JP2024173086A - ELECTRONIC INFORMATION STORAGE MEDIUM, IC CHIP, IC CARD, COMMUNICATION PARAMETER TRANSMISSION METHOD, AND PROGRAM - Google Patents

Abstract

[Problem] To provide an electronic information storage medium, an IC chip, an IC card, a communication parameter transmission method, and a program capable of presenting two types of communication parameters corresponding to two types of standby states to an external device. [Solution] An IC chip 1 transmits information indicating a communication parameter CPI to an external device 2 by a response signal when starting communication from an IDLE state, and transmits information indicating a communication parameter CPH to an external device 2 by a response signal when starting communication from a HALT state. [Selected Figure] Figure 8

Description

The present invention relates to the technical field of contactless IC (Integrated Circuit) cards that are capable of contactless communication with external devices.

Conventionally, two types of standby states, IDLE and HALT, have been known for contactless IC cards conforming to ISO/IEC14443-3 to wait for communication with an external device. For example, when a Type-B contactless IC card starts communication with an external device in the IDLE or HALT state, it transmits pre-stored communication parameters to the external device by ATQB (Answer To reQuest for PICC B) in response to a WUPB (Wake Up command Type B) from the external device. For example, the contactless IC card disclosed in Patent Document 1 stores multiple communication conditions including initial communication conditions, and is able to communicate with multiple communication terminals with different communication methods by switching between these multiple communication conditions on the contactless IC card side.

JP 2008-276572 A

However, in conventional technologies including Patent Document 1, the external device cannot switch communication parameters (such as maximum frame size) between when starting communication with the contactless IC card from an IDLE state and when starting communication from a HALT state.

The present invention has been made in consideration of the above-mentioned points as an example of the problem, and aims to provide an electronic information storage medium, an IC chip, an IC card, a communication parameter transmission method, and a program that are capable of presenting two types of communication parameters corresponding to two types of standby states to an external device.

In order to solve the above problem, the invention described in claim 1 is an electronic information storage medium capable of communicating with an external device, comprising: a storage means for storing information indicating a first communication parameter when communication with the external device is started from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when communication with the external device is started from a second standby state in which communication with the external device is waited for and different from the first standby state; and a transmission means for transmitting information indicating the first communication parameter to the external device when communication is started from the first standby state, and transmitting information indicating the second communication parameter to the external device when communication is started from the second standby state. The electronic information storage medium is characterized by comprising: a storage means for storing information indicating a first communication parameter when communication with the external device is started from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when communication with the external device is started from a second standby state in which communication with the external device is waited for and different from the first standby state.

The invention described in claim 2 is characterized in that in the electronic information storage medium described in claim 1, the information indicating the communication parameters includes information indicating at least one of the maximum frame size, maximum waiting time, and communication speed.

The invention described in claim 3 is characterized in that, in the electronic information storage medium described in claim 1, the information indicating the first communication parameters includes information indicating the first standby state, and the information indicating the second communication parameters includes information indicating the second standby state.

The invention described in claim 4 is characterized in that, in the electronic information storage medium described in any one of claims 1 to 3, the communication is non-contact communication, the first standby state is an IDLE state, and the second standby state is a HALT state.

The invention described in claim 5 is an IC chip capable of communicating with an external device, comprising: a storage means for storing information indicating a first communication parameter when communication with the external device is started from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when communication with the external device is started from a second standby state in which communication with the external device is waited for and different from the first standby state; and a transmission means for transmitting information indicating the first communication parameter to the external device when communication is started from the first standby state, and transmitting information indicating the second communication parameter to the external device when communication is started from the second standby state.

The invention described in claim 6 is an IC card capable of communicating with an external device, comprising: a storage means for storing information indicating a first communication parameter when communication with the external device is started from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when communication with the external device is started from a second standby state in which communication with the external device is waited for and different from the first standby state; and a transmission means for transmitting information indicating the first communication parameter to the external device when communication is started from the first standby state, and transmitting information indicating the second communication parameter to the external device when communication is started from the second standby state.

The invention described in claim 7 is a communication parameter transmission method executed by an electronic information storage medium capable of communicating with an external device, characterized in that it includes a step of storing information indicating a first communication parameter when communication with the external device is started from a first standby state in which the communication with the external device is waited for, and information indicating a second communication parameter when the communication with the external device is started from a second standby state in which the communication with the external device is waited for and different from the first standby state, and a step of transmitting information indicating the first communication parameter to the external device when the communication is started from the first standby state, and transmitting information indicating the second communication parameter to the external device when the communication is started from the second standby state.

The invention described in claim 8 is characterized in that the computer included in an electronic information storage medium capable of communicating with an external device is caused to execute the steps of storing information indicating a first communication parameter when communication with the external device is started from a first standby state in which the communication with the external device is waited for, and information indicating a second communication parameter when the communication with the external device is started from a second standby state in which the communication with the external device is waited for and different from the first standby state, and transmitting information indicating the first communication parameter to the external device when the communication is started from the first standby state, and transmitting information indicating the second communication parameter to the external device when the communication is started from the second standby state.

The invention described in claim 9 is an electronic information storage medium capable of communicating with an external device, the electronic information storage medium having a memory that stores at least information indicating default communication parameters used in communication with the external device, the electronic information storage medium comprising a first determination means for determining whether a current state of the electronic information storage medium is a first standby state in which communication with the external device is awaited, or a second standby state in which communication with the external device is awaited and different from the first standby state, and, when it is determined that the current state is the first standby state, determining whether information indicating first communication parameters for starting the communication from the first standby state is stored in the memory, while, when it is determined that the current state is the second standby state, determining whether information indicating first communication parameters for starting the communication from the second standby state is stored in the memory. The communication device includes a second determination means for determining whether information indicating a second communication parameter is stored in the memory, a first transmission means for transmitting information indicating the default communication parameter to the external device when it is determined that the information indicating the first communication parameter is not stored in the memory, and transmitting information indicating the first communication parameter to the external device when it is determined that the information indicating the first communication parameter is stored in the memory, and a second transmission means for transmitting information indicating the default communication parameter to the external device when it is determined that the information indicating the second communication parameter is not stored in the memory, and transmitting information indicating the second communication parameter to the external device when it is determined that the information indicating the second communication parameter is stored in the memory.

The invention described in claim 10 is a communication parameter transmission method executed by an electronic information storage medium capable of communicating with an external device, the electronic information storage medium having a memory that stores at least information indicating default communication parameters used in communication with the external device, the method including the steps of determining whether the current state of the electronic information storage medium is a first standby state in which the electronic information storage medium is waiting for communication with the external device, or a second standby state in which the electronic information storage medium is waiting for communication with the external device and is different from the first standby state, and, if it is determined that the current state is the first standby state, determining whether information indicating first communication parameters for starting the communication from the first standby state is stored in the memory, while, if it is determined that the current state is the second standby state, determining whether information indicating first communication parameters for starting the communication from the second standby state is stored in the memory, The method includes a step of determining whether information indicating a second communication parameter for starting the communication is stored in the memory, a step of transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the first communication parameters is not stored in the memory, and a step of transmitting information indicating the first communication parameters to the external device when it is determined that the information indicating the first communication parameters is stored in the memory, and a step of transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the second communication parameters is not stored in the memory, and a step of transmitting information indicating the second communication parameters to the external device when it is determined that the information indicating the second communication parameters is stored in the memory.

The invention described in claim 11 is an electronic information storage medium capable of communicating with an external device, the electronic information storage medium having a memory that stores at least information indicating default communication parameters used in communication with the external device, the electronic information storage medium including a computer that determines whether the current state of the electronic information storage medium is a first standby state in which communication with the external device is awaited, or a second standby state in which communication with the external device is awaited and different from the first standby state, and when it is determined that the current state is the first standby state, it determines whether information indicating first communication parameters for starting the communication from the first standby state is stored in the memory, while when it is determined that the current state is the second standby state, it determines whether information indicating first communication parameters for starting the communication from the second standby state is stored in the memory. The method includes the steps of: determining whether information indicating a second communication parameter is stored in the memory when the first communication parameter is to be used; transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the first communication parameters is not stored in the memory; transmitting information indicating the first communication parameters to the external device when it is determined that the information indicating the second communication parameters is not stored in the memory; transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the second communication parameters is not stored in the memory; and transmitting information indicating the second communication parameters to the external device when it is determined that the information indicating the second communication parameters is stored in the memory.

According to the present invention, two types of communication parameters corresponding to two types of standby states can be presented to an external device.

FIG. 2 is a diagram illustrating an example of a hardware configuration of an IC chip 1. 1A is a diagram showing an example of a memory map of a record area in NVM 13 of an IC chip 1 that adopts Type A as a communication method, which stores information indicating communication parameters; and FIG. 1B is a diagram showing an example of a memory map of a record area in NVM 13 of an IC chip 1 that adopts Type B as a communication method, which stores information indicating communication parameters. FIG. 1 is a diagram showing an example of an ATQA coding configuration. FIG. 2 is a diagram showing an example of an encoding configuration of an ATS. FIG. 13 is a diagram showing an example of an encoding configuration of ATQB. FIG. 1 is a diagram showing state transitions of an IC chip 1 that employs Type A as a communication method. FIG. 1 is a diagram showing state transitions of an IC chip 1 that employs Type B as a communication method. 10 is a flowchart showing an example of a communication parameter transmission process executed by a CPU 15 of the IC chip 1.

The following describes in detail an embodiment of the present invention with reference to the drawings.

[1. Configuration and Function of IC Chip 1]
First, the configuration and functions of an IC chip 1 according to this embodiment will be described with reference to FIG. 1. The IC chip 1 is an example of an electronic information storage medium capable of communicating with an external device 2. The IC chip 1 is mounted on, for example, an IC card such as a credit card, a cash card, or a My Number card, or a mobile device such as a smartphone. In the case of a mobile device such as a smartphone, the IC chip 1 may be mounted on a small IC card that is detachable from the mobile device, or may be mounted on an embedded board as an eUICC (Embedded Universal Integrated Circuit Card) so that it cannot be easily removed or replaced from the mobile device. The IC card or mobile device is provided with an antenna used for contactless communication.

1 is a diagram showing an example of the hardware configuration of an IC chip 1. As shown in FIG. 1, the IC chip 1 includes an I/O circuit 11, a RAM (Random Access Memory) 12, a NVM (Nonvolatile Memory) 13 (an example of a storage means), a ROM (Read Only Memory) 14, and a CPU (Central Processing Unit) 15 (an example of a computer), and complies with ISO/IEC 14443, an international standard for contactless communication. A unique UID (Unique IDentifier) is stored in the IC chip 1. The I/O circuit 11 serves as an interface with an external device 2. The IC chip 1 performs contactless communication with the external device 2 via the I/O circuit 11 and an antenna (not shown). As an example of a communication method related to such contactless communication, Type A and Type B standardized in ISO/IEC 14443 are taken. The I/O circuit 11 is connected to the antenna and includes a power (power supply) supply circuit 11a, a clock generation circuit 11b, and a modulation/demodulation circuit 11c. The antenna has an antenna coil, receives a carrier wave (electromagnetic wave) emitted from an external device 2 (reader/writer), and transmits a modulated signal output from the modulation/demodulation circuit 11c as an electromagnetic wave.

The power supply circuit 11a rectifies and smoothes the induced current related to the power (induced electromotive force) induced by the carrier wave received by the antenna, and supplies power to the CPU 15, etc. The clock generation circuit 11b generates an internal clock from the induced current related to the power induced by the carrier wave received by the antenna, and outputs it to the CPU 15, etc. The modulation and demodulation circuit 11c demodulates data from the carrier wave received by the antenna and outputs it to the CPU 15. The modulation and demodulation circuit 11c also modulates data from the CPU 15 and outputs it to the antenna as a modulated signal. Examples of the external device 2 include a transaction device equipped with a reader/writer and a data writing device.

For example, a flash memory is applied to the NVM 13. The NVM 13 may be an "Electrically Erasable Programmable Read-Only Memory". An OS (Operating System) and one or more applications (including the program of the present invention) are stored in the NVM 13 or the ROM 14. The program of the present invention can be downloaded from a data writing device. The CPU 15 executes the OS and the application (including the program of the present invention) stored in the NVM 13, thereby functioning as the first determination means, second determination means, transmission means, first transmission means, and second transmission means of the present invention.

The NVM 13 also stores at least information indicating default communication parameters used in communication with the external device 2. Hereinafter, the default communication parameters will be referred to as "communication parameters CPD" when distinguishing them from other communication parameters. The communication parameters CPD are standard communication parameters that are also stored in conventional contactless IC cards. Note that the information indicating the communication parameters may be a value representing the communication parameters themselves, or a bit string capable of identifying the communication parameters (same below).

Furthermore, in the NVM 13, information indicating communication parameters when communication is started from an IDLE state (an example of a first standby state) in which communication with the external device 2 is awaited, and information indicating communication parameters when the communication is started from a HALT state (an example of a second standby state) in which communication with the external device 2 is awaited, are stored, for example, by settings according to a setting command from the outside. Here, when the communication parameters when communication is started from the IDLE state (communication parameters corresponding to the IDLE state) are distinguished from other communication parameters, they are hereinafter referred to as "communication parameters CPI". When the communication parameters when communication is started from the HALT state (communication parameters corresponding to the HALT state) are distinguished from other communication parameters, they are hereinafter referred to as "communication parameters CPH". In this way, it is possible to present (i.e., present at different times) two types of communication parameters corresponding to two types of standby states, the IDLE state and the HALT state, to the external device 2. Therefore, the external device 2 can appropriately select the communication parameter that is more suitable for the external device 2 (e.g., taking into consideration the communication performance of the external device 2) from the two types of communication parameters presented at different times, and communicate with the IC chip 1.

2A is a diagram showing an example of a memory map of a record area that stores information indicating communication parameters in the NVM 13 of an IC chip 1 that adopts Type A as a communication method. FIG. 2B is a diagram showing an example of a memory map of a record area that stores information indicating communication parameters in the NVM 13 of an IC chip 1 that adopts Type B as a communication method. The record area is divided into multiple areas, and the physical addresses of each record area are different. Information (data) stored in the record area is called a record. A record number is assigned to each record and associated with a physical address. Each record is logically stored (e.g., a record number is stored) in one or more files (e.g., EF (Elementary File)) and is managed by, for example, an application. A unique SFI (Short File Identifier) is assigned to each file. Note that the information consisting of "1" and "0" (i.e., information indicating communication parameters) in FIGS. 2A and 2B is merely an example.

First, in Type A, as shown in FIG. 2A, the NVM 13 stores, as the communication parameters CPD, CPI, and CPH, information indicating the maximum frame size (FSC: Frame Size for proximity Card), communication speed (DS: Divisor Send), communication speed (DR: Divisor Receive), maximum waiting time (FWT: Frame Waiting Time), start-up frame guard time (SFGT: Start-up Frame Guard Time), and the size of the UID of the IC chip 1 as respective records. Note that the information indicating the communication parameter CPD, the information indicating the communication parameter CPI, and the information indicating the communication parameter CPH may be managed by different files. For example, the information indicating the communication parameter CPD may be managed by a file with SFI "001", the information indicating the communication parameter CPI may be managed by a file with SFI "002", and the information indicating the communication parameter CPH may be managed by a file with SFI "003".

Here, the maximum frame size (FSC), communication speed (DS), communication speed (DR), maximum waiting time (FWT), start frame guard time (SFGT), and the size of the UID of the IC chip 1 are each referred to as an element of the communication parameters. The communication speed (DS) is the communication speed from the IC chip 1 to the external device 2, and the communication speed (DR) is the communication speed from the external device 2 to the IC chip 1. In the example of FIG. 2(A), the information indicating each element (i.e., the maximum frame size (FSC), communication speed (DS), communication speed (DR), maximum waiting time (FWT), ...) is different between the communication parameters CPD, CPI, and CPH. However, the information indicating some elements (e.g., the communication speed (DS)) between the communication parameters CPD, CPI, and CPH may be the same (e.g., all may be "001"), and in this case, such information may be stored in the same record area (i.e., the same address) of the NVM 13. Furthermore, in the NVM 13 shown in FIG. 2(A), information indicating the type of standby state (i.e., whether it is an IDLE state or a HALT state) as one element of the communication parameters CPI and CPH is stored as each record.

Next, in Type B, as shown in FIG. 2B, the NVM 13 stores, as the communication parameters CPD, CPI, and CPH, information indicating the communication speed capability (an example of communication speed, BRC: Bit Rate Capacity), maximum frame size (FSC), maximum waiting time (FWT), and start frame guard time (SFGT) as respective records. In this case, the information indicating the communication parameter CPD, the information indicating the communication parameter CPI, and the information indicating the communication parameter CPH may be managed by different files. Also, in the example of FIG. 2B, the information indicating each element is different between the communication parameters CPD, CPI, and CPH. However, the information indicating some elements may be the same between the communication parameters CPD, CPI, and CPH, and in this case, such information may be stored in the same record area of the NVM 13. Note that this embodiment can also be used with an IC chip 1 in which information indicating at least one of the communication parameters CPI and the communication parameter CPH is not stored in the NVM 13. If information indicating at least one of the communication parameters CPI and CPH is not stored in NVM13, information indicating the communication parameter CPD is used instead. On the other hand, if information indicating both the communication parameters CPI and CPH is stored in NVM13, the information indicating the communication parameter CPD is not used, and therefore the information indicating the communication parameter CPD may be deleted.

The information indicating the communication parameters described above is transmitted from the IC chip 1 to the external device 2 when communication with the external device 2 is started. For example, in the case of an IC chip 1 that adopts Type A as the communication method, the information indicating the communication parameters is transmitted in an ATQA (Answer To reQuest for PICC A) or an ATS (Answer To Select). On the other hand, in the case of an IC chip 1 that adopts Type B as the communication method, the information indicating the communication parameters is transmitted in an ATQB (Answer To reQuest for PICC B). ATQA, ATS, and ATQB are response signals (responses) to the external device 2. FIG. 3 is a diagram showing an example of the coding configuration of ATQA (standard format defined in ISO/IEC14443-3). For example, when the IC chip 1 starts communication from an IDLE state, information indicating the size of the UID of the IC chip 1 (for example, "01") among the elements included in the communication parameter CPI is set to bits b7 and b8 in the ATQA shown in FIG. 3. On the other hand, when IC chip 1 starts communication from a HALT state, information indicating the size of IC chip 1's UID (e.g., "10") among the elements included in the communication parameter CPH is set to bits b8 and b7 in the ATQA shown in Figure 3.

Figure 4 is a diagram showing an example of the coding structure of the ATS (standard format defined in ISO/IEC14443-3). For example, when the IC chip 1 starts communication from an IDLE state, information indicating the maximum frame size (FSC) (e.g., "1100") among the elements included in the communication parameter CPI is set in FSCI (bits b4 to b1) in T0 (format byte) in the ATS shown in Figure 4. Also, when communication is started from an IDLE state, information indicating the communication speed (DS) and communication speed (DR) among the elements included in the communication parameter CPI is set in DS (bits b7 to b5) and DR (bits b3 to b1) in TA(1) (interface byte) in the ATS shown in Figure 4. Furthermore, when communication is started from the IDLE state, information indicating the maximum waiting time (FWT) and the start frame guard time (SFGT) among the elements included in the communication parameters CPI is set in the FWI (bits b8 to b5) and SFGI (bits b4 to b1) in TB(1) (interface byte) in the ATS shown in Figure 4. Furthermore, when communication is started from the IDLE state, information indicating the waiting state type (IDLE state) among the elements included in the communication parameters CPI is set in one of the bits in T1 to Tk (historical bytes) in the ATS shown in Figure 4.

On the other hand, for example, when the IC chip 1 starts communication from a HALT state, information indicating the maximum frame size (FSC) (for example, "1111") among the elements included in the communication parameters CPH is set in FSCI (bits b4 to b1) in T0 in the ATS shown in FIG. 4. Also, when communication is started from a HALT state, information indicating the communication speed (DS) and communication speed (DR) among the elements included in the communication parameters CPH are set in DS (bits b7 to b5) and DR (bits b3 to b1) in TA(1) in the ATS shown in FIG. 4. Also, when communication is started from a HALT state, information indicating the maximum waiting time (FWT) and start frame guard time (SFGT) among the elements included in the communication parameters CPH are set in FWI (bits b8 to b5) and SFGI (bits b4 to b1) in TB(1) in the ATS shown in FIG. 4. In addition, when starting communication from a HALT state, information indicating the type of standby state (HALT state) among the elements included in the communication parameters CPH is set to one of the bits T1 to Tk in the ATS shown in Figure 4.

Figure 5 is a diagram showing an example of the coding configuration of ATQB (extended format defined in ISO/IEC14443-3). For example, when the IC chip 1 starts communication from the IDLE state, information indicating the communication speed capability (BRC) (for example, "00000010") among the elements included in the communication parameter CPI is set to BRC (bits b8 to b1) in the 10th byte in the protocol information in ATQB shown in Figure 5. Also, when communication is started from the IDLE state, information indicating the maximum frame size (FSC) among the elements included in the communication parameter CPI is set to FSCI (bits b8 to b5) in the 11th byte in the protocol information in ATQB shown in Figure 5. Also, when communication is started from the IDLE state, information indicating the maximum waiting time (FWT) among the elements included in the communication parameter CPI is set to FWI (bits b8 to b5) in the 12th byte in the protocol information in ATQB shown in Figure 5. In addition, when starting communication from the IDLE state, information indicating the guard time (SFGT) of the start frame, which is one of the elements included in the communication parameter CPI, is set in SFGI (bits b8 to b5) in the 13th byte of the protocol information in ATQB shown in Figure 5.

On the other hand, for example, when the IC chip 1 starts communication from a HALT state, information indicating the communication speed capability (BRC) (for example, "00000100") among the elements included in the communication parameters CPH is set to BRC (bits b8 to b1) in the 10th byte in the protocol information in ATQB shown in FIG. 5. Also, when communication is started from a HALT state, information indicating the maximum frame size (FSC) among the elements included in the communication parameters CPH is set to FSCI (bits b8 to b5) in the 11th byte in the protocol information in ATQB shown in FIG. 5. Also, when communication is started from a HALT state, information indicating the maximum waiting time (FWT) among the elements included in the communication parameters CPH is set to FWI (bits b8 to b5) in the 12th byte in the protocol information in ATQB shown in FIG. 5. In addition, when starting communications from a HALT state, information indicating the guard time (SFGT) of the start frame, which is one of the elements included in the communications parameters CPH, is set in SFGI (bits b8 to b5) in the 13th byte of the protocol information in ATQB shown in Figure 5.

As described above, the CPU 15 of the IC chip 1 transmits information indicating the communication parameter CPI to the external device 2 by a response signal when starting communication from the IDLE state, and transmits information indicating the communication parameter CPH to the external device 2 by a response signal when starting communication from the HALT state. Here, with reference to FIG. 6 and FIG. 7, the cases of starting communication from the IDLE state and starting communication from the HALT state will be described in relation to the state transition of the IC chip 1. FIG. 6 is a diagram showing the state transition of the IC chip 1 that employs Type A as the communication method. FIG. 7 is a diagram showing the state transition of the IC chip 1 that employs Type B as the communication method. Note that the specific conditions for the state transition of the IC chip 1 are publicly known from ISO/IEC14443-3, so a description thereof will be omitted.

First, in Type A, as shown in Fig. 6, when the IC chip 1 is outside the operating magnetic field emitted by the external device 2, it is in the POWER-OFF state and is not supplied with power, but when it enters the operating magnetic field, power is supplied and it transitions to the IDLE state. In the IDLE state, when the IC chip 1 normally receives a REQA (Request Command Type A) or a WUPA (Wake Up command Type A) from the external device 2 (i.e., when starting communication from the IDLE state), as described above, it transmits an ATQA including information indicating the size of the UID of the IC chip 1, which is one of the elements included in the communication parameter CPI, to the external device 2, and transitions to the READY state. In the READY state, when the UID of the IC chip 1 is selected by the external device 2, the IC chip 1 transitions to the ACTIVE state. In the ACTIVE state, when the IC chip 1 receives a RATS (Request for Answer To Select) from the external device 2 (which also corresponds to the case where communication is started from the IDLE state via the ACTIVE state), as described above, it transmits an ATS to the external device 2, which includes information indicating the maximum frame size (FSC), communication speed (DS), communication speed (DR), etc., among the elements included in the communication parameters CPI, and transitions to the PROTOCOL state.

On the other hand, in the ACTIVE state, when the IC chip 1 normally receives an HLTA (HaLT command, Type A) from the external device 2, it transitions to the HALT state. In this HALT state, only WUPA can be received. In the HALT state, when the IC chip 1 normally receives a WUPA from the external device 2 (i.e., when starting communication from the HALT state), as described above, it transmits an ATQA including information indicating the size of the UID of the IC chip 1 among the elements included in the communication parameter CPH to the external device 2, and transitions to the READY ^* state. In the READY ^* state, when the UID of the IC chip 1 is selected by the external device 2, the IC chip 1 transitions to the ACTIVE ^* state. In the ACTIVE ^* state, when the IC chip 1 receives a RATS from the external device 2 (which also corresponds to the case where communication is started from the HALT state via the ACTIVE ^* state), as described above, it transmits an ATS to the external device 2 including information indicating the maximum frame size (FSC), communication speed (DS), communication speed (DR), etc., among the elements included in the communication parameters CPH, and transitions to the PROTOCOL state.

Next, in Type B, as shown in FIG. 7, when the IC chip 1 enters the operating magnetic field, it is supplied with power and transitions to the IDLE state, as in Type A. In the IDLE state, when the IC chip 1 normally receives REQB (Request Command Type B) or WUPB from the external device 2 (i.e., when starting communication from the IDLE state), as described above, it transmits ATQB, which includes information indicating the communication speed capability (BRC) and maximum frame size (FSC) among the elements included in the communication parameter CPI, to the external device 2, and transitions to the READY-REQUESTED state or the READY-DECLARED state. In the READY-DECLARED state, when the IC chip 1 normally receives ATTRIB (PICC selection command, Type B) from the external device 2, it transitions to the PROTOCOL state. On the other hand, in the READY-DECLARED state, when the IC chip 1 normally receives HLTB (HaLT command, Type B) from the external device 2, it transitions to the HALT state. In the HALT state, only WUPB can be received. In the HALT state, when the IC chip 1 successfully receives a WUPB from the external device 2 (i.e., when starting communication from the HALT state), as described above, it sends an ATQB to the external device 2, which includes information indicating the communication speed capability (BRC) and maximum frame size (FSC) among the elements included in the communication parameters CPH, and transitions to the READY-REQUESTED state or the READY-DECLARED state.

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2. Operation of IC chip 1
Next, the operation of the IC chip 1 will be described with reference to FIG. 8. FIG. 8 is a flow chart showing an example of a communication parameter transmission process executed by the CPU 15 of the IC chip 1. The process shown in FIG. 8 is started when a command (REQA, WUPA, REQB, or WUPB) is received from the external device 2 while the IC chip 1 is in the IDLE state or HALT state. When the process shown in FIG. 8 is started, the CPU 15 judges whether the current state of the IC chip 1 is the IDLE state or the HALT state (step S1). If it is judged that the current state of the IC chip 1 is the IDLE state (step S1: IDLE state), the process proceeds to step S2. On the other hand, if it is judged that the current state of the IC chip 1 is the HALT state (step S1: HALT state), the process proceeds to step S6.

In step S2, the CPU 15 searches for the communication parameter CPI corresponding to the IDLE state. For example, the presence or absence of a file that manages information indicating the communication parameter CPI is searched for. Next, the CPU 15 determines whether the communication parameter CPI corresponding to the IDLE state has been set (i.e., whether it is stored in the NVM 13) based on the search result of step S2 (step S3). If it is determined that the communication parameter CPI corresponding to the IDLE state has been set (step S3: YES), for example, if a file that manages information indicating the communication parameter CPI is found, the process proceeds to step S4. On the other hand, if it is determined that the communication parameter CPI corresponding to the IDLE state has not been set (step S3: NO), the process proceeds to step S5.

In step S4, the CPU 15 reads information indicating the communication parameter CPI from the NVM 13, sets this in the response signal described above (adjusting the data format as necessary), and proceeds to step S9. In contrast, in step S5, the CPU 15 reads information indicating the default communication parameter CPD from the NVM 13, sets this in the response signal described above, and proceeds to step S9.

On the other hand, in step S6, the CPU 15 searches for the communication parameters CPH corresponding to the HALT state. For example, the CPU 15 searches for the presence or absence of a file that manages information indicating the communication parameters CPH. Next, the CPU 15 determines whether the communication parameters CPH corresponding to the HALT state have been set (i.e., whether they are stored in the NVM 13) based on the search results of step S6 (step S7). If it is determined that the communication parameters CPH corresponding to the HALT state have been set (step S7: YES), for example, if a file that manages information indicating the communication parameters CPH is found, the process proceeds to step S8. On the other hand, if it is determined that the communication parameters CPH corresponding to the HALT state have not been set (step S7: NO), the process proceeds to step S5.

In step S8, the CPU 15 reads information indicating the communication parameters CPH from the NVM 13, sets this in the response signal described above (adjusting the data format as necessary), and proceeds to step S9. In step S9, the CPU 15 transmits the response signal in which the information indicating the communication parameters was set in step S4, S5, or S8 to the external device 2 via the I/O circuit 11 and antenna, and ends the process. The process shown in Figure 8 described above can be generally applied to existing IC chips 1 in order to implement the present invention.

As described above, according to the above embodiment, the IC chip 1 is configured to transmit information indicating the communication parameter CPI to the external device 2 by a response signal when starting communication from the IDLE state, and to transmit information indicating the communication parameter CPH to the external device 2 by a response signal when starting communication from the HALT state, so that two types of communication parameters corresponding to two types of waiting states, the IDLE state and the HALT state, can be presented to the external device 2. Therefore, the external device 2 can switch between the two types of communication parameters presented at different times and the more suitable communication parameter for the external device 2 to communicate with the IC chip 1, so that communication performance can be improved. Furthermore, according to the above embodiment, the IC chip 1 is configured to transmit information indicating the IDLE state to the external device 2 by including it in the information indicating the communication parameter CPI when starting communication from the IDLE state, and to transmit information indicating the HALT state to the external device 2 by including it in the information indicating the communication parameter CPH when starting communication from the HALT state, so that the external device 2 can immediately recognize the current state of the IC chip 1 when receiving a response signal from the IC chip 1, and can switch communication parameters more quickly.

In the above embodiment, the IC chip 1 and the external device 2 perform non-contact communication. However, the present invention is also applicable to the IC chip 1 and the external device 2 perform contact communication. In this case, the IC chip 1 stores information indicating the first communication parameters when contact communication is started from a state (an example of a first standby state) waiting to receive a cold reset (i.e., a reset executed immediately after the IC chip 1 is activated) and information indicating the second communication parameters when contact communication is started from a state (an example of a second standby state) waiting to receive a warm reset (i.e., a reset executed when the voltage and clock are stable). Then, the IC chip 1 transmits information indicating the first communication parameters to the external device 2 when it receives the cold reset from a state waiting to receive a cold reset and starts contact communication, and transmits information indicating the second communication parameters to the external device 2 when it receives the warm reset from a state waiting to receive a warm reset and starts contact communication.

1 IC chip 11 I/O circuit 11a Power supply circuit 11b Clock generation circuit 11c Modulation/demodulation circuit 12 RAM
13 NVM
14 ROM
15 CPU

Claims (11)

An electronic information storage medium capable of communicating with an external device,
a storage means for storing information indicating a first communication parameter when starting communication from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when starting communication from a second standby state in which communication with the external device is waited for, the second standby state being different from the first standby state;
a transmitting means for transmitting information indicating the first communication parameter to the external device when starting the communication from the first standby state, and transmitting information indicating the second communication parameter to the external device when starting the communication from the second standby state;
An electronic information storage medium comprising: The electronic information storage medium according to claim 1, characterized in that the information indicating the communication parameters includes information indicating at least one of the maximum frame size, maximum latency, and communication speed. The electronic information storage medium according to claim 1, characterized in that the information indicating the first communication parameters includes information indicating the first standby state, and the information indicating the second communication parameters includes information indicating the second standby state. The electronic information storage medium according to any one of claims 1 to 3, characterized in that the communication is non-contact communication, the first standby state is an IDLE state, and the second standby state is a HALT state. An IC chip capable of communicating with an external device,
a storage means for storing information indicating a first communication parameter when starting communication from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when starting communication from a second standby state in which communication with the external device is waited for, the second standby state being different from the first standby state;
a transmitting means for transmitting information indicating the first communication parameter to the external device when starting the communication from the first standby state, and transmitting information indicating the second communication parameter to the external device when starting the communication from the second standby state;
An IC chip comprising: An IC card capable of communicating with an external device,
a storage means for storing information indicating a first communication parameter when starting communication from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when starting communication from a second standby state in which communication with the external device is waited for, the second standby state being different from the first standby state;
a transmitting means for transmitting information indicating the first communication parameter to the external device when starting the communication from the first standby state, and transmitting information indicating the second communication parameter to the external device when starting the communication from the second standby state;
An IC card comprising: A communication parameter transmission method executed by an electronic information storage medium capable of communicating with an external device, comprising:
storing information indicating a first communication parameter when starting communication from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when starting communication from a second standby state in which communication with the external device is waited for, the second standby state being different from the first standby state;
transmitting information indicating the first communication parameter to the external device when starting the communication from the first standby state, and transmitting information indicating the second communication parameter to the external device when starting the communication from the second standby state;
A communication parameter transmission method comprising: A computer included in an electronic information storage medium capable of communicating with an external device,
storing information indicating a first communication parameter when starting communication from a first standby state in which communication with the external device is waited for, and information indicating a second communication parameter when starting communication from a second standby state in which communication with the external device is waited for, the second standby state being different from the first standby state;
transmitting information indicating the first communication parameter to the external device when starting the communication from the first standby state, and transmitting information indicating the second communication parameter to the external device when starting the communication from the second standby state;
A program characterized by executing the above. An electronic information storage medium capable of communicating with an external device, the electronic information storage medium including a memory for storing at least information indicating default communication parameters used in communication with the external device,
a first determination means for determining whether a current state of the electronic information storage medium is a first standby state in which the electronic information storage medium waits for communication with the external device, or a second standby state in which the electronic information storage medium waits for communication with the external device and is different from the first standby state;
a second determination means for determining whether or not information indicating a first communication parameter for starting the communication from the first standby state is stored in the memory when it is determined that the current state is the first standby state, and for determining whether or not information indicating a second communication parameter for starting the communication from the second standby state is stored in the memory when it is determined that the current state is the second standby state;
a first transmission means for transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the first communication parameters is not stored in the memory, and for transmitting information indicating the first communication parameters to the external device when it is determined that the information indicating the first communication parameters is stored in the memory;
a second transmission means for transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the second communication parameters is not stored in the memory, and for transmitting information indicating the second communication parameters to the external device when it is determined that the information indicating the second communication parameters is stored in the memory;
13. An electronic information storage medium comprising: 1. A communication parameter transmission method executed by an electronic information storage medium capable of communicating with an external device, the electronic information storage medium having a memory for storing at least information indicating default communication parameters used in communication with the external device, the method comprising:
determining whether a current state of the electronic information storage medium is a first standby state waiting for communication with the external device, or a second standby state waiting for communication with the external device, the second standby state being different from the first standby state;
determining whether or not information indicating a first communication parameter for starting the communication from the first standby state is stored in the memory when it is determined that the current state is the first standby state, and determining whether or not information indicating a second communication parameter for starting the communication from the second standby state is stored in the memory when it is determined that the current state is the second standby state;
transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the first communication parameters is not stored in the memory, and transmitting information indicating the first communication parameters to the external device when it is determined that the information indicating the first communication parameters is stored in the memory;
transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the second communication parameters is not stored in the memory, and transmitting information indicating the second communication parameters to the external device when it is determined that the information indicating the second communication parameters is stored in the memory;
A communication parameter transmission method comprising: A computer included in an electronic information storage medium capable of communicating with an external device, the electronic information storage medium having a memory for storing at least information indicating default communication parameters used in communication with the external device,
determining whether a current state of the electronic information storage medium is a first standby state waiting for communication with the external device, or a second standby state waiting for communication with the external device, the second standby state being different from the first standby state;
determining whether or not information indicating a first communication parameter for starting the communication from the first standby state is stored in the memory when it is determined that the current state is the first standby state, and determining whether or not information indicating a second communication parameter for starting the communication from the second standby state is stored in the memory when it is determined that the current state is the second standby state;
transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the first communication parameters is not stored in the memory, and transmitting information indicating the first communication parameters to the external device when it is determined that the information indicating the first communication parameters is stored in the memory;
transmitting information indicating the default communication parameters to the external device when it is determined that the information indicating the second communication parameters is not stored in the memory, and transmitting information indicating the second communication parameters to the external device when it is determined that the information indicating the second communication parameters is stored in the memory;
A program characterized by executing the above.

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