JP2012194904A - Portable electronic device, ic card, and communication method applied to portable electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable electronic device and a communication method applied to the portable electronic device which can efficiently perform communication.SOLUTION: A portable electronic device comprises: communication means; setting means; response means; and adjustment means. The communication means transmits/receives data composed of pieces of data in frame units. The setting means sets the maximum frame number which can be received and an initial value of the response start time for starting to respond to received data. At the moment when the response start time for data received by the communication means has passed, the response means transmits reception confirmation of the data. The adjustment means adjusts the response start time according to a latency time from when data is completely received by the communication means until the response start time for the data.

Description

  Embodiments described herein relate generally to a portable electronic device such as an IC card and a communication method used for the portable electronic device.

  A portable electronic device such as an IC card performs various processes by performing data communication with a terminal device. Some communication methods between portable electronic devices and terminal devices transmit and receive data divided into frame units. In a communication method for transmitting and receiving data in frame units, the maximum number of frames that can be transmitted and received at a time is set first, and data is transmitted and received in frames within the maximum number of frames. However, when the maximum number of frames that can be transmitted and received at a time is fixed, efficient communication according to the size of data that is actually transmitted and received may be difficult.

ETSI TS102613

  An object of one embodiment of the present invention is to provide a portable electronic device, an IC card, and a communication method used for the portable electronic device that can efficiently communicate.

  According to this embodiment, the portable electronic device includes communication means, setting means, response means, and adjustment means. The communication means transmits and receives data composed of data in frame units. The setting means sets the maximum number of frames that can be received and an initial value of a response start time for starting a response to the received data. The response means transmits a reception confirmation of the data when the response start time for the data received by the communication means has elapsed. The adjustment unit corrects the response start time according to the waiting time from the completion of data reception by the communication unit to the response start time for the data.

FIG. 1 is a block diagram illustrating a configuration example of an IC card and an IC card system. FIG. 2 is a block diagram illustrating a configuration example of a mobile phone as an example of a terminal device. FIG. 3 is a diagram illustrating an example of a frame transmitted and received between the IC card and the terminal device in the fixed timeout time mode. FIG. 4 is a diagram illustrating an example of a frame transmitted and received between the IC card and the terminal device in the timeout time adjustment mode. FIG. 5 is a sequence diagram illustrating an example of a communication procedure between the IC card and the terminal device in the adjustment mode. FIG. 6 is a flowchart for explaining the flow of communication processing in the IC card.

Hereinafter, embodiments will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a configuration example of an IC card system having an IC card 1 as a portable electronic device and a terminal device 2.
The IC card system shown in FIG. 1 is a communication system in which an IC card 1 and a terminal device 2 transmit and receive data bidirectionally. For example, the IC card system is assumed to have an operation mode in which the IC card 1 is mounted on a mobile phone as the terminal device 2. In such an operation mode, the IC card 1 and the terminal device 2 perform data communication in a state where the IC card 1 is attached to the terminal device 2. The communication method between the IC card 1 and the terminal device 2 is full duplex communication such as SWP communication.

  The IC card 1 operates by supplying power from the terminal device 2. For example, the IC card 1 is a contact-type portable electronic device (contact IC card) that communicates with the terminal device 2 in physical and electrical contact. However, the IC card 1 may be a non-contact portable electronic device (non-contact IC card) that performs wireless communication in a non-contact state with the terminal device 2 using an antenna or a wireless communication unit. Furthermore, the IC card 1 may be a composite IC card (dual interface IC card) having a communication function as a non-contact IC card and a communication function as a contact IC card.

As shown in FIG. 1, the IC card 1 includes a control unit (CPU) 11, a program memory 12, a working memory 13, a data memory 14, a communication control unit 15, a power supply unit 16, an interface 17, and the like.
The IC card 1 is composed of a card-shaped main body C. One (or a plurality) of IC chips 1 a and an interface 17 are embedded in the card-like main body C forming the IC card 1. The IC chip 1a includes a control unit (CPU) 11, a program memory 12, a working memory 13, a data memory 14, a communication control unit 15, a power supply unit 16, and the like. The IC chip 1a is modularized while being connected to the interface 17, and is embedded in a card-like main body C that forms the IC card 1.

  The control unit 11 controls the entire IC card 1. The control unit 11 includes a processor such as a CPU. The control unit 11 operates based on a control program and control data stored in the program memory 12 or the data memory 14. For example, the control unit 11 executes a process according to a command given from the terminal device 2 by executing a control program that controls the operation stored in the program memory 12. The control unit 11 includes a timer 11a that measures time. For example, the timer 11a measures the transmission timing of response data.

  The program memory 12 is constituted by a read-only memory (ROM: read-only memory). The program memory 12 stores a control program, control data, and the like that control operations according to the specifications of the IC card 1.

  The working memory 13 is composed of a volatile memory (RAM; random access memory). The working memory 13 functions as a buffer memory for temporarily storing data. For example, the working memory 13 can be used as a communication buffer that temporarily stores data to be transmitted and received in communication processing with the terminal device 2. The working memory 13 is also used as a memory for temporarily holding various write data.

  The data memory (nonvolatile memory) 14 is a nonvolatile memory capable of writing data. The data memory 14 is composed of, for example, an EEPROM or a flash memory. In the data memory 14, various information (application program, operation data, etc.) according to the purpose of use of the IC card 1 is written. When the IC card 1 is used for a plurality of usage purposes, the data memory 14 stores a plurality of applications corresponding to the usage purposes.

  The communication control unit 15 controls data communication with the terminal device 2 via the interface 17. When the IC card 1 is a contact IC card, the communication control unit 15 transmits and receives data via the interface 17 as a contact unit that physically and electrically contacts the terminal device 2. In the case of a non-contact type IC card, the communication control unit 15 modulates or demodulates data to be transmitted / received by an antenna as the interface 17.

  The power supply unit 16 supplies power and clock pulses for operating each unit of the IC card 1. For example, when the IC card 1 is a contact type IC card, the power supply unit 16 supplies power and clock pulses directly supplied from an external device via the interface 17 to each unit. When the IC card is a non-contact type IC card, the power supply unit 16 generates power and clock pulses from the radio wave received by the antenna as the interface 17 and supplies the power and clock pulses to each unit in the IC card. .

  The working memory 13 stores setting data such as communication settings set in the communication establishment process. For example, the working memory 13 stores a set value of a maximum number of continuous transmission frames (hereinafter also referred to as a maximum frame number (Sliding Window size)). In addition, the working memory 13 stores a set value and an initial value of a time (timeout time) from when a frame is received until reception confirmation is transmitted. The working memory 13 stores the initial value of the timeout time set in the communication establishment process until the communication process ends. However, the set value of the timeout time stored in the working memory 13 indicates the currently set timeout time and is updated as appropriate.

Next, the configuration of the terminal device 2 will be described.
The terminal device 2 supplies power for operating the IC card 1 and performs data communication with the IC card 1. Here, it is assumed that the terminal device 2 is a mobile phone. The mobile phone as the terminal device 2 is assumed to have an operation mode in which communication as a mobile phone can be used with the IC card 1 possessed by each user attached. The IC card 1 is mounted in an IC card socket provided in a mobile phone as the terminal device 2. In a state where the IC card socket of the mobile phone is mounted, the contact portion as an interface of the mobile phone and the interface of the IC card 1 come into contact with each other, thereby enabling data communication. The cellular phone 2 supplies power and clock pulses for operation to the IC card 1 through a contact portion that is in physical contact with the IC card 1.

FIG. 2 is a block diagram illustrating a configuration example of a mobile phone as an example of the terminal device 2.
In the configuration example shown in FIG. 2, the mobile phone 2 includes a control unit 31, a RAM 32, a ROM 33, a nonvolatile memory 34, an IC card interface (first interface) 35, a memory card interface (second interface) 36, An antenna 37, a communication unit 38, an audio unit 39, a vibration unit 40, a display unit 41, an operation unit 42, a power supply unit 43, and the like are included.

  The control unit 31 controls the entire mobile phone 2. The control unit 31 includes a CPU, an internal memory, various interfaces, and the like. The control unit 31 has, as its basic functions, a display control function for controlling the display of the display unit 41, a PLL (Phase Locked Loop) circuit, a data stream path switching, a DMA (Direct Memory Access) controller, an interrupt controller, It has functions such as timer, UART (Universal Asynchronous Receiver Transmitter), secrecy, HDLC (High-level Data Link Control procedure) framing, device controller, and the like.

  The RAM 32 is a volatile memory for storing work data. The RAM 32 stores setting data set in the communication establishment process as communication setting information with the IC card 1. For example, the RAM 32 stores a set value of a maximum number of continuous transmission frames (hereinafter also referred to as a maximum number of frames (Sliding Window size)). Further, the RAM 32 stores a set value and an initial value of a time (timeout time) from when a frame is received until reception confirmation is transmitted. The RAM 32 stores the initial value of the timeout time set in the communication establishment process until the communication process ends. However, the set value of the timeout time stored in the RAM 32 indicates the currently set timeout time and is updated as appropriate.

  The ROM 33 is a non-volatile memory that stores control programs, control data, and the like. The ROM 33 is a nonvolatile memory. For example, the ROM 33 stores a control program and control data for performing basic control of the mobile phone 2 in advance. The control unit 31 realizes basic control of the mobile phone 2 by executing a control program stored in the ROM 33.

  The nonvolatile memory 34 is a rewritable nonvolatile memory that stores various data. The nonvolatile memory 34 stores various application programs (applications), control data, user data, and the like. The control unit 31 implements various functions by executing application programs stored in the nonvolatile memory 34.

  The first interface 35 is an interface to which the IC card 1 is attached. The first interface 35 is connected to the control unit 31. Thus, the control unit 31 can perform data communication with the IC card 1 via the first interface 35. The second interface 36 is an interface to which the memory card M can be attached and detached. The second interface 36 is connected to the control unit 31. The control unit 31 can access (write or read data) the memory card M attached to the second interface 36.

  The communication unit 38 transmits and receives telephone call data or data communication data via radio waves via the communication antenna 37. The audio unit 39 has an analog front end unit and an audio unit, and inputs and outputs audio. The vibration unit 40 is configured by a vibration mechanism that vibrates the entire mobile phone 2. The display unit 41 is controlled by the control unit 31 to turn on / off the display and display contents. The operation unit 42 is configured by a keyboard or the like, and an operation instruction from the user is input. The power supply unit 43 is configured by a battery or the like, and supplies power to each unit in the mobile phone 2. The power supply unit 43 also has a function of supplying power to the IC card 1 connected via the first interface 35 and the memory card M connected via the second interface 36.

Next, communication between the IC card 1 and the terminal device 2 will be described.
In the IC card system of the present embodiment, the IC card 1 and the terminal device 2 perform full duplex communication such as SWP communication. In this system, the format of data to be transmitted is determined in advance. The IC card 1 and the terminal device 2 transmit data in units of frames. The amount of transmission data per frame is a prescribed size, and data to be transmitted / received is transmitted / received divided into frame units.

  First, the terminal device 2 and the IC card 1 set initial values for communication settings by communication establishment processing. In the communication establishment process, the terminal device 2 transmits a reset request to the IC card 1, and the IC card 1 returns setting data to the terminal device 2. In the reset request, the terminal device 2 sends a maximum number of frames that can be continuously transmitted to the IC card 1 (hereinafter referred to as “Sliding Window size (WS)”), and a response timeout time as a response to the reception confirmation. Set (Acknowledge time) etc. with parameters. The initial value of the timeout time is set to a length corresponding to the WS value.

  As the value of the sliding window size (WS value), for example, any one of “2”, “3”, and “4” is set. It is assumed that the initial value of the timeout time is a time determined according to the WS value. The initial value of the timeout time is set to a shorter time as the WS value becomes smaller. The timeout time is set to a value according to the communication speed between the terminal device 2 and the IC card 1 and the size of each frame. For example, the initial value of the timeout time when the WS value is “4” is about 5 ms. In this case, when the WS value is “3” with reference to the initial value “5 ms” of the timeout time when the WS value is “4”, the initial value of the timeout time is about 4.5 to 3.0 ms ( For example, if the WS value is “2”, the initial value of the timeout time may be about 3.5 to 2.0 ms (for example, 2.5 ms).

  As described above, the initial value of the timeout time is determined according to the WS value, and the larger the WS value, the larger the value. Therefore, when the timeout time is fixed to the initial value, the timing for outputting a response such as reception confirmation is set according to the WS value even when the actual number of frames to be transmitted is smaller than the set WS value. Time. As a result, when the number of frames to be actually transmitted is smaller than the set WS value, an extra waiting time occurs.

  In the IC card system of the present embodiment, the IC card selects a fixed mode for fixing the timeout time to an initial value or an adjustment mode for automatic adjustment in the communication establishment process (that is, at the time of reset). For example, FIG. 3 is a diagram illustrating a communication example in a fixed mode in which the timeout time is fixed to an initial value.

First, an example of processing in a fixed mode in which the timeout time is fixed to an initial value will be described.
In the example shown in FIG. 3, it is assumed that WS (Sliding Window size) = 4. As shown in FIG. 3, the sliding window size is set in the communication establishment process between the terminal device 2 and the IC card 1. The terminal device 2 transmits to the IC card 1 a frame (U-Frame) requesting reset (RSET) with WS = 4. The IC card 1 sets the WS value to 4, and returns a frame (U-Frame) indicating completion of the initial setting to the terminal device 2. In the subsequent communication, the terminal device 2 performs frame exchange with the IC card 1 with the WS value set to “4”.

The initial value of the timeout time (Acknowledge time) is calculated by, for example, the following formula for WS (Sliding Window Size).
Timeout time = (default fixed value) × WS / (maximum value that can be set in WS)
Here, it is assumed that the WS value is set to any one of 2, 3, and 4, and the maximum value that can be set as the WS value is “4”. If the default fixed value is 5 ms, the timeout time (Acknowledge time) is calculated by the following equation.
Timeout time (Acknowledge time) = 5 ms x WS / 4
According to the above formula, when the WS value is “4”, the initial value of the timeout time is 5 ms × 4/4 = 5 ms, and when the WS value is “3”, the initial value of the timeout time is 5 ms × When 3/4 = 3.75 ms and the WS value is “2”, the initial value of the timeout time is 5 ms × 2/4 = 2.5 ms.

  When the communication establishment process including the setting of the initial value of the timeout time as described above is completed, the terminal device 2 and the IC card 1 start frame exchange. The terminal device 2 transmits a transmission message to the IC card 1 as data for each of a plurality of frames whose maximum value is the set WS value. For example, when transmitting large data that does not fit in the maximum number of frames, the terminal device 2 divides the transmission data into data composed of a plurality of frames having a WS value as a maximum value and transmits the data to the IC card 1.

  That is, when WS = 4 is set when the timeout time is fixed mode, the timeout time corresponding to the transmission message transmitted in 4 frames is set as a fixed value regardless of the number of frames in the transmission message (I-Frame). Is set. For this reason, it is possible to respond to a transmission message (I-Frame) sent in 4 frames with a corresponding timeout time. However, if the number of frames of the transmission message (I-Frame) is 3 frames or less than the maximum value (“4”), the reception of the transmission message is completed, and then the number of frames exceeds the maximum value (“4”). A waiting time corresponding to a small number of frames occurs.

  For example, in the example shown in FIG. 3, when a transmission message (I-Frame) consisting of 4 frames is received from the terminal device 2, the IC card 1 is set according to the WS value from the end of the received first frame. A notification of reception confirmation is sent when the timeout time elapses. Further, when a transmission message (I-Frame) consisting of 3 frames is received from the terminal device 2, the IC card 1 receives data for 3 frames, and then data for 1 (4-3 = 1) frames is received. Wait for a receivable waiting time before sending a reception confirmation notification. When receiving a transmission message (I-Frame) consisting of two frames from the terminal device 2, the IC card 1 receives data for two frames, and then receives data for two (4-2 = 2) frames. Wait for a receivable waiting time before sending a reception confirmation notification.

  As described above, in the fixed mode in which the timeout time is fixed to the initial value, when the transmission message having the number of frames smaller than the set WS value is received, the IC card 1 is from the completion of reception until the response is transmitted. Waiting time occurs. The smaller the number of frames with respect to the WS value, the longer the waiting time of the IC card 1 from the completion of reception to the response transmission.

Next, communication in an adjustment mode that automatically adjusts the timeout time will be described.
FIG. 4 is a diagram illustrating an example of frames transmitted and received in the adjustment mode in which the timeout time is automatically adjusted. FIG. 5 is a diagram illustrating an example of a communication sequence between the terminal device 2 and the IC cart 1 when the timeout time is in the adjustment mode.
In the communication establishment process, the IC card 1 sets WS. In the example shown in FIGS. 4 and 5, WS = 4. In the communication establishment process, the IC card 1 is set with an initial value AT0 of a timeout time (Acknowledge time) corresponding to the set WS value. The initial value AT0 of the timeout time corresponding to the WS value is calculated by the above-described formula, for example.

  In the communication establishment process, the terminal device 2 may specify whether the timeout time (Acknowledge time) is set to the fixed mode or the adjustment mode together with the reset request to the IC card 1. For example, the terminal device 2 gives a parameter for specifying whether the timeout time is set to the fixed mode or the adjustment mode in the UA frame including the reset request transmitted to the IC card 1 in the communication establishment process. The IC card 1 selects whether to set the timeout time to the fixed mode or the adjustment mode according to the parameters of the UA frame including the reset request.

  In the adjustment mode in which the timeout time is automatically adjusted, the IC card 1 is currently set according to the time from when the transmission message (I-Frame) is actually received from the terminal device 2 until the timeout time elapses. It is determined whether or not to adjust (correct) the timeout time. For example, when the elapsed time T from the completion of reception of the transmission message to the timeout time is not less than the first reference value A and not more than the second reference value A + α, the IC card 1 does not change the timeout time and changes the current time Maintain the timeout value setting.

  Further, when the elapsed time T from the completion of reception of the transmission message to the timeout time is less than the first reference value A, the IC card 1 corrects the set value of the timeout time to the initial value of the timeout time according to the WS value. Make adjustments. When the elapsed time T from the completion of reception of the transmission message to the timeout time is longer than the second reference value A + α, the IC card 1 performs adjustment to shorten the set value of the timeout time. For example, the IC card 1 adjusts the timeout time to a short time by multiplying the current timeout time by B (0 <B <1). The value of B is assumed to be about 0.5 to 0.75, for example. However, the method of adjusting the timeout time to a short value is not limited to the method of multiplying by B. For example, the timeout time may be adjusted to a value obtained by subtracting a predetermined time from the current set value.

  That is, when a transmission message (I-Frame) is received from the terminal device 2, the IC card 1 transmits a reception confirmation notification when a timeout time elapses from the end of the received first frame. The IC card 1 notifying the reception confirmation changes (adjusts) the currently set timeout time AT0 by the time difference t between the time when the reception of the transmission message is completed and the time when the reception belief is transmitted according to the set timeout time. Judge whether to do.

For example, in the example illustrated in FIG. 4, when a 4-frame transmission message (I-Frame) is received from the terminal device 2 immediately after the communication establishment process in which WS is set to “4”, the time difference t is A ≦ t ≦ A + α. Therefore, the IC card 1 does not adjust the timeout time.
In the example shown in FIG. 4, when the 4-frame transmission message is received and then the 3-frame transmission message is received, the time difference t is t ≧ A + α. The timeout time AT0 is adjusted (updated) to a shorter time AT1.

In the example shown in FIG. 4, when a 3-frame transmission message is received after a 3-frame transmission message is received, A ≦ t ≦ A + α, so the IC card 1 does not adjust the timeout time. .
In the example shown in FIG. 4, when a 4-frame transmission message is received after adjusting the timeout time to AT1 in response to the reception of a 3-frame transmission message, the time difference t becomes t ≦ A. Changes the set value AT of the timeout time to the initial value AT0 of the timeout time.

  Note that the IC card 1 may transmit a reception confirmation before the transmission message of all frames can be received by shortening the timeout time. For example, in the example shown in FIG. 4, in the case of the timeout time AT1, a transmission message composed of 4 frames cannot be received. In this case, when the IC card 1 transmits the reception confirmation with the adjusted short timeout time, the time-out time is returned to the initial setting, and for the frame for which the reception confirmation is not notified, the timeout is performed after receiving the unreported frame. An acknowledgment is sent when the time has elapsed.

  In other words, in the example shown in FIG. 4, when the IC card 1 transmits a reception confirmation with a timeout time AT1 to a transmission message consisting of four frames, the IC card 1 changes the timeout time to the initial value AT0 and transmits the reception confirmation. When the timeout time AT0 has elapsed from the start of reception of the remaining frame that was being received, the reception confirmation of the remaining frame is transmitted to the terminal device 2.

Next, a processing example in the adjustment mode in the IC card 1 will be described.
FIG. 6 is a flowchart for explaining the flow of processing in the adjustment mode in the IC card 1.
First, the IC card 1 performs communication establishment processing in response to a reset request from the terminal device 2 (step S11). The terminal device 2 designates the WS setting value together with the reset request to the IC card 1. The CPU 11 of the IC card 1 sets the WS value specified for the terminal device 2. The CPU 11 sets the WS value by storing the WS value designated by the terminal device 2 in the working memory 13. When the WS value is set, the CPU 11 calculates an initial value AT0 of the timeout time AT according to the WS value. When calculating the initial value AT0 of the calculated timeout time, the CPU 11 stores the calculated initial value in the working memory 13 as the timeout time AT.

  When the communication establishment process is completed, the CPU 11 of the IC card 1 enters a state of waiting for a transmission message (frame) from the terminal device 2. When the transmission message is received from the terminal device 2 (step S12, YES), the CPU 11 of the IC card 1 measures the elapsed time from the completion of reception of the first frame in the transmission message received from the terminal device 2 by the timer 11a. The CPU 11 monitors whether or not the elapsed time counted by the timer 11a has reached the currently set timeout time stored in the working memory 13 (step S13).

  When receiving a transmission message, the CPU 11 monitors the completion of reception of the transmission message (step S14). When the reception of the transmission message is completed before the elapsed time measured by the timer 11a reaches the timeout time (step S14, YES), the CPU 11 determines that the elapsed time measured by the timer 11a from the time when the reception of the transmission message is completed is the timeout time. The time (time difference) t until it becomes is measured (step S15).

  When the elapsed time measured by the timer 11a becomes the timeout time (step S13, YES), the CPU 11 transmits a reception confirmation response to the received frame to the terminal device 2 (step S16). When transmitting the reception confirmation, the CPU 11 determines whether or not the operation mode of the timeout time in the communication with the terminal device 2 is the adjustment mode (step S17). When the adjustment mode is set (step S17, YES), the CPU 11 confirms whether or not all frames of the transmission message from the terminal device 2 have been received (step S18). When all the frames of the transmission message have not been received (step S18, NO), the CPU 11 returns the timeout time AT to the initial value AT0 (step S19). In this case, the CPU 11 returns to step S <b> 13 and executes reception processing for the remaining frames for which reception confirmation has not been transmitted.

  When it is confirmed that all the frames of the transmission message have been received (step S18, YES), the CPU 11 determines whether or not the time difference t from the completion of reception until the timeout time is equal to or greater than the first reference value A. (Step S20). When determining that the time difference t is less than the first reference value A (step S20, NO), the CPU 11 updates the timeout time AT to the initial value AT0 (step S21). In this case, the CPU 11 returns to step S12 and waits for reception of the next frame. The first reference value A is a time set according to the communication speed. For example, it is conceivable that the first reference value A is shorter than the reception time for one frame and longer than the time from the completion of frame reception until the transmission of the reception confirmation can be surely started.

  When the time difference t from completion of reception of all frames to transmission of reception confirmation is less than the first reference value A, the IC card 1 does not immediately return the timeout time to the initial value, but gradually times out. You may make it adjust so that time may be lengthened. For example, when the time difference t becomes less than the first reference value A, the CPU 11 may adjust the timeout time AT to a longer time by multiplying the timeout time AT by a magnification C larger than 1.

  If it is determined that the time difference t is equal to or greater than the first reference value A (step S20, YES), the CPU 11 further determines whether or not the time difference t is equal to or less than the second reference value (A + α) ( Step S22). When it is determined that the time difference t is equal to or smaller than the second reference value (A + α) (step S20, YES), the CPU 11 does not update the current timeout time AT stored in the working memory 13 and updates the current timeout time AT. Continue setting value of. In this case, the CPU 11 returns to step S12 and waits for reception of the next frame. The second reference value A + α is also a time set according to the communication speed. For example, α in the second reference value A + α is a time within a range in which the set value of the timeout time is allowed to continue.

  When it is determined that the time difference t is larger than the second reference value (A + α) (step S20, NO), the CPU 11 adjusts the current timeout time AT stored in the working memory 13 (step S23). For example, the CPU 11 updates the timeout time AT by multiplying the current timeout time AT stored in the working memory 13 by the magnification B. The CPU 11 can set the timeout time AT to a short value by setting the magnification B to 0 <B <1. For example, by setting the magnification B to 0.5 to 0.75, the timeout time can be shortened by 1/2 to 3/4.

  As described above, the IC card according to the embodiment has a time-out from completion of reception of the first frame to transmission of reception confirmation when the time difference between transmission of reception confirmation from completion of reception of all frames is longer than a predetermined reference time. Adjust the time to a shorter value. Thereby, it can suppress that waiting time until an IC card transmits reception confirmation becomes long.

  Further, the IC card shortens the time-out time each time if the time difference between the reception completion of the reception of all frames and the transmission of the reception confirmation is longer than the reference time. As a result, when reception of a frame number smaller than the set maximum continuous frame (WS) continues, the time-out time is gradually shortened to a time-out time suitable for the number of frames actually received. Can be adjusted. As a result, the time required for the entire communication process between the terminal device and the IC card can be shortened.

  As described above, the IC card according to the present embodiment interprets and executes an instruction from an external device, and responds with the result. The IC card and external device use a variable-length data format (frame) that specifies the maximum data length for data exchange. When there is no reception confirmation from one side or next frame transmission request, a frame is sent from the other side. Continuous transmission is possible. In addition, when the maximum value of the continuous transmission number of frames is set, in the communication system in which the reception confirmation or the next frame transmission request is waited after transmitting the maximum number of frames, the IC card or the terminal device until the reception confirmation is transmitted. The initial value of the time is set at the time of activation. In the frame exchange after setting the initial value, the IC card or the terminal device automatically adjusts the time until the reception confirmation transmission according to the time difference between the actual reception completion and the reception confirmation transmission.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... IC card, C ... Main body, 1a ... IC chip, 2 ... Terminal device (mobile phone, external device), 11 ... CPU, 11a ... Timer, 12 ... Program memory, 13 ... Working memory, 14 ... Data memory, 15 ... Communication control unit, 16 ... Power supply unit, 17 ... Interface, 31 ... Control unit, 32 ... RAM, 34 ... Non-volatile memory, 35 ... Interface.

Claims (8)

A portable electronic device,
A communication means for transmitting and receiving data composed of data in frame units;
A setting means for setting a maximum number of frames that can be received and an initial value of a response start time for starting a response to received data;
A response means for transmitting a reception confirmation of the data when a response start time for the data received by the communication means has elapsed;
Adjusting means for correcting the response start time according to the waiting time from the completion of reception of data by the communication means to the response start time for the data;
A portable electronic device comprising: The adjusting means shortens the response start time when the waiting time is longer than the first time.
The portable electronic device according to claim 1, wherein the portable electronic device is a portable electronic device. The adjusting means maintains the response start time when the waiting time is shorter than the first time and longer than the second time.
The portable electronic device according to claim 1, wherein the portable electronic device is a portable electronic device. The adjusting means returns the response start time to an initial value when the waiting time is shorter than a second time.
The portable electronic device according to any one of claims 1 to 3, wherein the portable electronic device is any one of the above. The adjusting means increases the response start time when the waiting time is shorter than a second time.
The portable electronic device according to any one of claims 1 to 3, wherein the portable electronic device is any one of the above. Furthermore, it has mode setting means for setting either an adjustment mode for adjusting the response start time by the adjustment means according to setting data received from an external device or a fixed mode for fixing the response start time to an initial value.
The portable electronic device according to claim 1, wherein the portable electronic device is a portable electronic device. An IC card,
Communication means for transmitting / receiving data composed of data in frame units, setting means for setting a maximum number of receivable frames and an initial value of a response start time for starting a response to the received data, and reception by the communication means A response unit that transmits a reception confirmation of the data when a response start time for the data has elapsed, and an adjustment that corrects the response start time according to the waiting time from the completion of reception of the data by the communication unit to the response start time for the data A module having means,
A body having the module;
An IC card characterized by comprising: A communication method used in a portable electronic device comprising:
Set the maximum number of frames that can be received and the initial value of the response start time for starting the response to the received data.
Receives data consisting of frame data,
When the response start time for the received data has passed, send a receipt confirmation of the data,
Correcting the response start time according to the waiting time from the completion of reception of the data to the response start time for the data,
A communication method used for a portable electronic device.

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