JP2008003811A - Information communication medium and communication condition control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information communication medium which is superior in switching efficiency of communication conditions (communication protocols and a communication rate). <P>SOLUTION: The information communication medium is made of a card main body having a module embedded thereinto, and the module includes: a storage means wherein an initial communication condition out of a plurality of communication conditions is stored; a communication means which communicates with an external device; and a control means which transmits the initial communication condition stored in the storage means to the external device through the communication means in response to reception of a request for a communication condition from the external device through the communication means and rewrites the initial communication condition stored in the storage means with a requested communication condition in response to reception of a request for communication condition change from the external device through the communication means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an information communication medium such as an IC card capable of switching communication conditions. The present invention also relates to a communication condition control method for controlling switching of communication conditions of an information communication medium.

  In recent years, IC cards with excellent safety have been widely used. Such an IC card includes a non-volatile memory that can retain data even when power supply is cut off, a communication I / F that can communicate with a reader / writer, a CPU that performs various operations, a CPU operation program, and the like. It has a ROM for storing data and a RAM for temporarily storing data (see Patent Document 1). In the RAM, for example, a communication protocol and a communication rate for communicating with the reader / writer are stored.

  When the IC card receives supply of Vcc, GND, CLK, RESET signal and the like necessary for activating the IC card, the IC card starts an activation sequence and outputs an ATR (answer to reset). At this time, a communication protocol and a communication rate performed after ATR transmission are stored in the RAM.

Thereafter, PPS exchange is performed between the reader / writer and the IC card, and when the PPS is exchanged normally, the communication protocol and communication rate are switched based on the information stored in the PPS. The rate is stored in RAM. That is, the IC card can indicate default communication conditions (communication protocol, communication rate) by ATR, and can switch communication conditions by PPS.
JP-A-9-231113

  As described above, conventionally, when it is necessary to switch the communication protocol and communication rate, after the card transmits ATR, the PPS is exchanged between the reader / writer and the IC card, and the communication protocol and communication rate are changed. Switching.

  However, even when connected to the same reader / writer each time, the same procedure must be followed to switch the communication protocol and communication rate, resulting in poor communication efficiency.

  An object of the present invention is to provide an information communication medium and a communication condition control method that are excellent in switching efficiency of communication conditions (communication protocol, communication rate).

  The information communication medium and communication condition control method of the present invention are configured as follows.

  (1) An information communication medium according to the present invention includes a card body in which a module is embedded. The module includes a storage unit that stores initial communication conditions among a plurality of communication conditions, and a communication unit that communicates with an external device. And receiving a request for communication conditions from the external device via the communication means, transmitting the initial communication conditions stored in the storage means to the external device via the communication means, and Control means for rewriting the initial communication condition stored in the storage means to the communication condition requested to be changed based on receiving a communication condition change request from the external device via the means.

  (2) The communication condition control method of the present invention receives a communication condition request from an external device, transmits an initial communication condition to the external device, and receives a communication condition change request from the external device. The initial communication condition is rewritten to the communication condition requested to be changed.

  According to the present invention, it is possible to provide an information communication medium and a communication condition control method excellent in switching efficiency of communication conditions (communication protocol, communication rate).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a communication system according to an embodiment of the present invention. As shown in FIG. 1, the communication system includes a communication terminal 1 and an IC card (information communication medium) 2.

  The communication terminal 1 includes a control unit 11, a display 12, a keyboard 13, a card reader / writer 14, and a numeric keypad 15. The control unit 11 executes various applications and inputs / outputs various data. The display 12 displays a result of communication with the IC card 2 and the like. The keyboard 13 inputs data such as characters and numbers to the control unit 11 in response to an input operation by the operator. The card reader / writer 14 receives data read from the IC card 2 and transmits data to be written to the IC card 2. The numeric keypad 15 inputs identification data such as a PIN to the control unit 11 in response to an input operation by the operator.

  As shown in FIG. 2, one IC card 2 includes a contact unit 21, a power supply circuit 23, a reception circuit 24, a transmission circuit 25, a control unit 26, a ROM 27, a RAM 28, and a nonvolatile memory 29. The contact unit 21 is connected to the card reader / writer 14 and receives a signal from the communication terminal 1 or transmits a signal to the communication terminal 1. That is, the contact unit 21 functions as an I / F for receiving Vcc, GND, CLK, and RESET signals necessary for activating the IC card and transmitting / receiving data to / from the communication terminal 1. The receiving circuit 24 outputs the data received from the communication terminal 1 to the control unit 26. The power supply circuit 23 stabilizes Vcc input from the contact unit 21 to generate operating power, and supplies this operating power to the control unit 26 and other circuit units. The transmission circuit 25 outputs transmission data from the control unit 26. The control unit 26 executes a command transmitted from the communication terminal 1. The RAM 28 temporarily stores processing results executed by the control unit 26. The ROM 27 stores a control program executed by the control unit 26 and the like. The non-volatile memory 29 holds the processing result executed by the control unit 26 even after the power supply from the power supply circuit 23 is cut off.

  For example, the ROM 27 stores a plurality of communication conditions (a plurality of communication protocols, a plurality of communication parameters (for example, a plurality of communication rates)) including initial communication conditions (communication protocol, communication parameters (for example, a communication rate)). . By switching the plurality of communication conditions on the IC card 2 side, communication with a plurality of communication terminals having different communication methods from the IC card 2 becomes possible. The RAM 28 stores communication conditions selected from a plurality of communication conditions stored in the ROM 27. For example, as shown in FIG. 3, the RAM 28 stores a communication protocol 281 to be communicated with the communication terminal 1 and a communication parameter (communication rate 282) to be communicated with the communication terminal 1. As shown in FIG. 4, the non-volatile memory 29 stores an ATR value 291 to be output after COLD reset. The COLD reset will be described in detail later.

  Next, communication between the communication terminal 1 and the IC card 2 will be described with reference to flowcharts shown in FIGS. FIG. 5 is a flowchart showing an example of the first communication process (ATR rewriting is possible) between the communication terminal 1 and the IC card 2, and FIG. 6 shows the communication conditions rewritten in the first communication process. 5 is a flowchart for explaining an example of communication processing (ATR rewritable) after the second time between the communication terminal 1 and the IC card 2.

  As shown in FIG. 5, the communication terminal 1 supplies the Vcc, GND, CLK, and RESET signals to the contact unit 21 of the IC card 2 and activates the activation sequence (ST101). The relationship between the power supply level (Vcc) and the RESET signal (RST) at this time is Vcc: low level (L) → high level (H), and RST: low level (L) → high level (H). That is, the reset that satisfies the relationship between the start of power supply and the output of the reset signal is referred to as COLD_RESET as shown in FIG.

  When the activation sequence is activated from the communication terminal 1, the IC card 2 performs start-up processing so that it can operate, reads the ATR value (initial communication condition (initial value)) from the nonvolatile memory 29, and uses the ATR value as the communication terminal. Send to 1. At the same time, the communication protocol to be communicated and the communication rate are determined from the ATR value stored in the nonvolatile memory 29, and stored in the RAM 28 (ST102).

  Based on the ATR value, communication terminal 1 (control unit 11) determines a communication protocol (first presentation protocol) and communication rate (value of TA1) to be communicated (ST103). When the communication terminal 1 determines that communication is possible based on these communication protocols and communication rates (ST104, NO), it starts communication using these communication protocols and communication rates, and an application is executed between the communication terminal 1 and the IC card 2. When the execution is completed, the IC card 2 is deactivated.

  Conversely, when the communication terminal 1 determines that communication is impossible due to these communication protocols and communication rates, it supplies a RESET signal. The relationship between the power supply level (Vcc) and the RESET signal (RST) at this time is Vcc: high level (H) → high level (H), and RST: low level (L) → high level (H). That is, the reset that satisfies the relationship between the continuation of power supply and the reset signal re-output is referred to as WARM_RESET as shown in FIG. The IC card 2 writes the ATR value back to the initial value based on WARM_RESET. In this case, the ATR value stored in the nonvolatile memory 29 is an initial value (initial communication condition), and the ATR value is substantially unchanged. Therefore, even if communication is attempted again, a communication error occurs (multiple communication errors). As a result, the communication terminal 1 determines that communication is impossible due to multiple communication errors (ST104, YES), transmits a PPS request (ST105), and requests a change in communication conditions, for example, a change in communication rate.

  The IC card 2 checks the PPS request received from the communication terminal 1 and determines whether it is valid or invalid (ST106). When the IC card 2 determines that the PPS request is valid (ST106, YES), a PPS response is transmitted. At the same time, based on the PPS request, after transmitting the PPS response, the communication protocol and communication rate to be communicated are determined, and these communication protocol and communication rate are stored in the RAM 28 (ST107). At the same time, the ATR value (initial communication condition (initial value)) of the nonvolatile memory 29 is rewritten to the communication protocol and communication rate stored in the RAM 28. That is, the first presentation protocol and TA1 are rewritten. If the PPS request is invalid, the communication protocol and communication rate are not changed. Thereafter, the application is executed between the communication terminal 1 and the IC card 2, and when the execution is completed, the IC card 2 is deactivated.

  If it is activated again (ST101) and communication is possible with the same communication protocol and communication rate as the previous time, the processing for changing the communication protocol and communication rate is omitted by the PPS request and the PPS response. That is, when communication is possible under the same initial communication conditions as in the previous time (when the communication conditions were not rewritten last time), the initial communication conditions are stored in the nonvolatile memory 29, and the nonvolatile memory 29 The initial communication condition stored in is used. Further, when communication is possible under the same rewritten communication condition as the previous time (when the communication condition is rewritten last time), the rewritten communication condition is stored in the non-volatile memory 29. The rewritten communication condition stored in 29 is used.

  Next, referring to FIG. 6, the communication condition is rewritten in the first communication process described above, and an example of the second and subsequent communication processes between the communication terminal 1 and the IC card 2 is described in more detail. explain. As shown in FIG. 6, the communication terminal 1 supplies the Vcc, GND, CLK, and RESET signals to the contact unit 21 of the IC card 2 and activates the activation sequence (ST201). The relationship between the power supply level (Vcc) and the RESET signal (RST) at this time is Vcc: low level (L) → high level (H), and RST: low level (L) → high level (H). That is, the reset that satisfies the relationship between the start of power supply and the output of the reset signal is referred to as COLD_RESET as shown in FIG.

  When the activation sequence is activated from the communication terminal 1, the IC card 2 performs a startup process so that it can operate, reads the rewritten ATR value (rewritten communication condition) from the nonvolatile memory 29, and the ATR value Is transmitted to the communication terminal 1. At the same time, the communication protocol and communication rate to be communicated are determined from the rewritten ATR value stored in the nonvolatile memory 29, and stored in the RAM 28 (ST202).

  Communication terminal 1 (control unit 11) determines a communication protocol and a communication rate to be communicated based on the ATR value (ST203). If the communication terminal 1 determines that communication is possible based on these communication protocols and communication rates (rewritten communication conditions) (NO in ST204), the communication terminal 1 starts communication using these communication protocols and communication rates, and the communication terminal 1 and the IC card 2 When the application is executed in between, and the execution is completed, the IC card 2 is deactivated.

  Conversely, when communication terminal 1 determines that communication is impossible based on these communication protocols and communication rates (rewritten communication conditions) (ST204, YES), it supplies a RESET signal (ST205). The relationship between the power supply level (Vcc) and the RESET signal (RST) at this time is Vcc: high level (H) → high level (H), and RST: low level (L) → high level (H). That is, the reset that satisfies the relationship between the continuation of power supply and the reset signal re-output is referred to as WARM_RESET as shown in FIG.

  The IC card 2 writes the rewritten ATR value back to the initial value based on WARM_RESET (ST206). That is, the rewritten ATR value (rewritten communication condition) stored in the nonvolatile memory 29 is written back to the initial value (initial communication condition).

  Thereafter, the IC card 2 performs startup processing so that it can operate, reads the ATR value (initial communication condition (initial value)) from the nonvolatile memory 29, and transmits the ATR value to the communication terminal 1. At the same time, the communication protocol to be communicated and the communication rate are determined from the ATR value stored in the nonvolatile memory 29, and stored in the RAM 28 (ST207).

  Communication terminal 1 (control unit 11) determines a communication protocol (first presentation protocol) and a communication rate (value of TA1) to be communicated based on the ATR value (ST208). When the communication terminal 1 determines that communication is possible based on these communication protocols and communication rates (ST209, NO), communication using these communication protocols and communication rates is started, and an application is executed between the communication terminal 1 and the IC card 2, When the execution is completed, the IC card 2 is deactivated.

  Conversely, the communication terminal 1 determines that communication is impossible due to multiple communication errors (ST209, YES), transmits a PPS request (ST210), and requests a change in communication conditions, for example, a change in communication rate.

  The IC card 2 checks the PPS request received from the communication terminal 1 and determines whether it is valid or invalid (ST211). If the IC card 2 determines that the PPS request is valid (ST211, YES), it transmits a PPS response. At the same time, based on the PPS request, after transmitting the PPS response, the communication protocol and communication rate to be communicated are determined, and the communication protocol and communication rate are stored in the RAM 28 (ST212). At the same time, the ATR value (initial communication condition (initial value)) of the nonvolatile memory 29 is rewritten to the communication protocol and communication rate stored in the RAM 28. That is, the first presentation protocol and TA1 are rewritten. If the PPS request is invalid, the communication protocol and communication rate are not changed. Thereafter, the application is executed between the communication terminal 1 and the IC card 2, and when the execution is completed, the IC card 2 is deactivated.

  Next, a case where the ATR value cannot be rewritten will be described. FIG. 8 is a flowchart illustrating an example of communication processing in which the ATR value cannot be rewritten.

  As shown in FIG. 8, the communication terminal supplies the Vcc, GND, CLK, and RESET signals to the IC card, and activates the activation sequence (ST301).

  When the activation sequence is activated from the communication terminal, the IC card performs a startup process so that it can operate, reads the ATR value (initial communication condition (initial value)) from the nonvolatile memory, and transmits the ATR value to the communication terminal. . At the same time, the communication protocol and communication rate to be communicated are determined from the ATR value stored in the nonvolatile memory, and stored in the RAM (ST302).

  Based on the ATR value, the communication terminal determines the communication protocol to be communicated (first presentation protocol) and the communication rate (value of TA1) (ST303). When the communication terminal determines that communication is possible based on these communication protocols and communication rates (ST304, NO), the communication terminal starts communication using these communication protocols and communication rates, and when the application is executed between the communication terminal and the IC card, the execution ends. The IC card is deactivated.

  Conversely, when the communication terminal determines that communication is impossible based on these communication protocols and communication rates (ST304, YES), the communication terminal transmits a PPS request (ST305) and requests a change in communication conditions, for example, a change in communication rate.

  The IC card checks the PPS request received from the communication terminal and determines whether it is valid or invalid (ST306). If the IC card determines that the PPS request is valid (ST306, YES), it transmits a PPS response. At the same time, based on the PPS request, after transmitting the PPS response, the communication protocol and communication rate to be communicated are determined, and the communication protocol and communication rate are stored in the RAM (ST307). If the PPS request is invalid, the communication protocol and communication rate are not changed. Thereafter, the application is executed between the communication terminal and the IC card, and when the execution is completed, the IC card is deactivated.

  If it is activated again (ST301), the initial communication condition stored in the non-volatile memory 29 can be used only when communication is possible under the initial communication condition (communication condition change processing is performed). Unnecessary), when communication is possible under the same changed communication conditions as the previous time, the initial communication conditions stored in the non-volatile memory 29 cannot be used, and it is necessary to change the communication conditions again. Become. That is, in such a case, it is necessary to follow the same sequence of ATR transmission and PPS exchange every activation.

  The present embodiment will be summarized below.

  The IC card 2 stores the previously changed communication conditions (communication protocol and communication rate) in the nonvolatile memory 29 and uses the communication conditions initially stored in the nonvolatile memory 29 in the current communication. More specifically, the IC card 2 presents the communication condition (previous communication condition) stored in the nonvolatile memory 29 based on COLD_RESET, and the communication condition (previous communication condition) stored in the nonvolatile memory 29 based on WARM_RESET. (Communication condition) is written back to the initial communication condition, and the written initial communication condition is presented. This eliminates the need to change the communication conditions when communication is possible under the same communication conditions as the previous time. If communication is not possible under the same communication conditions as the previous time, communication is tried according to the initial communication conditions (also in this case, the change process). Is not required). If communication is impossible even with the initial communication condition written back, a process for changing the communication condition is executed.

  Conventionally, even when an IC card is connected to the same terminal as the previous one and communicates with the same communication protocol and communication rate, a procedure for PPS exchange between the terminal and the IC card is necessary, and the same procedure is followed each time. There was a need. According to the present embodiment, when the PPS exchange is successful, when the communication protocol and communication rate are activated next time by rewriting the ATR value so that the communication protocol and communication rate become the first presentation protocol, It becomes a communication rate. Thereby, the PPS exchange can be omitted.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

FIG. 1 is a diagram showing a schematic configuration of a communication system according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of an IC card according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of data stored in the RAM of the IC card. FIG. 4 is a diagram illustrating an example of data stored in the nonvolatile memory of the IC card. FIG. 5 is a flowchart showing an example of the first communication process (ATR rewriting is possible) between the communication terminal and the IC card. FIG. 6 is a flowchart for explaining an example of the second and subsequent communication processes (ATR rewrite is possible) between the communication terminal and the IC card after the communication conditions are rewritten in the first communication process. FIG. 7 is a diagram for explaining COLD_RESET and WARM_RESET. FIG. 8 is a flowchart illustrating an example of communication processing in which the ATR value cannot be rewritten.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Communication terminal, 2 ... IC card (information communication medium), 11 ... Control part, 12 ... Display, 13 ... Keyboard, 14 ... Card reader / writer, 15 ... Numeric keypad, 21 ... Contact part, 23 ... Power supply circuit, 24 ... Receiving circuit 25 ... Transmitting circuit 26 ... Control unit 27 ... ROM 28 ... RAM 29 ... Non-volatile memory

Claims (9)

An information communication medium composed of a card body in which a module is embedded,
The module is
Storage means for storing an initial communication condition among a plurality of communication conditions;
A communication means for communicating with an external device;
A request for communication conditions from the external device is received via the communication means, the initial communication conditions stored in the storage means are transmitted to the external device via the communication means, and the communication means is Control means for rewriting the initial communication condition stored in the storage means to the communication condition requested to be changed based on receiving the communication condition change request from the external device via
An information communication medium comprising:   The information communication medium according to claim 1, wherein the communication unit transmits the rewritten communication condition rewritten in response to the request for the communication condition received after rewriting the communication condition.   The control means writes back the rewrite communication condition stored in the storage means to the initial communication condition based on reception of a communication error under the rewrite communication condition via the communication means, and via the communication means The information communication medium according to claim 2, wherein the written initial communication condition is transmitted. An information communication medium composed of a card body in which a module is embedded,
The module is
Storage means for storing an initial communication condition among a plurality of communication conditions;
A communication means for communicating with an external device;
The initial communication received from the external device via the communication means and stored in the storage means for the external device via the communication means based on the power supply start and reset signal output Control means for transmitting a condition and rewriting the initial communication condition stored in the storage means to the communication condition requested to be changed based on receiving a request for changing the communication condition from the external device via the communication means When,
An information communication medium comprising:   5. The information communication medium according to claim 4, wherein the communication means transmits the rewritten communication condition rewritten in response to the activation request received after rewriting the communication condition.   The control means changes the rewrite communication condition stored in the storage means to the initial communication condition based on continuation of power supply upon reception of a communication error under the rewrite communication condition via the communication means and reset signal re-output. 6. The information communication medium according to claim 5, wherein the initial communication condition written back and transmitted via the communication means is transmitted. Receives communication condition requests from external devices,
Send initial communication conditions to the external device,
Rewriting the initial communication condition to the requested communication condition based on receiving the communication condition change request from the external device,
A communication condition control method characterized by the above.   8. The communication condition control method according to claim 7, wherein the rewritten communication condition that has been rewritten is transmitted in response to the request for the communication condition received after rewriting the communication condition.   9. The communication condition control method according to claim 8, wherein the rewritten communication condition is written back to the initial communication condition based on reception of a communication error in the rewritten communication condition, and the rewritten initial communication condition is transmitted. .

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