Abstract:
The invention concerns a system for formatting a signal (s(t), (DMTin) in multicarrier modulation, which consists in clipping (18) the signal, in amplitude, with respect to a threshold value (Aclip), and in re-injecting (10), with delay and on a signal to be formatted, a clipping noise (clip) redistributed (19), at least partially, outside the used frequency band (f1-f2) of the multicarrier modulation signal.
Abstract:
A modular arithmetic coprocessor for performing calculations according to the Montgomery method, and comprising a division circuit for performing integer divisions. The integer division circuit calculates the division of binary data A coded over n' + n" bits by binary data B coded over n bits, with A, B, n, n' and n" being integers other than zero. For this functionality, the division circuit comprises first and second n-bit registers for containing binary data A and the division result, a third n-bit register for containing an intermediate result, a fourth n-bit register for containing binary data B, two subtracting circuits each having first and second serial inputs and a serial output, and a test circuit having an input and an output.
Abstract:
Integrated circuit memories, and specifically electrically programmable memories, are described. In order to take into account the fact that memory cells can comprise access contact flaws which may become fatal with age, a testing method is provided wherein the cells (TGF1) are read by comparing a reference cell (TGF) current Iref with the sum of the current I of the tested cell and a bias current I'bias which is weaker than current Ibias which is used in modes other than the testing mode (i.e. in normal memory reading mode).
Abstract:
A detection circuit which does not vary with the supply voltage is formed by measuring the voltage generated on the terminals of a diode (1) which is inversely polarized and which is fed by a constant current generator (2). Furthermore, said generator (2) is improved by a current consumption limitation circuit. Said circuit is particularly designed to be implanted, in CMOS technology, on the same substrate as a memory circuit or a microprocessor circuit.
Abstract:
A decision circuit (7) receives input addresses (I1 - I4) of instructions to be executed, and data addresses (D1 - D4) to which said instructions have to be applied. The decision circuit enables (8) the execution of the instruction or disables the execution of said instruction if it is to lead to a false operation or to a fraudulent attempt of divulgation of the system contents. A buffer register (9) stores the instruction addresses and subsequently presents them to the decision circuit simultaneously with the data addresses. This device applies more particularly to the protection of electronic integrated circuit memory cards.
Abstract:
Apparatus for depacketizing and aligning packetized input data. Data processing means (305) receives the input data via an input memory (301) and detects, identifies and determines payload size of a data packet of the input data. The data processing means (305) generates a payload size signal indicative of the size of the payload. A word formatter (303) receives units of the payload from the input memory (301) and gathers and aligns these to form data words. A payload counter (306) controls flow of input data from the input memory (301) to the word formatter (303) in accordance with the payload size signal. An input buffer (304) receives the data words from the word formatter (303), stores these and transfers them to the data processing means (305) for effecting data processing.
Abstract:
A power supply circuit with a storage capacitor is disclosed. The circuit includes a storage capacitor (C1) connected across the terminals of a rectifier bridge (1) and combined with a charging path and a discharging path. The charging path includes a predetermined-value current limiter (10, 10') controllable according to the voltage across the terminals of the rectifier bridge and the voltage across the terminals of the storage capacitor, whereby the storage capacitor is charged with a substantially constant current during each of the charging phases thereof.
Abstract:
A power factor correction circuit (3) has a first rectifier diode (D4) for controlling the serial charging of two capacitors (C1, C2), two rectifier diodes (D5, D6) for controlling the parallel discharging of the two capacitors, and a resistor (R) connected in series with the first diode (D4) in order to enhance the power factor and reduce the power-on current. An electronic current-controlled switch (T1) is used, and the parallel discharge diodes (D6, D5) are Zener diodes for protecting the load circuit against over-voltages just above the peak line voltage value.
Abstract:
Device for digitally carrying out a binary division according to a method of non recovery of partial remainders. The device mainly comprises a circuit for detecting null partial remainders (COND) during the division operation. Advantageously, the combinatory circuits (3, 5) are provided for calculating a correction bit (CS2) to correct the quotient using a single command. Finally a circuit (10) is advantageously provided to calculate at each division step, the bit of the complemented quotient for the following divion step, and a multiplexer (2) for introducing at the following step, the opposite of the complemented quotient bit on the less significant position of the quotient. The device of the invenion is applicable to signal processors.
Abstract:
Method and test platforms for the development of an integrated circuit (1) to be used in an application incorporating on the same chip: a signal processor (2), a RAM memory (4), a ROM memory (3) for receiving control software and processing software and specific input/output control peripherals of the application (5). The signal processor (2), the RAM memory (4) and the ROM memory (3) correspond respectively to existing discrete components. The processing software is developped and tested on a test platform including at least said discrete components by means of interface software that controls the platform and automatic test sequencing from a microcomputer.