Abstract: The number of input latching comparators in a flash analog-to-digital converter is significantly reduced by merging the input latching function into exclusive OR gates used in the converter's decoding section. A latching exclusive OR gate used for this purpose employs resonant tunneling diodes as the latching devices, with hysteresis and impedance elements connected to ensure that the gate latches in a logic state that corresponds to the input analog signal. The latching logic gates operate in a current mode, enabling updated logic states to be latched in response to a periodic clock signal.

Abstract: A new type exclusive-OR gate and an inverted type selector are composed using a cascaded connection of two p-type MOSFETs between a positive terminal of a power supply and an signal output terminal, and a cascaded connection of two n-type MOSFETs between a grounded terminal of the power supply and the signal output terminal. Power consumption in the new type exclusive-OR gate and the inverted type selector is reduced by reducing number of conventional inverters used in these circuits. A full-adder and a 4-2 compressor are designed using these new type exclusive-OR gates and inverted selectors or an inverted type selector.

Abstract: The gates (11) of the exclusive OR type having two inputs (A, B) are disposed in tree structure in successive layers of an integrated circuit beginning with an input layer which receives the input signals of the tree. The output of each gate is connected to an input of a gate in the adjacent layer. Each gate includes two cells (11a, 11b) that switch substantially simultaneously in response to two respective complementary signals (A, NA; B, NB) from one of the two inputs and that supply respective output signals that are representative of the complementary functions (XOR, NXOR) of the exclusive OR type. This makes it possible to obtain propagation times that are perfectly equal whatever the active input of the tree or the edge to be propagation times that are perfectly equal whatever the active input of the tree or the edge to be propagated may be.

Abstract: A logic signal validity verifier for use in determining the validity of the logic states of a group of logic signals includes an inactive signal fault monitor for determining when all of the logic signals are in an inactive signal state and an active signal fault monitor for determining when more than one of the logic signals are in an active signal state. Where the logic signals are differential, the logic signal validity verifier further includes a differential signal fault monitor for determining when corresponding pairs of the differential logic signals are in the same active or inactive signal state.

Abstract: A static XOR gate is provided with circuit speeds necessary to meet the increasing demand of higher computer clock frequencies. The XOR of the present invention takes up less area and consumes less power than prior art XOR circuits. Furthermore, time XOR gate of the present invention is fully static and imposes less constraints on the circuit designer, e.g. no reset logic, input synchronization, or the like. The circuit utilizes only NMOS transistors in the functional logic portion with two output inverters. The circuit elements are symmetrical and have identical input loading, output drive and propagation paths. The XOR of the present invention allows multiple gates to be connected in stages as a "tree" configuration by providing a "push-pull" XOR/EQV (equivalent, i.e. time complement of the XOR output or XNOR) function which is buffered by output inverters to "push" the output to a next stage.

Abstract: An element generator for a dither matrix comprises a logic device which receives a row address and a column address and performs a logic operation thereon so as to produce a dither element corresponding to the row address and the column address, which is implemented at low cost and has an advantage in that the processing speed is increased. The dithering apparatus comprises a dither-matrix element generator, a comparator, an adder and a selector. The comparator compares the output of the dither-matrix element generator with lower-bit data of the original image data. The adder adds a predetermined number to upper-bit data of the original image data. The selector selects one between the upper-bit data and the adder output, in accordance with the output of the comparator, so as to produce the selected one as the dithered image data. Dithering is thereby performed via hardware, which leads to an increased processing speed.

Abstract: A control circuit for a multiplexer includes two inverters, and exclusive-NOR gate, and a d-type flip-flop. The multiplexer has two input terminals and two selection terminals, and the control circuit has two input terminals. One of the two inverters is connected in circuit between one of the two control circuit input terminals and one of the two multiplexer input terminals; the d-type flip-flop is coupled to the two multiplexer selection terminals; the exclusive-NOR gate is connected in circuit between the two control circuit input terminals and two of three input terminals of the d-type flip-flop; and the second inverter is connected in circuit between the exclusive-NOR gate and one of the three input terminals of the d-type flip-flop.

Abstract: A logic circuit includes a differential amplifier circuit to which a first input signal and a second input signal both of which are complementary are to be supplied, having a circuit for outputting a first output signal and a second output signal both of which are complementary, the first and second output signals depending on a difference between the first and second input signals, an output terminal, and a switching circuit for, based on a first switching signal and a second switching signal which are complementary, performing a switching operation so that either the first output signal or the second output signal is selected as a signal supplied to the output terminal, wherein the signal supplied to the output terminal is a result of an logical operation of the first input signal and the first switching signal. A current sense amplifier may be substituted for the differential amplifier.

Abstract: An arithmetic and logic unit is provided with a first NAND gate (29) which outputs a NAND logic operation result between a first operand (A.sub.i), a second operand (B.sub.i) and a first control signal (S.sub.0), a first EXOR gate (30) which outputs an EXOR logic operation result between the output of the first NAND gate (29) and a second control signal (S.sub.1), an OR gate (31) which outputs an OR logic operation result between the first operand (A.sub.i) and the second operand (B.sub.i), a second NAND gate (32) which outputs a NAND logic operation result between the output of the first EXOR gate (30) and the output of the OR gate (31), a third NAND gate (20) which outputs a NAND logic operation result between a third control signal (S.sub.2) and a carry input (CY.sub.

Abstract: Apparatus for generating an output signal in response to the change in state of any one of a plurality of input signals. The apparatus includes decoding means for each possible combination of input signals, and by an appropriate arrangement of these decoding means, ensures that any change in input signal status causes an output signal to be generated by the arrangement of decoding means. The decoding means includes first and second arrays 10,12, each comprising a matrix of MOS FET's; the FET's 30.sub.ij of the first array 10 are p-channel devices and the FET's 32.sub.ij of the second array 12 are n-channel devices. The matrix of each array is a paralleled configuration of series-connected branches of FET's functioning as decoders. The branches of each array decode input signal combinations of minimum distance two from one another. Arrays 10 and 12 are interconnected in such a manner that they draw no dc current (other than device leakage current).

Abstract: A comparator for comparing the voltages of an address pair signals in complement with the voltages of bit pair signals in complement includes a pair of transistors for receiving the bit pair signals and a pair of MOSFETs for receiving the address pair signals. One transistor and one MOSFET are connected in series to define a first current path and other transistor and other MOSFET are connected in series to define a second current path. When the address signal and the bit signal are the same, both the first and second current paths close, but when they are different, either the first or the second current path opens to permit a current to pass therethrough. By detecting the current in the path, the coincidence and non-coincidence between the address pair signals and bit pair signals are detected.