation clock corresponding to the intensity of the magnetic field is greater than or equal to the maximum frequency, the processor sets the frequency of the operation clock to the maximum frequency, and if the frequency of the operation clock corresponding to the intensity of the magnetic field is less than the maximum frequency and greater than or equal to the minimum frequency, the processor sets the frequency of the operation clock to the frequency of the operation clock corresponding to the intensity of the magnetic field, The portable electronic device according to claim 2.

4. The command for which the maximum frequency and the minimum frequency are defined is a command for which a tolerance difference time, which is an allowable range for fluctuations in the processing time of the command, is defined, The minimum frequency is the frequency of the operation clock at which the processing of the command takes the slowest processing time, and the maximum frequency is the frequency of the operation clock at which the fastest processing time is set from the slowest processing time and the tolerance difference time, The portable electronic device according to claim 3.

5. The memory further stores setting information indicating a command for which the frequency of the operation clock is the maximum value that can be operated, When the processor executes a command for which the frequency of the operation clock is the maximum value that can be operated, the processor sets the frequency of the operation clock to the frequency of the operation clock corresponding to the intensity of the magnetic field, The portable electronic device according to claim 3.

6. The memory further stores setting information indicating a command for setting the frequency of the operation clock to a predetermined frequency. When the processor executes a command for setting the frequency of the operation clock to a predetermined frequency, the processor sets the frequency of the operation clock to the predetermined frequency. The portable electronic device according to claim 5.

7. The memory stores information indicating the setting content of the frequency of the operation clock for each application. The processor sets the frequency of the operation clock based on the frequency of the operation clock corresponding to the intensity of the magnetic field and the setting information for the application selected from the IC card processing device. The portable electronic device according to claim 1.

8. A module including: an interface that communicates with the IC card processing device in a non-contact manner; a memory that stores setting information defining the setting content of the frequency of the operation clock; and a processor that sets the frequency of the operation clock based on the frequency of the operation clock corresponding to the intensity of the magnetic field generated in the interface and the setting information stored in the memory, and executes processing for a command received from the IC card processing device by the interface. A main body having the module. An IC card including the above.

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