FR3043820A1 - ELECTRONIC DEVICE COMPRISING A PLURALITY OF ELECTRONIC CHIPS, AND A READ TERMINAL SUITABLE FOR COOPERATING WITH SUCH A DEVICE - Google Patents

Abstract

The invention relates to an electronic device (C) adapted to cooperate with a reading terminal (T), comprising a plurality of chips (PC1-PC4), in which: - each chip (PC) is able to switch between a first mode in which it is able to communicate with the reading terminal bidirectionally and a second mode in which it can only receive a communication from the reading terminal; each chip (PC) is able to receive a selection command received from the reading terminal (T) to select a single chip (PC3) from among the chips of the device; said chips (PC) being configured so that, on receiving a selection command from one of the chips, the selected chip (PC3) switches in the first mode while each other chip (PC1, PC2, PC4) switches in the second mode.

Description

BACKGROUND OF THE INVENTION The invention relates to the field of communications between an electronic device, such as a smart card, and a reading terminal. The invention relates more particularly to the communication between a reading terminal and such a device comprising a plurality of separate electronic chips. The invention finds particular application in a smart card (or microcircuit card), conforming for example to the ISO 7816 standard, comprising a plurality of separate electronic chips, and also in a reader adapted to communicate with such a smart card. .

In general, a smart card is designed to communicate with a device external to this card, otherwise called reading terminal or reader. These cards make it possible to carry out various types of transactions, such as payment transactions, identification transactions and / or authentication of the bearer etc. Smart cards implementing one or more banking applications (credit card, debit card etc.) are for example able to communicate with payment terminals.

In the applications implemented today in smart cards, the exchange of information between the smart card and the reader can generally be done in two different ways: the contact communication and the so-called contactless communication. In the case of contact communication, the main protocols used define a communication between two - and only two - entities, namely a smart card reading device (a payment terminal for example) and a smart card. More specifically, these protocols are provided to allow communication between the reader (acting as "master"), on the one hand, and a single chip of the smart card (acting as "slave"), on the other hand.

The current communication protocols (ISO 7816 for example) do not allow several different chips of the same smart card to interact with a reader when reader and smart card cooperate together.

This constraint is now a major problem as modern smart cards are becoming more complex and can now integrate multiple chips to enrich the user experience or meet specific needs. Indeed, the implementation of different applications (banking, medical, loyalty ...) in the same card usually requires hardware resources that can not be supported on a single chip. For reasons of confidentiality and security, it is also better to combine several chips in the same smart card so as not to implement certain applications on the same chip.

It is for example known to integrate in a single bank card a first chip to implement a payment transaction according to the ISO 7816 standard with an external reader, and a second chip to control a display arranged in the card to display useful information to the user.

However, it becomes increasingly difficult to enrich the functionality of a smart card while ensuring that the current communication protocols are respected, especially in the particular case where several electronic chips - called "communicating" - d ' the same smart card is present to communicate with the outside. Here is meant by "communicating", a chip capable of communicating bidirectionally with the reader, that is to say, transmission and reception.

Indeed, within a single chip card, only one chip (acting as a slave) can communicate with a reader (acting as master) in accordance with current protocols, the other chips (also acting as slaves) being at most able to receive the incoming information in the smart card from the reader. In the absence of an acknowledgment message, the reader thus does not confirm that a non-communicating slave chip of the smart card has received - and therefore processes adequately - data intended for it.

One approach today is to repeat the sending of commands by the reader several times in order to increase the chances that these commands are well received and processed by the recipient slave chip in the smart card. It is sometimes also necessary to involve the user to ensure that a command is received (pressing a button, checking a display on the map ...).

It is therefore now necessary to optimize the communication between a reading terminal and a smart card (more generally an electronic device) comprising a plurality of separate electronic chips, so that said reading terminal can make sure that each chip receives and processes correctly the information of which it is intended, and this while respecting the current communication protocols (such as ISO 7816 for example).

Object and summary

One of the aims of the invention is to remedy the deficiencies of the state of the art described above. For this purpose, the present invention relates to an electronic device adapted to cooperate with a reading terminal, said device comprising a plurality of separate chips, in which: each chip is able to switch between a first mode of communication in which it is suitable communicating with the reading terminal bidirectionally and a second communication mode in which it can only receive a communication from the reading terminal; each chip is able to receive a selection command received from the reading terminal to select a single chip from among said chips of the device; said chips being configured so that, on receiving a selection command from one of said chips, the selected chip switches to the first mode while each other chip switches to the second mode.

The present invention makes it possible to optimize the communication between a reading terminal and a smart card (more generally an electronic device) comprising a plurality of separate electronic chips, so that said reading terminal can ensure that each chip receives and correctly processes information for which it is intended, while respecting the current communication protocols (such as ISO 7816 for example). The invention allows each chip of a smart card to dialogue in turn with a reading terminal. The selection made by the reading terminal gives the ability of a single chip of said card to send information to the reading terminal, all other chips being dumb so as not to interfere. The invention thus makes it possible to avoid any collisions that might occur if several chips of the same card attempt to communicate with the reading terminal at the same time (this situation is not generally well supported in the communication protocols). .

Advantageously, a reading terminal can in particular select a chip to which it is about to send a command so that the recipient chip can send back an acknowledgment message attesting the good reception of the command. The invention thus makes it possible to ascertain with certainty that information sent by the reading terminal has indeed been received by the recipient chip.

Thanks to the invention, it is possible to take better advantage of a plurality of electronic chips present in the same smart card, thus improving the user experience and the reliability of the communications.

According to a particular embodiment, the selection control comprises an identifier of the selected chip, each chip being able to determine from said identifier if it must switch in the first or the second mode.

According to a particular embodiment, said electronic device is a smart card.

According to a particular embodiment, said electronic device is an ISO 7816 chip card adapted to cooperate by contact with the reading terminal.

According to a particular embodiment, the selection command is of the APDU type.

According to a particular embodiment, upon reception of a signal RST (RESET) according to the ISO 7816 standard from the reading terminal, the chips are able to be configured according to a predetermined state so that, in said predetermined state, only one of said chips is in the first mode and each other chip is in the second mode.

According to a particular embodiment, one of said chips is a so-called main chip and each other chip among said chips is a so-called secondary chip, the main chip being configured to systematically respond with an ATR message to an RST command received from the terminal reading.

According to a particular embodiment, upon reception of said RST command sent by the reading terminal, each secondary chip is configured to switch in the second mode while the main chip is configured to switch in the first mode. In this example, the RST command (called "Cold Reset" in the ISO 7816 standard) is accompanied by a power failure of the card.

According to a particular embodiment, upon reception of said RST command sent by the reading terminal, the chips retain their state preceding the RST command. An RST command is for example launched when the card is powered. In ISO 7816, this state is called "Warm Reset".

Correlatively, the invention relates to a reading terminal adapted to cooperate with an electronic device comprising a plurality of separate chips, wherein: - each chip is able to switch between a first communication mode in which it is able to communicate with the terminal a bi-directional reading means and a second communication mode in which it can only receive a communication from the reading terminal; the read terminal is configured to send the electronic device a selection command for selecting a single chip from among said chips of the device so that the selected chip switches to the first mode while each other chip switches to the second mode.

According to a particular embodiment, the reading terminal is configured to generate the selection command to be sent to the electronic device.

According to a particular embodiment, said reading terminal is configured to include in the selection command an identifier of the selected chip, so that each chip can determine from said identifier if it must switch in the first or the second mode.

The selection command is for example an APDU type command.

The present invention also relates to a system comprising: an electronic device as defined above; and a reading terminal of said electronic device, as defined above.

The present invention also relates to a signal transmitted by a reading terminal cooperating with an electronic device comprising a plurality of separate chips, each chip of said electronic device being able to switch between a first communication mode in which it is able to communicate with the terminal. a bi-directional reading means and a second communication mode in which it can only receive a communication from the reading terminal; said signal comprising a selection command for selecting a single chip from said chips of said device so that the selected chip switches to the first mode while each other chip switches to the second mode. The invention also proposes a control method implemented by an electronic device capable of cooperating with a reading terminal, said device comprising a plurality of separate chips, in which: each chip is capable of switching between a first mode of communication in which it is able to communicate with the reading terminal bidirectionally and a second communication mode in which it can only receive a communication from the reading terminal; said method comprising the following steps: - receiving, by all the chips, a selection command from the reading terminal to select a single chip from among said chips; configuring said chips in response to said selection command so that: the selected chip switches to the first mode; and o each other unselected chip switches into the second mode.

According to a particular embodiment, the method comprises: - determining by each of said chips, from an identifier included in the selection command, whether said chip is selected or not by the selection command. The invention also proposes a control method implemented by a reading terminal adapted to cooperate with an electronic device comprising a plurality of separate chips, in which: each chip is able to switch between a first mode of communication in which it is able to communicate with the reading terminal bidirectionally and a second communication mode in which it can only receive a communication from the reading terminal; said method comprising: - sending a selection command to select a single chip from among said chips of the device so that the selected chip switches to the first mode while each other unselected chip switches to the second mode. Note that the various embodiments defined above in relation to the electronic device, on the one hand, and with the reading terminal, on the other hand, as well as the advantages associated with these entities, apply by analogy. the respective control methods defined above.

In a particular embodiment, the various steps of the control methods are determined by computer program instructions.

Accordingly, the invention also relates to a computer program on an information carrier (or recording medium), this program being capable of being implemented in an electronic device, in a reading terminal, or more generally in a computer, this program comprising instructions adapted to the implementation of the steps of at least one of the control methods as defined above.

This program can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other form desirable shape. The invention also provides a computer-readable information carrier (or recording medium), and including instructions of a computer program as mentioned above.

The information carrier may be any entity or device capable of storing the program. For example, the medium may comprise storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording medium, for example a floppy disk or a disk. hard. On the other hand, the information medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means. The program according to the invention can be downloaded in particular on an Internet type network.

Alternatively, the information carrier may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will emerge from the description given below, with reference to the accompanying drawings which illustrate embodiments having no limiting character. In the figures: FIG. 1 already described represents, in a schematic manner, a system comprising a smart card and a reading terminal, according to a particular embodiment of the invention; FIG. 2 schematically represents modules implemented in the read terminal of FIG. 1, in accordance with a particular embodiment of the invention; FIG. 3 diagrammatically represents the structure of one of the electronic chips included in the smart card illustrated in FIG. 1; FIG. 4 schematically represents modules implemented in the electronic chip illustrated in FIG. 3, in accordance with a particular embodiment of the invention; FIG. 5 represents, in the form of a flowchart, the main steps of control methods implemented respectively by a reading terminal and by a smart card, in accordance with a particular embodiment of the invention; FIGS. 6 and 7 schematically represent the configuration state of electronic chips of a smart card, according to particular embodiments; and - Figure 8 shows schematically the structure of a selection control, according to a particular embodiment.

Detailed description of several embodiments

As indicated above, the invention relates to communications between an electronic device and a reading terminal. The invention relates in particular to the communication between a reading terminal and such a device, when the latter comprises a plurality of separate electronic chips.

In the following exemplary embodiments, the electronic device is a smart card, this card being, for example, in accordance with the ISO 7816 standard. However, it will be understood that the invention is not limited to this particular implementation. Electronic devices other than a smart card can in particular be envisaged.

As explained above, the implementation of several separate chips in a smart card when the latter cooperates with a reading terminal poses certain difficulties. In this presentation are meant by separate chips, electronic chips each having their own communication interface for communicating with the outside of the smart card. The physical arrangement of these chips may vary depending on the case. In particular, separate chips can be mounted on the same substrate, see be embedded in the same component inside the smart card. The invention proposes to optimize the communication between a chip card equipped with a plurality of separate chips and a read terminal so that each chip of said card can, if necessary, communicate with the reading terminal. In the present description, and unless otherwise indicated, the term "communicate" means that a chip is capable of communicating bidirectionally (transmission and reception) with another entity, namely the reading terminal in the examples. that follow. The invention, according to its different embodiments, thus implements a chip card comprising a plurality of separate chips, each of them being able to switch between a so-called "communicating" mode in which it can communicate (bidirectionally ) with the reading terminal, and a so-called "listening" mode in which it can only receive a communication from the reading terminal. The reading terminal is able to select a single chip from those of the smart card so that only the selected chip operates in "communicating" mode, all the other unselected chips operating in "listening" mode. It is thus possible to avoid any collision between data transmitted at the same time by separate chips to the reading terminal.

Unless otherwise indicated, the elements common or similar to several figures bear the same reference signs and have identical or similar characteristics, so that these common elements are generally not described again for the sake of simplicity.

Figure 1 schematically shows the structure of a read terminal T (hereinafter referred to as "terminal") and an electronic device C here taking the form of a smart card, according to a particular embodiment. The terminal T and the smart card C are able to cooperate together to form a SY system.

In the example envisaged here, the smart card C and the terminal T are configured to cooperate together according to the ISO 7816 protocol.

In the rest of this presentation, it will be understood that certain elements generally present in a smart card, or in a reader of such a card, have been deliberately omitted because they are not necessary for the understanding of the present invention.

More specifically, the terminal T here comprises a processor 2, a non-volatile memory 4 and a connector 6.

The memory 4 is a rewritable non-volatile memory or a read only memory (ROM), this memory constituting a recording medium (or information medium) according to a particular embodiment, readable by the terminal T, and on which is recorded a computer program PG1 according to a particular embodiment. This computer program PG1 includes instructions for carrying out the steps of a control method according to a particular embodiment.

The connector 6 is configured to be detachably coupled with contacts 10 disposed on the card C, as explained below.

As represented in FIG. 2, the processor 2 controlled by the computer program PG1 here implements a command generation module 20 and a sending module 22. The command generation module 20 is able to generate commands ( APDU in this example) to the smart card C. As explained below, the command generation module is particularly able to generate selection commands. The sending module 22 is also able to send each command generated to the card C when it cooperates by contact with the terminal T.

As illustrated in FIG. 1, the smart card C comprises contacts 10, an AD module, and a plurality of separate electronic chips, namely four separate chips PCI, PC2, PC3 and PC4 (collectively referred to as PC) in this example. The number of PC chips can naturally be adapted according to the use case, it being understood that the number of PC chips is at least 2 in the C card.

As already indicated, the contacts 10 are adapted to be able to be coupled with the connector 6 of the terminal T.

In this embodiment, an adaptation module AD interfaces between the contacts 10 of the smart card C and the electronic chips PC2, PC3 and PC4. This adaptation module AD is an optional element which, in this example, makes it possible to adapt the voltage delivered to each of the chips PC2, PC3 and PC4 from the voltage applied by the terminal T via the contacts 10.

The function and nature of each chip may also vary depending on the particular case. Each chip can be configured to implement at least one specific application (banking, authentication, loyalty etc.).

According to this embodiment, each of the electronic chips PC is able to switch between a first communication mode Ml (called "communicating mode" or bidirectional) and a second communication mode M2 (called "listening mode"). Each PC chip operating in communicating mode Ml is able to communicate with the terminal T bidirectionally. In other words, the PC chip concerned is able to receive data from the terminal T and send data to the terminal T. Moreover, each PC chip operating in listening mode M2 can only receive a communication from the terminal T In other words, in listening mode M2, the communication between the terminal T and the PC chip concerned is possible only from the terminal T to the PC chip in question.

Also, each PC chip is at least able to receive commands from the terminal T, whether the communication mode used is Ml or M2.

Figure 3 schematically shows the structure of the PCI chip. It will be assumed here that the other chips PC2, PC3 and PC4 each have a similar structure to the PCI chip and therefore will not be described in detail for the sake of simplicity.

More specifically, the PCI chip comprises a processor 30, a communication interface 32 and a non-volatile memory 34.

The chip PCI is able, from the communication interface 32, to communicate via the contacts 10 with the outside of the smart card C, more particularly with the terminal T in this example.

The memory 34 is a rewritable non-volatile memory or a read only memory (ROM), this memory constituting a recording medium (or information carrier) according to a particular embodiment, readable by the PCI chip, and on which is recorded a PG21 computer program according to a particular embodiment.

Similarly, the chips PC2, PC3 and PC4 each include in a memory (not shown) a computer program PG22, PG23 and PG24, respectively. The PG21-PG24 computer programs thus collectively comprise instructions for executing the steps of a control method of the smart card C according to a particular embodiment.

As represented in FIG. 4, the processor 30 controlled by the computer program PG21 here implements a processing module 40 and a configuration module 42. It will be assumed in the same manner that the processor of each other chip PC2-PC4 implements modules similar to those mentioned above for the PCI processor.

More specifically, the processing module 40 is able to process the commands of the terminal T. In the embodiment described here, the processing module 40 is in particular configured to receive and process selection commands that can be sent by the user. terminal T as explained below. Furthermore, the configuration module 42 is able to appropriately switch the PCI chip in the communicating mode Ml or in the listening mode M2.

According to this particular embodiment, each PC chip is configured so that, upon receiving a selection command sent by the terminal T to select a single PC chip in the card C, the selected chip PC switches to the communicating mode Ml while each other unselected PC chip switches to the listening mode M2.

A particular embodiment is now described with reference to FIGS. 5, 6 and 7. More specifically, the terminal T implements a control method by executing the computer program PG1. Similarly, the smart card C implements a control method by executing the computer programs PG21 to PG24 (collectively forming a computer program PG2).

It will be assumed in this embodiment that the reading terminal T is coupled with the smart card C.

It is further assumed that the smart card C is in an initial state illustrated in FIG. 6, in which: the PCI chip is in the communicating mode Ml so that it is able to receive (RX) data originating from the terminal T and sending (TX) data to the terminal (bidirectional communication mode); and the chips PC2, PC3 and PC4 are each in listening mode M2 so that each of them can only receive a communication terminal T (unidirectional mode from the terminal T to each PC chip concerned).

As indicated above, the terminal T and the smart card C communicate here according to the ISO 7816 protocol.

During a step A2, the terminal T sends an initialization message RST (RESET type). This RST message is received (B2) by all the PCI to PC4 chips.

The terminal T is the entity that initiates the interaction with the smart card C; the terminal T therefore acts as master in this transaction while each of the PC chips of the smart card C acts as a slave.

In the embodiment described here, the PCI chip defaults to the slave chip responding to the RST initialization message. As such, the PCI chip is considered as the main chip in the sense that it is in charge of sending the ATR response message to the terminal T. The other PC2-PC4 chips act as a secondary slave chip to the extent that, by default, they are in listening mode M2 and as such are not able to send an ATR in response to the RST message of the terminal T. It will be understood, however, that other implementations are possible within the framework of the invention.

Being the only PC chip in Ml communication mode, the PCI chip is the only one to respond to the RST by sending (B4) an ATR (Answer-to-Reset) message to the terminal T. The chips PC2 to PC4 remain silent (they send no message back to terminal T).

Once the ATR message has been received (A4), the terminal T sends the APDU command (s) necessary to carry out the transaction (or operation) desired with the smart card C.

In this particular example, it is assumed that the terminal T needs to communicate with the electronic chip PC3. The latter being at this stage in listening mode M2, it is not able to transmit to the terminal T.

To do this, the generation module 20 of the terminal T generates (A6) a selection command CMD1 for selecting the chip PC3 - and only the chip PC3 - among the PC chips of the smart card C. In a particular embodiment , this command CMD1 comprises an identifier ID3 of the selected chip PC3, this identifier being included by the generation module 20 during the generation A6.

The selection command CMD1 is for example an APDU type command. For example, it shows the structure represented in FIG. 8. This figure represents a selection command in the form of a frame comprising the following fields: CLA: the instruction class indicating the type of the command; - INS: the instruction code indicating the command code; - PI and P2: the instruction parameters of the command; - The: defines the number of bytes sent by the command; - Data: number of bytes; - The: The maximum number of bytes expected in the response.

In this particular implementation, the field P2 comprises for example the identifier (or index) ID3 designating the chip PC3 as the selected slave chip.

According to a particular example, the field P2 comprises a code identifying the chip PC3 as a chip to be selected.

The terminal T sends (A8) then, with the aid of its sending module 22, the selection command CMD1 to the smart card C.

Each of the PCI, PC2, PC3 and PC4 chips receives (B8) in this example the CMD1 selection command. The processing module 40 of each PC chip analyzes (B10) then the selection command CMD1 and determines (B10), from this command (more particularly here using the identifier ID3), if the PC chip concerned is selected or not. In this example, each PC chip detecting that the identifier ID3 does not correspond to its own identifier deduces that it is not selected.

During the configuration step B12, the PC chips are configured so that: the selected PC chip (the chip PC3 in this example) by the command CMD1 switches (B12) in communicating mode Ml so as to be able to communicate bidirectional with the terminal T; all other unselected PC chips (PCI, PC2 and PC4 in this example) switch (B12) to listening mode M2 so that they can only receive commands from the terminal T.

Here, it is understood by "switching" the fact that a chip is configured in one of the communication modes M1 and M2 considered, it being understood that no change of mode is necessary if the chip was already in the mode appropriate to the moment of switching.

Figure 7 shows schematically the configuration of the PC chips once the B12 configuration performed.

During the sending step B14 (FIG. 5), the selected PC chip (PC3 in this example) sends a procedure byte (OP) byte, indicating that it has taken into account the selection command CMD1. This procedure byte OP can be, for example, an acknowledgment byte, a status word or an error code.

After reception (A14) of this procedure byte OP, the terminal T may, if necessary, send other complementary information in order to perform a given operation with the selected PC chip.

It will be noted that the terminal T may, if necessary, subsequently select another PC chip in order, in turn, to make the latter capable of responding to the commands of the terminal T. To do this, the terminal T sends (A16) another selection command (noted this time CMD2) to select the appropriate PC chip, as shown in Figure 5.

In a particular exemplary embodiment, the PC chips are configured in the predetermined initial state shown in FIG. 6 on receipt of a signal RST in accordance with the ISO 7816 standard sent by the terminal T. This predetermined state may be adapted as appropriate of use, it being understood that in this predetermined state, a single PC chip switches in the first mode Ml and each other PC chip switches in the second mode M2.

In the embodiment described with reference to FIG. 5, the reading terminal T is able to generate the selection command CMD1 sent to the sending step A8. However, it will be understood that it is not mandatory that it is the reading terminal T that generates the selection command within the meaning of the invention. According to a particular example, the reading terminal T receives this command for selecting an external device, for example from a banking system. The reading terminal T is then configured to transmit to the smart card C the selection command received from the outside.

In a particular example, the reading terminal T carries out a banking transaction in cooperation with the smart card C. A bank server for example sends at the end of the transaction a plurality of commands to the reading terminal T, in particular a selection command within the meaning of the invention. To do this, the reading terminal T must be connected to the bank server in question. In this particular example, the reading terminal T is not able to understand this selection command. The reading terminal T is configured to transmit this selection command to the smart card C. The generation of the selection command is therefore not performed by the reading terminal T in this particular case.

The present invention can find different applications.

According to a particular application, the present invention is used during the personalization of the smart card C. More specifically, during a customization of the card C, the reading terminal T is for example configured to send signals to various chips electronic devices present in the smart card. The reading terminal sends select commands to select each chip with which a dialog is needed. Once selected, each chip concerned can respond appropriately to the reading terminal, which allows the latter to ensure that data sent during the personalization process have been received by the recipient chip. In this particular application, the invention makes it possible to significantly improve the personalization of a smart card.

According to a particular application, the present invention is used during use of the smart card by a user. In a particular example, the smart card C comprises a display controlled by a specific chip (noted here PC2 for example) of the card C. The display is able, under the control of the chip PC2, to display information useful to the user. 'user. The reading terminal T is for example configured to send a display command to the chip PC2 of the card C in order to control the display on the display of data, such as an account balance or any other information (banking ...) appropriate. In this particular example, the reading terminal is able to send a selection command in order to select the PC2 chip controlling the display to ensure that said PC2 chip has taken into account a read terminal display command. .

In a particular example, the smart card C comprises a biometric sensor controlled by a specific chip (noted here PC3 for example) of the card C. The sensor is able, under the control of the chip PC3, to collect biometric information from the card. 'user. The reading terminal T is for example configured to send a data recovery command to the chip PC3 of the card C to control the activation of the biometric sensor. This data can then be used by the PCI chip to authenticate the carrier of the smart card. The invention makes it possible to optimize the communication between a reading terminal and a smart card (more generally an electronic device) comprising a plurality of separate electronic chips, while respecting the current communication protocols (such as ISO 7816 for example). . The invention allows each chip of a smart card to dialogue in turn with a reading terminal. The selection made by the reading terminal gives the ability of a single chip of said card to send information to the reading terminal, all other chips being dumb so as not to interfere. The invention thus makes it possible to avoid any collisions that might occur if several chips of the same card attempt to communicate with the reading terminal at the same time (this situation is not generally well supported in the communication protocols). .

Advantageously, a reading terminal can in particular select a chip to which it is about to send a command so that the recipient chip can send back an acknowledgment message attesting the good reception of the command. The invention thus makes it possible to ascertain with certainty that information sent by the reading terminal has indeed been received by the recipient chip.

Thanks to the invention, it is possible to take better advantage of a plurality of electronic chips present in the same smart card, thus improving the user experience and the reliability of the communications.

Those skilled in the art will understand that the embodiments and variants described above are only non-limiting examples of implementation of the invention. In particular, those skilled in the art may consider any adaptation or combination of the embodiments and variants described above to meet a particular need.

According to one embodiment, the invention is implemented by means of software and / or hardware components. With this in mind, the term "module" used in this presentation can correspond as well to a software component, a hardware component or a set of hardware and software components.

Claims (18)

1. Electronic device (C) adapted to cooperate with a reading terminal (T), said device comprising a plurality of separate chips (PC1-PC4), characterized in that: - each chip (PC) is able to switch between a first communication mode (Ml) in which it is able to communicate with the reading terminal bidirectionally and a second communication mode (M2) in which it can only receive a communication from the reading terminal; each chip (PC) is able to receive a selection command (CMD1) received from the reading terminal (T) to select a single chip (PC3) from among said chips of the device; said chips (PC) being configured so that, on receiving a selection command (CMD1) from one of said chips, the selected chip (PC3) switches in the first mode (Ml) while each other chip ( PCI, PC2, PC4) switches to the second mode (M2). 2. An electronic device according to claim 1, the selection control (CMD1) comprising an identifier (ID3) of the selected chip (PC3), each chip (PC) being able to determine from said identifier if it must switch in the first one. or the second mode. An electronic device according to claim 1 or 2, said electronic device (C) being a smart card. 4. An electronic device according to claim 3, said electronic device being an ISO 7816 chip card (C) capable of cooperating by contact with the CD-read terminal. An electronic device according to claim 4, wherein the selection control (CMD1) is of the APDU type. 6. An electronic device according to claim 4, wherein, on receiving a signal RST according to ISO 7816 from the reading terminal (T), the chips (PC) are able to configure themselves according to a predetermined state of so that in said predetermined state, only one of said chips is in the first mode (M1) and each other chip (PC2-PC4) is in the second mode (M2). 7. An electronic device according to any one of claims 1 to 6, wherein one (PCI) among said chips (PC) is a so-called principal chip and each other chip (PC2-PC4) among said chips is a so-called chip secondary, the main chip being configured to systematically respond with an ATR message to an RST command received from the reading terminal. 8. The electronic device as claimed in claim 7, wherein, on receipt of said RST command sent by the read terminal (T), each secondary chip (PC2-PC4) is configured to switch in the second mode (M2) while the main chip is configured to switch in the first mode (Ml). 9. Reading terminal (T) adapted to cooperate with an electronic device (C) comprising a plurality of separate chips (PC), characterized in that: - each chip (PC) is able to switch between a first communication mode ( Ml) in which it is able to communicate with the reading terminal bidirectionally and a second communication mode (M2) in which it can only receive a communication from the reading terminal; the reading terminal is configured to send to the electronic device (C) a selection command (CMD1) for selecting a single chip (PC3) from among said chips of said device so that the selected chip (PC3) switches in the first mode ( Ml) while each other chip (PCI, PC2, PC4) switches to the second mode (M2). 10. Read terminal according to claim 9, wherein said read terminal is configured to generate the selection command (CMD1) to be sent to the electronic device (C). 11. Read terminal according to claim 9 or 10, wherein said reading terminal is configured to include in the selection command (CMD1) an identifier (ID3) of the selected chip, so that each chip (PC) can determine from said identifier if it is to switch in the first or second mode. 12. System comprising: - an electronic device (C) according to any one of claims 1 to 8; and - a reading terminal (T) of said electronic device according to any one of claims 9 to 11. 13. Signal transmitted by a reading terminal (T) cooperating with an electronic device (C) comprising a plurality of separate chips (PC1-PC4), each chip (PC) of said electronic device being able to switch between a first communication mode (Ml) in which it is able to communicate with the reading terminal bidirectionally and a second communication mode (M2) in which it can only receive a communication from the reading terminal; said signal comprising a selection command (CMD1) for selecting a single chip (PC3) from among said chips of said device so that the selected chip (PC3) switches in the first mode (M1) while each other chip (PCI, PC2, PC4) switches to the second mode (M2). 14. Control method implemented by an electronic device (C) adapted to cooperate with a reading terminal (T), said device comprising a plurality of separate chips (PC1-PC4), characterized in that: - each chip ( PC) is able to switch between a first communication mode (Ml) in which it is able to communicate with the reading terminal bidirectionally and a second communication mode (M2) in which it can only receive a communication from the reading terminal; said method comprising the steps of: - receiving (B8), by all the chips (PC), a selection command (CMD1) from the reading terminal (T) to select a single chip (PC3) from among said chips; configuring said chips (PC) in response to said selection command so that: the selected chip (PC3) switches to the first mode (M1); and o each other unselected chip (PCI, PC2, PC4) switches to the second mode. 15. Control method according to claim 14, comprising: - determination (B10) by each of said chips, from an identifier (ID3) included in the selection command (CMD3), if said chip (PC) is selected or not by the selection command. 16. Control method implemented by a reading terminal (T) adapted to cooperate with an electronic device (C) comprising a plurality of separate chips (PC1-PC4), characterized in that: - each chip (PC) is capable of switching between a first communication mode (Ml) in which it is able to communicate with the reading terminal bidirectionally and a second communication mode (M2) in which it can only receive a communication from the reading terminal ; said method comprising: - sending (A8) a selection command (CMD1) to select a single chip (PC3) from among said chips of the device so that the selected chip (PC3) switches to the first mode (M1) while each other unselected chip (PCI, PC2, PC4) switches to the second mode. A computer program (PG1, PG21-PG24) comprising instructions for executing the steps of a method according to any one of claims 14 to 16 when said program is executed by a computer. 18. Recording medium (4; 34) readable by a computer on which is recorded a computer program (PG1; PG21-P24) comprising instructions for executing the steps of a method according to any of the Claims 14 to 16.