Communication within an electronic device

The integration of a voltage level converter and selector in an embedded secure element addresses voltage level management challenges, enabling efficient and compact communication within electronic devices.

FR3159281A1Pending Publication Date: 2025-08-15STMICROELECTRONICS INT NV
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Patent Information

Application Number
FR2024001418
Authority / Receiving Office
FR · FR
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-02-14
Publication Date
2025-08-15

AI Technical Summary

Technical Problem

Complex electronic systems and devices face challenges in managing and adapting voltage levels across different circuits and modules, leading to inefficiencies and a need for more compact designs.

Method used

Integration of an embedded secure element with a voltage level converter and selector within the electronic device to adapt voltage levels for SIM cards, allowing bidirectional conversion and compact design.

Benefits of technology

Enables efficient voltage level management and compact design by directly integrating a selector and converter, facilitating seamless communication between SIM cards and embedded SIM cards.

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Abstract

Communication within an electronic device The present description relates to an embedded secure element (105) comprising: - at least one input (1052) adapted to receive at least a first data signal; - a circuit (1051) adapted to implement an embedded SIM card; - at least one output (1053) adapted to provide a second signal; - a first voltage level converter (1055) adapted to provide said second signal to said output; and - a selector (1054) adapted to receive said first signal and to provide it either to said circuit (1051) or to said output (1053) according to a command. Figure for the abstract: Fig. 1
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Description

Title of the invention: Communication within an electronic device Technical field

[0001] The present description relates generally to electronic systems and devices, and to the supply of power and the transmission of signals within these electronic systems and devices. The present description relates more particularly to the adaptation of voltage levels within a complex electronic system or device. Prior art

[0002] Complex electronic systems and devices may be composed of several circuits, modules, or subsystems, using different voltage levels. The use of voltage level adaptation circuits is therefore necessary for the proper functioning of this type of electronic system or device.

[0003] It would be desirable to be able to improve, at least in part, certain aspects of the management of voltage levels within an electronic system or device. Summary of the invention

[0004] There is a need for electronic systems and devices having better management of the voltage levels used by the circuits and modules that compose them.

[0005] There is a need for more compact electronic systems and devices.

[0006] One embodiment overcomes all or part of the drawbacks of known management of different voltage levels within an electronic system or device.

[0007] One embodiment provides an electronic system or device comprising an embedded secure element itself comprising a level converter circuit intended to adapt the voltage levels of signals intended for a SIM card.

[0008] One embodiment provides an on-board secure element comprising: - at least one input adapted to receive at least a first data signal; - a circuit suitable for implementing an on-board SIM card; - at least one output suitable for providing a second signal; - a first voltage level converter adapted to supply said second signal to said output; and - a selector adapted to receive said first signal and to supply it either to said circuit or to said output depending on a command.

[0009] According to one embodiment, said output is adapted to provide said second signal to a first location intended for a first SIM card.

[0010] According to one embodiment, said first voltage level converter is bidirectional.

[0011] According to one embodiment, said first voltage level converter comprises: - an input node; - an output node; - a first branch, connecting said input node to said output node, comprising a first delay circuit and a first voltage level booster circuit; and - a second branch, connecting the output node to said input node, comprising a second delay circuit and a second voltage level booster circuit.

[0012] Another embodiment provides a chip comprising an embedded secure element described above.

[0013] According to one embodiment, the chip further comprises a near field communication controller.

[0014] Another embodiment provides an electronic device comprising a chip described above, a router and said first location.

[0015] According to one embodiment, the device further comprises a second slot intended for a second SIM card.

[0016] According to one embodiment, the device further comprises a second voltage level converter connecting said router and said second location.

[0017] According to one embodiment, the device is a mobile telephone.

[0018] Another embodiment provides a method of communicating within the device described above between said router and said first location.

[0019] According to one embodiment, the method comprises the following successive steps: - sending a command to said selector indicating that said first location is selected; - sending, via said router, said first voltage to the input of said on-board secure element; - converting said first voltage, by said first voltage level converter, into said second voltage; and - sending, by said on-board secure element, said second voltage to said first location. Brief description of the drawings

[0020] These characteristics and advantages, as well as others, will be explained in detail in the following description of particular embodiments given without limitation in relation to the attached figures among which:

[0021] [Fig.l] represents, very schematically and in the form of blocks, an embodiment of an electronic device;

[0022] [Fig.2] shows in more detail the embodiment of [Fig.l];

[0023] [Fig.3] represents a level converter circuit according to one embodiment; And

[0024] [Fig.4] represents timing diagrams illustrating the operation of the circuit of [Fig.3]. Description of the embodiments

[0025] The same elements have been designated by the same references in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same references and may have identical structural, dimensional and material properties.

[0026] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been shown and are detailed.

[0027] Unless otherwise specified, when referring to two elements connected to each other, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") to each other, this means that these two elements can be connected or be connected by means of one or more other elements.

[0028] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "upper", "lower", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made unless otherwise specified to the orientation of the figures.

[0029] Unless otherwise specified, the expressions "about", "approximately", "substantially", and "of the order of" mean to within 10%, preferably to within 5%.

[0030] The embodiments described below relate to complex electronic systems and devices, and more particularly to the transmission of signals within such electronic systems and devices. The embodiments relate more particularly to the use of one or more SIM (subscriber identity / identification module) cards and one or more SIM cards embedded in such electronic systems or devices. A SIM card is an electronic device, generally a chip equipped with at least one microprocessor and a data storage means, carrying the identity of a user. An embedded SIM card, or eSIM card, is a software means carrying the identity of a user; it may be implemented by a circuit comprising, for example, a processor and a data storage means.

[0031] There are electronic systems or devices capable of implementing several SIM cards and / or embedded SIM cards. SIM cards and embedded SIM cards are not all suitable for receiving signals referenced at the same voltage levels. The embodiments described below propose to provide a compact electronic device in which the SIM cards and embedded SIM cards receive signals having suitable voltage levels.

[0032] Furthermore, the embodiments described below are particularly suitable for electronic systems and devices using SIM cards and embedded SIM cards, such as mobile phones or smart mobile phones, connected tablets, or any other connected objects that can use a SIM card.

[0033] [Fig.l] represents, schematically and in block form, an embodiment of an electronic device 100.

[0034] According to one example, the electronic device 100 comprises a processor 101 (App Method), such as for example a processor adapted to implement application functions.

[0035] The device 100 further comprises a router 102 (Modem) adapted to transmit signals within the device 100. According to one example, the router 102 can exchange signals with the processor 101. According to one embodiment, the router 102 comprises at least two terminals 1021 (ISO1) and 1022 (ISO2). The data signals provided by the router 102 are all referenced to a first voltage level Vddl.

[0036] The device 100 further comprises a chip 103 adapted to communicate with the processor 101 and / or the router 102.

[0037] The chip 103 optionally comprises a circuit adapted to implement a communication 104 (NFC). According to a preferred example, the circuit 104 is adapted to implement a near field communication (Near Field Communication), also called NFC, the circuit 104 is, in this case, also called NFC controller 104.

[0038] According to one embodiment, the chip 103 comprises an embedded secure element (eSE) 105 adapted to implement secure operations. The element 105 generally comprises its own processor(s), its own memory(s), and / or its own circuit(s) implementing various functions. In the embodiment described here, the embedded secure element 104 comprises at least one circuit 1051 (eSIM) adapted to implement an embedded SIM card. As previously stated, the circuit 1051 may comprise a processor and a data storage means.

[0039] The embedded secure element 105 further comprises at least two communication terminals 1052 (ISO2) and 1053 (ISO2), a selector 1054 and a voltage level converter 1055 (LS) whose uses are described below. The selector 1054 comprises an input connected, preferably connected, to the terminal 1052, a terminal control circuit, not shown in [Fig.l], and at least two outputs, one being connected to circuit 1051 and the other being connected to an input of voltage level converter 1055. An output of converter 1055 is connected, preferably connected, to terminal 1053.

[0040] According to one embodiment, the electronic device 100 comprises one or more slots intended to receive SIM cards. In particular, in [Fig.l], the device 100 comprises two slots 106 (SIM1) and 107 (SIM2). The slot 106 is connected to the terminal 1021 of the router 102. According to one embodiment, the slot 107 is connected to the terminal 1053 of the secure element 105.

[0041] The operation of the device 100 is as follows. As described previously, the device 100 is adapted to implement two SIM cards and one embedded SIM card. The router 102, however, only comprises two outputs allowing it to transmit data to these SIM cards and embedded SIM. During the use of the device 100 it is therefore necessary to make a choice on which SIM card and / or embedded SIM are used. A SIM card inserted in the slot 106 is always used since it is connected directly to the router. A SIM card inserted in the slot 107 is not always used since it is not connected directly to the router 102. The user of the device 100 therefore has the choice between using an embedded SIM card implemented by the circuit 1051 or a SIM card inserted in the slot 107.

[0042] When the user chooses to use an embedded SIM card. A method of communication between the router 102 and the circuit 1051 is as follows. A command is sent to the selector 1054 to indicate that the circuit 1051 is selected. This step can be carried out upstream of the implementation of a communication. When the router 102 has a data signal to transmit to the circuit 1051, it transmits it using its terminal 1022, the connection between the terminal 1022 and the terminal 1052, then the terminal 1052. The data signal is then transmitted by the selector 1054 to the circuit 1051. According to one embodiment, the circuit 1051 is adapted to receive data signals referenced to the first voltage level Vddl.

[0043] When the user chooses to use a SIM card placed in the slot 107. A method of communication between the router 102 and the slot 107 is as follows. A command is sent to the selector 1054 to indicate that the slot 107 is selected. This step can be carried out upstream of the implementation of a communication. When the router 102 has a data signal to transmit to the slot 107, it transmits it using the secure element 105, i.e. the terminal 1022, the connection between the terminal 1022 and the terminal 1052, then the terminal 1052. The data signal is then transmitted by the selector 1054 to the voltage level converter 1055 which converts it into a data signal referenced to a second voltage level Vdd2, different from the first voltage level Vddl. According to one embodiment, the slot 107, and a SIM card inserted therein are adapted to receive data signals referenced to the second voltage level Vdd2. The new data signal is then transmitted using the terminal 1053 and the connection between the terminal 1053 and the slot.

[0044] According to one example, the connections between terminals 1022, 1021, 1052, 1053 and locations 106 and 107 are connections using communication protocols according to the ISO7816 standard.

[0045] According to one example, the device 100 could further comprise a voltage level converter disposed between the terminal 1021 of the router 102 and the location 106. This converter would make it possible to convert the voltage levels of a signal provided by the router 102 for the location 107.

[0046] An advantage of this embodiment is that directly integrating into the secure element 105 a selector and a converter of the type of selector 1054 and converter 1055 makes it possible to make the device 100 more compact.

[0047] [Fig. 2] shows in more detail an embodiment of an electronic device 200 of the type of the electronic device 100 described in relation to [Fig. 1].

[0048] Like the device 100, the electronic device 200 comprises: - a router 201 (Modem) of the type of router 101 of [Fig.l]; - a chip comprising an embedded secure element 202 (eSE), of the type of the embedded secure element 105, and an NFC controller 203 (NFC) of the type of the NFC controller 104 of [Fig.l]; - two slots 204 (SIM1) and 205 (SIM2) intended to receive SIM cards, of the type of slots 106 and 107 of [Fig.l]; and - a voltage level converter 206 (LS_SIM1) connecting the router 201 to the location 204.

[0049] The router 201 comprises two sets of communication terminals, each set of communication terminals being dedicated to providing signals to a SIM card or an embedded SIM card, and two power supply terminals VREG1 and VREG2. Each set of communication terminals comprises: - a power supply terminal VCC1, VCC2 providing a supply voltage for referencing the data signals; - an activation terminal EN1, EN2 providing an activation signal; - a reset terminal RST1, RST2 providing a reset signal; - a communication terminal IO1, IO2 providing a data communication signal; and - a clock terminal CLK1, CLK2 providing a clock signal.

[0050] The embedded secure element 202 comprises a circuit adapted to implement an embedded SIM card, not shown in [Fig.2], a selector, a voltage level converter LS_eSE and communication terminals.

[0051] The communication terminals of the secure element 202 are as follows: - a VCC_eSE power supply terminal connected, preferably connected, to the VCC2 power supply terminal of the router 101; - an activation terminal EN_eSE connected, preferably connected, to the activation terminal EN2 of the router 101; - a reset terminal RST_eSE connected, preferably connected, to the reset terminal RST2 of the router 101; - an IO_eSE communication terminal connected, preferably connected, to the IO2 communication terminal of the router 101; - a CLK_eSE clock terminal connected, preferably connected, to the CLK2 clock terminal of the router 101; - a clock terminal CLK_SIM2 adapted to provide a clock signal to location 205; - an IO_SIM2 communication terminal adapted to provide a data signal to location 205; and - a reset terminal RST_SIM2 adapted to provide a reset signal at location 205.

[0052] The selector of the secure element 202 comprises SW-eSE switches controlled by a DRIV-eSE control circuit receiving a command from a SYS_SW_CMD control circuit and powered by a PWR_SW power supply circuit (PMU). In the example of [Fig. 2], the SW_eSE switches are three (3) in number and each comprises an input connected, preferably, respectively, to the terminals RST_eSE, IO_eSE and CLK_eSE. The outputs of the SW-eSE switches are connected, preferably connected, to inputs of the voltage level converter LS_eSE.

[0053] As described above, the selector allows data signals received from the router 201 and intended for a SIM card or an embedded SIM card to be directed and transmitted to the SIM card or the embedded SIM card according to a command. In the case illustrated here, the control circuit SYS_SW_CMD may be a processor of the element 202.

[0054] According to one embodiment, the voltage level converter LS_eSE comprises as many inputs as the switch SW_eSE comprises outputs. Here the voltage level converter LS_eSE comprises three inputs and three outputs. Each output of the converter LS_eSE is connected, preferably connected, to one of the communication terminals CLK_SIM2, IO_SIM2 and RST_SIM2 of the secure element. 202. The LS_eSE converter further comprises two power supply terminals, one receiving the power supply voltage supplied by the power supply terminal VCC_eSE corresponding to a first voltage level, of the type of the first voltage level Vddl described in relation to [Fig.l], and the other receiving a second power supply voltage corresponding to a second voltage level, of the type of the second voltage level Vdd2 described in relation to [Fig.l]. It should be noted that the part of the LS_eSE converter converting the voltage level of the data signal transmitted by the IO_eSE terminal is bidirectional. A detailed example of the LS_eSE converter and its operation are described in relation to Figures 3 and 4.

[0055] As described previously, the voltage level converter LS_eSE makes it possible to convert the voltage levels of the data signals provided by the router 201 before transmitting them to the location 205.

[0056] The NFC controller 203 is used here to communicate with the locations 204 and 205, but also to convey the supply voltages provided by the terminals VREG1 and VREG2 of the router 201, or by the NFC controller 203 as described below. For this, the NFC controller 203 comprises two communication terminals SWP_SIM1 and SWP_SIM2 adapted to provide a communication signal to the locations 204 and 205.

[0057] To provide the supply voltages, the NFC controller 203 comprises two power receiving terminals VUICC_IN 1 and VUICC_IN2, two switches SW_1 and SW_2, two voltage regulators LDO1 (LDO) and LDO2 (LDO), and two power transmitting terminals V_SIM1 and V_SIM2. The terminal VUICC_IN1, respectively VUICC_IN2, is connected, preferably connected, to the terminal VREG1, respectively VREG2, of the router 201. The switch SW_1, respectively SW_2, comprises a first conduction terminal connected, preferably connected, to the terminal VUICC_IN1, respectively VUICC_IN2, and a second conduction terminal connected, preferably connected, to the terminal V_SIM1, respectively V_SIM2. An output of the voltage regulator LDO1, respectively LDO2, is connected, preferably connected, to the terminal V_SIM1, respectively V_SIM2.

[0058] Locations 204 and 205 each comprise five terminals including: - a VCC terminal suitable for receiving a supply voltage; - a CLK terminal adapted to receive a clock signal; - an IO terminal adapted to receive a data signal and to provide a data signal; - an RST terminal adapted to receive a reset signal; and - an SWP terminal adapted to receive a data signal and to provide a data signal.

[0059] According to one embodiment, the terminals of location 205 are connected in the following manner: - the VCC terminal is connected, preferably connected, to the V_SIM2 terminal of the NFC controller 203; - a CLK terminal is connected, preferably connected, to the CLK_SIM2 terminal of the embedded secure element 202; - an IO terminal is connected, preferably connected, to the IO_SIM2 terminal of the embedded secure element 202; - an RST terminal is connected, preferably connected, to the RST_SIM2 terminal of the embedded secure element 202; and - an SWP terminal is connected, preferably connected, to the SWP_SIM2 terminal of the NFC controller 203.

[0060] The voltage level converter 206 is used to adapt the voltage levels of the signals provided by the router 201 to the location 204. For this, the converter 206 comprises the following terminals: - an activation terminal EN connected, preferably connected, to terminal EN1 of the router 201; - an input clock terminal CLK1 connected, preferably connected, to the CLK1 terminal of the router 201; - an input communication terminal IO1 connected, preferably connected, to the terminal IO1 of the router 201; - an input reset terminal RST1 connected, preferably connected, to the RST1 terminal of the router 201; - an output clock terminal CLK-SIM1 connected, preferably connected, to the CLK terminal of location 204; - an output communication terminal IO_SIM1 connected, preferably connected, to the IO terminal of location 204; and - an output reset terminal RST_SIM1 connected, preferably connected, to the RST terminal of location 204.

[0061] The converter 206 comprises several voltage booster circuits connecting its input and output terminals.

[0062] According to one embodiment, the terminals of location 204 are connected in the following manner: - the VCC terminal is connected, preferably connected, to the V_SIM1 terminal of the NFC controller 203; - a CLK terminal is connected, preferably connected, to the CLK_SIM1 terminal of the voltage level converter 206; - a terminal 10 is connected, preferably connected, to the terminal IO_SIM1 of the voltage level converter 206; - an RST terminal is connected, preferably connected, to the RST_SIM1 terminal of the voltage level converter 206; and - an S WP terminal is connected, preferably connected, to the SWP_SIM1 terminal of the NFC controller 203.

[0063] The operation of the device 200 is identical to the operation of the device 100 described in relation to [Fig.l].

[0064] [Fig. 3] is an electrical diagram of a part of a voltage level converter 300 of the type of voltage level converter LS_eSE described in relation to [Fig. 2]. More particularly, [Fig. 3] illustrates the part of the converter 300 making it possible to convert the data signal supplied by the terminal IO_eSE into the data signal supplied by the terminal IO_SIM2 of the embedded secure element 202.

[0065] The converter 300 comprises two branches. A first branch makes it possible to convert the voltage level of a first data signal received on the IO_eSE terminal to provide a second data signal to the IO_SIM2 terminal. A second branch makes it possible to convert the voltage level of a third data signal received on the IO_SIM2 terminal to provide a fourth data signal to the IO_eSE terminal.

[0066] The first branch comprises a delay element D301 comprising a resistor R301 and a capacitor C301. A first terminal of the resistor R301 is connected, preferably connected, to a node A, itself connected to the terminal IO_eSE. A second terminal of the resistor R301 is connected, preferably connected, to a node B. A first terminal of the capacitor C301 is connected, preferably connected, to the node B, and a second terminal of the capacitor C301 is connected, preferably connected, to a node receiving the reference potential.

[0067] The first branch further comprises an AND301 logic gate and an OR301 logic gate. A first input of the AND301 gate is connected, preferably connected, to node A, and a second input of the AND301 gate is connected, preferably connected, to node B. An output of the AND301 gate is connected, preferably connected, to a first input of the OR301 gate. An output of the OR301 gate is connected, preferably connected, to a node C.

[0068] The first branch further comprises a voltage level booster circuit LS301, or voltage level booster LS301. The booster LS301 comprises an input DIS connected, preferably connected, to node C, and an input IN connected, preferably connected, to node A. A power supply terminal of the booster is connected, preferably connected, to the node receiving the voltage V_SIM2. An output of the booster LS301 is connected, preferably connected, to node D.

[0069] The second branch comprises a delay element D302 comprising a resistor R302 and a capacitor C302. A first terminal of the resistor R302 is connected, preferably connected, to node D. A second terminal of the resistor R302 is connected, preferably connected, to a node E. A first terminal of the capacitor C302 is connected, preferably connected, to node E, and a second terminal of the capacitor C302 is connected, preferably connected, to the node receiving the reference potential.

[0070] The second branch further comprises an AND302 logic gate of the "AND" type and an OR302 logic gate of the "OR" type. A first input of the AND302 gate is connected, preferably connected, to node D, and a second input of the AND302 gate is connected, preferably connected, to node E. An output of the AND302 gate is connected, preferably connected, to a first input of the OR302 gate. An output of the OR302 gate is connected, preferably connected, to a node F.

[0071] The second branch further comprises a voltage level booster circuit LS302, or voltage level booster LS302. According to one embodiment, the booster LS302 is identical to the LS301. The booster LS302 comprises an input DIS connected, preferably connected, to the node F, and an input IN connected, preferably connected, to the node D. A power supply terminal of the booster is connected, preferably connected, to the node receiving the voltage V_SIM2. An output of the booster LS302 is connected, preferably connected, to a node A.

[0072] The converter 300 further comprises two logic gates INV301 and INV302 of the inverting type (NOT). An input of the gate INV301 is connected, preferably connected, to the input DIS of the booster LS302, and an output of the gate INV301 is connected, preferably connected, to a second input of the gate OR301. An input of the gate INV302 is connected, preferably connected, to the input DIS of the booster LS301, and an output of the gate INV302 is connected, preferably connected, to a second input of the gate OR302.

[0073] The converter 300 further comprises a pull-up resistor R303 and a transistor T302 for setting the voltage level at the terminal IO_eSE. The resistor R303 comprises a first terminal connected, preferably connected, to the node A connected to the supply terminal VCC_eSE, and a second terminal connected, preferably connected, to the terminal IO_eSE. A first conduction terminal of the transistor T302 is connected, preferably connected, to the terminal IO_eSE, and a second conduction terminal of the transistor T302 is connected, preferably connected, to a node receiving a reference potential, for example ground. According to one example, a control terminal of the transistor T302 is left floating. According to one example, the transistor T302 is a metal-oxide gate field effect transistor (metal-oxide- semiconductor field-effect transistor), or MOSFET transistor, or MOS transistor. Additionally, transistor T302 is an N-channel MOS transistor, or N-type MOS transistor, or NMOS transistor.

[0074] The converter 300 further comprises a pull-up resistor R304 and a transistor T302 for setting the voltage level at the terminal IO_SIM2. The resistor R304 comprises a first terminal connected, preferably connected, to the node D connected to the supply terminal VCC_SIM2, and a second terminal connected, preferably connected, to the terminal IO_SIM2. A first conduction terminal of the transistor T302 is connected, preferably connected, to the terminal IO_SIM2, and a second conduction terminal of the transistor T302 is connected, preferably connected, to a node receiving a reference potential, for example ground. According to one example, a control terminal of the transistor T302 is left floating. According to one example, the transistor T302 is an NMOS transistor.

[0075] The operation of the voltage level converter 300 is described in relation to [Fig.4].

[0076] [Fig.4] includes timing diagrams illustrating the operation of the voltage level converter 300 described in relation to [Fig.3].

[0077] More particularly, [Fig.4] represents the temporal evolution of the following data signals: - an IO_eSE signal representing the evolution of the data signal present at the IO_eSE terminal; - a signal B representing the evolution of the data signal present at node B; - a signal E representing the evolution of the data signal present at node E; - a signal C representing the evolution of the data signal present at node C; - a signal F representing the evolution of the data signal present at node F; and - an IO_SIM2 signal representing the evolution of the data signal present at the IO_SIM2 terminal.

[0078] As soon as the signal IO_eSE has a falling edge, the signals E, C and IO_SIM2 all immediately have a falling edge and the signal F is not modified. The signal B also has a falling edge delayed by the delay element D301. However, when the signal IO_eSE has a rising edge, the signals B, E, C and IO_SIM2 all have a rising edge with a delay defined by the delay element D301, and the signal F is not modified.

[0079] Conversely, as soon as the signal IO_SIM2 has a falling edge, the signals B, E and IO_eSE all immediately have a falling edge and the signal C is not modified. The signal F also has a falling edge delayed by the delay element D301. However, when the signal I0_SIM2 has a rising edge, the signals B, E, F and IO_eSE all have a rising edge with a delay defined by the delay element D301, and the signal C is not modified.

[0080] An advantage of the voltage level converter 300 is that the presence of the delay elements D301 and D302 makes it possible to obtain a bidirectional converter, that is to say a converter capable of converting the voltage level of a signal arriving at the terminal IO_eSE and also of a signal arriving at the terminal IO_SIM2. Without the presence of the delay elements D301 and D302, no data would be transmitted.

[0081] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will occur to those skilled in the art.

[0082] Finally, the practical implementation of the embodiments and variants described is within the reach of those skilled in the art from the functional indications given above.

Claims

Claims

1. Embedded secure element (105; 202) comprising: - at least one input (1052; RST_eSE, IO_eSE, CLK_eSE) adapted to receive at least a first data signal; - a circuit (1051) adapted to implement an embedded SIM card; - at least one output (1053; RST_SIM2, IO_SIM2, CLK_SIM2) adapted to provide a second signal; - a first voltage level converter (1055; LS_eSE; 300) adapted to provide said second signal to said output; and - a selector (1054; SW_eSE) adapted to receive said first signal and to provide it either to said circuit (1051) or to said output (1053; RST_SIM2, IO_SIM2, CLK_SIM2) according to a command.

2. An element according to claim 1, wherein said output is adapted to provide said second signal to a first location (107; 205) for a first SIM card.

3. Element according to claim 1 or 2, wherein said first voltage level converter (1055; LS_eSE; 300) is bidirectional.

4. Element according to claim 3, wherein said first voltage level converter (1055; LS_eSE) comprises: - an input node (A, D); - an output node (D, A); - a first branch, connecting said input node (A, D) to said output node (D, A), comprising a first delay circuit (D301, D302) and a first voltage level booster circuit (LS301, LS302); and - a second branch, connecting the output node (D, A) to said input node (A, D), comprising a second delay circuit (D302, D301) and a second voltage level booster circuit (LS302, LS301).

5. Chip (103) comprising an embedded secure element (105; 202) according to any one of claims 1 to 4.

6. The chip of claim 5, further comprising a near field communication controller (104; 203).

7. An electronic device (100; 200) comprising a chip according to claim 5 or 6, a router (102; 201) and said first location (107; 205).

8. Device according to claim 7, further comprising a second slot (106; 204) for a second SIM card.

9. Device according to claim 8, further comprising a second voltage level converter (206) connecting said router and said second location (106; 204).

10. Device according to any one of claims 7 to 9, being a mobile telephone.

11. A method of communicating within the device according to any one of claims 7 to 10 between said router (102; 201) and said first location (107; 205) comprising at least one step of communicating between said first input and said selector.

12. Method according to claim 11, comprising the following successive steps: - sending a command to said selector (1054) indicating that said first location (107; 205) is selected; - sending, by said router (102; 201), said first voltage to the input of said on-board secure element (103; 202); - converting said first voltage, by said first voltage level converter (1055; LS_eSE; 300), into said second voltage; and - sending, by said on-board secure element (103; 202), said second voltage to said first location (107; 205).

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