Abstract:
A method of calibrating an oscillator in order to compensate the dispersions generated, on the one hand, during the process of fabricating the oscillator circuit components and, on the other hand, by variations of operating conditions by modifying the parameters of a resonant component, for example a capacitor or an induction coil of the oscillator, in order to change the frequency range covered by the oscillator, according to the control voltage. Accordingly, calibrating the oscillator adjusts the output frequency of the oscillator according to an oscillator control signal. The calibration device determines the difference between the output frequency of the oscillator divided by a quantity and a reference frequency of the oscillator. The device includes a set of impedances selectively connected to the oscillator and each corresponding to a frequency deviation of the oscillator, and a calibration stage to generate a calibration word according to the measured frequency difference.
Abstract:
A coupled Lamb wave resonator filter includes first and second Lamb wave resonators. The first Lamb wave resonator includes a first resonant layer, and first and second electrodes on opposite sides of the first resonant layer. The second Lamb wave resonator includes a second resonant layer, and third and fourth electrodes on opposite sides of the second resonant layer. One of the sides of the first resonant layer belongs to a plane parallel to a plane corresponding to one of the sides of the second resonant layer. Both planes pass through the third and fourth electrodes of the second Lamb wave resonator. A periodic lattice acoustically couples the first and second resonant layers.
Abstract:
A method secures a memory in which individually read-accessible binary words are saved. The method includes defining a memory zone covering a plurality of words, calculating a cumulative signature according to all of the words in the memory zone, and storing the cumulative signature as an expected signature of the memory zone to check the integrity of data read in the memory. The method can be applied to the securing of smart cards.
Abstract:
A memory includes a plurality of memory cells each including a true data input connected to a true bit line and complementary data input connected to a complementary bit line, and two inverters connected head-to-tail firstly to the true data input and secondly to the complementary data input. The memory also includes a test circuit includes a plurality of test cells, each test cell includes a true data input connected to a complementary data input of the preceding test cell and a complementary data input connected to the true data input of the following test cell, the complementary data input of the last test cell being connected to the true data input of the first test cell, each test cell comprising a first inverter connected between the true data input and the complementary data input. The looped chain thus formed propagates a signal whose period is a function of the performance of the storage cells.
Abstract:
An input stage of an integrated circuit, includes a comparator for comparing the voltage of an input signal of the input stage with a reference voltage, and supplying a binary output signal the value of which depends on the result of the comparison of the input signal with the reference voltage. The input stage comprises a feedback circuit measuring a parameter representative of the operation of the comparator, and raising the reference voltage while the measured parameter reveals a faulty operation of the comparator.
Abstract:
A method and a circuit for limiting the current in an inductance, comprising means for interrupting the power storage in the inductance at the end of a delay triggered by the current in the inductance.
Abstract:
A persistent volatile memory cell memorizes a binary datum during a retention time independent from a supply voltage of the memory cell. The memory cell comprises a capacitive memory point supplying a persistent voltage and having a determined discharge time, a switch for triggering the discharge of the memory point when an erase signal has an active value, a switch for triggering the charge of the memory point when a write signal has an active value, and a sense-amplifier circuit having an input receiving the persistent voltage, and an output supplying the binary datum. The memory cell can be applied to the management of an inventory flag in a contactless integrated circuit.
Abstract:
An electronic circuit includes configurable cells with a test input and an output. The configurable cells are capable of being connected to one another in a chain in a predefined order via the test inputs and the outputs to form a test shift register if they receive a chaining command signal. A connection control module disconnects the test input from at least one configurable cell if the connection control module receives an invalid identification key. The connection control module leaves disconnected the test input from the at least one configurable cell, or applies a constant potential on the test input of the at least one configurable cell, or connects the test input of the at least one configurable cell at an output of a random-data generator.
Abstract:
A method for initializing a control device of a memory, the control device executing commands for accessing the memory transmitted to the memory by a control signal, the method comprising steps of detecting the switching on of the memory and of at least partially initializing the control device following the switching on of the memory. According to one embodiment of the present invention, the method comprises steps of detecting a specific event in the control signal, and of at least partially initializing the control device following the detection of the specific event.
Abstract:
The integrated circuit may include at least one electronic protection circuit for protecting against at least one electrostatic discharge and being able to discharge the overvoltage current generated by the electrostatic discharge. The electronic protection circuit includes a controlled short-circuiting switch embodied in CMOS technology including a CMOS technology TRIAC or a CMOS technology thyristor arranged in anti-parallel with a CMOS technology diode, and a triggering circuit for controlling the short-circuiting switch.