International Business Machines Corporation

Other

Bernard A Denis

Pierre B Mollier

Gerard Boudon

David B Eardley

Pierre Coppens

Pierre-Yves Urena

Chekib Akrout

Dominique M Omet

Armand Brunin

Virginie De Grivel

Philippe Stoppa

In combination with an electronic memory of the type having a plurality of memory cells (CA, . . . CN) connected between two bit lines (BLT, BLC) having inherent bit line capacitances (C1, C2), there is disclosed an improved sense amplifier (15) comprised of two stages. A first stage (16) includes a first clocked latch (5) having an enable device (T5), gated by a first control signal (SSA) and bit switches (T6, T7) connected between the common nodes (6, 7) of said first clocked latch and said bit lines, and gated by a bit switch control signal (BS) to provide an output signal on first data lines (DLT, DLC). A second stage (17) includes a second clocked latch (20) having an enable device (T24) gated by a second signal (SL) and data switches (T28, T29) connected between second data lines (DT, DC) at the same potential as data output nodes (21, 22) of said second clocked latch and said first data lines (DLT, DLC). Said data switches (T28, T29) are gated by a data switch control signal (DS) which is derived from the bit switch control signal (BS), so that the first and second stages (16, 17) operate sequentially to amplify the data continuously along the sensing chain of the data path during a READ operation to provide a data output signal on said data output nodes. The data is then available for further processing at the output terminal (24) of the output driver (23).

Double stage sense amplifier for random access memories

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

A semiconductor memory device including a pair of bit lines (BL, BL) having relatively high stray capacitances (C1, C2), a word line (WL), and a memory cell (MC1) connected to the bit lines and word line for selection by an address signal, and a restore circuit comprising a coupling/equalizing circuit (12) controlled by a BLR clock and a reference voltage generator (51) for quickly restoring the bit lines. The reference voltage generator (51) comprises both static and dynamic current sources. The static current source consists of a small N MOS transistor (N52) operating as a resistor load, while the dynamic current source consists of at least one small P MOS transistor (P'53, . . . ), connected in parallel with the N MOS transistor, and gated with a clock (BCC', . . . ) derived from the BLR clock, so that the P MOS transistor is turned ON during the restore time. An additional N device (N54) may be inserted between the reference line (RL) and ground (GND). The improved reference voltage of the present invention significantly reduces both consumed silicon area and restore time.

Reference voltage generator for CMOS memories

Memory comprising a matrix of conventional Harper pnp cells and peripheral circuits which allows it to be used either as a random access memory or as an associative memory. In addition to the read/write circuits which are inhibited in search mode, it comprises search mode control circuits 7-1 to 7-m to provide the memory cells with a search argument DI-1 to DI-m and search circuits 11-1 to 11-n connected to the word lines for detecting the match or mismatch conditions. A search restore circuit 15 common to all word lines WL is used to restore the work lines to a quiescent voltage once the search operation is completed. Circuits 7 and 11 are inhibited in read/write mode.

Memory using conventional cells to perform a ram or an associative

At least one target (10, 11) is caused to move with complex motion combining rotation about an axis (5) which is approximately horizontal and translation along a direction which is approximately perpendicular to said axis (5) behind an opaque panel (3) delimiting a window (4). By giving suitable directions, amplitudes and speeds to these respective motions, the apparent motion of the target as seen through the window (4) is pseudo-random in time and concerning its trajectory between two passes behind the panel. This increases the difficulty, and hence the attraction of target shooting.

Apparatus for presenting a target at a window

Two memory cells each can be entirely fabricated in only two isolation beds. In one embodiment each bed contains one lateral PNP and one vertical NPN transistor in a merged structure. To obtain faster switching speeds, the PNP transistors are cross-coupled as flip-flop transistors while the NPN transistors act as load transistors. A word select signal is applied to forward bias the base-emitter junctions of the NPN load transistors, to thereby generate a potential difference between bit lines coupled to the emitters of the PNP flip-flop transistors.

Random access memory cell

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.

Decoding and selection circuit for a monolithic memory

Two memory cells each can be entirely fabricated in only two isolation beds. In one embodiment each bed contains one lateral PNP and one vertical NPN transistor in a merged structure. In a second embodiment, each bed contains one lateral PNP and two vertical NPN transistors in a merged structure. Memory access circuitry provides a high ratio of selected to unselected cell current in order to permit fast memory operation.

A five device RAM cell comprising a four device Merged Transistor Logic (MTL) cell plus a separate sense line and a fifth bipolar transistor device having a collector connected to one node of the cell, a base connected to the other node of the cell, and an emitter connected to the sense line.

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Mennecy, France

Bernard A Denis