FR2880713A1 - Chip card`s circuits communication paths switching method for e.g. mobile telephone, involves emitting communication paths switching control signal on electrical contact situated in inserted part of card and not on card`s connection button - Google Patents

Abstract

The method involves applying a supply voltage on a chip card (1) by electrical contacts disposed on a connection button (3) of the card. Communication paths switching control signal is emitted by a reader on an electrical contact situated in an inserted part of the card and not on the button. A communication path of a circuit of the card is switched in order to permit communication through the button. Independent claims are also included for the following: (A) a portable electronic device inserted in a chip card reader (B) a chip card reading apparatus.

Description

The present invention relates to a method for switching

  communication for chip card circuits, a chip card and a reader apparatus for carrying out the method.

  Many devices today contain a smart card reader. Smart cards are objects generally associated with an individual or a service and equipped with integrated circuits in particular for a security purpose. Smart cards are used in mobile telephony to identify a subscriber, in the banking field to certify payment and lo in television decoders to authenticate the rights of a subscriber. Among the current smart cards, the microprocessor cards contain a CPU, a ROM containing an executable program, a working RAM and an EEPROM for the permanent storage of data. The microprocessor cards are connected to the reader by means of contact pads, these pads allow the power supply, the reset signal (abbreviated reset), the clock signal to clock the microprocessor, and a communication line. bidirectional called I / O. Another plot called 1/02 is normalized and can be used for communication but it is not currently used. The position of all the pads, the nature of the transmitted electrical signals and the data exchanged by the I / O line are standardized in the ISO 7816-1, 2 and 3 standard, published by ISO. As a rule, five pins are used, only one of which can transport data bidirectionally.

  The plastic card must be flexible enough to be put in a pocket or wallet, and the circuit incorporated inside must withstand a certain level of curvature. For this, the size of the single circuit is limited to twenty square millimeters. As a result, performance is limited both in computing power and in memory. Nowadays, smart cards are more and more used and there is a real need to increase performance. An increase in performance can be achieved by increasing the number of circuits in the card. Such a solution has been adopted by several card manufacturers who have implemented up to four circuits, each close to one of the four corners of the card. An adapted serigraphy allows the user to know the applications implemented in each of the s circuits, in this way he can introduce the card into the reader, the circuit he wants to put under tension being that under the pad on the top at the end. to the right of the card when it comes to the reader's entrance. In this way, the user has only one card instead of four. This solution has the disadvantage that two circuits can not communicate at the same time with the reader. To go from one circuit to another, the user must remove the card and introduce it by changing direction and / or changing the face. The user must therefore be constantly present to perform these operations, and in any case, this solution is not possible if two circuits of the card must communicate with each other.

  Another way is to provide the card with a contact communication for a circuit and a contactless communication with another circuit. There are known chip card circuits that are connected to a coil embedded in the thickness of the card. The coil provides both power and communication. But the communication with one or the other circuit requires to equip the reader with a connector and coils, being careful that the signals exchanged by a communication channel does not pollute the signals exchanged with the other communication channel . As a result, this solution is expensive and difficult to implement.

  The object of the present invention is a method of switching communication channels allowing an electronic circuit card reader to communicate with several circuits of the card inserted in the reader, each circuit having a communication channel; characterized in that it comprises the steps of: - applying a supply voltage to the card by electrical contacts arranged on a connection button, - sending by the reader a control signal of the switching of the signal channels. communication on an electrical contact located in the inserted part of the card but not on the button, - switching a communication channel of a circuit allowing the latter to communicate via the connection button.

  In this way, the reader can select the circuit of the card introduced with whom he wants to communicate. The transmission of the switching signal on an electrical contact situated in the inserted part of the card but not on the button makes it possible not to use pads of the card whose use is standardized.

  According to a first improvement, the method comprises a step of detecting a signal on the electrical contact of the card indicating the presence of a switching unit. In this way, the reader recognizes whether the card introduced has one or more circuits and a switching means 1s for dialogue with each of them. According to another improvement, the control signal consists of a plurality of elementary signals whose number determines the switching position. In this way, the switching is done by counting these elementary signals.

  According to another improvement, the switching also applies to the communication control signals such as Clock and Reset. In this way, the reader can individually activate each circuit.

  The object of the invention is also a portable electronic device inserted in a chip card reader comprising an electrical connection button comprising pads for communication with a circuit of the device; characterized in that it comprises a switching circuit for establishing a communication path between at least one pad (I / O) of the button and one of a plurality of circuits arranged on the device, said switching circuit being controlled by a signal transmitted by an electrical contact that is not on the connection button.

  According to a first improvement, the device comprises means for transmitting a signal on the electrical contact indicating the presence of the switching circuit. In this way, the card can transmit the indication to the outside if it has or not a switching circuit. According to another improvement, the switching circuit comprises at least one second circuit for switching control signals such as Clock and Reset. In this way, the circuits present on the card can be activated individually.

  According to another improvement, the device comprises several slots for the introduction of smart card. The slots have connectors for communication with an inserted card. The I / O to pin of each connector being connected to a switching pad of the switching circuit. In this way, the device allows communication between a reader and several smart cards. According to one improvement, each of these housings comprises a switch for the detection of a card. A management circuit processing the signals from the switches and transmitting the processed information via a pad of the connection button.

  According to another improvement, the device comprises a means of introduction of commands and / or display, a position of the switch allowing communication between the pad (I / O) of the button and said insertion means and / or display. In this way, the device can serve as a communication interface with the user. According to another improvement, the position of the electrical contact characterizes categories of devices. In this way, couples of readers and cards cooperating only together can be defined.

  The object of the invention is also a chip card reader device comprising a housing having a connector provided with electrical contacts intended to cooperate with the pads of a connection button of a card inserted in said housing, and a switch for detecting the presence of a card inserted in the apparatus; characterized in that said switch has a metal part intended to come into contact with a card inserted into the housing, the apparatus further comprising means for transmitting a communication channel switching signal enabling the reader to communicating with a circuit of the card, the switching signal being transmitted by the decay presence switch.

  The invention, with its features and advantages, will emerge more clearly on reading the description of a particular nonlimiting exemplary embodiment made with reference to the appended drawings in which: FIG. 1 presents a block diagram of a reader showing the main connections with a smart card according to a preferred embodiment to embodiment, - Figure 2 schematically shows an embodiment of the card according to the invention, - Figure 3 shows a timing chart showing the evolution of the main signals exchanged during of the powering up of a card according ts an exemplary embodiment, - Figure 4 is a diagram of a card trundle, according to a variant of an exemplary embodiment.

  FIG. 1 is a block diagram of a reader 2 showing the main connections with a smart card 1. The reader 2 has a slot which gives access to a housing containing a set of connectors cooperating with the pads of the card when the one is introduced in abutment at the bottom of the housing.

  The smart card 1 has a connection button equipped with pads 25 standardized according to ISO 7816-3. We find: - GND and + Vcc: power supply (5 volts or 3 volts), - Reset: reset signal of the microprocessor, - Clock: clock signal to clock the microprocessor, - Vpp: voltage (21 to 25 Volts) for EPROM (unusual) caries, - I / O: bidirectional data transmission line, AUX1, AUX2: signals used for NDS type security cards.

  The connectors cooperating with the button being generally sliding contacts, and the pads being positioned in two rows, it would be destructive for the microprocessor that electrical signals are applied to the pads when the card is being inserted. A card presence switch 10 placed at the bottom of the housing detects when the card is fully inserted. The signal emitted by the switch 10 triggers the activation of the signals + Vcc, Clock, Reset according to a precise order, specified by the ISO 7816-3 standard. Following this, the microprocessor of the card is activated and sends the Reset Response on the I / O line. Other protocols can be envisaged, in particular for synchronous cards.

  In a particularly economical and widespread manner, the card presence switch 10 consists of two metal strips which, in the absence of cards are in electrical contact. When a card is completely inserted, its edge folds one of the slats which breaks the contact ts with the other slat. The lamella in contact with the card is electrically connected to a pull-up resistor connected to the + Vcc of the reader and to a shaping circuit for detecting the electrical levels for processing by the central unit of the card reader . The disappearance of a GND level (0 volts) is an indication of the presence of a card. The detected level indicates whether it is a card with or without electrical contact cooperating with the switch 10. As soon as the card is removed from the reader, the blade returns to contact the other blade which is connected to the GND, it is ie the electrical zero. In the absence of a card, the signal is 0 volts.

  Figure 2 shows a card 1 according to a preferred embodiment. The card is equipped with a button 3 comprising connection pads according to the ISO 7816 standard. A metal strip 4 of 2.5 mm is positioned on the edge of the card so as to come into contact with the card presence switch. background of housing a card reader. The card also includes several integrated circuits including microprocessors 6, called CP1, CP2, CP3 and CP4, and a four-position switch circuit called SWITCH. Each microprocessor 6 has an I / O line for unidirectional or bidirectional communication. The GND, + Vcc, RESET and Clock signals supply all the central units. The line I / O of the pad is connected to the switch COMMUT, as well as the different lines of communication I / Oi of the microprocessors 6 CP1, CP2, CP3 .... The switch has as much position as there are circuits 6 with which the reader can communicate. According to a preferred embodiment, the switching signal for selecting the I / Oi line communicating with the reader is provided by the additional contact 4 which is not on the ISO standard pad. The additional contact 4 is electrically connected to the control input o of the switch SWITCH.

  According to an improvement not shown in FIG. 2, the SWITCH switch has a triple switching circuit, which makes it possible to switch the Clock and Reset lines in addition to the I / O line. As a result, the clock and reset pins are no longer connected to the pads of the button 4 as before, but connected to the second and third terminals of the second and third circuits of the switch 5. In order to keep the electrical levels constant, all the electrical levels of the Clock and Reset pins of circuits 6 are held at 0 volts by a resistor. Thanks to this improvement, the reader can activate each circuit 6 separately.

  After having detailed the various elements, we will now describe how these cooperate with the aid of the chronogram of figure 4.

  The central unit of the reader continuously analyzes the electrical level present on the card presence switch 10. If the card has no electrical contact, the voltage detected on the card presence switch is + Vcc. The power of the card then takes place in a conventional manner. If the voltage detected on the card presence switch is an intermediate voltage, for example 2.5 volts, this means that there is an electric current passing through the pull-up resistor of the reader and a resistance implanted on the card. Then, the central unit of the reader applies the supply voltage + VCC on the board of the board 1. At this moment the commutator switch is powered, its default position at its power up is to connect 1/01 of the circuit CP1 with the I / O pad of the button. If the reader wishes to communicate with the circuit CP1, he does not need to send a switching signal. If the reader wishes to interact with another microprocessor then he sends on the card presence switch 10 a sequence formed of a determined number of pulses. At each pulse, the switch changes position, after two pulses I / O of the pad is connected to 1/02 of CP2, after three: 1/03 of CP3, etc. Through the use of a metal card presence switch, the transmission of a communication channel switching signal does not require any modification of the hardware characteristics of the reader.

  An alternative embodiment consists in applying a determined voltage to the card presence switch 10. The position of the switch depends directly on the value of the applied voltage. For example, if the voltage is between 1 and 2 volts, the switch electrically connects 1/01 CP1 circuit with the pad I / O button. If the voltage is between 2 and 3 volts, the switch electrically connects 1/02 CP2 circuit with the pad I / O button, between 3 and 4 volts, it is 1/03 CP3 circuit and between 4 and 5 volts, it's 1/04 of the CP4 circuit. This variant has the advantage that the application of a new voltage immediately changes the position of the switch.

  An improvement is that the card inserted into the reader is a trunk card having an interface with the user and several connectors for communication with multiple smart cards.

  An exemplary embodiment of the trunk card is shown schematically in FIG. 4. The trunk card which bears the same reference 1 as the card described in FIG. 3 consists of an epoxy plate having the same thickness as a card. microprocessor (0. 9 mm). The limit of the part inserted into the reader is represented by a dotted line. The button 3 supports the ISO 7816 standard connections. A metal strip 4 of 2.5 mm fixed on the edge of the card is applied to the card presence switch at the bottom of the card reader housing. The trunk card has a first part that is inserted into the reader and a second that remains accessible to the user. The boundary between the two parts is represented by a dotted line in Figure 3. This second part comprises a keyboard 7 comprising keys accessible to a user, a display 8 and three slots 9 stacked on each other to insert a maximum of three cards 11 microprocessor. The GND, + 'Vcc, RESET and Clock pads of the button 3 are electrically connected to the corresponding pins of the three connectors inside the three housings 9, so that these pads are electrically connected to the corresponding pads of the cards 11 introduced in the slots 9. The I / O line of button 3 is connected to the SWITCH switch 5, as are the I / O pins of the three connectors inside the three slots. The switch has four positions, the pad corresponding to the first position is connected to a management circuit of the keyboard 12, this circuit is advantageously a microcontroller. The three other pads are each connected to the I / O pin of each of the three connectors inside the three housings 9. The additional contact 4 is electrically connected to the control input of the switch SWUT so that the signal of switching emitted by the reader selects the I / Oi line of the circuit with which it wishes to communicate.

  Each housing has a card presence switch 13. A pad of the switch is connected to the GND, the other to a resistor connected to the + Vcc. In the absence of a card, the switch is closed and the voltage at its terminal is 0 volts. The appearance of a signal of a level + Vcc on the switch 13 means that a card is completely inserted in the housing 9. The three switches 13 are connected to the management circuit of the keyboard 12. In this way, the management circuit receives the information if cards are introduced into the housing and can provide it to the reader when it asks him.

  The trunk card can also support means of sound emissions such as a speaker and a buzzer. The keyboard management circuit 12 performing the management of the keyboard 7, the screen 8 and the presence of the cards 11 is located in a privileged way out of the insertion zone in the reader, where there is no thickness constraint. This does not exclude that it is in the insertion zone, respecting the maximum thickness of 0.9 mm. The connection wires between the button 3, the electrical element 4, the switch 5, the management circuit 12, and the connectors of the housings 5 are preferably made in the form of a copper deposit on the epoxy plate, the deposits are then covered with insulating element. The trunk card can also support a security module. A security module is a circuit of the same type as that of a microprocessor card, with additional security functions.

  A use of the gig card is that the reader performs a teleshopping application with the help of a pay-per-view network. A first housing contains the private access card to the broadcast network, this card contains the viewing rights of the audiovisual programs. A second home is intended to receive a bank card. It allows the payment of a selected object during a teleshopping program.

  As for the card described in FIG. 3, an improvement is that the switch SW has a triple switching circuit. In this way, the clock and reset pins of the connectors 9 are no longer connected to the corresponding pads of the button 4 as before, but electrically connected to the second and third circuits of the switch 5. In order to keep the electrical levels constant, all the electrical levels Clock and reset pins of the connectors installed in each housing 9 are held at the GND by a resistor. With this improvement, the reader can activate separately each card 11 inserted in each slot 9.

  According to another improvement, the position of the electrical edge of the card and the position of the card presence switch are arranged at a determined location. The rectilinear part of the width of a card being 48 mm, it is possible to have an electric edge every 3 mm, which makes 16 possible positions. In all rigor, to be able to perform the switch, it is necessary that the contact of the card is facing the metal part of the card presence switch. If they are not, no electrical contact is made, and the card will be treated conventionally. With the aid of this improvement, it is possible to define pairs of readers cooperating only with certain models of nesting cards.

  The present embodiments should be considered by way of illustration but may be modified in the field defined by the scope of the appended claims. In particular, other ways of detecting an electrical contact on a smart card are possible without departing from the scope of the present invention. In particular, the invention is not limited to television decoders but can be applied to any device to have a microprocessor card reader.

Claims (15)

claims   A method of switching communication channels enabling an electronic circuit card reader to communicate with several circuits of the card inserted in the reader, each circuit having a communication channel; characterized in that it comprises the steps of: - applying a supply voltage to the card by electrical contacts arranged on a connection button, - sending by the reader a control signal of the switching of the signal channels. communication on an electrical contact situated in the inserted part of the card but not on the button, - switching of a communication channel of a circuit allowing it to communicate via the connection button.   2. A method of switching communication channels according to claim 1; characterized in that it comprises a step of detecting is a signal on the electrical contact of the card indicating the presence of a switching unit.   3. A communication channel switching method according to claim 1 or 2; characterized in that the transmission of a control signal comprises a plurality of elementary signals whose number determines the switching position.   4. A method of switching communication channels according to any one of claims 1 to 3; characterized in that the switching signal also switches communication control signals such as Clock and Reset.   5. A portable electronic device (1) inserted in a chip card reader comprising an electrical connection button (3) comprising pads for communication with a circuit of the device (6; 11); characterized in that it comprises a switching circuit (5) for establishing a communication path between at least one pad (I / O) of the button (3) and a circuit (6; 11; 12) among a plurality of circuits arranged on the device, said switching circuit (5) being controlled by a signal transmitted by an electrical contact (4) which is not on the connection button (3).   Portable electronic device according to claim 5; characterized in that it comprises means for transmitting a signal on the electrical contact (4) indicating the presence of the switching circuit (5).   7. A portable electronic device according to claim 5 or 6 characterized in that the switching circuit (5) comprises at least a second circuit for switching control signals such as Clock and Reset.   8. Portable electronic device according to any one of claims 5 to 7; characterized in that the device comprises a plurality of slots (9) for the introduction of smart card, the slots being provided with connectors for communication with an inserted card, the I / O pin of each connector being connected to a pad switching circuit (5).   Portable electronic device according to claim 8; characterized in that each housing (9) comprises a switch (13) for card detection, the device comprises a presence management circuit.   10. Portable electronic device according to any one of claims 5 to 9; characterized in that the device comprises means for introducing commands (7) and / or for displaying (8), a position of the switch allowing communication between the pad (I / O) of the button (3) and said means introduction and / or display.   Portable electronic device according to any of claims 5 to 10; characterized in that the position of the electrical contact (4) characterizes categories of devices.   12. Device reader (2) of a smart card having a housing having a connector provided with electrical contacts intended to cooperate with the pads of a connection button of a card (1) inserted in said housing, and a switch (10) for detecting the presence of a card (1) inserted in the apparatus; characterized in that said switch (10) has a metal part intended to come into contact with a card inserted into the housing, the apparatus further comprising means for transmitting a communication channel switching signal enabling the reader to communicate with a circuit of the card, the switching signal being transmitted by the card presence switch (10).   Smart card reader device (2) according to claim 12; characterized in that it comprises means for detecting a signal on the electrical contact of the card indicating the presence of a switching unit on the card (1) introduced.   Smart card reader device (2) according to claim 12 or 13; characterized in that it comprises means for transmitting a plurality of elementary signals constituting the switching signal, the number of elementary signals defining the circuit of the card communicating with the device.   The smart card reader device (2) according to any one of claims 12 to 14; characterized in that the position of the card presence switch (10) defines categories of apparatus for cooperating with corresponding card categories.