摘要:
One embodiment of the invention comprises a functional module for storing and exchanging data, comprising a common portable support, at least one passive contactless integrated circuit in the form of a first semi-conductor chip, a contactless integrated circuit reader in the form of a second semi-conductor chip, the contactless integrated circuit and the reader being gathered on or in the common portable support, an antenna coil of the contactless integrated circuit, connected to the contactless integrated circuit, an antenna coil of the reader, connected to the reader, the antenna coil of the contactless integrated circuit being coupled to the antenna coil of the reader.
摘要:
A contactless integrated circuit is provided that includes a RFID communication interface, a UHF communication interface, a data processing unit, an interface multiplexer, a communication mode detection circuit, a first modulation and demodulation circuit, a second modulation and demodulation circuit, and a multiplexer demultiplexer circuit. The interface multiplexer couples the data processing unit to the RFID or UHF communication interfaces. The multiplexer demultiplexer circuits are driven by mode signals delivered by the communication mode detection circuit, to link the data processing unit to one of the two modulation and demodulation circuits.
摘要:
A method for selecting an electronic module from a plurality of at least two modules (M1, M2, M3) capable of emitting messages simultaneously, includes the steps of sending a general query message (ACTIVALL) to the modules, and selecting (AFI, SELECT-ID) the module having responded first, the modules, on receiving a query message (ACTIVALL, ACTIV), determining a random time interval (P) and sending a responding message (ID, R) when the said time interval (P) has elapsed. A module is set in idle position (IDL) when it receives a message (MESS) before the time interval (P) preceding the sending of a response (ID, R) has elapsed. The idle position (IDL) is at least characterized by the fact that one module does not respond, subsequently, to a complementary query message (ACTIV). This invention is particularly useful for contactless smart card readers and for terminals for electronic labels.
摘要:
To resolve the problems related to the divulgation of the algorithms for the transcoding of the secret codes in chip cards, notably prepayment type chip cards, it is planned to limit the number of authentication operations possible by the number of units contained in the card. It is shown that in this case this number, which is generally small, for example about a hundred units, limits the number of attempts that can be made by a fraudulent person trying to penetrate the mysteries of the secret enciphering algorithm.
摘要:
The invention relates to chip cards. There is disclosed a chip card (12) with only two contacts intented both to information exchanges (instructions and data) between the card (12) and a card reader and to the power supply of the card (12). According to the invention, the contacts are preferably a clock contact (CLK) used to the synchronization of data and instructions, and a data input/output contact (I/O) used to the transmission of data and instructions from the reader to the card (12) and to the transmission of data from the card (12) to the reader. For the power supply, a full-wave rectifier (bridge of diodes) may be arranged between the two contacts (CLK;I/O). The invention also relates to the communication protocole which allows to use only two contacts (CLK;I/O) while having instructions similar to those of conventional chip cards (initialization of the card, address incrementation of memory cell, reading of the cell, writing, comparison of a confidential code).
摘要:
The disclosure relates to counters that require the counting to be done under conditions of high security. In such a counter, starting from a number represented by a certain number of bits, the stages of the counter are successively forced, one after the other, to represent the final number in an order such that at no instant do the contents of the counter represent a number smaller than the initial number. A particular structure is used to count very big numbers while, when the technology is of the EEPROM type. This prevents the stage that changes its state most frequently from being subjected to action more than is physically permitted by the technology used. The disclosed method makes it possible, in chip cards, to prevent the diminishing of memorized values representing substantial values which are, for example, monetary values.
摘要:
The use of charge pumps to supply bit lines, when programming memory cells connected to a bit line, is avoided by pre-charging this bit line simultaneously with the neutralization of the selection of this bit line. Subsequently, the pre-charging potential is uncoupled and the effects of the neutralization are stopped. It is known that this method of action prevents the breakdown of a single programming potential generator, used to supply all the bit lines. This results in a gain in space in the lay-out of the control circuits of the memory cells in the memory plane. This method can be implemented especially in page mode programming for memories where the memory cells have EEPROM-type floating-gate transistors.
摘要:
The melting of a fuse of a CMOS type integrated circuit is caused by using the existence of a stray thyristor created in the neighborhood of the boundaries of pads made in a substrate. This stray thyristor is triggered by artificially making the potential drop in an intermediate region of the pad. The thyristor always comes on suddenly, the current that flows through the thyristor is very high and the phenomenon stops spontaneously when the fuse is melted.
摘要:
The depassivation of an integrated circuit is detected by using the fact that the passivation coat which covers this circuit participates in the coupling capacitances that exist between parallel metallized lines made on its surface. The variation in one of these capacitances, resulting from depassivation, leads to a modification of the dielectrical induction of a voltage step, emitted on one line, in another line. The resulting variation in the induced voltage is used to produce a logic signal that reveals this depassivation. This logic signal can be used to neutralize the functioning of the integrating circuit to be protected.
摘要:
The invention is a dry surface skiing apparatus including a leading self-steering swivel caster and trailing non self-steering swivel caster. It offers major safety improvements compared to the existing prior art. Its operation closer resembles modern carving ski and eliminates problems such as swivel caster flutter and undesirable drift effect with rotary turns. It also adds the ability to brake. Elimination of flutter is achieved by application of non self-steering trailing swivel caster which is cross connected to the leading self-steering swivel casters by a steering system. The ground friction of the wheel in the trailing swivel caster dampens the flutter. At the same time since the rear wheel turns in the opposite way to the front wheel, a carved turn is achieved in a similar manner to flexing a carving ski along its entire length. In order to facilitate braking wing like members are attached to the outer edge of each ski which allow transmitting friction of ski pole tips to the ski platform.