International Business Machines Corporation

Gerard Boudon

Pierre B Mollier

Pascal R Tannhof

Andre R Steimle

Bernard A Denis

David Pereira

Ieng Ong

Didier Malcavet

Franck Wallart

Seiki Ogura

Anthony Gus Aipperspach

Nghia Van Phan

Allan Harvey Dansky

Steven John Zier

Francis Bredin

Jean-Paul J Nuez

Dominique M Omet

Armand Brunin

Jean-Luc Peter

Adrian Zuckerman

Martine Bonneau

Biagio Pluchino

Michel G Bauge

Jean-Claude Le Garrec

Frank Wallart

Jean-Michel Proust

Virginie De Grivel

Gerard Lebesherais

Yiannis J Yamour

Philippe Stoppa

A self-synchronizing data bus analyzer is provided which can include a generator linear feedback shift register (LFSR) to generate a first data set, and can include a receiver LFSR to generate a second data set. The data bus analyzer may also include a bit sampler to sample the first data set received through a data bus coupled to the generator LFSR and output a sampled first data set. A comparator can be included to compare the sampled first data set with the second data set generated by the receiver LFSR and provide a signal to the receiver LFSR to adjust a phase of the receiver LFSR until the second data set is substantially the same as the first data set.

Self-synchronizing bit error analyzer and circuit

A self-synchronising data bus analyser comprising a generator LFSR, a receiver LFSR and a comparator

Self-synchronising bit error analyser and circuit

An interrupt masker for use in an interrupt handler which receives interrupt request signals in the form of edge detection or level assertion is disclosed. The interrupt masker comprises interrupt detection means for detecting edge transitions of interrupt request signals. The interrupt masker also comprises a polarity detection means for detecting edge transitions of a polarity control signal which is inverted for each inversion polarity request. A filtering means which is coupled to the interrupt detection means and to the polarity detection means generates an interrupt request pulse according to the assertion of the polarity control signal. The interrupt request pulse is generated in response of either rising or falling edge transitions of the interrupt request signal.

Interrupt masker for an interrupt handler with double-edge interrupt request signals detection

Multi-emitter BICMOS logic circuit family with superior performance

The present logic circuit family is derived from the conventional DCCS logic circuit family. The logic circuit shown in the attached drawing is a six-input AND/NAND. It includes: a logic tree (41) comprised of bottom, middle, and top stages (44, 45, 46) cascoded and dotted at the tree output nodes (OUT, OUT) to perform a determined logic function (F, F). The top stage (46) includes a current switch (49) formed by a pair of input transistors (TX431, TX432) connected in a differential amplifier configuration. The base of one input transistor (TX431) on the left side of the tree is connected to the output of an AND gate, which consists of input diodes (D431, D432, . . . ) and resistor (RD41). True (IN PHASE) logic input signals (Z41, Z42, . . . ) are ANDed in this AND gate and a first elementary output signal, is available at the common emitter node (CN43) of the said differential pair. On the right side, additional inpout transistors (TX433, . . . ) are paralleled with the other input transistor (TX432) of the differential pair, so that the complementary (OUT OF PHASE) input signals (Z41, Z42, . . . ) that drive the transistors, are ORed to deliver a second elementary output signal, complementary to said first elementary output signal, on said common emitter node (CN43). Same principle applies at the first and second levels to build the bottom (44) and middle (45) stages. The present invention allows to increase the number of logical inputs to be applied to a DCCS logic circuit, and in turn, the number of logic functions performed in the logic DCCS tree. As a result, an extended library of DCCS logic circuits may be obtained.

Differential cascode current switch (DCCS) logic circuit family with

The present invention relates to fast complementary emitter follower drivers/buffers to be used in either a CMOS or pure complementary bipolar environment. The output driver (22) comprises top NPN and bottom PNP output transistors (T1, T2) with a common output node (N) connected therebetween. A terminal (15) is connected to the said output node (N) where the output signal (VOUT) is available. The pair of bipolar output transistors is biased between the first and second supply voltages (VH, GND). The output driver is provided with a voltage translator circuit (S) connected between the base nodes (B1, B2) of the output transistors (T1, T2). Logic signals (IN1, IN2), supplied by a preceding driving circuit (21), are applied to said base nodes. According to the invention, the voltage translator circuit (S) comprises two diodes (D1, D2) connected in series, preferably implemented with a main bipolar transistor having a junction shorted by a diode connected transistor to form a Darlington-like configuration. As a result, the voltage shift VS between the base nodes is selected to have the said output transistors operating at an operating point which ensures minimum delay and power consumption. In a typical bipolar technology, VS is made to be approximately equal to 1.5V. Additional features comprise the connection of a capacitor (C) between the base nodes and resistances (R1, R2) to the base nodes. The preceding driving circuit may be a CMOS logic gate or an ECL logic circuit.

Complementary emitter follower drivers

According to the present invention, a CMOS interface circuit (C2) similar to a latch made by two CMOS cross coupled inverters (INV1, INV2) is placed directly on the output node (14) of conventional BICMOS logic circuit (11) operating alone in a partial swing mode. This latch is made of four FETs P5, P6, N8, N9 cross-coupled in a conventional way with the feedback loop connected to said output node (14). The partial voltage swing (VBE to VH-VBE) naturally given by the output bipolar transistors (T1, T2) mounted in a push pull configuration is reinforced to full swing (GND to VH) by the latch at the end of each transition. The state of the output node if forced by the latch because of the high driving capability due to the presence of said output bipolar transistors (T1, T2). As a result, the improved BICMOS logic circuit (D2) has an output signal (S) that ranges within the desired full swing voltage at the output terminal (15). It is a characteristic of this embodiment that the structure of CMOS interface (C2) is always independent of the logic function implemented in the conventional BICMOS logic circuit (11). More generally, the CMOS interface circuit may have various physical implementations, however, it is always comprised of CMOS FETs and it becomes active at least in one of the GND to VBE or (VH-BE) to VH range.

BICMOS logic circuit with full swing operation

The invention provides novel implementations of a latch cell in CMOS gate array technology to produce latch dissymmetry and permit a single ended data input. The dissymmetry is produced by increasing the output impedance of the second stage of the latch cell, which can be done, either in a DC or in an AC mode, or even in a mixed version of both modes.

Latch cell family in CMOS technology gate array

A DTT type basic logic circuit exhibiting improved immunity to noise and including input diodes for receiving input signals A, B, . . .; an input transistor the emitter of which receives an additional input signal X and the base of which is connected to the anodes of the input diodes; and an output inverter transistor disposed so that the signal at the output thereof represents the logic function X(AB . . .). From this circuit, a family of logic circuits suitable for realizing very-large-scale-integration logic networks in a master slice can be developed. The master slice comprises general-purpose cells in which pre-diffused semiconductor elements can be interconnected to form the desired circuits.

Logic circuits for forming VLSI logic networks

Duplicated circuit arrangement comprising a main processor (30) and its P bit data bus (44), and two identical redundant devices (21:22), each device is comprised of a processing element (23;35) performing the same task in parallel on a P bits word, and send/receive circuits (24,25;36,37) controlled by the main processor through lines (SR11 to SR22) to transmit said word to and from said main processor. For each device, the send/receive circuits are split into two parts. Send/receive circuit of the first device (21) is split in two parts (24, 25); the first part (24) handles the P/2 Most Significant Bits (MSB's) and the second part (25) handles the P/2 Less Significant Bits (LSB's). In normal operation, during the transmission step, only the first part (24) is allowed to send bits on one half (33) of the data bus (44). Symmetrically send/receive circuit of the second device (22), is also split in two parts (36, 37); the first section (36) handles the P/2 Most Significant bits (MSB's) and the second part (37) handles the P/2 Less Significant Bits Z(LSB's); only the second part (37) is allowed to send bits on the other half (34) of the data bus (44). Therefore, the data bus driving effort is equally shared between the two devices, the maximum number of simultaneous switching is P/2 for each device. This reduction allows greater transmission speed on large busses.

Duplicated circuit arrangement for fast transmission and repairability

In the transmitting chip, the bits are serialized and applied to a coding circuit in which bit stream (D) and its complement (D) are transformed into two signals (PH1 and PH2) under the control of a saw-tooth clock signal CK'. Signals (PH1 and PH2) are sent to the receiving chip, wherein they are applied to a decoding circuit which generates two signals (DJ) and (DK) representative of the data bits and a recovered clock signal CLK. The three signals (DJ, DK and CLK) as well as a frame signal (F) are used by a converting and demultiplexing circuit for assembling bytes of parallel data bits.

Chip to chip information bit transmission process and device

A word line selection circuit includes a conventional Schottky diode decoder and a driver transistor which is connected to a word line. A word line is selected when the transistor is conductive and all associated diodes of the decoder are off. The base current of the driver transistor is defined by a control transistor whose conductivity is opposite to that of the driver transistor and which applies the selection current to the base of the driver transistor. A regulating transistor forms a current mirror with the control transistor to regulate the selection current. A compensation circuit associated with the regulating transistor modulates the collector current of the regulating transistor as a function of the driver transistor factor.

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Mennecy, France

Gerard Boudon