Abstract: The apparatus for sampling data recurring with a period (R) in the data signal (TS) includes a phasing circuit (43) that adjusts the delay of a clock signal with respect to one edge of the data signal to a value (n+.alpha.) R, where n is a positive integer or 0, and .alpha. is a positive number less than 1. The invention applies in particular to digital data transmission network systems, and in particular to information processing systems.

Abstract: The apparatus 15 for serialization of words of N bits SYNC, OP, D0-D7 produces N clock signals CL0-CL9 of period T, delayed successively by T/N, to control respective registers (36, 38, 39) for the successive output of the bits of each word. An adder (40) reunites these bits in a serial data transmission signal (TS). The deserialization is applicable in particular to network transmission systems, and especially to information processing systems.

Abstract: In certain bidirectional transmissions, differential links (L, L*) are used and transceivers (1) that furnish differential measurement signals (V, V*) representative of the transmission signals of the remote station are used. To reduce power consumption, the electrical power to the transceivers (1) may be interrupted during periods of inactivity. The method of the present invention consists in determining a threshold value which is intermediate in value between the maximum and minimum values that can be assumed by the measurement signals (V, V*), and furnishing a signal (VAL) representative of transmission activity resulting from the comparison between the measurement signals (V, V*) and the threshold value. The circuit for employing the method uses voltage comparators and may be an integrated circuit.

Abstract: The invention relates to tests for verifying the integrity of circuits (16) for serial bi-directional transmissions. These tests are capable of testing transceivers (12) operating a very high frequency without creating interference and consist in either leaving the serial output of the transceiver (12) disconnected from the line (L), or disconnecting (INF) its adaptation impedance, commanding the transmission of signals, and comparing the signals transmitted to the reception signals detected by the same transceiver. In a variant, the adaptation impedance of the transceiver of the remote station may be disconnected.

Abstract: The invention relates to an integrated circuit including impedances having precise values. To compensate for process variations and drift in impedances, the circuit includes automatic control means (3) to adjust the value of impedances (R) to a value that is a function of that of a reference impedance (Rc) external to the integrated circuit.

Abstract: Transceiver for transmission over serial bi-directional links having a bi-directional amplifier including an impedance (R) for adaptation to the line and connected to it, a generator (G1) commanded for transmission and supplying the adaptation impedance (R) and the line in parallel, detection device (G2, r) for furnishing a measurement signal (V) representative of either the current circulating in the adaptation impedance (R) when the generator (G1) is active, or the sum of the current in the adaptation impedance (R) and a compensation value when the first generator (G1) is not active. The compensation value is determined so as to make the measurement signal (V) independent of the transmission state of the transceiver.

Abstract: The variable delay device 10 includes an ECL gate 11 associated with an adjusting circuit 23 acting on the resistance of resistive load elements 14, 15 of transistors 12, 13 and the resistive load element 18 of the current source 16 at the gate 11 to cause the current produced by the source 16 to vary linearly while keeping the voltage at the collectors of the transistors 12, 13 constant. The range of variation of the resistances is selected in such a way that the delay between the input signals IN, IN* and OUT, OUT* varies substantially linearly. The invention is particularly applicable to systems for digital data transmission at a very high rate, of more than 1 gigabit per second.

Abstract: A variable delay circuit including a fixed delay circuit (D1) furnishing a signal (e.sub.1) that is delayed with respect to the input signal (e.sub.0). A combination circuit (C) furnishes a combination signal (f.sub.K) resulting from the superposition, with weighting and an integral effect of the input (e.sub.0) and delayed (e.sub.1) signals. The assembly is dimensioned such that the fixed delay (T) is less than the transition time that the combination signal (f.sub.K) has when only the input signal (e.sub.0) is applied.

Abstract: The digital data transmission is of the type including the addition of clock and synchronizing information to the data to constitute the transmission signal, and the determination of the transmission speed from this received information. According to the invention, this information, in the transmission signal, comprises a synchronizing edge (SYNC) added to each group of N data bits (D0-D7, OP), and the determination of the transmission speed comprises producing N clock signals (CL0-CL9) from identical successive delays (480-489) of a synchronizing edge detected.

Abstract: A dichotomizing, high speed analog - digital comprises an input stage for the voltage - current conversion of the analog signal, a reference current source, a sequence of N-1 identical cells in series, each comprising a comparator and current dividers, a terminal cell incorporating a comparator, a digital coder receiving a digital signal from each cell and, optionally, a link positioned between the consecutive cells. The analog signal is processed in the cells entirely in current form, the link means making it possible to isolate the potentials between successive cells.