Abstract:
A process and apparatus for sampling a serial digital signal (D), which includes phasing of the digital signal with a clock signal (C) and sampling the digital signal at delayed instants (Si), wherein the phasing is carried out in reference to the sampling instants. The phasing includes determining phasing test instants (Pi) which refer to the sampling instants (Si) to verify whether transitions of the digital signal are leading or lagging in phase relative to the phasing test instants. The determination of the phasing test instants is achieved by adding to each sampling instant (Si) a delay Y=kR/2, in which k is a positive whole odd number other than zero and R designates a pulse repetition period of the bits of the digital signal (D). The invention has particular utility in data processing and remote data processing systems, and to telecommunication systems.
Abstract:
A testing device for testing dynamic characteristics of an electronic circuit using serial transmissions. The circuit includes a multiplexing device and a demultiplexing device for implementing a serial link in the component or circuit. The testing device includes a transmitter for transmitting binary signals to the multiplexing device, a receiver for receiving binary signals from the demultiplexing device, and a link for selectively providing a coupling between the transmitter and the receiver. Additionally, a clock generator delivers a first clock signal to the transmitter and a second clock signal, which has a different frequency than the first clock signal, to the receiver. In one preferred embodiment, the clock generator includes a single programmable-frequency oscillator and a variable delay circuit. The programmable-frequency oscillator delivers the first clock signal and the variable delay circuit delays the first clock signal to deliver the second clock signal. The testing device can be used with circuits operating at frequencies in the range of 100 MHz. A method of testing dynamic characteristics of an electronic circuit using a testing device is also provided.
Abstract:
Disclosed is a device for the conversion of a series signal received in the form of a low-amplitude, high-frequency differential signal into n parallel signals. The device uses a scheme derived from that of a static memory cell as a sample-and-hold unit and amplifier. The device continues to perform well when the differential signal comprises noise in common mode.
Abstract:
An Exclusive-OR logic gate with four two-by-two complementary inputs and two complementary outputs. The structure of this Exclusive-Or gate is said to be symmetrical in that the gate has a propagation time that is identical whichever of the two pairs of complementary inputs is switched over, whatever the nature of the transition at output and whatever the logic state of the pair of inputs that do not switch over. The disclosed device enables a further reduction in the differences in the time taken for the propagation of the signal edges through the gate by eliminating the floating character of certain nodes. It also relates to a frequency multiplier comprising a tree of Exclusive-Or gates such as this.
Abstract:
An integrated circuit comprises at least one differential input stage. The differential input stage includes an input circuit and a shaping circuit. The input circuit comprises a first portion and a second portion for providing two pairs of differential signals. The propagation times of the first and second circuit portions are preferably substantially identical. The shaping circuit differentiates each of the two pairs of differential signals and combines them to obtain a single binary type of signal.
Abstract:
A circuit for receiving digital data arriving in series comprising a circuit for generating a reference dock and a circuit for oversampling the received data memorizing the samples sampled at the rate of several clocks phase-shifted with respect to the reference clock, the oversampling circuit comprising means for selecting and providing as output data samples representative of the received data and, further, a detection circuit identifying the variations of the phase shift between the reference clock edges and the transitions of the received data by analyzing the memorized samples, the detection circuit controlling a frequency variation of the reference dock when the phase shift variations repeat over several sampling cycles.
Abstract:
An integrated circuit (IC) includes a device (10) that adapts the impedance to the characteristic impedance (Zc) of transmission lines (13) each connecting a transmitter (11) to a receiver (12). Two adaptation blocks (14, 15) reproduce the respective structures of the transmitters (11) and receivers (12) and their impedance is adapted by a reference resistor (Rr). A closed loop control device (Len, Lep, Lrn, Lrp) reproduces the adaptation conditions in the transmitters (11) and receivers (12) respectively.
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.
Abstract:
A method for monitoring the execution of a program by a processor of an electronic circuit comprises operations of collecting monitoring data within the circuit and of transmitting the monitoring data to a device for debugging the program. The monitoring data are transmitted via a connection external to the circuit, comprising at least one serial connection. The monitoring data are serialized within the circuit before being transmitted, then restored within the device for tuning the program.