Stmicroelectronics S.a.

Stmicroelectronics S.r.l.

Sgs-thomson Microelectronics S.a.

Sgs-thomas Microelectronics S.a.

St&eacute;phane Hanriat

Jean-Pierre Schoellkopf

Bertrand Borot

Christophe Frey

The present invention relates to a logic simulation method, in which a signal is switched between two logic states to simulate a transition of a real signal. The method comprises the step of inserting between the two logic states of the signal an intermediate state for a time interval indicative of the slope of the transition of the real signal.

Method of accurate simulation of logic circuits

The present invention relates to a method of functional testing of a logic circuit and to an integrated circuit for implementing the method. The method includes providing at least one test pattern and the storage of this test pattern in a first test register, this providing step being synchronized by an external clock signal; serially providing of this test pattern to an input of the internal logic circuit, this providing step being synchronized by a test clock signal generated from an internal clock signal; storing, in a second test register connected to the output of the internal logic circuit, at least one resulting pattern generated by the internal logic circuit when the test pattern is provided thereto, this storing being synchronized by the test clock signal; and providing to the outside, by series shifting, of the resulting pattern, this providing step being synchronized by the external clock signal.

Functional testing method and circuit including means for implementing said method

A ROM including memory cells, the programmed cells being formed of a transistor connected between a bit line and a supply potential, the cells being organized in sets of at least one column coupled to one sense amplifier per set. The cell programming is inverted with respect to a desired programming only in specific sets where the desired programming would result in a number of programmed cells greater than the number of unprogrammed cells, the logic state provided by the sense amplifiers associated with the specific sets being inverted.

ROM with a reduced static consumption

A ROM including columns of memory cells connected by columns to respective bit lines; a reference bit line; charge transistors controllable by a common charge line and respectively connecting the bit lines and the reference bit line to a high supply potential. The reference bit line is associated with a column of unprogrammed cells, and the memory includes means for activating the charge line before activation of a word line, the duration between the activation of the charge line and the activation of the word line, and the features of the charge transistors, being chosen so that the level variation of the bit lines is low as compared to the level of the high supply potential.

Low consumption ROM

A circuit for measuring a propagation time of an edge of a signal between an input and an output of a logic cell. The circuit includes a plurality of logic cells of a first type that are electrically coupled in a series, and a plurality of multiplexers, each having a selection input, first and second data inputs, and an output. Each of the plurality of logic cells has a first input and an output, the output of each logic cell in the series being respectively electrically coupled to the first input of a next logic cell in the series. The output of a last logic cell in the series is electrically coupled to the first input of a first logic cell in the series to form a ring. The selection input of each multiplexer of the plurality of multiplexers is electrically coupled to the output of one logic cell in the series, with the output of each multiplexer being electrically coupled to the first input of the next logic cell in the series. The first and second data inputs of each multiplexer are set to different states. Embodiments of the present invention can be used to determine propagation times for each arc of a logic cell and to validate temporal models of logic cells in the context of a logic simulation with delay back annotation.

Circuit for validating simulation models

The present invention relates to an integrated circuit including at least one logic circuit, able to operate at a first operating frequency, and a clock distribution circuit, the clock distribution circuit receiving a first clock signal and providing to the logic circuit a second clock signal, generated from the first clock signal, the frequency of the second clock signal being substantially equal to the first operating frequency. The clock distribution circuit includes a frequency multiplying circuit for generating the second clock signal, so that the frequency of the first clock signal may be lower than the first operating frequency to reduce or minimize the power consumed by the clock distribution circuit.

Growing community of inventors

Saint Vincent de Mercuze, France

Stéphane Hanriat

Growing community of inventors

Saint Vincent de Mercuze, France

St&eacute;phane Hanriat

Stéphane Hanriat